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This article appeared in a journal published by Elsevier. The attachedcopy is furnished to the author for internal non-commercial researchand education use, including for instruction at the authors institution
and sharing with colleagues.
Other uses, including reproduction and distribution, or selling orlicensing copies, or posting to personal, institutional or third party
websites are prohibited.
In most cases authors are permitted to post their version of thearticle (e.g. in Word or Tex form) to their personal website orinstitutional repository. Authors requiring further information
regarding Elsevier’s archiving and manuscript policies areencouraged to visit:
Paolo Bellavite1,*, Marta Marzotto1, Debora Olioso1, Elisabetta Moratti1 and Anita Conforti2
1Department of Pathology and Diagnostics, University of Verona, Strada Le Grazie 8,37134 Verona, Italy2Department of Public Health and Community Medicine, University of Verona, Piazza L.A. Scuro 10,37134 Verona, Italy
The pharmacodynamics aspects of homeopathic remedies are appraised by laboratory
studies on the biological effects at various levels (cellular, molecular and systemic).
Themajor question is how thesemedicinesmaywork in the body. The possible answers
concern the identification of biological targets, themeans of drugereceptor interactions,
themechanisms of signal transmission and amplification, and themodels of inversion of
effects according to the traditional ‘simile’ rule. These problems are handled by two
experimental and theoretical lines, according to the doses or dilutions considered
(low-medium versus high dilutions). Homeopathic formulations in low-medium dilu-
tions, containing molecules in the range of ultra-low doses, exploit the extreme sensi-
tivity of biological systems to exogenous and endogenous signals. Their effects are
interpreted in the framework of hormesis theories and paradoxical pharmacology. The
hypotheses regarding the action mechanisms of highly diluted/dynamized solutions
(beyond AvogadroeLoschmidt limit) variously invoke sensitivity to bioelectromagnetic
information, participation of water chains in signalling, and regulation of bifurcation
points of systemic networks. High-dilution pharmacology is emerging as a pioneering
subject in the domain of nanomedicine and is providing greater plausibility to the puz-
zling claims of homeopathy. Homeopathy (2013) 103, 22e43.
Keywords: High dilutions; Homeopathic potencies; Hormesis; Nanopharmacology;Biophysics; Systems biology; Water clusters; Water coherence domains; Similia rule
IntroductionHomeopathy is progressively receiving scientific valida-
tion but a series of theoretical and technical questions needstill to be clarified, since several problems appear to distin-guish this discipline from conventional pharmacology. Thephysicochemical nature of the homeopathic remedies,which are produced according to a peculiar method of se-rial dilution followed by ‘dynamization’, was dealt within a previous paper.1 Here the recent advances concerningthe possible mechanism of actions of these drugs in thebody are reviewed. Pharmacokinetics is the branch of phar-
macology dedicated to the determination of the fate of sub-stances administered to a living organism up to the point atwhich they are completely eliminated from the body. Thisapproach is often studied in conjunction with pharmacody-namics, the study of effects on the body. Highly dilutedmedications, including those produced according to the ho-meopathic pharmacopoeia, are hardly suitable to pharma-cokinetic investigation, due to the lack of analyticalmethods having sufficient sensitivity. On the other hand,experimental evidence from clinical and laboratory studiesis providing a remarkable contribution to pharmacody-namics of this class of remedies. The question of how thesemedicines may work concerns the identification of biolog-ical targets at various levels (cellular, molecular and sys-temic), the ways of drugereceptor interactions, themechanisms of signal transmission and amplification,and the ‘simile’ rule (see Table 1). All these problemshave several aspects, that can be considered according tothe different doses and/or dilutions employed.
DOI of original article: http://dx.doi.org/10.1016/j.homp.2013.08.003.*Correspondence: Paolo Bellavite, Department of Pathology andDiagnostics, University of Verona, Strada Le Grazie 8, 37134 Ver-ona, Italy.E-mail: [email protected] 31 July 2013; accepted 12 August 2013
Homeopathy (2014) 103, 22e43� 2013 The Faculty of Homeopathy
http://dx.doi.org/10.1016/j.homp.2013.08.002, available online at http://www.sciencedirect.com
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Pharmacologicactivityofmother tincturesandof lowpotencies(e.g., 2Ce3C,containing relativelyhighdosesofactiveprinciples)poses no problems of interpretation and requires analysis of thecomponents and identification of their targets in the organism, ina way not dissimilar from that of herbal products, snake toxins,or mineral oligoelements. The action of medium potencies, thatcontain ultra-low doses of active principles (ULDs, namely from4Ce5Ctoapproximately12C,close to theAvogadroeLoschmidtlimit) entails high sensitivity of living organisms and inversion ofdrug effects, in the framework of models not much distant frommodern pharmacology, like hormetic mechanisms. The action ofhigh dilutions (HDs, namely homeopathic dilutions beyond theAvogadroeLoschmidt constant) requires the identification ofpossible ‘non-molecular’ or ‘meta-molecular’ information transfermechanisms. Finally, the ‘holistic’ approach of homeopathy ashealing systemgoes far beyond the identification of specific infor-mationtransfermechanismsormolecular targetsandshouldbeun-derstood in the light of systems biology.
Biological targetsThe specificity of any drug effect is based on the interac-
tion or active principles with their biological targets and thesame can be conceived for homeopathic drugs. In the lattercase, the identification of these interactions is complicatedby several factors, including the different nature of rem-edies in low and high potencies, the presence of manyactive principles in most compounds of vegetal or animalsources, and the different sensitivities that presumablyexist in healthy and sick organisms. In spite of these prob-lems, experimental evidence gathered in laboratory studieshas identified a representative number of cell and molecu-lar targets of homeopathic drugs.
Local targets
The cornerstone of homeopathy that the whole clinicalpicture is considered on an individual basis is not indispute, but laboratory models show that mechanism(s)of action of the drug can be investigated in animals, cells,tissues, and even at the molecular level. Pharmacodynamiceffects of homeopathic remedies have been proven inseveral dozens of animal and ‘in vitro’ laboratory studies.Apart from reviews on this topic,2e5 some recentdemonstrations of these effects merit to be mentioned.One of the most interesting lines of research regardedhistamine and other compounds (Lung histamine andApis mellifica), which have pro-inflammatory effectswhen used at high doses but trigger anti-inflammatorymechanisms when employed at ULDs and HDs. The effectof Lung histamine (5C and 15C) and Apis mellifica (9C),traditional remedies used for the treatment of allergic dis-eases, was assessed on in vitro human basophil degranula-tion.6 After this early study, several independentlaboratories reported a significant inhibition of basophilfunctions by HDs of histamine. Most studies were pos-itive7e14 with few exceptions.15,16 The effectwas inhibited by histamine H2 receptor antagonistscimetidine,17 supporting the hypothesis that HDs of hista-mine exert their inhibitory power at the level of H2 recep-tors of basophilic cells. That homeopathic drugs may actthrough modulation of cell receptors and protein synthesisis supported also by studies from the laboratory of Khuda-Bukhsh.18 In a model of chemically induced murine papil-loma, where a known set of proteins involved in the tumordevelopment were altered, the researchers found a signifi-cant remodulation toward normal condition after treatmentwith the potentized drug Secale cornutum 30C, driven by
Table 1 Aspects of homeopathic pharmacodynamics
Aspect Medium potencies (ultra-low doses) High potencies (high dilutions)
Nature of the medicinea Very low concentrations of active moleculesNanoparticles
Inversion of effects (the ‘Simile’) HormesisDual receptorsGating by cAMPHspsParadoxical pharmacology
Rebound in timeSystems biology theoriesCoherent response to stress
a This aspect was the subject of the preceding paper.1
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the downregulation of aryl hydrocarbon receptor, as evalu-ated by western blot analysis.A large series of studies by an Austrian group19e21
