Cross-Reactivity and Neutralization Capacity of Polyspecific Antivenom Produced by Razi Institute against Three Species of Buthidea Family Scorpions

Scorpion sting is a significant health problem in southern provinces of Iran. Many thousands of people are stung by different species of scorpions annually. More than 60 scorpion species have been reported to be present in Iran. However, Razi Institute manufactures polyvalent antivenom against only six species of scorpions, excluding Buthacus macrocentrus, Apistobuthus susanae and Vachoniolus iranus, wide spread scorpion species in the south region of Iran. Since the venom of these scorpion species is not included in the production of Razi polyvalent antivenom, the aim of this study was to check the neutralization capacity of our antivenom against these species.  

In this research, after collecting scorpions (at night), milking by the electroshock method, the venom was lyophilized and the LD50 was determined. The fractions were then separated by gel chromatography and HPLC. Using SDS page electrophoresis, the fractional molecular weight was determined. At the end, the potency test of these scorpion venoms was carried out in the vicinity of the antiserum produced by Razi Institute on the animal. In the present work, we tried to investigate the cross reactivity of present antivenom against these excluded scorpion species.

The antisera production of Razi Institute was able to neutralize the 33 LD50 of Apistobuthus susanae venom.This antivenom could neutralize Buthacus macrocentrus as well as Vachoniolus iranus scorpion venoms by 41 LD50 and 15 LD50, respectively.

Based on the results obtained in the present study that indicate the neutralization of the three species of scorpions’ venom, not included in antivenom production, the present Razi polyvalent antivenom is able to be used in patients stung by these 3 species of scorpions.