Resveratrol-treated Group Research Articles

Resveratrol, an Nrf2 activator, ameliorates aging-related progressive renal injury.

Background. Two important issues in the aging kidney are mitochondrial dysfunction and oxidative stress. An Nrf2 activator, resveratrol, is known to have various effects. Resveratrol may prevent inflammation and oxidative stress by activating Nrf2 and SIRT1 signaling. We examined whether resveratrol could potentially ameliorate the cellular condition, such as renal injury due to cellular oxidative stress and mitochondrial dysfunction caused by aging.Methods. Male 18-month-old C57BL/6 mice were used. Resveratrol (40 mg/kg) was administered to aged mice for 6 months. We compared histological changes, oxidative stress, and aging-related protein expression in the kidney between the resveratrol-treated group (RSV) and the control group (cont). We performed experiments using small-interfering RNAs (siRNAs) for Nrf2 and SIRT1 in cultured HK2 cells.Results. Resveratrol improved renal function, proteinuria, histological changes and inflammation in aging mice. Also, expression of Nrf2-HO-1-NOQ-1 signaling and SIRT1-AMPK-PGC-1α signaling was increased in the RSV group. Transfection with Nrf2 and SIRT1 siRNA prevented resveratrol-induced anti-oxidative effect in HK2 cells in media treated with H2O2.Conclusions. Activation of the Nrf2 and SIRT1 signaling pathways ameliorated oxidative stress and mitochondrial dysfunction. Pharmacological targeting of Nrf2 signaling molecules may reduce the pathologic changes of aging in the kidney.

Sonic hedgehog signaling mediates resveratrol to improve maturation of pig oocytes in vitro and subsequent preimplantation embryo development.

The beneficial effects of resveratrol on in vitro maturation (IVM) have been explained mainly by indirect antioxidant effects and limited information is available on the underlying mechanism by which resveratrol acts directly on porcine cumulus oocyte complexes (COCs). Recently, several studies reported that sonic hedgehog (SHH) signaling mediates resveratrol to exert its biological activities. Furthermore, SHH is an important signaling molecule for follicle development, oocyte maturation, and embryo development. Therefore, to elucidate the relationship between resveratrol and SHH signaling, we designed three groups: (i) control; (ii) resveratrol; and (iii) resveratrol with cyclopamine (SHH signaling inhibitor). We evaluated the effects of these agents on cumulus expansion, oocyte maturation, embryo development after parthenogenetic activation, expression levels of mRNAs in cumulus cells, oocytes and blastocysts, and protein expression in COCs. Resveratrol significantly increased the proportion of COCs exhibiting complete cumulus expansion (degree 4), oocyte nuclear maturation, cleavage and blastocyst formation rates and total cell numbers, which were blocked in the presence of cyclopamine. At the same time, a significant increase in the expression levels of mRNAs related to cumulus expansion, oocyte maturation and SHH signaling-related mRNAs and proteins from the resveratrol treatment group was also inhibited by simultaneous addition of cyclopamine. In conclusion, our results indicate that SHH signaling mediates resveratrol to improve porcine cumulus expansion, oocyte maturation, and subsequent embryo development.

Involvement of autophagy in the beneficial effects of resveratrol in hepatic steatosis treatment. A comparison with energy restriction.

Autophagy eliminates damaged cellular components. In the liver, it has been proposed that it mediates the breakdown of lipid droplets. This study aimed to compare the involvement of autophagy and the oxidative status in the effects of resveratrol and energy restriction as therapeutic tools for managing liver steatosis. In addition, potential additive or synergic effects were studied. Rats were fed a high-fat high-sucrose diet for 6 weeks and then divided into four experimental groups and fed a standard diet: a control group (C), a resveratrol-treated group (RSV, 30 mg kg-1 d-1), an energy restricted group (R, -15%), and an energy restricted group treated with resveratrol (RR). Liver triacylglycerols (TGs) were measured by Folch's method. TBARS, GSH, GSSG, GPx and SOD were assessed using commercial kits. The protein expression of beclin, atg5 and p62, as well as ratios of pSer555 ULK1/total ULK1, pSer757 ULK1/total ULK1 and LC3 II/I were determined by western blotting. Energy restriction increased the protein expression of beclin, atg5 and pSer757 ULK1/total ULK1 and LC3 II/I ratios, and reduced the protein expression of p62, thus indicating that it induced autophagy activation. The effects of resveratrol were similar but less marked than the hypocaloric diet. No differences were observed in oxidative stress determinants except for TBARS, which was decreased by energy restriction. In conclusion, resveratrol can reverse partially dietary-induced hepatic lipid accumulation, although less efficiently than energy restriction. The delipidating effect of energy restriction is mediated in part by the activation of autophagy; however, the involvement of this process in the effects of resveratrol is less clear.

