Wanglin Jiang

Rosmarinic acid protects against experimental diabetes with cerebral ischemia: relation to inflammation response.

BackgroundInflammatory activation plays a vital role in the pathophysiological mechanisms of stroke, exerting deleterious effects on the progression of tissue damage and may lead to the vascular damage in diabetes. The objectives of this study were to determine the effects of rosmarinic acid (RA) on a cultured neuronal cell line, SH-SY5Y in vitro and experimental ischemic diabetic stroke in vivo.MethodsFor oxygen-glucose deprivation (OGD) and tumor necrosis factor-α (TNF-α) stimulated SH-SY5Y cell line in vitro, SH-SY5Y cells were incubated with RA. For an in vivo experiment, diabetic rats were subjected to middle cerebral artery occlusion (MACO) for 40 minutes followed by reperfusion for 23 h.ResultsTreatment of SH-SY5Y cells with RA reduced the OGD-induced apoptosis and cytotoxicity, blocked TNF-α-induced nuclear transcription factor κB (NF-κB) activation, and decreased high-mobility group box1 (HMGB1) expression. At doses higher than 50 mg/kg, RA produced a significant neuroprotective potential in rats with ischemia and reperfusion (I/R). RA (50 mg/kg) demonstrated significant neuroprotective activity even after delayed administration at 1 h, 3 h and 5 h after I/R. RA 50 mg/kg attenuated histopathological damage, decreased brain edema, inhibited NF-κB activation and reduced HMGB1 expression.ConclusionThese data show that RA protects the brain against I/R injury with a favorable therapeutic time-window by alleviating diabetic cerebral I/R injury and attenuating blood–brain barrier (BBB) breakdown, and its protective effects may involve HMGB1 and the NF-κB signaling pathway.

Effect of loganin on experimental diabetic nephropathy.

Connective tissue growth factor (CTGF) plays a pathogenic role in diabetic nephropathy (DN). Loganin, an iridoid glucoside compound was isolated from Cornus officinalis Sieb. et Zucc. This study was conducted to investigate the efficacy of loganin on DN and to elucidate the potential mechanism. High glucose (HG) stimulated cultured human renal proximal tubular epithelial cells (HK-2) analyzed CTGF expression by Western blotting and investigated whether extracellular signal-regulated kinase (ERK) signaling pathway was involved. Streptozotocin (STZ)-induced experimental DN, randomized to receive intragastric (i.g.) of loganin. Renal tissue, blood and urine samples were collected to determine and analyze. In vitro study, loganin reduced CTGF excretion in HG-induced HK-2 cells through the ERK signaling pathway. In vivo study, I.g. of loganin 5 mg/kg or 10 mg/kg significantly ameliorated renal function and increased body weight. Meanwhile, loganin reduced renal CTGF expression by immunohistochemical staining, reduced serum levels of CTGF. Besides, there were no significant differences in blood sugar levels between the loganin groups compared to the STZ-treated group. Furthermore, loganin ameliorated renal pathology. These results suggested that loganin exerts an early renal protective role to DN. Inhibition of CTGF may be a potential target in DN therapy, which highlights the possibility of using loganin to treat DN.

Inhibition of nuclear factor-κB by 6-O-acetyl shanzhiside methyl ester protects brain against injury in a rat model of ischemia and reperfusion

BackgroundRecent studies have demonstrated an inflammatory response associated with the pathophysiology of cerebral ischemia. The beneficial effects of anti-inflammatory drugs in cerebral ischemia have been documented. When screening natural compounds for drug candidates in this category, we isolated 6-O-acetyl shanzhiside methyl ester (ND02), an iridoid glucoside compound, from the leaves of Lamiophlomis rotata (Benth.) Kudo. The objectives of this study were to determine the effects of ND02 on a cultured neuronal cell line, SH-SY5Y, in vitro, and on experimental ischemic stroke in vivo.MethodsFor TNF-α-stimulated SH-SY5Y cell line experiments in vitro, SH-SY5Y cells were pre-incubated with ND02 (20 μM or 40 μM) for 30 min and then incubated with TNF-α (20 ng/ml) for 15 min. For in vivo experiments, rats were subjected to middle cerebral artery occlusion (MCAO) for 1 h followed by reperfusion for 23 h.ResultsND02 treatment of SH-SY5Y cell lines blocked TNF-α-induced nuclear factor-κB (NF-κB) and IκB-α phosphorylation and increased Akt phosphorylation. LY294002 blocked TNF-α-induced phosphorylation of Akt and reduced the phosphorylation of both IκB-α and NF-κB. At doses higher than 10 mg/kg, ND02 had a significant neuroprotective effect in rats with cerebral ischemia and reperfusion (I/R). ND02 (25 mg/kg) demonstrated significant neuroprotective activity even after delayed administration 1 h, 3 h and 5 h after I/R. ND02, 25 mg/kg, attenuated histopathological damage, decreased cerebral Evans blue extravasation, inhibited NF-κB activation, and enhanced Akt phosphorylation.ConclusionThese data show that ND02 protects brain against I/R injury with a favorable therapeutic time-window by alleviating cerebral I/R injury and attenuating blood-brain barrier (BBB) breakdown, and that these protective effects may be due to blocking of neuronal inflammatory cascades through an Akt-dependent NF-κB signaling pathway.

