【Animal experiment】-The effect of bee venom on TrkA and TRPV1 in dorsal root ganglia of rats with collagen-induced arthritis inflammatory pain

      Objective: To study the effect of bee venom on TrkA and TRPV1 pain signaling molecules in collagen-induced arthritis (CIA) rats.

  Method: Divided into normal control group, model group and bee venom group (BV, 3mg/mL). Use adult Wistar rats, collagen II + IFA 0.2 mL to build the model. The BV group was administered within 14 days (up to 21 days) after establishing the model. Record the plantar and plantar thickness, pain threshold and joint swelling score of each group. We used the dorsal root ganglia to observe the expression of TRPV1 in pathological sections, and evaluated the expression of bee venom with TrkA, and performed ankle joint intervention in CIA rats.

  Result: The model began to swell on day 10, all signs of CIA appeared within 14 days, and the paw thickness and joint swelling scores gradually increased overall. Stable for 14 days. The BV group was treated with 0.3 mg bee venom for 7 days. The foot and joint swelling of the BV group was lower than that of the model group. Pain threshold (seconds): normal control group 15.47±0.35, model group 10.90±0.10, BV group 13.14±0.18. Immunohistochemistry TRPV1 positive cell rate (%): normal control group 11.40±1.48, model group 44.47±4.38, BV group 21.60±2.20. TrkA expression (gray value) observed by Western blot: normal control group 1.59±0.04, model group 4.53±0.21, BV group 2.46±0.17.

   Conclusion: Bee venom injection may reduce the expression levels of DRG signaling molecules TrkA and TRPV1 in rats with inflammatory pain. This may be one of the anti-inflammatory and analgesic signaling pathways and provides new enlightenment for the treatment of rheumatoid arthritis with bee venom.