Protective role of resveratrol on testicular germ cells in mice with testicular toxicity.

The aim of the present study was to investigate the possible beneficial effects of resveratrol in mice subjected to vinyl cyclohexene dieposide (VCD) -induced testicular toxicity. A total of thirty- six Swiss albino male mice aged 28-days were used in the present study. The study was composed of two stages where mice which received or did not receive VCD (320 mg/kg/day) were administered resveratrol. The animals were assigned into control and resveratrol-treated groups in the first stage and into groups of VCD- and VCD+resveratrol-treated groups in the second stage. At the end of the experiments, relative testicular weight (TW/BW) and dry/wet weight of testis (TDW/TWW) were calculated. Histological analysis by hematoxylin and eosin (H&E) staining and immunohistochemical staining by BAX and Bcl-2 were performed. Serum testosterone, LH and FSH levels were measured by a commercially available ELISA kit. Resveratrol caused a dose-dependent increase in TW/BW and decrease in TDW/TWW (p<0.05). Resveratrol at a dose of 20 mg/kg resulted in an improvement in testosterone, LH and FSH levels in mice with VCD-induced testicular toxicity (p<0.001). Resveratrol also improved apoptotic index and epithelial cell height of testicular seminipherous tubuli significantly after VCD exposure (p<0.001). Results of the present study suggest that resveratrol can be used as a protective and/or therapeutic agent particularly for cases with male infertility caused by testicular toxicity.

The Angiogenetic Effect of Resveratrol on Dermal Wound Healing in Balb/C Mice

Background: Angiogenesis has a basic role in wound healing. Vascular endothelial growth factor (VEGF) is considered as the most efficient signal that stimulates angiogenesis in wounds. Resveratrol as a natural polyphenol has enigmatic effects on VEGF-expression, angiogenesis, and granulation. Thus, the current study investigated resveratrol effects on these factors during wound healing in BALB/c mice. Methods: Sixty male BALB/c mice (2.5-month-old) were divided into 5 groups (each group n = 12). A full dermis thickness incision was placed on the dorsal skin. The study groups were topically administered 0.05% and 0.1% resveratrol, while the control groups were treated with nitrofurazone 0.2% cream (positive control), eucerine (negative control) or no treatment (sham group) twice per day for 14 days post wounding. Three animals of each group were sacrificed after anesthetizing on the post-operative days of 4, 7, 10, and 14. Therefore, the incision wounds were examined histologically and immunohistochemically using ImageJ software. Data were expressed as mean ± standard deviation (SD). Comparisons among multiple groups were performed by analysis of variance (ANOVA). Data were analyzed with SPSS version 24. Results: Compared with the control and sham groups, resveratrol administration increased VEGF-expression in a concentration-dependent manner. Results of the current study also revealed that higher granulation at wound tissue due to high VEGF expression accelerated wound healing. The mean of granulation in resveratrol-treated group was significantly higher than those of the control groups. Conclusions: The current study findings showed that resveratrol had positive effect on VEGF-expression and granulation in wound healing.

Effect of resveratrol on forelimb grip strength and myofibril structure in aged rats

To observe the effect of resveratrol on muscle mass, forelimb grip strength, myofibril structure and AMPK/sirt1 pathway in skeletal muscles of aged rats. Twenty aged (25 months old) SD rats were randomly divided into aged control group and resveratrol treatment group (10 in each group) with 10 young (6 months old) rats served as the young control group. In resveratrol treatment group, the rats were treated with resveratrol (mixed in chow) for 6 weeks. After the treatment, the mass of the gastrocnemius was measured and the sarcopenia index (SI) was calculated as the gastrocnemius mass (mg) to body weight (g) ratio. The forelimb grip strength of the rats was measured using a electronic grip strength meter, and the lengths of the sarcomere, I-band, A-band and H-zone of the myofibrils were determined by transmission electron microscopy. Compared with the young rats, the aged control rats had significantly lower SI of the gastrocnemius (P<0.05) and grip strength (P<0.05) with increased lengths of the sarcomere, A-band, I-band and H-zone (P<0.05) and lowered expressions of AMPK, P-AMPK, and sirt1 protein (P<0.05). Resveratrol treatment of the aged rats significantly increased the forelimb grip strength, reduced the lengths of sarcomere length, I-band and H-zone (P<0.05) and increased, P-AMPK, sirt1 protein expressions (P<0.05) without significantly affecting the SI (P>0.05) or the A-band length (P>0.05). Resveratrol does not improve the muscle mass but can increase the forelimb grip strength in aged rats possibly by activating AMPK/sirt1 pathway to improve the ultrastructure of the myofibrils.

