do Rosário Carla Janaina Rebouças Marques, da Rocha Cláudia Quintino, de Aguiar Daniel Moura, Lima Cristian Alex Aquino, Silveira Daniella Patrícia Brandão, Leite José Antônio Costa, Coutinho Denise Fernandes, Melo Ferdinan Almeida
Laboratory of Immunodiagnosis, State University of Maranhão, São Luís, MA, Brazil.
Laboratory of Advanced Studies in Phytomedicines, Department of Chemistry, Center for Exact Sciences and Technology, Federal University of Maranhão, São Luís, MA, Brazil.
AMB Express. 2019 Apr 29;9(1):58. doi: 10.1186/s13568-019-0780-y.
Canine Monocytic Ehrlichiosis (CME) is an infectious disease caused by the rickettsia organism Ehrlichia canis which is transmitted mainly the ixodid brown dog tick Rhipicephalus sanguineus. The prevalence of E. canis infection has been increasing in recent years. The World Health Organization has been warned about antibiotics resistance and one of the way to prevent this situation is found new compound with this property. Doxycycline is the treatment of choice for this tick-borne disease. Adverse effects are noted in dogs that are sensitive to this drug. Antibiotic resistance may also occur. The present study aimed to evaluate the anti-Ehrlichia properties of the essential oil of the aerial parts of Ageratum conyzoides L. in infected DH82 cells, as well as its anti-Ehrlichia activity associated with doxycycline using the checkerboard assay. A. conyzoides is a native plant from northeast Brazil with many reports of ethnopharmacological applications. The essential oil of A. conyzoides was extracted from the aerial parts of the plant using the hydrodistillation method. E. canis-infected DH82 cells were cultured in DMEM (Dulbecco's Modified Eagle Medium), maintained at 37 °C and 5% CO, and standardized at a 70% infection rate for the initiation of treatment protocols. The tests were first carried out with the aim of defining the IC. The combined effect of doxycycline and A. conyzoides essential oil was then determined using the checkerboard dilution technique (checkerboard method) in which the IC was 200 µg/mL. The doxycycline reduction index from the combined effect was 4.90 times resulting in a synergistic effect. To the authors' knowledge, this is the first alternative treatment (alternative therapy) based on bioactive molecules that have antibacterial activity against E. canis.
犬单核细胞埃立克体病（CME）是一种由立克次氏体病原体犬埃立克体引起的传染病，主要通过硬蜱科的棕色犬蜱血红扇头蜱传播。近年来，犬埃立克体感染的患病率一直在上升。世界卫生组织已就抗生素耐药性发出警告，预防这种情况的一种方法是找到具有这种特性的新化合物。强力霉素是这种蜱传疾病的首选治疗药物。对该药物敏感的犬会出现不良反应。也可能会出现抗生素耐药性。本研究旨在评估藿香蓟地上部分精油在感染DH82细胞中的抗埃立克体特性，以及使用棋盘法评估其与强力霉素相关的抗埃立克体活性。藿香蓟是一种原产于巴西东北部的植物，有许多关于其民族药理学应用的报道。藿香蓟精油采用水蒸馏法从植物地上部分提取。将感染犬埃立克体的DH82细胞在DMEM（杜氏改良 Eagle 培养基）中培养，保持在37°C和5%二氧化碳环境下，并在70%感染率下标准化，以启动治疗方案。首先进行试验以确定IC。然后使用棋盘稀释技术（棋盘法）确定强力霉素和藿香蓟精油的联合作用，其中IC为200μg/mL。联合作用导致的强力霉素降低指数为4.90倍，产生协同效应。据作者所知，这是第一种基于对犬埃立克体具有抗菌活性的生物活性分子的替代治疗方法（替代疗法）。
