Effects of Sanhuang plaster on expression of MyD88, TRAF6, MIP-1β and IL-23 in rats infected by MRSA

Objective: To investigate the effects of Sanhuang plaster on expression of myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor-related factor 6 (TRAF6), macrophage inflammatory protein-lβ (MIP-1β) and its mediated cytokine interleukin-23 (IL-23) in soft tissues of rats infected by methicillin-resistant Staphylococcus aureus (MRSA). Methods: Ninety-six healthy rats were randomly divided into normal control group, model control group, Mupirocin group, high, medium and low dose groups of Sanhuang plaster, with 16 rats in each group. MRSA bacterial liquid was used to make skin and soft tissue infection models. The rats in the normal control group and the model control group were not given any treatment measures. The high, medium, and low dose groups of Sanhuang plaster were given to the affected area with Sanhuang plaster, and the Mupirocin group was given to the affected area for treatment for 10 days. The wound pathological changes were observed. The levels of MIP-1β and IL-23 in serum and infected tissues of rats in each group were measured by ELISA. The mRNA expressions of MyD88, TRAF6, MIP-lβ and IL-23 were measured by Quantitative Real-time PCR, and Western blot was used to measure MyD88 and TRAF6 protein expression. Results: Compared with the model control group, the general condition of the Sanhuang plaster groups was significantly improved, and the pathological damage was reduced. The MIP-1β and IL-23 levels in the serum and infected tissues of the high dose group of Sanhuang plaster, the mRNA expressions of MyD88, TRAF6, MIP-1β and IL-23and in large and medium dose groups of Sanhuang plaster, and the protein expressions of Myd88 and TRAF6 in high dose of Sanhuang plaster were significantly decreased (p<0.05 or p<0.01). Conclusion: Sanhuang plaster may play a role in promoting healing of infected wounds by down-regulating the expression levels of MyD88, TRAF6, and MIP-1β, and inhibiting the abnormal secretion of cytokine IL-23.