The intervention mechanism of emodin on TLR3 pathway in the process of central nervous system injury caused by herpes virus infection.

Background and purpose: To investigate the effect of Emodin on the inflammatory response of brain tissue and the expression of the TLR3 pathway in mice with herpes virus encephalitis. Method: Twenty male BALB/c mice were randomly divided into the NS group, HSV-1 group, HSV-1 + Emodin group and HSV-1 + ACV group. The histopathological features and the effect of TLR3 expression were observed by staining and immunohistochemistry (IHC) respectively. The gene expression of TLR3, trif, TRADD, TRAF6, traf3, p38, Nemo and IRF3 was detected by polymerase chain reaction (PCR). The protein production of TLR3 and its downstream molecules was detected by Western blot. The expression of IL-6, TNF-α and IFN-β in the brain tissues was detected by ELISA. Result: Compared to the HSV-1 group, the pathological changes (inflammatory cell infiltration, necrotic temporal lobe and massive hemorrhage) were not as obvious as those in the HSV-1+emodin and HSV-1+ACV groups. The TLR3 staining increased significantly in the HSV-1 groups and decreased in the HSV-1 + emodin group. Compared with the NS group, the mRNA expression of TLR3, TRIF, TRADD, TRAF6, traf3, p38, NEMO and IRF3 decreased by 20%–60% in the HSV-1 + emodin group and 30% in the HSV-1 + ACV group, respectively. The expression of IL-6, TNF-α and IFN-β decreased by 30%-50% in the HSV-1 + emodin group and showed no significant change in the HSV-1 + ACV group, respectively. Conclusion: Emodin could inhibit the inflammatory response in the brain of mice with herpes virus encephalitis. The inhibition of TLR3 expression may play an important role in this process. [ABSTRACT FROM AUTHOR]