Phytochemicals, Antidiabetic, and Antioxidant Activities of Syzygium polyanthum Achieved by GC-MS Analysis, α-Glucosidase Inhibition and Kinetic Mechanism along with a Free Radicals Scavenging Activities

In the pursuit of effective antidiabetic agents with dual α-glucosidase inhibition and free radical scavenging properties, Sygyzium polyanthum has demonstrated promising bioactivity based on the specified criteria. Analysis using GC–MS of n-hexane, dichloromethane, ethyl acetate, methanol residue, and aqueous extracts from S. polyanthum leaf revealed the presence of various phytochemicals with associated biological activities. This study represents the first investigation into the assessment of antidiabetic potential through rat intestinal α-glucosidase inhibitory activity and the kinetic mechanism of S. polyanthum leaf. The aqueous extract exhibited simultaneous inhibition of rat intestinal α-glucosidase (with IC50 values of 0.09 mg/mL and 0.97 mg/mL for maltase and sucrase, respectively) and free radicals (with SC50 values of 0.05 mg/mL, 0.26 mg/mL,0.95 mg/mL, and 0.19 mmol/g for DPPH, ABTS, nitric oxide, and CUPRAC, respectively). Notably, the aqueous extract competitively and non-competitively inhibited maltase, while it inhibited sucrase in an uncompetitive manner. Furthermore, molecular docking analysis of secondary metabolites found that quinoline, 1,2,3,4-tetrahydro-1-((2-phenylcyclopropyl) sulfonyl)-, trans- showed binding interaction with amino residues of protein. Moreover, the presence of bioactive compounds supports the traditional use of plant leaf for treating various diseases with minimal side effects, and underscores the pharmaceutical significance of the plant.