The Effects of Resveratrol on Inflammation and Oxidative Stress in a Rat Model of Chronic Obstructive Pulmonary Disease

Oxidative stress and inflammation are hypothesized to contribute to the pathogenesis of chronic obstructive pulmonary disease (COPD). Resveratrol (trans-3,5,4′-trihydroxystilbene) is known for its antioxidant and anti-inflammatory properties. The study aimed to investigate the effects of resveratrol in a rat model with COPD on the regulation of oxidative stress and inflammation via the activation of Sirtuin1 (SIRTl) and proliferator-activated receptor-γ coactivator-1α (PGC-1α). Thirty Wistar rats were randomly divided into three groups: control group, COPD group and resveratrol intervention group. The COPD model was established by instilling with lipopolysaccharide (LPS) and challenging with cigarette smoke (CS). The levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) in serum were measured. The levels of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were measured. The expression levels of SIRT1 and PGC-1α in the lung tissues were examined by immunohistochemistry as well as real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) and western blotting analysis. After the treatment with resveratrol (50 mg/kg), compared with the COPD group, alleviation of inflammation and reconstruction in the small airways of the lungs were seen. Resveratrol might be correlated not only with the lower level of MDA and the higher activity of SOD, but also with the upregulation of SIRT1 and PGC-1α expression. Resveratrol treatment decreased serum levels of IL-6 and IL-8. Our findings indicate that resveratrol had a therapeutic effect in our rat COPD model, which is related to the inhibition of oxidative stress and inflammatory response. The mechanism may be related to the activation and upgrading of the SIRT1/PGC-1α signaling pathways. Thus resveratrol might be a therapeutic modality in COPD.

Protective effect of resveratrol against light-induced retinal degeneration in aged SAMP8 mice.

PurposeThe purpose of this study was to determine the protective effects of Resveratrol (RESV) on acute bright light-induced retinal degeneration in aged senescence accelerated mouse strain.MethodsTen three-month-old male SAMP8 mice (prone to aging) were randomly assigned to two experimental dietary groups: one untreated group and one RESV treatment group (n=20 eyes for each group). After 30 days of treatment, mice were exposed to intense bright light. Ten male SAMR1 mice (resistant to aging) served as control (n=20 eyes). The protective effects of RESV administration on light-induced retinal degeneration in SAMP8 strain as well as the effect of bright light damage in the retinas of SAMP8 mice were analyzed by electroretinography (ERG), retinal histology, mRNA, protein and lipid profile.Results68%-85% of a-wave amplitude and 72%-92% of b-wave amplitude were persevered by RESV in SAMP8 mice that were exposed to light damage. Also, RESV preserved their photoreceptor nuclei. mRNA expression of neuroprotective factors leukemia inhibitory factor (LIF), brain derived neurotrophic factor (BDNF), oncostatin M (OSM), cardiotrophin 1(CT-1) and cardiotrophin-like cytokine (CLC) were up-regulated 28, 8, 7, 5 and 9-fold in SAMP8 mice after RESV treatment. In addition, RESV could suppress the NF-κB pathway by down-regulating the expression of pIκB. Light damage led to increase of saturated FA, monoenoic FA, n6 PUFA and n6/n3 ratio and decrease of Docosahexaenoic acid (DHA). There was no significant difference on DHA and the ratio of n6/n3-FA between the untreated and RESV treated SAMP8 mice.ConclusionsCollectively, our study provides evidence that RESV prevents light-induced retinal damage associated with aging.

Lack of Additive Effects of Resveratrol and Energy Restriction in the Treatment of Hepatic Steatosis in Rats.

