Atividade antifúngica e citotóxica de substâncias de origem sintética

Abstract

Over the last ten years, the incidence of fungal infections has increased. Fungi can cause serious diseases in humans, several of them fatal if untreated and among these include those caused by agents, yeasts and dimorphic. People with immune deficiencies are particularly susceptible to opportunistic fungal diseases, especially of the genera as Aspergillus spp., Candida spp., Cryptococcus spp., Rhodotorula spp., Aspergillus spp. and Pneumocystis spp. With the emergence of antimicrobial drugs used in the treatment of infectious diseases, increased life expectancy of patients with various infections and battled various ailments, and this discovery of enormous importance not only in health but also in the economy. However, the overuse or misuse of these favor the development of resistant strains, this becoming a major public health problem worldwide and leading to the need of finding new alternatives of a drug antifungal. This study aimed to evaluate the antifungal activity against Cryptococcus laurenthi, Geotrichum spp., Candida albicans, C. parapsilosis, C. guilhermodii, Trichosporum asahii and Rhodotorula spp. nineteen molecules of synthetic origin class of thiazolidinones and its cytotoxicity. The study of antifungal activity was performed by the broth microdilution technique (MC), with the determination of Minimum Inhibitory Concentration (MIC) and minimum fungicidal concentration (MFC) following the protocols of the CLSI M27-A3. The cytotoxicity study with mice fibroblast cells 3T3/NIH was performed using the tetrazolium salt assay (MTT). Among the yeasts tested, T. asahii and Rhodotorula spp. showed greater susceptibility molecule of synthetic origin, V58, MIC 10.41 mg / mL and 35µg/mL, respectively. None of the nineteen molecules were toxic at the highest concentration tested (787µg/mL), with the exception of B25 molecule that decreased by more than 16% cell viability. It was concluded that Candida spp. the genre is less susceptible to this class of thiazolidinones than other fungal isolates, T. asahii and Rhodotorula spp. The results presented herein allow to foresee that knowledge of the compatibility of non-cytotoxic synthetic molecules on the development of fungi is essential for the future development of an antifungal drug.