Salvianolic acid B promotes survival of transplanted mesenchymal stem cells in spinal cord-injured rats

Salvianolic acid B combined with bone marrow mesenchymal stem cells piggybacked on HAMA hydrogel re-transplantation improves intervertebral disc degeneration

Cell-based tissue engineering approaches have emerged as a realistic alternative for regenerative disc tissue repair. The multidirectional differentiation potential of bone marrow mesenchymal stem cells (BMSCs) to treat disc degeneration intervertebral disc degeneration has also become a viable option. We used 1% HAMA hydrogel as a carrier and co-encapsulated BMSCs and Salvianolic acid B (SalB) into the hydrogel to reduce the apoptosis of the transplanted cells. The protective effect of SalB on BMSCs was first verified in vitro using the CCK8 method, flow cytometry, and Western-Blotting, and the physical properties and biocompatibility of HAMA hydrogels were verified in vitro. The rat model was then established using the pinprick method and taken at 4 and 8 W, to examine the extent of disc degeneration by histology and immunohistochemistry, respectively. It was found that SalB could effectively reduce the apoptosis of BMSCs in vitro by activating the JAK2-STAT3 pathway. 1% HAMA hydrogels had larger pore size and better water retention, and the percentage of cell survival within the hydrogels was significantly higher after the addition of SalB to the HAMA hydrogels. In the in vivo setting, the HAMA + SalB + BMSCs group had a more pronounced delaying effect on the progression of disc degeneration compared to the other treatment groups. The method used in this study to encapsulate protective drugs with stem cells in a hydrogel for injection into the lesion has potential research value in the field of regenerative medicine.

Salvianolic acid B combined with mesenchymal stem cells contributes to nucleus pulposus regeneration

PURPOSE

To investigate whether salvianolic acid B is able to enhance repair of degenerated intervertebral discs by mesenchymal stem cells (MSCs) through the promotion of MSC differentiation into nucleus pulposus cells in a nucleus-pulposus-like environment and by enhancing the trophic effect of MSCs on residual nucleus pulposus cells (mediated by transforming growth factor-β1).

MATERIALS AND METHODS

Successful intervertebral disc degeneration models, established by aspiration of the nucleus pulposus in New Zealand white rabbits, were randomly divided into eight groups: Group A was treated with MSC transplantation. Group B was treated with MSC transplantation and salvianolic acid B, with the subgroups B1, B2, B3, and B4 receiving 0.01 mg/L, 0.1 mg/L, 1 mg/L, and 10 mg/L salvianolic acid B, respectively. Groups C and D were treated with phosphate buffer saline and sham graft, respectively. Group E was the normal control group. At the end of week 8, the type II collagen, proteoglycan, transforming growth factor-β1, and water contents in each group were examined by semi-quantitative immunohistochemistry, spectrophotometry, enzyme-linked immunosorbent assay, and magnetic resonance, respectively.

RESULTS

The content of type II collagen, proteoglycan, transforming growth factor-β1, and water in groups B3 and B4 were significantly higher than those in group A (p < 0.01).

CONCLUSIONS

Salvianolic acid B (1 mg/L to 10 mg/L) plus MSC transplantation was more effective in repairing degenerated intervertebral discs than was stem cell transplantation alone.

Salvianolic acid B activates Wnt/β-catenin signaling following spinal cord injury

Neural cell apoptosis serves a key role in spinal cord injury (SCI), which is a threat to human health. The present study aimed to evaluate the neuroprotective mechanism of salvianolic acid B (Sal B) in a spinal cord injury (SCI) rat model. Basso, Beattie, and Bresnahan scores demonstrated that Sal B treatment significantly increased locomotor functional recovery in SCI rats compared with SCI model rats between 3 and 8 weeks. Nissl staining demonstrated that Sal B enhanced motor neuron survival and decreased lesion size after SCI. Reverse transcription-quantitative PCR analysis demonstrated that Sal B treatment significantly enhanced the mRNA levels of lymphoid enhancer biding factor-1 and HNF1 homeobox A. In addition, Sal B treatment enhanced the expression of β-catenin. Western blot analysis determined that Sal B treatment significantly decreased the expression of pro-apoptosis proteins, including Bax, cleaved caspase-3 and -9, in spinal cord tissues after SCI but enhanced the expression of Bcl-2, an anti-apoptotic protein. Furthermore, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining demonstrated that, compared with the SCI group, Sal B treatment decreased the number of TUNEL-positive neurons. In summary, the present study produced novel data demonstrating the neuroprotective effect of Sal B on SCI with the mechanism likely primarily mediated via the Wnt/β-catenin signaling pathway. The present findings may be of potential therapeutic value for future SCI treatments.

