The nuclear factor E2-related factor 2 and age-related macular degeneration / O fator 2 relacionado a NF-E2 e a degeneração macular relacionada à idade

ABSTRACT After the discovery of anti-vascular endothelial growth factor agents as treatment of wet age-related macular degeneration, the number of studies with the objective to understand the molecular mechanisms involved in the age-re lated macular degeneration genesis has increased. The importance of the nuclear factor e2-related factor 2 lies in its activation-derived proteins being involved in the maintenance of the redox balance and consequent prevention of degenerative macular disease. This article aims to present the characteristics of nuclear factor e2-related factor 2 and describe the main nuclear factor e2-related factor 2-activated antioxidant enzymes that contribute to the preservation of vision.

RESUMO Após a descoberta do anti fator de crescimento en dotelial vascular no tratamento da degeneração macular relacionada à idade úmida, muitas pesquisas têm sido realizadas com o intuito de elucidar os mecanismos moleculares envolvidos na gênese da degeneração macular relacionada à idade. O fator nuclear eritroide 2 relacionado ao fator 2 destaca-se pelo fato de diversas proteínas, oriundas de sua ativação, estarem envolvidas na manutenção do equilíbrio do estado redox e consequente prevenção da doença macular degenerativa. Este artigo mostra as características do fator nuclear eritroide 2 relacionado ao fator 2 e descreve as principais enzimas antioxidantes originadas da ativação que contribuem para a preservação da visão.

Protective Effect of Alcohol Extract of Phyllanthi Fructus on Silicosis Mice and Its Correlation with Nrf2/ARE Signaling Pathway / 中国实验方剂学杂志

ObjectiveTo explore the effect and underlying mechanism of alcohol extract of Phyllanthi Fructus on silicosis mice induced by silicon dioxide （SiO2）. MethodThirty-six male Kunming mice of SPF grade were randomly divided into a blank group，a model group，high-， medium， and low-dose Phyllanthi Fructus groups （800， 400， 200 mg·kg-1），and a tetrandrine group （0.039 mg·kg-1），with six mice in each group. The silicosis model was induced by static SiO2 exposure in mice except for those in the blank group. After 28 days of administration by gavage，the lung tissues were collected and the organ coefficient was calculated. Hematoxylin-eosin（HE）staining and Masson staining were used to detect the morphology of lung tissues. The content of hydroxyproline （HYP），superoxide dismutase （SOD），malondialdehyde （MDA）， and catalase （CAT） in serum was detected by enzyme-linked immunosorbent assay （ELISA）. Western blot and Real-time polymerase chain reaction（Real-time PCR） were used to detect the protein and mRNA expression of nuclear factor E2-related factor 2 （Nrf2），heme oxygenase-1 （HO-1），NAD（P）H：quinone oxidoreductase 1 （NQO1），and Kelch-like ECH-associated protein 1 （Keap1）， respectively. ResultCompared with the blank group，the model group showed seriously damaged morphological structure of lung tissues with inflammatory cell infiltration and fibrous tissue proliferation， reduced serum content of SOD and CAT（P<0.01），increased content of HYP and MDA（P<0.01）， down-regulated protein and mRNA expression of Nrf2，HO-1， and NQO1（P<0.01），and up-regulated protein and mRNA expression of Keap1 （P<0.05，P<0.01）. Compared with the model group，the high- and medium-dose Phyllanthi Fructus groups showed significantly restored morphological structure of lung tissues with reduced collagen deposition， increased serum content of SOD and CAT（P<0.05，P<0.01），decreased content of HYP and MDA（P<0.01）， up-regulated protein and mRNA expression of Nrf2，HO-1， and NQO1 （P<0.05，P<0.01），and down-regulated protein and mRNA expression of Keap1（P<0.05，P<0.01）. ConclusionThe alcohol extract of Phyllanthi Fructus can inhibit pulmonary fibrosis in silicosis mice，and the underlying mechanism may be related to the regulation of the Nrf2/antioxidant response element （ARE） signaling pathway.

Neuroprotection of Natural Products Based on Keap1/Nrf2/ARE Signaling Pathway： A Review / 中国实验方剂学杂志

