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Objective:To investigate the effects and potential mechanism of vitamin D supplementation on testicular function in aging rats induced by D-galactose.Methods:The aging rats were induced by D-galactose with subcutaneous injection. The animals were randomly divided into 6 groups: aging rats (DG), aging rats with low-dose vitamin D supplementation (LD), aging rats with high-dose vitamin D supplementation (HD), normal control rats(NC), normal rats with low-dose vitamin D supplementation(LN), normal rats with high-dose vitamin D supplementation (HN). The body weight, testicular weight, serum testosterone concentrations and sperm quality of the rats in each group were measured. The testis morphological changes were detected using light microscopy. The activity of superoxide dismutase (SOD) and level of malondialdehyde(MDA) were determined with spectrophotometer. The expression levels of Nrf2, GCLC, SOD2 and VDR in testis were detected by western blot.Results:At baseline, compared with NC group, testicular weight, serum testosterone level, SOD activity, Nrf2, GCLC and SOD2 expression levels were significantly decreased in DG group, while MDA level was significantly increased. After vitamin D supplementation, testicular weight, testosterone levels and SOD activity in both of HD and LD groups were significantly increased, while the MDA level was significantly decreased. The expression levels of Nrf2, GCLC, SOD2 and VDR were significantly increased.Conclusion:Vitamin D supplementation may enhance the testicular antioxidant capacity through activating Nrf2-ARE signaling pathway, and improve the testicular function in D-galactose-induced aging rats.
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OBJECTIVE@#To observe the effect of moxibustion on oxidative stress injury of nigrostriatal system in rats with Parkinson's disease (PD) based on nuclear factor erythroid 2-related factor (Nrf2)/antioxidant response element (ARE) pathway, and to explore its mechanism.@*METHODS@#A total of 48 SD rats were randomized into a blank group, a sham-operation group, a model group and a moxibustion group, 12 rats in each group. Unilateral two-point injection with 6-hydroxydopamine (6-OHDA) was adopted in the model group and the moxibustion group to establish the PD model; the operation manipulation in the sham-operation group was the same as the model group and the moxibustion group, and the same volume of 0.9% sodium chloride solutions was given by unilateral two-point injection. Moxibustion was adopted at "Baihui" (GV 20) and "Sishencong" (EX-HN 1) in the moxibustion group for 20 min, once a day, 6 times a week for 6 weeks. No intervention was given in the other 3 groups. Morphology of right mesencephalon substantia nigra was observed by HE staining, the expression of tyrosine hydroxylase (TH) in right mesencephalon substantia nigra was detected by immunohistochemistry method, the expression of reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), and glutathione peroxidase (GSH-Px) in corpus striatum was detected by colorimetry method, and the expression of Nrf2 and heme oxygenase-1 (HO-1) proteins was detected by Western blot in the 4 groups.@*RESULTS@#Clear tissue structure and complete dopaminergic neurons of right mesencephalon substantia nigra were observed in the blank group and the sham-operation group; unclear tissue structure, decreased and swelling dopaminergic neurons were observed in the model group; compared with the model group, more neurons were observed and the swelling of cyton was reduced in the moxibustion group. Compared with the sham-operation group, the expression of TH in right mesencephalon substantia nigra was decreased in the model group (<0.01); compared with the model group, the expression of TH in right mesencephalon substantia nigra was increased in the moxibustion group (<0.05). Compared with the sham-operation group, the expression of ROS, MDA was increased (<0.01), the expression of GSH, GSH-Px, Nrf2 and HO-1 was decreased in the model group (<0.01, <0.05); compared with the model group, the expression of ROS, MDA was decreased (<0.05, <0.01), the expression of GSH, GSH-Px, Nrf2 and HO-1 was increased in the moxibustion group (<0.05, <0.01).@*CONCLUSION@#Moxibustion can alleviate oxidative stress injury of nigrostriatal system in rats with Parkinson's disease by activating the Nrf2/ARE pathway, and protect the dopamine neurons.
