Research of emodin regulating TLR4/NF-κB signaling pathway on healing of infected wound in rats
Objective To investigate the effects of emodin on the healing of infected wound and the regulation of Toll-likereceptor 4(TLR4)/nuclear factor kappa-B(NF-κB)signaling pathway in rats.Methods The model of infectious wounds rats were constructed by the full-thickness skin defect method.The successful model rats were randomly divided into model group,control group and experimental-L,-M,-H groups with 12 rats per group;another 12 normal rats were taken as the normal group.Experimental-L,-M,-H groups was applied with emodin 150,300 and 600 μg·d-1 and 200 mg·kg-1 emodin by gavage,respectively.Control group was applied with mopirolacin cream 0.1 g·d-1 on rat wounds,once a day.Normal and model groups were treated with 0.9%NaCl.Six groups were treated for 21 days.The wound healing rates and dynamic blood flow were measured.The levels of tumor necrosis factor(TNF)-α and interleukin(IL)-1β in serum and the hydroxyproline(HYP)and catalase(CAT)in wound tissue were measured by enzyme linked immunosorbent assay.The protein levels of TLR4 and NF-κB in wound were determined by Western blot.Results The wound healing rates of experimental-M,-H groups,control group and model group were(50.70±1.26)%,(75.51±0.50)%,(69.44±1.65)%and(28.58±5.09)%,respectively.The dynamic blood flow values of experimental-M,-H groups,control group,model group and blank group were(123.71±3.71),(155.61±2.47),(146.29±2.04),(79.47±4.76)and(158.00±1.93)mL·min-1;the levels of TNF-α were(81.05±2.32),(56.69±1.59),(69.53±2.39),(139.46±2.46)and(46.49±5.71)ng·L-1;the levels of IL-1β were(59.87±0.83),(42.66±1.30),(48.37±3.34),(88.79±1.84)and(33.93±2.19)ng·L-1;the levels of HYP were(24.79±0.82),(31.12±1.16),(25.83±1.12),(16.88±2.20)and(32.95±1.18)pg·mg-1;the levels of CAT were(24.99±1.47),(34.52±1.26),(31.00±1.15),(13.70±2.09)and(34.23±0.70)U·mg-1;the relative expression levels of TLR4 protein were 0.74±0.05,0.53±0.05,0.55±0.04,1.09±0.07 and 0.23±0.05;the relative expression levels of NF-κB protein were 0.69±0.06,0.44±0.04,0.52±0.03,1.10±0.04 and 0.22±0.10,respectively.Compared with the model group,the above indexes in the experimental-M,-H groups were statistically significant(all P<0.05).Conclusion Emodin can improve the infectious wound healing and dynamic blood flow in rats,and inhibit the inflammatory levels and oxidative stress response in wound tissue,and the mechanism may be related to the regulation of TLR4/NF-κB pathway.