Regulation of NAD+/NADH Redox Involves the Protective Effects of Ginsenoside Rb1 against Oxygen-Glucose Deprivation/Reoxygenation-Induced Astrocyte Lesions.

The aim of this study was to investigate NAD+/NADH redox regulation in astrocytes by Ginsenoside Rb1 subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) and to reveal the neuroprotective mechanism of ginseng. Neonatal mouse brain was used to culture primary astrocytes. The third generation of the primary astrocytes was used for the experiments. OGD/R was introduced by culturing the cells in a glucose-free media under nitrogen for 6 h followed by a regular culture for 24 h. Ginsenoside Rb1 attenuated OGD/R-induced astrocyte injury in a dose-dependent manner. It improved the mitochondrial function of OGD/R astrocytes indicated by improving mitochondrial distribution, increasing mitochondrial membrane potential, and enhancing mitochondrial DNA copies and ATP production. Ginsenoside Rb1 significantly lifted intracellular NAD+/NADH, NADPH/NADP+, and GSH/GSSG in OGD/R astrocytes. It inhibited the protein expression of both PARP1 and CD38, while attenuating the SIRT1 drop in OGD/R cells. In line with its effects on PARP1, Ginsenoside Rb1 significantly reduced the expression of poly-ADP-ribosylation (PARylation) proteins in OGD/R cells. Ginsenoside Rb1 also significantly increased the expression of NAMPT and NMNAT2, both of which are key players in NAD/NADH synthesis. The results suggest that the regulation of NAD+/NADH redox involves the protective effects of ginsenoside Rb1 against OGD/R-induced astrocyte injury.

Study on South African Indigenous Teas-Antioxidant Potential, Nutritional Content, and Hypoxia-Induced Cyclooxygenase Inhibition on U87 MG Cell Line.

Background: This study comparatively assessed seven indigenous traditional tea plants on several attributes that included antioxidant, nutritional, caffeine contents, and cyclooxygenase activity. Methodology: Nutritional content of all tea plants were determined for energy, fat, carbohydrates, total sugars, dietary fiber and amino acids. Antioxidant potential and the antioxidant potentiating secondary metabolites were also measured and compared. Further, we investigated the tea plants for any role they would have on cyclooxygenase (COX) activity on cobalt chloride (CoCl2) induced human glioma cell lines (U87MG). Results: The tea plants were found non-cytotoxic at concentrations tested against the human Chang liver and HeK 293 kidney cells and were found to be naturally caffeine free. The lowest and highest extraction yield among the tea plants was 7.1% for B. saligna and 15.48% for L. scaberrimma respectively. On average, the flavonol content was 12 to 8 QE/g, ORAC 800 µmol TE/g, TEAC 150 µmol TE/g, FRAP 155 µmol AAE/g, polyphenols 40 mg GAE/g, flavanols 0.35 mg CE/g, flavonols 12 mg QE/g and total flavonoid content (TFC) 180 µg QE/mg. The COX activity has been found to be inhibited by a dose-dependent manner by L. scaberrimma, B. saligna and L. javanica. Conclusion: The results further support competitive value of tea plants and need for improved and further development.

Ginsenoside Rb1 attenuates lipopolysaccharide-induced neural damage in the brain of mice via regulating the dysfunction of microglia and astrocytes.

The purpose of our research was to evaluate whether ginsenoside Rb1 has neuroprotective effects against lipopolysaccharide (LPS)-induced brain injury. ICR mice were intraperitoneally (i.p.) injected with 20 or 40 mg/kg Rb1 or saline for 7 consecutive days. On the 7th day, 30 minutes after Rb1 or saline administration, a single dose of LPS (LPS group, Rb1+LPS group) or saline (control group) was injected i.p. into the mice. Results demonstrated that Rb1 treatment could significantly improve the behavior performance of LPS mice in both the open field test and the beam walking test. Rb1 can also markedly attenuate the neuronal lesion in both hippocampus and somatosensory cortex in the brain of LPS mice. In addition, Rb1 treatment also significantly inhibits the LPS-induced neuroinflammation in the brain, indicated by reduced reactive microglia and decreased IL-1ß production. Both immunostaining and western blot results suggest that Rb1 can further enhance the LPS-induced GLT-1 expression and alleviate LPS-induced GS reduction in the brain. Our findings show that Rb1 has a protective effect on LPS-induced neuronal damage in the CA1 of the hippocampus and in the somatosensory area of the cerebral cortex in mice, which is likely to be the basis for its improvement of locomotor and motor coordination. Rb1 regulating the function of astrocytes and microglia through GLT-1 and GS in astrocytes may be involved in its neuroprotective effects.