The pathological manifestations of neurodegenerative diseases， such as Alzheimer's disease， Parkinson's disease， and multiple sclerosis， are abnormal protein aggregation and accumulation， microglia activation， and mitochondrial dysfunction， which eventually lead to the gradual loss of neuronal structure or function and deteriorate over time. These pathological processes are related to the production of reactive oxygen species （ROS）， which can cause oxidative stress and damage proteins， lipids， and DNA， leading to cell and tissue injuries. The Kelch-like ECH-associated protein 1 （Keap1）/nuclear factor E2-related factor 2 （Nrf2）/antioxidant response element （ARE） signaling pathway is the main mechanism to maintain the redox balance of the body and defend against oxidative stress injury. Nrf2 activates the expression of a series of antioxidant genes related to ARE through the dissociation of Keap1 and nuclear transfer in the cytoplasm to protect the body from oxidative damage. Therefore， the discovery and study of the Keap1/Nrf2/ARE signaling pathway activator is of great significance for the prevention and treatment of neurodegenerative diseases. Because of the remarkable biological activity and slight side effects， natural products are a treasure trove for new drug research and development. Studies have shown that a variety of natural products can activate the Keap1/Nrf2/ARE signaling pathway and play a neuroprotective role. According to the structural characteristics， natural products can be divided into flavonoids， terpenoids， volatile oils， polyphenols， and phenylpropanoids. This study summarized the underlying mechanism of the Keap1/Nrf2/ARE signaling pathway in regulating diseases and reviewed the research progress on natural products based on this signaling pathway in neuroprotection to provide references for the development of clinical drugs for the prevention and treatment of neurodegenerative diseases.

Shenling Baizhusan Improves Spermatogenesis in Hyperuricemia Oligoasthenospermia Mice by Regulating Nrf2/ARE Pathway / 中国实验方剂学杂志

ObjectiveTo investigate the effect and mechanism of Shenling Baizhusan on the treatment of oligoasthenospermia with hyperuricemia （HUA）. MethodThirty-two male Kunming （KM） mice were randomly divided into blank group （n=6）， model group （n=6）， high-dose Shenling Baizhusan group （n=7）， low-dose Shenling Baizhusan group （n=7）， and febuxostat group （n=6）. Except for the blank group， all other groups received intraperitoneal injection of potassium oxazinate suspension （600 mg·kg-1） for 7 days. After modeling， the high-dose Shenling Baizhusan group and the low-dose Shenling Baizhusan group were orally administered with 20.14 g·kg-1 and 10.07 g·kg-1 of Shenling Baizhusan， respectively. The Febuxostat group was orally administered with 0.25 g·kg-1 of Febuxostat， while the blank group and model group were orally administered with the same volume of physiological saline. Oral administration was performed once a day for 14 consecutive days， after which samples were collected. Biochemical methods were used to measure serum uric acid （UA）， superoxide dismutase （SOD） and malondialdehyde （MDA） in testicular tissue. Hematoxylin-eosin （HE） staining was used to observe the histopathological changes in testicular tissue and evaluate the spermatogenesis function. Automated sperm analyzer was used to measure sperm density and motility. Single-cell gel electrophoresis （SCGE） was used to assess sperm DNA integrity. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） was used to detect testicular cell apoptosis rate. Western blot analysis was performed to measure the protein expression levels of Kelch-like ECH-associated protein 1 （Keap1）， nuclear factor E2-related factor 2 （Nrf2）， heme oxygenase-1 （HO-1）， B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， and Caspase-3 in testicular tissue. Real-time polymerase chain reaction （PCR） was conducted to evaluate the mRNA expression levels of Keap1， Nrf2， and HO-1 in testicular tissue. ResultCompared with the blank group， the model group showed elevated serum UA level （P<0.01）， decreased testicular spermatogenesis function， sperm density， and motility （P<0.01）， and increased sperm trailing rate and testicular cell apoptosis rate （P<0.01）. Compared with the model group， the high-dose Shenling Baizhusan group showed significant improvements in the above-mentioned indicators （P<0.05， P<0.01）. Additionally， the expression levels of Keap1， Bax， and Caspase-3 in testicular tissue were reduced， while the expression levels of Nrf2， HO-1， and Bcl-2 increased （P<0.05， P<0.01）. The mRNA level of Keap1 decreased （P<0.05， P<0.01）， while the mRNA levels of Nrf2 and HO-1 increased （P<0.05， P<0.01）. ConclusionShenling Baizhusan can significantly improve HUA oligoasthenospermia， and its mechanism may be related to the Nrf2/antioxidant response element （ARE） signaling pathway.