showed the influence of highly diluted thyroxine (30D)on the spontaneous tendency of juvenile frogs, at the endof metamorphosis, to leave the water and climb ontoland. Climbing activity diminished under the influence ofdilution thyroxine 30D, with statistical significance.These results show that HDs of thyroid hormones, that atphysiologic doses stimulate growth and metamorphosis,transmitted inhibitory information to the same testsystem, even though the molarity was beyond Avogadro’sconstant. This effect was confirmed by independentlaboratories, with various experimental approaches.22e24
Evidence from laboratory,25 animal,26 and clinical27
studies showed that the immune system, inflammationmechanisms and leukocytes are among the targets of ho-meopathic effects. Low potency formulations composedby Arnica montana 4D, Calendula officinalis 4D, Hyperi-cum perforatum 4D and Symphytum officinale 6D, clini-cally used for wound healing, exerted in vitro stimulationof fibroblasts, which are the cells responsible of connectivetissue repair.28 Another low potency formulation contain-ing Arnica montana and other plant extracts and mineralswas tested on an animal model of traumatic inflamma-tion.29 The decrease of paw oedema, associated with theprocess of healing, was more rapid in verum-treated thanin placebo-treated rats and the therapeutic effect was asso-ciated with a significant decrease of interleukin-6. The ef-ficacy of the complete formulation was higher than thecombination of a selection of active components, suggest-ing that its effect cannot be considered as the ‘sum’ of itsactive components and probably a synergistic interactionoccurs to determine the final effect. The effects of Arnicamontana 6C on the modulation of acute inflammation ki-netics in rats were evaluated by another group.30 Medium(6C) and high (12C, 30C, 200C) potencies of Mercuriussolubilis added to mice’s drinking water for 7 days(in vivo treatment) modulated macrophage functions.31
Similar effects were observed also when the same drugwas added to the cell culture, suggesting that the observed‘in vivo’ effect was due to a direct interaction with macro-phages. Interestingly, another group used Mercurius solu-bilis in a rat model of wound healing, showing that ratstreated for 21 days with a 12C potency had less wound in-fections than placebo-treated rats.32 In animal models, alsoSilica, which is a stimulant of macrophages and fibrous tis-sue formation at high doses, stimulates tissue healing andmacrophage activation also at extremely low (homeopath-ic) doses.33,34
Ignatia, Gelsemium, Chamomilla (in homeopathic dilu-tions/potencies) have consistently shown to act on the ner-vous system and specifically to modulate anxiety-likebehaviours in rodents.4 In the traditional Materia Medicaand homeopathic literature, Gelsemium is described as aremedy for a variety of anxiety-like psychological and be-havioural symptoms.35e38 All parts of the plant containthe major active principle gelsemine as well as other toxicstrychnine-related alkaloids, such as gelseminine and sem-
pervirine.39,40 The anxiolytic, antidepressant and/oranalgesic action of Gelsemium extracts and of gelseminehas been recently demonstrated in animal models.4,41e44
A hypothetical target of Gelsemium has been suggested bystudies showing that gelsemine stimulates the biosynthesisof allopregnanolone (an anti-stress neurosteroid) in the ratbrain,45,46 but probably other mechanisms of thepharmacodynamic action may exist.4 The effects of Gelse-mium are not restricted to the nervous system, as shown byother reports indicating that this plant species may exhibitanticancer and immunomodulation activities.47e50 The‘Gelsemium model’ e encompassing experimental studiesin vitro and in vivo from different laboratories and withdifferent methods, including significant effects of its majoractive principle gelsemine e may play a pivotal rule forinvestigating the pharmacodynamics mechanisms ofhomeopathic remedies.
Effects on gene expression
The ability of high diluted compounds to modulate geneexpression in human and unicellular organisms has beenobject of investigations. In early studies with the isopathicmodel of arsenicum-intoxicated mice, the failure to expressthe protective effect of Arsenicum album 30C and 200C inthe presence of the transcription blocker Actinomycin D51
suggested that potentized homeopathic drug acted throughactive gene transcription. Then, in experiments conductedin biological models (arsenite or UV treated E. coli andSaccharomyces culture) the treatment with Arsenicumalbum 30C or Arnica montana 30C modified the expres-sion of specific genes that are target respectively of thearsenite and UV irradiation injure.52,53 In recent studies,the same group evidenced the anti-tumorigenic effects ofmother tincture drugs (quercetin, gingerol and Hydrastiscanadensis), as demonstrated by the modulation of theexpression of specific mRNA markers of apoptosis andby cell viability tests. Moreover, they demonstrated a directinteraction between the cell DNA and the drug itself, asobserved by circular dichroism (CD) spectropolarimetricstudy and DNA melting analysis.50,54,55 These findingssupport the hypothesis that homeopathic remedies couldturn on or off some relevant genes, initiating a cascade ofgene actions to correct the gene expression that wentwrong to produce the disorder or disease. In thishypothesis the target relevant gene should be sensitive tosimilar stimuli and exert a pleiotropic transcriptionalregulation on a battery of genes with correlated functions.The analysis of gene expression was performed on large-
scale by some authors, using the microarray technique.This method is based on microscopic arrays of immobi-lized nucleic acids (about 15e30,000 genes dependingon the type of platform), that function as probes forsequence-specific nucleic acid hybridization. de Oliveiraet al.56 investigated the effects of a complex homeopathicmedication (Aconitum 11D, Thuja 19D, Bryonia 18D, Ar-senicum 19D and Lachesis 18D) on cytokine productionand gene expression from mice macrophages. They foundthat the verum-treated group differentially expressed 147
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genes (45 upregulated and 102 downregulated) whencompared to the placebo-treated group. These genes aremainly involved in transcription/translation, cell structureand dynamics, immune response, cytoprotection, enzy-matic process, and receptors/ligands.Bigagli et al. evaluated the effects of extremely lowcopper
concentrations (from 10�6 to 10�17 M) on gene expressionprofiles of a line of human prostate epithelial cells.57 Micro-array data demonstrated that copper added to the mediumvaried gene expression at all concentrations tested. Unfortu-nately, the authors did not declare if the solutions were suc-cussed after dilution and if can be considered ashomeopathic preparations. However, an interesting indica-tion is that the effect was not dose-dependent, but followeda sinusoidal behaviour, since about 12.5%, 14%, 5.5%,15% and 7.5% of the genes were modulated by copper10�6 M, 10�9 M, 10�12 M, 10�13 M and 10�17 M, respec-tively. Moreover, there were clusters of genes overexpressedor downregulated at all concentration and other clusters thatwere upregulated only in the low or high range on copper di-lutions.A recent study proved the effects of homeopathic medi-
cines (Ruta 200C, Carcinosinum 200C, Hydrastis 200C,Thuja 200C) onDalton’s lymphoma tumor cells.58 In partic-ular they measured the apoptosis and the expression of spe-cific genes, by reverse transcription polymerase chainreaction (RT-PCR) andmicroarray. In these experiments dy-namized preparations showed significant cytotoxic actionagainst cancer cell lines, and at times, the activitywas higherfor 200C potency than for the mother tincture. By the RT-PCR method, the expression of the apoptotic genes p53,Bcl-2, and caspase 3 after incubation with the ultradilutedremedies was investigated. Not all the potentized drugsinduce expression of all themarker genes, but onlyCarcino-sinum 200C induced p53 gene expression.Moreover,micro-array analysis showed a direct action of ultradilutedsolutions on gene expression: about 100 genes were differ-entially expressed with the potentized drugs, while about600 with Thuja 1M, compared to controls. A comparisonof potentiated drugs with their mother tincture indicatedthat the potentiated drugs have biological activity similarto that of their mother tincture in spite of ultradilution.Our preliminary results reveal the extremely high sensi-
tivity of human neurocytes gene network to ULDs and HDsof Gelsemium.59 As observed by microarray technique, thedrug modulates the expression of a series of genes involvedin neuronal function compared to the control vehicle solu-tion. 24 h exposure to the Gelsemium s. 2C dilution (thelowest potency employed, corresponding to a gelsemineconcentration of 6.5 � 10�9 M) significantly changed theexpression of 56 genes, of which 49 were downregulatedand seven were overexpressed. Several of the downregu-lated genes belonged to G-protein coupled receptor signal-ling pathways, calcium homeostasis, inflammatoryresponse, and neuropeptide receptors. Several genes signif-icantly decreased their expression even after treatment withhigher dilution/dynamization (3C, 4C, 5C, 9C and even30C), although with smaller changes (Marzotto et al., inpreparation).
