Avaliação do potencial terapêutico da aplicação tópica do óleo de copaíba e do trans-cariofileno na dermatite atópica experimental

Abstract

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by intense pruritus, eczematous lesions, xerosis and lichenification. In addition to histological changes, AD is marked by immunological changes, such as an increased number of mast cells, increased IgE and changes in CD4+ T lymphocyte subpopulations. Because the use of corticosteroids and immunomodulators causes several side effects, there is a need for new phytotherapeutic agents with anti- inflammatory activities that lack adverse effects. Objective: The objective of this study was to evaluate the therapeutic potential of copaiba oil and trans-caryophyllene in skin lesions from experimental AD. Methods: Balb/c mice (N = 32) were divided into groups: G0 (no AD), GI (inflamed group, LesAD), GII (dexamethasone), GIII (tacrolimus), GIV (copaiba oil), and GV (trans-caryophyllene). Dermatitis was induced with dinitrochlorobenzene and ovalbumin for seven days, and treatments started on the eighth day for seven days. Euthanasia was performed on the 15th day to obtain the lesioned area for histopathological analysis (hematoxylin-eosin (HE) and toluidine blue) and immunohistochemistry (T-bet, GATA-3, IL-17, Foxp3 and eosinophilic peroxidase). Results: HE-stained samples showed all the characteristics necessary for the diagnosis of AD in GI; GII was similar to GI but with a different infiltrate; GIII exhibited an intraepithelial lymphocytic infiltrate; and in GIV and GV, there was good epidermal recovery. In samples stained with toluidine blue, high numbers of mast cells were observed in GI, GII, GIII and GV compared to G0, whereas GIV exhibited a considerable decrease in mast cells. Copaiba oil significantly reduced T-bet, GATA-3, Foxp3 and eosinophilic peroxidase expression observed by immunohistochemistry. Conversely, trans-caryophyllene reduced GATA-3, Foxp3 and eosinophilic peroxidase expression. Conclusions & Clinical Relevance: The results suggest that copaiba oil and trans-caryophyllene are potential substrates for new drugs to be used in AD treatment.