Ginsenosides Rb1 and Rg1 Protect Primary Cultured Astrocytes against Oxygen-Glucose Deprivation/Reoxygenation-Induced Injury via Improving Mitochondrial Function.

This study aimed to evaluate whether ginsenosides Rb1 (20-S-protopanaxadiol aglycon) and Rg1 (20-S-protopanaxatriol aglycon) have mitochondrial protective effects against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury in primary mouse astrocytes and to explore the mechanisms involved. The OGD/R model was used to mimic the pathological process of cerebral ischemia-reperfusion in vitro. Astrocytes were treated with normal conditions, OGD/R, OGD/R plus Rb1, or OGD/R plus Rg1. Cell viability was measured to evaluate the cytotoxicity of Rb1 and Rg1. Intracellular reactive oxygen species (ROS) and catalase (CAT) were detected to evaluate oxidative stress. The mitochondrial DNA (mtDNA) copy number and mitochondrial membrane potential (MMP) were measured to evaluate mitochondrial function. The activities of the mitochondrial respiratory chain (MRC) complexes I-V and the level of cellular adenosine triphosphate (ATP) were measured to evaluate oxidative phosphorylation (OXPHOS) levels. Cell viability was significantly decreased in the OGD/R group compared to the control group. Rb1 or Rg1 administration significantly increased cell viability. Moreover, OGD/R caused a significant increase in ROS formation and, subsequently, it decreased the activity of CAT and the mtDNA copy number. At the same time, treatment with OGD/R depolarized the MMP in the astrocytes. Rb1 or Rg1 administration reduced ROS production, increased CAT activity, elevated the mtDNA content, and attenuated the MMP depolarization. In addition, Rb1 or Rg1 administration increased the activities of complexes I, II, III, and V and elevated the level of ATP, compared to those in the OGD/R groups. Rb1 and Rg1 have different chemical structures, but exert similar protective effects against astrocyte damage induced by OGD/R. The mechanism may be related to improved efficiency of mitochondrial oxidative phosphorylation and the reduction in ROS production in cultured astrocytes.

Ginsenoside Rb1 Attenuates High Glucose-Induced Oxidative Injury via the NAD-PARP-SIRT Axis in Rat Retinal Capillary Endothelial Cells.

(1) Aims: The present study aimed to observe the effects of Ginsenoside Rb1 on high glucose-induced endothelial damage in rat retinal capillary endothelial cells (RCECs) and to investigate the underlying mechanism. (2) Methods: Cultured RCECs were treated with normal glucose (5.5 mM), high glucose (30 mM glucose), or high glucose plus Rb1 (20 µM). Cell viability, lactate dehydrogenase (LDH) levels, the mitochondrial DNA copy number, and the intracellular ROS content were measured to evaluate the cytotoxicity. Superoxide dismutase (SOD), catalase (CAT), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX), poly(ADP-ribose) polymerase (PARP), and sirtuin (SIRT) activity was studied in cell extracts. Nicotinamide adenine dinucleotide (NAD+)/NADH, NADPH/NADP+, and glutathione (GSH)/GSSG levels were measured to evaluate the redox state. The expression of nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1), SIRT1, and SIRT3 was also evaluated after Rb1 treatment. (3) Results: Treatment with Rb1 significantly increased the cell viability and mtDNA copy number, and inhibited ROS generation. Rb1 treatment increased the activity of SOD and CAT and reduced the activity of NOX and PARP. Moreover, Rb1 enhanced both SIRT activity and SIRT1/SIRT3 expression. Additionally, Rb1 was able to re-establish the cellular redox balance in RCECs. However, Rb1 showed no effect on NMNAT1 expression in RCECs exposed to high glucose. (4) Conclusion: Under high glucose conditions, decreases in the reducing power may be linked to DNA oxidative damage and apoptosis via activation of the NMNAT-NAD-PARP-SIRT axis. Rb1 provides an advantage during high glucose-induced cell damage by targeting the NAD-PARP-SIRT signaling pathway and modulating the redox state in RCECs.

New perspectives on dietary-derived treatments and food safety-antinomy in a new era.