Danshen extract (Salvia miltiorrhiza Bunge) attenuate spinal cord injury in a rat model: A metabolomic approach for the mechanism study

BACKGROUD

Spinal cord injury (SCI) is a devastating neurological disorder caused by trauma. To date, SCI treatment is still a significant challenge in clinic and research around the world. Danshen (dried roots and rhizomes of Salvia miltiorrhiza), a commonly used Chinese medicinal herb, has been attracting attention in SCI treatment.

PURPOSE

Aim of this study was to evaluate the potential beneficial effects of danshen extract in a SCI rat model, as well as investigate possible mechanism of action and potential biomarkers.

METHODS

Here, a rat SCI model was established with weight-drop method, and danshen extract was administered by oral gavage (12.5 g/kg). Recovery of motor function and histomorphological changes were evaluated by Basso, Beattie and Bresnahan score and hematoxylin-eosin staining, respectively. In addition, neurofilament 200 (NF-H), brain-derived neurotrophic factor (BDNF), glial fibrillary acidic protein (GFAP) and CD11b expressions were assayed by immunofluorescence and western blot analysis. Furthermore, a metabolomics analysis based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach was conducted.

RESULTS

The results demonstrated that danshen extract could significantly ameliorated histopathology changes and improved recovery of motor function after SCI. Moreover, NF-H, BDNF and CD11b expression were progressively increased until 4 weeks post-injury after administrated danshen extract. Furthermore, a good separation was observed among different groups using OPLS-DA. Trajectory analysis showed the gradual shift from position of model group toward normal group with increasing time after administration of danshen extract. Meanwhile, 51 significantly altered metabolites were identified, while metabolic pathway analysis suggested that 6 metabolic pathways were disturbed by the altered metabolites.

CONCLUSION

In summary, this study provides an overview of neuroprotective effects and investigates possible mechanism of danshen extract in SCI treatment. However, further research is needed to uncover its regulatory mechanisms more clearly.

Salvia miltiorrhiza enhances the survival of mesenchymal stem cells under ischemic conditions

Objectives

To validate the enhanced therapeutic effect of Salvia miltiorrhiza Bunge (SM) for brain ischemic stroke through the anti‐apoptotic and survival ability of mesenchymal stem cells (MSCs).

Methods

The viability and the expression level of cell apoptotic and survival‐related proteins in MSCs by treatment of SM were assessed in vitro. In addition, the infarcted brain region and the behavioural changes after treatment of MSCs with SM were confirmed in rat middle cerebral artery occlusion (MCAo) models.

Key findings

We demonstrated that SM attenuates apoptosis and improves the cell viability of MSCs. In the rat MCAo model, the recovery of the infarcted region and positive changes of behaviour are observed after treatment of MSCs with SM.

Conclusions

The therapy using SM enhances the therapeutic effect for brain ischemic stroke by promoting the survival of MSCs. This synergetic effect thereby proposes a new experimental approach of traditional Chinese medicine and stem cell‐based therapies for patients suffering from a variety of diseases.

Salvia miltiorrhiza: A source for anti-Alzheimer's disease drugs

CONTEXT

Alzheimer's disease (AD) is a devastating neurodegenerative disorder that affects millions of elderly people worldwide. However, no efficient therapeutic method for AD has yet been developed. Recently, Salvia miltiorrhiza Bunge (Lamiaceae), a well-known traditional Chinese medicine which is widely used for treating cardio-cerebrovascular, exerts multiple neuroprotective effects and is attracting increased attention for the treatment of AD.

OBJECTIVE

The objective of this study is to discuss the neuroprotective effects and neurogenesis-inducing activities of S. miltiorrhiza components.

METHODS

A detailed search using major electronic search engines (such as Pubmed, ScienceDirect, and Google Scholar) was undertaken with the search terms: Salvia miltiorrhiza, the components of S. miltiorrhiza such as salvianolic acid B, salvianolic acid A, danshensu, tanshinone I, tanshinone IIA, cryptotanshinone, dihydrotanshinone, and neuroprotection.