The aims of the present study were to analyze the effect of resveratrol on liver steatosis in obese rats, to compare the effects induced by resveratrol and energy restriction and to research potential additive effects. Rats were initially fed a high-fat high-sucrose diet for six weeks and then allocated in four experimental groups fed a standard diet: a control group, a resveratrol-treated group, an energy restricted group and a group submitted to energy restriction and treated with resveratrol. We measured liver triacylglycerols, transaminases, FAS, MTP, CPT1a, CS, COX, SDH and ATP synthase activities, FATP2/FATP5, DGAT2, PPARα, SIRT1, UCP2 protein expressions, ACC and AMPK phosphorylation and PGC1α deacetylation. Resveratrol reduced triacylglycerols compared with the controls, although this reduction was lower than that induced by energy restriction. The mechanisms of action were different. Both decreased protein expression of fatty acid transporters, thus suggesting reduced fatty acid uptake from blood stream and liver triacylglycerol delivery, but only energy restriction reduced the assembly. These results show that resveratrol is useful for liver steatosis treatment within a balanced diet, although its effectiveness is lower than that of energy restriction. However, resveratrol is unable to increase the reduction in triacylglycerol content induced by energy restriction.

Resveratrol inhibits apoptosis by increase in the proportion of chondrocytes in the S phase of cell cycle in articular cartilage of ACLT plus Mmx rats.

The current study was aimed to investigate the effect of resveratrol on apoptosis inhibition in chondrocytes in ACLT plus Mmx rat model. TUNEL assay revealed a markedly higher level of apoptotic chondrocytes in the cartilage of untreated ACLT plus Mmx rats. The percentage of apoptotic chondrocytes was found to be 29.5 and 40.75%, respectively at 21 and 45 days. The percentage of apoptotic chondrocytes at 21 and 45 days in resveratrol (5 mg/kg) treated ACLT plus Mmx rats was found to be 13% and 2%, respectively. Real-time PCR analysis revealed that treatment of the ACLT plus Mmx rats with resveratrol for 45 days caused a significant increase in the expression of miR-18a compared to that in untreated rats. Flow cytometry and BrdUrd incorporation assay revealed that the proportion of chondrocytes in the S phase was increased to 51.4% in resveratrol treatment group compared to 25.3% in the untreated ACLT plus Mmx rats. Western blot analysis showed that treatment of the ACLT plus Mmx rats with resveratrol decreased the expression of ATM protein kinase and GFP protein without any effect on the expression of GFP-ϒ-tubulin in chondrocytes. In addition, resveratrol treatment also led to reduction in the activity of luciferase in the chondrocytes of ACLT plus Mmx rats. Resveratrol treatment of the ACLT plus Mmx rats decreases the expression level of ATM protein and checkpoint kinase 2 (CHK2) phosphorylation in chondrocytes. H2AX and 53BP1 phosphorylation was decreased in ACLT plus Mmx rats on treatment with resveratrol for 45 days. Immunofluorescence results revealed a markedly lower level of H2AX and 53BP1 nuclear foci in the chondrocytes of ACLT plus Mmx rats treated with resveratrol. Thus resveratrol treatment of the ACLT plus Mmx rats inhibits chondrocyte apoptosis and increases proportion of cells in the S phase of cell cycle which may be through the increase in expression of miR18a. A significant relation appears between resveratrol and miR-18a expression in the chondrocytes.

Upregulation of connexin 43 and apoptosis‑associated protein expression by high glucose in H9c2 cells was improved by resveratrol via the autophagy signaling pathway.

The expression of connexin43 (Cx43) protein and the apoptotic rate of cardiomyocytes may be regulated by autophagy and associated with diabetic cardiomyopathy. It is possible that the beneficial effect of resveratrol on diabetic cardiomyocytes occurs via the autophagy pathway. However, it remains to be elucidated whether resveratrol treatment may attenuate the hyperglycemia-induced remodeling of Cx43 and apoptosis through the regulation of autophagy. H9c2 cardiac cells were incubated with 5.5 and 25 mM glucose, 25 mM glucose with chloroquine (50 µM), and 25 mM glucose with or without resveratrol (10, 25 µM) for 24 h. H9c2 cells were also incubated with 25 µM resveratrol in the presence of chloroquine (50 µM). Cell viability was determined using an MTT cell survival assay. Cytotoxicity was determined by quantification of the release of lactate dehydrogenase. The expression of Cx43, autophagic maker proteins [Beclin-1, p62 and microtubule-associated protein 1 light chain 3 (LC3)], apoptosis maker proteins (B-cell lymphoma-2 and Bcl-2 associated X protein), AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) were determined using western blotting. Resveratrol treatment led to reduced Cx43 expression levels compared with the 25 mM glucose treatment and significantly reduced the expression of apoptosis-associated proteins in H9c2 cells under hyperglycemic conditions. Autophagy was increased as indicated by the upregulation of Beclin-1 and p62 expression and the reduced LC3-II/LC3-I ratio. AMPK expression was increased, whereas mTOR expression was reduced in the resveratrol treatment groups. Treatment with chloroquine reversed effect of resveratrol. In conclusion, administration resveratrol may protect H9c2 cells against hyperglycemia-induced Cx43 upregulation and apoptosis, which may be mediated through the induction of the autophagy signaling pathway.

