[Oral health care by utilizing food function].

We examined the effects of spices and herbs on Candida albicans to develop therapeutic tools against oral diseases such as oral candidiasis. C. albicans, a dimorphic fungus, is a component of the healthy human microbial flora. However, the excessive overgrowth of C. albicans causes oral candidiasis, and the symptoms, accompanied by severe inflammation, reduce the quality of life of elderly people. We found that spices such as clove (Syzygium aromaticum) and cassia (Cinnamomum aromaticum) exhibit inhibitory activity against Candida mycelial growth and show therapeutic efficacy in a murine oral candidiasis model. Our studies also demonstrated that the inhibitory activity of cinnamaldehyde was strengthened in parallel with a prolonged treatment time. Furthermore, when cinnamaldehyde in combination with methylcellulose was administered to the model mice, the therapeutic effect was potentiated. Here, we summarize up-to-date findings on how to use spices and herbs on a daily basis to improve or prevent oral problems such as oral candidiasis with the presentation of our recent data.

Therapeutic effects of cinnamaldehyde and potentiation of its efficacy in combination with methylcellulose on murine oral candidiasis.

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 19.5mg/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.

Therapeutic effects on murine oral candidiasis by oral administration of cassia (Cinnamomum cassia) preparation.

We examined the effects of spices and herbs on Candida albicans growth using in vitro assay and therapeutic activity of some selected herbal preparations against murine oral candidiasis. All tested samples: lemongrass (Cymbopogon citratus), lemon balm (Melissa officinalis), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), roselle (Hibiscus sabdariffa), green tea (Camellia sinensis), and cassia (Cinnamomum cassia) inhibited Candida mycelial growth in vitro. The results of this assay showed that the anti-Candida activity of lemongrass, green tea, and cassia is stronger than that of the other tested herbs. Oral administration of lemongrass or green tea did not result in significant improvement in the murine oral candidiasis, while the administration of cassia improved the symptoms and reduced the number of viable Candida cells in the oral cavity. The results of in vitro Candida growth assay including GC/MS analysis suggested that cinnamaldehyde in the cassia preparation was the principal component responsible for the inhibitory activity of Candida mycelial growth. These findings suggest that oral intake of a cassia preparation is a clinical candidate for a prophylactic or therapeutic tool against oral Candida infection.

Protection of oral or intestinal candidiasis in mice by oral or intragastric administration of herbal food, clove (Syzygium aromaticum).

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.