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OBJECTIVE To investigate the early events of norcantharidin (NCTD) induced cell apoptosis and cell cycle arrest, the variation of reactive oxygen species (ROS) and the NF-E2-relate? dactor 2/antioxidant response element(Nrf2/ARE) pathway in human HepG2 cells. METHODS The cyto?toxicity was measured by MTT assay. Apoptosis and cell cycle was analyzed by flow cytometry. The intra toxicity ROS production was evaluated by flow cytometry analysis with DCFH-DA probe and the effect of NCTD on Nrf2/ARE pathway was detected by luciferase assay in HepG2C8 cells under the same condition. The mRNA expression of heme oxygenase-1(HO-1) and NAD(P)H: quinone oxidoreductase 1(NQO1) antioxidase gene in Nrf2/ARE pathway downstream was evaluated by quantitative real-time PCR. RESULTS No significant cytotoxicity was detected after HepG2 cells were treated with NCTD 30, 60 and 120 μmol · L- 1 for 3 and 6 h, but cellular viability was inhibited significantly by NCTD 30, 60 and 120μmol·L-1 for 24, 48 and 72 h(P<0.01). Cell apoptosis and G2/M phase arrest occurred after HepG2 cells were treated with NCTD 60μmol · L-1 for 12, 24 and 48 h. The percentage of apoptosis increased from (4.00 ± 1.98)%to (12.10 ± 1.70)%for 12 h, from (4.05 ± 0.21)%to (31.8 ± 6.50)%for 24 h, and from (3.90 ± 0.85)% to (33.30 ± 1.41)% for 48 h, respectively. The percentage of G2/M phase increased from (16.51 ± 1.58)% to (40.89 ± 0.18)% for 12 h, from (16.99 ± 1.32)% to (55.29 ± 3.99)% for 24 h, and from (14.45 ± 0.59)% to (50.66 ± 5.88)% for 48 h, respectively. Compared with cell control group, the percentage of G1 phase had a significant decrease in the group with NCTD treated at different time points(P<0.01). No significant change in ROS in HepG2 cells was detected after the treatment with NCTD 30, 60 and 120μmol · L-1 for 3, 6 and 12 h. Nrf2/ARE pathway in HepG2C8 cells was activated by NCTD 30, 60 and 120μmol·L-1 for 6 and 12 h. mRNA expression of HO-1 and NQO1 had a signifi?cant activation in HepG2 cells after treatment with NCTD 30, 60 and 120 μmol · L-1 for 6 and 12 h (P<0.05). CONCLUSION NCTD can activate Nrf2/ARE pathway in the early stage in HepG2 cells, which may inhibit the intracellular ROS production in the early stage. Activation of ROS may not be the main event in NCTD induced HepG2 cell apoptosis and G2/M phase arrest.
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This study was conducted to test the effects of schizandrin B (Sch B) on clozapine (CLZ) induced chronic liver injury in mice and the mechanism of action, and this may provide a new approach for clinical prevention of CLZ-induced side effects. The CLZ was given to mice for three weeks alone or co-administration with Sch B. The changes of alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and antioxidation indexes superoxide dismutase (SOD), malonic dialdehyde (MDA), glutathione (GSH) and liver histological evaluation were determined. Expression of Nrf2 was assayed in hepatic cells by immunohistochemical staining and Western blotting. The changes of relative gene expression of NAD(P)H:quinone oxidoreductase l (NQO1) and heme oxygenase 1 (HO-1) were assayed by real-time Q-PCR. The results showed that pretreatment with a lower dosage of Sch B (25, 50 mg·kg-1) prevented CLZ-induced liver injury as indicated by the reduced levels of ALT, AST and ALP, and the preserved activities of SOD, GSH and inhibiting MDA. It was shown that Sch B could up-regulate Nrf2 expression leading to nuclear accumulation of Nrf2 to induce oxidative response genes such as NQO1 and HO-1. These results suggest that Sch B could protect against liver injury induced by CLZ via the activation of the Nrf2/ARE signal pathway in a dose-dependent manner.
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Epigallocatechin-3-gallate (EGCG) is not only the most active component of green tea, but the main object in green tea research. Numerous studies have shown that EGCG has cellular protec-tion functions, such as antioxidization, scavenging free radical , anti-cancer and antiapoptotic proper-ties. It has also been proved that EGCG could activate several signaling pathways. Nuclear factor erythroid-2p45 related factor 2/antioxidant response element (Nrf2/ARE) pathway is a key way to main-tain the redox homeostasis by regulating phase Ⅱ detoxification enzymes, and anti-inflammatory proteins. Recent studies have shown that EGCG plays an inportant role in the activation of Nrf2/ARE pathway in urinary, respiratory, cardiovascular, digestive systems. This review summarizes the research progress in EGCG as an activator of Nrf2/ARE signaling pathway, and provides reference for further research and exploitation of EGCG as potential medicine.
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Objective In the study,the effect of berberine on Diabetic Nephropathy (DN) via oxidative stress was studied.Methods The DN model mice was administered with metformin (0.2g/kg),low-dose berberine (0.036 g/kg),middle-dose berberine (0.072g/kg) and high-dose berberine (0.144g/kg) for 8 weeks.After that,the fasting glucose,insulin,serum creatinine,urea nitrogen,Reactive Oxidative Species (ROS),Superoxide Dismutase (SOD),Kelch-like ECH-associated protein 1 (Keap1) 、Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and NADPH oxidase 4 (NOX4),24h urine protein,etc were measured.Results Berberine could significantly decrease the fasting blood glucose levels,increase the insulin production,and reduce the levels of 24 h urine protein,serum urea nitrogen,creatinine,improve SOD and Nrf2,decrease ROS,Keap1and NOX4.Conclusion Berberine has the protactive effects in DN mice via the Keap-Nrf2/ARE pathway,and middle/high-dose berberine was much better.The mechanism may be related to the alleviated of the oxidative stress.
