Protective Effects Of Ginsenoside Rb1 Research Articles

Protective effects of ginsenoside Rb1 on H2O2-induced oxidative injury in human endothelial cell line (EA.hy926) via miR-210.

Ginsenoside Rb1 (Rb1) possesses a cardioprotective effect via mediating microRNAs (miRs), while it is unexplored whether miR-210 is regulated by Rb1 in response to oxidative stress. Human endothelial EA.hy926 cells were stimulated with H2O2 before Rb1 treatment. After transfection, cell viability, apoptosis, migration, and invasion assays were conducted. Western blot was applied to quantify protein. BCL2/adenovirus E1B 19-kDa interacting protein 3 (BNIP3) and miR-210 were analyzed with quantitative reverse transcription polymerase chain reaction. Dual luciferase activity assay was performed. Rb1 elevated viability, migration, and invasion of H2O2-treated cells. H2O2-induced apoptosis was moderated by Rb1. miR-210 was augmented in H2O2-treated cells after Rb1 stimulation. miR-210 inhibitor abolished the positive effects of Rb1. BNIP3 was negatively modulated by miR-210 and implicated in modulating viability, apoptosis, and migration and invasion. In addition, BNIP3 modulated phosphorylation of regulators. Rb1 repressed oxidative injury via elevating miR-210. miR-210 negatively mediated BNIP3, which participated in oxidative damage via regulating mammalian targets of rapamycin (mTOR) and nuclear factor-κB (NF-κB).

Ginsenoside Rb1 protects dopaminergic neurons from inflammatory injury induced by intranigral lipopolysaccharide injection.

Accumulating studies suggest that neuroinflammation characterized by microglial overactivation plays a pivotal role in the pathogenesis of Parkinson's disease. As such, inhibition of microglial overactivation might be a promising treatment strategy to delay the onset or slow the progression of Parkinson's disease. Ginsenoside Rb1, the most active ingredient of ginseng, reportedly exerts neuroprotective effects by suppressing inflammation in vitro. The present study aimed to evaluate the neuroprotective and anti-inflammatory effects of ginsenoside Rb1 in a lipopolysaccharide-induced rat Parkinson's disease model. Rats were divided into four groups. In the control group, sham-operated rats were intraperitoneally administered normal saline for 14 consecutive days. In the ginsenoside Rb1 group, ginsenoside Rb1 (20 mg/kg) was intraperitoneally injected for 14 consecutive days after sham surgery. In the lipopolysaccharide group, a single dose of lipopolysaccharide was unilaterally microinjected into the rat substantial nigra to establish the Parkinson's disease model. Lipopolysaccharide-injected rats were treated with normal saline for 14 consecutive days. In the ginsenoside Rb1 + lipopolysaccharide group, lipopolysaccharide was unilaterally microinjected into the rat substantial nigra. Subsequently, ginsenoside Rb1 was intraperitoneally injected for 14 consecutive days. To investigate the therapeutic effects of ginsenoside Rb1, behavioral tests were performed on day 15 after lipopolysaccharide injection. We found that ginsenoside Rb1 treatment remarkably reduced apomorphine-induced rotations in lipopolysaccharide-treated rats compared with the lipopolysaccharide group. To investigate the neurotoxicity of lipopolysaccharide and potential protective effect of ginsenoside Rb1, contents of dopamine and its metabolites in the striatum were measured by high-performance liquid chromatography. Compared with the lipopolysaccharide group, ginsenoside Rb1 obviously attenuated the lipopolysaccharide-induced depletion of dopamine and its metabolites in the striatum. To further explore the neuroprotective effect of ginsenoside Rb1 against lipopolysaccharide-induced neurotoxicity, immunohistochemistry and western blot assay of tyrosine hydroxylase were performed to evaluate dopaminergic neuron degeneration in the substantial nigra par compacta. The results showed that lipopolysaccharide injection caused a large loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra and a significant decrease in overall tyrosine hydroxylase expression. However, ginsenoside Rb1 noticeably reversed these changes. To investigate whether the neuroprotective effect of ginsenoside Rb1 was associated with inhibition of lipopolysaccharide-induced microglial activation, we examined expression of the microglia marker Iba-1. Our results confirmed that lipopolysaccharide injection induced a significant increase in Iba-1 expression in the substantia nigra; however, ginsenoside Rb1 effectively suppressed lipopolysaccharide-induced microglial overactivation. To elucidate the inhibitory mechanism of ginsenoside Rb1, we examined expression levels of inflammatory mediators (tumor necrosis factor-α, interleukin-1β, inducible nitric oxide synthase, and cyclooxygenase 2) and phosphorylation of nuclear factor kappa B signaling-related proteins (IκB, IKK) in the substantia nigra with enzyme-linked immunosorbent and western blot assays. Our results revealed that compared with the control group, phosphorylation and expression of inflammatory mediators IκB and IKK in the substantia nigra of lipopolysaccharide group rats were significantly increased; whereas, ginsenoside Rb1 obviously reduced lipopolysaccharide-induced changes on the lesioned side of the substantial nigra par compacta. These findings confirm that ginsenoside Rb1 can inhibit inflammation induced by lipopolysaccharide injection into the substantia nigra and protect dopaminergic neurons, which may be related to its inhibition of the nuclear factor kappa B signaling pathway. This study was approved by the Experimental Animal Ethics Committee of Shandong University of China in April 2016 (approval No. KYLL-2016-0148).

