Neuroprotective effects of ginsenoside Rg1-induced neural stem cell transplantation on hypoxic-ischemic encephalopathy

Advances in Engineered Nanoparticles for the Treatment of Ischemic Stroke by Enhancing Angiogenesis

Angiogenesis, or the formation of new blood vessels, is a natural defensive mechanism that aids in the restoration of oxygen and nutrition delivery to injured brain tissue after an ischemic stroke. Angiogenesis, by increasing vessel development, may maintain brain perfusion, enabling neuronal survival, brain plasticity, and neurologic recovery. Induction of angiogenesis and the formation of new vessels aid in neurorepair processes such as neurogenesis and synaptogenesis. Advanced nano drug delivery systems hold promise for treatment stroke by facilitating efficient transportation across the the blood-brain barrier and maintaining optimal drug concentrations. Nanoparticle has recently been shown to greatly boost angiogenesis and decrease vascular permeability, as well as improve neuroplasticity and neurological recovery after ischemic stroke. We describe current breakthroughs in the development of nanoparticle-based treatments for better angiogenesis therapy for ischemic stroke employing polymeric nanoparticles, liposomes, inorganic nanoparticles, and biomimetic nanoparticles in this study. We outline new nanoparticles in detail, review the hurdles and strategies for conveying nanoparticle to lesions, and demonstrate the most recent advances in nanoparticle in angiogenesis for stroke treatment.

Ginsenosides on stem cells fate specification-a novel perspective

Recent studies have demonstrated that stem cells have attracted much attention due to their special abilities of proliferation, differentiation and self-renewal, and are of great significance in regenerative medicine and anti-aging research. Hence, finding natural medicines that intervene the fate specification of stem cells has become a priority. Ginsenosides, the key components of natural botanical ginseng, have been extensively studied for versatile effects, such as regulating stem cells function and resisting aging. This review aims to summarize recent progression regarding the impact of ginsenosides on the behavior of adult stem cells, particularly from the perspective of proliferation, differentiation and self-renewal.

Neuronal differentiation and functional maturation of neurons from neural stem cells induced by bFGF-chitosan controlled release system

Available methods for differentiating stem cells into neurons require a large number of cytokines and neurotrophic factors, with complex steps and slow processes, and are inefficient to produce functional neurons and form synaptic contacts, which is expensive and impractical in clinical application. Here, we demonstrated a bioactive material, basic fibroblast growth factor (bFGF)-chitosan controlled release system, for facilitating neuronal differentiation from NSCs and the functional maturation of the induced neurons with high efficiency. We illustrated by immunostaining that the neurons derived from NSCs expressed mature immunomarkers of interneurons and excitatory neurons. And we found by patch-clamp that the induced neurons exhibited diverse electrophysiological properties as well as formed functional synapses. In vivo, we implanted bFGF-chitosan into lesion area in traumatic brain injury (TBI) mice and similarly observed abundance of neuroblasts in SVZ and the presence of newborn functional neurons in injury area, which integrated into synaptic networks. Taken together, our efficient and rapid tissue engineering approach may be a potential method for the generation of functional neuronal lineage cells from stem cells and a therapy of brain injury and disease.

Post-stroke cognitive impairment and synaptic plasticity: A review about the mechanisms and Chinese herbal drugs strategies

Post-stroke cognitive impairment, is a major complication of stroke, characterized by cognitive dysfunction, which directly affects the quality of life. Post-stroke cognitive impairment highlights the causal relationship between stroke and cognitive impairment. The pathological damage of stroke, including the increased release of excitatory amino acids, oxidative stress, inflammatory responses, apoptosis, changed neurotrophic factor levels and gene expression, influence synaptic plasticity. Synaptic plasticity refers to the activity-dependent changes in the strength of synaptic connections and efficiency of synaptic transmission at pre-existing synapses and can be divided into structural synaptic plasticity and functional synaptic plasticity. Changes in synaptic plasticity have been proven to play important roles in the occurrence and treatment of post-stroke cognitive impairment. Evidence has indicated that Chinese herbal drugs have effect of treating post-stroke cognitive impairment. In this review, we overview the influence of pathological damage of stroke on synaptic plasticity, analyze the changes of synaptic plasticity in post-stroke cognitive impairment, and summarize the commonly used Chinese herbal drugs whose active ingredient or extracts can regulate synaptic plasticity. This review will summarize the relationship between post-stroke cognitive impairment and synaptic plasticity, provide new ideas for future exploration of the mechanism of post-stroke cognitive impairment, compile evidence of applying Chinese herbal drugs to treat post-stroke cognitive impairment and lay a foundation for the development of novel formulas for treating post-stroke cognitive impairment.

