Effect of Zhongyi paste on inflammatory pain in mice by regulation of the extracellular regulated protein kinases 1/2–cyclooxygenase-2–prostaglandin E₂ pathway

Abstract

Background: Zhongyi paste is a traditional Chinese medicine herbal paste that is externally applied to reduce inflammation and relieve pain. Methods: An acute foot swelling inflammation model in C57BL/6J mice was established by carrageenan-induced pathogenesis. Zhongyi paste raised the pain threshold and also reduced the degree of swelling in mice with carrageenan-induced foot swelling. Results: Analysis indicated that serum tumor necrosis factor-alpha, interleukin-1 beta, and prostaglandin E 2 (PGE 2) cytokine levels and PGE 2 levels in the paw tissue of the mice were decreased by Zhongyi paste treatment. The quantitative polymerase chain reaction and western blot results showed that Zhongyi paste downregulated the mRNA and protein expression of extracellular signal-regulated kinase 1/2 (ERK1/2), and cyclooxygenase-2 (COX-2), and also downregulated the mRNA expression of PGE 2. At the same time, the Zhongyi paste exerted a stronger effect as an external drug than that of indomethacin, which is an oral drug, and voltaren, which is an externally applied drug. Conclusions: Our results indicated that Zhongyi paste is a very effective drug to reduce inflammatory swelling of the foot, and its mechanism of action is related to regulation of the ERK1/2-COX-2-PGE 2 pathway.

Anti-Inflammatory Activities of Arnica montana Planta Tota versus Flower Extracts: Analytical, In Vitro and In Vivo Mouse Paw Oedema Model Studies

“…Carrageenan is a well-acknowledged pro-inflammatory agent used to initiate an acute inflammatory response upon injection into the footpad of rodents [ 34 , 35 , 36 ]. This carrageenan-induced paw oedema animal model is the experimental system of choice for evaluating the anti-inflammatory effect of drugs or natural products such as A. montana extracts.…”

“…Considering a recommended average application of 2 mg/cm 2 , three to five times a day, an amount of 1.8 to 3 mg Arnicae planta tota would be applied locally, using Arnica 30% ointment (compared to the 3 to 30 mg Arnicae planta tota applied in the mouse model of acute inflammation, described in this study). In addition to validating its use in preventing local inflammation (i.e., following a pre-treatment protocol, as described in this study), it would also be interesting to evaluate the potential benefit of the topical application of Arnicae planta tota to treat local inflammation (i.e., following induced inflammation), as shown for other natural products in the paw oedema mouse model [ 36 ].…”