Study on α-glucosidase enzyme inhibitory activity and DPPH free radical scavenging of green coffee bean extract (Coffea canephora)
Authors: Thu Dang Kim , Hung Vu Manh , Trang Nguyen Thi , Thanh Tung Bui 
Published: December 2019

Abstract: α-glucosidase enzyme is one of the important molecular targets in the treatment of diabetes. In addition, free radicals are the cause of insulin resistance, damage β- cell pancreatic, glucose uptake disorders and induced diabetes. In this study we evaluated the inhibitory effect of α-glucosidase enzyme and antioxidant effect by using DPPH free radical scavenging method of green coffee bean extract (Coffea canephora) and its fractions. Coffee beans were pulverized, extracted with ethanol 70% by sonications, and fractionated with n-hexane, ethyl acetate (EtOAc) and n-butanol (n-BuOH) solvents. Our results showed that coffee bean extract has a strong α-glucosidase enzyme inhibitory activity, especially EtOAc fraction with an IC50 value of 2.21 ± 0.04 µg/mL. Furthermore, the coffee bean extract has an antioxidant effect by DPPH radical scavenging ability, and EtOAc fraction has the highest effect with an IC50 value of 25.69 ± 3.08 µg/ml. Our results show that green coffee beans and EtOAc fraction have potential effect in preventing and supporting for the treatment of diabetes.
Keywords
Coffee; Coffea canephora; free radical; α-glucosidase; DPPH.
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