Inhibition of Albumin Glycation at Different Stages by Four Anti-diabetic Plant Extracts Correlates with Polyphenols and Antioxidant Capacity in vitro

Aims: Both glycation and oxidative stress play a critical role in the incidence of diabetic complications. Plants with antioxidative and antiglycative properties may attenuate such pathological conditions. The aim of this study is comparing the antiglycative and antioxidative effects of Vaccinium arctostaphylos, Plantago ovata, Securigera securidaca and Rhus coriaria on albumin glycation for the first time.

Methodology: Antiglycative property of methanolic extract (75%) of these plants was evaluated by co-incubation of extracts with bovine serum albumin and glucose. Various stages were assessed by measuring different markers of glycation (fructosamine, protein carbonyls and amyloid cross-β structure aggregation). Total phenolic and flavonoid contents as well as antioxidant capacity of extracts were determined. Finally, the correlations between antiglycation property, total phenol and flavonoid content and antioxidant capacity of extracts were evaluated.

Results: The results demonstrated that the extracts exert inhibitory effects on various stages of glycation and V. arctostaphylos showed maximum attenuating effect. A significant correlation was found between antiglycation and antioxidant properties of extracts with total phenolic and flavonoid content. In addition, the antioxidant capacity of extracts correlated with their antiglycation properties.

Conclusion: Our findings revealed that antioxidative and antiglycative activities of extracts may be related to their phenolic and flavonoid contents. These findings support the viewpoint that the medicinal plants with anti-diabetic properties may be beneficial resources for inhibition of glycation and oxidative stress in diabetic patients.