Protective Mechanism of Total Flavonoids of Lavender Against Skin Photoaging in Mice / 中国实验方剂学杂志

ObjectiveTo study the protective effect of total flavonoids of lavender on skin photoaging induced by ultraviolet B （UVB） in mice and to explore its mechanism from the perspective of nuclear factor E2-related factor 2 （Nrf2） antioxidant pathway. MethodEighty-four female KM mice were randomly divided into seven groups， namely blank group， model group， solvent group， vitamin E （0.013 g·kg-1） group， as well as low-， middle-， and high-dose （0.25， 1.25， 2.50 g·kg-1） groups of total flavonoids of lavender. The naked skin on the back of mice was irradiated with UVB for inducing optical damage. Thirty minutes before irradiation， the skin was coated with the total flavonoids of lavender. After continuous irradiation for one week， the skin moisture and elasticity on the back of mice were evaluated， and the effects of total flavonoids of lavender on histopathological changes in mouse skin were investigated by hematoxylin-eosin （HE） and Van Gieson （VG） staining. The levels of malondialdehyde （MDA）， superoxide dismutase （SOD）， total antioxidant capacity （T-AOC）， nitric oxide synthase （NOS）， and glutathione peroxidase （GSH-Px） after skin homogenization were detected by colorimetry， the inflammatory factors interleukin-1 （IL-1）， interleukin-6 （IL-6） and tumor necrosis factor-α （TNF-α） in skin tissue by enzyme-linked immunosorbent assay （ELISA）， and the mRNA expression levels of Nrf2， Kelch-like epichlorohydrin-associated protein 1 （Keap1）， BTB-CNC homology 1 （Bach1）， heme oxygenase-1 （HO-1）， quinone oxidoreductase 1 （NQO1）， and glutamate-cysteine ligase catalytic subunit （GCLC） by real-time polymerase chain reaction （Real-time PCR）. ResultCompared with the blank group， the model group exhibited significantly increased appearance score （P<0.01）， reduced skin moisture and elasticity （P<0.01）， pronounced pathological changes in the skin tissue like epidermal thickening， scabbing， small abscess， and severe injury， elevated MDA， NOS， IL-1， IL-6 and TNF-α （P<0.05， P<0.01）， lowered SOD， T-AOC， Nrf2， Keap1， NQO1 and GCLC mRNA expression （P<0.05，P<0.01）， and up-regulated Bach1 mRNA expression （P<0.01）. Compared with the model group， the total flavonoids of lavender at the low， middle， and high doses all remarkably reduced the appearance score （P<0.01）， enhanced the skin moisture and elasticity （P<0.01）， diminished the MDA， NOS， IL-1， IL-6， and TNF-α （P<0.05， P<0.01）， increased SOD， T-AOC， Nrf2， Keap1， NQO1， HO-1 and GCLC mRNA expression （P<0.05， P<0.01）， and down-regulated the expression of Bach1 mRNA （P<0.01）. ConclusionThe protective effect of the total flavonoids of lavender against skin photoaging in mice is significant， which may be related to its activation of Keap1/Nrf2/ARE signaling pathway， regulation of oxidative stress， and improvement of inflammatory response.

Recommendations for the use of the acetaminophen hepatotoxicity model for mechanistic studies and how to avoid common pitfalls

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug, which is safe at therapeutic doses but can cause severe liver injury and even liver failure after overdoses. The mouse model of APAP hepatotoxicity recapitulates closely the human pathophysiology. As a result, this clinically relevant model is frequently used to study mechanisms of drug-induced liver injury and even more so to test potential therapeutic interventions. However, the complexity of the model requires a thorough understanding of the pathophysiology to obtain valid results and mechanistic information that is translatable to the clinic. However, many studies using this model are flawed, which jeopardizes the scientific and clinical relevance. The purpose of this review is to provide a framework of the model where mechanistically sound and clinically relevant data can be obtained. The discussion provides insight into the injury mechanisms and how to study it including the critical roles of drug metabolism, mitochondrial dysfunction, necrotic cell death, autophagy and the sterile inflammatory response. In addition, the most frequently made mistakes when using this model are discussed. Thus, considering these recommendations when studying APAP hepatotoxicity will facilitate the discovery of more clinically relevant interventions.

Protective Effect of Angelicae Sinensis Radix-Chuanxiong Rhizoma Medicated Serum Against H2O2-induced Oxidative Damage of PC12 Cells Based on Nrf2/ARE Signaling Pathway / 中国实验方剂学杂志

