2. Academic Validation
  3. SZAP exerts analgesic effects on rheumatalgia in CIA rats by suppressing pain hyperalgesia and inhibiting TRPV1 and P2X3

SZAP exerts analgesic effects on rheumatalgia in CIA rats by suppressing pain hyperalgesia and inhibiting TRPV1 and P2X3

  • J Ethnopharmacol. 2022 Feb 10;284:114780. doi: 10.1016/j.jep.2021.114780.
Jie Wang 1,  Wen Wen 1,  Daoyin Gong 2,  Qi Chen 1,  Ping Li 1,  Panwang Liu 1,  Fushun Wang 3,  Shijun Xu 4
Affiliations

Affiliations

  • 1 School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, PR China; Institute of Meterial Medica Integration and Transformation for Brain Disorders, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, PR China.
  • 2 Department of Pathology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China.
  • 3 Institute of Brain and Psychological Science, Sichuan Normal University, Chengdu, Sichuan, 610000, China.
  • 4 School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, PR China; Institute of Meterial Medica Integration and Transformation for Brain Disorders, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan, 611137, PR China; State Key Laboratory of Southwestern Chinese Medicine Resources, Chengdu, Sichuan, 611137, PR China. Electronic address: xushijun@cdutcm.edu.cn.
PMID: 34728318 DOI: 10.1016/j.jep.2021.114780
Abstract

Ethnopharmacological relevance: ShexiangZhuifeng Analgesic Plaster (SZAP) is a traditional Chinese medicine and transdermal formulation composed of many Chinese herbs and active compounds. SZAP was recently approved by the China Food and Drug Administration for the treatment of pain associated with osteoarticular diseases and is preferred by most rheumatoid arthritis patients in China. However, its mechanism has not been elucidated in detail.

Aim of the study: We sought to determine the analgesic effect of SZAP in collagen-induced arthritis (CIA) rats and explore the underlying mechanisms of pain transmission, such as via the TRPV1 and P2X3 receptors.

Methods: After CIA was established, rats were treated with SZAP for 7 days. Paw thickness, arthritis score, and haematoxylin and eosin staining were used to evaluate the effectiveness of SZAP. Paw withdrawal threshold (PWT) and tail-flick latency (TFL) were used to estimate the analgesic effect of SZAP. The levels of PGE2, BK, 5-HT, SP, and CGRP in the serum and synovium were determined using ELISA kits, and ATP in the synovium was measured using HPLC. The expression of TRPV1 and P2X3 in the DRG was detected using western blotting and immunofluorescence. TRPV1 and P2X3 agonists were further used to determine the analgesic effects of SZAP on CIA rats based on PWT and TFL.

Results: SZAP not only significantly ameliorated arthritis scores and paw thickness by improving the pathological damage of synovial joints, but also remarkably alleviated pain in CIA rats. Further, treatment with SZAP significantly reduced peripheral 5-HT, PGE2 BK, SP, CGRP, and ATP. Additionally, the expression of TRPV1 and P2X3 in the DRG was markedly downregulated by SZAP. Interestingly, the analgesic effect of SZAP was weakened (reduction of PWT and TFL) when TRPV1 and P2X3 were activated by capsaicin or α,β-meATP, respectively.

Conclusion: SZAP ameliorates rheumatalgia by suppressing hyperalgesia and pain transmission through the inhibition of TRPV1 and P2X3 in the DRG of CIA rats.

Keywords

P2X3; Pain hyperalgesia; Rheumatalgia; ShexiangZhuifeng analgesic plaster; TRPV1.

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