salvianolic-acid-a and Infarction--Middle-Cerebral-Artery

Toll-like receptor 2 and Toll-like receptor 4 (TLR2/4) on microglia have been found as important regulators in the inflammatory response during cerebral ischemia/reperfusion (I/R). In China, traditional Chinese medicine Salvia miltiorrhiza (danshen) and its some components are considered to be effective in rescuing cerebral I/R injury through clinical practice.. Here we examined the effect of Salvianolic acid A (SAA), a monomer compound in the water extract of Salvia miltiorrhiza, on TLR2/4 of microglia and its mediated inflammatory injury during cerebral I/R in vivo and in vitro.. For exploring the effect of SAA on cerebral I/R and TLR2/4, classic middle cerebral artery occlusion (MCAO) model and oxygen glucose deprivation / reoxygenation (OGD/R) model of co-culture with primary hippocampal neurons and microglia in vitro were used. Signal pathway research and gene knockout have been applied to further explain its mechanism.. The evaluation indexes of I/R injury included infarct size, edema degree and pathology as well as primary hippocampal neurons and microglia culture, ELISA, western, RT-PCR, HE staining, immunofluorescence, flow cytometry, siRNA gene knockout were also employed.. SAA significantly improved the degree of brain edema and ischemic area in I/R rats accompanied by decreases in levels of interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α). Pathological staining revealed that SAA could reduce inflammatory cell infiltration and mcirogila activation after reperfusion. Both protein and gene expression of TLR2 and TLR4 in ischemic hemisphere were obviously inhibited by SAA treatment while changes were not found in the non-ischemic hemisphere. In order to further study its mechanism, OGD/R model was used to mimic inflammatory damage of ischemic tissue by co-culturing primary rat hippocampal neurons and microglial cells. It was found that SAA also inhibited the protein and gene expression of TLR2 and TLR4 after OGD/R injury in microglia. After TLR2/4 knockout, the inhibitory effect of SAA on IL-1β and TNF-α levels in cell supernatant and neuron apoptosis were significantly weakened in each dose group. Moreover, expression levels of myeloid differentiation factor 88 (MyD88), NFκB, IL-1β and IL-6 in TLR2/4 mediated inflammatory pathway were reduced with SAA treatment.. SAA could significantly reduce the inflammatory response and injury in cerebral ischemia-reperfusion in vivo and in vitro, and its mechanism may be through the inhibition of TLR2/4 and its related signal pathway.

Topics: Animals; Brain Ischemia; Caffeic Acids; Infarction, Middle Cerebral Artery; Inflammation; Lactates; Male; Microglia; Myeloid Differentiation Factor 88; NF-kappa B; Rats; Reperfusion Injury; Signal Transduction; Toll-Like Receptor 2; Toll-Like Receptor 4

Salvianolic acid A (SAA), a water-soluble phenolic acid isolated from the root of Dan Shen, displays distinct antioxidant activity and effectiveness in protection against cerebral ischemia/reperfusion (I/R) damage. However, whether SAA can enter the central nervous system and exert its protective effects by directly targeting brain tissue remains unclear. In this study, we evaluated the cerebral protection of SAA in rats subjected to transient middle cerebral artery occlusion (tMCAO) followed by reperfusion. The rats were treated with SAA (5, 10 mg/kg, iv) when the reperfusion was performed. SAA administration significantly decreased cerebral infarct area and the brain water content, attenuated the neurological deficit and pathology, and enhanced the anti-inflammatory and antioxidant capacity in tMCAO rats. The concentration of SAA in the plasma and brain was detected using LC-MS/MS. A pharmacokinetic study revealed that the circulatory system exposure to SAA was equivalent in the sham controls and I/R rats, but the brain exposure to SAA was significantly higher in the I/R rats than in the sham controls (fold change of 9.17), suggesting that the enhanced exposure to SAA contributed to its cerebral protective effect. Using a GC/MS-based metabolomic platform, metabolites in the serum and brain tissue were extracted and profiled. According to the metabolomic pattern of the tissue data, SAA administration significantly modulated the I/R-caused perturbation of metabolism in the brain to a greater extent than that in the serum, demonstrating that SAA worked at the brain tissue level rather than the whole circulation system. In conclusion, a larger amount of SAA enters the central nervous system in ischemia/reperfusion rats to facilitate its protective and regulatory effects on the perturbed metabolism.

