Valadares Diogo G, Duarte Mariana C, Oliveira Jamil S, Chávez-Fumagalli Miguel A, Martins Vivian T, Costa Lourena E, Leite João Paulo V, Santoro Marcelo M, Régis Wiliam C B, Tavares Carlos A P, Coelho Eduardo A F
Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Parasitol Int. 2011 Dec;60(4):357-63. doi: 10.1016/j.parint.2011.06.001. Epub 2011 Jun 24.
Leishmaniasis is a major public health problem, and the alarming spread of parasite resistance underlines the importance of discovering new therapeutic products. The present study aims to investigate the in vitro leishmanicidal activity of an Agaricus blazei Murill mushroom extract as compared to different Leishmania species and stages. The water extract proved to be effective against promastigote and amastigote-like stages of Leishmania amazonensis, L. chagasi, and L. major, with IC(50) (50% inhibitory concentration) values of 67.5, 65.8, and 56.8 μg/mL for promastigotes, and 115.4, 112.3, and 108.4 μg/mL for amastigotes-like respectively. The infectivity of the three Leishmania species before and after treatment with the water extract was analyzed, and it could be observed that 82%, 57%, and 73% of the macrophages were infected with L. amazonensis, L. major, and L. chagasi, respectively. However, when parasites were pre-incubated with the water extract, and later used to infect macrophages, they were able to infect only 12.7%, 24.5%, and 19.7% of the phagocytic cells for L. amazonensis, L. chagasi, and L. major, respectively. In other experiments, macrophages were infected with L. amazonensis, L. chagasi, or L. major, and later treated with the aforementioned extract, presented reductions of 84.4%, 79.6%, and 85.3% in the parasite burden after treatment. A confocal microscopy revealed the loss of the viability of the parasites within the infected macrophages after treatment with the water extract. The applied extract presented a low cytotoxicity in murine macrophages and a null hemolytic activity in type O(+) human red blood cells. No nitric oxide (NO) production, nor inducible nitric oxide syntase expression, could be observed in macrophages after stimulation with the water extract, suggesting that biological activity may be due to direct mechanisms other than macrophage activation by means of NO production. In conclusion, the results demonstrate that the A. blazei Murill water extract can potentially be used as a therapeutic alternative on its own, or in association with other drugs, to treat Visceral and Cutaneous Leishmaniasis.
利什曼病是一个重大的公共卫生问题，寄生虫耐药性的惊人传播凸显了发现新治疗产品的重要性。本研究旨在调查姬松茸提取物对不同利什曼原虫物种和阶段的体外杀利什曼活性。水提取物被证明对亚马逊利什曼原虫、恰加斯利什曼原虫和硕大利什曼原虫的前鞭毛体和无鞭毛体样阶段有效，前鞭毛体的IC(50)（50%抑制浓度）值分别为67.5、65.8和56.8 μg/mL，无鞭毛体样的IC(50)值分别为115.4、112.3和108.4 μg/mL。分析了三种利什曼原虫在用该水提取物处理前后的感染性，可以观察到分别有82%、57%和73%的巨噬细胞被亚马逊利什曼原虫、硕大利什曼原虫和恰加斯利什曼原虫感染。然而，当寄生虫与水提取物预孵育，然后用于感染巨噬细胞时，它们分别只能感染12.7%、24.5%和19.7%的吞噬细胞，对应于亚马逊利什曼原虫、恰加斯利什曼原虫和硕大利什曼原虫。在其他实验中，巨噬细胞被亚马逊利什曼原虫、恰加斯利什曼原虫或硕大利什曼原虫感染，然后用上述提取物处理，处理后寄生虫负荷分别降低了84.4%、79.6%和85.3%。共聚焦显微镜显示，用水提取物处理后，感染巨噬细胞内的寄生虫活力丧失。所应用的提取物在小鼠巨噬细胞中表现出低细胞毒性，在O(+)型人红细胞中无溶血活性。用水提取物刺激巨噬细胞后，未观察到一氧化氮（NO）产生，也未观察到诱导型一氧化氮合酶表达，这表明生物活性可能归因于除通过产生NO激活巨噬细胞之外的直接机制。总之，结果表明，姬松茸水提取物有可能单独或与其他药物联合用作治疗内脏利什曼病和皮肤利什曼病的替代疗法。