Ginsenoside Rb1 protects against spinal cord ischemia-reperfusion injury in rats by downregulating the Bax/Bcl-2 ratio and caspase-3 and p-Ask-1 levels

The aim of this study was to confirm the effects of ginsenoside Rb1 on neural cell apoptosis in the spinal cord of rats with spinal cord ischemia-reperfusion injury (SCII) and to explore its potential mechanisms. A total of 100 healthy adult Sprague-Dawley (SD) rats were randomly divided into four groups: normal control (n = 10), sham-operated (n = 10), SCII model (n = 40), and ginsenoside Rb1-treated groups (n = 40). Basso, Beattie, Bresnahan (BBB) scale was used to examine rat hindlimb locomotor function. Nissl and Tunnel staining were used to observe neural cell injury and apoptosis, respectively, in the spinal cord of rats with SCII. Immunofluorescence staining was performed to detect the expression of Bax and Bcl-2. The levels of caspase-3 and phosphorylated Ask-1 (p-Ask-1) were detected by western blotting. Ginsenoside Rb1 prevented neural cell apoptosis in the spinal cord and improved hindlimb locomotor dysfunction of rats (P < .05). Moreover, SCII-induced upregulation of caspase-3 and p-Ask-1 levels and the Bax/Bcl-2 ratio were significantly decreased by ginsenoside Rb1 (P < .05). The protective effects of ginsenoside Rb1 on neural cells in the spinal cord of rats with SCII were mediated by the ginsenoside Rb1-induced downregulation of caspase-3 and p-Ask-1 levels and the Bax/Bcl-2 ratio.

Protective Effects of Ginsenoside Rb1 against Blood-Brain Barrier Damage Induced by Human Immunodeficiency Virus-1 Tat Protein and Methamphetamine in Sprague-Dawley Rats.

Although antiretroviral therapy has helped to improve the lives of individuals infected with human immunodeficiency virus 1 (HIV-1), these patients are often still afflicted with HIV-1-associated neurocognitive disorders, which can lead to neurocognitive impairment and even dementia, and continue to hamper their quality of life. Methamphetamine abuse in HIV-1 patients poses a potential risk for HIV-associated neurocognitive disorders, because methamphetamine and HIV-1 proteins such as transactivator of transcription can synergistically damage the blood-brain barrier (BBB). In this study, we aimed to examine the effects of methamphetamine and HIV-1 Tat protein on the blood-brain barrier function and to determine whether ginsenoside Rb1 (GsRb1) plays a role in protecting the BBB. Sprague-Dawley rats were divided into four groups. The experimental groups received methamphetamine and HIV-1 Tat protein or both and the control group received saline or GsRb1 pretreatment. Oxidative stress-related factors, tight junction (TJ) proteins, blood-brain barrier permeability, and morphological changes were recorded in each group. The results showed that the group treated with Methamphetamine[Formula: see text]Tat showed a significant change at the ultrastructural level and in the levels of oxidative stress-related factors, TJ proteins, and BBB permeability, suggesting that the BBB function was severely damaged by HIV-1 Tat and methamphetamine synergistically. However, malondialdehyde levels and BBB permeability were lower and the oxidative stress-related factors superoxide dismutase and glutathione were higher in the GsRb1-treated group than in the Methamphetamine[Formula: see text]Tat-treated group, indicating that GsRb1 can protect the BBB against the toxic effects of HIV-1 Tat and methamphetamine. These results show that GsRb1 may offer a potential therapeutic option for patients with HIV-associated neurocognitive disorders or other neurodegenerative diseases.