Despite the advances in science and technology and wide use of chemical drugs, dietary intervention (or food therapy) remains useful in preventing or treating many human diseases. A huge body of evidence shows that the dietary pattern or habit is also an important contributing factor to the development of chronic diseases such as hypertension, type 2 diabetes, hyperlipidemia, and cancers. In recent years, over-the-counter health foods, nutraceuticals, and plant-derived medicinal products have been gaining popularity all over the world, particularly in developed countries. Unfortunately, owing to the contamination with various harmful substances in foods and the presence of toxic food components, food-borne diseases have also become increasingly problematic. Incidents of food poisonings or tainted food have been increasing worldwide, particularly in China and other developing countries. Therefore, the government should put in a greater effort in enforcing food safety by improving the surveillance mechanism and exerting highest standards of quality control for foods.

Acute and sub-chronic toxicity studies of the extract of Thunberg Fritillary Bulb.

The aim of this study was to investigate the acute and sub-chronic toxicity of extract of Thunberg Fritillary Bulb. For the acute toxicity tests, graded doses of the extract were administered orally to mice. The animals were observed for toxic symptoms and mortality daily for 14days. In the sub-chronic toxicity study, rats were orally administered the extract at doses of 1 and 3mg/kg body weight (BW) for 26weeks. After 26weeks, the rats were sacrificed for hematological, biochemical and histological examination. In the acute toxicity tests, the estimated median lethal dosage (LD50) was 52.2mg/kg body weight in the mice. In the sub-chronic toxicity tests, a dose of 1mg/kg body weight presented no toxicity. Above the 1mg/kg dose, the main adverse signs observed in male rats were body or head tremor and spontaneous motor activity reduction. There were no other significant changes observed in hematology, blood biochemistry, organ weight and organ histology. The overall findings of this study indicate that the extract of Thunberg Fritillary Bulb is non-toxic up to 1mg/kg body weight, which can be considered a safe application dose.

[Nardosinone reduces neuronal injury induced by oxygen-glucose deprivation in primary cortical cultures].

The aim of the study is to investigate the effect of nardosinone (Nar) on neuronal injury induced by oxygen-glucose deprivation (OGD) in primary cortical cultures isolated from embryos at gestational day 14. MTT method was used to determine the dosage regimen of Nar in primary neuronal cultures and observe the influence of Nar on the neurons suffering OGD; Western blotting analysis was used to detect expressions of protein kinase A (PKA), Ras related protein 1 (Rap1), mitogen-activated protein kinase kinase 1 (MEK1) and phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2) of OGD-injured or uninjured primary cultured neurons after Nar treatment. Results showed that Nar (50 and 100 micromol x L(-1)) improved the cell viability during OGD damage (P < 0.01) and increased the expression of PKA, Rap1, MEK1 and p-ERK1/2 in injured neurons. Additionally, elevations of PKA, Rapl, MEK1 and p-ERK1/2 in uninjured neurons were caused by Nar (50, 100 and 200 micromol x L(-1)) with a dose-dependent tenclency as well (P < 0.01). In conclusion, Nar could protect against the neuronal injury exposed to OGD, which may be relevant to the promotion of PKA and ERK signaling pathway.

New perspectives on complementary and alternative medicine: an overview and alternative therapy.

Since 1990, tremendous progress in the medical sciences has precipitated significant improvements in health care. However, with the aging of populations worldwide, more people suffer from noncommunicable disease (NCD), incurable diseases, and/or poor health. The World Health Organization estimated that of the 57 million global deaths in 2008, 36 million were due to NCDs. These pose a considerable challenge to clinicians worldwide, particularly in developed nations. Complementary and alternative medicine (CAM) provides an array of treatment modalities for health promotion. CAM therapy can be divided into two major strategies; namely, herb-based CAM therapy and non-herb based CAM therapy. In the current commentary, we suggest a new understanding of CAM therapy and propose a new classification for CAM therapy as well as alternative therapies. With such information, CAM can be better utilized to benefit to populations worldwide.

Normoxic versus hyperoxic resuscitation in pediatric asphyxial cardiac arrest: effects on oxidative stress.

