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

Ischemic stroke is the second leading cause of death and the third leading cause of disability worldwide. Salvianolic acid B (SAB), a water-soluble phenolic acid derived from the traditional Chinese medicine Salvia miltiorrhiza, exerted protective effects on cerebral ischemia-reperfusion injury. However, the efficacy of SAB is seriously hindered by poor blood brain barrier (BBB) permeability and short biological half-life in plasma. Brain targeted biomimetic nanoparticle delivery systems offer much promise in overcoming these limitations.. A brain targeted biomimetic nanomedicine (RR@SABNPs) was developed, which comprised of SAB loaded bovine serum albumin nanoparticles and functionalized red blood cell membrane (RBCM) with Arg-Gly-Asp (RGD). The characterization parameters, including particle size, zeta potential, morphology, Encapsulation Efficiency (EE), Drug Loading (DL), release behavior, stability, and biocompatibility, were investigated. Moreover, the middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was used to assess the therapeutic efficacy of RR@SABNPs on ischemic stroke. Finally, the reactive oxygen species (ROS) levels and mitochondrial membrane potential (MMP) were detected by DHE and JC‑1 staining in oxygen-glucose deprivation/reperfusion (OGD/R) and H. RR@SABNPs exhibited spheric morphology with core-shell structures and good stability and biocompatibility. Meanwhile, RR@SABNPs can significantly prolong SAB circulation time by overcoming the reticuloendothelial system (RES) and actively targeting ischemic BBB. Moreover, RR@SABNPs had comprehensive protective effects on MCAO/R model mice, manifested as a reduced infarct volume and improved neurological and sensorimotor functions, and significantly scavenged excess ROS and maintained MMP.. The designed brain targeted biomimetic nanomedicine RR@SABNPs can significantly prolong the half-time of SAB, deliver SAB into the ischemic brain and exhibit good therapeutic effects on MCAO/R model mice.

Topics: Animals; Benzofurans; Brain Ischemia; Erythrocyte Membrane; Hydrogen Peroxide; Infarction, Middle Cerebral Artery; Ischemic Stroke; Mice; Nanoparticles; Rats; Reactive Oxygen Species; Reperfusion Injury

The purpose of this study was to evaluate the cerebral protection of salvianolic acid B (Sal B) against cerebral I/R injury and investigate the underlying mechanism. As shown by 2,3,5-Triphenyltetrazolium chloride (TTC) staining and magnetic resonance imaging (MRI) analyses, Sal B significantly reduced cerebral infarct size, and accompanied with improved neurobehavioral functions as indicated by the modified Bederson score and Longa five-point scale. Sal B decreased the production of reactive oxygen species (p < .05, n = 10). The data of Western blotting and reverse transcription quantitative real time polymerase chain reaction (qRT-PCR) analyses showed that the expression of GFAP, Iba1, IL-1β, IL-6, TNF-α and Cleaved-caspase 3 was significantly reduced by Sal B in I/R injured brain tissues as compared to corresponding controls (p < .05, n = 10). Over activation of astrocytes and microglia were inhibited by Sal B as shown by immunostaining of GFAP and Iba 1. These data suggest that Sal B has neural protective effects against I/R-induced cerebral injury and could be an effective candidate for further development of clinical therapy.

Topics: Animals; Benzofurans; Brain Injuries; Calcium-Binding Proteins; Caspase 3; Cerebral Infarction; Cytokines; Disease Models, Animal; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Infarction, Middle Cerebral Artery; Male; Mice; Mice, Inbred C57BL; Microfilament Proteins; Neuroprotective Agents; Reperfusion

