Inhibition of In Vitro Fructose-Induced Protein Glycation by Litchi chinensis

Abstract

Non enzymatic glycation is a chain reaction between reducing sugars and the free amino groups of proteins, involved in severity of diabetes and diabetic complications. Litchi chinensis used as consumed fruit and as a drug to treat certain diseases. In this study the antioxidative effects of L.chinensis and also its effect against protein oxidation and advanced glycation end products. The antioxidant potential of aqueous fruit pericarp extract of L.chinensis (APLC) was evaluated in vitro using a model of fructose-mediated protein glycation. The antioxidant activity of APLC conducted for superoxide, hydroxyl, hydrogen peroxide, nitric oxide radical scavenging activities and also demonstrated antioxidant activity with Fe+2 chelating activity, ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) were applied. Fructose (100mM) increased fluorescence intensity of glycated bovine serum albumin (BSA) in terms of total AGEs during 21 days of exposure. Moreover, fructose caused more protein carbonyl (PCO) formation in native BSA. The APLC prevents oxidative protein damages including effect on PCO formation which are believed to form under the glycoxidation process. The APLC at different concentrations (25-250µg/ml) has significantly decreased the formation of AGEs in term of the fluorescence intensity of glycated BSA.