Desenvolvimento, caracterização e avaliação antifúngica de nanoemulsões contendo óleo essencial de lippia origanoides kunth frente a candida albicans na forma planctonica e de biofilme

Abstract

Fungal infections caused by Candida albicans are a global health problem. Antifungals are used to treat infections caused by these fungi, but these fungi are increasingly developing resistance to these medications. Nanoemulsions based on plant essential oils are a promising new approach for treating fungal infections. The present study aimed to prepare and characterize nanoemulsions of Lippia origanoides essential oil, and analyze their antifungal activity against C. albicans in planktonic and biofilm form, in addition to verifying their cytotoxicity. Sodium alginate nanoemulsions were prepared in different concentrations of essential oil, sunflower oil and surfactant to investigate ideal formulations regarding their stability and antifungal efficiency. The results showed that the nanoemulsions were stable for more than 60 days, with acidic pH, particle size ranging from 180 to 500 nanometers, negative zeta potential and low polydispersity index. Photomicrographs revealed that the addition of sunflower oil helped form nanoemulsions. Infrared Spectroscopy (FT-IR) analyzes showed the presence of the polysaccharide alginate. The antifungal results of the essential oil and nanoemulsions showed the MIC ranged from 0.078 to 0.312 mg/mL and the CFM ranged from 0.625 mg/mL. The nanoemulsion was more effective than the free essential oil in eradicating the biofilm, eliminating up to 89.7% of its mass. However, nanoemulsions were also found to be more cytotoxic. In conclusion, alginate nanoemulsions containing L. origanoides essential oil are a promising approach for the treatment of C. albicans fungal infections.