Yuyan Zhang

Synergistic protective effect of astragaloside IV–tetramethylpyrazine against cerebral ischemic-reperfusion injury induced by transient focal ischemia

ETHNOPHARMACOLOGICAL RELEVANCE Astragaloside IV and tetramethylpyrazine have been extensively used in the cardio-cerbrovascular diseases of medicine as a chief ingredient of glycoside or alkaloid formulations for the treatment of stroke and myocardial ischemia diseases. AIM OF THE STUDY To investigate the effects of astragaloside IV (ASG IV) and tetramethylpyrazine (TMPZ) on cerebral ischemia-reperfusion (IR) injury model in rat model. MATERIALS AND METHODS Rats were randomly divided into the following five groups: sham group, IR group and treatment group including ASG IV, ASG IV-TMPZ and nimodipine treatment. The therapeutic effect was evaluated by micro-positron emission tomography (Micro-PET) using (18)F-fluoro-2-deoxy-d-glucose. The neurological examination, infarct volume and the levels of oxidative stress- and cell apoptosis-related molecules were assessed. RESULTS Micro-PET imaging showed that glucose metabolism in the right hippocampus was significantly decreased in the IR group compared to the sham group (P<0.01). ASG IV and ASG IV-TMPZ treatments reversed the decreased glucose metabolism in the model group (P<0.05 and P<0.01, respectively). IR induced the increase of Caspase-3 mRNA levels, MDA content and iNOS activity, but it caused the decrease of SOD activity and Bcl-2 expression compared the sham group (P<0.01). ASG IV-TMPZ and ASG IV reversed the IR-induced changes of these parameters, i.e. the down regulation of Caspase-3 mRNA, MDA content and iNOS activity, and the up regulation of SOD activity and Bcl-2 expression (P<0.05). CONCLUSION This study showed that ASG IV-TMPZ played a pivotal synergistic protective role against focal cerebral ischemic reperfusion damage in a rat experimental model.

Lipid-lowering effects of Danhong injection on hyperlipidemia rats.

ETHNOPHARMACOLOGICAL RELEVANCE Danhong injection (DHI), a Chinese medical product extracted from Radix et Rhizoma Salviae Miltiorrhizae (Salvia miltiorrhiza Bge., Labiatae, Danshen in Chinese) and Flos Carthami (Carthamus tinctorius L., Compositae, Honghua in Chinese), has been reported to have anti-inflammatory, anti-oxidative and anti-fibrinolytic properties and is used extensively for the clinical treatment of cardiovascular disease in clinic. This study aimed to investigate the preventive and therapeutic effects of DHI on hyperlipidemia. MATERIALS AND METHODS Forty-eight adult male Sprague-Dawley rats were randomly divided into four groups: normal control (NC), model control (MC) and DHI-treated at doses of 1.0mL/kg and 2.0mL/kg. The effects of DHI on serum triglyceride (TG), total cholesterol (TC), glucose, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were evaluated and insulin was determined by enzyme-linked immunosorbent assay (ELISA). Moreover, the expression of acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), carnitine palmitoyl transferase 1 (CPT1), hydroxymethylglutaryl-CoA reductase (HMGR) and peroxisome proliferator-activated receptor alpha (PPAR-α) in liver were determined by real-time PCR. RESULTS Compared with the MC group, rats treated with DHI had significantly reduced TG, TC, LDL-C and arteriosclerosis index (AI). Expression of FAS and HMGR mRNA was significantly reduced, whereas the CPT1 and PPAR-α were significantly increased. CONCLUSION DHI treatment was accompanied by significantly increased lipolysis in the liver and decreased fatty acid synthesis. The insights gained from this study will improve both understanding of the mechanisms involved in the effect of DHI on hyperlipidemia and the pharmacological rationale for the use of DHI in diseases caused by lipid metabolic disorders.

Evaluation of the hepatoprotective and antioxidant activities of Rubus parvifolius L.

