Evaluation of herbal foods on alpha-glucosidase activity and glycemic index

The inhibitory effects on α-glucosidase (AGH) and the glycemic index (GI) of four lyophilized herbal samples and five herbal tea samples were evaluated in terms of their efficacy for developing therapeutic diets for patients with diabetes. The AGH activity of these samples was evaluated in vitro using an immobilized enzyme (iAGH) that imitated the small intestinal membrane (Kawada et al., 2006). Lyophilized herbal samples, including dill, Italian parsley, corn salad, and rocket, inhibited AGH activity. The GI of the lyophilized samples of Italian parsley, corn salad, rocket, and the raw samples of dill, corn salad, and rocket, was on average less than 100, but not statistically significant. Moreover, all herbal tea samples inhibited AGH activity, and the GI of lemon balm was only slightly reduced, but not statistically significant. In this paper, we discuss the possible application of herbal foods as dietary therapy for patients with type 2 diabetes.