Rankovic G, Stankovic V, Zivkovic M, Rankovic B, Laketic D, Potic M, Saranovic M, Rankovic G Nedin
Bratisl Lek Listy. 2019;120(8):576-580. doi: 10.4149/BLL_2019_094.
Quinine, a frequently used anti-malaria alkaloid isolated from the Cinchona bark, possesses numerous toxic properties, the majority of which arrive from a dysfunction of the gastrointestinal tract. Similarly, cinchonine, another alkaloid from the Cinchona bark, displays a great potential for treating malaria (especially the resistant forms).
In this work, we aimed to evaluate the effects of cinchonine on spontaneous and induced Wistar rat ileum contractions in order to uncover potential side effects that might arise after its application.
Cinchonine produced a concentration-dependent spasmolytic activity, which was found to be reversible (i.e. disappeared after tissue wash-up), with an IC50 value of 273 µM. Furthermore, the mechanism of action of cinchonine at IC50 elucidated through experiments with acetylcholine and Ca2+-induced ileum contractions. The applied IC50 concentration of cinchonine statistically significantly prevented the occurrence of contractions after the application of specific agonist. The obtained results are in a range with the effects seen with standard receptor antagonists, i.e. atropine and verapamil.
The obtained results showed that cinchonine inhibited both types of induced contractions, suggesting a Ca2+-channels mediated modus operandi (Fig. 4, Ref. 19).
奎宁是一种从金鸡纳树皮中分离出来的常用抗疟生物碱，具有多种毒性特性，其中大部分源于胃肠道功能紊乱。同样，金鸡纳碱是金鸡纳树皮中的另一种生物碱，具有治疗疟疾（尤其是耐药形式）的巨大潜力。
在这项研究中，我们旨在评估金鸡纳碱对Wistar大鼠回肠自发收缩和诱导收缩的影响，以发现其应用后可能出现的潜在副作用。
金鸡纳碱产生浓度依赖性解痉活性，发现该活性是可逆的（即组织冲洗后消失），IC50值为273μM。此外，通过乙酰胆碱和钙离子诱导的回肠收缩实验阐明了金鸡纳碱在IC50时的作用机制。应用的金鸡纳碱IC50浓度在统计学上显著阻止了特定激动剂应用后收缩的发生。所得结果与标准受体拮抗剂（即阿托品和维拉帕米）的作用效果范围一致。
所得结果表明，金鸡纳碱抑制了两种类型的诱导收缩，提示其作用方式为钙离子通道介导（图4，参考文献19）。