OBJECTIVE: To determine the effects of normoxic vs. hyperoxic resuscitation on oxidative stress in a model of pediatric asphyxial cardiac arrest. DESIGN: Prospective, interventional study. SETTING: University research laboratory. SUBJECTS: Postnatal day 16-18 rats (n = 5 per group). INTERVENTIONS: Rats underwent asphyxial cardiac arrest for 9 min. Rats were randomized to receive 100% oxygen, room air, or 100% oxygen with polynitroxyl albumin (10 mL·kg⁻¹ intravenously, 0 and 30 min after resuscitation) for 1 hr from the start of cardiopulmonary resuscitation. Shams recovered in 100% oxygen or room air after surgery. MEASUREMENTS AND MAIN RESULTS: Physiological variables were recorded at baseline to 1 hr after resuscitation. At 6 hrs after asphyxial cardiac arrest, levels of reduced glutathione and protein-thiols (fluorescent assay), activities of total superoxide dismutase and mitochondrial manganese superoxide dismutase (cytochrome c reduction method), manganese superoxide dismutase expression (Western blot), and lipid peroxidation (4-hydroxynonenal Michael adducts) were evaluated in brain tissue homogenates. Hippocampal 3-nitrotyrosine levels were determined by immunohistochemistry 72 hrs after asphyxial cardiac arrest. Survival did not differ among groups. At 1 hr after resuscitation, Pao2, pH, and mean arterial pressure were decreased in room air vs. 100% oxygen rats (59 ± 3 vs. 465 ± 46 mm Hg, 7.36 ± 0.05 vs. 7.42 ± 0.03, 35 ± 4 vs. 45 ± 5 mm Hg; p < .05). Rats resuscitated with 100% oxygen had decreased hippocampal reduced glutathione levels vs. sham (15.3 ± 0.4 vs. 20.9 ± 4.1 nmol·mg protein⁻¹; p < .01). Hippocampal manganese superoxide dismutase activity was significantly increased in 100% oxygen rats vs. sham (14 ± 2.4 vs. 9.5 ± 1.6 units·mg protein⁻¹, p < .01), with no difference in protein expression of manganese superoxide dismutase. Room air and 100% oxygen plus polynitroxyl albumin groups had hippocampal reduced glutathione and manganese superoxide dismutase activity levels comparable with sham. Protein thiol levels were unchanged across groups. Compared with all other groups, rats receiving 100% oxygen had increased immunopositivity for 3-nitrotyrosine in the hippocampus and increased lipid peroxidation in the cortex. CONCLUSIONS: Resuscitation with 100% oxygen leads to increased oxidative stress in a model that mimics pediatric cardiac arrest. This may be prevented by using room air or giving an antioxidant with 100% oxygen resuscitation.

[Regulation of microglia on neurogenesis in adult mammals].

Adult neurogenesis had been confirmed in rodents and other mammals for decades. The mechanisms underlying neurogenesis have been investigated extensively in recent years. Microglial cells, an immuno-cell in the central nervous system, have been found playing important roles in modulating the process of adult neurogenesis. The inflammatory microenvironment contributed by microglia are harmful to the survival of new born neurons. On the other hand, by interacting with T cells, microglia could act as a trophic factor for neurogenesis, most possibly by releasing growth factors. We reviewed the progress on how microglia regulating adult neurogenesis in variant pathological conditions. To understand the relationship between microglia and neurogenesis will help us to approach for promising therapeutic strategy for neuronal injury.

[Salvianolic acid B alleviate the disruption of blood-brain barrier in rats after cerebral ischemia-reperfusion by inhibiting MAPK pathway].

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.

Panax notoginseng for Cerebral Ischemia: A Systematic Review.

Panax notoginseng is the most widely used Chinese medicinal herb for the prevention and treatment of ischemic diseases. Its main active ingredients are saponins, including ginsenoside Rb1, ginsenoside Rg1, and notoginsenoside R1, among others. This review provides an up-to-date overview on the pharmacological roles of P. notoginseng constituents in cerebral ischemia. The saponins of P. notoginseng induce a variety of pharmacological effects in the multiscale mechanisms of cerebral ischemic pathophysiology, including anti-inflammatory activity, reduction of oxidative stress, anti-apoptosis, inhibition of amino acid excitotoxicity, reduction of intracellular calcium overload, protection of mitochondria, repairing the blood-brain barrier, and facilitation of cell regeneration. Regarding cell regeneration, P. notoginseng not only promotes the proliferation and differentiation of neural stem cells, but also protects neurons, endothelial cells and astrocytes in cerebral ischemia. In conclusion, P. notoginseng may treat cerebrovascular diseases through multiple pharmacological effects, and the most critical ones need further investigation.

Exposure to female estrous is beneficial for male mice against transient ischemic stroke.