The hepatoprotective and antioxidant activities of the n-butanol extract of Rubus parvifolius L. (RPL), a widely used medicinal plant, were evaluated. Results demonstrated that RPL extract possessed pronounced hepatoprotective effects against carbon tetrachloride (CCl4)-induced hepatic injury in mice, which was at least partially attributed to its strong antioxidant capacity. Treatment with RPL extract markedly attenuated the increases in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels caused by CCl4 intoxication. It also significantly prevented the decrease in superoxide dismutase (SOD) activity and the increase in malondialdehyde (MDA) content of liver tissue. Meanwhile, histopathological changes of hepatic damage were also remarkably ameliorated. Phytochemical analysis based on high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) revealed the presence of various phenolic compounds, including caffeic acid conjugates, ellagic acid glycosides, and flavonol glycosides, which might be responsible for the hepatoprotective and antioxidant activities of RPL.

PET Demonstrates Functional Recovery after Treatment by Danhong Injection in a Rat Model of Cerebral Ischemic-Reperfusion Injury

This study aimed to investigate neuroprotection of Danhong injection (DHI) in a rat model of cerebral ischemia using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET). Method. Rats were divided into 5 groups: sham group, ischemia-reperfusion untreated (IRU) group, DHI-1 group (DHI 1 mL/kg/d), DHI-2 group (DHI 2 mL/kg/d), and DHI-4 group (DHI 4 mL/kg/d). AII the treated groups were intraperitoneally injected with DHI daily for 14 days. The therapeutic effects in terms of cerebral infarct volume, neurological function, and cerebral glucose metabolism were evaluated. Expression of TNF-α and IL-1β was detected with enzyme-linked immunosorbent assay (ELISA). Levels of mature neuronal marker (NeuN), glial marker (GFAP), vascular density factor (vWF), and glucose transporter 1 (GLUT1) were assessed by immunohistochemistry. Results. Compared with the IRU group, rats treated with DHI showed dose dependent reductions in cerebral infarct volume and levels of proinflammatory cytokines, improvement of neurological function, and recovery of cerebral glucose metabolism. Meanwhile, the significantly increased numbers of neurons, gliocytes, and vessels and the recovery of glucose utilization were found in the peri-infarct region after DHI treatment using immunohistochemical analysis. Conclusion. This study demonstrated the metabolic recovery after DHI treatment by micro-PET imaging with 18F-FDG and the neuroprotective effects of DHI in a rat model of cerebral ischemic-reperfusion injury.

Effect of ligustrazine on levels of amino acid neurotransmitters in rat striatum after cerebral ischemia-reperfusion injury

This study aimed to evaluate the effect of ligustrazine on levels of amino acid transmitters in the extracellular fluid of striatum following cerebral ischemia/reperfusion (I/R) in male Sprague-Dawley rats. A microdialysis cannula guide was implanted into the right striatum. After recovery, animals underwent a sham operation or middle cerebral artery occlusion (MCAO). Those that developed cerebral ischemia after MCAO were randomized to receive propylene glycol salt water and ligustrazine respectively. Striatal fluid samples were collected from all animals at 15-min intervals after treatment and were subjected to HPLC analysis of aspartic acid, glutamic acid, taurine, and γ-amino butyric acid. Upon the last sample collection, animals were sacrificed and brain tissue specimens were collected for triphenyltetrazolium chloride staining and NeuN staining. Compared with the sham operation, MCAO induced significant neurological deficits and increased striatal concentrations of the four neurotransmitters assessed in a time-dependent manner (P < 0.01). Ligustrazine effectively attenuated the detrimental effects of MCAO on the brain. These observations suggest that ligustrazine as a novel cerebral infarction-protective agent may have potential clinical implications for I/R-related brain damage.

