Investigation on the inflammation network mechanisms of Wutou decoction acting on neuropathic pain / 药学学报

ABSTRACT

Wu-tou decoction (WTD) was originally recorded in the synopsis of the golden chamber and it had been widely used for the treatment of neuropathic pain (NP) with exact therapeutic efficacy. However, the underlying molecular mechanisms still remain unclarified. Thus, in this research, we aimed at clarifying the underlying molecular mechanisms of WTD against NP by combining network analysis and experimental validation based on the spinal nerve ligation (SNL) model. Firstly, the network analysis indicated that key targets of WTD were significantly involved in the MAPK signaling pathway (P = 4.04E-12) and four important components of the above pathway, AKT kinase (AKT), MAP kinase kinase 4 (MKK4), c-Jun N-terminal kinase (JNK) and transcription factor AP-1 (JUN) had been reported to play a vital role in neuroinflammation during the disease process of NP. Then, experimental validation results proved that WTD markedly reduce the severity of mechanical allodynia (P<0.01) and cold hypersensitivity (P<0.05) of SNL rats. In addition, Western blot results provided evidence that the phosphorylated protein expression levels of AKT, MKK4, JNK and JUN in the superficial lamina of spinal cord of SNL rats were markedly increased (P<0.001), and WTD could improve the phosphorylated protein expression level of AKT (P<0.001) which was reported to be nerve protective and attenuate the phosphorylated protein expression levels of MKK4, JNK and JUN (P<0.01) which were closely involved into neuroinflammation. In conclusion, this study indicated that WTD might exert anti-hyperalgesia action through the inhibition of neuroinflammation mediated by AKT-MKK4-JNK-JUN which belong to the MAPK signaling pathway. These findings also provided scientific evidences that WTD might be a promising candidate for NP. Animal experiments in this study were approved by the Ethics Committee of Experimental Animals of the China Academy of Chinese Medical Sciences.