Treatment with conditioned culture media with human mesenchymal stem cells on reserpine-induced thermal fibromyalgia model in rats

Background and Aims: Fibromyalgia (FM) is a chronic pain syndrome affected by the hippocampal function. Mesenchymal stem cells-conditioned medium (MSC-CMs) has shown antioxidant and neuroprotective potentials in treating various diseases. The present study aimed to investigate the efficacy of MSC-CMs on the thermal treatment of reserpine-induced FM and evaluate the concentration changes of tumor necrosis factor-alpha (TNF-α) in the hippocampus of rats under these conditions. Materials and Methods: 220 g. Animals received reserpine (1 mg/kg) in the FM groups, and subcutaneous injection of normal saline in other groups, once a day for 3 consecutive days. Then, the rats received MSC-CM (0.3 and 0.5 mg/ml protein content, intraperitoneally) once a week for three weeks. The thermal pain threshold of mice was evaluated using tail flick and hot plate tests at the beginning and end of the experiments. TNF-α concentration in the hippocampus was determined by an ELISA kit at the end of the experimental period. Results: The thermal pain threshold of rats in the FM group decreased significantly (P<0.01) in both pain tests compared to that of the control group. A significant increase (P<0.01) was observed in the level of TNF-α in the hippocampus of rats in the FM group compared to that of the control group. Treatment with MSC-CMs significantly reduced reserpine-induced pain and hippocampal TNF-a concentration despite the effect of fresh and conditioned medium on control rats. Conclusion: Treatment with MSC-CMs could control thermal pain in the rat model of reserpine-induced fibromyalgia by controlling the TNF-a level in the hippocampus.