Alkannin inhibits CCL3 and CCL5 production in human periodontal ligament cells.

Alkannin, which is found in Alkanna tinctoria, a member of the borage family, is used as a food coloring. Alkannin has recently been reported to have certain biological functions, such as anti-microbial and anti-oxidant effects. It is known that CC chemokine receptor (CCR) 5-positive leukocytes contribute to alveolar bone resorption in periodontal lesions. The aim of this study was to examine whether alkannin inhibits the production of CC chemokine ligand (CCL) 3 and CCL5, which are CCR5 ligands, in human periodontal ligament cells (HPDLC). Interleukin (IL)-1β induced CCL3 and CCL5 production in HPDLC. Alkannin inhibited IL-1β-mediated CCL3 and CCL5 production in HPDLC in a dose-dependent manner. Moreover, we revealed that alkannin suppressed inhibitor of kappa B-α degradation in IL-1β-stimulated HPDLC. In addition, a nuclear factor (NF)-κB inhibitor significantly inhibited CCL3 and CCL5 production in IL-1β-stimulated HPDLC. These results demonstrate that alkannin inhibits CCR5 ligand production in IL-1β-stimulated HPDLC by attenuating the NF-κB signaling pathway.