Effects of ginsenoside Rb1 on oxidative stress injury in rat spinal cords by regulating the eNOS/Nrf2/HO-1 signaling pathway

Astragalus polysaccharides attenuate rat aortic endothelial senescence via regulation of the SIRT-1/p53 signaling pathway

BACKGROUND

Astragalus polysaccharides (APS) have been verified to have antioxidative and antiaging activities in the mouse liver and brain. However, the effect of APS on aortic endothelial senescence in old rats and its underlying mechanism are currently unclear. Here, we aimed to elucidate the effects of APS on rat aortic endothelial oxidative stress and senescence in vitro and in vivo and investigate the potential molecular targets.

METHODS

Twenty-month-old natural aging male rats were treated with APS (200 mg/kg, 400 mg/kg, 800 mg/kg daily) for 3 months. Serum parameters were tested using corresponding assay kits. Aortic morphology was observed by staining with hematoxylin and eosin (H&E) and Verhoeff Van Gieson (VVG). Aging-related protein levels were evaluated using immunofluorescence and western blot analysis. Primary rat aortic endothelial cells (RAECs) were isolated by tissue explant method. RAEC mitochondrial function was evaluated by the mitochondrial membrane potential (MMP) measured with the fluorescent lipophilic cationic dye JC‑1. Intracellular total antioxidant capacity (T-AOC) was detected by a commercial kit. Cellular senescence was assessed using senescence-associated-β-galactosidase (SA-β-Gal) staining.

RESULTS

Treatment of APS for three months was found to lessen aortic wall thickness, renovate vascular elastic tissue, improve vascular endothelial function, and reduce oxidative stress levels in 20-month-old rats. Primary mechanism analysis showed that APS treatment enhanced Sirtuin 1 (SIRT-1) protein expression and decreased the levels of the aging marker proteins p53, p21 and p16 in rat aortic tissue. Furthermore, APS abated hydrogen peroxide (H2O2)-induced cell senescence and restored H2O2-induced impairment of the MMP and T-AOC in RAECs. Similarly, APS increased SIRT-1 and decreased p53, p21 and p16 protein levels in senescent RAECs isolated from old rats. Knockdown of SIRT-1 diminished the protective effect of APS against H2O2-induced RAEC senescence and T-AOC loss, increased the levels of the downstream proteins p53 and p21, and abolished the inhibitory effect of APS on the expression of these proteins in RAECs.

CONCLUSION

APS may reduce rat aortic endothelial oxidative stress and senescence via the SIRT-1/p53 signaling pathway.

Ginsenoside Rb1 protects human vascular smooth muscle cells against resistin-induced oxidative stress and dysfunction

Resistin has been shown to play a key role in inducing vascular smooth muscle cells (VSMCs) malfunction in the atherosclerosis progression. Ginsenoside Rb1 is the main component of ginseng, which has been used for thousands of years and has been reported to have a powerful vascular protective effect. The aim of this study was to explore the protective effect of Rb1 on VSMCs dysfunction induced by resistin. In the presence or absence of Rb1, human coronary artery smooth muscle cells (HCASMC) were treated at different time points with or without 40 ng/ml resistin and acetylated low-density lipoprotein (acetylated LDL). Cell migration and proliferation were analyzed using wound healing test and CellTiter Aqueous Cell Proliferation Assay (MTS) test, respectively. Intracellular reactive oxygen species (ROS) (H2DCFDA as a dye probe) and superoxide dismutase (SOD) activities were measured by a microplate reader and the differences between groups were compared. Rb1 significantly reduced resistin-induced HCASMC proliferation. Resistin increased HCASMC migration time-dependently. At 20 µM, Rb1 could significantly reduce HCASMC migration. Resistin and Act-LDL increased ROS production to a similar level in HCASMCs, while Rb1 pretreated group reversed the effects of resistin and acetyl-LDL. Besides, the mitochondrial SOD activity was significantly reduced by resistin but was restored when pretreated with Rb1. We confirmed the protection of Rb1 on HCASMC and suggested that the mechanisms involved might be related to the reduction of ROS generation and increased activity of SOD. Our study clarified the potential clinical applications of Rb1 in the control of resistin-related vascular injury and in the treatment of cardiovascular disease.

