No abstract

We examined the viability and morphology of Candida albicans under experimental conditions after treatment with varying concentrations of cinnamaldehyde, the major component of cassia (Cinnamomum cassia), using XTT assay, fluorescent microscopy, scanning electron microscopy, and thin-section electron microscopy. At 10 μg/ml level, cinnamaldehyde inhibited mycelial growth, but did not affect the growth of yeast cells, metabolic activity, cell shape, or the ultrastructure of the cells. At 40 μg/ml level, cinnamaldehyde showed fungicidal activity accompanied by alteration of the membrane and interior of Candida cells. These findings indicate that cinnamaldehyde has both fungistatic and fungicidal activities against C. albicans and affects the structure of the cells.

We examined the effect of a clove (Syzygium aromaticum) administered by two different routes on Candida albicans growth. using a murine oral candidiasis model.When the clove preparation was administered into the oral cavity of Candida-infected mice. their oral symptoms were improved and the number of viable Candida cells in the cavity was reduced. In contrast. when the clove preparation was administered intragastrically. oral symptoms were not improved.but viable cell numbers of Candida in the stomach and feces were decreased. These findings demonstrate that oral intake of an herbal food. clove. may suppress the overgrowth of C. albicans in the alimentary tract including the oral cavity.

We examined the therapeutic effects of cinnamaldehyde and the potentiation of those effects with cassia and cinnamaldehyde when combined with the food additive methylcellulose against murine oral candidiasis. When 19.5 mg/ml of cinnamaldehyde was administered in the oral cavity of Candida infected mice, the oral symptoms were improved. Furthermore, when either a cassia or a cinnamaldehyde preparation in combination with methylcellulose was administered to oral candidiasis-inflicted mice, the therapeutic effects of cassia or cinnamaldehyde potentiated. Methylcellulose itself did not affect the oral symptoms or the viable number of C. albicans cells. GC/MS analysis showed that the dose of cinnamaldehyde remaining in the tongue tissue of mice treated with the cinnamaldehyde-methylcellulose mixture was higher than that in mice administered cinnamaldehyde alone, and also showed that cinnamaldehyde was not detected in the blood of any of the tested mice. These findings suggested that the combination of cassia or cinnamaldehyde and methylcellulose may be a useful prophylactic or therapeutic tool against oral candidiasis.

This study investigated the effects of cinnamaldehyde in combatting the hyphal growth of Candida albicans under varying concentrations, treatment times, and temperatures to determine the potential benefits of applying this substance to anti-Candida foods or gargles. From the results of pretreatment with cinnamaldehyde against Candida hyphae, we found that its inhibitory activity seemed to be strengthened in parallel with prolonged pretreatment time and a rise in temperature, and that pretreatment of 2,000 µg/ml for only 1 minute significantly inhibited the hyphal growth of C. albicans. We also demonstrated by XTT assay that pretreatment with cinnamaldehyde affected the metabolic activity of Candida hyphal cells. These findings suggest that a warm drink or mouthwash containing cinnamaldehyde might be a candidate as a prophylactic or therapeutic tool against oral Candida infection. Key words：Candida albicans, cinnamaldehyde, hyphal growth, crystal violet staining assay, XTT assay