Objective:To investigate the protective effect and molecular mechanism of Angelicae Sinensis Radix-Chuanxiong Rhizoma medicated serum （ASRCRS） against oxidative damage of PC12 cells induced by H₂O₂. Method:Oxidative damage of PC12 cells was induced by H₂O₂<italic> in vitro</italic>， and intervention was performed in the low-， medium-， and high-dose ASRCRS groups with a final volume fraction of 15%. The cell viability was determined by methyl thiazolyl tetrazolium （MTT） assay. Cell morphology was observed by an inverted fluorescence microscope. The content of lactate dehydrogenase （LDH） and malondialdehyde （MDA）， the activity of superoxide dismutase （SOD）， and the distribution of reactive oxygen species （ROS） in the cell supernatant were detected by the kits. Cell apoptosis was detected by Annexin V-FITC/PI double staining. The protein expression levels of nuclear factor E₂-related factor 2 （Nrf2）， Kelch-like epichlorohydrin associated protein-1 （Keap1）， heme oxygenase-1 （HO-1）， and SOD1 were detected by Western blot. Result:Oxidative damage was induced by 300 μmol·L^-1 H₂O₂ for 24 hours. Compared with the normal group， the model group showed abnormal cell morphology， reduced cell viability （<italic>P</italic><0.01）， increased LDH and MDA （<italic>P</italic><0.01）， blunted SOD activity， elevated intracellular distribution of ROS， down-regulated protein expression of Nrf2， HO-1， and SOD1 （<italic>P</italic><0.05， <italic>P</italic><0.05）， and up-regulated protein expression of Keap1 （<italic>P</italic><0.01）. Compared with the model group， ASRCRS groups displayed improved cell morphology， increased cell viability， inhibited cell apoptosis， potentiated SOD activity （<italic>P</italic><0.01）， suppressed release of LDH （<italic>P</italic><0.01） and generation of ROS， decreased content of MDA （<italic>P</italic><0.01）， up-regulated protein expression of Nrf2， HO-1 and SOD1 （<italic>P</italic><0.05， <italic>P</italic><0.01）， and down-regulated protein expression of Keap1 （<italic>P</italic><0.01）. Conclusion:ASRCRS could protect PC12 cells from oxidative damage induced by H₂O₂ by up-regulating the expression of Nrf2 to activate the Nrf2/antioxidant response element （ARE） signaling pathway， enhancing the ability to resist oxidative damage， and inhibiting cell apoptosis.

Effect and Mechanism of Banxia Xiexintang on Rats with Chronic Atrophic Gastritis Based on Keap1/Nrf2/ARE Signaling Pathway / 中国实验方剂学杂志

Objective:To explore the mechanism of Banxia Xiexintang （BXXX） in preventing and treating chronic atrophic gastritis （CAG） through Kelch-like ECH-associated protein 1 （Keap1）/nuclear factor erythroid 2-related factor 2 （Nrf2）/antioxidant response element （ARE） signaling pathway. Method:SD rats were divided into a normal group （<italic>n</italic>=12） and an experimental group for CAG model induction. The model rats were then randomly divided into a model group， a vatacoenayme （VG） group （60 mg·kg^-1）， and high- （280 mg·kg^-1）， medium- （140 mg·kg^-1）， and low-dose （70 mg·kg^-1） BXXX groups. The doses in the BXXX groups were equivalent to 28， 14， and 7 g·kg^-1 crude drugs. The rats in the normal group and the model group received distilled water at an equal volume， and those in the VG group and the BXXX groups were treated correspondingly by gavage. After 12 weeks of treatment， hematoxylin-eosin （HE） staining was carried out to observe pathological changes in the gastric mucosa of CAG rats. Western blot and real-time fluorescence-based quantitative PCR was used to detect the protein and mRNA expression levels of Nrf2， glutathione S-transferase （GST）， and NAD （P）H：quinone oxidoreductase 1 （NQO1） in the gastric mucosa of CAG rats. Result:Compared with the normal group， the model group showed increased protein and mRNA expression levels of Nrf2， NQO1， and GST in the gastric mucosa of the rats （<italic>P</italic><0.05）， atrophic gastric mucosa， and even intestinal metaplasia. The protein and mRNA expression levels of Nrf2， NQO1， and GST in the VG group and the high- and medium-dose BXXX groups were lower than those in the model group （<italic>P</italic><0.05）， and gastric mucosa atrophy and intestinal metaplasia were significantly improved， especially in the high-dose BXXX group. However， the effect in the low-dose BXXX group was not significant. Conclusion:BXXX can blunt the transcriptional activity of Nrf2， shut down Nrf2 signaling pathway， and reduce the expression levels of NQO1 and GST to achieve normal oxidation-anti-oxidation balance， which may be one of its action mechanisms in the treatment of CAG.

Effect and Mechanism of Shaofu Zhuyutang on Endothelial Injury of Rats with Cold Coagulation and Blood Stasis Syndrome Based on Nrf2/ARE Signaling Pathway / 中国实验方剂学杂志