Ginsenoside Rb1 improves energy metabolism after spinal cord injury

Mitochondrial damage caused by oxidative stress and energy deficiency induced by focal ischemia and hypoxia are important factors that aggravate diseases. Studies have shown that ginsenoside Rb1 has neurotrophic and neuroprotective effects. However, whether it influences energy metabolism after spinal cord injury remains unclear. In this study, we treated mouse and cell models of spinal cord injury with ginsenoside Rb1. We found that ginsenoside Rb1 remarkably inhibited neuronal oxidative stress, protected mitochondria, promoted neuronal metabolic reprogramming, increased glycolytic activity and ATP production, and promoted the survival of motor neurons in the anterior horn and the recovery of motor function in the hind limb. Because sirtuin 3 regulates glycolysis and oxidative stress, mouse and cell models of spinal cord injury were treated with the sirtuin 3 inhibitor 3-TYP. When Sirt3 expression was suppressed, we found that the therapeutic effects of ginsenoside Rb1 on spinal cord injury were remarkably inhibited. Therefore, ginsenoside Rb1 is considered a potential drug for the treatment of spinal cord injury, and its therapeutic effects are closely related to sirtuin 3.

Mechanisms of ginsenosides exert neuroprotective effects on spinal cord injury: A promising traditional Chinese medicine

Spinal cord injury (SCI) is a devastating disorder of the central nervous system (CNS). It is mainly caused by trauma and reduces the quality of life of the affected individual. Ginsenosides are safe and effective traditional Chinese medicines (TCMs), and their efficacy against SCI is being increasingly researched in many countries, especially in China and Korea. This systematic review evaluated the neuroprotective effects of ginsenosides in SCI and elucidated their properties.

Korean Red Ginseng Ameliorates Allergic Asthma through Reduction of Lung Inflammation and Oxidation

Six-year-old red ginseng, which is processed from the whole ginseng root via steaming and drying, has been shown to have preventive effects such as antioxidative, anti-inflammatory, and immunomodulatory. In this study, we evaluated the therapeutic effects of Korean red ginseng (KRG) against ovalbumin (OVA)-induced allergic asthma and the underlying mechanisms involved. We injected 20 µg of OVA on days 0 and 14, and mice were challenged with aerosolized OVA via a nebulizer for 1 h on days 21, 22, and 23. KRG was administered at 100 and 300 mg/kg from days 18 to 23. The KRG-treated mice showed significant reductions in their airway hyperresponsiveness, production of reactive oxygen species (ROS), and the number of inflammatory cells compared with the OVA-treated mice. The levels of type 2 cytokines in the bronchoalveolar lavage fluid and expression of OVA-specific immunoglobulin E in the serum, which were elevated in the OVA group, were reduced in the KRG-treated groups. The pro-inflammatory factors, inducible nitric oxide synthase and nuclear factor kappa-light-chain-enhancer of activated B cells, were downregulated by the KRG administration in a dose-dependent manner. KRG effectively suppressed the inflammatory response by inhibiting ROS production. Our results suggest that KRG may have the potential to alleviate asthma.

Neuroprotective Mechanisms of Ginsenoside Rb1 in Central Nervous System Diseases

Panax ginseng and Panax notoginseng, two well-known herbs with enormous medical value in Asian countries, have a long usage history in China for the therapy of some diseases, such as stroke. Ginsenoside Rb1 is one of most important active ingredients in Panax ginseng and Panax notoginseng. In the last two decades, more attention has focused on ginsenoside Rb1 as an antioxidative, anti-apoptotic and anti-inflammatory agent that can protect the nervous system. In the review, we summarize the neuroprotective roles of ginsenoside Rb1 and its potential mechanisms in central nervous system diseases (CNSDs), including neurodegenerative diseases, cerebral ischemia injury, depression and spinal cord injury. In conclusion, ginsenoside Rb1 has a potential neuroprotection due to its inhibition of oxidative stress, apoptosis, neuroinflammation and autophagy in CNSDs and may be a promising candidate agent for clinical therapy of CNSDs in the future.

