Efficacy of anti-scorpion venom serum over prazosin in severe scorpion envenomation: Is the current evidence enough?

Scorpion anti-venom activity of botanicals: a pharmacological approach

Scorpion bite is considered as one of the common and dangerous phenomenon throughout the world. The clinical manifestations include pulmonary edema, myocardial damage, intracerebral haemorrhage, brachial plexopathy, renal failure etc. which sometimes leads to mortality. The common antivenin therapy includes anti-scorpion venom serum or prazosin. In the vast rural areas of the third world countries phytotherapy is considered as an alternative system of medicine and scorpion sting is treated with the help of medicinal botanicals. As the safety and efficacy are considered as important aspects of anti venin therapy, conventional treatment can be supported by the herbal remedy. The present review compiles a number of medicinal plants pharmacologically evaluated in vitro and/or in vivo for scorpion antivenin properties. Considering the aspects like cost effectiveness, availability, lesser side effects and development of drug resistance, plant based anti venin therapy may be considered as a possible remedy against scorpion envenomation.

Evaluation of three different formats of a neutralizing single chain human antibody against toxin Cn2: neutralization capacity versus thermodynamic stability

The single-chain antibody fragment (scFv) 6009F, obtained by directed evolution, neutralizes the effects of the Cn2 toxin, which is the major toxic component of Centruroides noxius scorpion venom. In this work we compared the neutralization capacity and the thermodynamic stability of scFv 6009F with those of two other derived formats: Fab 6009F and diabody 6009F. Additionally, the affinity constants to Cn2 toxin of the three recombinant antibody fragments were determined by means of BIAcore. We found a correlation between the thermodynamic stability of these antibody fragments with their neutralization capacity. The order of thermodynamic stability determined was Fab≫scFv>diabody. The Fab and scFv were capable of neutralizing the toxic effects of Cn2 and whole venom but the diabody was unable to fully neutralize intoxication. In silico analysis of the diabody format indicates that the reduction of stability and neutralization capacity could be explained by a less cooperative interface between the heavy and the light variable domains.