Biosciences and Biotechnology Postgraduate Program, Carlos Chagas Institute (ICC/Fiocruz-PR), Curitiba, Paraná, Brazil; State University of Londrina (UEL/PR), Laboratory of Immunoparasitology, Londrina, Paraná, Brazil.
State University of Londrina (UEL/PR), Laboratory of Biotransformation and Phytochemistry, Londrina, Paraná, Brazil.
Phytomedicine. 2021 May;85:153536. doi: 10.1016/j.phymed.2021.153536. Epub 2021 Mar 3.
Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the Leishmania genus. Currently, the treatment has limited effectiveness and high toxicity, is expensive, requires long-term treatment, induces significant side effects, and promotes drug resistance. Thus, new therapeutic strategies must be developed to find alternative compounds with high efficiency and low cost. Solidagenone (SOL), one of the main constituents of Solidago chilensis, has shown gastroprotective, anti-inflammatory and immunomodulatory effects.
This study assessed the in vitro effect of SOL on promastigotes and Leishmania amazonensis-infected macrophages, as well its microbicide and immunomodulatory mechanisms.
SOL was isolated from the roots of S. chilensis, 98% purity, and identified by chromatographic methods, and the effect of SOL on leishmanicidal activity against promastigotes in vitro, SOL-induced cytotoxicity in THP-1, J774 cells, sheep erythrocytes, and L. amazonensis-infected J774 macrophages, and the mechanisms of death involved in this action were evaluated.
In silico predictions showed good drug-likeness potential for SOL with high oral bioavailability and intestinal absorption. SOL treatment (10-160 μM) inhibited promastigote proliferation 24, 48, and 72 h after treatment. After 24 h of treatment, SOL at the IC (34.5 μM) and 2 × the IC (69 μM) induced several morphological and ultrastructural changes in promastigotes, altered the cell cycle and cellular volume, increased phosphatidylserine exposure on the cell surface, induced the loss of plasma membrane integrity, increased the reactive oxygen species (ROS) level, induced loss of mitochondrial integrity (characterized by an apoptosis-like process), and increased the number of lipid droplets and autophagic vacuoles. Additionally, SOL induced low cytotoxicity in J774 murine macrophages (CC of 1587 μM), THP-1 human monocytes (CC of 1321 μM), and sheep erythrocytes. SOL treatment reduced the percentage of L. amazonensis-infected macrophages and the number of amastigotes per macrophage (IC 9.5 μM), reduced TNF-α production and increased IL-12p70, ROS and nitric oxide (NO) levels.
SOL showed in vitro leishmanicidal effects against the promastigotes by apoptosis-like mechanism and amastigotes by reducing TNF-α and increasing IL-12p70, ROS, and NO levels, suggesting their potential as a candidate for use in further studies on the design of antileishmanial drugs.
利什曼病是一种由利什曼原虫属原生动物寄生虫引起的被忽视的热带病。目前，这种治疗方法的效果有限且毒性高，费用昂贵，需要长期治疗，会引起明显的副作用，并促进耐药性的产生。因此，必须开发新的治疗策略，以寻找具有高效和低成本的替代化合物。Solidagenone（SOL）是 Solidago chilensis 的主要成分之一，已显示出胃保护、抗炎和免疫调节作用。
本研究评估了 SOL 对前鞭毛体和感染的 Leishmania amazonensis 巨噬细胞的体外作用，以及其杀微生物和免疫调节机制。
从 S. chilensis 的根部分离出 SOL，纯度为 98%，并通过色谱方法进行鉴定，评估 SOL 对体外前鞭毛体的杀利什曼原虫活性、SOL 对 THP-1、J774 细胞、绵羊红细胞和感染的 L. amazonensis J774 巨噬细胞的细胞毒性作用，以及涉及这种作用的死亡机制。
SOL 的体内生物利用度和肠道吸收预测显示出良好的药物样特性，具有较高的口服生物利用度。SOL 处理（10-160 μM）在处理后 24、48 和 72 小时抑制前鞭毛体增殖。在 24 小时的治疗后，SOL 在 IC（34.5 μM）和 2×IC（69 μM）下诱导前鞭毛体发生多种形态和超微结构变化，改变细胞周期和细胞体积，增加细胞膜表面磷脂酰丝氨酸的暴露，诱导质膜完整性丧失，增加活性氧（ROS）水平，诱导线粒体完整性丧失（表现为凋亡样过程），并增加脂滴和自噬空泡的数量。此外，SOL 对 J774 鼠巨噬细胞（CC 为 1587 μM）、THP-1 人单核细胞（CC 为 1321 μM）和绵羊红细胞的细胞毒性较低。SOL 处理降低了感染的 L. amazonensis 巨噬细胞的百分比和每个巨噬细胞中的无鞭毛体数量（IC 9.5 μM），降低了 TNF-α的产生并增加了 IL-12p70、ROS 和一氧化氮（NO）水平。
SOL 通过类似凋亡的机制对前鞭毛体和通过减少 TNF-α和增加 IL-12p70、ROS 和 NO 水平对无鞭毛体表现出体外杀利什曼原虫作用，表明其作为抗利什曼药物设计进一步研究的候选药物的潜力。