Involvement of N-Methyl-D-Aspartic Acid Receptor and DL-α-Amino-3-Hydroxy-5- Methyl-4-Isoxazole Propionic Acid Receptor in Ginsenosides Rb1 and Rb3 against Oxygen-Glucose Deprivation-Induced Injury in Hippocampal Slices from Rat

Objective: Ginsenosides, Rb1 and Rb3, are the major protopanaxadiol components of ginseng saponin. In the present study, the influences of ginsenosides Rb1 and Rb3 on N-methyl-D-aspartic acid (NMDA) receptor or DL-α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor-mediated synaptic transmission after oxygen-glucose deprivation (OGD) were investigated. Methods: NMDA receptor population spike (NMDA-PS) or AMPA receptor-mediated population spike (AMPA-PS) was recorded in the CA1 pyramidal cell layer of rat hippocampal slices by electrophysiological techniques. Results: Under normal conditions, ginsenosides Rb3 and Rb1 depressed glutamate receptors-mediated synaptic transmission. Fourteen min of OGD resulted in a poor recovery amplitude of NMDA-PS or AMPA-PS after reoxygenation. Ginsenoside Rb3 significantly delayed the appearance of transient recovery of PS during OGD, and improved the recovery amplitudes of NMDA-PS and AMPA-PS after reoxygenation. However, the similar protective effects of ginsenoside Rb1 were observed only on NMDA-PS but not AMPA-PS. Conclusion: These results suggest that ginsenosides Rb1 and Rb3 have the different inhibitions on NMDA and AMPA receptors-mediated response, which may partially explain the different protective effects of these agents on ischemic neuronal death.

Inhibition of Autophagy is Involved in the Protective Effects of Ginsenoside Rb1 on Spinal Cord Injury.

Spinal cord injury (SCI) is a devastating neurological disorder. Autophagy is induced and plays a crucial role in SCI. Ginsenoside Rb1 (Rb1), one of the major active components extracted from Panax Ginseng CA Meyer, has exhibited neuroprotective effects in various neurodegenerative diseases. However, it remains unknown whether autophagy is involved in the neuroprotection of Rb1 on SCI. In this study, we examined the regulation of autophagy following Rb1 treatment and its involvement in the Rb1-induced neuroprotection in SCI and in vitro injury model. Firstly, we found that Rb1 treatment decreased the loss of motor neurons and promoted function recovery in the SCI model. Furthermore, we found that Rb1 treatment inhibited autophagy in neurons, and suppressed neuronal apoptosis and autophagic cell death in the SCI model. Finally, in the in vitro injury model, Rb1 treatment increased the viability of PC12 cells and suppressed apoptosis by inhibiting excessive autophagy, whereas stimulation of autophagy by rapamycin abolished the anti-apoptosis effect of Rb1. Taken together, these findings suggest that the inhibition of autophagy is involved in the neuroprotective effects of Rb1 on SCI.

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

BackgroundThe 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. MethodsLLC-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. ResultsReduction 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). ConclusionThe antiapoptotic effects of ginsenoside Rb1 on FK506-induced apoptosis were mediated by the inhibition of mitogen-activated protein kinases and caspase activation.

Impact of miR-208 and its Target Gene Nemo-Like Kinase on the Protective Effect of Ginsenoside Rb1 in Hypoxia/Ischemia Injuried Cardiomyocytes

