Triptolide improves myocardial fibrosis in rats through inhibition of nuclear factor kappa B and NLR family pyrin domain containing 3 inflammasome pathway

Myocardial fibrosis (MF) is the result of persistent and repeated aggravation of myocardial ischemia and hypoxia, leading to the gradual development of heart failure of chronic ischemic heart disease. Triptolide (TPL) is identified to be involved in the treatment for MF. This study aims to explore the mechanism of TPL in the treatment of MF. The MF rat model was established, subcutaneously injected with isoproterenol and treated by subcutaneous injection of TPL. The cardiac function of each group was evaluated, including LVEF, LVFS, LVES, and LVED. The expressions of ANP, BNP, inflammatory related factors (IL-1β, IL-18, TNF-α, MCP-1, VCAM-1), NLRP3 inflammasome factors (NLRP3, ASC) and fibrosis related factors (TGF-β1, COL1, and COL3) in rats were dete cted. H&E staining and Masson staining were used to observe myocardial cell inflammation and fibrosis of rats. Western blot was used to detect the p-P65 and t-P65 levels in nucleoprotein of rat myocardial tissues. LVED and LVES of MF group were significantly upregulated, LVEF and LVFS were significantly downregulated, while TPL treatment reversed these trends; TPL treatment downregulated the tissue injury and improved the pathological damage of MF rats. TPL treatment downregulated the levels of inflammatory factors and fibrosis factors, and inhibited the activation of NLRP3 inflammasome. Activation of NLRP3 inflammasome or NF-κB pathway reversed the effect of TPL on MF. Collectively, TPL inhibited the activation of NLRP3 inflammasome by inhibiting NF-κB pathway, and improved MF in MF rats.     

Tanshinone IIA reduces pyroptosis in rats with coronary microembolization by inhibiting the TLR4/MyD88/NF-κB/NLRP3 pathway

Pyroptosis is an inflammatory form of programmed cell death that is linked with invading intracellular pathogens. Cardiac pyroptosis has a significant role in coronary microembolization (CME), thus causing myocardial injury. Tanshinone IIA (Tan IIA) has powerful cardioprotective effects. Hence, this study aimed to identify the effect of Tan IIA on CME and its underlying mechanism. Forty Sprague–Dawley (SD) rats were randomly grouped into sham, CME, CME + low-dose Tan IIA, and CME + high-dose Tan IIA groups. Except for the sham group, polyethylene microspheres (42 µm) were injected to establish the CME model. The Tan-L and Tan-H groups received intraperitoneal Tan IIA for 7 days before CME. After CME, cardiac function, myocardial histopathology, and serum myocardial injury markers were assessed. The expression of pyroptosis-associated molecules and TLR4/MyD88/NF-κB/NLRP3 cascade was evaluated by qRT-PCR, Western blotting, ELISA, and IHC. Relative to the sham group, CME group''s cardiac functions were significantly reduced, with a high level of serum myocardial injury markers, and microinfarct area. Also, the levels of caspase-1 p20, GSDMD-N, IL-18, IL-1β, TLR4, MyD88, p-NF-κB p65, NLRP3, and ASC expression were increased. Relative to the CME group, the Tan-H and Tan-L groups had considerably improved cardiac functions, with a considerably low level of serum myocardial injury markers and microinfarct area. Tan IIA can reduce the levels of pyroptosis-associated mRNA and protein, which may be caused by inhibiting TLR4/MyD88/NF-κB/NLRP3 cascade. In conclusion, Tanshinone IIA can suppress cardiomyocyte pyroptosis probably through modulating the TLR4/MyD88/NF-κB/NLRP3 cascade, lowering cardiac dysfunction, and myocardial damage.     

Inhibitory effects of rosiglitazone on paraquat-induced acute lung injury in rats

Aim:

To investigate the effects of the PPAR-γ agonist rosiglitazone on acute lung injury induced by the herbicide paraquat (PQ) and the underlying mechanisms of action.

Methods:

Male Sprague-Dawley rats were injected with PQ (20 mg/kg, ip). Rosiglitazone (3 or 10 mg/kg, ip) was administered 1 h before PQ exposure. Peripheral blood was collected at 4, 8, 24 and 72 h after PQ exposure for measuring the levels of MDA, TNF-α and IL-1β, and the SOD activity. Lung tissues were collected at 72 h after PQ exposure to determine the wet-to-dry (W/D) ratios and lung injury scores, as well as the protein levels of NF-κBp65, PPAR-γ, Nrf2, IκBα and pIκBα.

