National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS 38677, USA; Divison of Pharmacognosy, Department of BioMolecular Sciences, The University of Mississippi, University, MS 38677, USA.
National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS 38677, USA.
J Ethnopharmacol. 2017 Feb 2;197:211-217. doi: 10.1016/j.jep.2016.07.069. Epub 2016 Jul 26.
Ayurveda, an ancient holistic system of health care practiced on the Indian subcontinent, utilizes a number of multi-plant formulations and is considered by many as a potential source for novel treatments, as well as the identification of new drugs. Our aim is to identify novel phytochemicals for the inhibition of bacterial exotoxin, botulinum neurotoxin A (BoNT/A) based on Ayurvedic literature. BoNT/A is released by Clostridium species, which when ingested, inhibits the release of acetylcholine by concentrating at the neuromuscular junction and causes flaccid paralysis, resulting in a condition termed as botulism, and may also lead to death due to respiratory arrest.
Fifteen plants were selected from the book 'Diagnosis and treatment of diseases in Ayurveda' by Vaidya Bhagwan Dash and Lalitesh Kashyap, based on their frequency of use in the formulations used for the treatment of six diseases with neuromuscular symptoms similar to botulism. Phytochemicals from these plants were screened using in silico, and in vitro methods. Structures of 570 reported phytochemicals from 14 plants were docked inside six reported BoNT/A light chain crystal structures using ensemble docking module in Maestro (Schrödinger, LLE).
From the docking scores and structural diversity, nine compounds including acoric acid 1, three flavonoids, three coumarins derivatives, one kava lactone were selected and screened using an in vitro HPLC-based protease assay. The bioassay results showed that several compounds possess BoNT/A LC inhibition of 50-60% when compared to positive controls NSC 84094 and CB7967495 (80-95%).
Further testing of the active compounds identified from Ayurvedic literature and structure-activity studies of acoric acid 1 using more sensitive bioassays is under way. The identification of acoric acid 1, a novel scaffold against BoNT/A, exemplifies the utility of Ayurvedic literature for the discovery of novel drug leads.
阿育吠陀是一种古老的整体医疗体系，在印度次大陆得到广泛应用，它采用了多种多植物配方，被许多人认为是新型治疗方法的潜在来源，也是新药物的发现来源。我们的目标是根据阿育吠陀文献，寻找新型植物化学物质来抑制细菌外毒素肉毒神经毒素 A（BoNT/A）。BoNT/A 由梭菌属释放，当被摄入时，它会通过集中在运动神经元连接处来抑制乙酰胆碱的释放，导致肌肉无力麻痹，从而导致一种称为肉毒中毒的疾病，并且还可能因呼吸停止而导致死亡。
根据 Vaidya Bhagwan Dash 和 Lalitesh Kashyap 所著的《阿育吠陀疾病的诊断与治疗》一书中用于治疗六种具有类似肉毒中毒的神经肌肉症状的疾病的配方中使用的频率，从书中选择了 15 种植物。使用基于计算机的方法和体外方法筛选这些植物的植物化学物质。使用 Maestro（Schrödinger，LLE）中的整体对接模块将来自 14 种植物的 570 种报告的植物化学物质结构对接入六种报告的 BoNT/A 轻链晶体结构中。
根据对接得分和结构多样性，选择了包括阿科酸 1、三种类黄酮、三种香豆素衍生物、一种卡瓦内酯在内的 9 种化合物，并使用基于 HPLC 的体外蛋白酶测定法进行了筛选。生物测定结果表明，与阳性对照物 NSC 84094 和 CB7967495（80-95%）相比，几种化合物对 BoNT/A LC 的抑制率为 50-60%。
正在对从阿育吠陀文献中鉴定出的活性化合物进行进一步测试，并使用更灵敏的生物测定法对阿科酸 1 进行结构活性研究。鉴定出阿科酸 1 是一种针对 BoNT/A 的新型支架，这证明了阿育吠陀文献在发现新型药物先导物方面的实用性。