Systemic targets
The existence of specific cell and molecular targets fordrugs does not mean that the homeopathic effects can beexplained by local interactions only. Although homeopathyis thought to have been born as an empirical approach, it isactually based on a systemic and dynamic view of healthand disease, that can be better appreciated inside the newparadigm of complex systems,60e65 whose key featuresare:
(a) nonlinearity: output is not proportional to input, occur-rence of paradoxical responses;
(b) deterministic chaos: apparently unpredictable behav-iour, sensitivity to initial values and perturbations, frac-tals, self-similarity;
(d) adaptation: evolution, plasticity, memory and learning,hysteresis, sensitization/desensitization, tolerance.These concepts of nonlinear dynamics offer a differentperspective for understanding homeodynamics and dis-ease,66e68 and nonlinear system theories are starting tobe applied to help interpret, explain, and predictbiological phenomena.69
When a stimulus is applied to complex networks in theimmune, endocrine and nervous systems, the entirenetwork responds and undergoes an adaptation. Such a sys-tem is deterministic but extremely sensitive to even smallperturbations. The triggers that cause the immune responseto go in a certain direction depend not just on a singlesignal, but rather on a multiplicity of elements acting oneach other synergistically, antagonistically and throughfeedback loops.70 These features can also be used for thecontrol of chaos and this may open up an avenue for ther-apy, but further models still need to be refined and devel-oped.There is some evidence that HDs applied on the tongue
trigger rapid electrophysiological responses in central ner-vous system.71,72 Rats kept on a high-salt diet were anes-thetized and a microelectrode, connected up to anoscilloscope, was implanted in the lateral hypothalamicarea to record the discharge frequency in that area. Aftera suitable period recording the basal tracing, a few dropsof Natrum muriaticum (sodium chloride or common seasalt) 30C or 200C were deposited on the tongues of therats. The application caused marked changes (reductions)in the discharge frequency of the nerve centre. This exper-iment suggests both that the action of the drug can be medi-ated by the hypothalamic nerve centres and thatpreconditioning with a high-salt diet makes the animalmore sensitive to the remedy Natrum muriaticum. Rapid(few seconds) hypothalamic electrophysiological re-sponses to Nux vomica 200C and 1000C in ethanol-intoxicated rats were also reported.72
Frequency-coded signals
In biology, information transfer does not depend only onthe dose of a signal molecule, but also on the ‘way’
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molecules relate to the receiver systems. For example, cellsare capable of distinguishing the kinetics by which a signalis received, i.e., whether it is a sudden signal or one with aslow onset, whether the concentration is stable or oscil-lating, whether the signal occurs on its own or is accompa-nied by other concomitant or preceding signals, whether itis the first prompting or a repetition of something previ-ously experienced. Thus, the information is not merelyquantitative, but inherently spatiotemporal. Calcium andother intracellular messengers perform their regulatingfunctions by means of oscillations of concentration whichconstitute a kind of ‘digital code’ for the various systemssensitive to them. Such digitally encoded signals couldmore precisely regulate cell responses also through rhyth-mic changes in hormone concentrations.Biological communication is so important that nature
has gone out of its way to devise a wide variety of formsof communication. To those previously mentioned wecan add others, first and foremost among which are thesense organs endowed with photoreceptors, chemorecep-tors, baroreceptors, and others. Bioelectrical signals, en-coded in spatiotemporal changes of membrane potential,regulate cell proliferation, migration, differentiation, andmorphogenesis.73 Sensitization to chemical toxins includesbioelectric disorders and autonomic changes that can be re-vealed by spectral electroencephalography (EEG), bloodpressure, heart rate, and plasma beta-endorphin.74
In order to create a scientific basis of homeopathy andother complementary medicine applications like acupunc-ture, it is certainly necessary to add a more non-localapproach. A possible framework involves oscillatory elec-tromagnetic (EM) interactions as regulatory and e in caseof diseasee deregulatory impulses of the organisms.75 Forinstance: a homeopathic stimulus (Strophantus hispidus30C) changed the power spectrum of heart rate variabilityin healthy human subjects during 24-h long intervals.76
Subsequently the same group used EEG to experimentallyinvestigate the effects of HDs in laboratory rats.77e79 Theytested the effects of Coffea cruda 30C and 200C versusplacebo on the sleep patterns of rats assessed using EEGreadings in the Delta band, 0.5e2.5 Hz, from the parietalregion. Treatments were administered orally at thebeginning of the sleeping period. In synthesis, thespectral power of Delta band was significantly higherthan baseline for Coffea 30C and caffeine (15.5 mg/kg).Coffea 30C and caffeine have similar effects on sleeppattern, enhancing delta power; Coffea 200C appeared toaffect only the synchronization. Another interesting studyregarded histamine.80 Besides being an inflammationmediator, histamine is a central neurotransmitter, it in-creases arousal via H1 receptors. HDs of histamine (30C)decreased the mean Delta band spectral density and the ef-fect was very rapid. Subsequently the same group testeddifferent potencies and found highly nonlinear patterns,with peaks of activity at 15C, 21C and 30C dilutions.81
Following those animal studies, remedy-related sleepstage alterations and EEG changes were detected in humansubjects. In patients with fibromyalgia, the clinicalresponse to homeopathic remedies at a systemic level is
associated with changes in prefrontal electroencephalo-graphic alpha frequency cordance (EEG-C, a correlate offunctional brain activity).82 In a recent experimental trial,college students with a history of coffee-related insomniatook one bedtime dose of a homeopathic remedy (Coffeacruda orNux vomica 30C) and those remedies significantlyaltered short-term nonlinear dynamic parameters of slowwave sleep.65 These observations suggest EEG-C as anearly biomarker of individualized homeopathic medicineeffects. Recently, the same group used EEG to evaluatepsychophysiological effects of two homeopathic remedies(Sulphur or Pulsatilla) after an olfactory activation proto-col on healthy young adults.83
The data showing significant interactions of remedies forEEG parameters encourage additional research onnonlinear psychophysiological and bioelectric effects ofhomeopathic remedies.
Disease dynamics and bifurcation points
The ability of extremely diluted drugs to change thebehaviour of cells, animals and humans can be ascribedto the high sensitivity of the targets involved and to the ex-istence of subtle bifurcation points in the disease dynamics.For example, we have shown that HDs of Gelsemium s.may modulate anxiety in mice, because behavioral testsare designed to put the animal in a situation of uncertainty,regarding the trajectory of movements in an open space.84
In this situation, an extremely small pharmacological influ-ence on emotional state of the animal can determine thechoice of which direction to move, e.g., of whether the an-imal moves toward the open space or along the walls of thetest platform. The sensitivity of laboratory tests (and hu-mans in clinical settings) to minimal factors is also,conceivably, one reason for the high variability of re-sponses in the various experiments and of the experienceddifficulties in full replicability in different laboratories.Far from equilibrium states and bifurcation points are
found at each level of the disorganization of living organ-isms, from molecules to cells, and lead, when not cor-rected, to progression of disease. Here we will outlinesome characterizing bifurcation points in the dynamic pro-gression of diseases, summarizing and updating a theorythat was extensively reported elsewhere.85e87 Accordingto conventional diagnostic criteria, what usually appearsas the ‘disease’ is actually the last phase, consisting ofparticular biochemical and anatomical abnormalities.Prior to this, however, there are at least three otherphases. We have the very first phase in which an initialdisorder, largely non-apparent apart from a few very indis-tinct symptoms or variations in very subtle parameters,makes the body susceptible to perturbation-inducedexternal agents. This stage could for example include peo-ple who are subject to overwork (stress) or to an unbal-anced diet, or those who smoke, are exposed to lowdoses of ionizing radiation, or present particular geneticcharacteristics that make them ‘at risk’. Clearly, at thislevel the balance between normal and pathological isextremely precarious, and the ensuing course of the disease
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can come down on one side or the other, according to shiftsin minor factors.A second bifurcation can be found in the reactive phase
of homeodynamic biological systems (haemostasis,inflammation, tissue regeneration, etc.). These systemsare ‘two-faced’, in the sense that they bring about healingbut may also cause damage, because they can either attackor disorder the host itself. To what extent, in each individ-ual case, the damage done prevails over the reinstatementof health, or vice versa, depends on subtle variations inthe behaviour of the homeostatic system itself. In partic-ular, the fate of the reaction depends on the choice thatthe system has to make between the ‘price to pay’, in termsof toxicity and suffering, and the guarantee of success ofthe operation in terms of survival of the body. A choiceof this type depends both on the local elements involved(receptors, concentration of mediators, presence of exoge-nous chemical substances) and on the type of centralisedcontrol system that coordinates and regulates the variousresponses. Thus, at the level of this bifurcation, theoutcome of the reaction may depend on subtle factorsthat are significant for the coordination of the reactions.A third phase in the disease process, which represents
another critical decision point, is when the reactive systemsfail to cope with the situation and to restore the original
state. At this point a pathological adaptation may set in,meaning a semi-permanent modification which shifts thereceptor sensitivity thresholds and induces furtherbiochemical and anatomical changes. Chronic pathology(‘miasms’ in homeopathic terms) is a dangerous form ofadaptation, which makes it possible to ‘live with’ the ho-meodynamic disorder, but also opens up the way to pro-gression. In fact, a chronically disordered system requireshigh energy consumption and is more susceptible to furtherdamage due to lack of coordination in various defence andhealing systems. Also, the choice between reaction andadaptation is very complex, as it is determined by a multi-plicity of subtle endogenous and exogenous factors.
