Santello Fabrícia Helena, Frare Eduardo Osório, dos Santos Carla Domingues, Toldo Míriam Paula Alonso, Kawasse Laura Midori, Zucoloto Sérgio, do Prado José Clóvis
Laboratório de Parasitologia, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto FCFRP-USP, Universidade de São Paulo, Ribeirão Preto, SP, Brasil.
J Pineal Res. 2007 Apr;42(4):359-63. doi: 10.1111/j.1600-079X.2007.00427.x.
Prior studies show that melatonin enhances the immune response. This study investigated the possible therapeutic effects of melatonin during the course of Trypanosoma cruzi infection. T. cruzi-infected male Wistar rats were orally treated with 5 mg/kg body weight/day of melatonin. Animals treated with melatonin showed a significant reduction in the number of blood trypomastigotes during the acute phase of infection compared with untreated animals (P<0.05). A significant increase in leucocytes numbers during the peak of parasitaemia was also observed (P<0.05). Moreover, both prior and concomitant treatment with melatonin increased interleukin-2 levels, especially 9 days postinfection (P<0.05). Histopathological observations of heart tissue revealed that melatonin administration also resulted in fewer and smaller amastigote burdens, and less inflammatory infiltrate and tissue disorganization, indicating a reduced parasitism of this tissue. These results show that melatonin is effective in controlling parasite replication and suggest that melatonin might serve as an effective therapeutic agent in the treatment of American trypanosomiasis.
先前的研究表明褪黑素可增强免疫反应。本研究调查了褪黑素在克氏锥虫感染过程中可能的治疗作用。用体重5毫克/千克/天的褪黑素对感染克氏锥虫的雄性Wistar大鼠进行口服治疗。与未治疗的动物相比，用褪黑素治疗的动物在感染急性期血液中锥鞭毛体数量显著减少（P<0.05）。在寄生虫血症高峰期白细胞数量也显著增加（P<0.05）。此外，感染前和感染期间用褪黑素治疗均增加了白细胞介素-2水平，尤其是在感染后9天（P<0.05）。心脏组织的组织病理学观察表明，给予褪黑素还导致无鞭毛体负荷减少且体积变小，炎症浸润和组织紊乱减轻，表明该组织中的寄生虫感染减少。这些结果表明褪黑素在控制寄生虫复制方面有效，并提示褪黑素可能作为治疗美洲锥虫病的有效治疗剂。