Results:

At 72 h after PQ exposure, the untreated rats showed a 100% cumulative mortality, whereas no death was observed in rosiglitazone-pretreated rats. Moreover, rosiglitazone pretreatment dose-dependently attenuated PQ-induced lung edema and lung histopathological changes. The pretreatment significantly reduced the levels of TNF-α, IL-1β and MDA, increased SOD activity in the peripheral blood of PQ-treated rats. The pretreatment also efficiently activated PPAR-γ, induced Nrf2 expression and inhibited NF-κB activation in the lung tissues of PQ-treated rats. Furthermore, the pretreatment dose-dependently inhibited IκB-α degradation and phosphorylation, thus inhibiting NF-κB activation.

Conclusion:

Pretreatment with rosiglitazone protects rats against PQ-induced acute lung injury by activating PPAR-γ, inducing Nrf2 expression and inhibiting NF-κB activation.     

Resveratrol pretreatment alleviates NLRP3 inflammasome-mediated cardiomyocyte pyroptosis by targeting TLR4/MyD88/NF-κB signaling cascade in coronary microembolization-induced myocardial damage

Percutaneous coronary intervention and acute coronary syndrome are both closely tied to the frequently occurring complication of coronary microembolization (CME). Resveratrol (RES) has been shown to have a substantial cardioprotective influence in a variety of cardiac diseases, though its function and potential mechanistic involvement in CME are still unclear. The forty Sprague–Dawley rats were divided into four groups randomly: CME, CME + RES (25 mg/kg), CME + RES (50 mg/kg), and sham (10 rats per group). The CME model was developed. Echocardiography, levels of myocardial injury markers in the serum, and histopathology of the myocardium were used to assess the function of the cardiac muscle. For the detection of the signaling of TLR4/MyD88/NF-κB along with the expression of pyroptosis-related molecules, ELISA, qRT-PCR, immunofluorescence, and Western blotting were used, among other techniques. The findings revealed that myocardial injury and pyroptosis occurred in the myocardium following CME, with a decreased function of cardiac, increased levels of serum myocardial injury markers, increased area of micro-infarct, as well as a rise in the expression levels of pyroptosis-related molecules. In addition to this, pretreatment with resveratrol reduced the severity of myocardial injury after CME by improving cardiac dysfunction, decreasing serum myocardial injury markers, decreasing microinfarct area, and decreasing cardiomyocyte pyroptosis, primarily by blocking the signaling of TLR4/MyD88/NF-κB and also reducing the NLRP3 inflammasome activation. Resveratrol may be able to alleviate CME-induced myocardial pyroptosis and cardiac dysfunction by impeding the activation of NLRP3 inflammasome and the signaling pathway of TLR4/MyD88/NF-κB.     

Protective effects and mechanism of coenzyme Q10 and vitamin C on doxorubicin-induced gastric mucosal injury and effects of intestinal flora

Doxorubicin (Dox) is widely used to the treatment of cancer, however, it could cause damage to gastric mucosa. To investigate the protective effects and related mechanisms of coenzyme Q10 (CoQ10) and vitamin C (VC) on Dox-induced gastric mucosal injury, we presented the survey of the 4 groups of the rats with different conditions. The results showed Dox treatment significantly induced GES-1 apoptosis, but preconditioning in GES-1 cells with VC or CoQ10 significantly inhibited the Dox-induced decrease and other harm effects, including the expression and of IκKβ, IκBα, NF-κB/p65 and tumor necrosis factor (TNF-α) in GES-1 cells. Moreover, high-throughput sequencing results showed Dox treatment increased the number of harmful gut microbes, and CoQ10 and VC treatment inhibited this effect. CoQ10 and VC treatment inhibits Dox-induced gastric mucosal injury by inhibiting the activation of the IkKB/IκBα/NF-κB/p65/TNF-α pathway, promoting anti-inflammatory effects of gastric tissue and regulating the composition of the intestinal flora.     

