Zhou Jing, Zhao Huacong, Chen Luyao, Xing Xiaowei, Lv Tingmei, Yang Xinyi, Wu Qinan, Duan Jinao, Ma Hongyue
Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, Jiangsu Key Laboratory for High Technology Research of TCM Formulae, College of Pharmacy, Nanjing University of Chinese Medicine Nanjing 210023 China
RSC Adv. 2019 Jan 9;9(3):1208-1213. doi: 10.1039/c8ra07871h.
The population of Cantor in China has been alarmingly declining due to environmental pollution. Deltamethrin is a pyrethroid pesticide frequently used in agriculture and much of its residues are present in crops, soil and water. Deltamethrin has been shown to have toxicity to toads. Herein, we assumed that deltamethrin contamination might influence the biosynthesis of toxic substances present in toad venom. Bufadienolides present in venom are the toad's chemical defense and highly toxic to predators, and they are important for the survival of toad species against predators. In this study, we determined the contents of bufadienolides in toad venom using a HPLC-triple quadrupole mass spectrometer to evaluate the change in bufadienolide profiles in toad venom before and after cutaneous exposure to deltamethrin. The results indicated that toads exposed to high concentration of deltamethrin survive the least, do not exuviate, and their movements are stiff. Furthermore, it was observed that high level of deltamethrin contamination induces a marked decrease in the levels of toxic bufadienolides in toad venom. These changes in the toxin profiles could lead to the compromised chemical defense of toad, leading to more susceptible to attack by predators. This is the first study to report that environmental contaminants (pesticides) can influence the toad's toxic profiles, suggesting one factor contributing to the decline in the population of Cantor.
由于环境污染，中国的黑眶蟾蜍种群数量一直在惊人地下降。溴氰菊酯是一种常用于农业的拟除虫菊酯类杀虫剂，其大量残留物存在于农作物、土壤和水中。已证明溴氰菊酯对蟾蜍有毒性。在此，我们假设溴氰菊酯污染可能会影响蟾蜍毒液中有毒物质的生物合成。毒液中的蟾蜍二烯羟酸内酯是蟾蜍的化学防御物质，对捕食者具有高毒性，它们对于蟾蜍物种抵御捕食者的生存至关重要。在本研究中，我们使用高效液相色谱 - 三重四极杆质谱仪测定蟾蜍毒液中蟾蜍二烯羟酸内酯的含量，以评估皮肤暴露于溴氰菊酯前后蟾蜍毒液中蟾蜍二烯羟酸内酯谱的变化。结果表明，暴露于高浓度溴氰菊酯的蟾蜍存活率最低，不蜕皮，且行动僵硬。此外，观察到高水平的溴氰菊酯污染会导致蟾蜍毒液中有毒蟾蜍二烯羟酸内酯的含量显著降低。这些毒素谱的变化可能导致蟾蜍的化学防御能力受损，使其更容易受到捕食者的攻击。这是第一项报道环境污染物（农药）会影响蟾蜍毒素谱的研究，表明这是导致黑眶蟾蜍种群数量下降的一个因素。