Neuroinflammation plays a critical role in the pathogenesis of ischemia/reperfusion (I/R) injury. Activated platelets are increasingly regarded as initiators and/or amplifiers of inflammatory processes in cerebral I/R injury. Salvianolic acid B (SAB) is the most abundant bioactive compound of Salviae miltiorrhizae, a well-known Chinese herb used to promote blood circulation and eliminating blood stasis. S. miltiorrhizae has been used clinically in Asia for the treatment of ischemic cerebrovascular diseases. In the present study, a rat model of transient middle cerebral artery occlusion (tMCAO) was established to investigate the neuroprotective effects and mechanisms of SAB treatment against focal cerebral I/R insult. The results showed that SAB treatment (3mg/kg, 6mg/kg and 12mg/kg, i.p.) dose-dependently decreased I/R-induced neurological deficits at 24, 48, and 72h after reperfusion and decreased plasma-soluble P-selectin and soluble CD40 ligand as early as 6h after onset of I/R insult. At 24h after reperfusion, SAB treatment significantly reduced neuronal and DNA damage in the hippocampal CA1 region and decreased neural cell loss in the ischemic core. The I/R-induced pro-inflammatory mediator mRNA and protein overexpression in the penumbra cortex, including ICAM-1, IL-1β, IL-6, IL-8, and MCP-1, were significantly inhibited by SAB in a dose-dependent manner. Further studies suggested SAB treatment attenuated CD40 expression and NF-κB activation, which involved NF-κB/p65 phosphorylation and IκBα phosphorylation and degradation. In conclusion, our findings indicated that the neuroprotective effects of SAB post cerebral I/R injury are associated with the inhibition of both platelets activation and production of pro-inflammatory mediators and the downregulation of the CD40/NF-κB pathway.

Topics: Animals; Benzofurans; Blood Platelets; Brain Ischemia; CA1 Region, Hippocampal; CD40 Antigens; Dose-Response Relationship, Drug; Infarction, Middle Cerebral Artery; Inflammation; Male; Neuroimmunomodulation; Neuroprotective Agents; NF-kappa B; Platelet Activation; Rats; Rats, Wistar; Reperfusion; Reperfusion Injury; Signal Transduction; Transcription Factor RelA

Ischemic stroke can activate multiple transcription factors and cause inflammatory reactions, which involve pattern recognition receptors with immunostimulatory effects. Toll-like receptor 4 (TLR4) is one of the receptors related to innate immunity and several inflammatory reactions. The promising anti- inflammatory activity of salvianolic acid B (SAB) had been previously reported, but its effect on ischemic stroke remains unknown. An oxygen-glucose deprivation and reoxygenation (OGD/R) model in vitro and a middle cerebral artery occlusion (MCAO) model in vivo were used in this paper, and the results showned that SAB remarkably increased the viabilities of PC12 cells and primary cortical neurons after OGD/R injury and notably prevented cerebral ischemia/reperfusion (I/R) injury. SAB also significantly ameliorated NeuN release from primary cortical neurons. Further research indicated that the neuroprotection of SAB was completed through inhibiting the TLR4/MyD88/TRAF6 signaling pathway. The blocking of TLR4 by SAB also restrained NF-kB transcriptional activity and pro-inflammatory cytokine responses (IL-1β, IL-6, and TNF-α). These findings supply a new insight that will aid in clarifying the effect of SAB against cerebral I/R injury and provide the development of SAB as a potential candidate for treating ischemic stroke.

Topics: Animals; Anti-Inflammatory Agents; Benzofurans; Brain Ischemia; Cells, Cultured; Cytokines; Disease Models, Animal; Infarction, Middle Cerebral Artery; Myeloid Differentiation Factor 88; Neurons; Neuroprotective Agents; PC12 Cells; Rats; Reperfusion Injury; Signal Transduction; TNF Receptor-Associated Factor 6; Toll-Like Receptor 4

Silent information regulator 1 (SIRT1), a histone deacetylase, has been suggested to be effective in ischemic brain diseases. Salvianolic acid B (SalB) is a polyphenolic and one of the active components of Salvia miltiorrhiza Bunge. Previous studies suggested that SalB is protective against ischemic stroke. However, the role of SIRT1 in the protective effect of SalB against cerebral ischemia has not been explored. In this study, the rat brain was subjected to middle cerebral artery occlusion (MCAO). Before this surgery, rats were intraperitoneally administrated SalB with or without EX527, a specific SIRT1 inhibitor. The infarct volume, neurological score and brain water content were assessed. In addition, levels of TNF-α and IL-1β in the brain tissues were detected by commercial ELISA kits. And the expression levels of SIRT, Ac-FOXO1, Bcl-2 and Bax were detected by Western blot. The results suggested that SalB exerted a cerebral-protective effect, as shown by reduced infarct volume, lowered brain edema and increased neurological scores. SalB also exerted anti-inflammatory effects as indicated by the decreased TNF-α and IL-1β levels in the brain tissue. Moreover, SalB upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of Ac-FOXO1 and Bax. These effects of SalB were abolished by EX527 treatment. In summary, our results demonstrate that SalB treatment attenuates brain injury induced by ischemic stoke via reducing apoptosis and inflammation through the activation of SIRT1 signaling.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Benzofurans; Brain; Brain Edema; Brain Ischemia; Carbazoles; Central Nervous System Agents; Disease Models, Animal; Infarction, Middle Cerebral Artery; Inflammation; Male; Neuroprotective Agents; Random Allocation; Rats, Sprague-Dawley; Severity of Illness Index; Sirtuin 1; Stroke; Treatment Outcome

