ANTIOXIDANT POTENTIAL OF THREE MEDICINAL PLANTS: SIDA RETUSA Linn., URENA LOBATA Linn. AND TRIUMFETTA RHOMBOIDEA Jacq. 6.1. Introduction Reactive oxygen species (ROS) such as superoxide (O;), hydroxyl radicals(0H ) and hydrogen peroxide (H2O2-) are considered to be important factors in the etiology of several pathological conditions such as cardiovascular diseases, diabetes. inflammation, cancer (Hemnani & Parihar, 1998; Halliwell & Gutteridge, 1985). aging and neurodegenerative diseases (Beal, 1995; Thomas & Kalyanaraman, 1997). ROS are degraded to non- reactive forms by enzymatic and non- enzymatic antioxidant defense mechanisms. Free radicals react with almost every known biological molecule in their vicinity and damage protein, cause break down of DNA strands and initiate peroxidation of various molecules. The hydroxyl radical is most reactive of all and may be considered the ultimate damaging species whenever superoxide is formed. ROS are implicated in carcinogenesis induced mutation and tumor
25
Embed
SIDA RETUSA Linn., URENA LOBATA Linn. TRIUMFETTA ...ietd.inflibnet.ac.in/bitstream/10603/357/17/17_biological properties.pdfANTIOXIDANT POTENTIAL OF THREE MEDICINAL PLANTS: SIDA RETUSA
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
ANTIOXIDANT POTENTIAL OF THREE MEDICINAL PLANTS:
SIDA RETUSA Linn., URENA LOBATA Linn. AND
TRIUMFETTA RHOMBOIDEA Jacq.
6.1. Introduction
Reactive oxygen species (ROS) such as superoxide (O;), hydroxyl
radicals(0H ) and hydrogen peroxide (H2O2-) are considered to be important
factors in the etiology of several pathological conditions such as cardiovascular
diseases, diabetes. inflammation, cancer (Hemnani & Parihar, 1998; Halliwell &
Gutteridge, 1985). aging and neurodegenerative diseases (Beal, 1995; Thomas &
Kalyanaraman, 1997). ROS are degraded to non- reactive forms by enzymatic and
non- enzymatic antioxidant defense mechanisms.
Free radicals react with almost every known biological molecule in their
vicinity and damage protein, cause break down of DNA strands and initiate
peroxidation of various molecules. The hydroxyl radical is most reactive of all
and may be considered the ultimate damaging species whenever superoxide is
formed. ROS are implicated in carcinogenesis induced mutation and tumor
promotion. Antioxidants act as a masor defense against radical - mediated toxicity
by protecting the damages caused by free radicals. Inhibition of free radical
generation can serve as a facile system for identifying cancer preventive agents
(Troll et al.. 1994)
The traditional Indian medicine and the use of plant drugs against various
diseases receive considerable attention nowadays. Antioxidative components of
natural origin have attracted special interest because they can protect the human
body from free radicals (Osawa et a / , 1990) which are likely to be involved in the
pathophysiology of many diseases such as cancer (Babu et al., 2001). Many
antioxidative components of plant origin have protective activity against cancer
(Anto et a l . 1995). Free radical intermediates such as superoxide anion and
hydroxyl radicals are produced in living systems by various sources such as
ionization of water, X- rays and inflammatory phagocytes. These activated
oxygen species induce DNA strand breaks and chromosomal aberrations in
mammalian cells (C'erutii, 199 1).
It has been reported that the 'rasayanas' are rejuvenators and nutritional
supplements and possess strong antioxidant activity (Sharma et al., 1992). It has
been re-emphasized by the report of Scartezzini & Speroni (2000). A vast number
of literatures documenting the in vitro antioxidant property of polyphenol are
available. Polyphenol acts both as primary as well as secondary antioxidant, by
sequestration of metallic ion and by scavenging active oxygen species
(Morel et al., 1994). Flavones and isoflavones are hormones like phenolic
phytoestrogens of' dietary origin which influence intracellular enzymes, protein
synthesis, growth factor action. malignant cell proliferation, angiogenesis and
possessing major role as cancer protective compounds through several
mechanisms such as antioxidant effect (Formica & Regelson, 1995; Keli et aL,
1996; Meishiang et a l . 1997).
In order to contribute further to the knowledge of Indian traditional plants,
in the present study three medicinal plants were screened to determine their
antioxidant activity in vitro. Sida retusa Lhn. belonging to the family Malvaceae
is known a Kurumthotti in Malayalam and Bala in Sanskrit. The useful parts are
root system, aerial parts and seed. Of these the root system mainly used in
Ayurvedic formulations like Kshirabala prescribed for the treatment of
rheumatism. Acording to Shastri (1968) S. retusa is one of the ingredient of
famous Ayurvedic formulations such as Aravinda Asava, Bala Arishta. Kumary
Asava, Amrita Pvasha Ghrita, Agastya Rasayana and Chavana Prasha Lehya.
The plant is used in the treatment of tuberculosis, rheumatism and in combination
with other drugs and as an antidote to snake venom. Leaves and roots are useful in
urinary complaints. fever. heart disease. burning sensation, piles and all kind of
inflammation. Root is also used in treatment of leucorrhoea and rheumatism
( Nadkami, 1976; Krthikar & Basu, 1981).
Urena lohara Linn. is considered as a substitute of S. retusa, belonging to
the Malvaceae fsmily is known as Uram in Malayalam and Vanabenda in
Sanskrit. The root system of this plant is used as an external application for
lumbago and rheumatism (Nadkami. 1976). Triumfetta rhomboidea Jacq. is
considered as an adulterant of S. retusa is coming under the family Teliaceae.
Fruit, flowers and leaves are used in medicine. Bark and fresh leaves are used for
diarrhoea. Flowers rubbed with sugar and water are given in gonorrhoea to stop
the burning caused by urine (Nadkami. 1976).
Lipid peroxidation was measured by the method of Ohkawa et al. (1979)
by measuring the colour of thiobarbituric acid reactive substance (TBARS)
formed at the end of the reaction. Hydroxyl radical scavenging activity was
measured by studying the competition between deoxyribose and the test
compound by the method adopted by Elizabeth & Rao (1990). Superoxide radical
scavenging activity was determined by the NBT reduction method of Mc Cord &
Fridovich (1 969).
6.2.1. Review of literature
Sida species are indiscriminately used for the treatment as antituberculosis,
stomachics, nervous, urinary and cardiac diseases (Chopra et a/., 1958 &
Attygalle, 197 1 ) S. acuta Burm.f. and S. rhomboidea Roxb. are cultivated for the
production of fiber as a substihlte for jute. Extract of S. retusa showed sedative
effect as it decreased alertness, wakefulness and reactivity in mice (Thanam &
Kumari, 197 1 ) It has antirheumatic and antipyretic properties (Iyer & Kolammal,
1993). The various kinds of biological activities viz. antimicrobial and depression
of blood pressure in cats and dogs (Chopra, 1930), immunostimulant (Ghosal
et a[., 1988) antitumour. anti HIV, hepatoprotective and may serve for