Jp. Kamat et al., Antioxidant properties of Asparagus racemosus against damage induced by gamma-radiation in rat liver mitochondria, J ETHNOPHAR, 71(3), 2000, pp. 425-435
The possible antioxidant effects of crude extract and a purified aqueous fr
action of Asparagus racemosus against membrane damage induced by the free r
adicals generated during gamma-radiation were examined in rat liver mitocho
ndria. gamma-Radiation, in the dose range of 75-900 Gy, induced lipid pel o
xidation as assessed by the formation of thiobarbituric acid reactive subst
ances (TBARS) and lipid hydroperoxides (LOOH). Using an effective dose of 4
50 Gy, antioxidant effects of A. racemosus extract were studied against oxi
dative damage in tel-ms of protection against lipid peroxidation, protein o
xidation, depletion of protein thiols and the levels of the antioxidant enz
yme, superoxide dismutase. An active fraction consisting of polysaccharides
(termed as P3) was effective even at a low concentration of 10 mu g/ml. Bo
th the crude extract as well as the P3 fraction significantly inhibited lip
id peroxidation and protein oxidation. The antioxidant effect of P3 fractio
n was more pronounced against lipid peroxidation. as assessed by TEARS form
ation, while that of the crude extract was more effective in inhibiting pro
tein oxidation. Both the crude extract and P3 fi action also partly protect
s against radiation-induced loss of protein thiols and inactivation of supe
roxide dismutase. The inhibitory effects of these active principles, at the
concentration of 10 mu g/ml, are comparable to that of the established ant
ioxidants glutathione and ascorbic acid. Hence our results indicate that ex
tracts fi om A. racemosus have potent antioxidant properties in vitro in mi
tochondrial membranes of rat liver. (C) 2000 Elsevier Science Ireland Ltd.
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