Palbinone from Paeonia suffruticosa Protects Hepatic Cells via Up‐regulation of Heme Oxygenase‐1

Paeonia suffruticosa has been traditionally employed for vitalizing blood circulation and alleviating liver and inflammatory diseases. The pathways by which palbinone (PB) isolated from P. suffruticosa mediates heme oxygenase‐1 (HO‐1) induction were investigated using the specific inhibitors for PI3K and mitogen activated protein kinases pathways. The effect of PB‐treatment on Nrf2 translocalization and HO‐1‐antioxidant response element (ARE) regulation was examined employing Western blot and luciferase assays. PB induced HO‐1 expression via the activation of Nrf2 in the hepatic cells, and ARE‐dependent genes were stimulated via the PB‐mediated Nrf2 activation. PB‐mediated HO‐1 expression could be involved with PI3K/Akt and ERK1/2 pathways. Our study suggests the mechanism by which PB induces HO‐1 expression in the hepatic cells. This might substantiate the traditional applications of P. suffruticosa for the treatment of oxidative stress‐related diseases including oxidant and inflammatory‐mediated vascular and liver diseases. Copyright © 2013 John Wiley & Sons, Ltd.     

葛根素对6-羟多巴胺所致帕金森病大鼠黑质组织Nrf2/ARE通路的影响

目的:研究葛根素对6-羟多巴胺(6-OHDA)致帕金森病(PD)大鼠黑质组织核转录因子(Nrf2)/抗氧化反应元件(ARE)通路的影响。方法:建立帕金森SD大鼠模型,随机分成5组:模型组、美多巴阳性组(40 mg.kg-1)及葛根素低、中、高剂量组(20,40,80 mg.kg-1)。持续灌胃给药30 d。Elisa法检测黑质组织中γ-谷氨酰半胱氨酸合成酶(γ-GCS)、谷胱甘肽(GSH)、过氧化氢酶(CAT)活性。RT-PCR法检测黑质组织细胞色素c氧化酶(COX)mRNA表达。Western blot法检测转录因子NF-E2相关因子2(Nrf2)、Kelch样环氧氯丙烷相关蛋白-1(Keapl)蛋白表达。结果:与正常组比较,模型组黑质中r-GCS,GSH,CAT活性显著降低,COX mRNA Nrf2,Keapl蛋白表达显著降低(P<0.01);与模型组比较,葛根素有效地增加帕金森病大鼠黑质γ-GCS,GSH,CAT活性(P<0.01)。葛根素低,中,高剂量组能明显上调黑质COX mRNA水平(38.5±4.3)%,(43.2±5.1)%,(57.4±6.2)%(P<0.01),显著增加Nrf2,Keapl蛋白表达(38.5±3.6)%,(52.4±4.8)%,(78.5±7.3)%;(31.7±2.3)%,(40.8±3.5)%,(65.9±6.1)%(P<0.01)。结论:葛根素有效地对抗6-OHDA诱导PD大鼠黑质神经细胞氧化应激性损伤,其机制可能与其调节Nrf2/ARE通路有关。     

中药基于Nrf2/ARE通路改善糖尿病心肌病的研究进展

糖尿病心肌病(diabetic cardiomyopathy,DCM)是糖尿病心血管并发症之一,约30％糖尿病患者会出现心功能障碍,并逐渐发展为DCM,最终导致心力衰竭而死亡.核因子E2相关因子2(nuclear factor NF-E2-related factor 2,Nrf2)是治疗DCM的作用靶点之一,在增强心...     

清脂化瘀颗粒调控Keap-1/Nrf2/ARE介导的氧化损伤抗动脉粥样硬化的作用及机制研究

目的:基于对动脉粥样硬化(AS)防治,观察清脂化瘀颗粒对动脉粥样硬化的防治作用及机制.方法:将30只载脂蛋白E基因敲除(ApoE-/-)小鼠随机分为模型组、阿托伐他汀组、清脂化瘀颗粒组.10只C57BL/6J雄性小鼠作为对照组.除对照组外,各组给予高脂饲料喂养8周复制AS模型,后各组小鼠分别给予对应药物干预4周.分离各...     

