In Vitro and in silico studies to explore potent antidiabetic inhibitor against human pancreatic alpha-amylase from the methanolic extract of the green microalga Chlorella vulgaris

Today’s era and lifestyle have led to a quick rise in cases of diabetes. Diabetes mellitus (DM) has risen to the top of the list of serious diseases and stems from different health disorders. Human pancreatic alpha-amylase (HPA) enzyme plays a critical role in the digestion of carbohydrates, and inhibitors of alpha-amylase have been investigated as a way to slow the absorption of carbohydrates and reduce postprandial (after meal) hyperglycemia in patients with diabetes. Recently algal derivatives have been studied for their potential as a new drug against diabetes and other diseases. The study is aimed to find active biochemical compounds from the methanolic extract of Chlorella vulgaris. The in vitro studies were carried out and the results revealed that methanolic extract from C. vulgaris showed abundant inhibition efficacy of the α-amylase (IC₅₀ of about 2.66 µg/mL) compared to acarbose (IC₅₀ of about 2.85 µg/mL), a standard, commercial inhibitor. All the bioactive compounds from the methanolic extract were identified from the GCMS study and considered for in silico evaluation. Out of 14 bioactive compounds from GCMS, compound C3 showed higher docking energy (-8.3 kcal/mol) compared to other compounds. Subsequently, the comparative molecular dynamic simulation of apo and ligand-bound (compound C3 and acarbose) α-amylase complexes showed overall structural stability for compound C3 at the active site of α-amylase from various MD analyses. Hence, we believe, the bioactive compounds identified from GCMS may assist in diabetic therapeutics. Moreover, the compound C3 identified in this study could be a potential antidiabetic therapeutic inhibitor. Communicated by Ramaswamy H. Sarma.