Recent Advances in the Role of Nuclear Factor Erythroid-2-Related Factor 2 in Spinal Cord Injury: Regulatory Mechanisms and Therapeutic Options

Nuclear factor erythroid-2-related factor 2 (Nrf2) is a pleiotropic transcription factor, and it has been documented that it can induce defense mechanisms both oxidative stress and inflammatory injury. At present, more and more evidences show that the Nrf2 signaling pathway is a key pharmacological target for the treatment of spinal cord injury (SCI), and activating the Nrf2 signaling pathway can effectively treat the inflammatory injury and oxidative stress after SCI. This article firstly introduces the biological studies of the Nrf2 pathway. Meanwhile, it is more powerful to explain that activating the Nrf2 signaling pathway can effectively treat SCI by deeply exploring the relationship between Nrf2 and oxidative stress, inflammatory injury, and SCI. In addition, several potential drugs for the treatment of SCI by promoting Nrf2 activation and Nrf2-dependent gene expression are reviewed. And some other treatment strategies of SCI by modulating the Nrf2 pathway are also summarized. It will provide new ideas and directions for the treatment of SCI.

Ginsenosides Rb1 Attenuates Chronic Social Defeat Stress-Induced Depressive Behavior via Regulation of SIRT1-NLRP3/Nrf2 Pathways

Ginsenoside Rb1, a diol-type ginseng saponin, has various positive effects on the central nervous system. This study aimed to evaluate the antidepressant effects of Rb1 on chronic social defeat stress (CSDS) induced behavioral deficits and the exact neural cascades linked with inflammatory processes. The results of behavioral tests such as social interaction, tail suspension, and forced swimming revealed that oral treatment of Rb1 (35 and 70 mg/kg) alleviates depression-like behavior. Rb1 treatment increased antioxidant enzyme activity (SOD and CAT) and reduced lipid peroxidation (LPO) content in the hippocampus. Rb1 also suppressed the production of inflammatory cytokines (TNF-α, IL-18, and IL-1β) as well as microglial activation (Iba1) in response to CSDS. Moreover, Rb1 administration considerably reduced the protein expression of NLRP3 (inflammasome) and promoted the protein expressions of Nrf2, HO-1 and Sirtuin1(SIRT1) activation in the hippocampus. Our findings showed that Rb1 effectively restores the depressive-like behavior in CSDS-induced model mice, mediated in part by the normalization of oxidative stress levels. The suppression of neuroinflammation is mediated by the regulation of SIRT1-NLRP3/Nrf2 pathways. Our results asserted that the Rb1 is a novel therapeutic candidate for treating depression.

Oxidative Stress and Ginsenosides: An Update on the Molecular Mechanisms

Ginsenosides are a class of active components extracted from ginseng plants (such as Panax ginseng, Panax quinquefolium, and Panax notoginseng). Ginsenosides have significant protective effects on the nervous system, cardiovascular system, and immune system, so they have been widely used in the treatment of related diseases. Entry of a variety of endogenous or exogenous harmful substances into the body can lead to an imbalance between the antioxidant defense system and reactive oxygen species, thus producing toxic effects on a variety of tissues and cells. In addition, oxidative stress can alter multiple signaling pathways, including the Keap1/Nrf2/ARE, PI3K/AKT, Wnt/β-catenin, and NF-κB pathways. With the deepening of research in this field, various ginsenoside monomers have been reported to exert antioxidant effects through multiple signaling pathways and thus have good application prospects. This article summarized the research advancements regarding the antioxidative effects and related mechanisms of ginsenosides, providing a theoretical basis for experimental research on and clinical treatment with ginsenosides.

Future Perspectives in Oxidative Stress in Trisomy 13 and 18 Evaluation

Autosomal aneuploidies are the most frequently occurring congenital abnormalities and are related to many metabolic disorders, hormonal dysfunctions, neurotransmitter abnormalities, and intellectual disabilities. Trisomies are generated by an error of chromosomal segregation during cell division. Accumulating evidence has shown that deregulated gene expression resulting from the triplication of chromosomes 13 and 18 is associated with many disturbed cellular processes. Moreover, a disturbed oxidative stress status may be implicated in the occurrence of fetal malformations. Therefore, a literature review was undertaken to provide novel insights into the evaluation of trisomy 13 (T13) and 18 (T18) pathogeneses, with a particular concern on the oxidative stress. Corresponding to the limited literature data focused on factors leading to T13 and T18 phenotype occurrence, the importance of oxidative stress evaluation in T13 and T18 could enable the determination of subsequent disturbed metabolic pathways, highlighting the related role of mitochondrial dysfunction or epigenetics. This review illustrates up-to-date T13 and T18 research and discusses the strengths, limitations, and possible directions for future studies. The progressive unification of trisomy-related research protocols might provide potential medical targets in the future along with the implementation of the foundation of modern prenatal medicine.

