curcumin and methyl(acetoxymethyl)nitrosamine

Catechin and dietary turmeric (Curcuma longa) were used as chemopreventive agents in benzo[a]pyrene induced forestomach tumors in Swiss mice and methyl-(acetoxymethyl)-nitrosamine induced oral mucosal tumors in Syrian golden hamsters. Catechin in drinking water and dietary turmeric significantly inhibited the tumor burden and tumor incidence in both tumor models. The induction of oral tumors in golden hamsters was delayed by catechin and dietary turmeric. Adjuvant chemoprevention utilising both catechin and dietary turmeric inhibited both the gross tumor yield and burden more effectively than when compared to individual components in both tumor models. A single i.p. injection of catechin to male Swiss mice induced increased forestomach and hepatic glutathione S-transferase (GST) activity when compared to controls. These findings suggest that catechin and turmeric which are regularly consumed natural products, are effective in mice or golden hamsters as chemopreventive agents.

Topics: Adjuvants, Pharmaceutic; Animals; Anticarcinogenic Agents; Benzo(a)pyrene; Catechin; Cricetinae; Curcumin; Diet; Dimethylnitrosamine; Female; Glutathione Transferase; Liver; Male; Mesocricetus; Mice; Mouth Neoplasms; Neoplasms, Experimental; Stomach Neoplasms

The inhibitory effect of oral administration of betel-leaf extract (BLE) and 2 of its constituents, beta-carotene and alpha-tocopherol, as single agents or in combination with dietary turmeric on methyl(acetoxymethyl)nitrosamine (DMN-OAC)-induced oral carcinogenesis in Syrian hamsters was studied. DMN-OAC was administered twice monthly for 6 months. The chemopreventive effect of BLE or its constituents with turmeric was determined by comparing tumor incidence observed in treated groups with that seen in control animals. The apparent site-specific chemopreventive effect of BLE or its constituents was demonstrated by inhibition of tumor incidence, reduction of tumor burden, extension of the tumor latency period and regression of established, frank tumors. The inhibitory effect of BLE or its constituents combined with turmeric was higher than that of the individual constituents. The study suggests that BLE could be developed as a potential chemopreventive agent for human oral cancer.

Topics: Animals; Areca; beta Carotene; Carcinogens; Carotenoids; Cricetinae; Curcuma; Dimethylnitrosamine; Drug Screening Assays, Antitumor; Drug Therapy, Combination; Female; Mesocricetus; Mouth Neoplasms; Plant Extracts; Plants, Medicinal; Vitamin E