熊胆粉通过调节Keap1/Nrf2/ARE信号通路产生对急性酒精性肝损伤小鼠的肝保护作用＊

目的 观察研究熊胆粉（Pulvis Fellis Ursi， PFU）对急性酒精性肝损伤小鼠的肝保护作用及其可能的机理。方法 取昆明种小鼠50只，随机分为正常组、模型组、PFU低、中、高剂量组（剂量分别为150、300、600 mg·kg^-1，溶于生理盐水），每组10只。正常组和模型组小鼠每天灌胃生理盐水（10 mL·kg^-1），PFU组每天灌胃相应剂量溶液，连续8天。末次给药结束后，模型组以灌胃的方法给予50%乙醇溶液（10 mL·kg^-1），每12 h一次，共6次，末次给予50%乙醇溶液4 h后，处死小鼠并收集血清及肝脏组织。分别用生化试剂盒检测血清中ALT、AST、TG、TC和肝脏组织中GSH、T-SOD和MDA水平；用酶联免疫法检测肝脏组织TNF-α、IL-1β和IL-6水平；用HE染色法观察肝脏组织显微结构变化情况；用免疫印迹法检测肝组织总Keap1的表达和肝组织核内Nrf2的表达，用免疫印迹和免疫组化法分别检测肝组织总HO-1和GCLC蛋白的表达。结果 PFU能显著下调乙醇所致肝损伤小鼠血清中ALT、AST、TG和TC的异常升高，并改善乙醇诱导的肝脏显微结构变化。与肝损伤模型组比较，PFU组小鼠肝组织内MDA水平明显降低，GSH和T-SOD水平则明显增加。进一步研究表明，乙醇能诱导小鼠肝脏内炎症因子TNF-α、IL-1β和IL-6的上调，PFU可以剂量依赖性地缓解了上述病变。并且PFU预处理组下调了Nrf2的抑制因子Keap1的表达，从而促进了Nrf2蛋白的入核并上调了乙醇抑制的下游蛋白HO-1和GCLC的表达，从而发挥肝保护的作用。结论 熊胆粉对小鼠急性酒精性肝损伤有一定的预保护作用，其机制可能与调控肝脏内Keap1/Nrf2/ARE信号通路，恢复并上调由乙醇所破坏的肝脏氧化平衡有关。     

Paeoniflorin ameliorates ANIT‐induced cholestasis by activating Nrf2 through an PI3K/Akt‐dependent pathway in rats

Cholestasis causes hepatic accumulation of bile acids leading to liver injury, fibrosis and liver failure. Paeoniflorin, the major active compound isolated from the roots of Paeonia lactiflora pall and Paeonia veitchii Lynch, is extensively used for liver diseases treatment in China. However, the mechanism of paeoniflorin's hepatoprotective effect on cholestasis has not been investigated yet. In this study, we administered paeoniflorin to rats for 3 days prior to alpha‐naphthylisothiocyanate (ANIT) administration for once, then went on administering paeoniflorin to rats for 3 days. The data demonstrated that paeoniflorin significantly prevented ANIT‐induced change in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphates (ALP), serum total bilirubin (TBIL), direct bilirubin (DBIL), total bile acid (TBA) and gamma‐glutamyl transpeptidase (γ‐GT). Histology examination revealed that paeoniflorin treatment rats relieved more liver injury and bile duct proliferation than ANIT‐administered rats. Moreover, our data indicated that paeoniflorin could restore glutathione (GSH) and its related synthase glutamate‐cysteine ligase catalytic subunit (GCLc) and glutamate‐cysteine ligase modifier subunit (GCLm) in ANIT‐treated group. In addition, the RNA and protein expression of Akt and nuclear factor‐E2‐related factor‐2 (Nrf2) were also activated by paeoniflorin in ANIT‐induced rats. These findings indicated that paeoniflorin protected ANIT‐induced cholestasis and increased GSH synthesis by activating Nrf2 through PI3K/Akt‐dependent pathway. Therefore, paeoniflorin might be a potential therapeutic agent for cholestasis. Copyright © 2015 John Wiley & Sons, Ltd.     