RESULTS

Salvia miltiorrhiza components exert multiple neuroprotective potentials relevant to AD, such as anti-amyloid-β, antioxidant, anti-apoptosis, acetylcholinesterase inhibition, and anti-inflammation. Moreover, S. miltiorrhiza promotes neurogenesis of neural progenitor cells/stem cells in vitro and in vivo.

CONCLUSIONS

The properties of S. miltiorrhiza indicate their therapeutic potential in AD via multiple mechanisms. In addition, S. miltiorrhiza provides lead compounds for developing new drugs against AD.

Protective Effects and Mechanisms of Salvianolic Acid B Against H₂O₂-Induced Injury in Induced Pluripotent Stem Cell-Derived Neural Stem Cells

Induced pluripotent stem cells (iPSCs) have the potential to differentiate into neural lineages. Salvianolic acid B (Sal B) is a commonly used, traditional Chinese medicine for enhancing neuroprotective effects, and has antioxidant, anti-inflammatory, and antiapoptotic properties. Here, we explore the potential mechanism of Sal B in protecting iPSC-derived neural stem cells (NSCs) against H2O2-induced injury. iPSCs were induced into NSCs, iPSC-derived NSCs were treated with 50 μM Sal B for 24.5 h and 500 μM H2O2 for 24 h. The resulting effects were examined by flow cytometry analysis, quantitative reverse-transcription polymerase chain reaction, and western blotting. Upon H2O2 exposure, Sal B significantly promoted cell viability and stabilization of the mitochondrial membrane potential. Sal B also visibly decreased the cell apoptotic ratio. In addition, Sal B markedly reduced expression of matrix metalloproteinase (MMP)-2 and -9, and phosphospecific signal transducer and activator of transcription 3 (p-STAT3), and increased the level of tissue inhibitor of metalloproteinase (TIMP)-2 in iPSC-derived NSCs induced by H2O2. These results suggest that Sal B protects iPSC-derived NSCs against H2O2-induced oxidative stress. The mechanisms of this stress tolerance may be attributed to modulation of the MMP/TIMP system and inhibition of the STAT3 signaling pathway.

Effects of mesenchymal stem cell therapy, in association with pharmacologically active microcarriers releasing VEGF, in an ischaemic stroke model in the rat

Few effective therapeutic interventions are available to limit brain damage and functional deficits after ischaemic stroke. Within this context, mesenchymal stem cell (MSC) therapy carries minimal risks while remaining efficacious through the secretion of trophic, protective, neurogenic and angiogenic factors. The limited survival rate of MSCs restricts their beneficial effects. The usefulness of a three-dimensional support, such as a pharmacologically active microcarrier (PAM), on the survival of MSCs during hypoxia has been shown in vitro, especially when the PAMs were loaded with vascular endothelial growth factor (VEGF). In the present study, the effect of MSCs attached to laminin-PAMs (LM-PAMs), releasing VEGF or not, was evaluated in vivo in a model of transient stroke. The parameters assessed were infarct volume, functional recovery and endogenous cellular reactions. LM-PAMs induced the expression of neuronal markers by MSCs both in vitro and in vivo. Moreover, the prolonged release of VEGF increased angiogenesis around the site of implantation of the LM-PAMs and facilitated the migration of immature neurons towards the ischaemic tissue. Nonetheless, MSCs/LM-PAMs-VEGF failed to improve sensorimotor functions. The use of LM-PAMs to convey MSCs and to deliver growth factors could be an effective strategy to repair the brain damage caused by a stroke.

Immunosuppression of allogenic mesenchymal stem cells transplantation after spinal cord injury improves graft survival and beneficial outcomes

Cell therapy for spinal cord injury (SCI) is a promising strategy for clinical application. Mesenchymal stem cells (MSC) have demonstrated beneficial effects following transplantation in animal models of SCI. However, despite the immunoprivilege properties of the MSC, their survival in the injured spinal cord is reduced due to the detrimental milieu in the damaged tissue and immune rejection of the cells. The limited survival of the engrafted cells may determine the therapy success. Therefore, we compared two strategies to increase the presence of the cells in the injured spinal cord in rats: increasing the amount of MSC transplants and using immunosuppressive treatment with FK506 after transplantation. Functional outcomes for locomotion and electrophysiological responses were assessed. The grafted cells survival and the amount of cavity and spared tissue were studied. The findings indicate that immunosuppression improved grafted cells survival. A cell-dose effect was found regarding locomotion recovery and tissue protection independent of immunosuppression. Nevertheless, immunosuppression enhanced the electrophysiological outcomes and allowed filling of the cavity formed after injury by new regenerative tissue and axons. These results indicate that MSC transplantation combined with immunosuppression prolongs the survival of engrafted cells and improves functional and morphological outcomes after SCI.

