Xanthine derivatives as activators of alpha-amylase: hypothesis on a link with the hyperglycemia induced by caffeine.

Inhibitors of the mammalian alpha-amylases have been widely studied as medicines to be used in diabetes and obesity. However, there are few reports on activation of the enzyme, which could be detrimental in those conditions. Here, the effect of purine-derivated compounds has been studied on porcine pancreatic alpha-amylase. Methylxanthine-derivatives pentoxyfilline, theobromine and caffeine caused a 20-30% increase in enzyme activity in the presence of the natural substrate, starch. The activation effect was not dose-dependent, observed in the range of 10-200 μM of the compounds, and hypothesized to be related with the hyperglycemia that is observed upon consuming caffeine.