ABSTRACT
Periodontitis is a progressive chronic inflammatory disease and a major cause of tooth loss in humans. As a withanolides, withaferin A (WA) is known to exhibit strong antiinflammatory activity. The present study examined whether WA inhibited inflammatory responses in macrophages in response to two representative periodontal pathogens, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans. Murine bone marrowderived macrophages (BMDMs) were used in this study and cytokine production in culture supernatants was measured by enzymelinked immunosorbent assays. Western blot analysis was performed to determine the activation of nuclear factorκB and mitogenactivated protein kinases (MAPKs) and the expression of inducible nitric oxide synthase (iNOS), tolllike receptor (TLR) 2 and TLR4. The production of nitric oxide (NO) was determined by the Griess reaction. WA treatment was shown to decrease interleukin (IL)6 and tumor necrosis factor (TNF)α production in BMDMs in response to F. nucleatum and A. actinomycetemcomitans in a dosedependent manner. The phosphorylation of IκBα and MAPKs (p38, extracellular signalregulated kinases and cJun Nterminal kinases) induced by F. nucleatum and A. actinomycetemcomitans was also inhibited by WA. F. nucleatum and A. actinomycetemcomitans induced iNOS expression and NO production in BMDMs, which was inhibited by WA in a dosedependent manner. WA also reduced endogenous and induced expression of TLR2 and TLR4 in these cells. These results suggest that WA may be a potential therapeutic agent or preventive additive for periodontitis control.
