Development and Comparative Evaluation of Antivenoms Targeting the Pathophysiological Effects of Scorpion Venom Toxins in North Africa

Introduction:

Scorpion envenomation is a major public health concern in North Africa, with Androctonus mauretanicus (Am), Androctonus australis hector (Aah), and Buthus occitanus (Bo) causing severe and often fatal cases. Am is the most dangerous and endemic species in Morocco. Due to the limited availability of effective antivenoms, treatment remains largely symptomatic. Understanding the pathophysiological mechanisms of venom action and improving therapeutic strategies are essential. This study aims to address this gap by developing and evaluating antivenoms targeting the main toxins involved in North African envenomations.

Methods:

The monovalent antivenom was produced by immunizing albino rabbits with Am venom collected from high-risk Moroccan regions. Neutralization potency was assessed in vivo using Swiss mice through LD₅₀ and ED₅₀ determinations. Histological and immunohistochemical analyses were conducted on vital organs (brain, heart, liver, lungs, kidneys) following administration of sublethal doses of Am, Aah, and Bo venoms. Both antivenoms (monovalent and Mexican polyvalent) were tested under similar conditions.

Results:

The Moroccan monovalent antivenom demonstrated strong specificity against Am and effective cross-neutralization of Aah and Bo venoms. Interestingly, while it showed superior efficacy against Am, the Mexican polyvalent antivenom was more effective in neutralizing the tissue damage induced by Bo and Aah. Histological evaluations confirmed a reduction in venom-induced lesions, particularly in cardiac and hepatic tissues, following antivenom administration four hours post-envenomation.

Conclusion:

This study underscores the critical role of antivenom as a specific and effective therapeutic tool in managing scorpion envenomations. The development of targeted antivenoms adapted to regional venom profiles enhances treatment outcomes and offers a promising path forward in combating scorpionism in Morocco and North Africa.