Levan polysaccharide from Erwinia herbicola protects osteoblast cells against lipopolysaccharide-triggered inflammation and oxidative stress through regulation of ChemR23 for prevention of osteoporosis

Osteoblast cell injury is a type of degenerative disorder characterized by osteolysis. Levan polysaccharide is an active component of Erwinia herbicola, which shows potential anti-inflammatory and antioxidant properties. However, the protective effects of levan on lipopolysaccharide (LPS)-induced inflammatory and oxidative stress injury in osteoblast cells as an in vitro model of osteolysis remain largely unknown. The present study aimed to explore the functions of levan in LPS-triggered inflammation and oxidative stress in osteoblast cells (MC3T3-E1). The protective effects of levan on LPS-induced inflammatory and oxidative stress responses in MC3T3-E1 cells were assessed by quantification of superoxide dismutase (SOD) and catalase (CAT) activity as well as enzyme-linked immunosorbent assay (ELISA) for determination of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Also, the key signaling pathway of ChemR23 was determined by qPCR analysis. Results showed that levan significantly alleviated LPS-induced deactivation of SOD and CAT activity. Levan also downregulated the expression of IL-6, TNF-α, and ChemR23 at mRNA level. These findings indicated that levan may protect MC3T3-E1 cells against LPS-triggered oxidative stress, and inflammation via regulation of ChemR23. This data may provide a potential basis for further clinical investigation of levan in the prevention and treatment of LPS-triggered bone resorption and osteolysis.