Protective effects of organic fractions of Trachyspermum copticum against advance glycation end products in vitro

Abstract

Elevation of intracellular glucose levels results in formation of advanced glycation end products (AGEs) through nonenzymatic glycosylation in intra- and intercellular proteins, whereby the proteins lose their natural function. Reactive oxygen species are involved in the glycosylation process of proteins. Therefore, in this study, we investigated the antioxidant activity and inhibitory effect of organic fractions of Trachyspermum copticum against the formation of AGE compounds in a diabetic model under experimental conditions. The total phenol and flavonoid contents of crude extract and different fractions were measured by folin–ciocalteu and ammonium chloride, while their antioxidant activity was measured by scavenging DPPH radicals. The diabetic model was developed by glycation of bovine serum albumen under experimental conditions, and the extent of AGE formation was measured based on fluorescence absorption at excitation and emission wavelengths of 335 and 385 nm, respectively. Protein carbonyl oxidation (PCO) and thiol groups’ oxidation as markers of oxidative damage to proteins were also measured. Our results indicate that the ethyl acetate fraction of Trachyspermum copticum at different concentrations (10–500 μg/ml) has the high antioxidant activity. Furthermore, the fraction had the maximum inhibitory effect on formation of AGE compounds and reduction of protein oxidative degradation through reducing PCO formation and enhancing thiol groups. Accordingly, we can conclude that the ethyl acetate fraction has anti-glycation effects under in vitro conditions, which might be due to its high polyphenolic content and antioxidant properties.