Effects of beta-carotene and retinyl palmitate on corn oil-induced superoxide dismutase and catalase in rats.
The present study was undertaken to determine the effects of beta-carotene on corn oil-induced superoxide dismutase and catalase. Six groups of male Buffalo rats were fed the following diets for 6 wk: a control diet containing recommended levels of beta-carotene and retinyl palmitate, a retinol diet containing 10 times the recommended level of retinyl palmitate, and a beta-carotene diet containing 10 times the recommended levels of beta-carotene and adequate levels of retinyl palmitate. Each vitamin combination was fed with either 5% (wt/wt) corn oil (low fat) or 20% corn oil (high fat). Plasma total beta-carotene levels were highest in the beta-carotene groups. Levels varied inversely with the level of fat in the control group and directly with fat in the beta-carotene group. Transport of beta-carotene appeared to parallel that of cholesterol in that 36 and 35%, respectively, were associated with the low density lipoprotein fraction. Accumulation of beta-carotene in the liver was apparent from the observation that levels in liver were much higher than those in plasma. Superoxide dismutase activity was much lower in the beta-carotene groups than in the retinol groups, irrespective of level of fat, and catalase activity was also lower in the beta-carotene group, but it was in proportion to the level of fat. These findings suggest that beta-carotene functions as an antioxidant in vivo.
Blakely
S R
SR
Department of Biochemistry, College of Medicine, School of Human Ecology, Howard University, Washington, DC 20059.
Slaughter
L
L
Adkins
J
J
Knight
E V
EV
D000284:Administration, Oral; D000818:Animals; D002338:Carotenoids / Q000378:metabolism / Q000494:pharmacology*; D002374:Catalase / Q000096:biosynthesis*; D008076:Cholesterol, HDL / Q000097:blood; D003314:Corn Oil / Q000037:antagonists & inhibitors; D004224:Diterpenes; D004790:Enzyme Induction / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008114:Liver Neoplasms, Experimental / Q000201:enzymology; D008297:Male; D051381:Rats; D011915:Rats, Inbred BUF; D000084562:Retinyl Esters; D013482:Superoxide Dismutase / Q000096:biosynthesis*; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000494:pharmacology; D019207:beta Carotene
D008076:Cholesterol, HDL; D004224:Diterpenes; D000084562:Retinyl Esters; D019207:beta Carotene; D014801:Vitamin A; C014794:retinol palmitate; D002338:Carotenoids; D003314:Corn Oil; D002374:Catalase; D013482:Superoxide Dismutase