OBJECTIVE: Exposure to female estrous, a natural rewarding experience, alleviates anxiety and depression, and the contribution of this behavior to stroke outcome is unknown. The aim of this study was to evaluate whether exposure to female estrous is beneficial to recovery following transient ischemic stroke in male mice. METHODS: Cerebral ischemia was induced in male ICR mice with thread occlusion of the middle cerebral artery (MCAO) for 30 min followed by reperfusion. MCAO mice were randomly divided into MCAO group and Estrous Female Exposure (EFE) group. The mice in the EFE group were subjected to estrous female mouse interaction from day 1 until the end of the experiment. Mortality was recorded during the investigation. Behavioral functions were assessed by a beam-walking test and corner test from day 1 to day 10 after MCAO. Serum testosterone levels were analyzed with ELISA, and the expression levels of growth-associated protein-43 (GAP-43) and synaptophysin in the cortex of the ischemic hemisphere were determined by western blot on day 7 after MCAO. RESULTS: Exposure to female estrous reduced the mortality induced by cerebral ischemic lesions. The beam-walking test demonstrated that exposure to female estrous significantly improved motor function recovery. The serum testosterone levels and ischemic cortex GAP-43 expression were significantly higher in MCAO male mice exposed to female estrous. CONCLUSION: Exposure to female estrous reduces mortality and improves functional recovery in MCAO male mice. The study provides the first evidence to support the importance of female interaction to male stroke rehabilitation. ABBREVIATIONS: GAP-43: growth-associated protein-43; SYP: Synaptophysin; MCAO: middle cerebral artery occlusion; OVXs: ovariectomies; CCA: common carotid artery; ECA: external carotid artery; EFE: estrous female exposure; TTC: 2,3,5-triphenyltetrazolium chloride; PAGE: polyacrylamide gel electrophoresis; PVDF: polyvinylidene difluoride; ANOVA: analysis of variance; LSD: least significant difference.

Mass-spectrometric characterization of phospholipids and their primary peroxidation products in rat cortical neurons during staurosporine-induced apoptosis.

The molecular diversity of phospholipids is essential for their structural and signaling functions in cell membranes. In the current work, we present, the results of mass spectrometric characterization of individual molecular species in major classes of phospholipids -- phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn), phosphatidylserine (PtdSer), phosphatidylinositol (PtdIns), sphingomyelin (CerPCho), and cardiolipin (Ptd(2)Gro) -- and their oxidation products during apoptosis induced in neurons by staurosporine (STS). The diversity of molecular species of phospholipids in rat cortical neurons followed the order Ptd(2)Gro > PtdEtn >> PtdCho >> PtdSer > PtdIns > CerPCho. The number of polyunsaturated oxidizable species decreased in the order Ptd(2)Gro >> PtdEtn > PtdCho > PtdSer > PtdIns > CerPCho. Thus a relatively minor class of phospholipids, Ptd(2)Gro, was represented in cortical neurons by the greatest variety of both total and peroxidizable molecular species. Quantitative fluorescence HPLC analysis employed to assess the oxidation of different classes of phospholipids in neuronal cells during intrinsic apoptosis induced by STS revealed that three anionic phospholipids -- Ptd(2)Gro >> PtdSer > PtdIns -- underwent robust oxidation. No significant oxidation in the most dominant phospholipid classes -- PtdCho and PtdEtn -- was detected. MS-studies revealed the presence of hydroxy-, hydroperoxy- as well as hydroxy-/hydroperoxy-species of Ptd(2)Gro, PtdSer, and PtdIns. Experiments in model systems where total cortex Ptd(2)Gro and PtdSer fractions were incubated in the presence of cytochrome c (cyt c) and H(2)O(2), confirmed that molecular identities of the products formed were similar to the ones generated during STS-induced neuronal apoptosis. The temporal sequence of biomarkers of STS-induced apoptosis and phospholipid peroxidation combined with recently demonstrated redox catalytic properties of cyt c realized through its interactions with Ptd(2)Gro and PtdSer suggest that cyt c acts as a catalyst of selective peroxidation of anionic phospholipids yielding Ptd(2)Gro and PtdSer peroxidation products. These oxidation products participate in mitochondrial membrane permeability transition and in PtdSer externalization leading to recognition and uptake of apoptotic cells by professional phagocytes.

[Effect of salvianolic acid B on neural cells damage and neurogenesis after brain ischemia-reperfusion in rats].

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.

Notoginsenoside R1 attenuates high glucose-induced endothelial damage in rat retinal capillary endothelial cells by modulating the intracellular redox state.