Gastroprotective effect of cirsilineol against hydrochloric acid/ethanol-induced gastric ulcer in rats

This study was designed to evaluate the gastroprotective activity of cirsilineol in hydrochloric acid (HCl)/ethanol-induced gastric ulcer model. Cirsilineol was administered at the doses of 20 and 40 mg/kg in HCl/ethanol-induced rats. The gastroprotective ability was verified by determining the ulcer score, total acidity, hemoglobin, inflammatory cytokines, lipid peroxides, and enzymatic antioxidants superoxide dismutase (SOD) and catalase (CAT) in gastric tissue and serum biochemical analysis. The results showed a favorable increase in the hemoglobin level, antioxidant enzymes (SOD and CAT), restored electrochemical balance (carbon dioxide & anion gap) while a noticeable decrease in ulcer index, total acidity, lipid peroxides, inflammatory cytokines (interleukin-1 beta [IL-1β], IL-6, and tumor necrosis factor alpha) in rats treated with the cirsilineol. The serum biochemical analysis on liver markers (alkaline phosphatases, alanine aminotransferase, and aspartate aminotransferase), kidney markers (urea, creatinine, albumin, globulin, total protein), and lipid profile (triglyceride, high-density lipoprotein, total cholesterol) were attenuated by cirsilineol treatment in rats. Histopathology showed enhanced gastric protection and preserved the integrity of gastric mucosa upon cirsilineol administration. These results ultimately suggest that cirsilineol has gastroprotective effects that prevent the development of gastric ulcer.     

Staphylococcal Enterotoxin A Induces Intestinal Barrier Dysfunction and Activates NLRP3 Inflammasome via NF-κB/MAPK Signaling Pathways in Mice

Staphylococcal enterotoxin A (SEA), the toxin protein secreted by Staphylococcus aureus, can cause staphylococcal food poisoning outbreaks and seriously threaten global public health. However, little is known about the pathogenesis of SEA in staphylococcal foodborne diseases. In this study, the effect of SEA on intestinal barrier injury and NLRP3 inflammasome activation was investigated by exposing BALB/c mice to SEA with increasing doses and a potential toxic mechanism was elucidated. Our findings suggested that SEA exposure provoked villi injury and suppressed the expression of ZO-1 and occludin proteins, thereby inducing intestinal barrier dysfunction and small intestinal injury in mice. Concurrently, SEA significantly up-regulated the expression of NLRP3 inflammasome-associated proteins and triggered the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathways in jejunum tissues. Notably, selective inhibitors of MAPKs and NF-κB p65 ameliorated the activation of NLRP3 inflammasome stimulated by SEA, which further indicated that SEA could activate NLRP3 inflammasome through NF-κB/MAPK pathways. In summary, SEA was first confirmed to induce intestinal barrier dysfunction and activate NLRP3 inflammasome via NF-κB/MAPK signaling pathways. These findings will contribute to a more comprehensive understanding of the pathogenesis of SEA and related drug-screening for the treatment and prevention of bacteriotoxin-caused foodborne diseases via targeting specific pathways.     

Salidroside protects against ventilation-induced lung injury by inhibiting the expression of matrix metalloproteinase-9

ContextSalidroside, a compound extracted from Rhodiola rosea L. (Crassulaceae), possesses many beneficial pathological effects.ObjectiveTo explore the effect of salidroside on ventilator-induced lung endothelial dysfunction in vivo and in vitro.Materials and methodsIn vivo, male ICR mice were divided into sham, ventilation, salidroside, and ventilation plus salidroside groups. The mice were ventilated for 4 h, salidroside (50 mg/kg) was administrated intraperitoneally before ventilation, dexamethasone (Dex) (5 mg/kg) was used as a positive control. In vitro, mouse lung vascular endothelial cells (MLVECs) were treated with salidroside, MMP-9 siRNA, and BAY11-7082 (10 μM), and then exposed to cyclic stretch for 4 h. Afterward, lung tissues and MLVECs were collected for further analysis.ResultsSalidroside pre-treatment significantly reversed the expression of vascular endothelial cadherin (VE-cadherin) and zonula occluden-1 (ZO-1) proteins in cyclic stretch-treated MLVECs (0.46 ± 0.09 vs. 0.80 ± 0.14, 0.49 ± 0.05 vs. 0.88 ± 0.08) and ventilated lung tissues (0.56 ± 0.06 vs. 0.83 ± 0.46, 0.49 ± 0.08 vs. 0.80 ± 0.12). The results further indicated that salidroside inhibited the expression of matrix metalloproteinase-9 (MMP-9), whereas knockdown of its expression restored the expression levels of VE-cadherin (0.37 ± 0.08 vs. 0.85 ± 0.74) and ZO-1 (0.48 ± 0.08 vs. 0.81 ± 0.11) in stretched MLVECs. Meanwhile, salidroside inhibited the NF-κB signalling pathway and alleviated lung injury.ConclusionsSalidroside protected against stretch-induced endothelial barrier function, improving lung injury after ventilation. Thus, salidroside may be a promising therapeutic agent for patients with MV-induced lung injury.     

