Inhibition of nitrosodiethylamine-induced hepatocarcinogenesis by dietary turmeric in rats.
Turmeric, widely used in food and medicine has been shown to prevent benzo(a)pyrene [B(a)P] or dimethylbenz(a)anthracene (DMBA)-induced forestomach, skin and mammary tumors in mice and/or rats. In this study we examine the modulatory effects of turmeric on nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis in rats. Female Wistar rats were administered NDEA (200 ppm) through drinking water (5 days per week) for 4 weeks. Control and/or NDEA-treated rats received 0, 0.2, 1.0 or 5.0% turmeric diet (w/w) either before (2 weeks), during (4 weeks) and after NDEA exposure (10 weeks) or starting from 24 h after NDEA exposure for 10 weeks. NDEA-treated rats receiving 1 or 5% turmeric before, during and after carcinogen exposure showed significant decrease in number of gamma glutamyl transpeptidase (GGT) positive foci measuring >500 or >1000 microm and decrease in the incidence of NDEA-induced focal dysplasia (FD) and hepatocellularcarcinomas. Decrease in the number of GGT positive foci measuring >1000 microm was also observed in NDEA-treated rats receiving 0.2% turmeric, although no decrease in tumor incidence was noted. On the other hand, similar levels of turmeric treatment (0.2, 1 and 5%) after exposure to NDEA did not show any protective effects. The underlying mechanism(s) of chemoprevention of NDEA-induced hepatocarcinogenesis need to be explored.
Thapliyal
R
R
Carcinogenesis Division, Cancer Research Institute, Tata Memorial Center, Parel, Mumbai 400 012, India
Naresh
K N
KN
Rao
K V K
KV
Maru
G B
GB
D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage / Q000494:pharmacology; D001835:Body Weight / Q000187:drug effects; D030024:Curcuma; D004032:Diet; D004052:Diethylnitrosamine / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005260:Female; D015994:Incidence; D008099:Liver / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced* / Q000517:prevention & control*; D009929:Organ Size / Q000187:drug effects; D010936:Plant Extracts / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D027343:Rhizome / Q000737:chemistry
D016588:Anticarcinogenic Agents; D010936:Plant Extracts; D004052:Diethylnitrosamine