Ginsenoside Rg1 Inhibits High Glucose-Induced Proliferation, Migration, and Angiogenesis in Retinal Endothelial Cells by Regulating the lncRNA SNHG7/miR-2116-5p/SIRT3 Axis

Background

Diabetic retinopathy (DR), including retinal angiogenesis and endothelial cell proliferation and migration, is a serious complication in diabetic patients. It has been reported that ginsenoside Rg1 can prevent retinal damage. However, the mechanism by which Rg1 prevents retinal damage is unknown. Therefore, the aim of the present study was to investigate the mechanism by which Rg1 inhibits high glucose-induced complications through the regulation of the lncRNA SNHG7/miR-2116-5p/SIRT3 axis.

Methods

Under high glucose (HG) conditions, human retinal endothelial cells (HRECs) were cultured to simulate a DR environment, and Rg1 was added after 48 h. Negative control (NC), miR-2116-5p mimic, si-SNHG7, pc-DNA SIRT3, and miR-2116-5p inhibitor were transfected into HRECs, and CCK-8 assay was used to detect the cell viability. Angiogenesis and transwell assays were used to evaluate angiogenesis and cell migration, respectively. qRT-PCR and Western blot were used to detect the expression of related genes and proteins. Luciferase reporter assays and bioinformatics were used to analyze the target binding sites of miR-2116-5p to lncRNA SNHG7 and SIRT3.

Results

The proliferation, migration and angiogenesis of HRECs were induced by HG. As expected, HG upregulated miR-2116-5p and VEGF expression but downregulated lncRNA SNHG7 and SIRT3 expression. Importantly, Rg1 inhibited HG-induced HREC proliferation, migration, and angiogenesis by upregulating the lncRNA SNHG7, and miR-2116-5p had a target regulatory relationship with both lncRNA SNHG7 and SIRT3.

Conclusion

Rg1 inhibits HG-induced proliferation, migration, angiogenesis, and VEGF expression in retinal endothelial cells through the lncRNA SNG7/miR-2116-5p/SIRT3 axis. This finding provides theoretical evidence for the clinical application of Rg1 in DR.

Ginsenoside Rg1 mitigates morphine dependence via regulation of gut microbiota, tryptophan metabolism, and serotonergic system function

BACKGROUND

Morphine dependence, a devastating neuropsychiatric condition, may be closely associated with gut microbiota dysbiosis. Ginsenoside Rg1 (Rg1), an active ingredient extracted from the roots of Panax ginseng C.A. Meyer, has potential health-promoting effects on the nervous system. However, its role in substance use disorders remains unclear. Here, we explored the potential modulatory roles of Rg1 in protection against morphine dependence.

METHODS

Conditioned place preference (CPP) was used for establishing a murine model of morphine dependence. 16S rRNA gene sequencing and metabolomics were performed for microbial and metabolite analysis. Molecular analysis was tested for evaluating the host serum and brain responses.

RESULTS

Rg1 prevented morphine-induced CPP in mice. The 16S rRNA gene-based microbiota analysis demonstrated that Rg1 ameliorated morphine-induced gut microbiota dysbiosis, specifically for Bacteroidetes. Moreover, Rg1 also inhibited gut microbiota-derived tryptophan metabolism and reduced the serotonin, 5-hydroxytryptamine receptor 1B (5-HTR1B), and 5-hydroxytryptamine receptor 2 A (5-HTR2A) levels. However, the Rg1-induced amelioration of CPP was not observed in mice when their gut microbiome was depleted by non-absorbable antibiotics. Subsequently, gavage with Bacteroides vulgatus increased the abundance of Bacteroidetes. B. vulgatus supplementation synergistically enhanced Rg1-alleviated morphine-induced CPP in mice with microbiome knockdown. Co-treatment with B. vulgatus and Rg1 produced suppressive effects against morphine dependency by inhibiting tryptophan metabolism and reducing the serotonin and 5-HTR1B/5-HTR2A levels.

CONCLUSIONS

The gut microbiota-tryptophan metabolism-serotonin plays an important role in gut-brain signaling in morphine disorders, which may represent a novel approach for drug dependence treatment via manipulation of the gut microbial composition and tryptophan metabolite.