Berberine ameliorates lipopolysaccharide‐induced acute lung injury via the PERK‐mediated Nrf2/HO‐1 signaling axis

A fundamental element of acute lung injury (ALI) is the inflammatory response, which can affect the entire respiratory system, including the respiratory tract and alveoli. Berberine has gained attention because of its anti‐inflammatory effects. Nuclear factor‐erythroid 2‐related factor 2 (Nrf2) and endoplasmic reticulum (ER) stress are involved in lung injury. Nrf2 also acts as a protein kinase‐like ER kinase (PERK) substrate in heart disease. Therefore, this study investigated the effect of berberine against lipopolysaccharide (LPS)‐induced ALI and the role of the PERK‐mediated Nrf2/HO‐1 signaling axis. Berberine promoted Nrf2 nuclear translocation and phosphorylation in vitro. After LPS stimulation, this effect was further enhanced, whereas inflammatory factor (IL‐6 and IL‐8) release and reactive oxygen species generation were significantly decreased. Berberine effectively alleviated lung injury by reducing lung edema and neutrophil infiltration. Berberine also significantly reduced histopathological inflammatory changes via inhibition of ER stress and activation of Nrf2 signaling. Thapsigargin‐induced ER stress and small interference RNA (siRNA)‐mediated Nrf2 inhibition abrogated the protective effects of berberine in vitro, whereas siRNA‐mediated suppression of ER stress and sulforaphane‐induced Nrf2 activation further improved those effects. Importantly, ER stress induction led to Nrf2 activation, whereas PERK depletion partly reduced the level of Nrf2 phosphorylation and translocation in LPS‐induced cells. Therefore, berberine inhibits LPS‐induced ALI through the PERK‐mediated Nrf2/HO‐1 signaling axis.     

Xanthotoxin and umbelliferone attenuate cognitive dysfunction in a streptozotocin‐induced rat model of sporadic Alzheimer's disease: The role of JAK2/STAT3 and Nrf2/HO‐1 signalling pathway modulation

The aim of the present study was to assess the neuroprotective effects of xanthotoxin and umbelliferone in streptozotocin (STZ)‐induced cognitive dysfunction in rats. Animals were injected intracerebroventricularly (ICV) with STZ (3 mg/kg) once to induce a sporadic Alzheimer's disease (SAD)‐like condition. Xanthotoxin or umbelliferone (15 mg/kg, i.p.) were administered 5 hr after ICV‐STZ and daily for 20 consecutive days. Xanthotoxin or umbelliferone prevented cognitive deficits in the Morris water maze and object recognition tests. In parallel, xanthotoxin or umbelliferone reduced hippocampal acetylcholinestrase activity and malondialdehyde level. Moreover, xanthotoxin or umbelliferone increased glutathione content. These coumarins also modulated neuronal cell death by reducing the level of proinflammatory cytokines (tumour necrosis factor‐alpha and interleukin‐6), inhibiting the overexpression of inflammatory markers (nuclear factor κB [NF‐κB] and cyclooxygenase II), and upregulating the expression of NF‐κB inhibitor (IκB‐α). Interestingly, xanthotoxin diminished phosphorylated JAK2 and phosphorylated STAT3 protein expression, while umbelliferone markedly replenished nuclear factor erythroid‐derived 2‐like 2 (Nrf2) and haem oxygenase‐1 (HO‐1) levels. The current study provides evidence for the protective effect of xanthotoxin and umbelliferone in STZ‐induced cognitive dysfunction in rats. This effect may be attributed, at least in part, to inhibiting acetylcholinestrase and attenuating oxidative stress, neuroinflammation and neuronal loss.     