Topics: Animals; Biological Availability; Brain; Caffeic Acids; Chromatography, Liquid; Cytoprotection; Disease Models, Animal; Gas Chromatography-Mass Spectrometry; Infarction, Middle Cerebral Artery; Injections, Intravenous; Lactates; Male; Metabolomics; Neuroprotective Agents; Rats, Sprague-Dawley; Reperfusion Injury; Tandem Mass Spectrometry

Inflammatory reactions induced by microglia in the brain play crucial roles in ischemia/reperfusion (I/R) cerebral injuries. Microglia activation has been shown to be closely related to TLR4/NF-κB signal pathways. Salvianolic acids for injection (SAFI) have been used in clinical practice to treat ischemic stroke with reported neuroprotective effects; however, the underlying mechanisms are still uncertain.. First, we studied the effect of SAFI on inflammatory responses in LPS-stimulated BV-2 microglia. Then, to discover whether the beneficial in vitro effects of SAFI lead to in vivo therapeutic effects, an MCAO (Middle cerebral artery occlusion) rat model was further employed to elucidate the probable mechanism of SAFI in treating ischemic stroke. Rats in the SAFI group were given SAFI (23 or 46mg/kg) before I/R injury.. The results showed that SAFI treatment significantly decreased neuroinflammation and the infarction volume compared with the vehicle group. Activation of microglia cells was reduced, and TLR4/NF-κB signals, which were markedly inhibited by SAFI treatment in ischemic hemisphere, were accompanied by reduced expression and release of cytokines IL-1β and IL-6.. This study provides evidence that SAFI effectively protects the brain after cerebral ischemia, which may be caused by attenuating inflammation in microglia.

Topics: Alkenes; Animals; Brain Ischemia; Disease Models, Animal; Dose-Response Relationship, Drug; Infarction, Middle Cerebral Artery; Inflammation; Interleukin-1beta; Interleukin-6; Male; Microglia; Neuroprotective Agents; NF-kappa B; Polyphenols; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Stroke; Toll-Like Receptor 4

Salvianolic acid A (SAA) is obtained from Chinese herb Salviae Miltiorrhizae Bunge (Labiatae), has been reported to have the protective effects against cardiovascular and neurovascular diseases.. The aim of present study was to investigate the relationship between the effectiveness of SAA against neurovascular injury and its effects on calpain activation and endothelial nitric oxide synthase (eNOS) uncoupling.. SAA or vehicle was given to C57BL/6 male mice for seven days before the occlusion of middle cerebral artery (MCAO) for 60min.. High-resolution positron emission tomography scanner (micro-PET) was used for small animal imaging to examine glucose metabolism. Rota-rod time and neurological deficit scores were calculated after 24h of reperfusion. The volume of infarction was determined by Nissl-staining. The calpain proteolytic activity and eNOS uncoupling were determined by western blot analysis.. SAA administration increased glucose metabolism and ameliorated neuronal damage after brain ischemia, paralleled with decreased neurological deficit and volume of infarction. In addition, SAA pretreatment inhibited eNOS uncoupling and calpain proteolytic activity. Furthermore, SAA inhibited peroxynitrite (ONOO

Topics: Animals; Brain; Brain Ischemia; Caffeic Acids; Calpain; Drugs, Chinese Herbal; Infarction, Middle Cerebral Artery; Lactates; Male; Mice, Inbred C57BL; Neuroprotective Agents; Nitric Oxide Synthase Type III; Phosphorylation; Phytotherapy; Reperfusion Injury; Salvia miltiorrhiza; Up-Regulation