Objective:To observe the effect of Shaofu Zhuyutang on nuclear factor erythroid-2-related factor 2 （Nrf2） /antioxidant response element （ARE） signaling pathway in blood vessels by establishing the model of rats with cold coagulation and blood stasis syndrome， and to explore the protective effect and mechanism of Shaofu Zhuyutang on vascular endothelial injury. Method:The 50 SPF rats were randomly divided into high dose group （4.8 g·kg-1）， middle dose group （2.4 g·kg-1）， low dose group （1.2 g·kg-1）， model group and normal group （ten of each group）. The rat model of cold coagulation and blood stasis syndrome was established by subcutaneous injection of epinephrine hydrochloride combined with ice bath. At the same time of modeling， the drug was administered by gavage. After 28 days of continuous administration， the hemorheology indexes were detected by automatic hemorheology instrument. Levels of nitric oxide （NO）， endothelin （ET）-1， superoxide dismutase （SOD）， glutathione （GSH-Px）， intercellular adhesion molecule-1（ICAM-1）， vascular cell adhesion molecule-1（VCAM-1）， von Willebrand factor （vWF） in serum were determined by ELISA. Hematoxylin and eosin （HE） staining was used to observe the endothelial injury of vascular tissue of thoracic aorta. The protein expression of Nrf2 and HO-1 in vascular tissue of thoracic aorta was detected by Western blot. Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR）was used to observe the expression of Nrf2 and heme oxygenase-1 （HO-1） mRNA in vascular tissue of thoracic aorta. Result:Compared with the blank group， model group rats whole blood viscosity and plasma viscosity were significantly increased （P<0.05，P<0.01）， vWF， ICAM 1， VCAM 1 content increased significantly （P<0.01）， NO， SOD， gsh-px levels decreased significantly （P<0.01）， significantly increased the content of ET-1（P<0.01）， thoracic aorta vascular tissue Nrf2， HO-1 mRNA expression was significantly increased （P<0.01）， Nrf2 protein expression in the cell nucleus increased significantly （P<0.05）， The protein expression level of Nrf2 in cytoplasm was significantly decreased （P<0.05）， while the protein expression level of HO-1 was significantly increased （P<0.01）. Compared with model group， the whole blood viscosity （high and middle cut）， plasma viscosity， were significantly reduced in high and meduim-dose Shaofu Zhuyutang groups（P<0.05，P<0.01）. The levels of vWF， ICAM-1， VCAM-1 and ET-1 in serum were significantly reduced （P<0.05，P<0.01）， NO， SOD and GSH-Px increased significantly （P<0.05，P<0.01）. The pathological changes such as hyperplasia， swelling and shedding of endothelial cells of thoracic aorta， rupture of internal elastic membrane and disorder of smooth muscle arrangement were improved. The expression levels of Nrf2， HO-1 protein and gene were significantly increased in vascular tissue of thoracic aorta （P<0.01）. Conclusion:Shaofu Zhuyutang has a protective effect on vascular endothelial injury in rats with cold coagulation and blood stasis syndrome. The mechanism of action is related to the activation of Nrf2/ARE signaling pathway， which leading to the increased expression of antioxidant enzymes and decreased the expression of adhesion factors.

SIRT6 as a key event linking P53 and NRF2 counteracts APAP-induced hepatotoxicity through inhibiting oxidative stress and promoting hepatocyte proliferation

Acetaminophen (APAP) overdose is the leading cause of drug-induced liver injury, and its prognosis depends on the balance between hepatocyte death and regeneration. Sirtuin 6 (SIRT6) has been reported to protect against oxidative stress-associated DNA damage. But whether SIRT6 regulates APAP-induced hepatotoxicity remains unclear. In this study, the protein expression of nuclear and total SIRT6 was up-regulated in mice liver at 6 and 48 h following APAP treatment, respectively.

4′-O-β-D-Glucosyl-5-O-Methylvisamminol Attenuates Pro-Inflammatory Responses and Protects against Oxidative Damages

We attempted to examine anti-inflammatory and anti-oxidant effects of 4′-O-β-D-glucosyl-5-O-methylvisamminol (GOMV), the first epigenetic inhibitor of histone phosphorylation at Ser10. While GOMV did not affect the viability of murine macrophage RAW 264.7 cells, it significantly suppressed lipopolysaccharide (LPS)-induced generation of prostaglandin E₂ (PGE₂) and nitric oxide (NO) through transcriptional inhibition of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). GOMV also scavenged free radicals in vitro, increased NF-E2-related factor 2 (NRF2), and activated antioxidant response element (ARE), thereby resulting in the induction of phase II cytoprotective enzymes in human keratinocyte HaCaT cells. Finally, GOMV significantly protected HaCaT cells against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced oxidative intracellular damages. Together, our results illustrate that GOMV possesses anti-inflammatory and anti-oxidant activity.

