Phytochemical profiling and bioactivity validation of Moringa oleifera leaves: Antimicrobial, antidiarrheal, analgesic, and in silico insights.

The increasing threat of antimicrobial resistance and the need for new medicines have renewed interest in medicinal plants like Moringa oleifera Lam., a fast-growing tree from the Moringaceae family that can survive in dry conditions. It is easily recognized by its compound leaves and long seed pods. Traditionally, it has been widely used in Ayurvedic medicine and as a nutrient-rich food source, with its leaves, pods, and seeds employed for treating malnutrition, inflammation, and over 300 ailments across South Asia and Africa. A methanolic leaf extract was prepared and analyzed via GC-MS/MS for phytoconstituents. Antimicrobial activity was tested against Gram-positive, Gram-negative bacteria, and fungi using disc diffusion (100 µg/disc), compared to standard antibiotics (30 µg/disc). Antidiarrheal (castor oil-induced model) and analgesic (acetic acid-induced writhing) effects were assessed at 200 and 400 mg/kg doses, with Loperamide and Diclofenac as standards, respectively. Molecular docking analyzed interactions of key compounds with therapeutic targets (URO, EGFR, DHFR, etc.). GC-MS/MS revealed 79 bioactive compounds including 4,5-dimethoxy-2-biphenylcarboxylic acid (14.32%), gamma-sitosterol (3.83%) and stigmasterol (0.81%). The extract showed broad-spectrum antibacterial activity, with strongest inhibition against Pseudomonas aeruginosa (19 mm) and Salmonella typhi (19 mm), though 30-50% less potent than standard antibiotics. In antidiarrheal testing, 400 mg/kg dose reduced diarrheal episodes by 58.06% compared to control, while in analgesic assay it decreased writhing by 59.18%. Molecular docking demonstrated superior binding of compounds 57, 65 and 61 to molecular targets, with compound 57 showing strongest affinity to URO (-6.7 kcal/mol) and compound 65 to EGFR (-9.6 kcal/mol). ADME/T analysis revealed compounds C57, C59 and C61 possessed optimal drug-likeness (log P 1.33-3.02), high GI absorption, and no predicted toxicity - contrasting with poorly absorbed compounds (C13, C28; TPSA>150). Moringa oleifera methanolic leaves extract demonstrated broad-spectrum bioactivity, validating its traditional uses. While less potent than synthetic drugs, its multi-target mechanisms and bioactive diversity highlight its potential as an adjunct therapy. Further studies should isolate active compounds and optimize formulations for clinical applications.