<![CDATA[Background: Tuberculosis (TB) remains a major global health challenge due to the emergence of drug-resistant strains and the limited availability of novel antitubercular agents. Natural products have gained increasing attention as potential sources of antimycobacterial compounds. Flemingia strobilifera is known to contain diverse bioactive metabolites that may exhibit inhibitory activity against mycobacterial targets. Objective: This study aimed to evaluate the antimycobacterial potential of Otok-otok (Flemingia strobilifera) leaf extract through integrated in silico and in vitro approaches. Methods: Five dominant metabolites of F. strobilifera, namely Octylimino dipropan-2-ol, 3,12-diketo-4,6-petromyzonene-24-sulfate, Kaempferol-3-O-rutinoside, Adenosine, and Flavonol 3-O-D-xylosylglucoside, were subjected to molecular docking against InhA (enoyl-acyl carrier protein reductase), a key enzyme involved in mycolic acid biosynthesis. Docking simulations were performed using AutoDock4 following validation through native ligand redocking. In vitro antimycobacterial activity was evaluated against Mycobacterium smegmatis using aqueous, ethanolic, and methanolic leaf extracts at concentrations ranging from 6.25 to 200 mg/mL, with activity assessed by measuring inhibition zone diameters. Results: Molecular docking revealed that 3,12-diketo-4,6-petromyzonene-24-sulfate exhibited the strongest binding affinity toward InhA with a binding energy of –8.90 kcal/mol, followed by Flavonol 3-O-D-xylosylglucoside (–8.05 kcal/mol). The latter also formed multiple hydrogen bonds with key active-site residues, including Tyr158, Lys165, and Met199. In vitro evaluation demonstrated concentration-dependent antimycobacterial activity for all extracts. Methanolic extract showed the highest activity, producing inhibition zones ranging from 8.14 ± 0.42 mm to 23.08 ± 0.88 mm, followed by ethanolic extract (7.36 ± 0.38–20.54 ± 0.77 mm) and aqueous extract (5.24 ± 0.31–14.28 ± 0.74 mm). No inhibition was observed in the negative control, while streptomycin sulfate exhibited the highest inhibitory effect. Conclusion: The findings indicate that Flemingia strobilifera possesses promising antimycobacterial potential. The strong affinity of selected metabolites toward InhA and the concentration-dependent inhibitory activity of leaf extracts against M. smegmatis suggest that this plant may serve as a potential source of antitubercular candidates. Further in vivo studies and mechanistic investigations are required to validate its therapeutic potential.]]>