Osthole augments therapeutic efficiency of neural stem cells-based therapy in experimental autoimmune encephalomyelitis

The therapeutic potential of adult neural stem cells (NSCs)-derived from bone marrow (BM) has been recently described in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis; however, the beneficial effects are modest due to their marginal anti-inflammatory capacity. To overcome this weakness and endow BM-NSC therapy with profound anti-inflammatory capacity, in this study we pretreated EAE mice with osthole, a natural coumarin with a broad spectrum of pharmacological activities, including anti-inflammation, immunomodulation, and neuroprotection, before NSC-application and continued throughout the study. We found that osthole conferred a potent anti-inflammatory capacity to this BM-NSC therapy, thus more profoundly suppressing ongoing EA and exhibiting significant advantages over conventional NSC-therapy as follows: 1) Enhanced anti-inflammatory effect, thus improving survival environment for engrafted BM-NSCs and protecting myelin sheaths from further demyelination; 2)Drove transplanted (exogenous) BM-NSCs to differentiate into more oligodendrocytes and neurons but inhibited differentiation into astrocytes, thus promoting remyelination and axonal growth, and reducing astrogliosis; and 3) augmented CNS neurotrophic support thus promoted resident (endogenous) repair of myelin/axonal damage. These effects make the BM-NSCs-based therapy a more promising approach to enhance remyelination and neuronal repopulation, thus more effectively promoting anatomic and functional recovery from neurological deficits.

Effects of Salvia miltiorrhiza on neural differentiation of induced pluripotent stem cells

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza, a well-known traditional Chinese medicine, is commonly used to treat some neurological diseases because of its anti-oxidative, anti-inflammatory and anti-apoptotic properties. We investigate whether Salvia miltiorrhiza can improve the differentiation of induced pluripotent stem cells (iPSCs) into neurons in vitro, and promote iPSCs-derived neural stem cells survival, integrate, and differentiation after their transplantation to the ischemic brain tissues.

MATERIALS AND METHODS

Induced pluripotent stem cells were used to differentiate into neural stem cells, and further into neurons in induction medium with various concentrations of Salvia miltiorrhiza. The effects were assessed by immunofluorescence staining, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. iPSC-derived neural stem cells were transplanted into the brains of rats with middle cerebral artery occlusion, immunofluorescence staining was used to evaluate survival, integrate, and differentiation of grafted cells, the functional recovery of the animals was tested by the Longa scores and spontaneous motor activity.

RESULTS

Salvia miltiorrhiza (5μg/ml) significantly increased the gene and protein expression of Nestin compared with that in other groups. Microtubule-associated protein 2 (MAP2) expression in induction medium with 5μg/ml Salvia miltiorrhiza was significantly higher than that in the control group. After cells transplantation into the ischemic brain, more grafted MAP2(+) cells were found in Salvia miltiorrhiza-treated rats than others at 7 days. Salvia miltiorrhiza-treated rats showed the most remarkable functional recovery at 7 and 14 days.

CONCLUSION

Salvia miltiorrhiza induces differentiation of induced pluripotent stem cells to differentiate into neurons efficiently. The plant provides neuroprotection to implanted cells and improves functional recovery after their transplantation to the ischemic brain tissues.

Effects of salvianolic acid B on survival, self-renewal and neuronal differentiation of bone marrow derived neural stem cells

Our previous study has demonstrated the therapeutic potential of bone marrow derived-neural stem cells (BM-NSCs) in CNS disorders; however, the beneficial effects are modest due to the poor survival and low neural differentiation frequency. Here, we demonstrate that salvianolic acid B (Sal B), a potent aqueous of a well known Chinese medicine herb, Salvia miltiorrhiza, possesses the ability to promote BM-NSCs proliferation in a dose dependent manner as verified by growth curve and Bromodeoxyuridine (BrdU) incorporation assays; While in differentiation medium, Sal B promoted nestin(+) BM-NSCs differentiated into greater numbers of NF-M(+) neurons and NG2(+) oligodendrocyte precursors, but fewer GFAP(+) astrocytes as verified by triple immunostaining and quantitative analysis; upon exposure to H(2)O(2), Sal B facilitated the cells survival, reduced LDH leakage, and inhibited apoptosis, displaying a dose-dependent neuroprotective effect on BM-NSCs. Sal B induced brain-derived neurotrophic factor (BDNF) production by BM-NSCs, which may be beneficial for the cells survival and differentiation in unfavourable environment. The collective evidence indicates that Sal B may be a potential drug to upgrade the therapeutic efficiency of BM-NSCs in CNS diseases.