Tanshinone IIA attenuates AOM/DSS-induced colorectal tumorigenesis in mice via inhibition of intestinal inflammation

Context Tanshinone IIA is a natural extract derived from a Chinese medicinal herb with multiple bioactivities; however, whether and how tanshinone IIA protects against colorectal cancer (CRC) are uncertain.Objective We investigated the potential beneficial effects of tanshinone IIA in a colitis-associated colorectal tumorigenesis mouse model and its underlying mechanisms.Materials and methods Male C57BL/6 mice were treated with azoxymethane (AOM) 10 mg/kg body weight and dextran sulphate sodium (2.5% DSS) to induce a colitis-associated cancer model. Tanshinone IIA (200 mg/kg body weight) was given to the mice intraperitoneally. After 12 weeks, all mice were sacrificed to measure tumour formation, intestinal permeability, neutrophil infiltration, and colonic inflammation. In addition, whether tanshinone IIA has inhibitory effects on neutrophil activation was determined through in vitro investigations.Results We observed that tanshinone IIA significantly decreased tumour formation in AOM/DSS-treated mice compared to AOM/DSS-treated alone mice (0.266 ± 0.057 vs. 0.78 ± 0.153, p = 0.013). Tanshinone IIA also decreased intestinal permeability compared to that in AOM/DSS-treated alone mice (3.12 ± 0.369 vs. 5.06 ± 0.597, p = 0.034) and consequently reduced neutrophil infiltration of the colonic mucosa (53.25 ± 8.85 vs. 107.6 ± 13.09, p = 0.014) as well as intestinal inflammation in mice. Mechanistically, tanshinone IIA downregulated the NF-κB signalling pathway in the colonic tumours of AOM/DSS-treated mice. In vitro assays further validated that tanshinone IIA suppressed LPS-induced neutrophil activation.Conclusion These data suggest that tanshinone IIA alleviates colorectal tumorigenesis through inhibition of intestinal inflammation. Tanshinone IIA may have a therapeutic potential for CRC in clinical practice.     

Cancer Cell Growth Inhibitory Effect of Bee Venom via Increase of Death Receptor 3 Expression and Inactivation of NF-kappa B in NSCLC Cells

Our previous findings have demonstrated that bee venom (BV) has anti-cancer activity in several cancer cells. However, the effects of BV on lung cancer cell growth have not been reported. Cell viability was determined with trypan blue uptake, soft agar formation as well as DAPI and TUNEL assay. Cell death related protein expression was determined with Western blotting. An EMSA was used for nuclear factor kappaB (NF-κB) activity assay. BV (1–5 μg/mL) inhibited growth of lung cancer cells by induction of apoptosis in a dose dependent manner in lung cancer cell lines A549 and NCI-H460. Consistent with apoptotic cell death, expression of DR3 and DR6 was significantly increased. However, deletion of DRs by small interfering RNA significantly reversed BV induced cell growth inhibitory effects. Expression of pro-apoptotic proteins (caspase-3 and Bax) was concomitantly increased, but the NF-κB activity and expression of Bcl-2 were inhibited. A combination treatment of tumor necrosis factor (TNF)-like weak inducer of apoptosis, TNF-related apoptosis-inducing ligand, docetaxel and cisplatin, with BV synergistically inhibited both A549 and NCI-H460 lung cancer cell growth with further down regulation of NF-κB activity. These results show that BV induces apoptotic cell death in lung cancer cells through the enhancement of DR3 expression and inhibition of NF-κB pathway.     