The Effects of Ginsenosides on the Nrf2 Signaling Pathway

Nuclear factor erythroid-2 related factor 2 (Nrf2) is a major signaling pathway for the maintenance of homeostasis and redox balance. This pathway also plays a significant role in proteostasis, xenobiotic/drug metabolism, apoptosis, and lipid and carbohydrate metabolism. Conversely, the Nrf2 signaling pathway is impaired in several pathological conditions including cancer. Although various drugs have been developed to target the Nrf2 pathway, plant-derived chemicals than can potentially impact this pathway and are particularly attractive due to their minimal side effects. Ginsenosides are active components of ginseng and have been shown to exert pharmacological effects including antioxidant, anti-inflammatory, antitumor, antidiabetes, neuroprotective, and hepatoprotective activities. In this article, we have reviewed the effects of ginsenosides on Nrf2 signaling pathway.

Neutrophil Gelatinase-Associated Lipocalin 2 Accelerates Hypoxia-Induced Endothelial Cell Injury via eNOS/NRF2 Signalling

Objective

Neutrophil gelatinase-associated lipocalin (NGAL), a lipocalin, is implicated in many cardiovascular diseases (CVD). The effect of NGAL on endothelial cells (ECs), particularly on ECs injured because of hypoxia, is unclear. In this study, we aim to explore the effect of NGAL in an EC injury in response to hypoxia.

Materials and Methods

In this experimental study, we isolated and cultured mouse heart ECs (MHECs). The EC injury model was established by exposure of the ECs to hypoxia for 24 hours. The ECs were treated with NGAL (30, 60, 120, 250 and 500 ng/ml). Cell inflammation and oxidative stress were detected by corresponding assays. Apoptotic cells were stained by the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay.

Results

NGAL increased the inflammatory response at the baseline level and further augmented the hypoxia-induced inflammation response. Reactive oxygen species (ROS) levels increased upon NGAL treatment, which caused antioxidase/oxidase imbalance. NGAL also exaggerated hypoxia-induced oxidative stress. The cell apoptosis rate also increased in both the NGAL-treated normoxic and hypoxic conditions. NGAL also reduced endothelial nitric oxide synthase (eNOS)-nitric oxide (NO) signalling, thus decreasing the expression and nuclear translocation of nuclear factor erythroid-2-related factor 2 (NRF2), which was confirmed by overexpression of NRF2.

Conclusion

NGAL exaggerates EC injury in both normoxic and hypoxic conditions by inhibiting the eNOS-NRF2 pathway.

Cellular Senescence and Vitamin D Deficiency Play a Role in the Pathogenesis of Obesity-Associated Subclinical Atherosclerosis: Study of the Potential Protective Role of Vitamin D Supplementation

The exact link between obesity, vitamin D deficiency, and their relation to cellular senescence in the pathogenesis of subclinical atherosclerosis is still under debate. Therefore, the current study aims to verify the possible role of vitamin D deficiency and cellular senescence in the pathogenesis of obesity-related subclinical atherosclerosis. Moreover, it aims to investigate the possible protective role of vitamin D supplementation. Fifty-seven male albino rats were enrolled in the study and classified into four groups: negative (10) and positive control groups (10), an obese model group (24), and a vitamin-D-supplemented obese group (13). Aortic tissue samples and fasting blood samples were collected. The following biochemical investigations were performed: serum cholesterol, triglycerides, HDL-C, LDL-C, ALT, AST, CPK, CK-MB, and hs-cTnt. HOMA-IR was calculated. Moreover, serum SMP-30, 25 (OH)Vitamin D3, and eNOS were determined by the ELISA technique. Aortic gene expression of eNOS, SMP-30, and P53 was estimated by real-time qRT-PCR. Serum 25(OH) D3 and SMP-30 were lower in the obese group. In addition, the obese group showed higher serum lipid profile, HOMA-IR, eNOS, ALT, AST, CPK, CK-MB, and hs-cTnt than the control groups, while decreased levels were found in the vitamin-D-treated obese group. Gene expression of eNOS and SMP-30 were in accordance with their serum levels. A positive correlation was found between vitamin D level and SMP-30. In conclusion, obesity is associated with vitamin D deficiency and enhanced cellular senescence. They could play a role in the pathogenesis of obesity-associated subclinical atherosclerosis and endothelial dysfunction. Vitamin D supplements could play a protective role against such obesity-related comorbidity.