AmplificationmechanismsThe ‘biological power’ of a drug depends on the affinity
between the binding site and the molecule itself, as well ason the response of the treated system. Note that conven-tional drugs normally act at concentrations between10�6 M (micromolar) and 10�9 M (nanomolar), whereasthe more modern ones such as cytokines are also activeat concentrations from 10�12 M (picomolar) to 10�15 M(femtomolar). In the scientific literature, there are manypublications showing a clear biological effects (meaning
Figure 1 Example of possible signal amplificationmechanisms at the cell level. It is not necessary to involvemany receptors to have a strongeffect, nor is it necessary for the signal to be of a molecular type. Receptor triggering or modulation could also be physicochemical (heat,radiation, vibration, sound waves, or particular structures of water or solvent). cAMP: cyclic adenosine monophosphate (activator of proteinkinase A), Ad-5P: adenosine-5phosphate (hydrolysis product of cAMP).
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that there are demonstrable effects in laboratory systems)of substances diluted by as much as 10�18 M (attomolar),corresponding approximately to the 9C homeopathic dilu-tion.1 The typical physiological levels of the endogenoushormones are extremely low: 10e900 pg/ml for estradiol,300e10,000 pg/ml for testosterone, and 8e27 pg/ml forT4. When the circulating levels in blood are corrected forthe low fraction of the hormones that are not bound toserum binding proteins, the free concentrations that actu-ally bring about effects in cells are even lower, for example0.1e9 pg/ml for estradiol.88
A simple calculation illustrates how these doses pose achallenge to current theories: in fact, a concentration of10�15 M (approximately 5Ce7C in homeopathic drugs,depending on the starting concentration) corresponds to109 (one billion) molecules per litre, which is also equiva-lent to 106 (one million) molecules per cubic centimetre, or1000 molecule per cubic millimetre. Taking blood as areference substance, it contains around 7000 leukocytesper cubic millimetre, meaning that in this case, a10�15 M solution would contain one molecule for everyseven cells. It is clear that the action of ULDs, whichcontain very low doses of active substances, poses a chal-lenge to pharmacology and claims the existence of ampli-fication mechanisms at some stage of the signaltransmission chain, from molecules in water environmentto signalereceptor interaction and the wide range of trans-duction pathways. A simplified scheme of some amplifica-tion steps at the level of receptors and signal transductioninside the cell is depicted in Figure 1.Receptors for signal molecules or for other types of mes-
sengers (light, EM signals, stretching, action potentials) arehighly plastic: the cells are capable of increasing (hyper-sensitivity, priming) or decreasing (desensitization, toler-ance, adaptation, downregulation) the number ofreceptors according to their needs, as well as of regulatingtheir activity by modifying the affinity for the signal mole-cule. On occasion, the cells may present more than one re-
ceptor for the same molecule, but with different affinitiesand different intracellular effects.The intracellular transduction systems couple receptor
activation with production of signals or activation ofeffector mechanisms; they are associated with enzyme ac-tivities, variations of intracellular second messengers,modifications of membrane lipids and proteins, and theopening of ion channels. Small changes of concentrationand/or of oscillations frequency in second messengerslike free calcium, protons (H+), cyclic adenosine mono-phosphate (AMP) and phospholipid derivatives can induceallosteric modifications of enzyme functions, chain reac-tions and cascades of intracellular signals, and eventuallygene expression. The multiform characteristics of the re-ceptor and transduction systems are too vast to be dealtwith here. What is beyond doubt, however, is that the levelof responsiveness is controlled at various levels in the cell,that the sensitivity to external messages is modified duringthe course of disease, and that all these mechanisms aresusceptible to pharmacological modulation as well as bydiet (e.g., the change of membrane lipid composition, therole of antioxidants, the epigenetic effects of food compo-nents).In summary, a few extracellular molecules or even a sin-
gle molecule, or extremely low magnetic fields can trigger(or regulate) a series of chain reactions that lead to the acti-vation (or downgrading) of the specific cell function relatedto that particular signal. According to this model, interac-tion between a potentized homeopathic solution and thecell surface causes the membrane proteins, or their glyco-sylated parts, to produce a cascade of biochemical eventsinside the cell resulting from contact with the drug itself.Such events could be enormously amplified at the receptorand post-receptor level, to even affect gene expression.18,89
We90,91 and others92e94 have previously illustrated howreceptor sensitization and desensitization, and in generalthe postconditioning of cells by various types oftreatments, may support the beneficial effect of low dose
Figure 2 An intuitive illustration of stochastic resonance in plasma membrane. (A) The glycocalyx introduces a noise as an amplifier of sig-nalereceptor interaction and increases the periodic signal passed to the transduction systems. (B) Upper diagram: A small periodic signal,with energy under the activation threshold of receptor, produces no response. Intermediate diagram: Noise contains no specific informationand the receptor is not activated. Lower diagram: When the noise is added to the signal, the activation energy exceeds the threshold and thesystem receives an information with a frequency component equal to the periodic signal, but stronger than the pure incoming signal.
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stress compounds that are applied according to the similiaprinciple.In the previous paper we cited the findings that silica
nanostructures are formed during succussion in glass con-tainers which are usually employed in the preparation ofhomeopathic drugs.95 Recently Ives et al.96 showed thatboron, silicon, and sodium leaching from glass containersare present at micromolar levels and have enzyme activitystabilizing effects. Moreover, the increased enzyme stabil-ity could be mimicked in a dose-dependent manner by theaddition of silicates to the enzyme assay. This finding sug-gests a further mechanism of amplification of biologic ef-fects of homeopathic drugs.
Stochastic resonance
A further point linked to the ULD effects concerns reso-nance phenomena,97,98 which are involved in bothinformation transfer and signal amplification. Stochasticresonance is a seemingly paradoxical concept, accordingto which background noise (random fluctuations ofenergy and molecular vibrations that disturb any naturalsystem) may increase, rather than decrease, theperception of signals (see Figure 2). So, by this process,a system may become sensitive to stimulations so smallthat they would not otherwise be perceived. In recent years,a series of experiments have shown that this phenomenonoccurs in lasers, superconductors, electronic circuits, neu-rons, and biological membranes.99,100
Stochastic resonance requires a physical system capableof making transitions between two or more states (oscilla-tions), and of being perturbed by an input which can consistof an aperiodic ‘noise’ and of a periodic signal that is weakwith respect to the noise. For example, stochastic reso-nance may involve the membrane glycocalix which mayintroduce a noise as an amplifier of signalereceptor inter-action. When the noise of glycocalix oscillations is addedto a (small) periodic signal, the periodic oscillation isamplified, and at its output the system emits a signal witha frequency component equal to the periodic signal, butstronger than the same incoming signal.The membrane potential is a source of EM noise gener-
ated by continuous vibrations of charges and molecularbonds, and by fluctuations in the dynamics of ion channels.The lipidewater interfaces are transition regions with avery refined electrical structure, and highly sensitive toelectric fields so that even the slightest change in their elec-trical properties has an impact on the structure and the olig-omerization state (aggregation function) of proteins in thesame membrane.101 Thus there is a nonlinear relationshipbetween the incoming signal (input) and the transmittedsignal (output): when the input drops below a giventhreshold value, there is no output at all. On the otherhand, a very weak signal can be elevated above thethreshold when it encounters the right amount of noise,and enters into resonance with it; i.e., the signal encountersa resonance that can amplify it to an appropriate level forthe transmission. Intracellular events such as calcium oscil-lations, are increased by background metabolic noise.102
The role of water
Membrane proteins interact not only with signal mole-cules but also with water molecules and clusters, a phe-nomenon that leads to protein conformational change andtransient proton transfer.103 This leads to the hypothesisthat biological effects of HDs can also be mediated bytransmission of EM energy (and information) through wa-ter, using the ultra-fast and extremely efficient transfer ofenergy, as exemplified in Figure 3.Chains of water molecules facilitate proton transfer
within hydrophobic proteins. Since this occurs at an inter-mediate conformation only, the rearrangement of protein-bound water molecules, from inactive positions in theground state to an active chain in an intermediate state, ap-pears to provide insight into proton-transfer mechanismsand functions of ubiquitous membrane spanning pro-teins.103 The Grotthus mechanism also works in so-called‘water wires’ that enable hopping of protons throughtrans-membrane proteins such as bacteriorhodopsin thatfunction as a proton pump.108
Such ‘supramolecular’ organization of water in chains issimilar to the proton ‘hopping’ mechanism proposed byGrotthus,106 and may account for amplification of effectsof drugmolecules dissolved in water. An indirect confirma-tion that this may account for some activity of HDs is theincrease of electrical conductivity of highly diluted/suc-cussed solutions reported by Elia.107 When an H+ ion en-counters a water molecule in a favourable geometricalposition, it forms a bond with the water molecule whichin its turn releases an H+ ion. Thus, it is effectively as ifions that encounter a water molecule (which enables this‘hop’) diffuse faster than ions which do not meet a watermolecule in this favourable geometrical position. Varia-tions in the supramolecular structure of water may augmentthe contribution of the hopping mechanism and hence theresultant diffusion of ions, thereby also increasing specificconductivity.