In vivo and in vitro studies of Danzhi Jiangtang capsules against diabetic cardiomyopathy via TLR4/MyD88/NF-κB signaling pathway

ObjectivesDanzhi Jiangtang capsule (DJC) is widely used for preventing and treating diabetic cardiomyopathy (DCM). However, the underlying mechanisms of the anti-inflammatory and antiapoptotic activities are unclear.MethodsIn the in vivo diabetic cardiomyopathy rat model, cardiac function was measured through echocardiography, histological changes in the myocardium were visualized using HE staining, and cardiomyocyte apoptosis was detected using TUNEL. The serum levels of anti-inflammatory cytokines were detected using ELISA. Finally, TLR4, MyD88, and NF-κB mRNA expressions were analyzed using RT-qPCR. In the in vitro experiments, the apoptosis rate of the H9c2 cells was detected using FCM; moreover, TLR4, MyD88 and NF-κB mRNA expressions were measured using RT-qPCR and related protein levels were investigated using Western blotting.ResultsIn vivo, DJC effectively improved cardiac function, alleviated the pathological changes, and reduced the apoptosis rate. Moreover, DJC reduced TNF-α, IL-1β, and IL-6 activities, with significant inhibition of the TLR4, MyD88 and NF-κB p65 mRNA expression. Moreover, in vitro, DJC effectively inhibited high-glucose-induced H9c2 apoptosis-an effect similar to that for TAK242. Finally, both the DJC and TAK242 considerably reduced TLR4, MyD88, NF-κB, Bax, and caspase-3 protein expression but increased that of BCL-2.ConclusionsDJC prevented the overactivation of the TLR4/MyD88/NF-κB signaling pathway and regulate cardiomyocyte apoptosis against DCM.     

Tobacco smoke affects expression of peroxisome proliferator-activated receptor-γ in monocyte/macrophages of patients with coronary heart disease

Background and purpose:

Tobacco smoke represents a relevant risk factor for coronary heart disease (CHD). Although peroxisome proliferator-activated receptor (PPAR)γ activation reduces inflammation and atherosclerosis, expression of PPARγ in cells and its modulation by smoking are poorly investigated. We previously reported that monocyte/macrophages from healthy smokers exhibited an enhanced constitutive expression of PPARγ. Here, we evaluated PPARγ expression and basal cytokine release in monocytes and monocyte-derived macrophages (MDMs) from 85 CHD patients, classified by their smoking habit (smokers, non-smokers and ex-smokers), and assessed the role of PPARγ ligands in this context.

Experimental approach:

PPARγ protein was detected by Western blot and semi-quantified by PPARγ/β-actin ratio; cytokine release was measured by elisa and nuclear factor-kappaB (NF-κB) translocation by electrophoretic mobility shift assays.

Key results:

As compared to the other groups, MDMs from smoker CHD patients exhibited a reduced PPARγ/β-actin ratio and an increased spontaneous release of tumour necrosis factor-α (TNF-α) and interleukin-6, but with no major variations in monocytes. In cells from selected CHD patients, rosiglitazone inhibited TNF-α release and NF-κB translocation induced by phorbol-12-myristate 13-acetate. The selective PPARγ antagonist GW9662 reversed these effects, with some variations related to smoking habit.

Conclusions and implications:

In CHD patients, exposure to tobacco smoke profoundly affected PPARγ expression, and this was related to levels of secretion of pro-inflammatory cytokines. MDMs from CHD smokers showed the lowest PPARγ expression and released more inflammatory cytokines. Moreover, rosiglitazone''s ability to inhibit cytokine release and its reversal by GW9662 clearly indicated PPARγ involvement in these changes in CHD patients.     

Tachykinin receptor modulation of cyclooxygenase-2 expression in human polymorphonuclear leucocytes

Background and purpose:

We investigated the ability of natural and synthetic selective NK receptors agonists and antagonists to modulate cyclooxygenase-2 (COX-2) expression in human polymorphonuclear leucocytes (PMNs).

Experimental approach:

The presence of all three tachykinin in PMNs was assessed by Western blot and PCR techniques. Natural and synthetic ligands selective for the tachykinin receptors were used to modulate COX-2 protein (measured with Western blotting) and activity [as prostaglandin E₂ (PGE₂) output]. Effects of substance P (SP) on phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) activation were studied to analyse the signalling pathway involved in COX-2 up-regulation mediated by SP.

Key results:

Stimulation of NK receptors with the natural ligands SP, neurokinin A (NKA) and neurokinin B, in the pmol·L⁻¹-µmol·L⁻¹ concentration range, modulated COX-2 expression and PGE₂ release in a concentration- and time-dependent manner. Experiments with synthetic selective agonists [Sar⁹, Met(O₂)¹¹]SP, [β-Ala⁸] NKA(4-10), senktide or selective antagonists L703,606, SR48,968 or SR142801, confirmed that COX-2 up-regulation was mediated by NK receptors. We found that mainly p38, p42 and p46 MAPKs were phosphorylated by SP and SB202190, PD98059 and SP600125, which are selective inhibitors of these kinases, blocked SP-induced COX-2 expression. SP also induced nuclear translocation of NF-κB concentration-dependently, with a maximum effect at 1 nmol·L⁻¹.

