Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee DD1 5EH, UK.
Instituto de Física, Universidade de São Paulo, Rua do Matão, 1, 05508-090, São Paulo, SP, Brazil.
Chem Biol Interact. 2020 Dec 1;332:109296. doi: 10.1016/j.cbi.2020.109296. Epub 2020 Oct 20.
Leishmaniasis is a parasitic neglected tropical disease and result in a broad spectrum of clinical manifestations, ranging from a single ulceration to a progressive and fatal visceral disease. Comprising a limited and highly toxic therapeutic arsenal, new treatments are urgently needed. Targeting delivery of drugs has been a promising approach for visceral leishmaniasis (VL). Phosphatidylserine-liposomes have demonstrated superior efficacy in VL, targeting intracellular parasites in host cells through macrophage scavenger receptors. In this work, we investigated the in vitro and in vivo efficacy of the antihelminthic drug nitazoxanide in a nanoliposomal formulation against Leishmania (L.) infantum. Physicochemical parameters of liposomes containing nitazoxanide (NTZ-LP) were determined by dynamic light scattering and small angle X-ray scattering. The efficacy of the formulation was verified in an intracellular amastigote model and in an experimental hamster model. Our findings showed that NTZ-LP was able to eliminate the amastigotes inside the host cell with an IC value of 16 μM. NTZ-LP was labelled a fluorescent probe and by spectrofluorimetry, we observed that the infected macrophages internalized similar levels of the drug to the uninfected cells. The confocal microscopy images confirmed the uptake and demonstrated a diffuse distribution of the NTZ-LP in the cytoplasm of Leishmania-infected macrophages, with the vesicles in a closer proximity to the parasites. For the in vivo efficacy, the liposomal NTZ-LP was administrated intraperitoneally to Leishmania-infected hamsters for 10 consecutive days at 2 mg/kg/day. By qPCR we demonstrated a reduction of the parasite burden by 82% and 50% in the liver (p < 0.05) and spleen (p < 0.05), respectively. NTZ (non-liposomal) was administered at 100 mg/kg/day per oral (p.o.) for the same period, but demonstrated no efficacy. This liposomal formulation ensured a targeting delivery of NTZ to the intracellular parasites, resulting in an good efficacy at a low dose in animals, and it may represent a new candidate therapy for VL.
利什曼病是一种寄生性的被忽视的热带病，可导致广泛的临床表现，从单一溃疡到进行性和致命的内脏疾病不等。由于治疗方法有限且毒性高，因此迫切需要新的治疗方法。靶向药物递送一直是内脏利什曼病（VL）的一种有前途的方法。磷脂酰丝氨酸脂质体已证明在 VL 中具有更高的疗效，通过巨噬细胞清道夫受体靶向宿主细胞内的细胞内寄生虫。在这项工作中，我们研究了纳米脂质体制剂中驱虫药硝唑尼特（NTZ）对利什曼原虫（L.）婴儿的体外和体内疗效。通过动态光散射和小角 X 射线散射确定了含硝唑尼特（NTZ-LP）的脂质体的理化参数。在细胞内无鞭毛体模型和实验性仓鼠模型中验证了该制剂的疗效。我们的研究结果表明，NTZ-LP 能够以 16μM 的 IC 值消除宿主细胞内的无鞭毛体。NTZ-LP 被标记为荧光探针，通过荧光光谱法，我们观察到感染的巨噬细胞摄取与未感染细胞相似水平的药物。共聚焦显微镜图像证实了摄取，并证明了 NTZ-LP 在感染利什曼原虫的巨噬细胞细胞质中的扩散分布，囊泡与寄生虫更接近。对于体内疗效，将脂质体 NTZ-LP 以 2mg/kg/天的剂量连续 10 天腹膜内给药给感染利什曼原虫的仓鼠。通过 qPCR，我们证明在肝脏（p<0.05）和脾脏（p<0.05）中寄生虫负担分别减少了 82%和 50%。在同一时期，以 100mg/kg/天的剂量经口（p.o.）给予 NTZ（非脂质体），但没有疗效。这种脂质体制剂确保了 NTZ 对细胞内寄生虫的靶向递送，从而在动物中以低剂量实现了良好的疗效，它可能成为 VL 的新候选治疗方法。