Effects of Hypobaric Hypoxia on Rat Retina and Protective Response of Resveratrol to the Stress.

High-altitude retinopathy represents retinal functional changes associated with environmental challenges imposed by hypobaric hypoxia, but the detailed cellular and molecular mechanism underlying this process remains unclear. Our current investigation was to explore the effect of hypobaric hypoxia on the rat retina and determine whether resveratrol has a protective efficacy on the hypoxic damage to the retina. Experiment rats were randomly grouped as the control group, hypoxia group and resveratrol intervention group. The hypoxia group and the resveratrol intervention group were maintained in a low-pressure oxygen cabin, and the resveratrol intervention group was given daily intraperitoneal injections with resveratrol. We found that hypobaric hypoxia increased thioredoxin 1 (Trx1) and thioredoxin 2 (Trx2) expression in retinas, and resveratrol treatment significantly reversed these changes (P < 0.05, P < 0.05 respectively). In comparison with controls, hypoxia upregulated the mRNA expression levels of caspase3 (P < 0.001), caspase9 (P < 0.01), heat shock protein 70 (Hsp70) (P < 0.05), heat shock protein 90 (Hsp90) (P < 0.001) and hypoxia-inducible factor-1 (HIF-1) (P < 0.05). Resveratrol administration caused a significant decrease in the gene expression of caspase3 (P< 0.001), HSP90 (P < 0.05) and HIF-1 mRNA (P < 0.01) as well as an increase in HSP70 mRNA when compared with the hypoxia group. These findings indicated that resveratrol exerted an anti-oxidative role by modulating hypoxia stress- associated genes and an anti-apoptosis role by regulating apoptosis-related cytokines. In conclusion, hypobaric hypoxia may have a pathological impact on rat retinas. The intervention of resveratrol reverses the effect induced by hypobaric hypoxia and elicits a protective response to the stress.

Resveratrol protects against lipopolysaccharide-induced cardiac dysfunction by enhancing SERCA2a activity through promoting the phospholamban oligomerization.

The bacterial endotoxin lipopolysaccharide (LPS) is a main culprit responsible for cardiac dysfunction in sepsis. This study examined whether resveratrol could protect against LPS-induced cardiac dysfunction by improving the sarcoplasmic endoplasmic reticulum Ca2+-ATPase (SERCA2a) activity. Echocardiographic parameters, cardiomyocyte contractile and Ca2+ transient properties, markers for cardiac inflammation, cell death, and oxidative stress, SERCA2a activity, and the ratios of phospholamban (PLB) monomer to oligomer were measured. Cardiac function was decreased >50% after LPS challenge (6 mg/kg for 6 h), which was improved by resveratrol. There was neither difference in plasma tumor necrosis factor-α and troponin I levels nor in infiltration of CD45+ cells in cardiac tissue between resveratrol-treated and untreated groups. In cardiomyocytes, LPS significantly decreased contractile amplitude, elongated relengthening time, diminished Ca2+ transient, reduced SERCA2a activity, and increased superoxide generation. These pathological alterations were attenuated by resveratrol treatment. Immunoblot analysis showed that LPS-treated mice had increased levels of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), and the monomer form of PLB, along with decreases in the levels of SERCA2a, the oligomer form of PLB and nuclear factor erythroid 2-related factor (Nrf-2). Resveratrol treatment upregulated SERCA2a, the oligomer form of PLB, and Nrf-2 expression and function, and downregulated MDA, 4-HNE, and the monomer form of PLB. Our data suggest that the activity of SERCA2a in endotoxemia is inhibited, possibly due to increases in the monomer form of PLB. Resveratrol protects the heart from LPS-induced injuries at least in part through promoting the oligomerization of PLB that leads to enhanced SERCA2a activity.

