Effects of the combination of hyaluronic acid and adelmidrol on plasma cytokines and nerve growth factor (NGF) in osteoarthritis (OA) rats. MIA-induced OA and tissue sample processing were carried out as detailed in the Methods section. Increased tumor necrosis factor alpha (TNF-α) (a), interleukin-1beta (IL-1β) (b), and NGF (c) plasma levels were detected in the MIA + solvent and MIA + 1.0% sodium hyaluronate groups after MIA administration. OA rats treated with the indicated doses of adelmidrol and HA exhibited a dose-dependent reduction in the plasma levels of all the measured parameters. Values are shown as mean ± SEM of 10 animals for each group. *P < 0.05 versus sham, °P < 0.05 versus MIA + vehicle.