Conclusions and implications:

Human PMNs possess functional NK₁, NK₂ and NK₃ receptors, which mediate the induction of COX-2 expression and NF-κB activation by SP.     

Paeoniflorin ameliorates neuropathic pain-induced depression-like behaviors in mice by inhibiting hippocampal neuroinflammation activated via TLR4/NF-κB pathway

Neuropathic pain (NP) that contributes to the comorbidity between pain and depression is a clinical dilemma. Neuroinflammatory responses are known to have potentially important roles in the initiation of NP and depressive mood. In this study, we aimed to investigate the effects of paeoniflorin (PF) on NP-induced depression-like behaviors by targeting the hippocampal neuroinflammation through the toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway. We used a murine model of NP caused by unilateral sciatic nerve cuffing (Cuff). PF was injected intraperitoneally once a day for a total of 14 days. Pain and depression-like behavior changes were evaluated via behavioral tests. Pathological changes in the hippocampus of mice were observed by H&E staining. The levels of proinflammatory cytokines in the hippocampus were detected using ELISA. Activated microglia were measured by immunohistochemical staining. The TLR4/NF-κB signaling pathway-associated protein expression in the hippocampus was detected by western blotting. We found that the PF could significantly alleviate Cuff-induced hyperalgesia and depressive behaviors, lessen the pathological damage to the hippocampal cell, reduce proinflammatory cytokines levels, and inhibit microglial over-activation. Furthermore, PF downregulated the expression levels of TLR4/NF-κB signaling pathway-related proteins in the hippocampus. These results indicate that PF is an effective drug for improving the comorbidity between NP and depression.     

C‐phycocyanin protects against ethanol‐induced gastric ulcers in rats: Role of HMGB1/NLRP3/NF‐κB pathway

Gastric ulcer is a widespread inflammatory disease with high socio‐economic burden. C‐phycocyanin is one of the active constituents of Spirulina microalgae, and although it is well known for its antioxidant and anti‐inflammatory properties, its protective effects against gastric ulcer have not yet been identified. High‐mobility group box 1 (HMGB1) is a nuclear protein that, once secreted extracellularly, initiates several inflammatory reactions, and it is involved in the pathogenesis of gastric ulcer. The aim of the present study was to investigate the anti‐inflammatory and anti‐ulcerogenic effects of C‐phycocyanin against ethanol‐induced gastric ulcer targeting HMGB1/NLRP3/NF‐κB pathway. Ulcer induction showed increase in HMGB1 expression through activation of nucleotide‐binding domain and leucine‐rich repeat‐containing protein 3 (NLRP3) inflammasome and nuclear factor kappa p65 (NF‐κB p65). Moreover, oxidative stress and inflammatory markers were elevated in the ulcer‐treated group compared to the normal control group. However, pre‐treatment with C‐phycocyanin significantly reduced HMGB1 expression via suppression of NLRP3/NF‐κB, oxidative markers, IL‐1β, tumour necrosis factor‐α (TNF‐α) and ulcer index value. These results were consistent with histopathological and immunohistochemistry examination. Thus, C‐phycocyanin is a potential therapeutic strategy with anti‐inflammatory and anti‐ulcerogenic effects against ethanol‐induced gastric ulcer.     

Sodium tanshinone IIA silate inhibits oxygen-glucose deprivation/recovery-induced cardiomyocyte apoptosis via suppression of the NF-κB/TNF-α pathway

Background and Purpose

Inhibition of apoptosis may attenuate the irreversible injury associated with reperfusion. In the current study, we focused on the cytoprotective effects and the underlying mechanism of sodium tanshinone IIA silate (STS) against damage induced by oxygen-glucose deprivation/recovery (OGD/R). in H9c2 cardiomyocytes and the underlying mechanisms.

Experimental Approach

We used a model of cardiac ischaemia/reperfusion, OGD/R in H9c2 cardiomyocytes, to assess the cardioprotective effects of STS. Apoptosis of cells was measured with Hoechst 33342-based fluorescence microscopy, and annexin V-FITC-based flow cytometry. Caspase-3 and caspase-8 activities and mitochondrial membrane potential were also measured using commercial kits. TNF-α in the cell culture supernatant fractions were measured with sandwich elisa, and protein levels assayed using Western blot.