The aim of present study is to investigate the protective effects and mechanism of salvianolic acid A (SAA) on cerebral ischemia-reperfusion injury in rats. The model was established with middle cerebral artery occlusion and reperfusion (MCAO/R) with ischemia for 1.5 h and reperfusion for 24 h in adult male SD rats. After the behavior assessment, TTC assay was used to calculate the infarct volume of rat brain; the distribution of Nrf2 in nuclear and cytoplasm and expression of HO-1 were detected by Western blot. The PC12 cells injury model was established with oxygen-glucose deprivation for 6 h and reintroduction for 24 h. Cell viability was determined with MTT assay, and the expression of Nrf2 and HO-1 were detected through immunofluorescence staining. The mechanisms were investigated in PC12 cells with Nrf2 knocking down by siRNA. SAA (10 and 20 mg·kg(-1)) significantly reduced the neuronal damage in MCAO/R model, and SAA(0.5 and 5 μmol·L(-1)) increased cell viability in PC12 cells injury model. Meanwhile, the nuclear translocation of Nrf-2 and the expression of HO-1 were increased in PC12 cell and rats brain. SAA exhibited anti-cerebral ischemia- reperfusion effects. The mechanism may be related to activation of Nrf2/HO-1 signaling pathway, which promotes the synthesis and nuclear translocation of Nrf2 to enhance the expression of the antioxidant protein HO-1.

Topics: Animals; Brain; Brain Ischemia; Caffeic Acids; Heme Oxygenase (Decyclizing); Infarction, Middle Cerebral Artery; Lactates; Male; Neuroprotective Agents; NF-E2-Related Factor 2; Oxidative Stress; PC12 Cells; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction

This study investigated the neuroprotective effect of salvianolic acids (SA) against ischemia/reperfusion (I/R) injury, and explored whether the neuroprotection was dependent on mitochondrial connexin43 (mtCx43) via the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathway. In vitro, we measured astrocyte apoptosis, mitochondrial membrane potential, and also evaluated the morphology of astrocyte mitochondria with transmission electron microscopy. In vivo, we determined the cerebral infarction volume and measured superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. Additionally, mtCx43, p-mtCx43, AKT, and p-AKT levels were determined. In vitro, we found that I/R injury induced apoptosis, decreased cell mitochondrial membrane potential (MMP), and damaged mitochondrial morphology in astrocytes. In vivo, we found that I/R injury resulted in a large cerebral infarction, decreased SOD activity, and increased MDA expression. Additionally, I/R injury reduced both the p-mtCx43/mtCx43 and p-AKT/AKT ratios. We reported that both in vivo and in vitro, SA ameliorated the detrimental outcomes of the I/R. Interestingly, co-administering an inhibitor of the PI3K/AKT pathway blunted the effects of SA. SA represents a potential treatment option for cerebral infarction by up-regulating mtCx43 through the PI3K/AKT pathway.

Topics: Alkenes; Animals; Apoptosis; Astrocytes; Blotting, Western; Brain Ischemia; Infarction, Middle Cerebral Artery; Male; Membrane Potential, Mitochondrial; Mitochondria; Neuroprotective Agents; Polyphenols; Rats; Rats, Wistar; Reperfusion Injury; Signal Transduction