Evaluation of cell tracking effects for transplanted mesenchymal stem cells with jetPEI/Gd-DTPA complexes in animal models of hemorrhagic spinal cord injury

Cell tracking using iron oxide nanoparticles has been well established in MRI. However, in experimental rat models, the intrinsic iron signal derived from erythrocytes masks the labeled cells. The research evaluated a clinically applied Gd-DTPA for T1-weighted positive enhancement for cell tracking in spinal cord injury (SCI) rat models. MSCs were labeled with jetPEI/Gd-DTPA particles to evaluate the transfection efficiency by MRI in vitro. Differentiation assays were carried out to evaluate the differentiation ability of Gd-DTPA-labeled MSCs. The Gd-DTPA-labeled MSCs were transplanted to rat SCI model and monitored by MRI in vivo. Fluorescence images were taken to confirm the MRI results. Behavior test was assessed with Basso, Beattie, and Bresnahan (BBB) scoring in 6weeks after cell transplantation. The Gd-labeled MSCs showed a significant increase in signal intensity in T1-weighted images. After local transplantation, Gd-DTPA-labeled MSCs could be detected in SCI rat models by the persistent T1-weighted positive enhancement from 3 to 14days. Under electronic microscope, Gd-DTPA/jetPEI complexes were mostly observed in cytoplasm. Fluorescence microscopy examination showed that the Gd-labeled MSCs survived and distributed within the injured spinal cord until 2weeks. The Gd-labeled MSCs were identified and tracked with MRI by cross and sagittal sections. The BBB scores of the rats with labeled MSCs transplantation were significantly higher than those of control rats. Our results demonstrated that Gd-DTPA is appropriate for cell tracking in rat model of SCI, indicating that an efficient and nontoxic label method with Gd-DTPA could properly track MSCs in hemorrhage animal models.

Baicalein inhibits formation of α-synuclein oligomers within living cells and prevents Aβ peptide fibrillation and oligomerisation

Abnormal protein aggregation in the brain is linked to the pathogenesis of neurodegenerative diseases, including Alzheimer's disease (AD) and Parkinson's disease (PD). Recent studies revealed that the oligomeric form of aggregates is most likely the toxic species, and thus could be a good therapeutic target. To screen for potent inhibitors that can inhibit both oligomerisation and fibrillation of α-synuclein (α-syn), we systematically compared the antioligomeric and antifibrillar activities of eight compounds that were extracted from Chinese herbal medicines through three platforms that can monitor the formation of α-syn fibrils and oligomers in cell-free or cellular systems. Our results revealed that baicalein, a flavonoid extracted from the Chinese herbal medicine Scutellaria baicalensis Georgi ("huang qin" in Chinese), is a potent inhibitor of α-syn oligomerisation both in cell-free and cellular systems, and is also an effective inhibitor of α-syn fibrillation in cell-free systems. We further tested the protective effect of baicalein against α-syn-oligomer-induced toxicity in neuronal cells. Our data showed that baicalein inhibited the formation of α-syn oligomers in SH-SY5Y and Hela cells, and protected SH-SY5Y cells from α-syn-oligomer-induced toxicity. We also explored the effect of baicalein on amyloid-β peptide (Aβ) aggregation and toxicity. We found that baicalein can also inhibit Aβ fibrillation and oligomerisation, disaggregate pre-formed Aβ amyloid fibrils and prevent Aβ fibril-induced toxicity in PC12 cells. Our study indicates that baicalein is a good inhibitor of amyloid protein aggregation and toxicity. Given the role of these processes in neurodegenerative diseases such as AD and PD, our results suggest that baicalein has potential as a therapeutic agent for the treatment of these devastating disorders.