Neural stem cell treatment for perinatal brain injury: A systematic review and meta-analysis of preclinical studies

Perinatal brain injury can lead to significant neurological and cognitive deficits and currently no therapies can regenerate the damaged brain. Neural stem cells (NSCs) have the potential to engraft and regenerate damaged brain tissue. The aim of this systematic review was to evaluate the preclinical literature to determine whether NSC administration is more effective than controls in decreasing perinatal brain injury. Controlled interventional studies of NSC therapy using animal models of perinatal brain injury were identified using MEDLINE and Embase. Primary outcomes were brain infarct size, motor, and cognitive function. Data for meta‐analysis were synthesized and expressed as standardized mean difference (SMD) with 95% confidence intervals (CI), using a random effects model. We also reported secondary outcomes including NSC survival, migration, differentiation, and effect on neuroinflammation. Eighteen studies met inclusion criteria. NSC administration decreased infarct size (SMD 1.09; CI: 0.44, 1.74, P = .001; I² = 74%) improved motor function measured via the impaired forelimb preference test (SMD 2.27; CI: 0.85, 3.69, P = .002; I² = 86%) and the rotarod test (SMD 1.88; CI: 0.09, 3.67, P = .04; I² = 95%). Additionally, NSCs improved cognitive function measured via the Morris water maze test (SMD of 2.41; CI: 1.16, 3.66, P = .0002; I² = 81%). Preclinical evidence suggests that NSC therapy is promising for the treatment of perinatal brain injury. We have identified key knowledge gaps, including the lack of large animal studies and uncertainty regarding the necessity of immunosuppression for NSC transplantation in neonates. These knowledge gaps should be addressed before NSC treatment can effectively progress to clinical trial.

Traditional Chinese Medicine Monomers: Novel Strategy for Endogenous Neural Stem Cells Activation After Stroke

Stem cell therapy, which has become a potential regenerative medical treatment and a promising approach for treating brain injuries induced by different types of cerebrovascular disease, has various application methods. Activation of endogenous neural stem cells (NSCs) can enable infarcted neuron replacement and promote neural networks’ regeneration without the technical and ethical issues associated with the transplantation of exogenous stem cells. Thus, NSC activation can be a feasible strategy to treat central nervous system (CNS) injury. The potential molecular mechanisms of drug therapy for the activation of endogenous NSCs have gradually been revealed by researchers. Traditional Chinese medicine monomers (TCMs) are active components extracted from Chinese herbs, and some of them have demonstrated the potential to activate proliferation and neurogenesis of NSCs in CNS diseases. Ginsenoside Rg1, astragaloside IV (AST), icariin (ICA), salvianolic acid B (Sal B), resveratrol (RES), curcumin, artesunate (ART), and ginkgolide B (GB) have positive effects on NSCs via different signaling pathways and molecules, such as the Wingless/integrated/β-catenin (Wnt/β-catenin) signaling pathway, the sonic hedgehog (Shh) signaling pathway, brain-derived neurotrophic factor (BDNF), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase 1 (HO-1). This article may provide further motivation for researchers to take advantage of TCMs in studies on CNS injury and stem cell therapy.

Ginsenoside Rg1 Alleviates Podocyte Injury Induced by Hyperlipidemia via Targeting the mTOR/NF-κB/NLRP3 Axis

Background

Podocyte injury plays an important role in diabetic nephropathy (DN). The aim of this study was to determine the potential therapeutic effects of the ginsenoside Rg1 on hyperlipidemia-stressed podocytes and elucidate the underlying mechanisms.

Methods

In vitro and in vivo models of DN were established as previously described, and the expression levels of relevant markers were analyzed by Western blotting, real-time Polymerase Chain Reaction (PCR), immunofluorescence, and immunohistochemistry.

Results

Ginsenoside Rg1 alleviated pyroptosis in podocytes cultured under hyperlipidemic conditions, as well as in the renal tissues of diabetic rats, and downregulated the mammalian target of rapamycin (mTOR)/NF-κB pathway. In addition, Rg1 also inhibited hyperlipidemia-induced NLRP3 inflammasome in the podocytes, which was abrogated by the mTOR activator L-leucine (LEU). The antipyroptotic effects of Rg1 manifested as improved renal function in the DN rats.

Conclusion

Ginsenoside Rg1 protects podocytes from hyperlipidemia-induced damage by inhibiting pyroptosis through the mTOR/NF-κB/NLRP3 axis, indicating a potential therapeutic function in DN.

