Abstract
<title>Abstract</title> <p> Background Snakebite envenomation remains a major public health challenge, particularly in low- and middle-income countries where access to safe, effective, and affordable antivenoms is limited. Medicinal plants are an important source of bioactive compounds with potential antivenom properties. This study investigated the phytochemical profile and <italic>in vivo</italic> antivenom efficacy of the ethanolic leaf extract of <italic>Solanecio mannii</italic> against <italic>Bitis arietans</italic> venom in female Swiss albino mice. Methods Fresh leaves of <italic>S. mannii</italic> were extracted using ethanol, and the phytochemical composition was characterized by gas chromatography–mass spectrometry (GC–MS). <italic>In vivo</italic> antivenom efficacy was evaluated in female Swiss albino mice experimentally envenomed with <italic>B. arietans</italic> venom. Following determination of venom lethality (LD₅₀ = 175 mg/kg), a challenge dose equivalent to 2LD₅₀ (350 mg/kg body weight) was pre-incubated with ethanolic leaf extract concentrations of 200, 400, 600, 800, and 1000 ppm before administration. Survival outcomes were analyzed using probit regression, with statistical significance set at <italic>p</italic> < 0.05. Results GC–MS analysis identified 14 phytochemical constituents, with 2-methoxy-4-(prop-2-en-1-yl)phenol as the predominant compound, accounting for 16.8% of the total chromatographic peak area. The extract comprised phenolic compounds, flavonoids, terpenoids, benzopyrones, aldehydes, and diterpene alcohols. The venom-only group exhibited 0% survival, whereas the normal saline control group achieved 100% survival. Treatment with the extract produced a concentration-dependent increase in survival from 20% at 200 ppm to 60% at 400 ppm and 80% at 600, 800, and 1000 ppm. Probit regression demonstrated a significant antivenom effect ( <italic>p</italic> = 0.024), with an estimated ED₅₀ of 452.40 ppm (95% fiducial confidence limits: 97.26–852.92 ppm). Conclusion The ethanolic leaf extract of <italic>Solanecio mannii</italic> demonstrated significant concentration-dependent <italic>in vivo</italic> antivenom activity against <italic>Bitis arietans</italic> venom. These findings support its ethnomedicinal use in snakebite management and provide a basis for further studies to isolate the active constituents, elucidate their mechanisms of action, and evaluate their therapeutic potential. </p>