SMND-309 is a novel derivative of salvianolic acid B, and has shown protective effects against rat cortical neuron damage in vitro and in vivo. However the molecular mechanisms through which SMND-309 affords this protection are unclear. The present study aimed to investigate the mechanisms associated with the protective activities of SMND-309 in a cerebral ischemia and reperfusion injury rat model. In this study, we used AG490, a specific inhibitor of the signaling pathway involving the Janus Kinase 2 (JAK2)/Signal Transducers and Activators of Transcription 3 (STAT3) signaling molecules and suramin, a potent inhibitor of vascular endothelial growth factor (VEGF), to investigate the mechanisms of SMND-309. The cerebral ischemia and reperfusion injury model was induced by performing middle cerebral artery occlusion (MCAO) in the rats. SMND-309 mitigated the effects of ischemia and reperfusion injury on brain by decreasing the infract volume, improving neurological function, increasing the survival of neurons and promoting angiogenesis by increasing the levels of erythropoietin (EPO), erythropoietin receptor (EPOR), phosphorylated JAK2 (P-JAK2), phosphorylated STAT3 (P-STAT3), VEGF and VEGF receptor 2 (Flk-1) in the brain. Our results suggest that SMND-309 provides significant neuroprotective effects against cerebral ischemia and reperfusion injury. The mechanisms of this protection may be attributed to the increased VEGF expression occurring from the JAK2/STAT3 pathway, activated by the increased EPO/EPOR expression in the brain.

Topics: Animals; Axons; Benzofurans; Brain; Brain Ischemia; Caffeic Acids; Cerebral Infarction; Dendrites; Erythropoietin; Gene Expression Regulation; Infarction, Middle Cerebral Artery; Janus Kinase 2; Male; Neovascularization, Physiologic; Neuroprotective Agents; Phosphoproteins; Platelet Endothelial Cell Adhesion Molecule-1; Rats; Rats, Sprague-Dawley; Receptors, Erythropoietin; Recovery of Function; Reperfusion Injury; Signal Transduction; STAT3 Transcription Factor; Survival Analysis; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2; Water

The aim of the study is to investigate the effect of salvianolic acid B (SalB) on blood-brain barrier (BBB) in rats after cerebral ischemia-reperfusion, and to illustrate its possible mechanisms. Cerebral ischemia-reperfusion was induced by middle cerebral artery occlusion in rats. The break-down of BBB was indicated by extravasations of immunoglobulin (IgG) monitored with immunohistochemistry. The expression of MMP-9 and NOS2 in the brain was determined by immunohistochemistry, and the expression of p-p38 and p-ERK1/2 was detected by Western blotting. It was shown that on day 2 after ischemia-reperfusion the IgG accumulated around the vascular boundary zone, suggesting the break-down of BBB, and the expression of MMP-9 and NOS2 up-regulated at the same time. The result of Western blotting suggested that the expression of p-p38 and p-ERK1/2 increased. On day 7 after ischemia-reperfusion the. expression of MMP-9 and NOS2 was about the same level as day 2, the expression of p-p38 was higher than that on day 2 and the expression of p-ERK1/2 was slightly lower than that on day 2. SalB (1 and 10 mg x kg(-1)) significantly alleviated the extravasations of immunoglobulin induced by cerebral ischemia-reperfusion (P < 0.05). On day 2 and day 7 SalB attenuated the expression of MMP-9 and NOS2 (P < 0.05). SalB (10 mg x kg(-1)) reduced the expression of p-p38 and p-ERK1/2 apparently on day 2 and 7 after ischemia-reperfusion (P < 0.05). SalB (1 mg x kg(-1)) inhibited the expression of p-p38 on day 7 after ischemia-reperfusion (P < 0.05). The results indicate that SalB protects blood-brain barrier in rats after cerebral ischemia-reperfusion by inhibiting the MAPK pathway.