Background/Aims: Ginsenoside Rb1 (GS-Rb1) is one of the most important active pharmacological extracts of the Traditional Chinese Medicine ginseng, with extensive evidence of its cardioprotective properties. Mir-208 has been shown to act as a biomarker of acute myocardial infarction in vivo studies including man. However the impact of miR-208 on the protective effect of GS-Rb1 in hypoxia/ischemia injured cardiomyocytes remains unclear. The current study aims to investigate the target gene of miR-208 and the impact on the protective effect of GS-Rb1 in hypoxia/ischemia (H/I) injuried cardiomyocytes. Materials and Methods: Primary cultures of neonatal rat cardiomyocytes (NRCMs) was subjected to the H/I conditions with or without GS-Rb1. Cell viability was calculated by MTT assay and confirmed by flow cytometry analysis. Mir-208 was then detected by qRT-PCR. Luciferase reporter assay was carried out to detect the target gene of Mir-208. Then the NRCMs were transfected with miR-208 mimics and inhibitors to evaluate the impact on cardioprotective properties of Rb1. Results: The miR-208 expression level was clearly upregulated in the H/I treated NRCMs accompanied by the percentage of the apoptotic cells which could be reversed by GS-Rb1 pretreatment. The nemo-like kinase (NLK) mRNA and protein expression levels were decreased in H/I group measured by RT-PCR and western blotting. Luciferase activity assay was then carried out to identify that NLK may be a direct target of mir-208. MTT assay showed that miR-208 inhibitor slightly decreased the protective effect of Rb1 on the H/I impaired NRCMs. However, results showed no statistical difference. Conclusions: These findings proved that NLK was a direct target of mir-208 and miR-208 act indirectly during Rb1 protecting H/I impaired NRCMs and further researches were needed to explore the relationship that microRNAs and other signal pathways in the protective effect of GS-Rb1 on the hypoxia/ischemia injuries in cardiomyocytes.

Involvement of Connexin40 in the Protective Effects of Ginsenoside Rb1 Against Traumatic Brain Injury.

Ginsenosides are the major active components of ginseng, which have been proven to be effective in therapies for neurodegenerative diseases. Ginsenoside Rb1 (GS-Rb1) is the most abundant among all the identified ginsenosides and has been shown to exert neuroprotective effects, although the underlying molecular mechanisms remain unclear. Connexins are a family of transmembrane proteins that form gap junctions, which are important for diffusion of cytosolic factors such as ions and second messenger signaling molecules. Previous studies have shown that a subset of connexin proteins is involved in neuroprotection. We investigated the protective effects of GS-Rb1 against traumatic brain injury (TBI) and the potential mechanism using TBI mouse model. We discovered that TBI-induced brain injury and up-regulation of connexin40 (Cx40) protein expression as early as 6h post-TBI, which was reversed by administration of GS-Rb1. In addition, we found that the protective effects of GS-Rb1 are dose and time dependent and are partially mediated through phosphorylation of ERK1/2 signaling pathway, as evidenced by the abolishment of GS-Rb1-mediated elevation of p-ERK1/2 expression and inhibition of Cx40 expressions when ERK inhibitor U0126 was used. Our study provides evidence that Cx40 is implicated in TBI-induced brain injuries, and GS-Rb1 exerts neuroprotective activity against TBI involving down-regulation of Cx40 expression.

Proteomic analysis reveals that the protective effects of ginsenoside Rb1 are associated with the actin cytoskeleton in β-amyloid-treated neuronal cells

BackgroundThe ginsenoside Rb1 (Rb1) is the most abundant compound in the root of Panax ginseng. Recent studies have shown that Rb1 has a neuroprotective effect. However, the mechanisms underlying this effect are still unknown. MethodsWe used stable isotope labeling with amino acids in cell culture, combined with quantitative mass spectrometry, to explore a potential protective mechanism of Rb1 in β-amyloid-treated neuronal cells. ResultsA total of 1,231 proteins were commonly identified from three replicate experiments. Among these, 40 proteins were significantly changed in response to Rb1 pretreatment in β-amyloid-treated neuronal cells. Analysis of the functional enrichments and protein interactions of altered proteins revealed that actin cytoskeleton proteins might be linked to the regulatory mechanisms of Rb1. The CAP1, CAPZB, TOMM40, and DSTN proteins showed potential as molecular target proteins for the functional contribution of Rb1 in Alzheimer's disease (AD). ConclusionOur proteomic data may provide new insights into the protective mechanisms of Rb1 in AD.

Protective effect of ginsenoside Rb1 on integrity of blood-brain barrier following cerebral ischemia.

