Baicalin alleviates osteomyelitis by regulating TLR2 in the murine model

Osteomyelitis is an inflammation of bone caused by invading organisms. TLR2, inflammatory cytokines and mitogen-activated protein kinase (MAPK) signaling pathway are involved in osteomyelitis. Baicalin, the major active constituent of the isolated root of Scutellaria lateriflora Georgi, has been shown to have anti-inflammatory effects. In this study, the potentials of baicalin against osteomyelitis were evaluated. We treated mice and MC3T3-E1 cells with baicalin together with Staphylococcus aureus infection, and then analyzed the mice bone destruction, the expressions of TLR2 and osteogenic marker, the serum levels of proinflammatory factors and activation of MAPK signaling pathway. We also knocked down TLR2 by shRNA in MC3T3-E1 cells and detected the role of TLR2 in baicalin mediated inhibition of osteomyelitis. It was found that baicalin alleviated bone destruction in osteomyelitis. Baicalin decreased TLR2, alkaline phosphatase, osteopontin and collagen type I expressions. Baicalin decreased serum levels of proinflammatory factors IL-1β, IL-6 and CRP. Baicalin inhibited activation of MAPK signaling pathway. The inhibition of osteomyelitis by baicalin depended on TLR2 inhibition. In summary, baicalin is able to alleviate osteomyelitis by regulating TLR2.