Phytochemical Profiling and Antioxidant Potential of Cordia sinensis Lam. Extract: Integration of Phenolic-Flavonoid Quantification, In Vitro Assays, and In Silico GPx Modulation

Abstract

Background: Cordia sinensis Lam. is traditionally employed in the management of oxidative stress and inflammation-associated conditions; however, systematic biochemical and mechanistic evaluation of its stem remains limited. Aim: This study aimed to evaluate the in vitro antioxidant activity of C. sinensis stem extracts and investigate their interaction with human Glutathione Peroxidase (GPx) using molecular docking. Methods: Ethanolic and aqueous stem extracts were prepared and quantitatively analysed for Folin-Ciocalteu and aluminium chloride tests, which were used to determine Total Phenolic Content (TPC) and Total Flavonoid Content (TFC). The in vitro antioxidant activity was evaluated, and molecular docking studies were performed against human glutathione peroxidase (GPx; PDB ID: 2P31) using AutoDock Vina v1.2.0. Results: The aqueous extract showed significantly higher TPC (36.20 ± 0.85 mg GAE/g) and TFC (158.79 ± 1.57 mg CE/g) than the ethanolic extract. Conversely, the ethanolic extract demonstrated superior antioxidant activity, with IC50 values of 6.94 ± 1.41 μg/mL (DPPH) and 7.47 ± 1.08 μg/mL (ABTS), comparable to quercetin. Docking analysis revealed stable binding interactions of major phenolic and flavonoid constituents. For instance, rutin exhibited a docking score of −7.7 kcal/ mol against GPx. Conclusion: The findings demonstrate that C. sinensis stems possess substantial antioxidant potential driven by solvent-dependent phytochemical profiles. Major Findings: The ethanolic extract of C. sinensis demonstrated antioxidant activity with IC50 values of 6.94 ± 1.41 μg/mL (DPPH) and 7.47 ± 1.08 μg/mL (ABTS). Among the evaluated phytoconstituents, rutin exhibited a docking score of −7.7 kcal/mol against GPx