Information transferThe transmission of drug information from remedies of
low and medium potency (ULDs) to body target systemscan occur through molecular interactions, regulated by
Figure 3 Schematic representation of ultra-fast inter-molecularenergy transfer in water by excitation of OeH bond. Free adapta-tion of evidence provided by Nitzan and Woutersen.104,105
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affinity and concentration, as in conventional drugs. Com-pounds can interact with local receptors (e.g., in the mouthor on the skin) or be absorbed by mouth or intestine andtransported to their targets through biologic fluids likeblood and lymph. On the other hand, it is conceivablethat HDs can use different pathways of signal transmission,like body water, nerve impulses, solitons, or even EM path-ways. We call these pathways of signal transmission as‘meta-molecular’ since they may require molecular move-ments and changes, but are not restricted to them. Use ofHDs is a tentative approach to the bioenergetic regulationof the human body on a physicalebiochemical interface,made possible by the extreme sensitivity of biological sys-tems to this type of regulation.
Biophysical interactions
There is no single unitary explanation for the action ofHDs on the organism, however an accumulation of evidencefrom various fields of science is building up a conceivableand plausible picture, in which biophysics is integratedwith molecular biology and system biology. If the problemis couched in physical and not merely in chemical terms, itis very likely that any such explanation must necessarilytake into account the sensitivity of living systems to smallenergies like those carried by EM fields.109,110 In thiscontext, the emerging bioelectromagnetic paradigm willhave an important role because it re-evaluates an importantform of long-range communication, not only at inter-molecular but also at supramolecular levels of organizationof biological systems.Cells are able to detect and respond to weak electric and
magnetic fields, possibly through glycoprotein bound toionic channels.111 Several molecular systems have beenshown to be sensitive to EM fields, even of very low inten-sity: photoreceptors (eye and skin), chlorophyll, G-Protein-coupled trans-membrane receptors, cAMP-dependent pro-tein kinase, heat-shock proteins (hsps), chromosomes,Na+/K+ ATPase, lysozyme, membrane ionic channelsand even water itself. Cells are detectors of very weak pe-riodic magnetic fields at around 10�3 V/cm intensity, but inspecific frequency ‘windows’, i.e., where certain responsesoccur only within a restricted frequency band, the mini-mum intensity, necessary to trigger the cell response,may be several orders of magnitude lower (10�6 V/cm).112 On the other hand, in living systems there are anumber of sources of EM fields: electrical activities of ner-vous centres and heart, chargemovements (ions) in vessels,charge movements (ions, H+) inside cells, membrane po-larization/depolarization, electron-transport and proton-transport chains in mitochondria, proton jumping in waterand proteins, oxidationereduction metabolic activities,phosphorylation/dephosphorylation processes, enzymesthat generate chemiluminescence, release of biophotonsby DNA, muscle contraction, piezoelectric activity (onbending) of bone, connective fibres, microtubules, and mi-crofilaments. Althoughmany of these electrical events maybe by-products of metabolic activities without any specificfunction, the widespread EM sensitivity of sensing and
transduction systems suggest that they are also utilized assignalling modes for communication and coordinationamong cells and tissues.Practically all organisms emit light at a rate from few pho-
tons per cell per day to several hundred photons per organ-ism per second. This emission of ‘biophotons’, as they arecalled, is distinct from the chemiluminescence of leukocytesor the bioluminescence of fireflies, which is associated withspecific organelles. Biophotons emission occurs at very lowintensity but is universal to living organisms, where it isthought to represent a long-range form of communication,capable of generating synchronous and coherent phenom-ena.113e115 DNA generates a longitudinal wave thatpropagates in the direction of the magnetic field vector,and frequencies computed from the structure of DNAagree with those of the predicted biophotonic radiation.116
The authors suggest that such a wave is able to use geneticcode chemically stored in the base pairs of the genes andto electrically modulate them, so as to ‘piggyback’ informa-tion from the cell nucleus to another cell. At the receivingend, the reverse process takes place and the transported in-formation is converted back into a chemical structure.It has been suggested that acupuncture meridians are
related to an interconnected cellular network that regulatesgrowth and physiology117 and meridians can, to a certainextent, be compared with pathways for the propagationof electronic excitation in the body, similar to optical wave-guides along which EM pulses propagate as solitons.118
This theory may explain the high electric conductance ofthe meridian system, and electrodermal activity may be avaluable physiological marker for the acupuncture phe-nomenon.119,120
A review of the current progress in understanding coher-ence effects in relation to the mechanisms of homeopathyand acupuncture, and of how bio-information may bestored in water has been published by Smith.121 The authorconcludes that living systems interact with external EMfields in such a way that it should be possible to controlchemical reactions both in vitro and in vivo through theinteraction of the magnetic vector potential with the chem-ical potential. EM fields have a long range and then are ableto produce recognition at a distance, also in a crowd of non-resonating molecules. Long-range EM communication be-tween molecules may represent the founding theory able tounravel the nature of the molecular signal and the role ofperimolecular water in its transmission.122
Electronic transfer of information
There is mounting experimental evidence that biologicalinformation capable of modulating cellular behaviour andresponses can be transferred by electronic means. The re-sults of ‘digital biology’ suggest a previously unknownEM nature for the molecular signal. This signal, that is‘memorized’ and then carried by water, most likely enablesin vivo transmission of the specific molecular informationbetween two functional biomolecules.122
In one study, neutrophils placed on one coil of an oscil-lator were activated by phorbol ester placed on another
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coil, suggesting that molecules emit signals that can betransferred to neutrophils by artificial physical means.123
Intriguing experiments evaluated cell proliferation rateand morphology in two different cell populations seededin separate polystyrene culture dishes incubated one abovethe other: cell activities were different depending onwhether there was a disk of black paper to separate thedifferent dishes, suggesting that specific signals emittedby the cells were transmitted through the polystyrenewall.124 Others reported an electrical transfer phenomenonusing a device made by a glass test tube filled with distilledwater (intended as receiver) and a quartz test tube with asource compound (Amanita muscaria dust, magnesiumsulphate).125 Two solutions were connected by a highvoltage field pulse for 15 min, then the exposure of biolog-ical systems (cress germinating seeds, E. Coli bacteria) tosuch electrically-treated water caused a growth inhibitionof the tested cultures.The notion that organisms have mechanisms for gener-
ating biologically useful electrical signals is not new, butthe modern version is that magnetic fields act in conjunc-tion with ion cyclotron resonance (ICR), to regulate andtransmit biological and pharmacological informationwithin living systems. ICR predicts effects by small ionsinvolved in biological processes, which occur in definitefrequency- and intensity ranges (‘windows’) of simulta-neously impacting magnetic and EM fields.126,127
According to Liboff, changes in human body impedanceare significantly altered during exposure to ICR andsinusoidal magnetic field combinations and proteinpeptide bonds are broken by ICR fields at ultra-low mag-netic intensities (0.05 muT).128 Investigating the phenom-enon of resonant signalling, it has been reported thatexposure of human epithelial cell to ICR, generated by acommercial electromedical device tuned to calcium ionat 7 Hz, acts as a cell differentiation factor.129 Furthermore,it has been observed that specific frequencies modulate cellfunction and therefore can help restore or maintainhealth.130
The phenomenon of ‘digitization’ of biological signalswas reported by Benveniste’s group123 and recently con-firmed,131e135 with the exception of another group.136 Inbrief, Montagnier et al. demonstrated the ability of somebacterial DNA sequences to induce EM waves at HDs inwater. A solenoid captured the magnetic component ofthe waves produced by the DNA solution in a plastictube, converting the signals into an electric current. Thiscurrent was then amplified and finally analysed on a laptopcomputer using specific software. Each dilution was fol-lowed by strong agitation and this step was found to be crit-ical for the generation of signals. Such signals appear to bea ‘resonance phenomenon’ triggered by the ambient EMbackground of very low frequency waves.132 Interestingly,the genomic DNA of most pathogenic bacteria contains se-quences that are able to generate such signals, suggestingthat a highly sensitive detection systemmight be developedfor chronic bacterial infections in human and animal dis-eases. A second paper followed up this suggestion,showing that it is indeed possible to detect the presence
of HIV DNA even when the RNA of the virus has disap-peared from the blood of HIV-infected people undergoingantiviral therapy.133
Recent investigations showed that retinoic acid (aneuronal differentiating agent), placed on one coil attachedto an oscillator, induced a decrease in cell growth, meta-bolic activity, and the protrusion of a neurite-like structurein neuroblastoma cells incubated on another coil connectedthrough an electronic amplifier.134 If confirmed, theseexperimental results provide some evidence that the incu-bation medium could be tuned in a resonant mannerthrough a carrier frequency provided by the oscillator.135
Taken together, these findings suggest that there are associ-ated molecular signals that can be transferred to target cellsby physical means in a fashion that mimics the originalmolecules.
