Effects of Parecoxib on Pain Threshold and Inflammatory Factors IL-1β, IL-6 and TNF-𝜶 in Spinal Cord of Rats with Bone Cancer Pain

To investigate the effects of parecoxib on pain threshold and inflammatory factors interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in spinal cord of rats with bone cancer pain.An experimental study.Department of Oncology, Shengjing Hospital of China Medical University, China, from March 2017 to May 2018.Twenty-four healthy female Sprague-Dawley rats were selected and the bone cancer pain model was inoculated with W256 breast cancer cell into the bone marrow. Rats with bone cancer pain were randomly divided into the model group and the parecoxib group on the 7th day postoperation, with 12 rats in each group. Another 12 rats were taken as the control group. Rats in the parecoxib group were given intraperitoneal injection of parecoxib (8 mg/kg) for 10 consecutive days since the 15th day after operation. Mechanical pain threshold, thermal pain threshold, and the levels of inflammatory factors IL-1β, IL-6 and TNF-α in spinal cord of rats in each group were compared.On the 14th postoperative day, mechanical pain threshold and thermal pain threshold of rats in the model group and the parecoxib group were significantly decreased compared with those in the control group (p<0.001). After 5 and 10 days of administration, mechanical and thermal pain threshold of rats in the parecoxib group were significantly higher than those in the model group and the control group (p<0.001). After 10 days of administration, levels of IL-1β, IL-6 and TNF-α in spinal cord of the model group were higher than those of the control group (p<0.001); and levels of IL-1β, IL-6 and TNF-α in spinal cord of the parecoxib group were significantly lower than those in the model group and the control group (p<0.001).Parecoxib can alleviate hyperalgesia in rats with bone cancer pain, increase pain threshold and inhibit the up-regulation of inflammatory factors in the spinal cord. Parecoxib may achieve analgesic effects by down-regulating the expression of IL-1β, IL-6 and TNF-α in the spinal cord.