Ampelopsin inhibits high glucose‐induced extracellular matrix accumulation and oxidative stress in mesangial cells through activating the Nrf2/HO‐1 pathway

Oxidative stress plays an important role in diabetic nephropathy (DN), which is a diabetic complication. Ampelopsin (AMP) is a natural flavonoid that has been found to possess antidiabetic and antioxidative activities. However, the effect of AMP on DN remains unclear. In this study, we aimed to evaluate the protective effect of AMP on glomerular mesangial cells (MCs) exposed to high glucose (HG). We found that AMP improved HG‐caused cell viability reduction in MCs. AMP significantly suppressed the intracellular ROS production and expression levels of ROS producing enzymes NADPH oxidase 2 (NOX2) and NOX4. Increased of NOX activity in HG‐stimulated MCs was suppressed by AMP. Pretreatment with AMP inhibited extracellular matrix (ECM) accumulation in HG‐stimulated MCs with decreased expression levels of fibronectin (FN) and collagen type IV (Col IV). Furthermore, AMP elevated the expression levels of nuclear Nrf2 and heme oxygenase‐1 (HO‐1), as well as increased the mRNA levels of Nrf2‐driven genes NAD(P)H dehydrogenase quinone‐1 (NQO‐1) and HO‐1 in HG‐treated MCs. Knockdown of Nrf2 reversed the protective effects of AMP against HG‐induced oxidative stress and EMC accumulation in MCs. In conclusion, these findings indicated that AMP protected MCs from HG‐induced oxidative damage and ECM accumulation, which might be mediated by Nrf2/HO‐1 pathway.     

鹅不食草介导Nrf2/HO-1信号通路在脑缺血再灌注中抗氧化抗炎作用机制研究

目的:探讨鹅不食草对脑缺血再灌注大鼠Nrf2/HO-1信号通路介导的氧化应激反应和神经炎症影响。方法:SD大鼠分为假手术组、脑缺血组、依达拉奉组、鹅不食草100 mg/kg剂量组、鹅不食草200 mg/kg剂量组、鹅不食草400 mg/kg剂量组。采用中动脉栓塞介导大鼠缺血损伤,连续给药后评价大鼠神经功能,脑组织脑梗死面积、氧化因子、炎症因子含量,Nrf2、HO-1 mRNA与蛋白含量。结果:与假手术组相比,脑缺血组大鼠神经功能显著损伤(P<0.05),脑梗死体积增加(P<0.05),氧化因子、炎症因子含量增加(P<0.05)。与脑缺血组相比,鹅不食草组与依达拉奉组改善了大鼠神经功能(P<0.05),减少脑梗死面积(P<0.05),抑制氧化应激与炎症反应(P<0.05),而Nrf2、HO-1 mRNA与蛋白表达增加(P<0.05)。结论:鹅不食草可以介导Nrf2/HO-1信号通路减少大鼠脑中氧化应激反应与炎症因子含量,改善大鼠神经功能。     

苦参素对2型糖尿病雄性大鼠生殖损伤及Nrf2/HO-1信号通路的影响

[目的]探讨苦参素（OMT）对2型糖尿病（T2DM）雄性大鼠生殖损伤及E2相关因子2(Nrf2)/血红素加氧酶1(HO-1)信号通路的影响。[方法]采用高脂饮食结合腹腔注射链脲佐菌素的方法制备T2DM雄性大鼠模型,设正常（Normal）组、模型（Model）组、二甲双胍（Met）组和OMT低、中、高剂量组,每组8只。Met组每日1次灌胃给药200 mg/kg,OMT低、中、高剂量组分别每日1次灌胃给药25、50、100 mg/kg,Normal组和Model组每日1次灌胃给予生理盐水,疗程4周。检测空腹血糖（FBG）和血清睾酮（T）、促性腺激素释放激素（GnRH）、促黄体激素（LH）、卵泡刺激素（FSH）水平,测量睾丸质量和睾丸体积,苏木精-伊红（HE）染色法观察睾丸组织病理学改变,测量输精管直径（STD）和输精管上皮厚度（TSE）,精液分析仪检测精子数量、精子存活率和精子活力,比色法检测睾丸组织抗氧化酶（SOD、GSH-Px）活性和丙二醇（MDA）含量,实时荧光定量聚合酶链式反应（RT-PCR）法检测E2相关因子2(Nrf2)、血红素加氧酶-1(HO-1)mRNA表达,蛋白免疫印迹法...     