Effect of Trillin on Oxidative Stress and Nuclear Factor E2-related Factor 2/Antioxidant Response Element Pathway in Rats after Spinal Cord Injury / 中国康复理论与实践

Objective:To explore the effect of trillin on oxidative stress response and nuclear factor E2-related factor 2/antioxidant response element (Nrf2/ARE) pathway in rats after spinal cord injury (SCI). Methods:A total of 108 male Sprague-Dawley rats were randomly divided into sham group (n = 36), model group (n = 36) and trillin group (n = 36), each group was divided into one day, three days and seven days subgroups, with twelve rats in each subgroup. The SCI model was established by modified Allen's heavy strike method in the model group and the trillin group, but no obvious injury in the sham group. The trillin group was given trillin 200 mg/kg every day, and the same amount of normal saline was given in the sham group and model group, twice a day. BBB score was performed one day, three days and seven days after modeling. Morphological changes were tested by Nissl's staining, and the changes of malonaldehyde (MDA) content and superoxide dismutase (SOD) activity were detected by ELISA seven days after modeling. The expression of Nrf2, Kelch like ECH associated protein 1 (Keap1), NAD(P)H quinone oxidoreductase (NQO1) and haemoxygenase 1 (HO-1) were detected by Western blotting one day, three days and seven days after modeling. Results:Compared with the model group, BBB scores increased (P < 0.05); the structure of spinal cord was more complete and the number of Nissl bodies increased; SOD activity increased (P < 0.05) and MDA content decreased (P < 0.05); the expression of Nrf2, Keap1, NQO1 and HO-1 increased (P < 0.05) in the trillin group. Conclusion:Trillin may play a protective role in spinal cord injury by inhibiting oxidative stress response and improving the motor function.

Effect of tea polyphenols on diabetic nephropathy mice by regulating Nrf-2/ARE signaling pathway / 国际生物医学工程杂志

Objective To investigate the effects of tea-polyphenols on diabetic nephropathy (DN) mice by regulating nuclear factor E2-related factor 2/antioxidant response element (Nrf-2/ARE) signaling pathway. Methods A total of ten male 9-week-old normal (db/m) mice were randomly and equally divided into blank control group and tea-polyphenol control group, and ten male 9-week-old homologous type 2 diabetes (db/db) mice were randomly divided into model group and tea polyphenol treatment group. The animals in the tea-polyphenol control group and the treatment group were given 50 mg/(kg·d) tea-polyphenols by oral gavage, and the animals in the blank control group and model group were given same volume of double distilled water. The administration was once a day for 8 weeks. The blood glucose and 24-hour urine protein quantization (24 h-UP) were measured and recorded at 0, 4, and 8 weeks. After 8 weeks of the treatment, the mice were sacrificed. The intraocular blood stasis samples were collected for renal function indicators (serum creatinine and urea nitrogen), and kidney tissue samples were also collected for the tests of superoxide dismutase (SOD), reactive oxygen species, and malondialdehyde. Periodic acid Schiff reaction (PAS) staining was used to observe glomerular injury and scored. Western blot was used to detect the expression of Nrf-2 and hemeoxygenase-1 (HO-1) protein. Results Compared with the blank control group, the blood glucose and 24 h-UP of the mice in the model group and the tea-polyphenol treatment group increased after 4 and 8 weeks of the treatment (all P<0.01). Compared with the blank control group, after 8 weeks of the treatment, the serum creatinine and blood urea nitrogen of the model group and the tea-polyphenol treatment group increased (all P<0.01), the content of SOD in the renal tissue decreased (all P<0.01), the content of active oxygen and malondialdehyde, the relative expression of Nrf-2 and HO-1 protein increased (all P<0.01), and the glomerular injury aggravated (all P<0.01). However, there were no significant differences in all the indexes between the tea-polyphenol control group and the blank control group (all P>0.05). Conclusions Renal tissue of DN mice will undergo significant oxidative stress injury. Tea-polyphenols may reduce the oxidative stress injury in DN mice by regulating the Nrf-2/ARE signaling pathway, and play a protective role in the kidney.

Efecto del ejercicio físico sobre marcadores de estrés oxidativo en pacientes con diabetes mellitus tipo 2 / Exercise and oxidative stress in type 2 diabetes mellitus

Sedentarism, overweight and malnutrition generate an increase in the production of reactive oxygen species leading to a state of chronic oxidative stress. In patients with type 2 diabetes mellitus, oxidative stress alters pancreatic insulin secretion and the actions of the hormone on target cells, contributing to the development of micro and macrovascular complications. During physical exertion a state of transient oxidative stress occurs. As a consequence, the organism generates multiple physiological adaptations to these repetitive stimuli. Physical exercise is beneficial for type 2 diabetes mellitus but there is a paucity of information about the effects of physical exercise on biomarkers of oxidative stress in patients with the disease. We herein try to elucidate if the effects of exercise on oxidative stress can help in the prevention and treatment of type 2 diabetes mellitus and which is the most effective modality of physical exercise to reduce oxidative stress markers.