Water, nanoparticles and molecular interactions
The importance of water to living processes derives notonly from its ability to form hydrogen bonds with other wa-ter molecules, but especially from its capacity to interactwith various types of biological molecules. Because of itspolar nature, water readily interacts with other polar andcharged molecules such as acids, salts, sugars, and variousregions of proteins and DNA. Recent advances in theoret-ical methods, experimental techniques and brutecomputing power have made it possible to study how waterinteracts with DNA, proteins and cells in unprecedenteddetail. Protein binding to specific DNA sequences is akey element in various biological functions related to pro-cessing of genetic information by regulating transcription,replication, and recombination. The mechanism of DNAsequence discrimination, however, is still poorly under-stood.Water is an essential participant in macromolecular
binding and can contribute to recognition in severalways. Complex formation is initiated by interactions be-tween partners of proteineprotein or proteineDNA mole-cules with fully hydrated surfaces. During the process,specific bound waters are expelled from the interface, lead-ing to burial of the contact surfaces. However, a number ofwater molecules may remain trapped at the interface andserve to mediate interactions between the macromolecules.Interfacial water molecules in specific complexes not onlyact as linkers, but have also been shown to buffer electro-static repulsion between negatively charged groups of pro-tein and DNA.137
The functioning of enzymes and protein folding is wellknown to be assisted by the surrounding chaperoning watermolecules, which are connected to the proteins via non-covalent, dynamically changing chemical bonds. Waterclusters have a key role in the light receptors of bacteria:on excitation by light, retinal isomerization leads to a rear-rangement of a water cluster that partly disconnects two he-lices of the receptor. This hydrogen bond network proceedsfurther in later stages of conformation transitions, alteringtertiary structure and establishing the signalling state of thereceptor.138
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High-resolution protein ground-state structures of pro-ton pumps and channels have revealed internal protein-bound water molecules. Their possible active involvementin protein function has recently come into focus. An illus-tration of the formation of a protonated protein-bound
water cluster that is actively involved in proton transferwas described for the membrane protein bacteriorho-dopsin.103 The authors showed that three protein-boundwater molecules were rearranged by a protein conforma-tional change that resulted in a transient Grotthus-type pro-ton-transfer chain extending through a hydrophobic proteinregion. This discovery provides insight into proton-transfermechanisms through hydrophobic core regions of ubiqui-tous membrane spanning proteins such as G-proteincoupled receptors or cytochrome C oxidase.The concept of aqueous nanodomains has been intro-
duced to explain high potentization in homeopathy. Simu-lations show that these long-lived nanodomains mayinteract with their targets, such as inactive enzymes, con-verting them into the active form. This simple model omitsmany of the complexities of a live organism but incorpo-rates the essential elements of homeopathic action.139
Nanoparticles have unique biological and physicochemicalproperties, including increased catalytic reactivity, proteinand DNA adsorption, bioavailability, dose-sparing, EM,and quantum effects that are different from those of bulk-form materials.140 Enzyme regulation involves molecularallosteric changes due to interaction with other molecules,phosphorylation/dephosphorylation of specific aminoacids, and complex formation. However, all these eventsoccur in a surrounding non-covalent intracellular network
Figure 4 Scheme of how a water cluster may change a proteinconformation by breaking internal hydrogen bonds.
Figure 5 Hypothetical model of various ways of biological communication. (A) Left side: Classic moleculeereceptor interactions, (B) Centre:Resonance interaction between water nanodomains and cell membrane receptors and/or DNA, (C) Right side: Classic biophysical regula-tion of receptor responses. The water nanodomain is formed by water molecules oscillating in phase, where oxygen is represented by redspheres and hydrogen by blue spheres. For details concerning the physicochemical nature of homeopathic remedies see the previous paper(For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article).1
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made up of water molecules. These water molecules do notjust play a part in solvation, but also function as chaperonecatalysts participating in the regulation of chemicalchanges in living cells. A ‘water-regulated cycle’ consist-ing of this type of intracellular network of weak non-covalent connections may be presumed to exist in livingcells.141 An intuitive sketch of how a water cluster couldalter the conformation of a target protein is shown inFigure 4.
Water and gene expression
DNA recognition by proteins involves a subtle interplaybetween direct proteineDNA interaction and the indirectcontribution from water and ions. The structure and ener-getics of water at the proteineDNA interface show that wa-ter distributions exhibit sequence-dependent variations,suggesting that interfacial waters can serve as a ‘hydrationfingerprint’ of a given DNA sequence.137 The double helixstructure, the strength of the hydrogen bonds, and even theDNAvolume tend to change with increasing water content.The bound water sheath is not just an integral part of suchstructures. It can also perform a precise switching function,because results indicate that increasing the hydration shellby only two water molecules per phosphate group maycause the DNA structure to ‘fold’ instantly.142 High-resolution crystal structures of the DNA duplex sequencereveal a highly-conserved cluster of 11 linked water mole-cules, positioned in the minor groove. This cluster appearsto have a key structural role in stabilizing the non-covalentbinding of small molecules and in mediating between li-gands and DNA by means of an array of hydrogenbonds.143
An interesting view of how coherence domains postu-lated by quantum electrodynamics theory may interactwith biochemical pathways, has been recently proposed.144
When the energy stored in the EM field of a coherencedomain becomes equal to (resonates with) the activationenergy of a specific non-aqueous molecule, the coherencedomain discharges its energy to perform a specific reaction(coupling of EM and chemical modes).
Resonance and drug effects
A further concept linking homeopathy with a biophys-ical perspective is that disease may be regarded not onlyas a functional or molecular-structural abnormality, as inthe classical view, but also (and not by way of contrast)as a disturbance of an entire network of EM communica-tion. Such a network is based on long-range interactionsbetween elements (molecules, nerve centres, organs, tomention but a few) which oscillate at frequencies thatare coherent and specific, and so capable of resonance.The disease processes, besides causing quantitative andqualitative molecular alterations, involve a disturbanceof the bioelectric harmony and coherence of the body,of oscillation frequencies and of the communicationsassociated with them. If this is the case, it should bepossible to bring these alterations back to a state of equi-librium by means of ‘tuning’, i.e., by a change in fre-
quency imposed by resonant interaction with anotheroscillator. According to this notion, the homeopathicremedy might act upon the patient as an external guidingfrequency.On this basis, a hypothetical model of the possible action
mechanism of homeopathic drugs can be advanced (seeFigure 5). A potentized homeopathic drug might be re-garded as a small amount of matter containing elementsoscillating in phase (coherently), which are capable oftransmitting these oscillatory frequencies, via a processof resonance, to biological fluids (in turn mostly made upof water), but also to complex ‘metastable’ structures.These structures (macromolecules, a-helixes, membranes,filamentous structures, receptors) are subject to nonlinearbehaviour patterns and are capable in their turn of oscil-lating. There is thus the possibility of a resonance linkforming between drug frequencies and oscillators presentin the living organism perturbed by disease. The nanopar-ticulate water clusters or CDs would thus not act by ‘con-ventional’ molecular interactions based on mass law, butrather by modulating through resonance interactions the in-ternal EM communications whose energy is provided bythe cell metabolism.145
The EM hypothesis of homeopathic drug action is veryattractive but, at the present state of knowledge, is mainlyspeculative and is awaiting physical or mathematicalformalism. Information transmission phenomena requireresonances between oscillators of close frequencies (even-tually between harmonics). There are many orders ofmagnitude between the frequencies of molecular vibra-tions (>1013 Hz) and, for example, the EM signals emittedby HDs of DNA (1000e3000 Hz).132,133 How can thoserelatively low frequency waves of DNA solutionsmodulate high molecular frequencies responsible forspecific biochemical reactions remains to be clarified,even if some hypothesis has been put forward by theauthors.131
Theinversionofeffects (thesimile)According to the homeopathic law of similia, the remedy
able to positively regulate a diseased organism (personal-ised homeopathic treatment) is the same substance thatelicits similar symptoms in a healthy organism. The ho-meopathic pharmacopoeia was developed through carefultesting of hundreds of substances on healthy people todetect their specific and global perturbation power. Thiswas the first systematic application of pharmacologicalexperimentation in the history of medicine, and it con-tinues to this day.The various theories of the simile have been described in
previous papers.90,91,146,147 The characteristic ‘therapeuticsimilarity’ in drug action purported by homeopathy may befundamentally based on the widespread phenomenon ofinversion of biological effects dependent on thefollowing factors: (a) the dose utilized and absorbed, (b)the time or schedule of administration, (c) thephysiological state of the receiver/target system. Acombination of one or more of these factors and the
