Acacetin protects against cerebral ischemia-reperfusion injury via the NLRP3 signaling pathway

Acacetin(5,7-dihydroxy-4′-methoxyflavone), a potential neuroprotective agent, has an inhibitory effect on lipopolysaccharide-induced neuroinflammatory reactions. However, whether acacetin has an effect on inflammatory corpuscle 3(NLRP3) after cerebral ischemia-reperfusion injury has not been fully determined. This study used an improved suture method to establish a cerebral ischemia-reperfusion injury model in C57BL/6 mice. After ischemia with middle cerebral artery occlusion for 1 hour, reperfusion with intraperitoneal injection of 25 mg/kg of acacetin(acacetin group) or an equal volume of saline(0.1 mL/10 g, middle cerebral artery occlusion group) was used to investigate the effect of acacetin on cerebral ischemia-reperfusion injury. Infarct volume and neurological function scores were determined by 2,3,5-triphenyltetrazolium chloride staining and the Zea-Longa scoring method. Compared with the middle cerebral artery occlusion group, neurological function scores and cerebral infarction volumes were significantly reduced in the acacetin group. To understand the effect of acacetin on microglia-mediated inflammatory response after cerebral ischemia-reperfusion injury, immunohistochemistry for the microglia marker calcium adapter protein ionized calcium-binding adaptor molecule 1(Iba1) was examined in the hippocampus of ischemic brain tissue. In addition, tumor necrosis factor-α, interleukin-1β, and interleukin-6 expression in ischemic brain tissue of mice was quantified by enzyme-linked immunosorbent assay. Expression of Iba1, tumor necrosis factor-α, interleukin-1β and interleukin-6 was significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Western blot assay results showed that expression of Toll-like receptor 4, nuclear factor kappa B, NLRP3, procaspase-1, caspase-1, pro-interleukin-1β, and interleukin-1β were significantly lower in the acacetin group compared with the middle cerebral artery occlusion group. Our findings indicate that acacetin has a protective effect on cerebral ischemia-reperfusion injury, and its mechanism of action is associated with inhibition of microglia-mediated inflammation and the NLRP3 signaling pathway.

Puerarin protects rat brain against ischemia/reperfusion injury by suppressing autophagy via the AMPK-mT OR-ULK1 signaling pathway

Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPKm TOR signaling pathway regulates the activation of the autophagy pathway through the coordinated phosphorylation of ULK1. In this study, we investigated the mechanisms underlying the neuroprotective effect of puerarin and its role in modulating autophagy via the AMPK-m TOR-ULK1 signaling pathway in the rat middle cerebral artery occlusion model of cerebral ischemia/reperfusion injury. Rats were intraperitoneally injected with puerarin, 50 or 100 mg/kg, daily for 7 days. Then, 30 minutes after the final administration, rats were subjected to transient middle cerebral artery occlusion for 90 minutes. Then, after 24 hours of reperfusion, the Longa score and infarct volume were evaluated in each group. Autophagosome formation was observed by transmission electron microscopy. LC3, Beclin-1 p62, AMPK, m TOR and ULK1 protein expression levels were examined by immunofluorescence and western blot assay. Puerarin substantially reduced the Longa score and infarct volume, and it lessened autophagosome formation in the hippocampal CA1 area following cerebral ischemia/reperfusion injury in a dose-dependent manner. Pretreatment with puerarin（50 or 100 mg/kg） reduced Beclin-1 expression and the LC3-II/LC3-I ratio, as well as p-AMPK and p S317-ULK1 levels. In comparison, it increased p62 expression. Furthermore, puerarin at 100 mg/kg dramatically increased the levels of p-m TOR and p S757-ULK1 in the hippocampus on the ischemic side. Our findings suggest that puerarin alleviates autophagy by activating the APMK-m TOR-ULK1 signaling pathway. Thus, puerarin might have therapeutic potential for treating cerebral ischemia/reperfusion injury.