Combination effects of salvianolic acid B with low-dose celecoxib on inhibition of head and neck squamous cell carcinoma growth in vitro and in vivo

Head and neck squamous cell carcinoma (HNSCC) development is closely associated with inflammation. Cyclooxygenase-2 (COX-2) is an important mediator of inflammation. Therefore, celecoxib, a selective inhibitor of COX-2, was hailed as a promising chemopreventive agent for HNSCC. Dose-dependent cardiac toxicity limits long-term use of celecoxib, but it seems likely that this may be diminished by lowering its dose. We found that salvianolic acid B (Sal-B), isolated from Salvia miltiorrhiza Bge, can effectively suppress COX-2 expression and induce apoptosis in a variety of cancer cell lines. In this study, we report that combination of Sal-B with low-dose celecoxib results in a more pronounced anticancer effect in HNSCC than either agent alone. The combination effects were assessed in four HNSCC cell lines (JHU-06, JHU-011, JHU-013, and JHU-022) by evaluating cell viability, proliferation, and tumor xenograft growth. Cell viability and proliferation were significantly inhibited by both the combined and single-agent treatments. However, the combination treatment significantly enhanced anticancer efficacy in JHU-013 and JHU-022 cell lines compared with the single treatment regimens. A half-dose of daily Sal-B (40 mg/kg/d) and celecoxib (2.5 mg/kg/d) significantly inhibited JHU-013 xenograft growth relative to mice treated with a full dose of Sal-B or celecoxib alone. The combination was associated with profound inhibition of COX-2 and enhanced induction of apoptosis. Taken together, these results strongly suggest that combination of Sal-B, a multifunctional anticancer agent, with low-dose celecoxib holds potential as a new preventive strategy in targeting inflammatory-associated tumor development.

A systematic review of cellular transplantation therapies for spinal cord injury

Cell transplantation therapies have become a major focus in pre-clinical research as a promising strategy for the treatment of spinal cord injury (SCI). In this article, we systematically review the available pre-clinical literature on the most commonly used cell types in order to assess the body of evidence that may support their translation to human SCI patients. These cell types include Schwann cells, olfactory ensheathing glial cells, embryonic and adult neural stem/progenitor cells, fate-restricted neural/glial precursor cells, and bone-marrow stromal cells. Studies were included for review only if they described the transplantation of the cell substrate into an in-vivo model of traumatic SCI, induced either bluntly or sharply. Using these inclusion criteria, 162 studies were identified and reviewed in detail, emphasizing their behavioral effects (although not limiting the scope of the discussion to behavioral effects alone). Significant differences between cells of the same "type" exist based on the species and age of donor, as well as culture conditions and mode of delivery. Many of these studies used cell transplantations in combination with other strategies. The systematic review makes it very apparent that cells derived from rodent sources have been the most extensively studied, while only 19 studies reported the transplantation of human cells, nine of which utilized bone-marrow stromal cells. Similarly, the vast majority of studies have been conducted in rodent models of injury, and few studies have investigated cell transplantation in larger mammals or primates. With respect to the timing of intervention, nearly all of the studies reviewed were conducted with transplantations occurring subacutely and acutely, while chronic treatments were rare and often failed to yield functional benefits.

SMND-309, a novel derivate of salvianolic acid B, ameliorates cerebral infarction in rats: characterization and role

(2E)-2-{6-[(E)-2-carboxylvinyl]-2,3-dihydroxyphenyl}-3-(3,4-dihydroxyphenyl) propenoic acid, a novel compound designated SMND-309, is a new degradation product of salvianolic acid B. The present study was conducted to evaluate whether SMND-309 has a protective effect on permanent focal cerebral ischemia in rats. The results showed that SMND-309 at doses higher than 4.0 mg/kg (i.v.) produced a significant neuroprotection in focal ischemia rats when administered 30 min after the onset of ischemia. SMND-309 (25.0 mg/kg, i.v.) demonstrated significant neuroprotective activity even after delayed administration at 1 h, 3 h and 6 h after ischemia. The neuroprotective effect of SMND-309 (25.0 mg/kg, bolus injection intravenous at 30 min after middle cerebral artery occlusion) was still present 7 days after ischemia. Meanwhile, SMND-309 significantly increased the brain ATP content, improved mitochondrial energy metabolism and mitochondrial respiratory chain complex activities and attenuated the elevation of malondialdehyde (MDA) content, the decrease in superoxide dismutase (SOD) and glutathione-peroxidase (GSH-Px) activity in brain mitochondria. All of these findings indicate that SMND-309 exerts potent and long-term neuroprotective effects with a favorable therapeutic time-window in the model of permanent cerebral ischemia, and its protective effects may be due to the amelioration of cerebral mitochondrial energy metabolism and the antioxidant property.