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contribution of complexity science give rise to a consistenttheory of the homeopathic ‘simile’ effect.91,147
Hormesis
Currently, efficacy is intuitively regarded as being higherwhen more molecules of drug reach the target (receptor,enzyme), but this approximation is largely incorrectbecause doseeresponse curves are often nonlinear andeven paradoxical. There is a widespread occurrence oflow molecular dose effects that appear to be opposite tothose caused by high molecular doses, as seen in hormesis.Moreover, in vivo acute and chronic effects of drugs areoften opposite in their effects, an observation that some au-thors have suggested could be exploited using conventionaldrugs148e150 or homeopathic remedies.151
Various authors have suggested that hormetic phenom-ena can provide a framework for interpreting homeopathiceffects, at least insofar as low dilutions, rather than HDs,are concerned.91,152e157 Inverse (or ‘paradoxical’) effectsof drugs or of biologically active compounds on specifictarget systems can be often observed by changing theconcentrations or the doses of the compound: forexample, low doses of a toxic compound may bestimulatory, high doses may be inhibitory (as we will seelater, also the opposite may be possible, according to theexperimental systems employed). In general theseeffects, formerly described in the ‘ArndteSchulzLaw’,158,159,160 can be documented by the finding ofinverted U-shaped curve of doseeresponse. Endpointsdisplaying this curve include growth, fecundity, andlongevity. Another possibility is to find a time-course ofan intoxication experiment where high dose causes pro-gressive death of biological system, while a low dosecauses an initial decrease of viability, followed by a recov-ery (rebound) and an increase over the basal levels.Despite the substantial development and publication of
highly reproducible toxicological data, the concept of hor-metic doseeresponse relationships was not integrated intothe mainstream of toxicological thought until recentyears.161 This phenomenon is now well recognized, with
a number of explanation at the molecular level (e.g.,different receptors for the same substance having differentligand affinities and triggering transduction pathways) andin immunology, where the systemic and local responses areknown to depend on the dose in a complex way (e.g.,foreign antigens may sensitize the host but low doses ofthe same substance may suppress the system if adminis-tered by oral route). The term ‘postconditioning hormesis’was introduced to indicate the phenomenon where smallstimuli exert a beneficial effect when applied to cells or or-ganisms which previously experienced a severe harmfulstress.162 As an example, a low level of hypoxic stresswas applied subsequent to myocardial infarction, whichreduced the cellular damage.Tables 2 and 3 summarize several examples of inverse
effects according to the dose in laboratory systems and inanimal models respectively.Without going into many details, the paradox of arsenic
can be mentioned as an example. This mineral is a well-documented carcinogen that also appears to be a valuabletherapeutic tool in cancer treatment.216 In this context,the research line of the group of Van Wijk et al. is worthyof citation.93,152,152,217 In response to proteotoxicity, cellsreact with an upregulation of hsps. These proteinsfunction primarily as molecular chaperones, facilitatingthe folding of other cellular proteins. When cells weredamaged with chemical compounds such as arsenic orcadmium and subsequently exposed to low doseconditions of the same compounds, both hsps synthesisas well as defence and survival capacity were enhanced(‘homologous’ simile). Low doses of arsenic were alsoable to enhance survival of cells to a heat shock(exposure to temperatures >42.5�C) (‘heterologous’simile). This line of research clearly demonstrates thebiphasic action of a substance: a small dose can exert astimulatory effect on the recovery and the developmentof survival capacity of cells that have been previouslydisturbed by a high dose of the same substance. It is ofinterest that this stimulatory effect of low dose stress isdependent on the initial exposure condition: the moresevere the initial stress conditions, the smaller the
Table 2 Examples of inverse effects in laboratory systems
System Agent First effect Inverse effect
Yeast163 Heavy metals Block growth Low doses increase growthLeukocytes164 Cytostatic agents Cytotoxicity Low doses stimulate growth and phagocytosisFibroblasts165e167 Arsenite
CadmiumCell toxicity Low doses protect from toxicity or stimulate
DNA synthesisNeurons168,169 Naloxone Antagonizes morphine Low doses enhance the effect of morphineEpithelial cellsTumor cells170
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concentration required for stimulating survival and hspsinduction.Our group has given several contributions in this field,
like the demonstrations that bacterial peptides (leukocytereceptor agonists with powerful stimulating activity onleukocyte metabolism and adhesiveness) have inhibitoryeffects on leukocyte adhesion when used at lowdoses.172,218 This paradoxical effect of low-dose peptidesis probably due to the ‘gating’ exerted by cAMP at the levelof intracellular signal transduction pathways.146,219
Furthermore, we showed that human platelets areinhibited by low doses and stimulated by high doses ofnon-steroidal anti-inflammatory drugs148,171 and thatpodophyllotoxin inhibits leukocyte metabolism whenadministered at high doses while it exerts a stimulatingrole (priming) at low doses.173 These observations are inthe framework of the hormesis concept.Although the inversion of effects is often observed on
changing the doses (or dilution/dynamization steps in ho-meopathic terms), this is not a general rule. Others have re-ported that Ruta, Thuja, Hydrastis and Carcinosinum havecytotoxic and apoptosis-inducing effects on several cellcultures, even at homeopathic doses.220,221 In animalmodels, Silica (which is a stimulant of macrophages andfibrous tissue formation at high doses) stimulates tissuehealing and macrophage activation also at extremely low(homeopathic) doses.33,34 We have observed181 that quer-cetin, a natural compound contained in fruits and vegeta-bles, exhibits a ‘inverted U-shaped’ doseeresponse curve(stimulation at low doses, inhibition at high doses) whenhuman basophils are stimulated by bacterial peptides.
However, when the cells are stimulated by anti-IgE anti-bodies (mimicking an allergic reaction) the inhibition ex-erted by quercetin is observed both at low and at highdoses, the effects being proportional to the dose utilized.Regarding the effects in animal models, the studies from
the group of Doutremepuich deserve citation. Starting fromthe observation that platelet aggregation on whole bloodwas stimulated after administration of ultra-low dosageacetylsalicylic acid in healthy volunteers,222 they exten-sively investigated these effects in a rat model of thrombusformation.184e186 A partial occlusion was induced in smallmesenteric vessels by an argon laser. The laser induceddamage of endothelial cells and thrombi formed withinseconds after the laser lesion and grew rapidly.Embolization began during the minute following thelaser injury. Compared to placebo, the administration ofacetylsalicylic acid at ULDs induced an increase innumber of emboli and in the duration of embolization.These findings are highly paradoxical because the‘conventional’ pharmacological effect of acetylsalicylicacid would be to inhibit platelet aggregation andthrombus formation. Also paradoxical pro-inflammatory,pro-thrombotic effects associated with chronic use ofanti-inflammatory agents have been described.223 Theseeffects are attributable to compensatory host responserather than direct effects of the drugs.At Verona University we explored the applications of
similia principle in various animal models. The first oneshowed that HDs of histamine are able of modulating theinflammation caused by high doses of histamine inrats.198 A second rat model was developed by our group,
Table 3 Examples of inverse effects in animal models
Rat214 Bacillus antracis Severe inflammation anddeath
Low doses of bacillus extract protectfrom toxicity
Mice215 Gelsemium sempervirens Causes severe weakness,dizziness, convulsions
HDs are anxiolytic and increase explorationmovement
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showing that injection of low doses of immune adjuvant(based on killed Mycobacterium butyricum, Mb) into theperitoneum of rats is capable of preventing and curingthe arthritis induced by the injection of high doses of thesame adjuvant into the paw.205 Local injection of low dosesof Mb at 3rd and 10th day after adjuvant arthritis inductionis correlated with suppression of primary and secondary le-sions of disease, decrease of inflammatory cytokines likeIL-6, increase of anti-Mb antibodies, increase of nitrite/ni-trate serum levels and growth of regulatory peritonealcells.206 This kind of immunoregulation by the ‘simile’(‘isopathic’ approach according to the traditional terminol-ogy) is coherent with several other lines of evidence ob-tained in animals and in humans.91,160,191
Others have questioned whether there is a direct link be-tween homeopathy and hormesis, arguing that homeopathyis a highly individualized therapeutic system, that homeo-pathic concentrations are often far below the Avogadronumber and that hormetic substances do not require anyspecial preparation.224 The relationship between hormesisand homeopathy has been recently discussed in a full issueof Human and Experimental Toxicology. As we90,91 andothers156 have pointed out, hormesis is the name given toexperimental evidence of certain apparently paradoxicalphenomena, but does not itself constitute any sort ofexplanatory theory, least of all for homeopathy. Eachexample of a hormetic curve can be explained by one ormore mechanisms, which are today being explored withever greater detail and thoroughness: transduction of extra-cellular signals into intracellular messages, cellular and tis-sue repair systems, control of cell growth and apoptosis,genetic and epigenetic molecular changes. In any case,the traditional hormesis concept applies only to molecular‘doses’, that is to concentrations from zero (no effect, takenas a control) upward; homeopathy also employs very HDs/dynamizations that in theory do not contain a single mole-cule of the original active substance.
