Anti-inflammatory Effect Of Resveratrol And It Mitigates Lipopolysaccharide-mediated Acute Inflammation In Rats By Inhibiting The TLR4/NF-?Bp65/MAPKs Signaling Cascade

Resveratrol(3,5,40-trihydroxystilbene,RSV)is a polyphenolic compound possess varieties of pharmacological activities,while in this study,we only focus on it's anti-inflammatory activity.Although there were many reports about anti-inflammatory activity and anti-inflammatory mechanism of RSV,these mechanism studies nearly based on a certain protein or a gene,a signaling pathway,even on the joint action of two of them,hardly through signal cascade.Futhermore,Lipopolysaccharides(LPS)is widely used in manufacturing of the acute inflammation model.Previous researches have confirmed that LPS induces inflammatory response mainly contribute to activating Toll-like receptor 4(TLR4)signaling pathway,which leading to the production of inflammatory cytokines,such as IL-1?,IL-6 and IL-8 and so on.Based on the theories above,this study select RSV as the research object and use intraperitoneal injection with LPS in rats to make acute inflammation model.The aim of this study is preliminaryly to explore the influence of RSV on hematology indexes,tissue organs and inflammatory cytokines to comfirm the RSV-treated main target organs;on the base of the main target organs,we adopt molecular biology methods including RT-PCR and Western Blot to clarify the anti-inflammatory mechanism of RSV through TLR4/NF-?Bp65/MAPKs signaling cascade.The followings are the main results of this study:1 Anti-inflammatory activity of resveratrol1.1 The influence of RSV on rat's organs:The acute inflammation model of this study was manufactured by intraperitoneal injection with LPS.Evaluate the anti-inflammatory activity of RSV through determination organ wet/dry weight ratios and pathology research.The results showed that:? LPS could significantly raise the organ wet/dry weight ratios of liver and lung,but no obvious effect on rat's heart,spleen and kidney;RSV could significantly reduce organ wet/dry weight ratio of rat's liver and lung;? LPS could cause inflammatory lesions of liver and lung,but no obvious effect on rat's heart,spleen and kidney;RSV possesses a better anti-inflammatory effect,which could effectively alleviate the lesions of liver and lung.The results above show that:RSV could effectively alleviate the inflammatory symptom of organizations which induced by LPS,suggesting it plays a certain role to protect liver and lung.1.2 The influence of RSV on hematological indexes:In order to explore the influence of RSV on LPS-induced hematological changes,the blood of rats was collected from eyeballs and the results showed that:? RSV could restore the production of WBC,RBC,PLT,LYM,GRA,MON,HGB and HCT to normal level;? RSV could prompt ALP,ALT and AST to normal level,while no significant effect on the expression of BUN,CRE and CHO.These results showed that:RSV possesses a better anti-inflammatory effect on LPS-induced inflammation,which could maintain the stability of blood system and restore the abnormal situation of liver's indexes,RSV probably plays a protective effect to liver and this result was consistent with the results of rat's organ wet/dry weight ratios and histopathological detections.1.3 The influence of RSV on inflammatory cytokines in rat's serum:This test adopts ELISA method to detect the expressions of inflammatory cytokines and mediators in rat's serum.The results showed that:RSV could significantly inhibit the production of proinflammatory mediators and cytokines,including IL-1,IL-1?,IL-6,IL-8,NO,iNOS,PGE2 and COX-2,but elevate the production of IL-10,suggesting that the anti-inflammatory effect of RSV may realized by down-regulating proinflammuatory factors while up-regulating the anti-inflammatory factor.2 The influence of RSV on TLR4/NF-?Bp65/MAPKs signal pathway related gene's mRNA expression:This study select the main target organs(liver and lung)as mechanism research objects,and use RT-PCR reaction system for detecting the mRNA expressions of TLR4/NF-?Bp65/MAPKs pathway related genes.The results showed that:RSV could significantly down-regulated the mRNA level of MyD88,TRAF6,I?B?,P38,JNK,ERK1,ERK2 and ERK5 both in liver and lung.RSV could inhibit the activation of TLR4 signaling pathway on transcription level,and the inhibitory effect of TLR4 make the inhibiton of NF-?Bp65 and MAPKs signaling pathways.Therefore,RSV may regulate the expression of proinflammatory cytokines and anti-inflammatory factor by suppressing the TLR4/NF-?Bp65/MAPKs signal cascade through inhibiting the transcription of related genes.3 The influence of RSV on TLR4/NF-?Bp65/MAPKs signal pathway related protein's expression:This test adopts Western Blot method to measure the expression of TLR4/NF-?Bp65/MAPKs pathway related protein and phosphorylatory protein in liver's and lung's cytoplasm and nucleus.The results showed that:RSV could restrain the transfer of TLR4,IKBa,NF-?Bp65,P38,JNK,ERK1/2 and ERK5 from liver's and lung's cytoplasm into nucleus,which making the cytoplasmic proteins in a certain level,but relative reducing the nucleus proteins.It suggesting that RSV could inhibit the activation of TLR4 signaling pathway on translation level,thereby,inhibit the NF-xBp65 and MAPKs signaling cascades and finally regulate the expressions of proinflammatory cytokines and anti-inflammatory factor.Above all,RSV possesses a better anti-inflammatory effect on LPS-induced inflammation,which could maintain the stability of blood system and alleviate the lesions of liver and lung.The anti-inflammatory mechanism of RSV maybe related to suppressing the activation of TLR4 signaling pathway at transcription and translation levels,which further suppressing the activations of NF-KBp65 and MAPKs(P38,JNK,ERK1/2,ERK5)signaling cascades,and eventually regulating the production of inflammatory cytokines and mediators in serum.