To investigate the effect of Shenqi Tiaoshen Formula on CSE induced inflammatory response of MH-S cells based on TLR4/NF-kB/NLRP3 pathway

Objective:To study the effects of Shenqi Tiaoshen Formula(SQTS)on the inflammatory response of MH-S cells induced by cigarette smoking extract(CSE)and its mechanism based on TLR4/NF-kB/NLRP3 pathway.Methods:MH-S cells were used as subjects to evaluate cell viability by CCK-8 method.The levels of TNF-α,IL-1βand IL-6 in the supernatant were detected by ELISA.ROS were detected by DCFH-DA fluorescence probe.Western blotting was used to detect the expression of TLR4/NF-kB/NLRP3 pathway protein,and TAK-242,a TLR4 inhibitor,was used to verify the role of SQTS in the TLR4/NF-kB/NLRP3 pathway.Results:Compared with blank group,the cell survival rate of CSE group was decreased,and the contents of inflammatory cytokines TNF-α,IL-1βand IL-6 were increased(P<0.05),ROS fluorescence expression level was significantly increased(P<0.01),TLR4/NF-kB/NLRP3 pathway protein expression was significantly increased(P<0.05);Compared with CSE group,the survival rate of cells in SQTS groups was increased,and the expression levels of the above indexes were decreased(P<0.05),and TLR4/NF-kB/NLRP3 pathway protein decreased in TAK-242 groups(P<0.05).Conclusion:SQTS can reduce the inflammatory response of MH-S cells induced by CSE by inhibiting TLR4/NF-kB/NLRP3 pathway.

Mechanism of Sanshi decoction in the treatment of gouty arthritis by NLRP3 inflammasome

Objective:To observe the effect of Sanshi decoction on P2X7R/PKR pathway-mediated activation of macrophage NLRP3 inflammasome to elucidate the molecular mechanism of Sanshi decoction in the treatment of gouty arthritis.Methods:THP-1 macrophages were divided into control group,model group,low dose group,medium dose group,high dose group of Sanshi decoction and inhibitor group.The remaining groups were induced with monosodium urate crystals to establish a gouty arthritis cell model except the control group.Flow cytometry was used to detect macrophage ROS levels in each group,ELISA to detect MDA levels and SOD and GSH-PX activities in each group,and Western blot to detect P2X7R/PKR pathway and NLRP3 inflammasome-associated protein expression.We also used CCK-8 and flow cytometry to measure MH7A activity and apoptotic levels.Results:Compared with the control group,the ROS level,the content of MDA,the activities of SOD and GSH-PX were significantly increased,and the expression levels of NLRP3,full-length IL-1β,pro-IL-1β,full-length IL-18,pro-IL-18,full-length caspase-1,GSDMD-NT,P2X7R and p-PKR protein expression levels were significantly upregulated,and GSDMD-FL protein expression was significantly downregulated in the model group,and that the differences between them were statistically significant(P<0.05 and P<0.01).Compared with the model group,Sanshi decoction could reduce macrophage ROS levels,MDA content,SOD and GSHPX activities,and downregulate macrophage NLRP3,mature IL-1β,pro IL-1β,mature IL-18,pro IL-18,mature caspase-1,GSDMD-NT,P2X7R and p-PKR protein expression,and upregulate GSDMD-FL protein expression,with statistically significant differences(P<0.05 and P<0.01).In addition,MH7A activity was downregulated,and apoptosis level was upregulated in the model group in comparison with the control group,and differences were all significantly different(P<0.05).As compared to the model group,Sanshi decoction could significantly increase the activity of MH7A and inhibit the level of apoptosis,and that the differences between them were statistically significant(P<0.05 and P<0.01).Conclusion:Sanshi decoction can achieve the therapeutic effect of gouty arthritis by inhibiting P2X7R/PKR pathway activation,thus reducing the activation level of NLRP3.

Huoxin Pill Reduces Myocardial Ischemia Reperfusion Injury in Rats via TLR4/NFκB/NLRP3 Signaling Pathway

