ABSTRACT
The effects of aqueous (PnAq) and alcoholic (PnAl) extract (50-250 mg/kg) of P. niruri on in vivo gamma radiation induced chromosome aberration and in vitro antioxidant activity (50-500 µg/ml) were studied. The antioxidant activity was studied by measuring inhibition of hydroxyl radicals generated by the fenton reaction along with pro-oxidant and iron chelating ability. PnAl showed highly significant in vitro free radical scavenging ability when compared to DMSO above 250 µg/ml concentration. PnAq showed significant pro-oxidant activity while PnAl was devoid of it at the tested concentrations. Exposure to gamma radiation (4 Gy) caused 29.10 % increase in the frequency of chromosomal aberrations. Administration of PnAl (250 mg/kg) showed highly significant decrease in chromosomal aberrations compared to radiation treated group. Radioprotective potential of alcoholic extract was found to be more effective than the aqueous extract. Qualitative phytochemical investigation of PnAq and PnAl revealed the presence of sugars, flavonoids, alkaloid, lignans, polyphenols, tannins, coumarins and saponins. Higher radioprotective effect of the alcoholic extract may be attributed to rich presence of antioxidant polyphenolic compounds.