Paradoxical pharmacology and rebound effects
Inverse (or ‘paradoxical’) effects of drugs or of biologi-cally active compounds on specific target systems can beoften observed by changing the time or duration of the appli-cation of the treatment and the observation period. Forexample, short treatment may be stimulatory, long lastingapplication may be inhibitory (also the opposite may bepossible, according to the experimental systems employed).This field includes rebound effects (reversal on withdrawal)and paradoxical pharmacology. One possible general hy-pothesis for why paradoxical pharmacology might work isthe difference between the chronic versus the acute effectof drugs.91,149,150 It has been suggested151,225,226 that evenmodern drugs can be utilized according to the principle ofhomeopathic cure, employing the rebound effect as acurative reaction. It would be possible to compile aMateria Medica that would group the symptoms producedby rebound effects of the medications in humanindividuals, utilizing them, a posteriori, following a partialor total similitude, in minimal or ponderous doses. By
doing that, it should be possible to take advantage of themodern pharmacological experimentations either inhealthy individuals (phase 1 trials) or in ill people (phase2e3 trials), thus amplifying the spectrum of homeopathiccure with a wide range of new symptoms and medications.Finally, inverse effects of drugs, or of biologically active
compounds, on specific target systems can be oftenobserved by changing the physiological state or the suscep-tibility conditions of the system itself: for example, thesame compound may cause stimulatory, growth-promoting effects on a healthy/unperturbed system andinhibitory, suppressing effects of the same variable whenapplied to the diseased/previously perturbed system (alsothe opposite may be possible, according to the experi-mental systems employed). This field includes the “initialvalue rule of Wilder”227,228 and other widely documentedpharmacological phenomena.91
In summary, the applications of the ‘simile’ principle einterpreted as inversion of biological and pharmacologicaleffects of active compounds according to the dose and/orthe sensitivity of the target system e are widespread andconsistent: stimulation or protection by low doses of toxiccompounds (typical hormesis effect) on cell and animalmodels, regulation of specific cellular activities by lowdoses of stimulating compounds, inhibition or protectionof autoimmunity by low doses of antigen, and paradoxicaleffects of drugs. Within the framework of our currentknowledge of living systems and modern investigationaltechniques, it will be possible to reformulate the ancientprinciple with the aim of constructing reasonable modelsthat can be tested at different biological levels, from cellsto human beings.
Systems biology
In dynamic systems far from thermal equilibrium, min-imal variations in the internal or ambient conditions (suchas those induced by even a very small oscillatory reso-nance) may play a decisive part in the ensuing evolutionof the system itself. In a variety of systems, the ‘butterflyeffect’229 may be used to control chaos, on condition thatthe parameters to be controlled and changed are wellknown.230e233 Systems at any level (e.g., physical,biological, social, ecological) are open to information,energy, and matter to varying degrees, and thereforeinteract with other systems to varying degrees.234 The dy-namic interaction of systems in mutual recurrent feedbackrelationships naturally create resonance and synchroniza-tions, such as those between heart and brain.235 Those in-teractions over time create memory in homeodynamicsystems. The logic of recurrent feedback loops, which ap-plies to all dynamical network systems, leaded to the sys-temic memory hypothesis, applied to high-dilutiontherapies.98
Based on microarray data, it has been suggested thatgene regulatory networks may be regarded as dynamically‘critical’ systems poised near the phase transition betweenorder and chaos,233,236 where extreme sensitivity to initialconditions and small perturbations is well known to occur.
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Genetic regulatory networks may be the target of HDsmessage by virtue of their flexibility in response toenvironmental stimuli.236 According to this argument, thehighly diluted drug might be regarded as a complex solu-tion endowed with nanoparticulate structures capable ofcommunicating some pharmacological information,through a resonance process, to biological fluids and to crit-ical cell systems such as macromolecules, alpha-helixes,filamentous structures, receptors, and DNA networks.This effect could be mediated by the participation of a dy-namic intracellular water network which may be presumedto exist in living cells.141 Chaotic regimes have been foundin a number of physiological systems, including heart andneural systems,237e240 and this would result in enhancedsusceptibility to extremely low energy inputs and tosmall changes of regulatory factors. The mechanismsuggested above is in line with findings that homeopathiceffects in humans can be detected through sensitiveevaluation of heart rate variability.76,241
The working hypothesis is that the homeopathic remedy,containing small amounts of the original substance e or itsinformation imprinted in the solution by dilution and suc-cussion e possesses a high ‘information content’ targetedfor a specific case, by virtue of the similarity between thepatient’s symptoms and those ascribed to the remedy(law of similarity). This information content, acting on asystem in critically sensitive conditions, is able to guideit toward a particular behaviour, somewhat like a ‘catalyzerof order’ or a ‘pacemaker’ that moves the system awayfrom a pathological attractor and redirects it toward a phys-iological attractor.In short, the remedy selected based on homeopathic
principles can be perceived by the various regulation sys-temsdwhich have a crucial role in the dynamics of thepathologydas an exogenous signal that affects particularlyactive receptors, enzymes or genetic networks. The ‘simi-larity’ enables drug information to interact with endoge-nous targets that have lost their regulatory capacity dueto homeodynamic blockages (pathological adaptations)and changes of attractors (miasms).242e244 Preciselybecause it ‘touches’ extremely sensitive points(bifurcations), the target signal, even with minimalenergy, can trigger a homeodynamic reaction that shiftsthe global imbalance of the sick person toward a newdynamic attractor, closer to the state of health.The specificity of the information can be ascribed to
sensitizing (priming) of the receptor system as a result ofantecedent biological stress, to the fact that using low dosesor HDs only touches certain particular systems, and finallyto the complexity of corrective actions at various levels. Inacute diseases, homeopathic regulation can be considered a‘regulation’ in the sense that it abates the counterproduc-tive excesses of the reactions themselves, while in chronicdisease it can be regarded as ‘unblocking’ pathological ad-aptations and redirecting the organism toward correct re-sponses. Others have suggested that refocusing attentionon the dynamics of the patient as a nonlinear complex sys-tem could help account for similar effects of various formsof natural medicine in the healing process of the person as a
unified whole.245e248 Updating the designation from‘homeopathy’ to ‘system regulation therapy’ would mostadequately reflect the integration of this historical butcontroversial medical system with modern scientifictheories and findings.
ConclusionsThe rational view of the pharmacodynamic activity of
homeopathic drugs can thus be set forth as follows:
1. Natural diseases are a consequence of perturbations ofmolecular and bioelectrodynamic networks at thevarious levels of biological organization; the healing orprogression of a disease depends on the systemic and dy-namic rules of the affected networks, which determinethe reactions and/or adaptation to those perturbations.
2. ULDs and HDs of drugs may act on the information net-works of the body, where EM interactions and waterclusters associated with proteins and DNA have a majorrole in the coordination pathways for biochemical reac-tions, neuroimmunological control of body identity andintegrity, and even of psychological integrity.
3. A number of molecular, cellular and systemic targets ofhomeopathic drugs have been described in laboratorymodel systems. These targets are highly sensitive todrug regulation thanks to powerful amplification mech-anisms and to the participation of solvent (water) dy-namics in information transfer.
4. The medicine that has been chosen according to the sim-ilia principle may be perceived by specific regulatorysystems e that have a crucial role in the dynamic ofthe diseasese as specific signal which may trigger a ho-meodynamic reaction that shifts the global disequilib-rium of the ill person toward a new dynamicalbehaviour, proximal to the healthy state.
5. The more sensitive a system is to a particular regulation,the lower should be the dose (or the energy) required toregulate it in an effective way. Frequency informationcan be imprinted into a water solution by succussion,in the form of coherent domains or nanoparticles. Thisis what creates a homeopathic HD solution or potency.
Conflictof interestThe authors declare that they have no conflict of interest.
AcknowledgementsThis work was supported by a grant from Boiron Labo-
ratoires to Verona University and from Italian Ministry ofResearch.
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