Anti-swelling and Analgesic Mechanism of Jianpi Tongluo Prescription from MAPKs Signaling Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo observe the anti-swelling and analgesic effects of Jianpi Tongluo prescription （JPTL） and to explore its mechanism initially. MethodA total of 120 ICR mice were divided into normal group， model group， JPTL low-， medium- and high-dose groups （5， 10， 20 g·kg-1） and positive drug （celecoxib， 0.03 g·kg-1） group， with 10 in each group （po，once a day）. Complete freund's adjuvant （CFA） was used to induce the model of chronic inflammatory pain， and xylene-induced ear swelling test， hot plate test and acetic acid writhing test were performed to observe the anti-swelling and analgesic effects of different doses of JPTL in these four acute and chronic models. Further， enzyme-linked immunosorbent assay （ELISA） was used to detect the expressions of prostaglandin E2 （PGE2）， interleukin-1β （IL-1β）， interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α） in serum and inflammatory paw of mice with chronic inflammatory pain， and the expressions of aquaporin 1 （AQP1）， aquaporin 3 （AQP3）， cyclooxygenase 1 （COX1）， cyclooxygenase 2 （COX2） and mitogen-activated protein kinases （MAPKs） in inflammatory paw were detected by Western blot， to explore the preliminary mechanism of JPTL. ResultCompared with the conditions in the normal group， there was a significant increase in the ear swelling of xylene-induced model mice， a shortened paw withdrawal latency in the hot plate test （P<0.01）. Compared with the model group， JPTL remarkably increased the inhibition rate of xylene-induced ear swelling （P<0.05， P<0.01）， prolonged the latency period of writhing caused by acetic acid and reduced the number of writhing （P<0.05， P<0.01）. Compared with normal group, the degree of feet swelling in chronic inflammatory pain mice was significantly increased， the threshold of mechanical pain was decreased and the threshold of cold pain was increased （P<0.05， P<0.01）， the protein contents of AQP1 and AQP3 in inflammatory feet were increased， and the contents of IL-1β， IL-6， TNF-α， PGE2 and COX2 in inflammatory feet were increased in serum and/or inflammatory feet. The protein expression levels of p-p38 MAPK， p-JNK and p-ERK in inflammatory feet were increased （P<0.01）. Compared with the model group， JPTL relieved paw swelling of mice with chronic inflammatory pain， elevated mechanical withdrawal threshold while decreased cold withdrawal threshold， with analgesia lasting for 4 h and the optimal time point for analgesia being 2 h after administration （P<0.05， P<0.01）. Moreover， JPTL down-regulated AQP1， AQP3， COX2， p-p38 MAPK， p-JNK and p-ERK in inflammatory paw of mice with chronic inflammatory pain and reduced IL-1β， IL-6， TNF-α， and PGE2 in serum and/or inflammatory paw， but it had no significant effect on COX1 （P<0.05， P<0.01）. ConclusionJPTL has anti-swelling and analgesic effects， and its mechanism is related to inhibiting the production of cytokines and inflammatory mediators via the down-regulation of MAPKs signaling pathway， which provides an experimental basis for the clinical application of JPTL.