Chemopreventive potential of garlic and neem during gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine

We have investigated the modifying effects of garlic (Allium sativum Linn) and neem (Azadirachta indica A. Juss) during pre-initiation and post-initiation phases of gastric carcinogenesis induced in male Wistar rats by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Administration of extracts of garlic and neem inhibited MNNG-induced gastric tumourigenesis as revealed by the reduced incidence of neoplasms. Lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione S-transferase (GST) and gamma-glutamyltranspeptidase (GGT) were used to biomonitor the chemopreventive potential of garlic and neem. Lipid peroxidation was significantly lower, whereas GSH, GPx, GST and GGT activities were markedly elevated, in the gastric mucosa of tumour bearing animals. Our data suggests that garlic and neem may erect their inhibitory effects in the gastric mucosa by modulation of lipid peroxidation, antioxidants and detoxification systems.