Efficacy of Resveratrol Supplementation against Non-Alcoholic Fatty Liver Disease: A Meta-Analysis of Placebo-Controlled Clinical Trials

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease with rising prevalence. Increasing evidence has demonstrated that resveratrol, a dietary phytochemical, is capable of attenuating NAFLD development and progression; however, results from clinical studies are inconsistent and inconclusive. Here, we conducted a meta-analysis to evaluate the efficacy of resveratrol on NAFLD, using several parameters to provide new insights for clinical application. We systematically searched EMBASE, PubMed, Science Citation Index, Elsevier, and Cochrane Library databases for studies published up to date (July 2016), in English, to identify and screen eligible, relevant studies. Either a fixed-effect model or random model was used to estimate mean difference (MD) and 95% confidence intervals (CIs) for the effect of resveratrol on NAFLD. Four randomized, double-blinded, placebo-controlled trials involving 156 patients were included in the meta-analysis. Levels of low-density lipoprotein (MD = 0.47, 95% CI: 0.21, 0.74, P < 0.05) and total cholesterol (MD = 0.49, 95% CI: 0.18, 0.80, P < 0.05) were higher in the resveratrol treatment groups than in placebo control groups, whereas other parameters were not altered. Overall, this study indicates that resveratrol treatment has negligible effects on attenuating NAFLD, given the small improvement in NAFLD features. More high-quality clinical trials of resveratrol for NAFLD are required to confirm these results.

Abstract 5043: Molecular mechanism of resveratrol induced cell death in multidrug resistance prostate cancer

Abstract In order to understanding the molecular mechanisms of drug resistance as well as enhancing the efficacy of docetaxel we established docetaxel-resistant prostate cancer (PCa) cells. The IC50 for docetaxel in PCa resistant cells was about 50-fold higher than parental PCa cells. In the current study we used resveratrol (RES), a natural compound with chemo preventive potential to test its ability to enhance the effectiveness of docetaxel on PCa as well as to explore the mechanism of acquired docetaxel resistance. PCa (PC3, C4-2B and DU145) cell lines treated with different dose of RES or DTX alone or in combination followed by analyzed cell proliferation (MTT assay), apoptosis (flow-cytometric analysis of annexin V/propidium iodide-stained cells and western blot methods).The expression of ABC transporter markers in the development of docetaxel resistance was examined using RT-PCR. Our result shows that the expression of 18 ABC transporter genes were down regulated in PCa cells at 48 and 72 hrs in RES treatment group. The up regulations of pro-apoptotic proteins (Bax, Bad, Bim) and down regulation of anti-apoptotic protein (Bcl2, Mcl1) further confirmed the effectiveness of RES or DTX alone or in combination with DTX. In conclusion these studies suggest that RES inhibits ABC gene expression and resensitizes docetaxel resistant PCa cells to DTX treatment with enhancing apoptotic cell death. Citation Format: Santosh K. Singh, Saswati Banerjee, James W. Lillard, Rajesh Singh. Molecular mechanism of resveratrol induced cell death in multidrug resistance prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5043.

Early proapoptotic role of thioredoxin-interacting protein after subarachnoid hemorrhage: an experimental study

Objectives To detect the expression of thioredoxin-interacting protein (TXNIP) and its related apoptosis factors after subarachnoid hemorrhage (SAH) and to investigate the role and its mechanism of TXNIP in early brain injury after SAH. Methods A rat SAH model was induced by intravascular puncture. A sham operation group, a SAH group, a resveratrol intervention control group, and a resveratrol intervention group were set up. Immunofluorescence staining was used to observe the expression of neuronal TXNIP. The fluorescent TUNEL assay was used to detect cell apoptosis and TXNIP colocalization. Western blot was used to detect the expression changes of TXNIP, p-ASK-1, Caspase-3, Bax, and Bcl-2 at each time point before and after the intervention within 72 h after SAH. TUNEL assay was used to detect the cortical and hippocampal cell apoptosis before and after intervention, and the changes of behavior and brain edema were assessed before and after intervention at the same time. Results The results of immunofluorescence staining showed that TXNIP was mainly expressed in neuronal cytoplasm. Fluorescent TUNEL assay found that there was colocalization between TXNIP and subcortical apoptotic cells. Compared with the sham operation group, TXNIP expression increased gradually at 12 h after SAH. The expression at each time point early after hemorrhage was higher than that of the sham operation group (all P<0.05). At the same time, the expression levels of p-ASK-1, Caspase-3, and Bax were increased, and the expression of Bcl-2 was decreased. There were significant differences (all P<0.05). After resveratrol intervention, TXNIP and p-ASK-1, Caspase-3, and Bax were downregulated (all P<0.05). The results of TUNEL assay showed that the apoptotic cells decreased after intervention (P<0.05). Behavioral score and cerebral edema were also improved (all P<0.05). Conclusions Early TXNIP expression began to increase after SAH. TXNIP might aggravate early brain damage after SAH through its proapoptotic effect, and resveratrol could improve brain cell death and the prognosis in rats by inhibiting TXNIP. The downregulation of the TXNIP expression might become a new treatment measure at early stage after SAH. Key words: Subarachnoid hemorrhage; Thioredoxin-interacting protein; Early brain injury; Apoptosis; Rats