Caffeoylserotonin Protects Human Keratinocyte HaCaT Cells against H2O2‐Induced Oxidative Stress and Apoptosis through Upregulation of HO‐1 Expression via Activation of the PI3K/Akt/Nrf2 Pathway

Caffeoylserotonin (CaS) has strong radical scavenging activity as well as antioxidant activities, protecting cells from lipid peroxidation, intracellular reactive oxygen species generation, DNA damage, and cell death. The molecular mechanism by which CaS protects against oxidative stress is not well understood. Here, we analyzed the cytoprotective activity of CaS in hydrogen peroxide (H₂O₂)‐treated keratinocyte HaCaT cells. H₂O₂ induced apoptosis in the cells through activation of pro‐apoptotic p21, Bax, and caspase‐3. Pretreatment with CaS inhibited apoptotic gene expression and activated the anti‐apoptotic gene, Bcl‐xL. Although CaS did not directly affect heme oxygenase‐1 (HO‐1) expression, pretreatment with CaS augmented HO‐1 expression through an increase in NF‐E2‐related factor (Nrf2) stability and stimulation of Nrf2 translocation to the nucleus upon H₂O₂ exposure. H₂O₂ also induced the phosphorylation and subsequent activation of ERK, p38 MAPK, and Akt. Analysis using specific inhibitors of p38 MAPK and Akt demonstrated that only Akt activation was involved in HO‐1 and Nrf2 expressions. In addition, PI3K and PKC inhibitors suppressed HO‐1/Nrf2 expression and Akt phosphorylation. These results demonstrate that CaS protects against oxidative stress‐induced keratinocyte cell death in part through the activation of Nrf2‐mediated HO‐1 induction via the PI3K/Akt and/or PKC pathways, but not MAPK signaling. Copyright © 2013 John Wiley & Sons, Ltd.     

Brassinin,a phytoalexin in cruciferous vegetables,suppresses obesity‐induced inflammatory responses through the Nrf2‐HO‐1 signaling pathway in an adipocyte‐macrophage co‐culture system

The aim of this study was to investigate the effect of brassinin (BR), a phytoalexin found in plants belonging to the Brassicaceae family, on the obesity‐induced inflammatory response and its molecular mechanism in co‐culture of 3T3‐L1 adipocytes and RAW264.7 macrophages. BR effectively suppressed lipid accumulation by down‐regulating the expression of adipogenic factors, which in turn, were regulated by early adipogenic factors such as CCAAT‐enhancer‐binding protein‐β and Kruppel‐like factor 2. Production of inflammatory cytokines and reactive oxygen species, induced by adipocyte‐conditioned medium, was significantly decreased in BR‐treated cells. This effect of BR was more prominent in contact co‐culture of adipocytes and macrophages with a 90% and 34% reduction in IL‐6 and MCP‐1 levels, respectively. BR also restored adiponectin expression, which was significantly reduced by culturing adipocytes in macrophage‐conditioned medium. In the transwell system, BR increased the protein levels of nuclear factor (erythroid‐derived 2)‐like 2 (Nrf2) and its target molecule, hemoxygenase‐1 (HO‐1), by 55%–93% and 45%–48%, respectively, and also increased Nrf2 translocation into the nucleus. However, knockdown of Nrf2 or HO‐1 in RAW264.7 cells restored this BR‐mediated inhibition of IL‐6 and MCP‐1 production. These results indicated that BR inhibited obesity‐induced inflammation via the Nrf2‐HO‐1 pathway.     

基于DJ-1/Nrf2/HO-1信号通路探讨北柴胡地上部分多糖组分对癫痫小鼠脑内氧化应激的影响

目的 探讨北柴胡Bupleurum chinense地上部分多糖组分（polysaccharides from aerial parts of B. chinense,ABP）对戊四唑致痫小鼠的预防作用及作用机制。方法 C57BL/6小鼠随机分为对照组、模型组、丙戊酸钠（125 mg/kg）组、癫痫宁片（1200 mg/kg）组和ABP高、低剂量（100、25 mg/kg）组,每组10只。各给药组ig相应药物,对照组和模型组ig等体积0.5%羧甲基纤维素钠溶液,1次/d,连续7 d。末次给药后60 min,除对照组外,其余各组ip戊四唑（60 mg/kg）。通过行为学评价ABP预防癫痫的作用;采用苏木素-伊红（HE）染色、免疫组化法检测海马神经元病理形态学变化;采用ELISA法测定海马组织中半胱氨酸天冬氨酸蛋白酶-3(cystein-asparate protease-3,Caspase-3)、胶质纤维酸性蛋白（glial fibrillary acidic protein,GFAP）、谷氨酸脱羧酶65(glutamic acid decarboxylase 65,GAD65)、GAD...     