Curcumin promotes the survival of ischemic random skin flaps via autophagy

Random skin flaps have been widely applied in reconstructive and plastic surgery; however, necrosis usually happens due to insufficient blood supply in the ischemic area of flaps. Curcumin (CUR) is a primary bioactive compound of turmeric (Curcuma longa, L.), which has been proven to be effective on anticancer, decreasing oxidative stress and apoptosis through activating autophagy, and promoting angiogenesis in ischemic tissue. Therefore, the potential therapeutic effect of CUR on promoting survival of ischemic random skin flaps and its underlying mechanism associated with autophagy were investigated. After establishment of dorsal random skin flaps, sixty mice were randomly divided into three groups: Control, CUR or CUR+3-methyladenine (3-MA, an autophagy inhibitor). The results showed that CUR increased the viability area and blood flow as well as relieved the edema of skin flaps through promoting angiogenesis, decreasing oxidative stress, and inhibiting apoptosis of the ischemic area. Further study confirmed that CUR activated autophagy in the random skin flaps, and 3-MA effectively reversed the effect on viability, neovascularization, oxidative stress and apoptosis, suggesting autophagy played a vital role in these CUR's protective effect on random skin flaps. Moreover, this CUR-induced autophagy should be mediated through downregulating the PI3K/AKT/mTOR signaling pathway. Together with secondary response of increased angiogenesis, reduced oxidative stress and apoptosis, CUR effectively improved survival of random skin flaps in vivo. To sum up, our research showed the great potential of CUR using as a promising flap protective therapy for random skin flap survival and regeneration.

Hormetic Effects of Bioactive Compounds from Foods, Beverages, and Food Dressing: The Potential Role in Spinal Cord Injury

Spinal cord injury (SCI) is a damage or trauma to the spinal cord resulting in a total or partial loss of motor and sensory function. SCI is characterized by a disequilibrium between the production of reactive oxygen species and the levels of antioxidant defences, causing oxidative stress and neuroinflammation. This review is aimed at highlighting the hormetic effects of some compounds from foods, beverages, and food dressing that are able to reduce oxidative stress in patients with SCI. Although curcumin, ginseng, and green tea have been proposed for SCI management, low levels of antioxidant vitamins have been reported in individuals with SCI. Mediterranean diet includes food rich in vitamins and antioxidants. Moreover, food dressing, including spices, herbs, and extra virgin olive oil (EVOO), contains multiple components with hormetic effects. The latter involves the activation of the nuclear factor erythroid-derived 2, consequently increasing the antioxidant enzymes and decreasing inflammation. Furthermore, EVOO improves the bioavailability of carotenoids and could be a delivery system for bioactive compounds. In conclusion, Mediterranean dressing in addition to plant foods can have an important effect on redox balance in individuals with SCI.

High serum superoxide dismutase activity improves radiation-related quality of life in patients with esophageal squamous cell carcinoma

OBJECTIVES

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors in China. Intensity-modulated radiation therapy and volume-modulated arc therapy have become the main treatments for esophageal carcinoma; however, side effects caused by radiotherapy greatly impact the quality of life in these patients. This study aimed to explore the impact of serum superoxide dismutase (SOD) levels on the prognosis of patients with ESCC undergoing radiotherapy.

METHODS

Patients aged between 18 and 80 years with lower-middle ESCC who underwent radiotherapy were eligible for this assessment. Adverse events, responses, treatment outcomes, and overall survival (OS) were assessed. Between 2012 and 2014, 195 patients were enrolled, of which 65 were assigned to the low- and high-SOD groups based on their serum SOD values.