Strontium Modified Calcium Sulfate Hemihydrate Scaffold Incorporating Ginsenoside Rg1/Gelatin Microspheres for Bone Regeneration

The aim of this study was to prepare a promising biomaterial for bone tissue repair and regeneration. The Strontium - calcium sulfate hemihydrate (Sr-α-CaS) scaffold incorporating gelatin microspheres (GMs) encapsulated with Ginsenoside Rg1 (Rg1) was designed. The scaffolds of Rg1/GMs/Sr-α-CaS showed sustained release of Rg1, good biocompatibility and ability of promoting osteogenic differentiation and angiogenesis in vitro. The scaffolds were implanted into animal model of cranial bone defect to characterize bone tissue repair and regeneration in vivo. From the images of Micro-CT, it was obvious that the most bone tissue was formed in Rg1/GMs/Sr-α-CaS group in 12 weeks. New bone structure, collagen and mineralization were analyzed with staining of HE, Masson and Safranin O-Fast green and showed good distribution. The expression of osteocalcin of Rg1/GMs/Sr-α-CaS indicated new bone formation in defect site. The results revealed that synergy of Rg1 and Sr showed the best effect of bone repair and regeneration, which provided a new candidate for bone defect repair in clinic.

Hormesis and Ginseng: Ginseng Mixtures and Individual Constituents Commonly Display Hormesis Dose Responses, Especially for Neuroprotective Effects

This paper demonstrates that ginseng mixtures and individual ginseng chemical constituents commonly induce hormetic dose responses in numerous biological models for endpoints of biomedical and clinical relevance, typically providing a mechanistic framework. The principal focus of ginseng hormesis-related research has been directed toward enhancing neuroprotection against conditions such as Alzheimer's and Parkinson's Diseases, stroke damage, as well as enhancing spinal cord and peripheral neuronal damage repair and reducing pain. Ginseng was also shown to reduce symptoms of diabetes, prevent cardiovascular system damage, protect the kidney from toxicities due to immune suppressant drugs, and prevent corneal damage, amongst other examples. These findings complement similar hormetic-based chemoprotective reports for other widely used dietary-type supplements such as curcumin, ginkgo biloba, and green tea. These findings, which provide further support for the generality of the hormetic dose response in the biomedical literature, have potentially important public health and clinical implications.

Ginsenoside Rg1 Alleviates Podocyte EMT Passage by Regulating AKT/GSK3 β/β-Catenin Pathway by Restoring Autophagic Activity

Background

Diabetic nephropathy (DN), a complication of diabetes, is the result of high glucose-induced pathological changes in podocytes, such as epithelial-mesenchymal transition (EMT). Autophagy is an important mechanism of podocyte repair. Ginsenoside Rg1, the active ingredient of ginseng extract, has antifibrotic and proautophagic effects. Therefore, we hypothesized that ginsenoside Rg1 can reverse podocyte EMT via autophagy and alleviate DN.

Aim

This study aimed to investigate the effect of ginsenoside Rg1 on DN rats and high glucose-induced podocyte EMT by regulating the AKT/GSK3β/β/

Methods

Diabetic rats induced by STZ injection were treated with 50 mg/kg ginsenoside Rg1 for 8 weeks, and the renal functional, metabolic, and histopathological indices were evaluated. DN was simulated in vitro by exposing podocytes to high glucose levels and treated with ginsenoside Rg1. The expression of EMT and autophagy-related markers was analyzed in vivo and in vitro by exposing podocytes to high glucose levels and treated with ginsenoside Rg1. The expression of EMT and autophagy-related markers was analyzed

Results

Ginsenoside Rg1 significantly alleviated renal fibrosis and podocyte EMT in diabetic rats, and podocytes exposed to high glucose levels, which was abolished by the autophagy inhibitor 3-MA. Furthermore, ginsenoside Rg1 regulated the AKT/GSK3 β/β/

Conclusion

Ginsenoside Rg1 alleviated podocyte EMT by enhancing AKT/GSK3β/β-catenin pathway-mediated autophagy, indicating its therapeutic potential for DN and other glomerular diseases.β/β/

The protective mechanisms underlying Ginsenoside Rg1 effects on rat sciatic nerve injury

Ginsenoside Rg1 (GsRg1), derived from the herb Ginseng, was found to exert protective effects in nerve injury; however, the mechanisms underlying these effects remain to be determined. Oxidant stress and apoptosis are known to be involved in sciatic nerve injury. Thus, the aim of this study was to examine whether GsRg1 was able to modify sciatic nerve injury in a rat model. The following parameters were measured: (1) number of spinal cord motoneurons by Nissl staining, (2) oxidation parameters including spinal cord malondialdehyde (MDA) levels and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as (3) involvement of apoptosis by determining caspase-3 and X-linked inhibitor of apoptosis protein (XIAP) by immunohistochemistry and Western blot. The number of spinal cord motoneurons was significantly reduced after sciatic nerve injury, while treatment with GsRg1 markedly elevated cell number. Sciatic nerve injury markedly increased spinal cord MDA content concomitant with reduced activities of SOD and GSH-Px. GsRg1 significantly decreased MDA content accompanied by elevated activities of SOD and GSH-Px. Further nerve injury significantly diminished protein expression levels of XIAP accompanied by elevated protein expression levels of caspase-3 in the spinal cord. GsRg1 markedly increased protein expression levels of XIAP, but significantly reduced protein expression levels of caspase-3. Data suggest that the protective effects of GsRg1 in sciatic nerve injury may be associated with reduced oxidative stress involving anti-apoptotic pathways.

