Inhibitory of α-glucosidase and molecular docking of white tea polyphenol (Camellia sinensis): Comparison of several solvent modifications and chemometrics approach

Abstract

Diabetes type 2 is a metabolic disease with an increasing prevalence. White tea is produced from Camellia sinensis L. Kuntze, has a high content of phenolic compounds, and has the potential to inhibit the enzyme α-glucosidase. The study was designed to study variations of solvent modification on total phenolic content (TPC) levels, total flavonoid content (TFC), and in vitro inhibitory effects. Modification of solvents as independent variables includes cold water, hot water, ethanol, cold citric acid, and hot citric acid. Ethanol solvent has the highest TPC and TFC content. Cold citric acid can increase TPC, TFC, and α-glucosidase inhibition compared to cold water. The smallest α-glucosidase IC50 value was found in ethanol solvent followed by cold citric acid. Principle component analysis (PCA) and cluster analysis (CA) indicated that ethanol and cold citric acid solvents had the highest similarity, and the TPC response was negatively correlated with IC50 α-glucosidase. In silico studies using molecular docking, the approach showed a strong bond between the catechins and the α-glucosidase active site. In conclusion, the type of solvent in the extraction process affects TPC, TFC, and IC50 α-glucosidase. Modifying acid solvents in the extraction of white tea can be considered a potential opportunity for further development.