Ginsenosides, the major bioactive compounds in ginseng root, have been found to have antioxidant, immunomodulatory, and anti-inflammatory activities. In the present study, we sought to investigate whether and how ginsenoside Rb1 (GS-Rb1), the most abundant ginsenoside, can protect blood-brain barrier (BBB) integrity following cerebral ischemia in middle cerebral artery occlusion (MCAO) animal model. ICR mice underwent MCAO and received GS-Rb1 by intraperitoneal injection at 3 h after reperfusion. We evaluated infarction, neurological scores, brain edema, Evans blue (EB) extravasation, and tight junction protein expression at 48 h after MCAO. We further examined whether GS-Rb1 protected BBB integrity by suppressing post-ischemic inflammation-induced activity of matrix metalloproteinase-9 (MMP-9) and nicotinamide adenine dinucleotide phosphate oxidase (NOX). First, GS-Rb1 decreased infarction and improved neurological deficits in MCAO animals. In addition, GS-Rb1 reduced EB extravasation and brain edema and preserved expression of tight junction proteins in the ischemic brain. Moreover, GS-Rb1 inhibited expression of pro-inflammatory factors including nitric oxide synthase and IL-1β, but increased expression of anti-inflammatory markers arginase 1 and IL-10 in the ischemic brain. Consistently, GS-Rb1 attenuated ischemia-induced expression and activity of MMP9. Finally, GS-Rb1 reduced NOX-4 mRNA expression and NOX activity in ischemic brain. These results suggest that GS-Rb1 protects loss of BBB integrity in ischemic stroke by suppressing neuroinflammation induction of MMP-9 and NOX4-derived free radicals, and indicate its potential for treating brain injuries, such as ischemia and stroke.

Ginsenoside Rb1 attenuates angiotensin II-induced abdominal aortic aneurysm through inactivation of the JNK and p38 signaling pathways

BackgroundAbdominal aortic aneurysm (AAA), a life-threatening vascular disease, accounts for approximately 10% of the morbidity in people over 65years old. No satisfactory approach is available to treat AAA. Ginsenosides Rb1 and Rg1 are primary ingredients of Panax notoginseng for the treatment of cardiovascular diseases, but their impact on AAA is unknown. Methods and resultsAn AAA model was established using an Ang II infusion in ApoE−/− mice. After continuous stimulation of Ang II for 28days, suprarenal aortic aneurysms developed in 77% mice and 12% mice died suddenly due to AAA rupture. Administration of ginsenoside Rb1 (20mg/kg/day), but not ginsenoside Rg1, significantly reduced the incidence and mortality of AAA. Ginsenoside Rb1 treatment dramatically suppressed Ang II-induced diameter enlargement, extracellular matrix degradation, matrix metalloproteinase (MMP) production, inflammatory cell infiltration, and vascular smooth muscle cell (VSMC) dysfunction. Mechanistic studies indicated that the protective effects of ginsenoside Rb1 were associated with the inactivation of JNK and p38 MAPK signaling pathways. A specific activator of JNK and p38, anisomycin, nearly abolished ginsenoside Rb1-driven suppression of MMP secretion by VSMCs. ConclusionsGinsenoside Rb1, as a potential anti-AAA agent, suppressed AAA through inhibiting the JNK and p38 signaling pathways.

Protective Effect of Ginsenoside Rb1 Mixing with Several Lung Flush Solutions on Pulmonary Ischemia-Reperfusion Injury

Objective: To evaluate the protective effects of ginsenoside Rb1 mixed with LPD compared to mixed with several other lung flush solutions on ischemia-reperfusion injury. Method: Three group of rabbit lungs were perfused with three kinds of mixtures of ginsenoside Rb1 with blood, Euro-Collins solution(EC) or low-potassium-dextran solution(LPD) respectively, then lung dry/wet weight ratio and malondiadehyde(MAD) were examined and histological changes were observed. Result: Lung dry/wet weight ratio of LPD and Rb1 group was higher than that of EC and Rb1 and blood and Rb1 groups, whereas MAD of LPD and Rb1 group was significantly less than that of EC and Rb1 and blood and Rb1 groups（P&lt;0.05）. Histological findings showed less damage in LPD and Rb1 group. Conclusion: Ginsenoside Rb1 mixed with LPD shows a better protective effect on pulmonary ischemia-reperfusion injury compared with other mixtures.

Protective Effect of Ginsenoside Rb1 against Intestinal Ischemia-Reperfusion Induced Acute Renal Injury in Mice