Topics: Animals; Benzofurans; Blood-Brain Barrier; Brain Ischemia; Drugs, Chinese Herbal; Infarction, Middle Cerebral Artery; Male; MAP Kinase Kinase Kinase 1; MAP Kinase Signaling System; Matrix Metalloproteinase 9; Nitric Oxide Synthase Type II; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Plants, Medicinal; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Salvia miltiorrhiza

This study is to observe the effect of salvianolic acid B (Sal B) on neural cells damage and neurogenesis in sub-granular zone (SGZ) and sub-ventricular zone (SVZ) after brain ischemia-reperfusion (I/R) in rats. A modified middle cerebral artery occlusion (MCAO) model of focal cerebral ischemia-reperfusion was used. The rats were divided into four groups: sham control group, ischemia-reperfusion group, Sal B 1 and 10 mg x kg(-1) groups. Sal B was consecutively administrated once a day by ip injection after MCAO. The neurogenesis in SGZ and SVZ was investigated by BrdU method 7 days after MCAO. The Nissl staining for neurons in the hippocampal CA1 and cerebral cortex was performed 14 days after MCAO. A beam-walking test was used to monitor the motor function recovery. We found that brain ischemia resulted in an increase of BrdU positive cells both in ipsilateral SGZ and SVZ at 7th day after MCAO. Sal B (10 mg x kg(-1)) significantly increased further the number of BrdU positive cells both in SGZ and SVZ (P < 0.01). Ipsilateral hippocampal neuron damage occurred and CA1 almost lost 14 days after MCAO. Sal B (10 mg x kg(-1)) obviously attenuated the neuron damage and increased the number of neuron both in ipsilateral CA1 and cerebral cortex (P < 0.01). We also observed an obvious improvement of motor function recovery when Sal B (10 mg x kg(-1)) administrated. From the results above we concluded that Sal B stimulated neurogenesis process both in SGZ and SVZ after brain ischemia, and also alleviated neural cells loss and improved motor function recovery after brain ischemia in rats.

Topics: Animals; Benzofurans; Cell Count; Cerebral Cortex; Cerebral Ventricles; Dentate Gyrus; Hippocampus; Infarction, Middle Cerebral Artery; Male; Motor Activity; Neurogenesis; Neurons; Plants, Medicinal; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Salvia miltiorrhiza

In a previous short-term study, salvianolic acid B was reported to have a protective effect on cerebral ischemia. Here, we investigated whether salvianolic acid B improves the recovery of motor function after cerebral ischemia in a 14-day investigation. Cerebral ischemia was induced by middle cerebral artery occlusion in rats. Motor function was evaluated with beam-walking performance. Neural cell injury in both the sensorimotor cortex and CA1 of the hippocampus ipsilateral to ischemia was studied by Nissl stain with methylene blue. The integrity of cerebral microvessels was monitored by immunoglobulin extravasations. Neurogenesis in the subgranular zone in the dentate gyrus of the hippocampus was detected with 5'-bromo-2'-deoxyuridine incorporation. Animals receiving salvianolic acid B at a dose of 10 mg/kg had a more rapid recovery of beam-walking performance than vehicle-treated ischemia animals, and the improvement became significant at 10 and 14 days after ischemia (P<0.05). Treatment with salvianolic acid B at a dose of 10 mg/kg also significantly prevented neural cell loss in CA1 of the hippocampus. Neural cells in the sensorimotor cortex were also preserved in animals that received salvianolic acid B at a high dose of 10 mg/kg. Salvianolic acid B (10 mg/kg) also improved the integrity of microvessels after ischemia. We observed a slight increase in 5'-bromo-2'-deoxyuridine-positive cells in the subgranular zone of the hippocampus in the animals treated with salvianolic acid B at a dose of 10 mg/kg. These data indicate that salvianolic acid B could improve the recovery of motor function after cerebral ischemia in rats.

Topics: Animals; Benzofurans; Cell Survival; Hippocampus; Infarction, Middle Cerebral Artery; Male; Microcirculation; Motor Activity; Motor Skills; Nerve Regeneration; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Somatosensory Cortex