Influence of Podophyllum hexandrum on endogenous antioxidant defence system in mice: possible role in radioprotection

Podophyllum hexandrum, a Himalayan herb with known radioprotective and anti -tumour properties, was investigated for its mechanism of action. Glutathio ne S-transferase (GST), catalase, superoxide dismutase (SOD) activities and lipid peroxidation (LPx) were determined in the liver, jejunum and ileum a t various time intervals, with and without the aqueous extract of P. hexand rum rhizome (200 mg/kg b.w. i.p.) in unirradiated and whole body irradiated (10 Gy,-2 h) male Swiss albino mice. Pre-irradiation treatment with P. hex andrum enhanced liver GST (P < 0.01) and SOD (P < 0.05) at 12 h post irradi ation, the intestinal SOD (P < 0.00005) at 84 h post irradiation was signif icantly elevated. However, no significant change was manifested in the cata lase activity in the liver, at any of the post irradiation intervals (0, 12 and 84 h). The antioxidant defence with Podophyllum sp. treatment in mice can explain to some extent its protective action manifested in terms of sur vival against whole body lethal irradiation. However, some other possible m echanisms that may strengthen radioprotective action of the Podophyllum sp. extract need to be investigated further. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.