extract (Wuzhi Tablet) protects against chronic-binge and acute alcohol-induced liver injury by regulating the NRF2-ARE pathway in mice

Alcohol abuse leads to alcoholic liver disease and no effective therapy is currently available. Wuzhi Tablet (WZ), a preparation of extract fromthat is a traditional hepato-protective herb, exerted a significant protective effect against acetaminophen-induced liver injury in our recent studies, but whether WZ can alleviate alcohol-induced toxicity remains unclear. This study aimed to investigate the contribution of WZ to alcohol-induced liver injury by using chronic-binge and acute models of alcohol feeding. The activities of ALT and AST in serum were assessed as well as the level of GSH and the activity of SOD in the liver. The expression of CYP2E1 and proteins in the NRF2-ARE signaling pathway including NRF2, GCLC, GCLM, HO-1 were measured, and the effect of WZ on NRF2 transcriptional activity was determined. We found that both models resulted in liver steatosis accompanied by increased transaminase activities, but that liver injury was significantly attenuated by WZ. WZ administration also inhibited CYP2E1 expression induced by alcohol, and elevated the level of GSH and the activity of SOD in the liver. Moreover, the NRF2-ARE signaling pathway was activated by WZ and the target genes were all upregulated. Furthermore, WZ significantly activated NRF2 transcriptional activity. Collectively, our study demonstrates that WZ protected against alcohol-induced liver injury by reducing oxidative stress and improving antioxidant defense, possibly by activating the NRF2-ARE pathway.

Investigation of Effects And Mechanisms of Nrf2-ARE Pathway on Uremic Serum-Mediated Endothelial Dysfunction in Human Aortic Endothelial Cells / 中山大学学报(医学科学版)

[Objective] To investigate the effects and mechanisms of Nrf2-ARE (nuclear factor erythroid-2 related factor-anti-oxidant response element) pathway on uremic serum-mediated endothelial dysfunction in human aortic endothelial ceils.[Methods] Human aortic endothelial cells were incubated in endothelial cell medium containing 10％ normal serum,10％ non-diabetic nuremic serum or 10％ diabetic uremic serum respectively,and 20 μmol/L tertiary butyl hydroquinone (tBHQ) were pretreated with cells to active Nrf2-ARE pathway.The cells apoptosis rate were measured by flow cytometry,and the synthesis of NO was detected by flow cytometry and immune fluorescent confocal,while the expression of P-eNOSer1177/eNOS,and quinone oxidoreductase-1 (NQO1) were measured by western blotting.The levels of malondialdehyde,superoxide dismutase,eatalase,and glutathione in these cells were also measured with kits.[Results] Aortic endothelial cells incubated with uremic serum had a higher level of apoptosis rate and MDA (P ＜ 0.05),and a lower level of NO systhesis,P-eNOSSer1177/eNOS expression,CAT,SOD,GSH (P ＜ 0.05).Pretreated with tBHQ can reduce the apoptosis rate and MDA level (P ＜ 0.05),improve the amount of NO systhesis,the expression of P-eNOSSer1177/eNOS,the levels of CAT,SOD,and GSH in these cells (P ＜ 0.05).[Conclusion] Activation of Nrf2-ARE pathway can improve endothelial dysfunction in aortic endothelial cells induced by uremic serum,and its mechanism might be related with enhancement of the antioxidant stress.

Protective Effects of Zhen-Gan Xi-Feng Decoction-containing Serum on 6-OHDA-induced Oxidative Stress in PC12 Cells through Nrf2-ARE Pathway Activation / 世界科学技术-中医药现代化

This paper was aimed to study the protective effects and related mechanisms of Zhen-Gan Xi-Feng (ZGXF) decoction containing serum on 6-OHDA-induced oxidative stress in PC12 cells.The ZGXF decoction containing rat serum with low-,medium-,and high-dose (8,16,or 32 g.kg-1) or blank serum was used to preprocess PC12 cells for 1 h,and cultured together with 100 μM 6-OHDA for 24 h.And then,cells were collected.The fluorescent probe 2',7'-dichlorofluorescin diacetate (DCFH-DA) and fluorescence microplate reader were used to detect the level of reactive oxygen species (ROS).Real-time quantitative PCR was used to analyze the mRNA expressions of nuclear factor erythroid 2-related factor 2 (Nrf2),Nfe2l2,heme oxygenase-1 (HO-1),glutamate-cysteine ligase catalytic subunit (GCLc),and GCL modulatory subunit (GCLm).The luciferase report gene system was used to detect the antioxidant response element (ARE) activation.The results showed that ZGXF decoction-containing serum inhibited the 6-OHDA-induced oxidative stress,upregulated the Nfe2l2,HO-1 and GCLc mRNA expressions in cells processed with 6-OHDA.However,it has no significant effect on GCLm mRNA expression.It was concluded that ZGXF decoction-containing serum had protective effects on 6-OHDA-induced oxidative stress in PC 12 cells.Its mechanism may be correlated with the upregulation on Nfe2l2 mRNA expression,which activated ARE and further induced its downstream gene of phase Ⅱ detoxifying enzyme,as well as the HO-1 and GCLc mRNA expressions of antioxidant enzyme gene.

