In this study, a team of researchers uncover the mechanism behind catechu’s hypoglycemic effect.
Type 2 diabetes mellitus is a disorder that affects almost 400 million people worldwide and accounts for the majority (~90 per cent) of all diabetes occurrences. It is characterised by high and/or fluctuating blood glucose due to insufficient insulin secretion and/or resistance. Diabetes is a chronic condition that is accompanied with severe complications such as high blood pressure, kidney failure, heart disease, and so on. Therefore, enhancing glucose uptake by organs or tissues or inhibiting the activities of enzymes α-glucosidase and α-amylase that increase glucose levels are major strategies in diabetes management.
The Senegalia catechu, generally known as Acacia catechu, is a deciduous tree found in parts of South Asia and Southeast Asia. Traditionally, it has been used as herbal medicine in India and China to treat diabetes. Recent studies have found that the bark, wood, and seeds from S. catechu possess pharmacological activities including hypoglycemic, hepatoprotective, and antimicrobial activities. However, much remains to be known about the hypoglycemic mechanism and corresponding constituent of S. catechu.
Recently, a team of researchers from Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences endeavoured to explore the hypoglycemic effect of S. catechu by conducting glucose uptake assay, and α-glucosidase and α-amylase inhibition experiments.
Catechu is the dry water extract of barked branches or stems from S. catechu and has been used in traditional research to manage glucose levels. In this study, the team wanted to find the active constituents and investigate the possible mechanism supporting catechu’s traditional usage.
To do this, the researchers divided ethanol extract (EE) of catechu into petroleum ether fraction of EE, ethyl acetate fraction of EE, and n-Butanol fraction of EE fractions by polarity, and observed their hypoglycemic activities through assays for α-glucosidase, α-amylase, and glucose uptake in adipocytes.
Then, to analyse the primary active ingredients and the possible mechanisms against enzymes, the team carried out high-performance liquid chromatography-mass spectrometry (HPLC-MS) and in silico molecular docking investigations. The results reveal that all fractions except petroleum ether presented significant inhibitory effects on α-glucosidase and α-amylase and that none of the fractions promoted the glucose uptake rate of adipocytes.
The team’s work suggests that the hypoglycemic effect of catechu might be related to the inhibitory effects of phenols ((-)-epicatechin, cyanidin, delphinidin, and their derivatives) on digestive enzymes, providing scientific evidence for catechu’s traditional use to type 2 diabetes mellitus.
Source: Zhang et al. (2022). Antidiabetic potential of Catechu via assays for α-glucosidase, α-amylase, and glucose uptake in adipocytes. Journal of Ethnopharmacology, 291, 115118.