Hypoglycemic and antioxidant properties of konjac (Amorphophallus konjac) in vitro and in vivo.

Abstract

The aim of this study was to evaluate the hypoglycemic and antioxidant potential of konjac in vitro and in vivo. Glucose diffusion and enzymatic starch digestion of konjac were assayed using α-amylase and α-glucosidase. Oral glucose tolerance test (OGTT) and oral starch tolerance test (OSTT) were performed at dose of 102mg/Kg of body weight (equivalent to 1g/meal in humans). Additionally, the antioxidant activity of konjac was evaluated through inhibition of lipid peroxidation. The konjac decreased glucose diffusion by 36% and 19% compared with the negative and positive controls, respectively. Additionally, konjac inhibited α-amylase and α-glucosidase activities by 14% and 90%, respectively. After OSTT, group treated with konjac showed significant lower glucose levels compared with control group (p=.03). Finally, konjac reduced lipid peroxidation in human plasma (93%) compared with the negative control. Our results suggest that konjac exhibits hypoglycemic and antioxidant activities in vitro and in vivo. PRACTICAL APPLICATIONS: Because the use of herbal products have emerged as an attractive therapeutic option for chronic diseases, konjac administration may be an adjuvant for the treatment of type 2 diabetes.