Inhibition of α-Glucosidase Activity and Regulation of Blood Glucose by Methanol Extracts from Amomum tsao-ko

Objective: To investigate α-glucosidase inhibitory and high blood glucose regulation of methanol extracts from Amomum tsao-ko in aged mice. Methods: Using 4-N-trophenyl-α-D-glu-copyranoside(PNPG) method with acarbose as positive control, α-glucosidase inhibition test in vitro was carried out to evaluate α-glucosidase inhibition rate of methanol extract from Amomum tsao-ko. The mouse model of abnormal blood glucose was established by feeding mice with high-fat diet. On the basis of high-fat diet, 100 and 200 mg/kg of methanol extracts from Amomum tsao-ko were added for 6 weeks to evaluate the effects of methanol extracts from Amomum tsao-ko on fasting blood glucose, glucose tolerance and insulin resistance in mice. Results: When the concentration of methanol extracts solution was 500 mg/L, the inhibition rate of α-glucosidase reached 63.72%. Half inhibitory concentration (IC₅₀) of methanol extract from Amomum tsao-ko on α-glucosidase was 0.145 mg/mL. The fasting blood glucose of mice in the herb group began to decrease and maintain stability after 2 weeks of intervention by intragastric administration of low and high dose methanol extracts of Amomum tsao-ko groups. The area under the curve (AUC) values of glucose tolerance curve in low and high dose methanol extracts of Amomum tsao-ko groups after 6 weeks intervention were lower than that of model group (P<0.05). Conclusion: Methanol extracts of Amomum tsao-ko could obviously inhibit α-glucosidase activity and improve glucose tolerance in mice.