Objective: To study on the effect of Siraitiae Fructus extracts from different growth period fruit on postprandial blood glucose levels in mice

and examine the impact on postprandial insulin and α-glucosidase enzyme activity. Method: Kuenming mice were divided into starch load (6 g · kg-1) and glucose load (2 g · kg-1) group

each group consists of 9 subgroups:normal control

starch load or glucose load control

positive control (acarbose 0.01 g · kg-1)

90 days Siraitiae Fructus extracts high

medium and low dose (1

0.5

0.25 g · kg-1)

60 days Siraitiae Fructus extracts high

medium and low dose (1

0.5

0.25 g · kg-1). The postprandial blood glucose induced by starch and glucose were observed after 7 days Siraitiae Fructus extracts administration

and the postprandial insulin levels were determined via ELISA method. Moreover

the inhibition effect of Siraitiae Fructus extracts on α-glucosidase activity was determined in vitro. Result: All dosage of 90 days and 60 days Siraitiae Fructus extracts inhibited peak value of postprandial blood glucose;all dosage of 90 days Siraitiae Fructus extracts reduced glycemic index induced by starch (P<0.05)

and the glycemic index induced by glucose was reduced at 0.25 g · kg-1(P<0.05);moreover

0.5 g · kg-1of 60 days Siraitiae Fructus extracts significantly reduced glycemic index induced by starch (P<0.01)

but all dose of 60 days Siraitiae Fructus extracts only demonstrated a trend to reduce the glycemic index induced by glucose. All dose of 90 days Siraitiae Fructus extracts significantly increased postprandial insulin (P<0.001)

and 60 days Siraitiae Fructus extracts increased postprandial insulin dose dependently. The IC50 value of 90 and 60 days Siraitiae Fructus extracts was 11.51 g · L-1 and 2.40 g · L-1

respectively. Conclusion: Mangosteen extract is effectual in the inhibition of the rapid increase of postprandial blood glucose

which are primarily mediated by increasing postprandial insulin levels andα-glucosidase inhibition

there is a difference in hypoglycemic mechanism between Siraitiae Fructus extracts from different growth period fruit.