Bioprospecção da atividade antigúngica e da citoxicidade do óleo essencial de Patchouli (pogostemon cablin benth)

Abstract

The incidence of infections caused by Candida has increased worldwide and these strains are becoming resistant to their respective drugs. The search for new drugs with greater efficacy and safety is necessary and in this logic, essential oils (EOs) stand out, which are a complex mixture of volatile compounds and present several relevant biological activities, but there are few studies on the potential beneficial and/or adverse effects. In this sense, the objective of this study was to evaluate the antifungal and cytotoxic activities of Patchouli (Pogostemon cablin Benth) essential oil. In the evaluation of the antifungal activity it was used different strains of Candida genus and it was determined the Minimum Inhibitory Concentration (MIC) and the minimum fungicidal concentration (MFC), by microdilution technique. The interference of the EO on the cell wall and its potential for rupture was done by MIC in the presence of sorbitol, and the interference on the cell membrane was done by MIC with ergosterol. Also, the interference of EO on the resistance to standard antifungal drugs was evaluated, in the absence and in the presence of EO at subinhibitory concentrations. For cytotoxic activity studies, human RBCs of blood types A, B and O were used and the hemolytic and antihemolytic activity was evaluated. The analyses revealed that the EO showed excellent antifungal activity against clinical strains of C. parapsilosis and C. albicans with a MIC and MIC between 4 and 16 μg/mL, this effect being fungicidal in nature. Its mechanism of action involves no effect on the cell wall as well as on the plasma membrane. It promoted a synergistic effect when associated with amphotericin B. The effect on red blood cells showed a low percentage of hemolysis for red blood cells of the ABO system at a concentration of 50 to 100 μg/mL. In addition, it shows moderate anti-hemolytic effect at concentrations of 500 to 1000 μg/mL for blood types B and O. Considering the results obtained in the in vitro cytotoxicity study and the pharmacological activity, it can be seen that Patchouli OE becomes a promising candidate for use of its bioactive properties in herbal medicines, but auxiliary studies are needed as in vivo toxicity and pharmacological to better elucidate the mechanisms of action of this compound.