Efficiacy of resveratrol and quercetin after experimental spinal cord injury.

The aim of this study was to investigate the effect of natural antioxidants resveratrol and quercetin on oxidative stress and secondary cell damage in rats with acute spinal cord injury. In this experimental study, 42 male Sprague-Dawley rats were used. Spinal cord injury was performed with clip compression method at level of T4-5. The study was conducted using 6 groups: control, trauma, trauma and solvent, trauma and resveratrol, trauma and quercetin, and trauma with combined resveratrol and quercetin. All rats were euthanized 48 hours after the procedure. Effects of resveratrol and quercetin on serum and tissue total antioxidant capacity and paraoxanase activity level were examined. Compared to trauma group, there was a significant increase in total antioxidant capacity and paraoxanase activity level in resveratrol, quercetin, and combined treatment groups. There was no significant difference between resveratrol and quercetin groups with regard to total antioxidant capacity and paraoxanase activity level. Total antioxidant capacity and paraoxanase activity level were significantly higher in solvent group than trauma group. In histopathological evaluation, there was a decrease in polymorphonuclear leukocyte infiltration in solvent, resveratrol, quercetin, and combined treatment groups. Biochemical and histological staining results of present study showed that resveratrol and quercetin may be effective in preventing secondary damage in spinal cord injury.

Effect of resveratrol on myocardial energy metabolism in sepsis rats

To investigate the influence of resveratrol (RES) on myocardial energy metabolism in sepsis rats and its mechanism. Twenty Sprague-Dawley (SD) rats were divided into four groups according to the random number table, 5 rats in each group. The sepsis model was reproduced by intraperitoneal injection of lipopolysaccharide (LPS) 10 mg/kg, and the rats in sham group were injected intraperitoneally with the same amount of saline. The rats in RES treatment group (RES group) were injected RES 8 mg/kg 10 minutes before LPS injection, and those in RES combined with the silent information regulator 1 (sirti) inhibitor group (RES + sirtinol group) were injected sirtinol 1 mg/kg followed by RES 8 mg/kg 10 minutes before LPS injection. The rats were sacrificed 6 hours later, and the heart was harvested. The myocardial ultrastructure was observed by transmission electron microscope. The expression of sirt1 protein was detected by Western Blot. The cytochrome C oxidase (CCO) activity was determined by ultraviolet spectrophotometry. The content of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) were detected by high-performance liquid chromatography (HPLC). Under transmission electron microscopy, the mitochrondria in myocardium in sham group was normal, and mitochrondria was swollen and derangement in LPS group and RES + sirtinol group, but it was not significant in RES group. Compared with sham group, the siit1 protein expression in LPS group was decreased (gray value: 0.602 ± 0.038 vs. 0.902 ± 0.037, P < 0.05), the CCO activity was declined (U/mg: 0.344 ± 0.019 vs. 0.600 ± 0.023, P < 0.05), the contents of ATP, ADP, and AMP were decreased [ATP (µg/g): 89.958 ± 7.570 vs. 157.460 ± 6.737, ADP (µg/g): 164.658 ± 6.742 vs. 251.608 ± 5.191, AMP (µg/g): 179.926 ± 7.303 vs. 276.262 ± 5.546 all P < 0.05]. Compared with LPS group, the sirt1 protein expression in RES group was increased (gray value: 0.874 ± 0.017 vs. 0.602 ± 0.038, P < 0.05), the CCO activity was increased (U/mg: 0.574 ± 0.013 vs. 0.344 ± 0.019, P < 0.05), the contents of ATP, ADP, and AMP were increased [ATP (µg/g): 97.942 ± 11.257 vs. 147.686 ± 8.853, ADP (µG/G): 168.888 ± 8.965 VS. 245.860 ± 7.111, AMP (µg/g): 175.498 ± 6.993 vs. 271.260 ± 6.658, all P < 0.05].