Astilbin protects diabetic rat heart against ischemia–reperfusion injury via blockade of HMGB1-dependent NF-κB signaling pathway

Astilbin, a flavonoid compound was isolated from the rhizome of Smilax china L. In this study, we investigated the anti-myocardial ischemia and reperfusion (I/R) injury effect of Astilbin on diabetic rats in vivo and elucidated the potential mechanism in vitro. The results showed that Astilbin significantly attenuated hypoxia-induced cell injury in a concentration-dependent manner. Treatment of H9c2 cells with Astilbin at 15 μM blocked nuclear factor kappaB (NF-κB) phosphorylation by blocking High-mobility group box protein 1 (HMGB1) expression. Treatment of diabetic rats with Astilbin by intravenous injection (i.v.) at a single dose of 50 mg/kg protected the rats from myocardial I/R injury as indicated by decreasing infarct volume, improving hemodynamics and reducing myocardial damage, and also lowered serum levels of pro-inflammatory factors, reduced HMGB1 and phosphorylated NF-κB expression in ischemic myocardial tissue from diabetic rats. Additionally, treatment of diabetic rats with Astilbin at dose of 50 mg/kg by i.v. for continuous 14 days attenuated cardiac remodeling in the model myocardial I/R injury. These protective effects suggested that Astilbin might be due to block of the myocardial inflammatory cascade via the HMGB1-dependent NF-κB signaling pathway.

Cornin ameliorates cerebral infarction in rats by antioxidant action and stabilization of mitochondrial function.

This study was conducted to investigate the efficacy of cornin, an iridoid glycoside, in an experimental cerebral ischemia induced by middle cerebral artery occlusion (MCAO) and reperfusion (I/R), and to elucidate the potential mechanism. Adult male Sprague‐Dawley rats were subjected to MCAO for 1 h, then reperfusion for 23 h. Behavioral tests were used to evaluate the damage to central nervous system. The cerebral infarct volume and histopathological damage were assessed to evaluate the brain pathophysiological changes. Spectrophotometric assay methods were used to determine the activities of superoxide dismutase (SOD) and glutathione‐peroxidase (GPx). Contents of malondialdehyde (MDA), the generation of reactive oxygen species (ROS) as well as respiratory control ratio and respiratory enzymes of the brain mitochondria were also determined. The results showed that cornin significantly decreased neurological deficit scores, and reduced cerebral infarct volume and degenerative neurons. Meanwhile, cornin significantly increased the brain ATP content, improved mitochondrial energy metabolism, inhibited the elevation of MDA content and ROS generation, and attenuated the decrease of SOD and GPx activities in brain mitochondria. These findings indicate that cornin has protective potential against cerebral ischemia injury and its protective effects may be due to amelioration of cerebral mitochondrial function and its antioxidant property. Copyright

Cardioprotection of Asperosaponin X on experimental myocardial ischemia injury

BACKGROUND Asperosaponin X was isolated from the roots of Dipsacus asper. In this study, we investigated the anti-myocardial ischemia and reperfusion (I/R) injury effects of Asperosaponin X in vivo and elucidated the potential mechanism in vitro. RESULTS Asperosaponin X significantly attenuated hypoxia-induced cytotoxicity in a concentration-dependent manner in H9c2 cells. Treatment of H9c2 cells with Asperosaponin X 5 μM or 10 μM blocked TNF-α-induced nuclear factor kappaB (NF-κB) phosphorylation by blocking HMGB1 expression. Treatment of rats with Asperosaponin X 10mg/kg, (i.v.) protected the animals from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics and reduction of myocardial damage severity. Treatment with Asperosaponin X also lowered serum levels of pro-inflammatory factors and reduced High mobility group box-1 protein (HMGB1), phosphorylated IκB-α and NF-κB expression in ischemic myocardial tissue. Additionally, continuous i.v. of Asperosaponin X 14 days attenuated cardiac remodeling. CONCLUSIONS These protective effects suggested that Asperosaponin X may be due to block of myocardial inflammatory cascades through an HMGB1-dependent NF-κB signaling pathway.

Ponatinib ameliorates pulmonary fibrosis by suppressing TGF-β1/Smad3 pathway.

TGF-β1/Smad3 pathway plays a key role in the pathogenesis of idiopathic pulmonary fibrosis, including lung fibroblasts proliferation and epithelial cell aberrant activation. Ponatinib is a multi-targeted tyrosine-kinase inhibitor. However, whether Ponatinib has anti-fibrotic functions is unknown. In this study, the effects of Ponatinib on TGF-β1-mediated epithelial-mesenchymal transition (EMT) in A549 cells, on the proliferation of human lung fibroblasts (HLF-1), on the apoptosis of human type I alveolar epithelial cells (AT I) in vitro, and on bleomycin (BLM)-induced pulmonary fibrosis was investigated in vivo. Treatment with Ponatinib resulted in a reduction of EMT in A549 cells with a decrease in vimentin and p-Smad3, whereas an increase in E-cadherin. Apoptosis of AT I was attenuated with an increase in the Bcl-2/Bax ratio. HLF-1 proliferation was reduced with a decrease in PDGF-BB and FGF-2 expressions. Treatment with Ponatinib resulted in an amelioration of the BLM-induced pulmonary fibrosis in rats with reductions of the pathological score, collagen deposition, p-Smad3, α-SMA, PDGF-BB and FGF-2 expression. In summary, Ponatinib reversed the EMT, inhibited the apoptosis of AT I, as well as HLF-1 proliferation and prevented pulmonary fibrosis by suppressing the TGF-β1/Smad3 pathway.

