Marein prevented LPS-induced osteoclastogenesis by regulating the NF-κB pathway in vitro
Abstract Gram-negative bacterial infection causes many bone diseases such as osteolysis, osteomyelitis and septic arthritis. Lipopolysaccharide (LPS), a bacteria product, played an important role in this process. Drugs that inhibited LPS-induced osteoclastogenesis were urgently needed for the prevention of bone destruction in infective bone diseases. Marein, a major bioactive compound of Coreopsis.tinctoria, which possesses anti-oxidative, anti-inflammatory, anti-hypertensive, anti-hyperlipidemic and anti-diabetic effects. In this study, the effect of marein on RAW264.7 cells was measured by CCK-8 assay; TRAP staining was used to determine osteoclastogenesis; the levels of osteoclast-related genes and NF-κB-related proteins were analyzed by WB; the levels of pro-inflammatory cytokines were quantified by ELISA. Our results showed that marein inhibited LPS-induced osteoclast formation from osteoclast precursor RAW264.7 cells. The effect of marein was related to its inhibitory function on expressions of pro-inflammatory cytokines and osteoclast-related genes including RANK, TRAF6, MMP-9, CK and CAⅡ. Besides, marein treatment could inhibit LPS-induced activation of NF-κB signaling pathway in RAW264.7 cells. Meanwhile, inhibition of NF-κB signaling pathway decreased the formation of osteoclasts and expression of pro-inflammatory cytokines which were LPS-induced. Collectively, marein could prevent LPS-induced osteoclast formation in vitro by regulating NF-κB signaling pathway. These findings provided evidence that marein might be beneficial as a valuable choice for the prevention and treatment of bacteria-induced bone destruction disease, and gave new insights for understanding its possible mechanism.