To evaluate the anti-inflammatory effects of clinically relevant naproxen sodium (Nx) concentrations on human monocyte-derived macrophages in a controlled in vitro system and human primary synovial fluid (SF) cells.
Using phorbol 12-myristate 13-acetate, THP-1 human monocytic cells were differentiated into mature monocyte-derived macrophages in vitro then treated with Nx pre- or post-activating an inflammatory response with lipopolysaccharide (LPS) and hyaluronan (HA) fragments (n = 8/group). Cell culture supernatants were assessed for NF-κB activity and prostaglandin E
Compared to placebo treatment of THP-1 cells, low dose Nx (corresponding 27.5-440 mg/L orally) added both pre- and post-activation with LPS/HA, significantly reduced NF-κB activity and PGE2: mean reduction to 73%, 61%, 17% and 10% of placebo, respectively. LPS/HA treatment of primary OA SF cells significantly increased the number of IL-1β producing primary monocytes and macrophages, and by 24 h the overall production of secreted cytokines (IL-1β, IL-6, IL8, and TNF-α). Low dose Nx reduced the percentage of IL-1β producing primary monocytes and macrophages.
LPS/HA induced inflammation of THP-1 monocytic and primary human SF cells. Low dose Nx both prevented and reduced inflammatory responses of a human monocytic cell line and reduced IL-1β production by primary human SF monocytes and macrophages.