Radical scavenging, anti-inflammatory and glucose metabolising enzymes activity of Secamone afzelii K. leaf and vine: In vitro and in silico studies

Secamone afzelii is commonly used in folk medicine as a galactagogue infusion for pain relief and diabetes management. This study investigated the hydroethanol extracts of S. afzelii leaf (SALE) and vine (SAVE) for their phytochemical content, radical scavenging abilities, anti-inflammatory properties, and inhibitory effects against α-amylase and α-glucosidase. Furthermore, the phytocompounds responsible for the enzyme inhibitory activity and their mechanisms were assessed using molecular docking to validate in vitro findings. Tannins, alkaloids, flavonoids, and phenols were detected, while terpenoids and glycosides were not present in both S. afzelii extracts. The total content of β-carotene, lycopene, phenolics, flavonoids, and flavanols in SALE was greater than in SAVE. Similarly, SALE exhibited superior radical scavenging activities, antioxidant capacities, albumin denaturation protection, and red blood cell haemolysis protection properties. A dose-dependent inhibition of α-glucosidase and α-amylase activity was observed in the extracts, with the α-amylase inhibitory activity of SALE significantly higher than that of SAVE. However, no difference was found in the α-glucosidase inhibitory properties among SALE, SAVE, and acarbose. S. afzelii demonstrated a respective noncompetitive and uncompetitive mode of inhibition on α-amylase and α-glucosidase activities, validated by molecular docking. The compounds 5α-androstan-16-one, cyclic ethylene mercaptole, oxalic acid, mono-{5-[(2-bromophenyl)(2,2-dimethylpropionyloxy)methyl]-7,8-dihydro-5H-[1,3]dioxolo[4,5-g]isoquinolin-6-yl} ester, guanosine, and glucosamine, N-acetyl-N-benzoyl- were identified as responsible for the α-glucosidase and α-amylase inhibitory activity of SALE and SAVE based on their binding energy. Therefore, S. afzelii could be explored as a natural alternative source for managing diabetes mellitus-induced postprandial hyperglycaemia and its downstream inflammatory and oxidative stress complications.