RESULTS

The baseline characteristics were similar between the two groups, except for the T staging. Adverse events in the low-SOD group were significantly higher than those in the high-SOD group (radiation esophagitis, p=0.007; radiation pneumonitis, p=0.032; leukopenia, p=0.023; thrombocytopenia, p=0.037; anemia, p=0.041). There were no significant differences in response, treatment outcomes, or OS.

CONCLUSION

In conclusion, high serum SOD activity improved post-radiotherapy quality of life but did not impact the prognosis of patients with ESCC. To the best of our knowledge, this study is the first to report that serum SOD activity is associated with radiation-induced toxicity and moderately increased radiotherapeutic response in patients with ESCC undergoing radiotherapy.

Beneficial Effects of Naringenin in Cigarette Smoke-Induced Damage to the Lung Based on Bioinformatic Prediction and In Vitro Analysis

Naringenin is found mainly in citrus fruits, and is thought to be beneficial in the prevention and control of lung diseases. This study aims to investigate the mechanisms of naringenin against the damage in the lung caused by cigarette smoke. A system bioinformatic approach was proposed to predict the mechanisms of naringenin for protecting lung health. Then, we validated this prediction in BEAS-2B cells treated with cigarette smoke extract (CSE). System bioinformatic analysis indicated that naringenin exhibits protective effects on lung through the inhibition of inflammation and suppression of oxidative stress based on a multi-pathways network, mainly including oxidative stress pathway, Nrf2 pathway, Lung fibrosis pathway, IL-3 signaling pathway, and Aryl hydrocarbon receptor pathway. The in vitro results showed that naringenin significantly attenuated CSE-induced up-regulation of IL-8 and TNF-α. CSE stimulation increased the mRNA expressions of Nrf2, HO-1, and NQO1; the levels of total protein and nuclear protein of Nrf2; and the activity of SOD on days 2 and 4; but decreased these indexes on day 6. Naringenin can balance the antioxidant system by regulating Nrf2 and its downstream genes, preliminarily validating that Nrf2 pathway is involved in the protection offered by naringenin against cigarette smoke-induced damage to the lung. It suggests that dietary naringenin shows possible potential use in the management of lung health.

Ginsenoside Re Mitigates 6-Hydroxydopamine-Induced Oxidative Stress through Upregulation of GPX4

Ginsenosides are active components found abundantly in ginseng which has been used as a medicinal herb to modify disease status for thousands of years. However, the pharmacological activity of ginsenoside Re in the neuronal system remains to be elucidated. Neuroprotective activity of ginsenoside Re was investigated in SH-SY5Y cells exposed to 6-hydroxydopamine (6-OHDA) to induce cellular injury. Ginsenoside Re significantly inhibited 6-OHDA-triggered cellular damage as judged by analysis of tetrazolium dye reduction and lactose dehydrogenase release. In addition, ginsenoside Re induced the expression of the antioxidant protein glutathione peroxidase 4 (GPX4) but not catalase, glutathione peroxidase 1, glutathione reductase, or superoxide dismutase-1. Furthermore, upregulation of GPX4 by ginsenoside Re was mediated by phosphoinositide 3-kinase and extracellular signal-regulated kinase but not by p38 mitogen-activated protein kinase or c-Jun N-terminal kinase. Ginsenoside Re also suppressed 6-OHDA-triggered cellular accumulation of reactive oxygen species and peroxidation of membrane lipids. The GPX4 inhibitor (1S,3R)-RSL3 reversed ginsenoside Re-mediated inhibition of cellular damage in SH-SY5Y cells exposed to 6-OHDA, indicating that the neuronal activity of ginsenoside Re is due to upregulation of GPX4. These findings suggest that ginsenoside Re-dependent upregulation of GPX4 reduces oxidative stress and thereby alleviates 6-OHDA-induced neuronal damage.

Effects of ginsenoside Rb1 on spinal cord ischemia-reperfusion injury in rats

Background

The aim of this study was to evaluate the effects of different doses of ginsenoside Rb1 (GRb1) pretreatment on spinal cord ischemia-reperfusion (SCII) in rats and explore the potential mechanisms about the expression of survivin protein after the intervention.

