Bifidobacterium longum CBi0703 lysate modulates oxidative stress induced apoptosis and cartilage related gene expression in SW1353 chondrocytes: in vitro insights into the gut joint axis in Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage degradation, inflammation, and impaired joint function. This in vitro study evaluates the effects of Bifidobacterium longum CBi0703 lysate, alone and in combination with clinically used OA nutraceuticals, on viability, apoptosis and cartilage related gene expression in human SW1353 chondrocytes exposed to hydrogen peroxide induced oxidative stress, an OA like condition. SW1353 chondrocytes were exposed to H₂O₂ (50 µM, 2 h) to induce an OA-like state, followed by a 22-h treatment with B. longum CBi0703 lysate individual nutraceuticals (vitamin C, collagen, chondroitin sulphate, glucosamine sulphate, Chondro Mix, natural eggshell membrane (NEM)), or their combinations. Cell viability, proliferation, apoptosis, and expression of catabolic and anabolic genes were assessed.B. longum CBi0703 and selected combinations enhanced chondrocyte proliferation, reduced caspase activation and modulated key catabolic (MMP1, MMP13, ECM1, GBL1) and anabolic (COL2A1, SOX9, AGC1, TIMP1) markers compared with the OA-induced vehicle. The combination with vitamin C upregulated SOX9 and TIMP1 while downregulating COL1A1 and ECM1; the combination with chondroitin sulphate increased COL2A1 expression; and the combination with glucosamine sulphate reduced late apoptosis. These results provide mechanistic insight into the potential chondroprotective actions of B. longum CBi0703 in an OA like in vitro model and support further preclinical and clinical studies to assess its role as an adjunct to established OA treatments.