Fig. 5.

Effect of PEA on the expression of MMPs and TIMP-1 in the synovia of MIA-induced OA rats. MIA-induced OA rats were administered either PEA (50 or 100 mg/kg BW/day) or diclofenac (6 mg/kg BW/day) for 4 weeks. The total RNA was extracted from the synovia and reverse transcribed, followed by amplification using real-time PCR. Expression of target mRNA was normalized to that of Gapdh and represented relative to that of the NOR group. Each bar represents mean ± SEM (n = 10). ^*P < 0.01, ^**P < 0.05, and ^***P < 0.001 significantly different from the NOR group. ^#P < 0.01, ^##P < 0.05, and ^###P < 0.001 significantly different from the CON group. PEA palmitoylethanolamide, OA osteoarthritis, MIA monosodium iodoacetate, MMP matrix metalloproteinase, TIMP-1 tissue inhibitor of metalloproteinase-1, NOR normal control group (injected with saline + treated with phosphate-buffered saline (PBS)), CON control group (injected with MIA + treated with PBS), PEA50 or PEA100 50 or 100 mg/kg body weight (BW)/day PEA-treated group (injected with MIA + treated with 50 or 100 mg of PEA/kg BW/day), DiC positive control group (injected with MIA + treated with 6 mg of diclofenac/kg BW/day)