Inhibition of N-Methyl N'-nitro-N-nitrosoguanidine (MNNG) induced gastric carcinogenesis by Phyllanthus amarus extract.

Chemopreventive activity of Phyllanthus amarus Schum & Thonn (Euphorbiaceae) extract was studied with regard to N-methyl N'-nitro-N-nitrosoguanidine (MNNG) induced stomach cancer in Wistar rats. Administration of the extract with MNNG significantly reduced the incidence of gastric neoplasms in rats (44%) as well as their numbers. Moreover, elevated levels of enzymes in the stomach were found to be reduced by P. amarus administration. For example, gamma-glutamyl transpeptidase activity was decreased from 20.3 +/- 6.7 mmol/min/mg protein to almost normal levels (2.8 +/- 0.9) by 750 mg/kg body weight of the extract. Similarly glutathione S-transferase activity (1317.6 +/- 211 n mol/min/mg protein) and glutathione reductase (368 +/- 66) levels in the MNNG treated group were found to be lowered to 494.8 +/- 76 and 192 +/- 45, respectively, while reduced glutathione (GSH) was increased from 4.6+/- 0.9 to 8.5+/-1.4 n mol/min/mg protein. AgNOR dots and clusters, indicators of cellular proliferation, which were increased by MNNG treatment, became near to normal in P. amarus treated animals.

Hypoglycemic effect of methanol extract of Phyllanthus amarus Schum & Thonn on alloxan induced diabetes mellitus in rats and its relation with antioxidant potential.

Methanolic extract of P. amarus was found to have potential anti-oxidant activity as it could inhibit lipid peroxidation, and scavenge hydroxyl and superoxide radicals in vitro. The amount required for 50% inhibition of lipid peroxide formation was 104 microg/ml and the concentrations needed to scavenge hydroxyl and superoxide radicals were 117 and 19 microg/ml respectively. The extract was found to reduce the blood sugar in alloxan diabetic rats at 4th hr by 6% at a dose level of 200 mg/kg body wt and 18.7% at a concentration of 1000 mg/kg body wt. Continued administration of the extract for 15 days produced significant (P < 0.001) reduction in blood sugar. On 18th day after alloxan administration values were almost similar to normal in the group taking 1000 mg/kg body wt.