Ginsenoside Rb1 (RB1), the most clinically effective constituent of ginseng, possesses a variety of biological activities. The objectives of this study were to investigate the protective effects of RB1 and its underlying mechanism on renal injury induced by intestinal ischemia-reperfusion (IIR) in mice. RB1 was administered prior to inducing IIR achieved by occluding the superior mesenteric artery for 45 min followed by 120 min of reperfusion. All-trans-retinoic acid (ATRA) was used as an inhibitor of NF-E2-related factor-2 (Nrf2) signaling. Adult male C57BL/6J mice were randomly divided into six groups: (1) sham group, (2) IIR group, (3) RB1 group, (4) sham + ATRA group, (5) IIR + ATRA group, and (6) RB1 + ATRA group. Intestinal histology and pathological injury score were observed. Intestinal mucosal injury was also evaluated by measuring serum diamine oxidase (DAO). Renal injury induced by IIR was characterized by increased levels of histological severity score, blood urea nitrogen (BUN), serum creatinine (Scr) and neutrophil gelatinase-associated lipocalin (NGAL), which was accompanied with elevated renal TUNEL-positive cells and the Bcl-2/Bax expression ratio. RB1 significantly reduced renal injury and apoptosis as compared with IIR group, which was reversed by ATRA treatment. Immunohistochemistry and Western blot analysis demonstrated that RB1 significantly upregulated the protein expression of heme oxygenase-1 (HO-1) and Nrf2, which were attenuated by ATRA treatment. Taken together, these results suggest that the protective effects of RB1 pretreatment against renal injury induced by IIR are associated with activation of the Nrf2/ anti-oxidant response element (ARE) pathway.

Ginsenoside Rb1 Attenuates Oxygen-Glucose Deprivation-Induced Apoptosis in SH-SY5Y Cells via Protection of Mitochondria and Inhibition of AIF and Cytochrome c Release

To investigate the role of mitochondria in the protective effects of ginsenoside Rb1 on cellular apoptosis caused by oxygen-glucose deprivation, in this study, MTT assay, TUNEL staining, flow cytometry, immunocytochemistry and western blotting were used to examine the cellular viability, apoptosis, ROS level, mitochondrial membrane potential, and the distribution of apoptosis inducing factor, cytochrome c, Bax and Bcl-2 in nucleus, mitochondria and cytoplasm. We found that pretreatment with GRb1 improved the cellular viability damaged by OGD. Moreover, GRb1 inhibited apoptosis in SH-SY5Y cells induced by OGD. Further studies showed that the elevation of cellular reactive oxygen species levels and the reduction of mitochondrial membrane potential caused by OGD were both counteracted by GRb1. Additionally, GRb1 not only suppressed the translocation of apoptosis inducing factor into nucleus and cytochrome c into cytoplasm, but also inhibited the increase of Bax within mitochondria and alleviated the decrease of mitochondrial Bcl-2. Our study indicates that the protection of GRb1 on OGD-induced apoptosis in SH-SY5Y cells is associated with its protection on mitochondrial function and inhibition of release of AIF and cytochrome c.

Protective effect of ginsenoside Rb1 on ultraviolet B-induced damage and its possible mechanisms