Objective:To explore the protective effect of Huoxin Pill(HXP)on acute myocardial ischemia-reperfusion(MIRI)injury in rats.Methods:Seventy-five adult SD rats were divided into the sham-operated group,model group,positive drug group(diltiazem hydrochloride,DH),high dose group(24 mg/kg,HXP-H)and low dose group(12 mg/kg,HXP-L)of Huoxin Pill(n=15 for every group)according to the complete randomization method.After 1 week of intragastric administration,the left anterior descending coronary artery of the rat's heart was ligated for 45 min and reperfused for 3 h.Serum was separated and the levels of creatine kinase(CK),creatine kinase isoenzyme(CK-MB)and lactate dehydrogenase(LDH),superoxide dismutase(SOD),and malondialdehyde(MDA),hypersensitive C-reactive protein(hs-CRP)and interleukin-1β(IL-1β)were measured.Myocardial ischemia rate,myocardial infarction rate and myocardial no-reflow rate were determined by staining with Evans blue and 2,3,5-triphenyltetrazolium chloride(TTC).Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP)and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine(BATMAN)databases were used to screen for possible active compounds of HXP and their potential therapeutic targets;the results of anti-inflammatory genes associated with MIRI were obtained from GeneC ards,Drugbank,Online Mendelian Inheritance in Man(OMIM),and Therapeutic Target Datebase(TTD)databases was performed;Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment were used to analyze the intersected targets;molecular docking was performed using AutoD ock Tools.Western blot was used to detect the protein expression of Toll-like receptor 4(TLR4)/nuclear factor kappa-B(NFκB)/NOD-like receptor protein 3(NLRP3).Results:Compared with the model group,all doses of HXP significantly reduced the levels of LDH,CK and CK-MB(P<0.05,P<0.01);HXP significantly increased serum activity of SOD(P<0.05,P<0.01);all doses of HXP significantly reduced the levels of hs-CRP and IL-1β(P<0.05,P<0.01)and the myocardial infarction rate and myocardial no-reflow rate(P<0.01).GO enrichment analysis mainly involved positive regulation of gene expression,extracellular space and identical protein binding,KEGG pathway enrichment mainly involved PI3K-Akt signaling pathway and lipid and atherosclerosis.Molecular docking results showed that kaempferol and luteolin had a better affinity with TLR4,NFκB and NLRP3 molecules.The protein expressions of TLR4,NFκB and NLRP3 were reduced in the HXP group(P<0.01).Conclusions:HXP has a significant protective effect on myocardial ischemia-reperfusion injury in rats,and its effect may be related to the inhibition of redox response and reduction of the inflammatory response by inhibiting the TLR4/NFκB/NLRP3 signaling pathway.

Hepatic protective effects of Shenling Baizhu powder, a herbal compound, against inflammatory damage via TLR4/NLRP3 signalling pathway in rats with nonalcoholic fatty liver disease

Objective: High-fat diet(HFD) and inflammation are two key contributors to nonalcoholic fatty liver disease(NAFLD). Shenling Baizhu powder(SLBZP), a classical herbal compound, has been successfully used to alleviate NAFLD. However, its specific mechanisms are not fully understood. In this study, we assessed the anti-NAFLD effect of SLBZP in vivo.Methods: Rats were fed an HFD with or without SLBZP or with probiotics. At the end of week 16, an echo magnetic resonance imaging(EchoMRI) body composition analyser was used to quantitatively analyse body composition;a micro-computed tomography(micro-CT) imaging system was used to evaluate whole body and liver fat;and the Moor full-field laser perfusion imager 2 was used to assess liver microcirculation, after which, all rats were sacrificed. Then, biochemical indicators in the blood and the ultrastructure of rat livers were evaluated. Protein expression related to the liver Toll-like receptor 4(TLR4)/Nod-like receptor family pyrin domain-containing 3(NLRP3) signalling pathway was assessed using Western blot analysis. Further, high-throughput screening of 29 related inflammatory factors in liver tissue was performed using a cytokine array.Results: SLBZP supplementation reduced body weight, serum free fatty acid, and insulin resistance index(P<0.05). It also ameliorated liver microcirculation and ultrastructural abnormalities. EchoMRI and micro-CT quantitative analyses showed that treatment with SLBZP reduced fat mass and visceral fat(P<0.05 and P<0.01, respectively). In addition, SLBZP decreased the expression of lipopolysaccharide(LPS)-activated TLR4/NLRP3 signalling pathway-related proteins and altered the expression levels of some inflammatory cytokines in liver tissues.Conclusion: SLBZP can inhibit NLRP3 inflammasome activation and interleukin-1 b release by suppressing LPS-induced TLR4 expression in rats with HFD-induced NAFLD. Thus, SLBZP may be beneficial for the prevention and treatment of inflammatory damage and associated diseases.

