Sm. Khoja et Zmh. Marzouki, EFFECT OF VITAMIN-C AND VITAMIN-E INTAKE ON PLASMA-LIPID CONCENTRATIONS IN RATS, Annals of saudi medicine, 14(5), 1994, pp. 371-374
Changes in the plasma lipid levels were investigated among rats fed an
atherosclerotic-promoting diet containing 0.5% cholesterol and rats f
ed the same diet with added vitamin C (ascorbic acid), vitamin E (a-to
copherol) and vitamins C + E from one to seven weeks. Total cholestero
l (TC) and triglycerides (TG) were significantly increased in rats fed
a hyperlipidemic diet from the third week to the seventh week, wherea
s high density lipoprotein cholesterol (HDL-C) was not affected. Rats
supplemented with 5 mg vitamin C, 5 mg vitamin E or 5 mg vitamin C + 5
mg vitamin E per day for four to seven weeks showed significant decre
ase in the concentration of TC and TG. HDL-C was only affected at the
seventh week with vitamin C alone, whereas it was significantly increa
sed with vitamin E alone and vitamins C + E at five to seven weeks. Ho
wever, supplementation of vitamins C, E or C + E for less than four we
eks has no significant effect on plasma lipid concentrations. The anti
oxidant effect of vitamins C and E is probably a time-dependent proces
s that significantly lowers plasma lipids between week four and week s
even following administration of these vitamins. It is therefore sugge
sted that the incidence of coronary heart disease (CHD) may be reduced
in lowering plasma lipid levels by dietary supplementation of vitamin
s C or E.