Chemopreventive effect of garlic powder diet in diethylnitrosamine-induced rat hepatocarcinogenesis.
This study was conducted to examine the effects of dietary garlic powder at the different levels on preneoplastic foci formation and glutathione (GSH)-dependent detoxifying enzyme activities in rat hepatocarcinogenesis. Male Sprague-Dawley rats were fed with garlic powder supplemented diets (0, 0.5, 2.0 or 5.0%) for 11 weeks, and induced hepatocarcinogenesis by diethylnitrosamine (DEN) and two-thirds partial hepatectomy in medium-term bioassay system. The 2.0 and 5.0% garlic powder diets suppressed the formation of placental GSH S-transferase positive (GST-P(+)) foci in number (49.7 and 63.1% of DEN-treated control group, respectively) and area (44.2 and 63.9% of DEN-treated control group, respectively). Total GSH content in 2.0% garlic powder diet group was 1.2 fold higher than that in DEN-treated control group. GSH S-transferase activity of 2.0% garlic powder diet group was lower than that in DEN-treated control group, and GSH peroxidase (GPx) activity was significantly increased by garlic powder diets (83 and 164% of DEN-treated control group, respectively). GSH reductase activity, however, did not show a noticeable difference among groups. Therefore, the suppression of GST-P(+) foci formation by garlic powder diets could be partly affected by the increase of total GSH content and GPx activity.
Kweon
Sanghui
S
Department of Food and Nutrition, Seoul National University, Shillim-dong, Kwanak-gu, Seoul 151-742, South Korea.
Park
Kyung-Ae
KA
Choi
Haymie
H
D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D019587:Dietary Supplements; D004052:Diethylnitrosamine / Q000633:toxicity; D005737:Garlic; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D015227:Lipid Peroxidation; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology / Q000517:prevention & control*; D008297:Male; D011208:Powders; D051381:Rats; D017207:Rats, Sprague-Dawley
D016588:Anticarcinogenic Agents; D011208:Powders; D004052:Diethylnitrosamine; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase