ABSTRACT
Objective: To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P. americana) (traditionally used in Cameroon against diabetes) on α-glucosidase, β-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities, enzymes involved in starch digestion or diabetic complications. Methods: The methanol extracts from Piper umbellatum and P. americana were prepared by maceration. To assess relative efficacy of these extracts, the determination of concentrations that were needed to inhibit 50% of enzyme activity was done, whereas, gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities. Results: The tested extracts strongly inhibited α-glucosidase, maltase-glucoamylase, aldose reductase and aldehyde reductase activities with IC