Indian lone commercial antivenom against Indian red scorpion venom demonstrates limited immunorecognition and partial neutralisation of enzymatic, pharmacological, and some toxic effects of Heterometrus bengalensis (Indian black scorpion) venom proteins in vitro and in vivo.

Scorpion envenomation remains a significant yet under-addressed public health issue in India. Heterometrus bengalensis (HB), a medically important scorpion, can induce clinically relevant local and systemic toxicity. However, limited research has evaluated the immunological recognition and neutralisation efficacy of existing commercial anti-scorpion antivenoms (ASV) against HB venom (HBV). This study evaluated the immunological cross-reactivity and neutralisation potential of a commercial ASV against HBV using in vitro and in vivo approaches. Immunochemical assays (enzyme-linked immunosorbent assay and Western blotting) demonstrated partial immunoreactivity toward HBV proteins in the range of ~75-37 kDa, but exhibited poor recognition of low-molecular-mass proteins (<20 kDa). ASV showed feeble neutralisation of HBV enzymatic activities, HBV toxicity, and reactive oxygen species (ROS) production in Caenorhabditis elegans. ASV also showed poor protective efficacy against HBV-induced local and systemic toxicity in Swiss albino mice. ASV also failed to attenuate the HBV-induced production of proinflammatory cytokines (IL-1β, IL-6, and TNF-α) in mice. Therefore, this study highlights insufficient immunological coverage and underscores the need for species-specific antivenoms. The findings provide crucial insights for enhancing therapeutic interventions for scorpion envenomation in India.