Caracterização toxicológica e funcional do extrato aquoso de Waltheria douradinha

Abstract

The inflammation of the external auditory canal is highlighted in the medical clinic of small animals by the high number of dogs that present the disease throughout their life. The causative factors of otitis can be described as primary, predisposing or perpetuating, and recklessness in its diagnosis added to the mismanagement of allopathic drugs causes the index of animals with chronic disease to be elevated. Thus, alternatives to conventional treatment are necessary. Phytotherapy has been growing and being stimulated, however, several plants with medicinal potential do not yet have their action scientifically proven, having only empirical recommendations. Waltheria douradinha, is a plant of the family Malvaceae whose actions have not yet been completely unraveled. Empirical options make it a choice for the treatment of inflammatory diseases. In this aspect, we associate the need for scientific verification of the action of W. douradinha in the treatment of external otitis in small animals. In this way, this study aimed to review points considered relevant for the best conduct in cases of external otitis, in order to better understand the size of this medical picture; To evaluate the toxicity of the aqueous extract of W. douradinha through the use in ex vivo test in ocular globe of chickens, by macroscopic parameters and histopathological analysis; to test the in vitro cytotoxic effect caused by the exposure of cells to the aqueous extract of W. douradinha; and finally to evaluate the effect of experimentally induced infectious external otitis treatment on wistar rats through the use of aqueous extract of W. douradinha. The evaluation of the toxicity of the aqueous extract of W. douradinha in ex vivo model took into account parameters such as retention of fluorescein, opacity and corneal swelling, in addition to the histopathological analysis. The cytotoxic assay was performed by exposing subcultured cells to 96-well plates in the aqueous extract of W. douradinha, after 48 hours the neutral red dye was added and a plate spectrophotometer was read. To observe the treatment of external otitis, wistar rats were induced to inflammation through the instillation of chroton oil in their auditory conducts. The randomly divided animals were treated with the aqueous extract of W. douradinha for two, four and six days at concentrations of 100, 50 and 25%, in addition to a control group containing physiological solution. The parametersof weight, edema of the auricular pinna were evaluated together with the observationthrough vídeo otoscopy of the diameter of the light of the external auditory canal, with its coloration and effusion, together with the histopathological analysis. With the results, it was concluded that the aqueous extract of W. douradinha has a low degree of toxicity due to the macroscopic andhistopathological analyzes carried out in an ex vivo model, using a chicken eyeball; the aqueousextract of Waltheria douradinha was shown to possess cytotoxicactivity at concentrations of 1, 5 and 10%,; Finally, evidence has been provided that the aqueous extract of W. douradinha can be topically active for the treatment of external otitis induced by chroton oil in rat model.