Anti-glycation study of hydro-alcohol and aqueous extracts of Moroccan plant species

Inhibition of advanced glycation end products (AGEs) and free radicals generated during diabetes represents a major therapeutic target in the prevention and treatment of diabetic complications. Natural molecules present in fruits, vegetables and herbs and which are usually safe for human consumption, could represent a strong glycation inhibitor. Anti-glycation effect of nine plant species used in traditional medicine has been evaluated after extraction by hot (EAC) or cold (EAF) maceration and by ethanol (EE). Anti-glycation activity performed on a model system of bovine serum albumin, and methylglyoxal was measured by fluorescence and native electrophoresis. Total phenolic and flavonoid contents were assessed as well. Except for Sesamum indicum, all the species studied have an Anti-glycation effect. The highest effect was recorded in Laurus nobilis and was dose-dependent, inhibiting both formations of Amadori products and fluorescent AGEs. HPLC analysis revealed a richness of Laurus nobilis EE in phenolic compounds such as quercetin, vanillin and gallic acid. A strong correlation was registered between antioxidant power and phenolic/flavonoid content. In contrast, there was no correlation between antioxidant and anti-glycation power. Phenolic and flavonoid compounds were strongly involved in the observed anti-glycation effect. However, the anti-glycation activity obtained is probably attributed to non-antioxidant compounds.