Objective To estimate the effect of ginsenoside Rb1 on the production and clearance of cyclobutane pyrimidine dimer (CPD) as well as on the expression of two nucleotide excision repair-associated proteins,xeroderma pigmentosum group C (XPC) and excision repair cross-complementing group 1 (ERCC1),by ultraviolet B (UVB)-irradiated murine epidermal cells and human HaCaT keratinocytes.Methods Totally,42 BALB/c mice were shaved on the back and divided into four groups: untreated group (n =6),UVB group irradiated with UVB only (n =12),low-dose and high-dose Rb1 group (both n =12) treated with Rb1 of 0.5 g/L and 2g/L (100 μl/cm2) respectively two hours before UVB irradiation.The dose of UVB in the animal experiment was 180 mJ/cm2.Half of the mice in each group were killed at 0.5 and 16 hours respectively after the irradiation,then,the back skin was resected and subjected to the determination of CPD levels in the epidermis by immunohistochemical SP method.Some cultured HaCaT cells were divided into several groups to be treated with different concentrations (5,20,50 mg/L) of Rb1 before or after different doses (15 and 30 mnJ/cm2) of UVB irradiation,and cells were collected at 0.5 and 12 hours after the irradiation.Subsequently,genomic DNA was extracted and CPD was detected by dot blot hybridization.Some HaCaT cells were cultured with or without the presence of Rb1 (50 mg/L) and irradiated with UVB (30 mJ/cm2),then,the cells were collected immediately or at 0.5,2,4 and 12 hours after the irradiation,and total protein was extracted and subjected to immunoblot analysis for the quantification of XPC and ERCC1 proteins.Results There was a high level of CPD in the epidermis of mice at 0.5 hour after the irradiation,with no significant differences between these groups (P ＞ 0.05).The number of CPD-positive cells per high power field (× 400) in the murine epidermis at 16 hours was statistically lower in the low-and high-dose Rb1 group than in the UVB group (32.1 ± 8.5 and 14.6 ± 4.1 vs.67.3 ± 11.2,both P ＜0.01).The CPD level in HaCaT cells was similar between these groups at 0.5 hour after UVB irradiation,but was markedly decreased at 12 hours in Rb1-treated groups.After UVB irradiation,the protein expressions of XPC and ERCC1 decreased with time in untreated HaCaT cells but increased with time in Rb1 (50 mg/L)-treated HaCaT cells.In detail,the XPC/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein ratio in untreated HaCaT cells was 0.68 ± 0.11 immediately after the irradiation,significantly higher than that at 0.5 hour (0.47 ± 0.09,P＜0.05),2 hours (0.45 ± 0.08,P＜0.05),4 hours (0.37 ± 0.06,P＜0.01),and 12 hours (0.18 ± 0.03,P ＜0.01),and that in Rb1-treated HaCaT cells was 0.56 ± 0.07 immediately after the irradiation,compared to 0.48 ± 0.14 at 0.5 hour (P＞ 0.05),0.68 ± 0.15 at 2 hours (P＞ 0.05),0.97 ± 0.20 at 4 hours (P＜0.01),and 0.79 ± 0.12 at 12 hours (P ＜0.05).The ERCC1/GAPDH protein ratio in untreated HaCaT cells was 0.28 ± 0.03 immediately after the irradiation,higher than that at 0.5 hour (0.25 ± 0.03,P ＞ 0.05),2 hours (0.21 ± 0.02,P＜0.05),4 hours (0.14 ± 0.02,P＜0.01) and 12 hours (0.11 ± 0.01,P＜0.01),and that in Rb1-treated HaCaT cells was 0.27 ± 0.04 immediately after the irradiation,compared to 0.24 ± 0.04 at 0.5 hour (P＞ 0.05),0.29 ± 0.05 at 2 hours (P＞ 0.05),0.35 ± 0.05 at 4 hours (P＜0.05),0.39 ± 0.05 at 12 hours (P ＜0.01).Conclusions Ginsenoside Rb1 shows no obvious effect on the UVB-induced production of CPD,but markedly accelerates the clearance of CPD,which may be partly associated with the upregulation of XPC and ERCC1 protein expression. Key words: GINSENOSIDE; Ultraviolet rays; Cyclobutane pyrimidine dimers; Keratinocytes

Protective Effect of Ginsenoside Rb1 Against Lung Injury Induced by Intestinal Ischemia-Reperfusion in Rats

Intestinal ischemia-reperfusion (I/R) is a critical event in the pathogenesis of multiple organ dysfunction syndromes (MODS). The lungs are some of the most vulnerable organs that are impacted by intestinal I/R. The aim of this study is to investigate whether ginsenoside Rb1 can ameliorate remote lung injury induced by intestinal I/R. Adult male Wistar rats were randomly divided into four groups: (1) a control, sham-operated group (sham group); (2) an intestinal I/R group subjected to 1 h intestinal ischemia and 2 h reperfusion (I/R group); (3) a group treated with 20 mg/kg ginsenoside Rb1 before reperfusion (Rb1-20 group); and (4) a group treated with 40 mg/kg ginsenoside Rb1 before reperfusion (Rb1-40 group). Intestinal and lung histology was observed. The malondialdehyde (MDA) levels in intestinal tissues were measured. Myeloperoxidase (MPO), TNF-α, MDA levels, wet/dry weight ratio and immunohistochemical expression of intracellular adhesion molecule-1 (ICAM-1) in lung tissues were assayed. In addition, a western blot of lung NF-kB was performed. Results indicated that intestinal I/R induced intestinal and lung injury, which was characterized by increase of MDA levels and pathological scores in intestinal tissues and MPO, TNF-α , MDA levels, wet/dry weight ratio and ICAM-1, NF-kB expression in the lung tissues. Ginsenoside Rb1 (20, 40 mg/kg) ameliorated intestinal and lung injury, decreased MPO, TNF-α, MDA levels, wet/dry weight ratio, ICAM-1 and NF-kB expression in lung tissues. In conclusion, ginsenoside Rb1 ameliorated the lung injuries by decreasing the NF-kB activation-induced inflammatory response.

