PROTECTION AGAINST ORGANOPHOSPHATE NEUROTOXINS BY TOBACCO CEMBRANOIDS

描述（由申请人提供）： 这个项目的长期目标是开发一种新的解毒剂来对抗有机磷神经毒素，如梭曼和沙林。对恐怖主义威胁的认识提高，促使制定了防止神经毒素袭击的战略。最有可能被使用的神经毒素是以前曾对军事和平民使用过的有机磷酸盐神经毒素。OP抑制脑和外周神经中的乙酰胆碱酯酶（AChE），引起胆碱能危象，如果不治疗，这种危象是致命的。现在使用的经典解毒剂可以防止广泛的神经损伤，并显着降低死亡率。然而，它们不能靶向由毒性OP引发的神经元凋亡，从而导致长期神经损伤。本研究拟对一种新的神经保护化合物（1 S，2 E，4 R，6 R，7 E，11 E）-cembra-2，7，11-triene-4，6-diol（4 R）进行实验研究。4 R神经保护作用是由体外和体内模型中发现有效的烟碱抗凋亡机制介导的。4 R无毒，具有良好的药理学特性，具有抗凋亡和抗肿瘤特性。由于在解毒剂开发的早期阶段使用战争神经毒素是不切实际的，因此将针对两种毒性较小的类似物对氧磷（POX）和二异丙基氟磷酸盐（DFP）测试4 R的神经保护功效。本文提出的第一个目标是在体外模型中测试4 R对POX和DFP的作用。4 R的体外神经保护活性将单独测试和与经典解毒剂组合测试。用于体外研究的模型是海马切片。将通过电生理学和组织学方法确定毒素造成的损伤。第二个目标将使用大鼠模型在体内解决4 R对两种毒素的功效。将针对不同剂量的POX和DFP测试与经典解毒剂的几种组合中的4 R。将使用行为、生理和组织学测定来确定4 R的功效。在第三个目标中，将研究4 R神经保护的治疗机会窗口与经典解毒剂的各种组合。评估有机磷酸酯和4 R神经保护的毒性作用的变量将如目标2中所述。 从公共卫生的角度来看，在治疗军事或平民人口的有机磷农药中毒方面的任何改进都将在减少人类痛苦和所涉费用方面具有重大价值。接触有机磷农药的风险不仅限于战争或恐怖袭击，还包括工业杀虫剂泄漏、意外中毒和长期职业接触。

DESCRIPTION (provided by applicant): The long term objective of this project is to develop a novel antidote against the organophosphate nerve toxins like soman and sarin. The increased awareness of terrorist threats prompted the development of strategies for protection against nerve toxin attacks. The most likely nerve toxins to be used are the organophosphate (OP) neurotoxins that have been used before against military and civilian populations. OPs inhibit the acetylcholinesterase (AChE) in brain and peripheral nerves, causing a cholinergic crisis that is fatal if untreated. The classic antidotes now in use protect against a wide spectrum of neural injury and dramatically decrease mortality. They fail, however, to target neuronal apoptosis initiated by the toxic OP allowing for long term neurological impairment. Here we propose to test a novel neuroprotective compound the (1S,2E,4R,6R,7E,11E)-cembra-2,7,11-triene-4,6-diol (4R). 4R neuroprotection is mediated by a nicotinic antiapoptotic mechanism found effective in in vitro and in vivo models. 4R is not toxic and has a favorable pharmacological profile with antiapoptotic and antiinflammatory properties. Since the use of war neurotoxins is impractical in the early stages of antidotes development the neuroprotective efficacy of 4R will be tested against two less toxic analogues, paraoxon (POX) and diisopropylfluorophosphate (DFP). The first objective proposed here is to test 4R in an in vitro model against POX and DFP. The in vitro neuroprotective activity of 4R will be tested alone and in combination with the classical antidotes. The model to be used for the in vitro studies is the hippocampal slice. The damage inflicted by the toxins will be determined by electrophysiological and histological methods. The second aim will address the efficacy of 4R against both toxins in vivo using a rat model. 4R in several combinations with classical antidotes will be tested against various doses of POX and DFP. Behavioral, physiological, and histological determinations will be used to determine the efficacy of 4R. In the third aim the window of therapeutical opportunity for 4R neuroprotection will be investigated in various combinations with the classical antidotes. The variables to asses the toxic effect of the organophosphates and of 4R neuroprotection will be as in aim 2. From the public health perspective any improvement in the treatment of OPs poisoning of military or civilian population would be of great value in human suffering and costs involved. The risk of OPs exposure is not restricted to war scenario or terrorist attacks but includes industrial leaks of insecticides, accidental poisonings and chronic occupational exposure.