Dalbergiones lower the inflammatory response in oral cells in vitro

OBJECTIVES: Periodontitis is a global health burden that underlines the demand for anti-inflammatory treatment. Dalbergia melanoxylon being a rich source of flavonoids has been widely used in traditional medicine but the potential anti-inflammatory activity of its dalbergiones remains to be shown. MATERIAL AND METHODS: We have isolated 3′-hydroxy-4,4′-dimethoxydalbergione, 4-methoxydalbergione, and 4′-hydroxy-4-methoxydalbergione from Dalbergia melanoxylon and tested their potential anti-inflammatory activity. RESULTS: All dalbergiones are potent inhibitors of an LPS-induced inflammatory response of RAW 264.7 macrophages. This is specified by IL1β and IL6 production, and the p65 nuclear translocation. Consistently, in primary macrophages, the dalbergiones caused an M1-to-M2 polarization switch indicated by the decreased ration of IL1β and IL6 versus arginase 1 and YM1 expression. To implement oral cells, we have used gingival fibroblasts exposed to IL1β and TNFα. Consistently, all dalbergiones reduced the expression of IL6 and IL8 as well as the nuclear translocation of p65. CONCLUSION: These findings increase the accumulating knowledge on dalbergiones and extend it towards its capacity to lower the inflammatory response of oral cells. CLINICAL RELEVANCE: These findings are another piece of evidence that supports the use of herbal medicine to potentially lower inflammatory events related to dentistry.