Fabrication and evaluation a transferrin receptor targeting nano-drug carrier for cerebral infarction treatment

After cerebral infarction, the regeneration of microvascular played an important role in the recovery. Ginsenoside Rg1 (Rg1) had good effects on promoting angiogenesis and neuro-protection in cerebral infarction treatment. However, the blood-brain barrier (BBB) restricted Rg1 to enter into cerebral tissue. Transferrin receptor (TfR) was over-expressed in the BBB. In this study, we fabricated a TfR targeting nano-carrier (PATRC) to penetrate the BBB for treatment of cerebral infarction. A TfR targeted peptide was conjugated with the nano-carrier wrapped hydrophobic Rg1. The nanoscale size (132 ± 12 nm), polydispersity index (PDI =0.29) and the zeta potential (-38mv) were tested with dynamic light scattering optical system. Surface morphology (ellipse, mean diameter 122 ± 26 nm) was detected by transmission electron microscope (TEM). PATRC implement cell targeting ability on rat brain microvascular endothelial cells RBE4 in vitro detected by immunofluorescence and flow cytometry methods. Comparing with Rg1 threated group, the PATRC exhibited more prominent ability on the tube formation ability (p < .05) in vitro. Comparing with the Rg1 treated group, PATRC penetrated BBB in vivo detected by HPLC, decreased the brain infarction volume tested with TTC staining and promoted regeneration of microvascular in infarction zone detected by CD31 immunofluorescence. PATRC has great potentiality for wide application in clinic.

Severe-combined immunodeficient rats can be used to generate a model of perinatal hypoxic-ischemic brain injury to facilitate studies of engrafted human neural stem cells

Cerebral palsy (CP) encompasses a group of non-progressive brain disorders that are often acquired through perinatal hypoxic-ischemic (HI) brain injury. Injury leads to a cascade of cell death events, resulting in lifetime motor and cognitive deficits. There are currently no treatments that can repair the resulting brain damage and improve functional outcomes. To date, preclinical research using neural precursor cell (NPC) transplantation as a therapy for HI brain injury has shown promise. To translate this treatment to the clinic, it is essential that human-derived NPCs also be tested in animal models, however, a major limitation is the high risk of xenograft rejection. A solution is to transplant the cells into immune-deficient rodents, but there are currently no models of HI brain injury established in such a cohort of animals. Here, we demonstrate that a model of HI brain injury can be generated in immune-deficient Prkdc knockout (KO) rats. Long-term deficits in sensorimotor function were similar between KO and wildtype (WT) rats. Interestingly, some aspects of the injury were more severe in KO rats. Additionally, human induced pluripotent stem cell derived (hiPSC)-NPCs had higher survival at 10 weeks post-transplant in KO rats when compared to their WT counterparts. This work establishes a reliable model of neonatal HI brain injury in Prkdc KO rats that will allow for future transplantation, survival, and long-term evaluation of the safety and efficacy of hiPSC-NPCs for neonatal brain damage. This model will enable critical preclinical translational research using human NPCs.

Treatment of glaucomatous optic nerve damage using ginsenoside Rg1 mediated by ultrasound targeted microbubble destruction

The treatment of glaucomatous optic nervedamage using ginsenoside Rg1 mediated by ultrasound targeted microbubbles destruction was evaluated. Thirty healthy New Zealand white rabbits were subjected to injection of 0.3% carbomer solution to establish glaucomatous optic nerve damage model. Rabbits were divided into 5 groups: control group, model group, model group + intravitreal injection of nerve growth factor (NGF) group, model group + intravitreal injection of ginsenoside Rg1 group (Rg1 group), model group + intravitreal injection of ginsenoside Rg1 + ultrasound microbubble group (ultrasound group), model group + ultrasound targeted microbubble destruction (ultrasound group). Intraocular pressures were compared at 1, 2 and 4 weeks after model establishment. Rabbits were sacrificed 4 weeks after model establishment to collect retinal tissue for H&E staining. Histological changes were observed and the retinal thickness was measured. Contents of malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide (NO) were measured by ELISA. Intraocular pressure was significantly higher in model group than in control group at 1 week (P<0.05). Intraocular pressure was significantly lower in the ultrasound group than in NGF group and Rg1 group at all time-points (P<0.05). The number of ganglion cells in model group was decreased significantly. Number of nuclear layer cells was significantly reduced. Thickest retina was found in control group and model group was the thinnest (P<0.05). Contents of MDA and NO in model group were significantly higher than those in NCF group and Rg1 group. SOD content in control group was higher than that in ultrasound group and model group (P<0.05). In conclusion, treatment of glaucomatous optic nerve damage using ginsenoside Rg1 mediated by ultrasound targeted microbubble destruction can reduce the level of oxidative stress, relieve intraocular pressure and reduce ganglion cell damage.

