Neutralization Capacity of Tissue Alterations Caused by the Venoms of the Most Dangerous Scorpions in North Africa Using a Selective Antivenom

Abstract

In North Africa, scorpion stings pose an urgent public health problem, particularly for children with high morbidity and mortality rates. The main species implicated are the Androctonus mauretanicus (Am), Androctonus australis hector (Aah), and Buthus occitanus (Bo). Immunotherapy is the specific therapeutic approach aimed at directly neutralizing toxins, despite their severity and rapid diffusion. In the present study, we evaluate, histologically and immunohistologically, the neutralization potency of the selective antivenom produced against, among other species, the Am, Aah, and Bo at the level of the tissue alterations in Swiss mice, as experimental subjects. Firstly, the lethal doses 50 test was conducted to assess the venom’s toxic activity, and then the median effective dose of the antivenom was determined against each venom. The histological and immunohistological analyses were performed by injecting the sublethal dose of venom, the complex venom and antivenom, or the antivenom 2 h following inoculation of venom. Our study revealed the highest toxicity of the Am, followed by the Aah and then the Bo venom. The neutralizing ability and effectiveness of the antivenom to completely or partially neutralize the tissular damages were demonstrated in all organs studied: brain, heart, lungs, liver, and kidneys. Our results highlighted the important cytoplasmic and membranous staining in the heart compared to the brain tissue for the three scorpion venoms. Therefore, the scorpionic antivenoms are able to reach their target even at the tissue level. Immunotherapy represents the specific and recommended treatment against the scorpionic stings in North Africa.

Development and Efficacy of the Antivenom Specific to Severe Envenomations in Morocco and North Africa: Advancements in Scorpion Envenomation Management

“…The neutralizing effects of the antivenom reveled in these results align with numerous studies [31][32][33][34][35]. In a previous study carried out by our team, we demonstrated the effectiveness of a selective polyvalent antivenom in completely or partially neutralizing the histological alterations induced by Am, Aah, and Bo scorpion venoms in the main organs of mice [36]. However, for comparison purposes, the produced serum exhibited a high capacity for neutralization, especially for the venom produced against it (Am) compared to the selective polyvalent antivenom manufactured against various species of scorpions, including the Am venom [36].…”

“…The lyophilized form of the Androctonus australis hector (Aah) Tunisian scorpion venom was generously provided by ATheris Laboratories. Their median lethal dose (LD 50 ) and sublethal dose (sLD) were defined, respectively, as 890.1 and 415 µg/kg for the Bo venom and 597 and 255 µg/kg for the Aah venom [36].…”

“…The brain and heart tissue sections were removed from paraffin and cycles of rehydration were executed for 5 min each using the xylol and alcohol series. The protocol of the immunohistological study was previously described for the both organs obtained from the control group, who were treated only with the scorpion venom, and the other group, who were treated with the antivenom 2 h following the injection of venom [36].…”