Shu-Ping Zhang

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.

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.

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.

Protocatechuic Acid Induces Angiogenesis through PI3K-Akt-eNOS-VEGF Signalling Pathway

In this study, we sought to elucidate whether protocatechuic acid contributes to induce angiogenesis as well as its mechanisms. To this end, we examined the role of protocatechuic acid on human brain microvascular endothelial cell line (HBMEC) proliferation, invasion and tube formation in in vitro. For the study of mechanisms involved, the phosphoinositide 3 kinase (PI3K)‐Akt inhibitor LY294002, the endothelial nitric oxide synthase (eNOS) inhibitor L‐NAME, vascular endothelial growth factor (VEGF), antagonist sFlt‐1 and VEGF receptor blocker SU‐1498 were used. Proliferation of HBMEC 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 HBMEC was tested by Western blot. Our data suggested that protocatechuic acid induces angiogenesis in vitro by increasing proliferation, invasion and tube formation. VEGF expression was increasing by protocatechuic acid and counteracted by VEGF antagonist sFlt‐1, LY294002 and L‐NAME in HBMEC. Tube formation was increased by protocatechuic acid and counteracted by VEGF receptor blocker‐SU1498, LY294002 and L‐NAME. These data suggest that protocatechuic acid may be a candidate therapy for stroke recovery by promoting angiogenesis via a programmed PI3K/Akt/eNOS/VEGF signalling axis.

Forsythoside B Protects Against Experimental Sepsis by Modulating Inflammatory Factors

The present study investigated the effects of Forsythoside B on an experimental model of sepsis induced by caecal ligation and puncture (CLP) in rats and elucidated the potential mechanism in cultured RAW 264.7 cells. Results showed that Forsythoside B concentration‐dependently down‐regulated the levels of TNF‐α, IL‐6 and high‐mobility group‐box 1 protein (HMGB1) in lipopolysaccharide (LPS)‐stimulated RAW264.7 cells, inhibited the IκB kinase (IKK) pathway and modulated nuclear factor (NF)‐ κB. Intravenous injection (i.v.) of Forsythoside B alone or plus Imipenem reduced serum levels of TNF‐α, IL‐6, HMGB1, triggering receptor expressed on myeloid cells (TREM‐1) and endotoxin, while the serum level of IL‐10 was up‐regulated and myeloperoxidase (MPO) in lung, liver and small intestine was reduced. Meanwhile, i.v. of Forsythoside B alone or plus Imipenem reduced CLP‐induced lethality in rats. These data indicated that the antisepsis effect of Forsythoside B is mediated by decreasing local and systemic levels of a wide spectrum of inflammatory mediators. Its antisepsis mechanism may be that Forsythoside B binds to LPS and reduces the biological activity of serum LPS, and inhibits NF‐κB activition. Our studies enhance the case for the use of Forsythoside B in sepsis. Forsythoside B itself has promise as a therapy for the treatment of sepsis in humans. Copyright

Tricin 7-glucoside protects against experimental cerebral ischemia by reduction of NF-κB and HMGB1 expression

There have been several studies of nuclear factor-κB (NF-κB) and high-mobility group box1 (HMGB1) associated with the pathophysiology of cerebral ischemia. Tricin 7-glucoside, a major bioactive compound extracted from Sedum sarmentosum Bunge. The objectives of this study were to determine the effects of Tricin 7-glucoside on a cultured neuronal cell line, SH-SY5Y in vitro and experimental ischemic stroke in vivo. For oxygen-glucose deprivation (OGD) and tumor necrosis factor-α (TNF-α) stimulated SH-SY5Y cell line in vitro, SH-SY5Y cells were incubated with Tricin 7-glucoside. For in vivo experiment, rats were subjected to middle cerebral artery occlusion (MACO) for 1h, then followed by reperfusion for 23 h. Treatment of SH-SY5Y cells with Tricin 7-glucoside reduced the OGD-induced apoptosis and cytotoxicity, blocked TNF-α-induced NF-κB and IκB-α phosphorylation, and decreased HMGB1 expression. At doses higher than 50mg/kg, Tricin 7-glucoside produced a significant neuroprotective potential in rats with ischemia and reperfusion (I/R). Tricin 7-glucoside (100mg/kg) demonstrated significant neuroprotective activity even after delayed administration at 2h and 4h after I/R. Tricin 7-glucoside 100mg/kg attenuated histopathological damage, decreased brain edema, inhibited NF-κB activation and reduced HMGB1 expression. These data show that Tricin 7-glucoside 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 its protective effects may involve HMGB1 and NF-κB signaling pathway.

Effect of 8-O-acetyl Shanzhiside Methylester Increases Angiogenesis and Improves Functional Recovery after Stroke

We investigated whether 8-O-acetyl shanzhiside methylester (ND01) regulates angiogenesis and thereby improves functional outcome after stroke. Adult male rats were subjected to 1 hr of middle cerebral artery occlusion (MCAO) and reperfusion, and treated with or without different doses (5 and 10 mg/kg) of ND01, starting 24 hr after ischaemia and reperfusion (I/R) and by intravenous injection daily for 14 days. Neurological functional tests were performed and cerebral Evans blue extravasation was measured. Angiogenesis and angiogenic factor expression were measured by immunohistochemistry and Western blot, respectively. The results indicated that ND01 significantly promoted angiogenesis in the ischaemic brain and improved functional outcome after stroke. ND01 also significantly increased vascularization compared with vehicle treatment. ND01 increased the expression of VEGF, Ang1, phosphorylation of Tie2 and Akt VEGF. The Ang1/Tie2 axis and Akt pathways appear to mediate ND01-induced angiogenesis.

Effect of rosmarinic acid on experimental diabetic nephropathy.

Connective tissue growth factor (CTGF) plays a pathogenic role in diabetic nephropathy (DN). Rosmarinic acid (RA) is a naturally occurring phenolic acid. This study was conducted to investigate the efficacy of RA on DN and to elucidate the potential mechanism. High glucose (HG)-stimulated cultured human renal proximal tubular epithelial cells (HK-2) analysed CTGF expression by western blotting, and it was investigated whether extracellular signal-regulated kinase (ERK) signalling pathway was involved. Using streptozotocin (STZ)-induced rat animal models, diabetic rats were randomized to receive intragastric (i.g.) doses of RA. Renal tissue, blood and urine samples were collected to determine biochemical index and analyse protein expression. In vitro study, RA reduced CTGF excretion in HG-induced HK-2 cells through the ERK signalling pathway. In an in vivo study, I.g. of RA 7.5 or 15 mg/kg significantly ameliorated renal function and increased body-weight. Meanwhile, RA reduced renal CTGF expression by immunohistochemical staining and reduced serum levels of CTGF. Besides, there were no significant differences in glycaemia levels between the RA groups compared with the STZ-treated group. Furthermore, RA ameliorated renal pathology. These results suggest that RA 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 RA in the treatment of DN.