Current progress in the derivation and therapeutic application of neural stem cells

Neural stem cells (NSCs) have a unique role in neural regeneration. Cell therapy based on NSC transplantation is a promising tool for the treatment of nervous system diseases. However, there are still many issues and controversies associated with the derivation and therapeutic application of these cells. In this review, we summarize the different sources of NSCs and their derivation methods, including direct isolation from primary tissues, differentiation from pluripotent stem cells and transdifferentiation from somatic cells. We also review the current progress in NSC implantation for the treatment of various neural defects and injuries in animal models and clinical trials. Finally, we discuss potential optimization strategies for NSC derivation and propose urgent challenges to the clinical translation of NSC-based therapies in the near future.

Protective effect of ginsenoside Rb1 against tacrolimus-induced apoptosis in renal proximal tubular LLC-PK1 cells

Background

The aim of the present study was to evaluate the potential protective effects of six ginsenosides (Rb1, Rb2, Rc, Rd, Rg1, and Rg3) isolated from Panax ginseng against tacrolimus (FK506)-induced apoptosis in renal proximal tubular LLC-PK1 cells.

Methods

LLC-PK1 cells were treated with FK506 and ginsenosides, and cell viability was measured. Protein expressions of mitogen-activated protein kinases, caspase-3, and kidney injury molecule-1 (KIM-1) were evaluated by Western blotting analyses. The number of apoptotic cells was measured using an image-based cytometric assay.

Results

Reduction in cell viability by 60μM FK506 was ameliorated significantly by cotreatment with ginsenosides Rg1 and Rb1. The phosphorylation of p38, extracellular signal-regulated kinases, and KIM-1, and cleavage of caspase-3, increased markedly in LLC-PK1 cells treated with FK506 and significantly decreased after cotreatment with ginsenoside Rb1. The number of apoptotic cells decreased by 6.0% after cotreatment with ginsenoside Rb1 (10μM and 50μM).

Conclusion

The antiapoptotic effects of ginsenoside Rb1 on FK506-induced apoptosis were mediated by the inhibition of mitogen-activated protein kinases and caspase activation.

Baicalin protects neonatal rat brains against hypoxic-ischemic injury by upregulating glutamate transporter 1 via the phosphoinositide 3-kinase/protein kinase B signaling pathway

Baicalin is a flavonoid compound extracted from Scutellaria baicalensis root. Recent evidence indicates that baicalin is neuroprotective in models of ischemic stroke. Here, we investigate the neuroprotective effect of baicalin in a neonatal rat model of hypoxic-ischemic encephalopathy. Seven-day-old pups underwent left common carotid artery ligation followed by hypoxia (8% oxygen at 37°C) for 2 hours, before being injected with baicalin (120 mg/kg intraperitoneally) and examined 24 hours later. Baicalin effectively reduced cerebral infarct volume and neuronal loss, inhibited apoptosis, and upregulated the expression of p-Akt and glutamate transporter 1. Intracerebroventricular injection of the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) inhibitor LY294002 30 minutes before injury blocked the effect of baicalin on p-Akt and glutamate transporter 1, and weakened the associated neuroprotective effect. Our findings provide the first evidence, to our knowledge that baicalin can protect neonatal rat brains against hypoxic-ischemic injury by upregulating glutamate transporter 1 via the PI3K/Akt signaling pathway.

