Inhibition of Alpha‐glucosidase by guava (Psidium guajava)

Abstract

Diabetes mellitus is a disorder of carbohydrate regulation related to either of the following: reduced pancreatic insulin production, peripheral insulin resistance, or an impaired regulation of hepatic glucose production. Due to their insulin disorder, patients diagnosed with diabetes mellitus are unable to properly conduct cellular uptake and utilization of glucose as an energy source which ultimately leads to hyperglycemia. Several categories of pharmacological treatments exist today to treat diabetes mellitus. However, they all have adverse effects. Our screening program aims at finding alternative local herbs that can treat diabetes. The herb that will be used in this study is guava (Psidium guajava L., Myrtaceae) leaves. Guava leaf extracts are said to be helpful for people with diabetes. A previous study conducted on guava leaves and its antidiabetic effect indicated that guava leaf polysaccharides (GLP) demonstrated antidiabetic capabilities. The anti-diabetic effects of GLP was shown to be related to a decrease in fasting blood sugar while also improving kidney, liver, and pancreas damage related to diabetes. Using guava extracts as a herbal alternative to manage diabetes will remarkably decrease the expense and complications associated with present medications used for diabetes management. The purpose of this study was to examine the mechanism of action of guava fruit as an inhibitor of alpha-glucosidase. The IC50 of Guava was compared with acarbose which is a proven antidiabetic agent known for lowering post-prandial hyperglycemic level by inhibiting α-glucosidase. In this study, we investigated the mechanism of action of guava fruit by in vitro method. The inhibition study was carried out in a 96 well plate using PNPG as the substrate and measured with Thermo Scientific® Multiskan Spectrometer. The EC50 was obtained and compared with that of acarbose. The result showed that guava fruit has some inhibitory activity on α-glucosidase. However, more studies are to be carried out.