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United States Department of Agriculture

Agricultural Research Service

Research Project: MOLECULAR AND GENETIC MECHANISMS OF HESSIAN FLY RESISTANCE IN SOFT WINTER WHEAT Title: Neurotoxic and Cytotoxic Effects of Venom from Different Populations of the Egyptian Scorpio Maurus Palmatus

Authors
item Abdel-Rahman, Mohamed -
item Omran, Mohamed Alaa -
item Abdel-Nabi, Ismail -
item Nassier, Omimah -
item Schemerhorn, Brandon

Submitted to: Toxicon
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 13, 2009
Publication Date: March 15, 2010
Citation: Abdel-Rahman, M.A., Omran, M.A., Abdel-Nabi, I.M., Nassier, O.A., Schemerhorn, B.J. 2010. Neurotoxic and Cytotoxic Effects of Venom from Different Populations of the Egyptian Scorpio Maurus Palmatus. Toxicon. 55:298-306.

Interpretive Summary: Scorpio maurus palmatus belongs to the family Scorpionidae and is found in the Coastal Plain of Libyan Desert, Lower Egypt, Southern and Central Sinai. Each scorpion lives alone in a burrow, but hundreds of burrows may be found in some areas. The scorpion S.m. palmatus was chosen for a study on neurotoxic and cytotoxic effects of venom because of the unique structure of its venom. Previously, we have found that scorpion venom of the Egyptian S. m. palmatus collected from different biotopes had different properties that were sex dependent. The main goal of this work is to examine and estimate the neurotoxic and cytotoxic effects of S. m. palmatus venom collected from different locations in Egypt and to assess whether the pharmacological properties of the venom taken from these different populations vary with geographic location, as well as to evaluate the insecticidal potency of this specific venom. This study found that this species of scorpion has venom with significant neurotoxic and cytotoxic effects on insect cells & has potential for being developed into an environmentally friendly bioinsecticide. The resulting data identified a potential target for those developing environmentally friendly bioinsecticides, and will impact future development in these areas.

Technical Abstract: Neurotoxic and cytotoxic effects of venoms from Scorpio maurus palmatus taken from different populations were assessed for geographic based variability in toxicity and to evaluate their insecticidal potency. Scorpions were collected from four regions. Three locations were mutually isolated pockets in the arid area of Southern Sinai. The fourth sample was collected from a population inhabiting the semi-arid environment of Western Mediterranean Coastal Desert. The neurotoxic (paralytic) effect of the venom from each population was assayed by its ability to induce permanent disability in adult cockroaches within 3 hours. Venom was applied using microinjection techniques through an intersegmental membrane. Probit analysis was used to calculate the Paralytic Effective Dose (PED50, ng/100mg). Levels of glutathione, lipid peroxidation, protein carbonyl content and nitric oxide, as well as the activities of superoxide dismutase, catalase and cholinesterase, were measured to assess the cytotoxicity of the venom. The results show that the injected venom from each population induced obvious spasticity, followed by flaccid paralysis. All the tested biochemical parameters, except glutathione content, revealed significant differences in toxicity in venom taken from the different scorpion populations. We conclude that (i) the venom of this scorpion has significant neurotoxic and cytotoxic effects on insect cells, (ii) its efficacy, as assessed by the PED50 unit, exhibited variation across its geographic range and (iii) components in the venom may have the potential for being developed into effective and friendly environmental bioinsecticides.

Last Modified: 10/25/2014