Protective effects of potato extracts and 16,16-dimethyl prostaglandin E₂ on the induction of hepatic foci by cotreatment of gamma radiation and diethylnitrosamine

We investigated the effect of potato extracts and 16,16-dimethyl prostaglandin E₂ (DiPGE₂) on the induction of glutathione S-transferase P-positive (GST-P+) altered hepatic foci in newborn Sprague-Dawley rats given single treatment with ⁶⁰Co gamma irradiation and diethylnitrosamine (DEN) alone or in sequential combination. Intraperitoneal injection of 0.15 μmol/g body weight of DEN 1 hour after gamma radiation significantly increased the frequencies of GST-P⁺ hepatic foci compared to DEN or gamma radiation alone and DEN injection 1 hour before irradiation (p < 0.001). Potato extract was given at a dose of 2 mg/ml in drinking water for 3 weeks and DiPGE₂ given at a dose of 10 μg/mouse 30 minutes before irradiation. Potato extracts and DiPGE₂ decreased significantly the number (p < 0.001), area (p < 0.001) and Dmax (p < 0.05) of GST-P⁺ hepatic foci compared to the corresponding control. These results suggest that potato extracts and DiPGE₂ have radio-protective potential and further studies for underlying mechanisms will be necessary.