Anticarcinogenic effect and modification of cytochrome P450 2E1 by dietary garlic powder in diethylnitrosamine-initiated rat hepatocarcinogenesis.
The purpose of this study was to determine the effects of dietary garlic powder on diethylnitrosamine (DEN)- induced hepatocarcinogenesis and cytochrome P450 (CYP) enzymes in weaning male Sprague-Dawley rats by using the medium-term bioassay system of Ito et al. The rats were fed diets that contained 0, 0.5, 2.0 or 5.0% garlic powder for 8 weeks, beginning the diets with the intraperitoneal (i.p.) injection of DEN. The areas of placental glutathione S-transferase (GST-P) positive foci, an effective marker for DEN-initiated lesions, were significantly decreased in the rats that were fed garlic powder diets; the numbers were significantly decreased only in the 2.0 and 5.0% garlic-powder diets. The p-Nitrophenol hydroxylase (PNPH) activities and protein levels of CYP 2E1 in the hepatic microsomes of the rats that were fed the 2.0 and 5.0% garlic powder diet were much lower than those of the basal-diet groups. Pentoxyresorufin O-dealkylase (PROD) activity and CYP 2B1 protein level were not influenced by the garlic-powder diets and carcinogen treatment. Therefore, the suppression of CYP 2E1 by garlic in the diet might influence the formation of preneoplastic foci during hepatocarcinogenesis in rats that are initiated with DEN.
Park
Kyung-Ae
KA
School of Human Ecology, Kaya University, Koryong, Kyungbuk 717-800, Korea.
Kweon
Sanghui
S
Choi
Haymie
H
D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D019362:Cytochrome P-450 CYP2B1 / Q000378:metabolism; D019392:Cytochrome P-450 CYP2E1 / Q000378:metabolism* / Q000494:pharmacology*; D004052:Diethylnitrosamine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005737:Garlic / Q000378:metabolism*; D005952:Glucose-6-Phosphatase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D015151:Immunoblotting; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000139:chemically induced* / Q000378:metabolism / Q000517:prevention & control*; D008297:Male; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D016588:Anticarcinogenic Agents; D010936:Plant Extracts; D004052:Diethylnitrosamine; D019392:Cytochrome P-450 CYP2E1; D019362:Cytochrome P-450 CYP2B1; D005982:Glutathione Transferase; D005952:Glucose-6-Phosphatase