Mechanism of Mongolian drug Naru-3 in initiation of neuroinflammation of neuropathic pain from MMP9/IL-1β signaling pathway / 中国中药杂志

Neuropathic pain(NP) has similar phenotypes but different sequential neuroinflammatory mechanisms in the pathological process. It is of great significance to inhibit the initiation of neuroinflammation, which has become a new direction of NP treatment and drug development in recent years. Mongolian drug Naru-3 is clinically effective in the treatment of trigeminal neuralgia, sciatica, and other NPs in a short time, but its pharmacodynamic characteristics and mechanism of analgesia are still unclear. In this study, a spinal nerve ligation(SNL) model simulating clinical peripheral nerve injury was established and the efficacy and mechanism of Naru-3 in the treatment of NPs was discussed by means of behavioral detection, side effect evaluation, network analysis, and experimental verification. Pharmacodynamic results showed that Naru-3 increased the basic pain sensitivity threshold(mechanical hyperalgesia and thermal radiation hyperalgesia) in the initiation of SNL in animals and relieved spontaneous pain, however, there was no significant effect on the basic pain sensitivity threshold and motor coordination function of normal animals under physiological and pathological conditions. Meanwhile, the results of primary screening of target tissues showed that Naru-3 inhibited the second phase of injury-induced nociceptive response of formalin test in mice and reduced the expression of inflammatory factors in the spinal cord. Network analysis discovered that Naru-3 had synergy in the treatment of NP, and its mechanism was associated with core targets such as matrix metalloproteinase-9(MMP9) and interleukin-1β(IL-1β). The experiment further took the dorsal root ganglion(DRG) and the stage of patho-logical spinal cord as the research objects, focusing on the core targets of inducing microglial neuroinflammation. By means of Western blot, immunofluorescence, agonists, antagonists, behavior, etc., the mechanism of Naru-3 in exerting NP analgesia may be related to the negative regulation of the MMP9/IL-1β signaling pathway-mediated microglia p38/IL-1β inflammatory loop in the activation phase. The relevant research enriches the biological connotation of Naru-3 in the treatment of NP and provides references for clinical rational drug use.

Role of JAK2/STAT3 signaling pathway in ginsenoside Re pretreatment in prevention of isoproterenol-induced acute myocardial ischemia / 中国药理学通报

Aim To observe the protective effect of ginsenoside Re pretreatment on rats with isoproterenol-induced acute myocardial ischemia via JAK 2/STAT3 signaling pathway .Methods SD rat model with acute myocardial ischemia was established using isoprotere-nol.Seventy-five rats were randomly divided into five groups: control group, model group , puerarin group (PUE), high dose group (Re-H, 20 mg· kg -1) and Re low-dose group ( Re-L, 10 mg kg -1 ) .The blood flow on the heart surface of rats in each group was ob-served by moor laser blood flow imaging system .The levels of CK , LDH, SOD, MDA and GSH in myocar-dium were measured by ELISA .The expressions of Bax and Bcl-2 proteins were detected by immunohistochem-istry.The expressions of JAK , p-JAK, STAT3 and p-STAT3 proteins were detected by Western blot .Re-sults Compared with the control group , the mean blood flow on the heart surface of rats in the model group significantly decreased , the levels of CK , LDH and MDA in the myocardium increased , the levels of GSH and SOD decreased , the ratio of Bcl-2/Bax de-creased ( P <0.05 ) , and the expression of JAK 2/STAT3 pathway related proteins was enhanced ( P <0.05 ) . The mean blood flow on the heart surface markedly increased , the levels of CK , LDH and MDA decreased , the level of GSH-Px increased , the ratio of Bcl-2/Bax increased, and the expression of JAK2/STAT3 pathway proteins evidently increased in the Re-H group compared with those of the model group ( P<0.05 ) .Conclusion Ginsenoside Re pretreatment has a good protective effect on the myocardium in rats with acute myocardial ischemia , which may be related to the activation of JAK2/STAT3 signaling pathway .