Screening for the Active Ingredients of Ziziphus jujuba with Neuroprotective Effects and Their Mechanisms of Action / 中国药房

OBJECTIVE:To conduct screening for the active ingredients of Ziziphus jujuba with neuroprotective effect and to il-luminate their mechanisms of action preliminarily. METHODS:After neuron-like cells (PC12 cells) were respectively cultured in the ingredient of Z. jujuba with polysaccharide enriched(1 mg/ml),that with polysaccharide removed(1 mg/ml),7 kinds of flavo-noid ingredients of Z. jujuba(catechin,procyanidine B2,epicatechin,hyperoside,rutin,quercetin-3-β-D-glucoside and kaempfer-ol-3-O-rutinoside,represented by A,B,C,D,E,F,G,all at the concentrations of 3,13,30 μmol/L)and 2 kinds of nucleoside ingredients of Z. jujuba (cyclic adenosine monophosphate and cyclic guanosine monophosphate,both at the concentrations of 3, 13,30 μmol/L)for 24 h,tert-butyl hydroperoxide(tBHP,150 μmol/L)was used to act on PC12 cells for 3 h to induce oxidative cellular damage,and MTT assay was employed to detect the survival rate of PC12 cells. The PC12 cells transfected with reporter gene plasmid(pARE-Luc)were cultured as above for 24 h,luciferase(Luc)assay was used to detect the transcriptional levels of the antioxidant response element(ARE)of all groups of cells(reflected as the activity of Luc)so as to investigate the anti-injury mechanism. RESULTS:The ingredient of Z. jujuba with polysaccharide enriched could significantly increase the survival rate of PC12 cells to which oxidative damage was caused and the transcriptional level of ARE in the transfected cells. Among the flavonoid ingredients of Z. jujuba, A(30 μmol/L),B(3-30 μmol/L)and C(10-30 μmol/L)could significantly increased the survival rate of the cells,and A(30 μmol/L),B(3-30 μmol/L),C(30 μmol/L),E(30 μmol/L)and F(3-30 μmol/L)could obviously in-creased the activation level of ARE in the transfected cells. However,the nucleoside ingredients of Z. jujuba including cyclic ade-nosine monophosphate and cyclic guanosine monophosphate had no obvious effect of increasing the survival rate of PC12 cells to which oxidative damage was caused or activating the transcription of ARE in the transfected cells. CONCLUSIONS:The polysac-charide and flavonoid ingredients of Z. jujuba may be the active ingredients which account for the neuroprotective effect against oxi-dative cellular damage,and their mechanisms of action may be related to the activation of ARE transcription.

Anti-oxidative stress actions and regulation mechanisms of Keap1-Nrf2/ARE signal pathway / 国际药学研究杂志

The epoxy chloropropane Kelch sample related protein-1(Keap1)-nuclear factor erythroid-2 related factor(Nrf2)/antioxidant response element(ARE)signal pathway is of critical importance in cellular antioxidant response. The induction of down?stream phaseⅡmetabolic enzymes and antioxidant protein/enzyme offers cellular protection under oxidative stress. Research of Nrf 2 protein has gained much attention in recent years. This article reviewes Keap1-Nrf2/ARE signal pathway in three perspectives:the ba?sic structure including the structure of Nrf2,Keap1 and ARE,their involvement in anti-oxidative actions including the basic function of Keap1-Nrf2/ARE signal pathway and the downstream activation of phaseⅡmetabolic enzymes and antioxidant protein/enzyme,as well as their regulation mechanisms,such as decoupling,degradation,the latch and the hinge.

Research progress in molecular structure and function of nuclear factor erythroid 2 related factor 2 and Keap1 and regulation mechanism of signal pathways / 中国药理学与毒理学杂志

The binding of the nuclear factor erythroid 2 related factor 2(Nrf2)to the antioxidant response elements(ARE)can start the expression of batches of antioxidant proteins,anti-inflammatory factors and detoxification enzymes. Nrf2/ARE signalling plays a pivotal role in anti-inflammation and in preventing xenobiotics induced lesions. Besides involvenment in physiological processes,such as regulating nutrient metabolism,Nrf2/ARE signalling also functions in the pathogenesis of various dieases. This review outlines the strcuture,functions,and regulation of Nrf2/ARE signal pathways.