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 withregard to N-methyl N’-nitro-N-nitrosoguanidine (MNNG) induced stomach cancer in Wistar rats. Administration ofthe 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. Forexample, γ-glutamyl transpeptidase activity was decreased from 20.3 ± 6.7 mmol/min/mg protein to almost normallevels (2.8 ± 0.9) by 750mg/kg body weight of the extract. Similarly glutathione S-transferase activity (1317.6 ± 211 nmol/min/mg protein) and glutathione reductase (368 ± 66) levels in the MNNG treated group were found to belowered 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 byMNNG treatment, became near to normal in P. amarus treated animals.