Protocatechuic Aldehyde Protects against Experimental Sepsis In Vitro and In Vivo

Recent studies have demonstrated that nuclear factor-κB (NF-κB) and high-mobility group box 1 (HMGB1) are associated with the pathophysiology of sepsis. The present study was carried out to investigate the effects of protocatechuic aldehyde (PA) on an experimental model of sepsis induced by caecal ligation and puncture (CLP) in rats and to elucidate the potential mechanism in the cultured murine macrophage cell line, RAW264.7 cells. Treatment of RAW 264.7 cells with PA blocked TNF-α-induced NF-κB phosphorylation and decreased HMGB1 expression. Septic rats received doses of 50 mg of PA alone or plus Imipenem by intravenous bolus injection into the tail vein. The results showed that PA reduced serum levels of HMGB1 and triggering the receptor expressed on myeloid cells, it attenuated myeloperoxidase in the lung, liver and small intestine, while it up-regulated serum level of IL-10. Meanwhile, PA alone or plus Imipenem reduced CLP-induced lethality in septic rats. These data indicate that the anti-septic effect of PA is mediated by decreasing local and systemic levels of a wide spectrum of inflammatory mediators. The protective effects of PA might block the inflammatory cascades through HMGB1 and NF-κB signalling pathway. Our studies enhance the case for the use of PA in sepsis, and PA therefore seems promising in the treatment of sepsis in human beings.

Curculigoside A induces angiogenesis through VCAM-1/Egr-3/CREB/VEGF signaling pathway.

Curculigoside A may be a powerful way of protecting the brain against a wide variety of injury. In the present study, we sought to elucidate whether Curculigoside A contributes to induce angiogenesis and its mechanisms. To this end, we examined the role of Curculigoside A on proliferation, invasion, and tube formation in the human brain microvascular endothelial cell line (HBMEC) in vitro. For studying mechanism, the cAMP response element-binding protein (CREB) inhibitor 2-naphthol-AS-E-phosphate (KG-501), early growth response 3 (Egr-3) siRNA, vascular endothelial growth factor (VEGF) antagonist sFlt-1 and VEGF receptor 2 (VEGFR2) blocker SU-1498 were used. Human brain microvascular endothelial cell line (HMBEC) proliferation was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Scratch adhesion test was used to assess the ability of invasion. A matrigel tube formation assay was performed to test capillary tube formation ability. Vascular cell adhesion molecule 1 (VCAM-1)/Egr-3/CREB/VEGF pathway activation in HMBEC was tested by Western blot analysis. Our data suggested that Curculigoside A induced angiogenesis in vitro by enhancing the proliferation, invasion and tube formation. VEGF expression was increased by Curculigoside A and counteracted by the soluble VEGF receptor 1 (sFlt-1, VEGF antagonist) and KG-501 in HMBEC. Tube formation was enhanced by Curculigoside A and counteracted by VEGF receptor blocker-SU1498, KG-501 and Egr-3 siRNA. It may be suggested that Curculigoside A induces angiogenesis in vitro via a programed VCAM-1/Egr-3/CREB/VEGF signaling axis.

Cornin induces angiogenesis through PI3K-Akt-eNOS-VEGF signaling pathway

In the present study, we sought to elucidate whether Cornin contributes to induce angiogenesis and its mechanisms. To this end, we examined the role of Cornin on human brain microvascular endothelial cell line (HBMEC) proliferation, invasion, and tube formation in in vitro. For study of mechanism, the phosphoinositide 3 kinase (PI3K)-Akt inhibitor LY294002, endothelial nitric oxide synthase (eNOS) inhibitor L-NAME, vascular endothelial growth factor (VEGF) antagonist sFlt-1 and VEGF receptor blocker SU-1498 were used. HMBEC proliferation was tested by MTT. Scratch adhesion test was used to assess the ability of invasion. A matrigel tube formation assay was performed to test capillary tube formation ability. PI3K-Akt-eNOS-VEGF pathway activation in HMBEC was tested by Western blot. Our data suggested that Cornin induces angiogenesis in vitro by increasing proliferation, invasion and tube formation. VEGF expression was increasing by Cornin and counteracted by VEGF antagonist sFlt-1, LY294002 and L-NAME in HMBEC. Tube formation was increased by Cornin and counteracted by VEGF receptor blocker-SU1498, LY294002 and L-NAME. It may be suggested that Cornin induces angiogenesis in vitro via a programmed PI3K/Akt/eNOS/VEGF signaling axis.