Effects of Danhong Injection on platelet aggregation in hyperlipidemia rats

ETHNOPHARMACOLOGICAL RELEVANCE Danhong Injection (DHI), a Chinese medical product extracted from Radix et Rhizoma Salviae Miltiorrhizae (Salvia miltiorrhiza Bge., Labiatae, Danshen in Chinese) and Flos Carthami (Carthamus tinctorius L., Compositae, Honghua in Chinese), has been reported to have effects on inflammatory, anti-fibrinolytic properties, antithrombotic and decrease blood-lipid. It is extensively used for the clinical treatment of cardiovascular disease. This study aimed to investigate the effects of DHI on blood-lipid levels and platelet aggregation rate in hyperlipidemia rats. MATERIALS AND METHODS Rats were randomly divided into 6 groups: normal control (NC), model control (MC), DHI-treated control at doses of 1.0mL/kg, 2.0mL/kg, 4.0mL/kg, respectively, and Simvastatin positive control at dose of 2.0mg/kg. All DHI treated groups were intraperitoneally injected for 7 days. The effects of DHI on serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) were evaluated. And platelet activating factor (PAF), platelet membrane glycoprotein IIb/IIIa (GP IIb/IIIa) and 6-keto-prostaglandin F1а (6-K-PGF1а) were determined by enzyme-linked immunosorbent assay (ELISA). Moreover, the expression of prostaglandin I-2 (PGI2), prostaglandin E-2 (PGE2) and thromboxane A2 (TXA2) in liver was determined by real-time PCR. RESULTS Compared with the MC group, the rats treated with DHI had significantly reduced TC, TG, LDL-C, FIB, GP IIb/IIIa and platelet aggregation. Meanwhile, the thrombin time (TT), activated partial thrombin time (APTT), prothrombin time (PT), 6-K-PGF1а was significantly increased. Expression of PGI2 and PGE2 mRNA was significantly increased, whereas the TXA2 was significantly reduced. CONCLUSIONS This study demonstrated that the blood lipid and platelet aggregation has a regulatory effect after DHI treatment. The insights gained from this study will improve understanding of the mechanisms involved in the effect of DHI on hyperlipidemia and the pharmacological rationale for the use of DHI in diseases caused by formation of thrombosis and lipid metabolic disorders.

Effects of Active Components of Fuzi and Gancao Compatibility on Bax, Bcl-2, and Caspase-3 in Chronic Heart Failure Rats

Hypaconitine (HA) and glycyrrhetinic acid (GA) are active components of Fuzi (Aconitum carmichaelii) and Gancao (Glycyrrhiza uralensis Fisch); they have been used in compatibility for chronic heart failure (CHF) from ancient times. The purpose of the present research was to explore whether apoptosis pathways were related with the protective effects of HA + GA against CHF rats or not. The rats were progressed with transverse-aortic constriction (TAC) operation for 4 weeks to build the CHF state, and then the Digoxin (1 mg/kg), HA (2.07 mg/kg), GA (25 mg/kg), and HA (2.07 mg/kg) + GA (25 mg/kg) were orally administrated to rats for 1 week. The levels of BNP and cTnI in the plasma were decreased in the HA + GA group, and the heart/body weight ratio (H/B) and left ventricular (LV) parameters of transthoracic echocardiography were also declined; moreover, the expressions of Bax, Bcl-2, and caspase-3 were all improved in the HA + GA group than other groups in the immunohistochemistry and western blot methods. In general, the data suggested that Fuzi and Gancao compatibility could protect the CHF rats from apoptosis, which provided a strong evidence for further searching for mechanisms of them.

Influence of liquid lipid content on the properties of puerarin-loaded lipid nanoparticles

The present study described the fabrication and characterization of puerarin-loaded lipid nanoparticles with blends of glyceryl monostearate (solid lipid phase) and DELIOS® MCT (liquid lipid phase) as the lipid matrices. Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) were prepared via controlling the ratio of liquid lipid to solid lipid. The drug–lipid compatibility was evaluated via theoretical calculation of solubility parameters and X-ray diffraction analysis. The influence of liquid lipid content on the particle size, morphology, stability, drug loading properties of the lipid nanoparticles and in vitro release behavior of puerarin was investigated. Both SLN and NLC exhibited good stability and spherical shapes, and no significant difference in particle size occurred for the NLC series. The drug loading capacity and entrapment efficiency of the lipid nanoparticles were affected with increasing the liquid lipid content, and the presence of liquid lipid had a positive effect on ...

