Abstract: Objective To investigate the effect of Compound Shougong powder (CSP) on the pain sensitization in rats with bone cancer pain through tumor necrosis factor-α (TNF-α) signaling pathway. Methods A rat model of lung cancer bone metastases pain was established by injecting Lewis lung cancer cells. Rats were randomly divided into 6 groups: model group, positive control group ( Voltaren, 0. 1 g / kg), CSP low-dose group ( CSP-L, 20 mg / kg), CSP medium-dose group (CSP-M, 40 mg / kg), CSP high-dose group (CSP-H, 80 mg / kg), and the sham operation group, 10 rats in each group. After the intervention, the paw withdrawal mechanical threshold (PWMT) of the rats was detected, and the paw withdrawal thermal latency (PWTL) in rats was detected by the automatic thermal pain tester. The levels of TNF-α, IL-1β and IL-6 in serum were detected by ELISA. Western blotting was performed to detect the expression levels of monocyte chemoattractant protein-1 (MCP-1) and TNF-α in spinal cord tissues of rats in each group. Results The levels of IL-1β, IL-6, TNF-α and MCP-1 in the model group were significantly increased when compared with those in the sham operation group, while the values of PWMT and PWTL were significantly decreased (P<0. 05). The levels of IL-1β, IL-6, TNF-α and MCP-1 in the CSP-L group, CSPM group and CSP-H group were significantly decreased when compared with those in the model group, while the values of PWMT and PWTL were significantly increased (P<0. 05). No obvious differences in the above indexes were found between the CSP-H group and the positive control group (P > 0. 05). Conclusion CSP may alleviate the pain response in rats with lung cancer bone metastases pain and exert analgesic effect by inhibiting the expression of TNF-α and other inflammatory factors.

Key words: Compound Shougong powder, TNF-α, lung cancer, bone cancer pain, pain sensitization