藏红花素调控Nrf2/HO-1通路改善血管性认知障碍大鼠学习记忆能力实验研究

目的:探讨藏红花素对血管性认知障碍(VCI)大鼠学习记忆能力的影响及机制。方法:通过反复夹闭双侧颈总动脉建立VCI大鼠模型,假手术组暴露双侧颈总动脉但不夹闭; 将VCI模型大鼠随机分为模型组、藏红花素低剂量组(10 mg/kg)、藏红花素中剂量组(20 mg/kg)、藏红花素高剂量组(40 mg/kg)和多奈哌齐组(0.5 mg/kg)。连续给药4周后,评测大鼠学习能力和记忆能力,观察海马体CA1区病理性变化和神经元凋亡状况; 检测海马体CA1区氧化应激指标和炎症因子水平,Western blot法检测核因子E2相关因子2(Nrf2)、血红素氧合酶1(HO-1)、核因子-κB(NF-κB)蛋白表达。结果:藏红花素或多奈哌齐治疗4周可提高VCI大鼠学习能力和记忆能力,改善海马体CA1区病变和神经元凋亡状况,提高超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力,降低丙二醛(MDA)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)水平,上调Nrf2、HO-1表达,下调NF-κB表达(P<0.05)。上述指标除GSH-Px活力和MDA、IL-1β水平外,藏红花素对其他指标的作用均表现出剂量依赖性; 除GSH-Px活力、IL-1β水平外,藏红花素高剂量对其他指标的作用优于多奈哌齐(P<0.05)。结论:藏红花素可能通过激活Nrf2/HO-1通路降低海马体氧化应激损伤,对VCI大鼠学习记忆能力有改善作用。     

Carthamus red from Carthamus tinctorius L. exerts antioxidant and hepatoprotective effect against CCl4-induced liver damage in rats via the Nrf2 pathway

Ethnopharmacological relevance

Carthamus red isolated from safflower (Carthamus tinctorius L., a Chinese traditional medicine) is evaluated for antioxidant and hepatoprotective activity.

Materials and methods

Carthamus red was isolated from a Na₂CO₃ extract of safflower and its analysis was carried out by HPLC/MS. Acute toxicity study was determined and the antioxidant activity was investigated using various established in vitro systems. An in vivo study against CCl₄-induced liver injury was also conducted and compared with that of silymarin, a known hepatoprotective drug.

Results

Carthamus red did not show any toxicity and mortality up to 2000 mg/kg dose, and it showed strong antioxidant ability in vitro. In the in vivo study, carthamus red treatment lowered the serum levels of ALT, AST, ALP and total protein in liver damage rat models. Meanwhile, Nrf2, GSTα and NQO1 expressions were up-regulated at the protein level by carthamus red intervention. Additionally, the activities of antioxidant enzymes and level of GSH were elevated by carthamus red intervention, while the content of TBARS, which is an oxidative stress marker, was lessened. HE stain analysis showed that the condition of liver damage was mitigated.

Conclusion

This study demonstrates that carthamus red may serve as a candidate with strong a hepatoprotective effect and antioxidant activity in liver damage.     

