Composição química e potencialidade anti-Malassezia dos extratos de Rosmarinus officinalis e Origanum vulgare.

Abstract

Malassezia pachydermatis is a yeast considered an opportunistic pathogen of extreme relevance in cases of canine otitis and in veterinary dermatology, becoming a very important therapeutic target to be explored. The plants of the Lamiaceae family as Rosmarinus officinalis and Origanum vulgare, known popularly as “rosemary” and “oregano”, are aromatic and condimentar plants that has shown medicinal properties because they possess active substances with therapeutic potential in several biological activities, among them, antifungal, antibacterial and antiviral. Therefore, this study aimed to characterize the phenolic compounds of aqueous and ethanolic extracts of these plants and to evaluate the antifungal activity against the yeast Malassezia pachydermatis, clinical isolates of otitis and dermatomycosis, by the method of broth microdilution and disk diffusion. The design of the chemical composition of the extracts was performed by high performance liquid chromatography (HPLC) and the evaluation of antifungal activity was performed according to the documents CLSI M27-A3 for microdilution and CLSI M44- A2 for diffusion, adapted for plant extracts. According to the chromatographic analysis, rosmarinic acid and carnosic, and the flavonoids: luteolin, apigenin, kaempferol and quercetin were identified in all extracts analyzed. In relation to the determination of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) all extracts evaluated showed inhibitory and fungicidal activity. The ethanolic extract of oregano was the one that showed the best result having MIC=7.07mg/mL and MFC=24.34 mg/mL. In the evaluation of the sensitivity of the yeast facing rosemary and oregano extracts by disk diffusion method, the aqueous extracts showed no inhibition capacity. Regarding ethanolic extracts of rosemary and oregano there was a halo of inhibition of 6.962mm and 4.771mm, respectively, thus demonstrating a significant difference between the extracts against the yeast tested, however the isolates from skin and ear were not statistically different from the extracts tested. In vitro results allow us to conclude that the extracts showed antifungal action, however in vivo analyses should be performed to confirm these results, in search of therapeutic alternatives for malasseziose.