[Lycium barbarum polysaccharide inhibits NF-κB pathway to reduce the level of inflammatory cytokines in osteoarthritis chondrocytes].

Objective To investigate the effect of Lycium barbarum polysaccharide (LBP) on the proliferation and immune-related cytokines in osteoarthritis (OA) chondrocytes. Methods We isolated chondrocytes from OA samples, and then detected cell proliferation of OA chondrocytes treated with LBP at 0, 100, 200, 400 and 800 μg/mL by MTT assay. OA chondrocytes were treated with 400 μg/mL LBP which was determined to be the optimal concentration by MTT assay. Real-time fluorescence quantitative PCR and Western blot analysis were performed to detect the expression of induced nitric oxide synthase (iNOS), growth transformation factor beta (TGF-β) and nuclear factor-κBp65 (NF-κBp65). And the levels of interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) in the supernatant were detected by ELISA. Results Cell viability of OA chondrocytes treated with LBP at 200, 400 or 800 μg/mL was significantly lower than that at 0 μg/mL, and cell viability of 400 μg/mL group and 800 μg/mL group was lower than that of 200 μg/mL group. There was no significant difference in the cell viability between the 400 μg/mL group and 800 μg/mL group. So 400 μg/mL LBP was used for subsequent experiments. Compared with the control group, the levels of IL-1β and TNF-α in the supernatant of OA chondrocytes after treated with 400 μg/mL LBP decreased; the expression of iNOS mRNA and protein were down-regulated; the expression of TGF-β was up-regulated; and the expression level of NF-κBp65 protein was reduced. Conclusion LBP could reduce the levels of immune-related cytokines in OA chondrocytes and inhibit the NF-κB signaling pathway, which is instrumental in improving the OA injury.