Mwololo Samuel W, Mutiso Joshua M, Macharia John C, Bourdichon Alain J, Gicheru Michael M
Department of Zoological Sciences, Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya. ; Department of Tropical and Infectious Diseases, Institute of Primate Research, P. O. Box 24481-00502, Karen, Nairobi, Kenya.
Department of Zoological Sciences, Kenyatta University, P. O. Box 43844-00100, Nairobi, Kenya.
J Biomed Res. 2015 May;29(3):214-23. doi: 10.7555/JBR.29.20140072. Epub 2015 Mar 4.
The present study evaluated the in vitro activity and in vivo efficacy of diminazene combined with chloroquine as a potential drug against Leishmania donovani. Amphotericin B was used as a positive control drug. In vitro activity involved incubation of various drug concentrations with promastigotes or vero cells in culture before determination of parasite growth inhibition or cell death while in vivo evaluations involved infection of various mice groups with virulent L. donovani parasites and treatment with test drug compounds following disease establishment. Weight changes in experimental mice were also evaluated before infection and throughout the experiment. The results indicated that the diminazene-chloroquine combination was at least nine times more efficacious than individual drugs in killing promastigotes in culture. The diminazene-chloroquine combination was safer (Ld50 = 0.03±0.04) than Amphotericin B (Ld50 = 0.02±0.01). Body weight in infected mice increased significantly (P = 0.0007) from day 7 to day 37 following infection (P = 0.026). However, body weight remained comparable in all mice groups during treatment (P = 0.16). The diminazene-chloroquine combination significantly reduced splenic parasite numbers as compared to individual drug therapies (P = 0.0001) although Amphotericin B was still more efficacious than any other treatment (P = 0.0001). Amongst the test compounds, the diminazene-chloroquine combination showed the lowest level of IgG antibody responses with results indicating significant negative correlation between antileishmanial antibody responses and protection against disease. These findings demonstrate the positive advantage and the potential use of a combined therapy of diminazene-chloroquine over the constituent drugs. Further evaluation is recommended to determine the most efficacious combination ratio of the two compounds.
本研究评估了地美硝唑与氯喹联合使用作为抗杜氏利什曼原虫潜在药物的体外活性和体内疗效。两性霉素B用作阳性对照药物。体外活性包括在测定寄生虫生长抑制或细胞死亡之前，将各种药物浓度与培养中的前鞭毛体或 vero 细胞一起孵育，而体内评估则涉及用强毒杜氏利什曼原虫感染不同小鼠组，并在疾病确立后用受试药物化合物进行治疗。还在感染前和整个实验过程中评估了实验小鼠的体重变化。结果表明，地美硝唑 - 氯喹组合在杀死培养中的前鞭毛体方面比单一药物至少有效九倍。地美硝唑 - 氯喹组合比两性霉素B更安全（半数致死剂量Ld50 = 0.03±0.04）（两性霉素B的Ld50 = 0.02±0.01）。感染小鼠的体重在感染后第7天至第37天显著增加（P = 0.0007）（P = 0.026）。然而，在治疗期间所有小鼠组的体重保持相当（P = 0.16）。与单一药物疗法相比，地美硝唑 - 氯喹组合显著降低了脾脏寄生虫数量（P = 0.0001），尽管两性霉素B仍然比任何其他治疗更有效（P = 0.0001）。在受试化合物中，地美硝唑 - 氯喹组合显示出最低水平的IgG抗体反应，结果表明抗利什曼原虫抗体反应与疾病保护之间存在显著负相关。这些发现证明了地美硝唑 - 氯喹联合疗法相对于单一药物的积极优势和潜在用途。建议进一步评估以确定这两种化合物最有效的组合比例。