Resveratrol alleviates diabetes-induced testicular dysfunction by inhibiting oxidative stress and c-Jun N-terminal kinase signaling in rats

Diabetes adversely affects reproductive functions in humans and animals. The present study investigated the effects of Resveratrol on diabetes-induced alterations in oxidative stress, c-Jun N-terminal kinase (JNK) signaling and apoptosis in the testis. Adult male Wistar rats (13–15weeks; n=6/group) were segregated into 1) normal control, 2) Resveratrol-treated (5mg/kg; ip; given during last 3weeks), 3) Streptozotocin-induced diabetic and, 4) Resveratrol-treated diabetic groups, and euthanized on day 42 after the confirmation of diabetes. Resveratrol did not normalize blood glucose levels in diabetic rats. Resveratrol supplementation recovered diabetes-induced decreases in reproductive organ weights, sperm count and motility, intra-testicular levels of superoxide dismutase, catalase, and glutathione peroxidase and an increase in 4-hydroxynonenal activities (P<0.05). Resveratrol also recovered diabetes-induced increases in JNK signaling pathway proteins, namely, ASK1 (apoptosis signal-regulating kinase 1), JNKs (46 and 54kDa isoforms) and p-JNK to normal control levels (P<0.05). Interestingly, the expression of a down-stream target of ASK1, MKK4 (mitogen-activated protein kinase kinase 4) and its phosphorylated form (p-MKK4) did not change in experimental groups. Resveratrol inhibited diabetes-induced increases in AP-1 (activator protein-1) components, c-Jun and ATF2 (activating transcription factor 2), but not their phosphorylated forms, to normal control levels (P<0.05). Further, Resveratrol inhibited diabetes-induced increase in cleaved-caspase-3 to normal control levels. In conclusion, Resveratrol alleviates diabetes-induced apoptosis in testis by modulating oxidative stress, JNK signaling pathway and caspase-3 activities, but not by inhibiting hyperglycemia, in rats. These results suggest that Resveratrol supplementation may be a useful strategy to treat diabetes-induced testicular dysfunction.

Effects of long-term resveratrol-induced SIRT1 activation on insulin and apoptotic signalling in aged skeletal muscle.

Activation of Foxo1 is known to promote apoptosis and disturbances to insulin signalling. However, their modulating roles in aged skeletal muscle are not clear. The present study tested the hypothesis that long-term (i.e. 8 month) resveratrol supplementation would improve physical traits including exercise capacity and basal voluntary activity of aged mice and modulate insulin/apoptotic signalling in aged skeletal muscle. This study also examined whether these resveratrol-associated alterations would involve orchestration of the SIRT1-Foxo1 signalling axis. Two-month-old SAMP8 mice were randomly assigned to young, aged and aged with resveratrol treatment (AR) groups. The AR mice were supplemented with 4.9 mg(-1) kg(-1) day(-1) resveratrol for 8 months. All animals were subject to endurance capacity test and voluntary motor behaviour assessment. The lateral gastrocnemius muscle tissues were harvested for further analyses. Long-term resveratrol treatment significantly alleviated the age-associated reductions in exercise capacity and voluntary motor behaviour. The protein content, but not the deacetylase activity of SIRT1 was increased with concomitant elevations of p300 acetylase and acetylation of Foxo1 in aged muscle. The aged muscle also manifested signs of impaired insulin signalling including attenuated phosphorylation of Akt, activity of pyruvate dehydrogenase and membrane trafficking of GLUT4 and elevated levels of phosphorylated IRS1 and iNOS and apoptotic activation measured as Bim, p53 and apoptotic DNA fragmentation. Intriguingly, all these age-related adverse changes were mitigated with the activation of SIRT1 deacetylase activity after long-term resveratrol treatment. These data suggest that modulation of the SIRT1-Foxo1 axis by long-term resveratrol treatment enhances physical traits and alleviates the unfavourable changes in insulin and apoptotic signalling in aged muscle.