Ginsenoside Rb1 Preconditioning Enhances eNOS Expression and Attenuates Myocardial Ischemia/Reperfusion Injury in Diabetic Rats

Diabetes mellitus is associated with decreased NO bioavailability in the myocardium. Ginsenoside Rb1 has been shown to confer cardioprotection against ischemia reperfusion injury. The aim of this study was to investigate whether Ginsenoside Rb1 exerts cardioprotective effects during myocardial ischemia-reperfusion in diabetic rats and whether this effect is related to increase the production of NO via enhancing eNOS expression in the myocardium. The myocardial I/R injury were induced by occluding the left anterior descending artery for 30 min followed by 120 min reperfusion. An eNOS inhibitor L-NAME or Rb1 were respectively administered 25 min or 10 min before inducing ischemia. Ginsenoside Rb1 preconditioning reduced myocardial infarct size when compared with I/R group. Ginsenoside Rb1 induced myocardial protection was accompanied with increased eNOS expression and NO concentration and reduced plasma CK and LDH (P < 0.05). Moreover, the myocardial oxidative stress and tissue histological damage was attenuated by Ginsenoside Rb1 (P < 0.05). L-NAME abolished the protective effects of Ginsenoside Rb1. It is concluded that Ginsenoside Rb1 protects against myocardium ischemia/reperfusion injury in diabetic rat by enhancing the expression of eNOS and increasing the content of NO as well as inhibiting oxidative stress.

Protective effect of ginsenoside Rb1 against myocardial ischemia/reperfusion injury in streptozotocin-induced diabetic rats

The objective of the current study is to investigate whether ginsenoside Rb1, a major pharmacological extract of ginseng that could attenuate myocardial ischemia reperfusion (MI/R) injury in non-diabetic myocardium, can attenuate MI/R injury in diabetes that are more vulnerable to ischemic insult. Rats were divided into seven groups: (i) diabetic sham, (ii) diabetic, (iii) normal, (iv) diabetic + ginsenoside Rb1, (v) diabetic + wortmannin, (vi) diabetic + wortmannin + ginsenoside Rb1, (vii) diabetic sham + wortmannin. Ginsenoside Rb1 and/or wortmannin were administered prior to inducing MI/R (30 min of coronary artery occlusion followed by 120 min reperfusion). At the end of the experiment, postischemic myocardial infarct size was significantly higher in the diabetic untreated group as compared to normal (P < 0.05), accompanied with increased myocardial apoptosis, elevated plasma CK-MB and LDH release and reduced blood pressure. Ginsenoside Rb1 reduced infarct size, cardiomyocyte apoptosis and caspase-3 activity compared to the diabetic group. The cardioprotective effects of ginsenoside Rb1 were cancelled by wortmannin. Ginsenoside Rb1 significantly upregulated phosphorylated Akt expression, which was attenuated by wortmannin. Ginsenoside Rb1 exerts cardioprotective effects against MI/R injury in diabetic rats, which is partly through activation of phosphatidylinositol 3-kinase (PI3 K)/Akt pathway. Thus this study shows a novel pharmacological preconditioning with ginsenoside Rb1 in the diabetic myocardium.

Ginsenoside rb1 and rg3 attenuate glucocorticoid-induced neurotoxicity.

Glucocorticoid (GC) hormones, increased in response to stress, can cause neuronal loss. We tested the effect of GC hormone on cell viability of neural SHSY-5Y cells and protective effects of ginsenoside Rb1 and Rg3 on the action of GC. We treated SHSY-5Y cells with increasing concentrations of synthetic GC dexamethasone (DEX; 10, 25, 50, and 100 nM) for 24 and 48 h, and then determined cell viability by using MTT assay. We then treated SHSY-5Y cells with DEX (100 nM) with or without the ginsenosides to examine their preventive effects on the cytotoxicity. To explore the underlying molecular mechanisms, we measured mRNA expression of bax and bcl-2 by using reverse transcriptase real-time PCR. SHSY-5Y cells treated with DEX significantly reduced cell viability as compared with control cells. In the presence of Rb1 or Rg3, DEX-induced cytotoxicity was effectively blocked. DEX considerably increased pro-apoptotic bax mRNA expression as compared with control cells. However, Rb1 and Rg3 completely blocked DEX-mediated up-regulation of bax expression. DEX significantly increased neuronal death in organotypic hippocampal slice cultures of rat brain with enhanced generation of ROS, which was effectively inhibited by ginsenoside Rb1 and Rg3. This suggests a potential role of the ginsenosides to target GC action in the brain.