Antioxidant and Metabolomic Profile of <i>Psychotria adenophylla</i>: Green Synthesis of AgO Nanoparticles With Anti‐Inflammatory, Antidiabetic, Antibacterial Activities

Psychotria adenophylla Wall. (Rubiaceae) is a promising plant with potential drug molecules. In this study, ethanolic leaf extracts were utilized for antioxidant (DPPH, FRAP, and H₂O₂ methods) and metabolomic (GC-MS and FTIR) and potential, evaluation, synthesis, and characterization of nanoparticles (PAE AgO NPs) using UV-visible, FTIR, XRD, SEM, FESEM-EDX, and dynamic light scattering (DLS) with zeta potential. The study also assessed the anti-inflammatory, antidiabetic, and antibacterial activities of the extracts and nanoparticles. GC-MS analysis identified 30 distinct secondary metabolites. Among the tested solvents, the ethanolic crude extract demonstrated the highest antioxidant capacity, with the lowest IC₅₀ value compared to petroleum ether, chloroform, and aqueous extracts. Characterization of AgO NPs revealed a tetragonal crystalline structure with an average size of 13.66 nm. AgO NPs exhibited notable anti-inflammatory and antidiabetic activities. Furthermore, ethanolic crude extracts (75-300 µg/mL) and AgO NPs (37.5-150 µg/mL) significantly inhibited the growth of Klebsiella pneumoniae, Citrobacter sp., Salmonella typhi, Bacillus subtilis, and Enterococcus faecalis. The antibacterial activity was quantified using minimum bactericidal concentrations (MBCs) and minimum inhibitory concentrations (MICs). Compared to crude extracts, the green-synthesized AgO NPs from ethanolic extracts demonstrated superior antibacterial efficacy, with larger zones of inhibition and lower MIC and MBC values.