l-Arginine and allopurinol supplementation attenuates inflammatory mediators in human osteoblasts-osteoarthritis cells

This study investigated the synergistic effects of l-arginine and allopurinol on antioxidant and inflammatory mediators in human osteoblasts-osteoarthritis (HOb-OA) cells. The cells were treated with allopurinol (50-150 mg/kg bwt) and l-arginine (50-150 mg/kg bwt) for 72 h. Cell viability, catalase, superoxide dismutase (SOD), glutathione peroxidase (Gpx), reduced glutathione (GSH), lipid peroxidation, and the inflammatory markers interleukin 6 (IL-6), interleukin 1β (IL-1β), nuclear factor κB (NF-κB) and tumor necrosis factor alpha (TNF-α) were measured. The combined supplementation with allopurinol and l-arginine increased catalase, SOD, GSH, and Gpx, while it decreased lipid peroxidation, IL-6, IL-1β, and TNF-α. While TNF-α, IL-6, IL-1β, and NF-κB mRNA and protein expression were higher in control HOb-OA cells, the combined supplementation with allopurinol and l-arginine substantially reduced their expression in HOb-OA cells by >40%. In summary, combined supplementation with allopurinol and l-arginine might be very effective in osteoarthritis. A search for therapeutic agents that inhibit inflammation could help to prevent and manage osteoarthritis. However, further studies need to determine the biochemical and molecular mechanisms of these agents in osteoarthritis.