Key Results

STS inhibited OGD/R-induced apoptosis by suppressing JNK-mediated activation of NF-κB, TNF-α expression, activation of caspase-3 and caspase-8 and the Bax/Bcl-2 ratio. Additionally, positive feedback between NF-κB and TNF-α and amplification of TNF-α were inhibited, suggesting that STS plays a protective role against apoptosis in cardiomyocytes, even upon activation of pro-inflammatory cytokines. Interestingly, the cytoprotective effects of STS on OGD/R-induced apoptosis and promotion of cell survival were attenuated after inhibition of PI3K.

Conclusion and Implications

The inhibitory effects of STS on TNF-α and positive feedback signalling of the NF-κB/TNF-α pathways may play important roles in myocardial protection against ischaemia/reperfusion. These protective effects of STS are mediated by suppressing JNK activity through activation of the PI3K-Akt pathway.     

Paeoniflorin treatment regulates TLR4/NF-κB signaling,reduces cerebral oxidative stress and improves white matter integrity in neonatal hypoxic brain injury

Neonatal hypoxia/ischemia (H/I), injures white matter, results in neuronal loss, disturbs myelin formation, and neural network development. Neuroinflammation and oxidative stress have been reported in neonatal hypoxic brain injuries. We investigated whether Paeoniflorin treatment reduced H/I-induced inflammation and oxidative stress and improved white matter integrity in a neonatal rodent model. Seven-day old Sprague–Dawley pups were exposed to H/I. Paeoniflorin (6.25, 12.5, or 25 mg/kg body weight) was administered every day via oral gavage from postpartum day 3 (P3) to P14, and an hour before induction of H/I. Pups were sacrificed 24 h (P8) and 72 h (P10) following H/I. Paeoniflorin reduced the apoptosis of neurons and attenuated cerebral infarct volume. Elevated expression of cleaved caspase-3 and Bad were regulated. Paeoniflorin decreased oxidative stress by lowering levels of malondialdehyde and reactive oxygen species generation and while, and it enhanced glutathione content. Microglial activation and the TLR4/NF-κB signaling were significantly down-regulated. The degree of inflammatory mediators (interleukin 1β and tumor necrosis factor-α) were reduced. Paeoniflorin markedly prevented white matter injury via improving expression of myelin binding protein and increasing O1-positive olidgodendrocyte and O4-positive oligodendrocyte counts. The present investigation demonstrates the potent protective efficiency of paeoniflorin supplementation against H/I-induced brain injury by effectually preventing neuronal loss, microglial activation, and white matter injury via reducing oxidative stress and inflammatory pathways.     

Ginsenoside Rg1 exerts neuroprotective effects in 3-nitropronpionic acid-induced mouse model of Huntington’s disease via suppressing MAPKs and NF-κB pathways in the striatum

Huntington’s disease (HD) is one of main neurodegenerative diseases, characterized by striatal atrophy, involuntary movements, and motor incoordination. Ginsenoside Rg1 (Rg1), an active ingredient in ginseng, possesses a variety of neuroprotective effects with low toxicity and side effects. In this study, we investigated the potential therapeutic effects of Rg1 in a mouse model of HD and explored the underlying mechanisms. HD was induced in mice by injection of 3-nitropropionic acid (3-NP, i.p.) for 4 days. From the first day of 3-NP injection, the mice were administered Rg1 (10, 20, 40 mg·kg⁻¹, p.o.) for 5 days. We showed that oral pretreatment with Rg1 alleviated 3-NP-induced body weight loss and behavioral defects. Furthermore, pretreatment with Rg1 ameliorated 3-NP-induced neuronal loss and ultrastructural morphological damage in the striatum. Moreover, pretreatment with Rg1 reduced 3-NP-induced apoptosis and inhibited the activation of microglia, inflammatory mediators in the striatum. We revealed that Rg1 exerted neuroprotective effects by suppressing 3-NP-induced activation of the MAPKs and NF-κΒ signaling pathways in the striatum. Thus, our results suggest that Rg1 exerts therapeutic effects on 3-NP-induced HD mouse model via suppressing MAPKs and NF-κΒ signaling pathways. Rg1 may be served as a novel therapeutic option for HD.