Fayçal DJELLOULI

The beneficial health effects of plant polyphenols were frequently attributed to their powerful hypolipemiant and antioxidant effects. We hypothesized that administration of Globularia alypum (Ga) lyophilized methanolic extract would ameliorate glycemia, lipid parameters, reverse cholesterol transport, as well as lipoproteins peroxidation, in diabetic rats. Diabetes was induced in male Wistar rats, weighing 250±10 g by a single intraperitoneal injection of streptozotocin (STZ) (55 mg/kg body weight). Diabetic rats (n=20) were divided into two groups, and fed during 4 weeks diets containing 20% casein (D) or a casein diet supplemented with a Ga extract (1 g/kg BW) (DGa). At d28, in DGa vs D group, glycemia was lowered by 81%, while insulinemia was markedly increased by 72%. Liver and serum lipid values were significantly decreased (P< 0.05). Lecithin:cholesterol acyltransferase (LCAT) activity was improved (+48%). Indeed, HDL3-PL (enzyme substrate) and HDL3-UC (acyl group acceptor) concentrations were respectively reduced by 50 and 52%, whereas HDL2-CE values (product of LCAT reaction) were increased (+35%). Atherogenicity ratios VLDL-LDL-C/HDL-C, TC/HDL-C and apoB/apoA were lowered respectively by 50%, 25% and 71%. Moreover, VLDL-LDL and HDL3peroxidation was decreased by 47 and 75%, respectively.In STZ-induced diabetic rat, Globularia alypum extract reduces glycemia, liver and serum lipids values, VLDL-LDL and HDL3 lipid peroxidation and ameliorates the reverse cholesterol transport. Therefore, Ga extract may be useful for preventing diabetes and lipid disorders.