Antifungal mechanism of action of Schinus lentiscifolius Marchand essential oil and its synergistic effect in vitro with terbinafine and ciclopirox against dermatophytes.

OBJECTIVES: The aim of this study was to evaluate the antifungal, antichemotactic and antioxidant activities of Schinus lentiscifolius essential oil, as well as its combined effect with terbinafine and ciclopirox, against dermatophytes. METHODS: Essential oil was analysed by GC-MS. The antifungal activity and the mechanism of action were determined by broth microdilution, sorbitol and ergosterol assays, as well as scanning electron microscopy. The checkerboard method was used for evaluating the interactions with commercial antifungal agents. The antioxidant and antichemotactic activities were measured using the DPPH and the modified Boyden chamber methods, respectively. KEY FINDINGS: Chemical analysis revealed the presence of 33 compounds, the primary ones being γ-eudesmol (12.8%) and elemol (10.5%). The oil exhibited 97.4% of antichemotactic activity and 37.9% of antioxidant activity. Antifungal screening showed effect against dermatophytes with minimum inhibitory concentration values of 125 and 250 µg/ml. Regarding the mechanisms of action, the assays showed that the oil can act on the fungal cell wall and membrane. Synergistic interactions were observed using the combination with antifungals, primarily terbinafine. CONCLUSIONS: Schinus lentiscifolius essential oil acted as a chemosensitizer of the fungal cell to the drug, resulting in an improvement in the antifungal effect. Therefore, this combination can be considered as an alternative for the topical treatment of dermatophytosis.

Determinación de ocratoxina-a por HPLC con detección por fluorescencia (HPLC-FL): un nuevo método estandarizado para muestras de trigo / Ochratoxin-a determination by HPLC with fluorescence detection(HPLC-FL): a new standardization method for wheat samples

El objetivo principal de este estudio fue evaluar la presencia de Ocratoxina-A (OTA) en los granos del trigo y harina del trigo realizadas por un nuevo método de determinación que usa la cromatografía líquida de alta resolución (CLAR) acoplada al descubridor delfluorimetrio. El experimento usó seis muestras de grano de trigo del lugar del almacenamiento diferente a la industria local de Chapeco (SC), Brasil Sur, en agosto, 2008. El extracto de OTA era llevado a cabo usando el acetonitrila: agua (120:80 vlv) como solventes. Después el suprenadante fue filtrado, y aplicado en la columna del inmunoafinidad específica a OTA. Además, la columna se lavó con agua y la toxina era el eluido con el metanol. La determinación del OTA se realizó por detección de fluorescencia acoplado al aparato de HPLC. Los volúmenes de OTA en los granos del trigo y harina del trigo eran entonces los determínate y los resultados mostraron una concentración de OTA menor que los límites exigidos por la legislación internacional.

The main objective of this study was to evaluate the presence of Ochratoxin A (OTA) in wheat grains and wheat flour samples using a new high performance liquid chromatography (HPLC) method. The experiment used six wheat grain samples from different industry storage place from Chapeco (SC), South Brazil, on August 2008. The OTA extraction was carried out using acetonitrile: water (120:80 v/v) as solvent. Thereafter, the supernatant was filtered, and applied on OTA-specific immunoafinity column to HPLC Furthermore, the column was washed with water and the toxin was eluted with methanol. The OTA wheat grains and wheat flour concentration were analyzed by a fluorescence detector coupled to the HPLC apparatus. The results showed a smaller OTA concentration than the limits set by international legislation.