Molecular chaperones and hypoxic-ischemic encephalopathy

Hypoxic-ischemic encephalopathy (HIE) is a disease that occurs when the brain is subjected to hypoxia, resulting in neuronal death and neurological deficits, with a poor prognosis. The mechanisms underlying hypoxic-ischemic brain injury include excitatory amino acid release, cellular proteolysis, reactive oxygen species generation, nitric oxide synthesis, and inflammation. The molecular and cellular changes in HIE include protein misfolding, aggregation, and destruction of organelles. The apoptotic pathways activated by ischemia and hypoxia include the mitochondrial pathway, the extrinsic Fas receptor pathway, and the endoplasmic reticulum stress-induced pathway. Numerous treatments for hypoxic-ischemic brain injury caused by HIE have been developed over the last half century. Hypothermia, xenon gas treatment, the use of melatonin and erythropoietin, and hypoxic-ischemic preconditioning have proven effective in HIE patients. Molecular chaperones are proteins ubiquitously present in both prokaryotes and eukaryotes. A large number of molecular chaperones are induced after brain ischemia and hypoxia, among which the heat shock proteins are the most important. Heat shock proteins not only maintain protein homeostasis; they also exert anti-apoptotic effects. Heat shock proteins maintain protein homeostasis by helping to transport proteins to their target destinations, assisting in the proper folding of newly synthesized polypeptides, regulating the degradation of misfolded proteins, inhibiting the aggregation of proteins, and by controlling the refolding of misfolded proteins. In addition, heat shock proteins exert anti-apoptotic effects by interacting with various signaling pathways to block the activation of downstream effectors in numerous apoptotic pathways, including the intrinsic pathway, the endoplasmic reticulum-stress mediated pathway and the extrinsic Fas receptor pathway. Molecular chaperones play a key role in neuroprotection in HIE. In this review, we provide an overview of the mechanisms of HIE and discuss the various treatment strategies. Given their critical role in the disease, molecular chaperones are promising therapeutic targets for HIE.

Protective mechanisms of microRNA-27a against oxygen-glucose deprivation-induced injuries in hippocampal neurons

Hypoxic injuries during fetal distress have been shown to cause reduced expression of microRNA-27a (miR-27a), which regulates sensitivity of cortical neurons to apoptosis. We hypothesized that miR-27a overexpression attenuates hypoxia- and ischemia-induced neuronal apoptosis by regulating FOXO1, an important transcription factor for regulating the oxidative stress response. miR-27a mimic was transfected into hippocampal neurons to overexpress miR-27a. Results showed increased hippocampal neuronal viability and decreased caspase-3 expression. The luciferase reporter gene system demonstrated that miR-27a directly binded to FOXO1 3'UTR in hippocampal neurons and inhibited FOXO1 expression, suggesting that FOXO1 was the target gene for miR-27a. These findings confirm that miR-27a protects hippocampal neurons against oxygen-glucose deprivation-induced injuries. The mechanism might be mediated by modulation of FOXO1 and apoptosis-related gene caspase-3 expression.

Protective effects of ginsenoside Rg1 against hydrogen peroxide-induced injury in human neuroblastoma cells

The active ingredient of ginseng, ginsenosides Rg1, has been shown to scavenge free radicals and improve antioxidant capacity. This study hypothesized that ginsenosides Rg1 has a protective role in human neuroblastoma cells injured by H2O2. Ginsenosides Rg1 at different concentrations (50 and 100 μM) was used to treat H2O2 (150 μM)-injured SH-SY5Y cells. Results demonstrated that ginsenoside Rg1 elevated the survival rate of SH-SY5Y cells injured by H2O2, diminished the amount of leaked lactate dehydrogenase, and increased superoxide dismutase activity. Ginsenoside Rg1 effectively suppressed caspase-3 immunoreactivity, and contributed to heat shock protein 70 gene expression, in a dose-dependent manner. These results indicate that ginsenoside Rg1 has protective effects on SH-SY5Y cells injured by H2O2 and that its mechanism of action is associated with anti-oxidation and the inhibition of apoptosis.

Ginsenoside Rg1 inhibits angiotensin II-induced podocyte autophagy via AMPK/mTOR/PI3K pathway

Recent researches have reported the extensive pharmacological activities of Ginsenoside Rg1 including antioxidant, anti-inflammatory, and anticancer properties. Furthermore Rg1 was also shown to protect various kinds of cells from self-digestion by its anti-autophagy activity. In previous studies, angiotensin II (Ang II), a key mediator of renin-angiotensin system, has been demonstrated to contribute to the progression of renal injury including abnormal autophagy. However, whether Rg1 can relieve Ang II-induced autophagy in podocyte as well as the underlying molecular mechanism remains to be elucidated. Here, we employed Ang II-treated podocyte as a model to investigate the effect of Rg1 on autophagy and the involved signal pathways. In the present study, we found that Ang II strongly promoted autophagy in immortalized mouse podocyte cells by observing the formation of autophagosomes and detecting the expression of autophagic marker, for example, LC3-II. Notably, compared to the Ang II-treated cells, treatment with Rg1 significantly inhibited the formation of autophagosomes and expression of autophagy-related proteins in Ang II pre-treated podocyte. Meanwhile, Rg1 downregulated the activity of AMPK and GSK-3β and upregulated the activity of P70S6K in Ang II-treated podocyte. In conclusion, these findings demonstrate that Ang II promotes autophagy in podocyte, and Rg1 effectively attenuates this process through AMPK/mTOR/PI3K pathway, suggesting that Rg1 may be beneficial to alleviate podocyte injury.

