Antifungal activities of Camellia sinensis crude extract, mixture with milk, on selected pathogenic and mycotoxic fungi

Camellia sinensis extracts have been documented to have antibacterial activity but little knowledge on their antifungal activity. The aqueous extracts of C. sinensis (tea) both green and black, mixed with milk in equal ratio parts, referred as mixture  were investigated for their antifungal activity and minimum inhibitory concentrations (MICs) against seven fungal species; Green and black tea crude extracts (100 mgmL-1) were evaluated for antifungal activities. Quantitative bioassay was done using disc diffusion method and MIC done using broth dilution methods. The fungal isolates used for bioactivity testing were yeasts. Green tea crude extract mixture showed stronger inhibitory effect against the fungal strains tested than black tea crude extract mixture. There was a significant difference in zone of inhibitions (T=4.09, P<0.05). Zone of inhibition exhibited by green tea crude extracts (8.33±0.87 mm) were higher than black tea crude extracts (6.75±0.66 mm). The pattern of activity by tea crude extracts mixture against ATCC standard fungal strains and clinical isolates strains were similar. Candida tropicalis, Candida lusitaniae, Candida parapsilosis ATCC 22019, Cryptococcus neoformans ATCC 66031 and Candida famata were inhibited by green tea crude extracts mixture (IZD≥15±0.50 mm). Clinical isolates of Candida albicans (strain 5) showed susceptibility to C. sinensis green crude extracts mixture. The MIC of C. sinensis crude extracts mixture against fungal isolates tested ranged from 50 to 1.6 mg mL-1, with green tea crude extract mixture showing highest MIC on clinical fungal isolates. The studies on C. sinensis have shown remarkable antifungal activity and highlighted its significance as potential health products. Key words: Camellia sinensis, crude tea extracts, fungal species.