Phytochemical Characterization and In-Silico Prediction of Molecular Interactions of Cissus populnea Guill. & Perr. Stem Constituents: Relevance to Male Reproductive Health

Cissus populnea Guill. & Perr. is widely used in ethnomedicine for the management of reproductive disorders; however, its phytochemical composition and potential molecular interactions underlying its biological activity remain incompletely characterized. This study investigated the phytochemical constituents, functional group composition, and predicted molecular interactions of bioactive compounds from the ethanol and ethyl acetate fractions of Cissus populnea Guill. & Perr. stem using spectroscopic, chromatographic, and computational approaches. Fourier-transform infrared (FTIR) spectroscopy revealed functional groups consistent with hydroxyl, carbonyl, and aromatic-containing compounds, including phenolic and flavonoid constituents. High-performance liquid chromatography (HPLC) profiling identified thirteen phytochemical constituents, including caffeic acid, ferulic acid, sinapic acid, diphenyl ether, vanillic acid, quercetin, zeaxanthin, trolox, phenyl ether salicylic acid, nicotine, phenol, and theobromine. Molecular docking analysis was subsequently performed to predict the potential interactions of the identified compounds with sex hormone-binding globulin (SHBG), a protein involved in the regulation of circulating sex steroid bioavailability. The docking analysis revealed varying predicted binding affinities, with quercetin (−9.8 kcal/mol) and trolox (−9.3 kcal/mol) showing the most favorable docking scores. Predicted interactions involved hydrogen bonding, hydrophobic contacts, and π–π interactions within the SHBG binding pocket. These computational findings suggest that some phytochemicals present in Cissus populnea Guill. & Perr. may interact favorably with SHBG and provide hypotheses for further biochemical investigation. However, the predicted interactions were not experimentally validated in the present study.