Pharmacokinetics of ginsenoside Rg1 in rat medial prefrontal cortex, hippocampus, and lateral ventricle after subcutaneous administration

The present study aimed to investigate pharmacokinetics of Rg1 in rat medial prefrontal cortex (mPFC), hippocampus (HIP), and lateral ventricle (LV) after subcutaneous injection. For the first time, intracerebral pharmacokinetics of Rg1 was studied in freely moving rats by microdialysis technique. Rg1 concentrations in dialysates were detected by a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method and were revised using in vivo probe-recovery in HIP and LV. The pharmacokinetic parameters were then determined using non-compartmental models. Since the in vivo recoveries remained stable in HIP and LV during 9 h dialysis, average recoveries were used to revise dialysate concentrations. After dosing, Rg1 was soon detected in brain extracellular fluid (bECF) and cerebrospinal fluid (CSF). The elimination of Rg1 was significantly slower in mPFC than in HIP and LV, and significantly greater AUC was obtained in mPFC than in HIP. Rg1 kinetics in bECF and CSF indicate that Rg1 can go across the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier (BCSFB), and then immediately distribute to learning and memory-related regions in brain, which may lead to rapid pharmacological onset. There may be active transport and target-mediated disposition of Rg1 in the CNS, which need to be further clarified.

Ginsenoside Rg1 exerts a protective effect against Aβ₂₅₋₃₅-induced toxicity in primary cultured rat cortical neurons through the NF-κB/NO pathway

Ginsenoside Rg1 (Rg1) is a multipotent triterpene saponin extracted from ginseng, and has been proven to act as a nootropic agent against various types of neurological damage. The present study was designed to investigate the neuroprotective effect and the underlying mechanisms of Rg1 on apoptosis induced by β-amyloid peptide 25-35 (Aβ25-35) in primary cultured cortical neurons. The primary neurons were preincubated with 20 µM Rg1 for 24 h and exposed to 10 µM Aβ25-35 for 72 h. In the present study, we found that Rg1 prevented nuclear factor κ-light-chain‑enhancer of activated B cells (NF-κB) nuclear translocation and IκB-α phosphorylation in primary cultured cortical neurons after Aβ25-35 exposure by scavenging excess reactive oxygen species (ROS); ROS was measured using DCFDA and examined using a fluorescence microscope. In addition, Rg1 successfully suppressed Aβ25‑35-inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production in a NF-κB-dependent manner; the suppression of NO was clearly illustrated by the NO production assay. Pretreatment of the cells with Rg1 elevated the proportion of Bcl-2/Bax, lessened the release of cytochrome c from mitochondria into cytoplasm and then blocked mitochondrial apoptotic cascades after Aβ25-35 insult by lowering NO generation. Taken together, our data demonstrate that Rg1 rescues primary cultured cortical neurons from Aβ25-35-induced cell apoptosis through the downregulation of the NF-κB/NO signaling pathway.

Transplantation of vascular endothelial growth factor-modified neural stem/progenitor cells promotes the recovery of neurological function following hypoxic-ischemic brain damage

Neural stem/progenitor cell (NSC) transplantation has been shown to effectively improve neurological function in rats with hypoxic-ischemic brain damage. Vascular endothelial growth factor (VEGF) is a signaling protein that stimulates angiogenesis and improves neural regeneration. We hypothesized that transplantation of VEGF-transfected NSCs would alleviate hypoxic-ischemic brain damage in neonatal rats. We produced and transfected a recombinant lentiviral vector containing the VEGF₁₆₅ gene into cultured NSCs. The transfected NSCs were transplanted into the left sensorimotor cortex of rats 3 days after hypoxic-ischemic brain damage. Compared with the NSCs group, VEGF mRNA and protein expression levels were increased in the transgene NSCs group, and learning and memory abilities were significantly improved at 30 days. Furthermore, histopathological changes were alleviated in these animals. Our findings indicate that transplantation of VEGF-transfected NSCs may facilitate the recovery of neurological function, and that its therapeutic effectiveness is better than that of unmodified NSCs.