Supplementation of garlic lowers lipids and increases antioxidant capacity in plasma of rats

The bioactivity of raw and boiled garlic (Allium sativum L.), comprising contributions from polyphenols, was determined by cupric-reducing antioxidant capacity and trolox equivalent antioxidant capacity assays. Boiling garlic at 100 degrees C for 20 minutes preserves its bioactivity and makes it comparable with the raw sample. Wistar male rats were randomly divided into 10 diet groups with garlic supplementation. The control group was fed basal diet that included wheat starch, casein, soybean oil, cellulose, mineral, and vitamin mixtures. To the basal diet of the other groups, 25 mg of lyophilized garlic equivalent to 500 mg raw garlic/kg body weight (raw) was added. The same quantity of boiled garlic for 20, 40, and 60 minutes (Gar20, Gar40, and Gar60 groups), 1% of cholesterol (Chol) and 25 mg of lyophilized raw garlic (Chol/Raw), 1% of Chol, and the same quantity of boiled garlic for Chol/Gar20, Chol/Gar40, and Chol/Gar60 groups were added, respectively. After the trial in rats of Chol/Raw and Chol/Gar20 diet groups, the added garlic significantly hindered the rise in plasma lipids. A significant increase (P < .05) in plasma antioxidant activity was registered in Raw and Gar20 diet groups. In conclusion, raw and boiled garlic at 100 degrees C for 20 minutes improved the plasma lipid levels in rats fed cholesterol-containing diets and increased the plasma antioxidant activity in groups of rats fed cholesterol-free diets. Garlic boiled for a short time can be used as an additive in cooking. (c) 2006 Elsevier Inc. All rights reserved.