Diabetes mellitus is one of the most common endocrine diseases and its type II is the major form of diabetes. One of the beneficial therapies for type II is said to be the control of postprandial hyperglycemia after a meal. The best therapeutic approach to decrease postprandial hyperglycemia is to retard absorption of glucose through inhibition of carbohydrate hydrolyzing enzymes (such as a-amylase) in the digestiveorgans. In recent years, research on natural enzyme inhibitors from plant sources hasoffered an attractive strategy for the control of postprandial hyperglycemia. The edible Allium species are of major economic and dietary importance in all parts of theworld. The antidiabetic property of some Allium species has been studied by some scientists. The aim of this study was to examine the in vitro α-amylase inhibitory potency of some Allium species and compare them with each other.
The ethanol extracts obtained from six Allium including A. akaka Gmel., A. ampeloprasum L. subsp. iranicum, A. cepa L., A. hirtifolium Boiss., A. porrum L. and A. sativum L. were tested against a-amylase and inhibitory activity of each extract, expressed as IC50 values, calculated from Log concentration-response curve. As positive control acarbose was used. The results were statistically compared by oneway ANOVA to see the significance.
According to the results, ethanol extracts of A. akaka, A. cepa, A. porrum and A. sativum were found to have a favorable a-amylase inhibitory activity with IC50 values of 16.74, 17.95, 15.73 and 16.36 mg/ml, respectively and they did not reveal any significant differences in their IC50 values (P>0.05). However, the two other Allium species tested (A. ampeloprasum subsp. iranicum and A. hirtifolium) did not show valuable inhibitory activity. These findings support the hypoglycemic activity of some Allium species and give insight about the potential mechanism of their hypoglycemic activity.