Evaluation of in vitro antifungal properties of Thanatin peptide and Chinaberry extract on fungal pathogens of bovine mastitis

Mastitis is one of the most important diseases in dairy cattle. Administration of synthetic antibiotics for treatment of mastitis leads to drug-resistance bacteria or fungi. Hence, the use of natural alternatives such as antimicrobial peptides and plant extracts has been considered as alternatives to common antibiotics. The aim of this study was to evaluate the effect of Thanatin peptide and Chinaberry extract against fungal factors of bovine mastitis such as Candida parapsilosis, Candida albicans and Mucor spp in vitro. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) were determined based on broth micro-dilution method by 96-well plate with four replications using Chinaberry (Melia azedarach) extract and thanatin peptide on three mastitis-causing fungi. The results showed that the thanatin was effective on growth inhibition of all three fungi. Thanatin was more effective against Candida albicans and parapsilosis. Chinaberry extract with MIC of 6250 µg / ml and MFC of 12500 µg / ml had the greatest effect on Candida parapsilosis. Applied Chinaberry extract had no effect on Mucor spp fungi while thanatin showed an antifungal activity against this species. This study proved that Chinaberry extract and Thanatin peptide could show suitable antifungal activity against factors for mastitis includes Candida parasilosis, Candida albicans and Mucor spp in vitro although the antifungal activity of this peptide should be investigated in clinical trials in the future.