穿山龙水提物调控Keap1/Nrf2通路抗CCl_4诱导小鼠急性肝损伤作用研究

目的:评价穿山龙水提物(AEDN)通过对Keap1/Nrf2信号通路的调控实现对CCl_4诱导小鼠急性肝损伤的保护作用。方法:穿山龙药材经水提取浓缩蒸干即为AEDN,采用紫外可见分光光度法测定提取物中多糖含量。雄性昆明小鼠经AEDN连续灌胃给药7 d后,腹腔注射0. 35%CCl_4橄榄油溶液诱导急性肝损伤,评价AEDN对CCl_4诱导急性肝损伤氧化应激相关指标的影响,并检测AEDN对Keap1/Nrf2信号通路的调控作用。结果:AEDN的提取率为9. 64%,其中多糖含量为(53. 03±0. 70)%。在CCl_4所致小鼠急性肝损伤中,AEDN能显著降低MDA的表达水平,使小鼠肝组织中的SOD、GSH和GSH-Px含量增多。此外,AEDN可显著上调SOD1、SOD2、Nrf2、GST、NQO1和HO-1的蛋白表达,降低Keap1的表达,显著下调iNOS mRNA的表达水平。结论:穿山龙水提物可通过调控Keap1/Nrf2氧化应激信号通路实现对CCl_4诱导的小鼠急性肝损伤的保护作用。     

Panax notoginseng saponins suppress lipopolysaccharide‐induced barrier disruption and monocyte adhesion on bEnd.3 cells via the opposite modulation of Nrf2 antioxidant and NF‐κB inflammatory pathways

Dysfunction of the blood‐brain barrier (BBB) is a prerequisite for the pathogenesis of many cerebral diseases. Oxidative stress and inflammation are well‐known factors accounting for BBB injury. Panax notoginseng saponins (PNS), a clinical commonly used drug against cerebrovascular disease, possess efficient antioxidant and anti‐inflammatory activity. In the present study, the protective effects of PNS on lipopolysaccharide (LPS)‐insulted cerebral microvascular endothelial cells (bEnd.3) were assessed and the underlying mechanisms were investigated. The results showed that PNS mitigated the decrease of Trans‐Endothelial Electrical Resistance, increase of paracellular permeability, and loss of tight junction proteins in bEnd.3 BBB model. Meanwhile, PNS suppressed the THP‐1 monocytes adhesion on bEnd.3 monolayer. Moreover, PNS prevented the pro‐inflammatory cytokines secretion and reactive oxygen species generation in bEnd.3 cells stimulated with LPS. Mechanism investigations suggested that PNS promoted the Akt phosphorylation, activated Nrf2 antioxidant signaling, and inhibited the NF‐κB activation. All the effects of PNS could be abolished by PI3K inhibition at different levels. Taken together, these observations suggest that PNS may act as an extrinsic regulator that activates Nrf2 antioxidant defense system depending on PI3K/Akt and inhibits NF‐κB inflammatory signaling to attenuate LPS‐induced BBB disruption and monocytes adhesion on cerebral endothelial cells in vitro.     

苦参水提物激活Nrf2/HO-1信号通路抑制炎症和氧化应激机制研究

目的研究苦参水提物(WSF)抑制脂多糖(LPS)诱导大鼠巨噬细胞RAW264.7炎症和氧化应激的分子机制。方法采用CCK-8法检测WSF对RAW264.7细胞的最佳给药质量浓度;以LPS刺激RAW264.7细胞制备体外炎症模型,随机分为对照组、模型组、WSF组和WSF对照组,流式细胞术检测活性氧(ROS)及一氧化氮(NO)水平,通过荧光定量PCR(qRT-PCR)和Western blotting检测诱导型一氧化氮合酶(iNOS)、环氧合酶-2(COX-2)、核转录因子E2相关因子2(Nrf2)和血红素加氧酶-1(HO-1)在分子水平上的变化;最后检测细胞培养上清中细胞因子白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)和IL-10的含量。结果通过CCK-8实验确定WSF质量浓度为0.01 mg/mL对细胞无毒性。与对照组比较,LPS刺激能够显著地增加细胞中NO和ROS产生,IL-6和TNF-α水平也明显升高,iNOS和COX-2蛋白表达水平明显提高(P0.01、0.001),而Nrf2和HO-1蛋白表达水平降低(P0.05)。与模型组比较,WSF干预后细胞NO、ROS、IL-6和TNF-α水平显著降低,iNOS和COX-2蛋白表达水平显著降低(P0.05、0.01、0.001),Nrf2和HO-1蛋白表达水平和IL-10水平显著升高(P0.05、0.01、0.001)。结论 WSF可通过激活Nrf2/HO-1通路在LPS诱导的RAW264.7细胞炎症和氧化应激反应中发挥保护效应。