TSI is a new drug derived from Chinese medicine for treatment of ischemic stroke in China. The aim of this study was to verify the therapeutic effect of TSI in a rat model of MCAO, and further explore the mechanism for its effect.. Male Sprague-Dawley rats were subjected to right MCAO for 60 minutes followed by reperfusion. TSI (1.67 mg/kg) was administrated before reperfusion via femoral vein injection. Twenty-four hours after reperfusion, the fluorescence intensity of DHR 123 in, leukocyte adhesion to and albumin leakage from the cerebral venules were observed. Neurological scores, TTC staining, brain water content, Nissl staining, TUNEL staining, and MDA content were assessed. Bcl-2/Bax, cleaved caspase-3, NADPH oxidase subunits p47(phox)/p67(phox)/gp91(phox), and AMPK/Akt/PKC were analyzed by Western blot.. TSI attenuated I/R-induced microcirculatory disturbance and neuron damage, activated AMPK, inhibited NADPH oxidase subunits membrane translocation, suppressed Akt phosphorylation, and PKC translocation.. TSI attenuates I/R-induced brain injury in rats, supporting its clinic use for treatment of acute ischemic stroke. The role of TSI may benefit from its antioxidant activity, which is most likely implemented via inactivation of NADPH oxidase through a signaling pathway implicating AMPK/Akt/PKC.

Topics: Alkenes; AMP-Activated Protein Kinases; Animals; Apoptosis; Capillary Permeability; Cerebral Infarction; Drugs, Chinese Herbal; Infarction, Middle Cerebral Artery; Leukocytes; Lipid Peroxidation; Male; Microcirculation; Movement Disorders; NADPH Oxidases; Nerve Tissue Proteins; Neurons; Phosphorylation; Polyphenols; Protein Kinase C; Protein Transport; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction

Excitatory amino acid toxicity, oxidative stress, intracellular calcium overload, as well as inflammation and apoptosis are involved in the pathological process after cerebral ischemic reperfusion injury. Picrodide 2 could inhibit neuronal apoptosis and play anti-oxidant and anti-inflammation role in cerebral ischemia/reperfusion injuries, but the exact mechanism is not very clear. This study aims to explore the anti-inflammation mechanism of picroside 2 in cerebral ischemic reperfusion injury in rats.. The middle cerebral artery occlusion reperfusion models were established with intraluminal thread methods in 90 adult healthy female Wistar rats. Picroside 2 and salvianic acid A sodium were respectively injected from tail vein at the dosage of 10 mg/kg for treatment. The neurobehavioral function was evaluated with Bederson's test and the cerebral infarction volume was observed with tetrazolium chloride (TTC) staining. The apoptotic cells were counted by in situ terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphate nick end labeling (TUNEL) assay. The immunohistochemistry stain was used to determine the expressions of toll-like receptor 4 (TLR4), nuclear transcription factor kappaB (NFkappaB) and tumor necrosis factor alpha (TNFalpha). The concentrations of TLR4, NFkappaB and TNFalpha in brain tissue were determined by enzyme linked immunosorbent assay (ELISA).. After cerebral ischemic reperfusion, the rats showed neurobehavioral function deficit and cerebral infarction in the ischemic hemisphere. The number of apoptotic cells, the expressions and the concentrations in brain tissue of TLR4, NFkappaB and TNFalpha in ischemia control group increased significantly than those in the sham operative group (P < 0.01). Compared with the ischemia control group, the neurobehavioral scores, the infarction volumes, the apoptotic cells, the expressions and concentrations in brain tissue of TLR4, NFkappaB and TNFalpha were obviously decreased both in the picroside 2 and salvianic acid A sodium groups (P < 0.01). There was no statistical difference between the two treatment groups in above indexes (P > 0.05).. Picroside 2 could down-regulate the expressions of TLR4, NFkappaB and TNFalpha to inhibit apoptosis and inflammation induced by cerebral ischemic reperfusion injury and improve the neurobehavioral function of rats.

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Brain; Brain Ischemia; Caffeic Acids; Cinnamates; Disease Models, Animal; Encephalitis; Female; Glucosides; Infarction, Middle Cerebral Artery; Iridoid Glucosides; Lactates; Neuropsychological Tests; NF-kappa B; Random Allocation; Rats; Rats, Wistar; Reperfusion Injury; Toll-Like Receptor 4; Treatment Outcome; Tumor Necrosis Factor-alpha