Effects of Two Hypocaloric Diets Supplemented With White Lupine or Oats on Lipid Peroxidation, Reverse Cholesterol Transport and Paraoxonase Activity in Obese Rat

The purpose of this study was to compare the effects of two hypocaloric diets supplemented with legume or cereal on hyperglycemia, dyslipidemia, serum HDL2 and HDL3 composition, lipid peroxidation, and lecithin-cholesterol acyltransferase (LCAT) and paraoxonase (PON1) activities in obese rats. Obesity was induced by feeding a high-fat-diet during 3 months. At 400 ± 20 g, the obese rats were divided into three groups (n = 8): two groups were submitted for 28 days to a caloric restriction (CR) at 0.9 MJ supplemented with lupine (CR–Lupine group) or oats (CR–Oats group). The third group was fed a caloric restricted diet without supplementation (CR group). At day 28, glycemia was lower (-21%) in the CR–Oats than the CR group. CR–Oats diet reduced total cholesterol content (-13%) when compared to lupine supplementation. In contrast, CR–Lupine diet decreased serum triacylglycerols by 22% and 15% respectively versus CR–Oats and CR diets. Lipoproteins lipid peroxidation was significantly lower in CR–Lupine and CR–Oats when compared to the CR diet. Serum PON1 activity was increased in CR–Lupine (+88%) and CR–Oats (+82%) groups compared to CR group. Furthermore, LCAT activity was enhanced in CR– Lupine (+23% and +26%, respectively) versus CR and CR–Oats groups. In obese rats, caloric restriction supplemented with lupine compared to oats supplementation has beneficial effect on hypertriglyceridemia and improves reverse cholesterol transport by enhancing LCAT activity leading to anti–atherogenic effects. This effect is partially reinforced by the high HDL PON1 activity which protects it from oxidation.