Effects of Polygonum hydropiper on the expressions of inflammatory cytokines and cytochrome P450 enzymes in mice with E.coli-induced diarrhea

In the present study,we aimed to investigate the effects of Polygonum hydropiper aqueous extract(PHE)on the expression levels of inflammatory cytokines and cytochrome P450(CYPs)in mice with E.coli-induced diarrhea.BALB/c mice were randomly divided into the control group,model group,enrofloxacin-treated group,and two PHE-treated groups with different doses.The diarrhea model was established by intraperitoneal injection of enteropathogenic E.coli(EPEC)in mice.The enrofloxacin-treated group was given enrofloxacin at 5 mg/kg by intragastric gavage(i.g.)for 11 d.PHE-treated groups were given PHE at 5 g/kg and 10 g/kg by i.g.for 11 d.The histopathological characteristics of the duodenum and liver were observed by HE staining.The levels of inflammatory cytokines and CYPs in the duodenum and liver of mice were determined by ELISA.The m RNA and protein expressions of CYPs were determined by q RT-PCR and Western blotting analysis,respectively.The results showed that PHE could significantly alleviate the injury of the duodenum and liver induced by EPEC infection,reduce the contents and m RNA expressions of inflammatory cytokines,and regulate the m RNA and protein expressions of the major subtypes of CYPs.These findings indicated that PHE had an apparent therapeutic effect on EPEC-induced diarrhea,and its mechanism might be related to inhibition of inflammatory cytokines and regulation of CYPs.

Sensing bacterial infections by NAIP receptors in NLRC4 inflammasome activation

The inflammasome is an emerging new pathway in innate immune defense against microbial infection or endogenous danger signals.The inflammasome stimulates activation of inflammatory caspases,mainly caspase-1.Caspase-1 activation is responsible for processing and secretion of IL-1βand IL-18 as well as for inducing macrophage pyroptotic death.Assembly of the large cytoplasmic inflammasome complex is thought to be mediated by members of NOD-like receptor(NLR)family.While functions of most of the NLR proteins remain to be defined,several NLR proteins including NLRC4 have been shown to assemble distinct inflammasome complexes.These inflammasome pathways,particularly the NLRC4 inflammasome,play a critical role in sensing and restricting diverse types of bacterial infections.Here we review recent advances in defining the exact bacterial ligands and the ligand-binding receptors involved in NLRC4 inflammasome activation.Implications of the discovery of the NAIP family of inflammasome receptors for bacterial flagellin and type III secretion apparatus on future inflammasome and bacterial infection studies are also discussed.