Danhong Injection Combined With t-PA Improves Thrombolytic Therapy in Focal Embolic Stroke

Background: Hemorrhagic transformation, neurotoxicity, short treatment time windows, and other defects are considered as the major limitations for the thrombolytic therapy. This study is devoted to figure out whether Danhong injection (DHI) combined with tissue-plasminogen activator (t-PA) could extend the treatment time windows and ameliorate brain injury, hemorrhagic complication and BBB disruption after focal embolic stroke. Methods: In vitro, the combined concentrations of DHI and t-PA were added to wells reacted with plasminogen and D-Val-Leu-Lys-AMC. The optimum ratio of the combination of DHI plus t-PA was explored by detecting relative fluorescent. In vivo experiments, we firstly investigated the optimal dose of t-PA and Danhong injection for focal embolic stroke. The neurological deficit score, infarct volume and brain edema were assessed. Secondly, we proved that the combination group extended the thrombolytic window for treatment of focal embolic stroke. The neurological deficit score, infarct volume, brain edema and hemorrhagic complication were assessed, while levels of BAX, Bcl-2 and caspase-3 in brain tissue were analyzed by real-time polymerase chain reaction. Finally, to ask whether combination therapy with DHI plus t-PA protected the blood–brain barrier in a rat model of focal embolic stroke, neurological deficit score, ELISA, RT-PCR, western blot and fluorescence were used to detect the indicators of blood–brain barrier, such as tight junction protein, blood–brain barrier permeability and related gene expression. Results: In vitro, plasmin activity assays showed that the combination of t-PA with DHI at about 1:1.6 w/v ratio increased by almost 1.4-fold the plasmin-generating capability of t-PA. In vivo experiments, the results showed that the combination of Danhong injection (4 mL/kg) and t-PA (2.5 mg/kg) could extend the t-PA treatment time windows to 4.5 h. And the combination t-PA (2.5 mg/kg) with DHI (4 mL/kg) ameliorated neurological score, cerebral infarction, brain edema, brain hemorrhage, and BBB disruption. Conclusion: Combination therapy with Danhong injection (4 mL/kg) plus t-PA (2.5 mg/kg) could extend the t-PA treatment time windows to 4.5 h, ameliorate BBB disruption, reduce infarction, brain swelling and hemorrhage after ischemic stroke.

Glycyrrhetinic acid protects H9c2 cells from oxygen glucose deprivation-induced injury through the PI3K/AKt signaling pathway

Glycyrrhetinic acid (GA) is an ingredient of triterpene saponins found in Gancao (Radix Glycyrrhizae). Here, we investigated the protective effects of GA in H9c2 cells, and explored its possible mechanism of action. Different concentrations of GA were used to treat H9c2 cells under oxygen glucose deprivation. We analyzed cell necrosis and apoptosis using optical microscopy, Hoechst 33342 staining, FITC-annexin V/PI double-staining and lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB) and interleukin (IL)-1β assays. Changes in related pro-apoptosis and anti-apoptosis proteins were detected by Western blot. Optical microscopy showed that GA improved cell morphology, including cell shrinkage, cauliflower-like membrane blebbing, and even some cell debris. Meanwhile, GA also ameliorated cell nuclei characteristics such as nucleus size, chromatin condensation and bright staining from Hoechst 33342 staining. GA also lowered the apoptotic rate and the levels of LDH, CK-MB and IL-1β in a dose-dependent manner. Furthermore, GA treatment increased Bcl-2 protein expression and decreased caspase-8 and Bax protein expression, while elevating the Bcl-2/Bax ratio. GA preconditioning increased p-AKt protein expression; however, after adding LY 294002, the p-AKt expression decreased obviously. Our results demonstrated that GA could protect H9c2 cells from apoptosis in a dose-dependent manner, and the potential mechanism might be related to the PI3K/AKt signaling pathway.