Insight into the toxicological and pathophysiological effects of Moroccan vipers' venom: Assessing the efficacy of commercial antivenom for neutralization

• Published in: Tropical medicine and infectious disease 2023-05, Vol.8 (6), p.1-21
• Main Authors: Khourcha, Soukaina, Hilal, Ines, Elbejjaj, Iatimad, Karkouri, Mehdi, Safi, Amal, Hmyene, Abdelaziz, Oukkache, Naoual
• Format: Article
• Language: English
• Subjects: Analysis; Animals; Antivenins; antivenom; Biological products; Bites and stings; Bitis arietans; Cerastes cerastes; Daboia mauritanica; Edema; Enzymes; Histology, Pathological; Mortality; Physiology; Physiology, Pathological; physiopathology; Poisonous snakes; Proteins; Skin; Snake bites; Snakebites; toxic activities; Treatment; Venom
• ISSN: 2414-6366; 2414-6366
• DOI: 10.3390/tropicalmed8060302

Morocco is one of the richest countries in biodiversity in the Mediterranean region, especially in its ophidian fauna. In total, there are eight species of venomous snakes, with seven belonging to the Viperidae family, responsible for 67.2% of severe envenomation cases in the country. 'Cerastes cerastes', 'Daboia mauritanica' and 'Bitis arietans' are considered among the most venomous vipers whose bites cause high levels of morbidity, disability or mortality. Despite their wide distribution in the kingdom, the incidence of these snakebites remains poorly understood and largely underestimated. Moreover, intraspecific variations in the venom composition significantly affect the effectiveness of antivenoms. Due to the unavailability of locally produced antivenoms, we evaluated the efficacy of 'Inoserp-MENA', the only available antivenom in Morocco, against 'C. cerastes', 'D. mauritanica' and 'B. arietans'. First, we conducted a comprehensive characterization of these venoms, including an LD50 test to examine their toxicity and SDS-PAGE as a technique to analyze the enzymes responsible for biological activities, such as hemorrhagic and edematous activities and myotoxicity, which generate physiopathological effects in the skin, paws and muscles of envenomed mice. Then, we assessed the ability of Inoserp-MENA antivenom to neutralize the toxic activities of Moroccan vipers. Our results indicate that the venom of 'C. cerastes', 'D. mauritanica' and 'B. arietans' are toxic, causing severe alterations such as edema, myotoxicity, myonecrosis and significant hemorrhages with the formation of hemorrhagic foci. 'C. cerastes' venom is more dangerous in terms of lethality and hemorrhages, while 'B. arietans' venom is more edematous. The effects of 'C. cerastes' venom were effectively neutralized, but 'Inoserp-MENA' antivenom failed to protect mice against the toxic effects induced by 'B. arietans' and 'D. mauritanica' venom. The study reveals alarming shortcomings in the effectiveness of the current commercially available antivenom's dosage and neutralization capabilities, highlighting the urgent need to develop a region-specific viper envenomation therapy.