Efeitos da imunoestimulação pela Echinacea purpurea (L.) moench sobre a histoarquitetura da parede do cólon de ratos infectados por Toxoplasma gondii

Abstract

Toxoplasma gondii is a mandatory intracellular protozoan causing toxoplasmosis. Infection occurs after ingestion of oocysts, tissue cysts, bradizoites or taquizoites. Exposed to T. gondii, the cells recognize it and secrete pro-inflammatory cytokines, inducing an inflammatory response to host resistance, but which can also cause damage to it. Studies show that the treatment used no longer causes the expected effect. The study aimed to evaluate the alterations in cells and tissues that make up the colon wall of rats inoculated with 500 sporulated oocysts of T. gondii (RH strain, genotype I) and immunostimulated with 100 mg/kg of Echinacea purpurea (L.) Moench. Twenty-four male Rattus norvegicus were randomly separated into four groups (n=6): control group (CG); infected and non-immunostimulated group (GI); immunostimulated control group (GC+EP); and infected and immunostimulated group (GI+EP). The experimental protocol (no. 7633021018) was approved by the ethics committee and at 93 days of age, the rats were euthanized. The colon was collected, fixed and analyzed. Infection as well as immunostimulation caused histomorphometric changes, increased distribution of total mast cells, mast cells and enterochromaphous cells that express 5-HT and in the proportion of intraepithelial lymphocytes in the colon of rats. There was an increase in goblet cells evaluated in the epithelium of the colon. In addition, the infection caused histopathological changes to the colon wall which were attenuated by immunostimulation. In view of the above, our results suggest that part of the changes in cells and tissues that make up the colon wall were attenuated by immunostimulation with E. purpurea.