Julianti Tasqiah, De Mieri Maria, Zimmermann Stefanie, Ebrahimi Samad N, Kaiser Marcel, Neuburger Markus, Raith Melanie, Brun Reto, Hamburger Matthias
Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, Basel 4056, Switzerland; Faculty of Pharmacy, Pancasila University, Jakarta 12640, Indonesia.
Division of Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, Basel 4056, Switzerland.
J Ethnopharmacol. 2014 Aug 8;155(1):426-34. doi: 10.1016/j.jep.2014.05.050. Epub 2014 Jun 2.
Leaf decoctions of Carica papaya have been traditionally used in some parts of Indonesia to treat and prevent malaria. Leaf extracts and fraction have been previously shown to possess antiplasmodial activity in vitro and in vivo.
Antiplasmodial activity of extracts was confirmed and the active fractions in the extract were identified by HPLC-based activity profiling, a gradient HPLC fractionation of a single injection of the extract, followed by offline bioassay of the obtained microfractions. For preparative isolation of compounds, an alkaloidal fraction was obtained via adsorption on cationic ion exchange resin. Active compounds were purified by HPLC-MS and MPLC-ELSD. Structures were established by HR-ESI-MS and NMR spectroscopy. For compounds 5 and 7 absolute configuration was confirmed by comparison of experimental and calculated electronic circular dichroism (ECD) spectroscopy data, and by X-ray crystallography. Compounds were tested for bioactivity in vitro against four parasites (Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum), and in the Plasmodium berghei mouse model.
Profiling indicated flavonoids and alkaloids in the active time windows. A total of nine compounds were isolated. Four were known flavonols--manghaslin, clitorin, rutin, and nicotiflorin. Five compounds isolated from the alkaloidal fraction were piperidine alkaloids. Compounds 5 and 6 were inactive carpamic acid and methyl carpamate, while three alkaloids 7-9 showed high antiplasmodial activity and low cytotoxicity. When tested in the Plasmodium berghei mouse model, carpaine (7) did not increase the survival time of animals.
The antiplasmodial activity of papaya leaves could be linked to alkaloids. Among these, carpaine was highly active and selective in vitro. The high in vitro activity could not be substantiated with the in vivo murine model. Further investigations are needed to clarify the divergence between our negative in vivo results for carpaine, and previous reports of in vivo activity with papaya leaf extracts.
在印度尼西亚的一些地区，传统上使用番木瓜叶煎剂来治疗和预防疟疾。叶提取物和馏分先前已显示在体外和体内具有抗疟原虫活性。
通过基于HPLC的活性图谱分析来确认提取物的抗疟原虫活性，并鉴定提取物中的活性馏分，即对提取物进行单次进样的梯度HPLC分级分离，然后对获得的微馏分进行离线生物测定。为了制备性分离化合物，通过阳离子交换树脂吸附获得生物碱馏分。活性化合物通过HPLC-MS和MPLC-ELSD进行纯化。通过HR-ESI-MS和NMR光谱确定结构。对于化合物5和7，通过比较实验和计算的电子圆二色（ECD）光谱数据以及X射线晶体学来确认绝对构型。测试化合物在体外对四种寄生虫（布氏罗得西亚锥虫、克氏锥虫、杜氏利什曼原虫和恶性疟原虫）以及伯氏疟原虫小鼠模型的生物活性。
图谱分析表明在活性时间窗口中存在黄酮类化合物和生物碱。总共分离出九种化合物。四种是已知的黄酮醇——芒果苷、阴香苷、芦丁和烟花苷。从生物碱馏分中分离出的五种化合物是哌啶生物碱。化合物5和6是无活性的卡帕酸和甲基卡巴酯，而三种生物碱7-9显示出高抗疟原虫活性和低细胞毒性。在伯氏疟原虫小鼠模型中进行测试时，番木瓜碱（7）并未延长动物的存活时间。
番木瓜叶的抗疟原虫活性可能与生物碱有关。其中，番木瓜碱在体外具有高活性和选择性。体内小鼠模型未能证实其在体外的高活性。需要进一步研究以阐明我们关于番木瓜碱的体内阴性结果与先前关于番木瓜叶提取物体内活性的报道之间的差异。
