Phytochemical Profiling and Investigation of Analgesic, Anti-Diarrheal, and CNS Depressant Activity of Leea Macrophylla (Roxb.) Extract Using Experimental and Computational Approaches

Leea macrophylla is used in traditional medicine in Bangladesh, yet its whole plant has been little examined for analgesic, antidiarrheal and central nervous system (CNS) effects. A methanolic whole-plant extract (MELM) was profiled by gas chromatography–mass spectrometry (GC–MS). Male Swiss albino mice received MELM (200, 400 and 600 mg/kg) in tail-flick, formalin-induced paw-licking and biting, castor oil-induced diarrhea and phenobarbitone-induced sleep tests. Identified compounds were docked to the μ-opioid receptor, cyclooxygenase-2 (COX-2), M3 muscarinic receptor and GABA_A receptor and screened by ADMET (absorption, distribution, metabolism, excretion, toxicity) prediction. GC–MS identified 67 compounds, chiefly fatty acid derivatives and phytol. MELM increased tail-flick latency in a dose- and time-dependent manner and reduced formalin-induced licking and biting by up to 74.19% (600 mg/kg). Fecal output fell by 82.24% at 200 mg/kg, with weaker effects at higher doses. MELM shortened phenobarbitone-induced sleep, significantly at 200 and 400 mg/kg, which does not indicate CNS depression. Campesterol and lanosterol ranked among the top-scoring compounds for several targets and met all ADMET criteria. MELM shows analgesic activity in mice and these sterols warrant further experimental validation.