Methods

A total of 90 healthy adult Sprague-Dawley (SD) rats were randomly divided into six groups: sham-operated (n = 15), SCII model (n = 15), and GRb1-treated groups (n = 60). The GRb1-treated group was divided into four subgroups: 10 mg/kg, 20 mg/kg, 40 mg/kg, and 80 mg/kg (n = 15). The corresponding dose of GRb1 was injected intraperitoneally 30 min before operation and every day after operation. Forty-eight hours after model establishment, the neurological function of hind limbs was measured with Basso, Beattie, and Bresnahan (BBB) scale. The superoxide dismutase (SOD) and malondialdehyde (MDA) levels in serum and spinal cord tissue were detected respectively. The expression of survivin protein was observed by immunofluorescence staining. HE and TUNEL staining were used to observe neural cell injury and apoptosis, respectively, in the spinal cord of rats with SCII.

Results

The intervention of different doses of GRb1 could increase SOD activity and decrease MDA content in serum and spinal cord tissue, increase survivin protein expression, and decrease neuronal apoptosis. It was dose-dependent, but there was no significant change between 40 mg/kg and 80 mg/kg.

Conclusions

GRb1 could reduce the cell apoptosis induced by SCII through inhibiting oxidative stress. It can also inhibit apoptosis by promoting the expression of Survivin protein. Ginsenoside Rb1 had a dose-dependent protective effect on SCII in the dose range of 10 mg/kg–40 mg/kg.

Engagement of MicroRNA-155 in Exaggerated Oxidative Stress Signal and TRPA1 in the Dorsal Horn of the Spinal Cord and Neuropathic Pain During Chemotherapeutic Oxaliplatin

Oxaliplatin (OXL) is a third-generation chemotherapeutic agent commonly used to treat metastatic digestive tumors, but one of the main limiting complications of OXL is painful peripheral neuropathy. The present study was to examine the inhibitory effects of blocking microRNA-155 (miR-155) in the dorsal horn of the spinal cord on neuropathic pain induced by OXL in rats and the underlying mechanisms. Behavioral test was performed to examine mechanical pain and cold sensitivity in rats. Real-time RT-PCR and ELISA were employed to determine miR-155 and products of oxidative stress 8-isoprostaglandin F2α (8-iso PGF2α) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the dorsal horn. Western blot analysis was used to examine expression of Nrf2-antioxidant response element (Nrf2-ARE), NADPH oxidases (NOXs), and transient receptor potential ankyrin 1 (TRPA1). In results, intrathecal administration of miR-155 inhibitor attenuated mechanical allodynia and cold hyperalgesia in rats with OXL therapy and this was accompanied with restoring of impaired Nrf2-ARE in the dorsal horn. A blockade of miR-155 also attenuated expression of NOX subtype 4 (NOX4) and thereby decreased the levels of 8-iso PGF2α/8-OHdG in the dorsal horn of OXL rats. In addition, inhibiting NOX4 decreased products of oxidative stress in the dorsal horn and attenuated upregulation of TRPA1 induced by OXL. In conclusion, data show the critical role of miR-155 in regulating OXL-induced neuropathic pain likely via oxidative stress-TRPA1 signal pathway, indicating that inhibition of miR-155 has potential benefits in preventing neuropathic pain development during intervention of OXL.

Effects of Red Ginseng on Neural Injuries with Reference to the Molecular Mechanisms

Red ginseng, as an effective herbal medicine, has been traditionally and empirically used for the treatment of neuronal diseases. Many studies suggest that red ginseng and its ingredients protect the brain and spinal cord from neural injuries such as ischemia, trauma, and neurodegeneration. This review focuses on the molecular mechanisms underlying the neuroprotective effects of red ginseng and its ingredients. Ginsenoside Rb1 and other ginsenosides are regarded as the active ingredients of red ginseng; the anti-apoptotic, anti-inflammatory, and anti-oxidative actions of ginsenosides, together with a series of bioactive molecules relevant to the above actions, appear to account for the neuroprotective effects in vivo and/or in vitro. Moreover, in this review, the possibility is raised that more effective or stable neuroprotective derivatives based on the chemical structures of ginsenosides could be developed. Although further studies, including clinical trials, are necessary to confirm the pharmacological properties of red ginseng and its ingredients, red ginseng and its ingredients could be promising candidate drugs for the treatment of neural injuries.

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).