Hai-Bo Zhu

Fucoidan, a sulfated polysaccharide from brown algae, against myocardial ischemia-reperfusion injury in rats via regulating the inflammation response.

The aim of the study was to determine the effects of fucoidan on rat myocardial ischemia-reperfusion (I/R) model and elucidate the potential mechanisms. Myocardial I/R injury was induced by the occlusion of left anterior descending coronary artery for 30 min followed by reperfusion for 2h. After 2h reperfusion, hemodynamics parameters were detected. Blood samples were collected to determine serum levels of tumor necrosis factor-α (TNF-α) and interleukin 6, 10 (IL-6, 10). Hearts were harvested to assess histopathological changes, infarct size (IS), and the content of myeloperoxidase (MPO). The expression of high-mobility group box 1 (HMGB1), phosphor-IκB-α and phosphor-nuclear factor kappa B (NF-κB) were assayed by western blot. Compared with control group, treatment with fucoidan improved left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and the contractility index (P<0.05, P<0.01). Fucoidan reduced the myocardial IS, the levels of TNF-α and IL-6, and the activity of MPO (P<0.05, P<0.01). Fucoidan down-regulated the expression of HMGB1, phosphor-IκB-α and NF-κB, but increased the content of IL-10 when compared with control (P<0.05, P<0.01). Besides, the infiltration of polymorph nuclear leukocytes (PMNs) and histopathological damages in myocardium were decreased in fucoidan treated groups (PMNs, P<0.05, P<0.01). These findings revealed that the administration of fucoidan could regulate the inflammation response via HMGB1 and NF-κB inactivation in I/R-induced myocardial damage.

In vitro and in vivo antifibrotic effects of rosmarinic acid on experimental liver fibrosis.

This study was carried out to investigate whether rosmarinic acid (RA) has antifibrotic effect on experimental liver fibrosis in vitro and in vivo and its possible mechanism. Culture of hepatic stellate cells (HSCs) determine proliferation and expression of transforming growth factor-beta1 (TGF-beta1), connective transforming growth factor (CTGF) and alpha-smooth muscle actin (alpha-SMA). In carbon tetrachloride (CCL(4))-induced rat liver fibrosis model, determined biochemical indicator, liver fibrosis grade and histopathological changes, immunohistochemical detected liver TGF-beta1 and CTGF expression. The results indicated that RA could inhibit HSCs proliferation, inhibit TGF-beta1, CTGF and alpha-SMA expression in cultured HSCs. It has marked evident in reducing fibrosis grade, ameliorating biochemical indicator and histopathological morphology, reducing liver TGF-beta1 and CTGF expression in CCL(4)-induced liver fibrosis. These findings suggest that RA has potentially conferring antifibrogenic effects.

Paeoniflorin Inhibits Systemic Inflammation and Improves Survival in Experimental Sepsis

The present study was carried out to investigate the effects of paeoniflorin in cultured RAW264.7 cell line as well as in an experimental model of sepsis induced by cecal ligation and puncture, and intraperitoneal injection (i.p.) of lipopolysaccharide in rats. Results showed that paeoniflorin concentration-dependently down-regulated the levels of TNF-alpha, IL-6 and high-mobility group-box 1 protein in lipopolysaccharide-induced RAW264.7 cell, inhibited the IkappaB kinase pathway and modulated NF-kappaB. Intravenous injection (i.v.) of paeoniflorin alone or in combination with imipenem reduced i.p. of lipopolysaccharide or cecal ligation and puncture-induced lethality in rats. In addition, serum levels of TNF-alpha, IL-6, high-mobility group-box 1 protein, triggering receptor expressed on myeloid cells and endotoxin were down-regulated; by contrast, serum levels of IL-10 were up-regulated. Amelioration of hemodynamics, decrease of enzyme levels, decrease of myeloperoxidase in lung, liver, and small intestine were also found after paeoniflorin injection. These data indicate that the anti-sepsis effect of paeoniflorin was mediated by decreasing local and systemic levels of a wide spectrum of inflammatory mediators. This work provides the first evidence that paeoniflorin has the capacity to inactivate inflammatory response in sepsis and the anti-inflammatory mechanism of paeoniflorin may inhibit activation of the NF-kappaB pathway by inhibiting IkappaB kinase activity.

Rosmarinic acid protects against experimental sepsis by inhibiting proinflammatory factor release and ameliorating hemodynamics.

The present study was to investigate the effects of rosmarinic acid (RA) in cultured RAW264.7 cells and experimental model of sepsis induced by cecal ligation and puncture in rats and the potential mechanism. Results showed that RA concentration dependently down-regulated the levels of TNF-&agr;, IL-6, and high-mobility group box 1 protein in LPS-induced RAW264.7 cells, inhibited the I&kgr;B kinase pathway, and modulated nuclear factor-&kgr;B. Intravenous injection of RA alone or in combination with imipenem reduced cecal ligation and puncture-induced lethality in rats. In addition, serum levels of TNF-&agr;, IL-6, high-mobility group box 1 protein, triggering receptor expressed on myeloid cells, and endotoxin were down-regulated; in contrast, serum level of IL-10 was up-regulated. Amelioration of hemodynamics and decrease in serum enzyme activities and myeloperoxidase in lung, liver, and small intestine were also observed after RA injection. These data indicate that the antisepsis effect of RA was mediated by decreasing local and systemic levels of a wide spectrum of inflammatory mediators. This article provides the first evidence that RA has the capacity to inactivate inflammatory response in sepsis. The anti-inflammatory mechanism of RA may inhibit activation of the nuclear factor- &kgr;B pathway by inhibiting I&kgr;B kinase activity.

Cardioprotection with forsythoside B in rat myocardial ischemia-reperfusion injury: relation to inflammation response.

The present study was undertaken to examine the effect of forsythoside B (FB) on rat myocardial ischemia-reperfusion (I/R) model and elucidate the potential mechanism. Left ventricular systolic pressure (LVSP) and +/-dp/dt(max) were detected. Blood samples were collected to determine serum levels of troponin T (Tn-T), TNF-alpha and IL-6. Hearts were harvested to assess histopathological change and infarct size, determine content of MDA, myeloperoxidase (MPO), SOD and GPx activities, analyze expression of high-mobility group box 1 (HMGB1), phosphor-I kappaB-alpha and phosphor-nuclear factor kappaB (NF-kappaB) in ischemic myocardial tissue by Western blot. Compared with control group, rats treatment with FB showed a significant recovery in myocardial function with improvement of LVSP and +/-dp/dt(max). The myocardial infarct volume, serum levels of Tn-T, TNF-alpha and IL-6, content of MDA and MPO activity in myocardial tissue were all reduced, protein expression of HMGB1, phosphor-I kappaB-alpha and phosphor-NF-kappaB were down-regulated, while attenuated the decrease of SOD and GPx activities. Besides, the infiltration of polymorph nuclear leukocytes (PMNs) and histopathological damages in myocardium were decreased in FB treated groups. These findings suggested that FB rescued cardiac function from I/R injury by limiting inflammation response and its antioxidant properties.

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 1u2009h, then reperfusion for 23u2009h. 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

BACKGROUNDnAsperosaponin 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.nnnRESULTSnAsperosaponin 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.nnnCONCLUSIONSnThese 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.