Purpose

In the present perspective, emergence of resistant strains of Leishmania donovani and severe side effects resulting from the use of conventional anti-leishmanial therapies present an urgent need for developing novel agents against this parasite. We have explored the effectiveness of secondary plant metabolites as alternative choices in the treatment for visceral leishmaniasis (vl).

Methods

The plant Parthenium hysterophorus L. (Asteraceae) was collected from the West Bengal State University Campus, Barasat, West Bengal, India. The leaves of this plant were extracted by different solvents, such as ethyl acetate, water, petroleum ether and hexane. Gas chromatography–mass spectrometry (GC–MS) analysis was also carried out for the identification of compounds in the hexane soluble fraction (PHFd) with substantial anti-leishmanial activities. The antipromastigote activity and cytotoxicity of this fraction were evaluated by the tetrazolium MTT assay. Other biochemical and physiological parameters were studied by microscopic observation and flow cytometric analyses.

Results

PHFd showed considerable activity against L. donovani promastigotes (IC₅₀: 20 µg/ml). The PHFd also inhibited in vitro growth of L. major LV39 promastigotes dose dependently with an IC₅₀ of 40 µg/ml. The GC–MS studies of this particular fraction revealed the presence of four major compounds with different retention times (RT) of 26.08, 33.11, 36.41, and 41.20 min. In this study, we also established that PHFd could induce DNA damage and subsequent apoptosis of L. donovani promastigotes with a concomitant increase in generations of reactive oxygen species (ROS) in a time-dependent manner. This fraction was also found to be effective in nitric oxide-mediated inhibition of intracellular amastigotes (IC₅₀:12.5 µg/ml) without any noticeable cytotoxicity towards murine splenocytes in vitro.

Conclusion

This study provides the basis for additional phytochemical and pharmacological studies on the antiprotozoal applications of P. hysterophorus.

中文翻译：

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从 Parthenium hysterophorus 叶子中分离的半纯化馏分的潜在抗利什曼原虫活性

目的

从目前的角度来看，杜氏利什曼原虫耐药菌株的出现和使用常规抗利什曼原虫疗法导致的严重副作用，迫切需要开发针对这种寄生虫的新型药物。我们已经探索了次生植物代谢物作为治疗内脏利什曼病 (vl) 的替代选择的有效性。

方法

植物Parthenium hysterophorus L . （菊科）采自印度西孟加拉邦 Barasat 的西孟加拉州立大学校园。这种植物的叶子用不同的溶剂萃取，如乙酸乙酯、水、石油醚和己烷。还进行了气相色谱-质谱 (GC-MS) 分析，以鉴定己烷可溶部分 (PHFd) 中具有显着抗利什曼原虫活性的化合物。该部分的抗前鞭毛体活性和细胞毒性通过四唑 MTT 测定进行评估。通过显微观察和流式细胞术分析研究了其他生化和生理参数。

结果

PHFd 对L. donovani前鞭毛体表现出相当大的活​​性(IC ₅₀ : 20 µg/ml)。PHFd 还剂量依赖性地抑制L. Major LV39 前鞭毛体的体外生长，IC ₅₀为 40 µg/ml。该特定馏分的 GC-MS 研究表明存在四种主要化合物，其保留时间 (RT) 分别为 26.08、33.11、36.41 和 41.20 分钟。在这项研究中，我们还建立了PHFd可诱导DNA损伤和随后的细胞凋亡杜氏利什曼原虫前鞭毛体以时间依赖性方式伴随活性氧 (ROS) 的世代增加。还发现该部分可有效抑制一氧化氮介导的细胞内无鞭毛体 (IC ₅₀ :12.5 µg/ml)，而在体外对小鼠脾细胞没有任何明显的细胞毒性。

结论

本研究为P. hysterophorus抗原生动物应用的额外植物化学和药理学研究奠定了基础。