Antiatherogenic and antiperoxidative effects of garlic and soy proteins in alcohol fed rats.

Rats fed with alcohol (18%) at 3.76 g/day for 45 days showed significant reduction in body weight, glutathione (GSH) content and activities of superoxide dismutase (SOD) and catalase in liver. Lecithin cholesterol acyltransferase (LCAT) in plasma, levels of HDL cholesterol in serum, hepatic bile acid production and fecal excretion of neutral sterols also showed significant reduction. Simultaneous feeding of garlic protein (GP) or soy protein (SP) (500 mg/kg body weight/day for 45 days) to alcohol fed groups increased each of above parameters significantly towards normal values. Increase in GSH content and catalase activity in liver, was significantly higher for SP treated group than for GP treated group. However, increase in plasma LCAT was significantly higher for GP treated group than for SP treated group. Alcohol fed rats showed significant increase in liver weight, serum and tissue cholesterol, serum triacylglycerol (TAG), phospholipids (PL) and free fatty acid (FFA) levels and activity of HMGCoA reductase in liver and intestine. Lipid peroxidation, glucose-6 phosphate dehydrogenase (G6PD), glutathione peroxidase (GPx) and glutathione reductase (GR) in liver and incorporation of labeled acetate into liver cholesterol also showed significant increase. GP and SP treated rats showed decrease in these values towards normal. GP feeding showed a better effect than SP in lowering serum and heart total cholesterol, and in maintaining GPx at near normal level, while SP feeding showed a better effect in lowering serum FFA level and maintaining GR activity at near normal level. In suppressing incorporation of labeled acetate into serum cholesterol, GP feeding showed a better effect than SP. Antiatherogenic and antiperoxidative effects of these proteins may be due to lower lysine/arginine ratio.

Antioxidant role of oils isolated from garlic (Allium sativum Linn) and onion (Allium cepa Linn) on nicotine-induced lipid peroxidation.

Nicotine, a major component of tobacco, is partly responsible for the development of atherosclerosis. It has been suggested that antioxidant nutrients are protective against degenerative diseases. So we have studied the antioxidant effect of oils isolated from onion and garlic on nicotine-induced lipid peroxidation in rat tissues. The lipid peroxidation products and scavenging enzymes were assessed in liver, lungs, heart and kidney. The rats were treated with 0.6 mg nicotine/kg bw and simultaneously given 100 mg garlic or onion oils/kg bw for 21 d. Thiobarbituric acid reactive substances, conjugated dienes and hydroperoxides concentrations were significantly increased in the tissues of nicotine-treated rats. Both the garlic oil and onion oil supplementation to nicotine-treated rats increased resistance to lipid peroxidation. The activities of catalase, superoxide dismutase and glutathione peroxidase decreased in nicotine-treated rats, but there was a trend to increased glutathione content. With garlic oil or onion oil supplementation, nicotine-treated rats had increased activities of antioxidant enzymes and increased concentrations of glutathione. These results indicate that oils of garlic and onion are effective antioxidants against the oxidative damage caused by nicotine.

Biochemical effects of garlic protein on lipid metabolism in alcohol fed rats.

Garlic protein is a very good hypolipidemic agent. In the present study the water soluble protein fraction of garlic was investigated for its effect on hyperlipidemia induced by alcohol (3.76 g/kg. body wt./day). The hypolipidemic action is mainly due to an increase in cholesterol degradation to bile acids and neutral sterols and mobilization of triacyl glycerols in treated rats. Garlic protein (500 mg./kg body wt./day) showed significant hypolipidemic action comparable with a standard dose of gugu-lipid (50 mg./kg. body wt./day).

Antiperoxide effect of garlic protein in alcohol fed rats.

Rats fed ethanol (3.76g/Kg body wt/day) for about 45 days exhibited high levels of tissue malondialdehyde, hydroperoxide and diene conjugates. Activity of tissue superoxide dismutase, catalase, and glutathione content decreased. Administration of water soluble proteins of garlic (500 mg/kg body wt/day) to alcohol fed rats showed significant increase in antiperoxide activity and decrease in the activity of glutathione peroxidase and glutathione s transferase as compared to a standard drug gugulipid (50 mg/kg body wt/day).