New insights into the in vitro, in situ and in vivo antihyperglycemic mechanisms of gallic acid and p-coumaric acid.

Objective: To explore the probable in vitro, in situ and in vivo mechanisms of gallic acid (GA) and p-coumaric acid (PCA) as anti-hyperglycemic agents.Animals and methods: Male albino rats were allocated into four groups, group1 was used as normal control. Group 2 was established as a diabetic control and group3 and 4 were treated with an oral dose of GA and PCA, respectively.Results: GA and PCA revealed a significant decrease in the activity of α-amylase, a noticeable rise in glucose induced-insulin secretion and glucose-uptake in peripheral glucose-uptake in vitro, increase also liver glycogen and serum insulin levels in vivo. Further, GA and PCA exhibited a significant reduction in intestinal glucose absorption in situ compared to blank.Conclusion: The antihyperglycemic activities of GA and PCA can be mediated through delaying intestinal glucose absorption, enhancing β-cell activity and promoting glucose uptake by peripheral tissue via enhancing insulin sensitivity.