In vitro antifungal susceptibility, in vivo antifungal activity and security from a natural product obtained from sunrise oil (AMO 3 ) against dermatophytesThis work studied safety and antifungal activity of ozonized sunfl ower oil (AMO 3 ) against dermatophytes. AMO 3 was prepared through a new original process that modifi es the oil before ozonation by alcoholic catalytic esterifi cation. Susceptibility was studied in 41 dermatophytes by agar diffusion and broth microdilution tests. The experimental model to assess the topical safety of the oil included 60 CF1 mice divided in three groups that were treated with vaseline (control), 1% AMO 3 and 50% AMO3 (overdose), respectively. Then, experimental dermatophytosis was induced in CF1 mice. Seventy-fi ve individuals were selected and divided in 5 groups that were treated once a day with placebo, cream with 1%, 2% and 3% AMO 3 plus an untreated control group. This new natural product showed antifungal activity against all strains studied. The MIC ranged between was 0,125 and 1%, while minimum fungicidal concentration (MFC) was 2%. The application of vaseline and AMO 3 1% and 50% did not produce clinical or histopathological lesions. The mice with dermatophytosis that were treated with 1%, 2% and 3% AMO 3 showed 100% clinical cure and 94% average mycological cure, exceeding placebo and control groups (p < 0,05). This product exhibits high antifungal activity and could be a safe alternative for ringworm topical treatment.Key words: Natural antifungal, ozonized oil, dermatophytosis. Palabras clave: Antifúngico natural, aceite ozonizado, dermatofi tosis.Universidad Mayor.
Facultad de Medicina (PTM, VSV).Laboratorio CENTROVET (PTM).Universidad de Chile.
Facultad de Ciencias Veterinarias yPecuarias (SAC).
Facultad de Medicina (HRB).Los autores declaran no tener conflictos de interés.
IntroducciónL as dermatofi tosis continúan siendo una causa importante de consulta, tanto en humanos como en animales 1 . Son afecciones cutáneas causadas por hongos del grupo dermatofi tos, con afi nidad para crecer sobre la queratina, la que digieren enzimáticamente y consumen como principal fuente de energía. Los dermatofi tos están integrados por los géneros Microsporum, Trichophyton y Epidermophyton, capaces de invadir y mantenerse en tejidos queratinizados, como el estrato córneo de la piel, pelos y uñas, pudiendo transmitirse entre personas, de animales al hombre y viceversa 2 . Clí-nicamente se caracterizan por producir lesiones circulares con un grado variable de eritema, descamación, prurito y alopecia cuando afecta una zona pilosa 2-4 . Según su hábitat y preferencias de hospederos, los dermatofi tos se clasifi can en tres grupos: geofílicos o habitantes del suelo, que ocasionalmente son patógenos para el hombre y los animales; zoofílicos, cuyo hospedero natural son los animales, pero frecuentemente afectan al hombre; y antropofílicos, patógenos exclusivamente humanos [1][2][3][4] . El diagnóstico de las dermatofi tosis se inicia en la anamnesis, con una completa y detallada hist...