Inhibitory effect of clove methanolic extract and eugenol on dendritic cell functions

• Main Authors: Ching-Hsiung Lin, Sheng Hao Lin, Chi-Chen Lin, Yi-Chen Liu, Chao-Jung Chen, Ching-Liang Chu, Hui-Chi Huang, Ming-Kuem Lin
• Format: Article
• Language: English
• Published: Elsevier 2016-12-01
• Series: Journal of Functional Foods
• Subjects: Clove; Eugenia caryophyllata; Eugenol; Dendritic cell; Immunity; Hypersensitivity
• Online Access: http://www.sciencedirect.com/science/article/pii/S1756464616303048

Caryophyllata Flos or clove is widely used as a condiment and in Chinese medicine. It reportedly helps relieve asthma and allergies; however, the underlying mechanisms remain unclear. In particular, the mechanism affecting dendritic cells (DCs), which play a critical role in the immune response, remains unknown. In this study, we examine the effects of Caryophyllata Flos methanolic extract (CFME) and its major compound, eugenol, on DC functions. Our results showed that CFME and eugenol significantly inhibited DC activation and maturation. The IC50s of CFME and eugenol were approximately 25 µg/mL and 50 µM, respectively. CFME and eugenol halted T-cell proliferation. Contact hypersensitivity responses were inhibited in mice cosensitized with either CFME or eugenol. We demonstrated for the first time that clove and its major active ingredient, eugenol, exhibited a significant immunosuppressive effect on DC functions, revealing that clove is a functional food that can ameliorate chronic inflammation and autoimmunity.