Anti-hyperglycemic effects of dihydromyricetin in streptozotocin-induced diabetic rats

Dihydromyricetin(DHM),as a bioactive flavanonol compound,is mainly found in“Tengcha”(Ampelopsis grossedentata)cultivated in south of China.This study aimed to investigate the anti-hyperglycemic and antidyslipidemic activities of DHM using type 2 diabetes mellitus(T2D)rats,which was induced by feeding with high fat and fructose diet for 42 days and intraperitoneal administration of streptozocin.Forty-eight freshlyweaned rats were randomly assigned into the negative control(Blank),low dose(100 mg/kg),medium dose(200 mg/kg),high dose(400 mg/kg),and positive(40 mg/kg,met)groups.Fasting blood glucose and body weight were measured at weekly interval.Oral glucose tolerance tests were performed on days 42.The results revealed that DHM possessed significant antihyperglycaemic and antihyperinsulinemic effects.Moreover,after the DHM treatment,p-Akt and p-AMPK expression was upregulated,and glycogen synthase kinase-3β(GSK-3β)expression was downregulated,indicating that the potential anti-diabetic mechanism of DHM might be due to the regulation of the AMPK/Akt/GSK-3βsignaling pathway.

Novel nervous and multi-system regenerative therapeutic strategies for diabetes mellitus with mTOR

Throughout the globe,diabetes mellitus（DM） is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder.DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy.The mechanistic target of rapamycin（m TOR） is a promising agent for the development of novel regenerative strategies for the treatment of DM.m TOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis,insulin resistance,insulin secretion,stem cell proliferation and differentiation,pancreatic β-cell function,and programmed cell death with apoptosis and autophagy.m TOR is central element for the protein complexes m TOR Complex 1（m TORC1） and m TOR Complex 2（m TORC2） and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase（PI 3-K）,protein kinase B（Akt）,AMP activated protein kinase（AMPK）,silent mating type information regulation 2 homolog 1（Saccharomyces cerevisiae）（SIRT1）,Wnt1 inducible signaling pathway protein 1（WISP1）,and growth factors.As a result,m TOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease.Future studies directed to elucidate the delicate balance m TOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.

Study on the mechanism and active components of Radix et Rhizoma Rhei in the treatment of Alzheimer's disease based on molecular docking

Objective:To explore the mechanism and active components of Radix et Rhizoma Rhei in the treatment of Alzheimer's disease(AD)based on molecular docking.Methods:22 major components of Radix et Rhizoma Rhei were screened from TCMSP and related literatures,which docked with the key targets of NLRP3/Caspase-1/GSDMD signaling pathway.NLRP3,Caspase-1,GSDMD inhibitors MCC950,ML132 and LDC7559 were used as positive control to analyze the docking results.Results:The docking results showed that the main components of Radix et Rhizoma Rhei had different degrees of binding with NLRP3,Caspase-1 and GSDMD targets,and the potential active components were mutanochrome and physciondiglucoside.Conclusion:Molecular docking predicts that the main components of Radix et Rhizoma Rhei may act on NLRP3/Caspase-1/GSDMD signaling pathway,and the active components may be mutanochrome and physciondiglucoside,which provides theoretical basis for revealing the anti-inflammatory mechanism and active components of Radix et Rhizoma Rhei in the treatment of AD.

Whey protein peptide PEW attenuates hyperuricemia and associated renal inflammation in potassium oxonate and hypoxanthine-induced rat

Pro-Glu-Trp(PEW),a whey protein-derived peptide,has been previously shown in vitro to have antihyperuricemic potential.The current study further evaluated the roles and the underlying mechanism of PEW in the management of hyperuricemia(HUA)in rat induced by potassium oxonate(PO)and hypoxanthine.Results revealed that PEW significantly reduced the levels of uric acid(UA),creatinine(Cr),and blood urea nitrogen(BUN)in serum,and effectively suppressed the activities of xanthine oxidase(XOD)associated with UA synthesis and modulated the expression of organic ion transporters related to UA excretion.Moreover,PEW alleviated UAinduced renal inflammation by regulating oxidative stress,suppressing the level of pro-inflammatory cytokines,and inhibiting the activation of NOD-like receptor family pyrin domain-containing 3(NLRP3)inflammasome and Toll-like receptor 4/myeloid differentiation factor 88/NF-kappaB(TLR4/MyD88/NF-κB)signaling pathway.Taken together,these relults indicated that PEW improved HUA and renal inflammation by inhibiting UA synthesis,promoting renal UA excretion and suppressing NLRP3 inflammasome and TLR4/MyD88/NF-κB signaling pathways.