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Soy isoflavones exhibit various biological activities, such as antioxidant, anti-tumor, anti-inflammatory, and cardiovascular protective effects. The present study was designed to investigate the effects of sixteen synthesized 3-amino-2-hydroxypropoxy genistein derivatives on cell proliferation and activation of Nrf2 (Nuclear factor erythroid 2-related factor 2)/ARE (antioxidant response elements) pathway in human cancer cell lines. Most of the tested compounds exerted greater cytotoxic activity than genistein, as measured by MTT assay. Moreover, compound 8c showed the highest ARE-luciferase reporter activity among the test compounds. It strongly promoted Nrf2 nuclear translocation and up-regulated the expression of total Nrf2 and downstream targets NQO-1 and HO-1 at protein level. The present study may provide a basis for the application of isoflavone derivatives as Nrf2/ARE pathway inducers for cancer therapy and cancer prevention.
Subject(s)
Humans , Antioxidant Response Elements , Cell Line, Tumor , Cell Proliferation , Genistein , Pharmacology , Therapeutic Uses , Heme Oxygenase-1 , Metabolism , Isoflavones , NF-E2-Related Factor 2 , Metabolism , Neoplasms , Drug Therapy , Metabolism , Signal Transduction , Glycine max , Chemistry , Up-RegulationABSTRACT
Objective To investigate the effects of Nrf2/ARE pathway activator upregulating the expression of phase Ⅱ detoxifcation enzymes and antioxidant enzymes in islet B cell on its morphological structure in type 2 diabetic rats.Methods Type 2 diabetic rats were divided into diabetes model group (DM group),and tertiary-Butylhydroquinone intervention group(tBHQ group).At the same time,the normal control group (NC group)was set up.All rats were killed after eight-week continuous intervention.Fasting blood glucose (FBG) and fasting insulin (FINS) level were determined.Morphological structure of islet cells and apoptosis were observed.ELISA was used to determine MDA,TNF-α and T-SOD levels in serum and pancreatic tissues and Western blot was used to detect the protein expression levels of total Nrf2 and nulear Nrf2 in pancreatic tissues.Results Compared with NC group,FBG and FINS levels significantly increased and decreased in DM group respectively (all P=0.000).Compared with DM group,FBG and FINS levels significantly decreased and increased in tBHQ group respectively (all P=0.000).Compared with NC group,the number of islet cells significantly decreased and swelling,necrosis and apoptosis occurred in DM group.Islet cells in tBHQ group were significantly better than those in DM group.Compared with NC group,MDA and TNF-α levels in serum and pancreatic tissue significantly increased and TSOD levels significantly decreased in DM group (all P=0.000).Compared with DM group,MDA and TNF-α levels in serum and pancreatic tissue significantly decreased and T-SOD levels significantly increased in DM group(all P=0.000).Total Nrf2 and nulear Nrf2 in protein expression in DM group were significantly lower of than those in NC group (P()=0.000,P nulear Nrf2=0.006).Rats in tBHQ group had significantly higher protein expression of total Nrf2 and nulear Nrf2 than in DM group (all P=0.000).Conclusions Activating Nrf2/ARE pathway can reduce injury of oxidative stress and chronic inflammation on islet B cells further through upregulating the expression of phase Ⅱ detoxifying enzymes and antioxidant enzymes in islet B cells.
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Objective To explore the protective effects of quercetin on damage induced by oxidative stress and to clari?fy its molecular mechanism. Methods Chang liver cell cultures were randomly divided into control groups, H2O2 group and 3 doses of quercetin groups. Cell survival rate was detected with MTT. Cell apoptotic rate was measured by FACS(Fluores?cence-activated cell sorting). Intracellular reactive oxygen species (ROS) level in Chang liver cells were tested by flow cy?tometer. The DCF fluorescence intensity of DCFH-DA-stained intracellular ROS was observed by fluorescence microscope. The levels of malondialdehyde (MDA), superoxide dismutase(SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined in liver cells using commercial available kits. The expression of Nrf2 were detected by Western blot. Re?sults Compared with control, cell survival rate and levels of SOD, CAT and GSH-Px decreased significantly in H2O2 group (P < 0.05 ),while cell appotosis rate, content of MDA and mean fluorescence intensity(MFI) increased in H2O2 group (P <0.05). In comparison with H2O2, expression of Nrf2 protein was higher in all three quercetin treatment groups (P<0.05). Con?clusion Quercetin protected Chang liver cells from H2O2-induced oxidative stress, which may be caused by the increased ex?pressions of down stream antioxidant genes via activating the Nrf2-ARE signaling pathway.