Anti-fungal Activities of Amine Oxide against Candida albicans

Amine Oxides (AO) are amphoteric surfactants, exhibiting antimicrobial activity against various microorganisms.  Candida albicans, a fungal pathogen associated with denture stomatitis. The effect of amine oxides on fungal pathogens and biofilm deserved to be studied. Objective: The study was designed to investigate the effect of AO on the growth of C. albicans, and investigate their fungicidal activity against fresh and bio-film grown fungal cells on polymethyl methacrylate [PMMA] substrate. Methods: C. albicans (ATCC 44505) was cultured in Sabourad's broth (SAB) and suspended to a concentration of 1x10⁷cells/ml, and were mixed with equal amount of serially diluted AO (Sigma) and incubated for 30 min. The viability of fungi was determined by the XTT (Roche Labs) proliferation assay. Biofilm cells were prepared by immersing the PMMA discs in a suspension of C.albicans (1x10⁷ cells) and incubated for 3 h to adhere. The discs were washed and then left immersed in fresh SAB supplemented with 50mM glucose for another 3 days. Discs were then gently washed and the cells present on the discs were scrapped and used them as bio-film grown cells. Results: AO had fungicidal activity which was concentration-dependent. AO (0.006%) inhibited the growth of C. albicans by more than 60%. However, a concentration of 0.09% was required to obtain 60% inhibition of biofilm-grown cells. AO (0.05%) also inhibited the formation of C. albicans biofilm on PMMA discs and also found to remove more than 95% of biofilm that was pre-formed on the discs. Conclusion: The results demonstrated the anti-fungal activity of AO and shown also to inhibit biofilm formation on PMMA discs. The use of AO may play an important role in preventing denture-induced stomatitis, by its fungicidal activity against fresh and biofilm grown C. albicans.