The aim of this study was to examine whether Notoginsenoside R1 (NR1) attenuates high glucose-induced cell damage in rat retinal capillary endothelial cells (RCECs) and to explore the mechanisms involved. The exposure of rat RCECs to high concentration of glucose (30 mM) for 72 h led to significant cytotoxicity, including decreased cell viability, reduced mitochondrial DNA copy number, increased lactate dehydrogenase release and elevated apoptosis. NR1, when present in the culture medium, markedly attenuated the high glucose-induced cytotoxicity in rat RCECs. Moreover, high glucose also induced a significant increase in intracellular reactive oxygen species and subsequently increased the activity of NADPH oxidase and poly-ADP (ribose) polymerase, whereas the activity of catalase decreased. The addition of NR1 to the medium significantly reduced the generation of reactive oxygen species, inhibited NADPH oxidase and poly-ADP (ribose) polymerase activities and increased catalase activity in RCECs, accompanied by a reduced cellular nitrotyrosine level. To explore the underlying mechanisms involved, the cellular redox status was monitored. Both the cellular NAD+ and NADPH levels decreased significantly in high glucose medium, which resulted in a marked decrease in the NAD+/NADH and NADPH/NADP+ ratios. High glucose stimulation also enhanced the accumulation of GSSG, maintaining the GSH/GSSG ratio lower than that in the control group with 5.5 mM glucose. When treated with NR1, the cellular NAD+, NADPH and GSH concentrations increased, and the ratios of NAD+/NADH, NADPH/NADP+ and GSH/GSSG increased, similar to the control group. These results demonstrate that NR1 attenuates high glucose-induced cell damage in RCECs. Therefore, NR1 may exert its protective effects via mechanisms that involve changes in the cellular redox state.

Astragaloside IV protects rat retinal capillary endothelial cells against high glucose-induced oxidative injury.

AIM: Diabetic retinopathy is a microvascular complication of diabetes that leads to blindness. Hyperglycemia causes oxidative stress, which is an important cause in the pathogenesis of microangiopathy. The aim of this study was to investigate the potential protective effects of astragaloside IV (AS-IV) in retinal capillary endothelial cells (RCECs) incubated with high glucose conditions. METHODS AND RESULTS: Based on rat RCECs cultured with high glucose (30 mM) in vitro, a significant increase in cell viability in rat RCECs incubated with both AS-IV and high glucose for 48 or 72 h by MTT assay. The increased viability was accompanied by decreased glucose transporter-1 expression using immunofluorescent assay. Meanwhile, AS-IV reduced intracellular hydrogen peroxide and superoxide, decreased mitochondrial reactive oxygen species in rat RCECs with high glucose by the fluorescent probes, and lowered malondialdehyde levels. In addition, AS-IV increased the activities of total superoxide dismutase, MnSOD, catalase, and glutathione peroxidase. The glutathione content also increased after AS-IV treatment. Furthermore, AS-IV reduced NADPH oxidase 4 expression by western blot method. CONCLUSION: These results suggest that the main mechanism underlying the protective effects of AS-IV in high glucose-injured RCECs may be related to its antioxidative function.

Effect of compatible herbs on the pharmacokinetics of effective components of Panax notoginseng in Fufang Xueshuantong Capsule.

Fufang Xueshuantong (FXT) is a well-known Chinese herbal formula which has been used to treat cardiovascular and ophthalmic diseases, especially diabetic retinopathy. Panax notoginseng (Burkill) F.H. Chen (PN) is the main herb of FXT, whose major bioactive constituents are ginsenosides. However, the scientific basis of the compatibility of FXT is still ambiguous. The present study investigated the scientific basis of the compatibility of FXT by comparing the pharmacokinetics of marker compounds after oral administrations of PN and FXT. A high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed for simultaneous detection of notoginsenoside R1 (NR1), ginsenoside Rg1 (GRg1), and ginsenoside Rb1 (GRb1) in rat plasma. The pharmacokinetic studies of FXT and PN were performed using the established method with the pharmacokinetic parameters being determined by non-compartmental analysis. The results showed that the pharmacokinetic parameters (maximum concentration, area under the curve (AUC0-t), clearance, and mean residence time) of NR1, GRg1, and GRb1 were significantly different after oral administration of FXT (P<0.05) compared with PN. The AUC0-t values of GRg1 and GRb1 were 1.7- and 3.4-fold greater, respectively, in FXT than in PN. The compatible herbs of FXT could prolong the retention time and increase the systemic exposure of NR1, GRg1, and GRb1 compared with PN in vivo, providing some scientific basis for the compatibility and clinical use of FXT.