In Vitro Inhibitory Potential Against Key Enzymes Relevant for Hyperglycemia and Hypertension of Red Pepper (Capsicum annuum L.) Including Pericarp, Placenta, and Stalk

Extracts from the pericarp, placenta and stalk of red pepper (Capsicum annuumL) were investigated to determine their antioxidant and in vitro inhibitory potential against key enzymes relevant for hyperglycemia and hypertension. We examined the total phenolic and capsaicin content in red pepper extract. Anti-hyperglycemia relevant in vitro alpha-glucosidase inhibitory activity correlated strongly to the antioxidant activity measured by the 1, 1-diphenyl-2-picrylhydrazyl method. The high phenolic and capsaicin content-containing red pepper stalk was found to have strong alpha-amylase and strong alpha-glucosidase inhibitory effects. The pericarp and placenta had high angiotensin I-converting enzyme (ACE) inhibitory activity and also had good alpha-glucosidase inhibitory profiles. Inhibition of these enzymes provides a strong biochemical basis for the management of type 2 diabetes by controlling glucose absorption and reducing associated hypertension, respectively. Practical Applications The inhibitory effect on key enzymes relevant for hyperglycemia (alpha-glucosidase and alpha-amylase) and hypertension (ACE) of the red pepper pericarp, placenta and stalk was investigated in this study. The in vitro inhibitory activities of alpha-amylase, alpha-glucosidase and ACE provide a strong biochemical rationale for further in vivo studies for type 2 diabetes through the control of glucose absorption and for the reduction of the associated hypertension. Furthermore, red pepper stalk, which has always been considered as an agricultural waste product, was an effective inhibitor of alpha-glucosidase and alpha-amylase. This study shows the potential of this agricultural waste product as a food additive and therapeutic agent for clinical applications.