Resveratrol reduces matrix metalloproteinase-2 activity induced by oxygen-glucose deprivation and reoxygenation in human cerebral microvascular endothelial cells

Resveratrol has an Overall Neuroprotective Role in Ischemic Stroke: A Meta-Analysis in Rodents

Background: Resveratrol, a natural polyphenolic phytoalexin, is broadly presented in dietary sources. Previous research has suggested its potential neuroprotective effects on ischemic stroke animal models. However, these results have been disputable. Here, we conducted a meta-analysis to comprehensively evaluate the effect of resveratrol treatment in ischemic stroke rodent models.

Objective: To comprehensively evaluate the effect of resveratrol treatment in ischemic stroke rodent models.

Methods: A literature search of the databases Pubmed, Embase, and Web of science identified 564 studies that were subjected to pre-defined inclusion criteria. 54 studies were included and analyzed using a random-effects model to calculate the standardized mean difference (SMD) with corresponding confidence interval (CI).

Results: As compared with controls, resveratrol significantly decreased infarct volume (SMD −4.34; 95% CI −4.98 to −3.69; p < 0.001) and the neurobehavioral score (SMD −2.26; 95% CI −2.86 to −1.67; p < 0.001) in rodents with ischemic stroke. Quality assessment was performed using a 10-item checklist. Studies quality scores ranged from 3 to 8, with a mean value of 5.94. In the stratified analysis, a significant decrease of infarct volume and the neurobehavioral score was achieved in resveratrol sub-groups with a dosage of 20–50 mg/kg. In the meta-regression analysis, the impact of the delivery route on an outcome is the possible source of high heterogeneity.

Conclusion: Generally, resveratrol treatment presented neuroprotective effects in ischemic stroke models. Furthermore, this study can direct future preclinical and clinical trials, with important implications for human health.

Usefulness of resveratrol supplementation in decreasing cardiometabolic risk factors comparing subjects with metabolic syndrome and healthy subjects with or without obesity: meta-analysis using multinational, randomised, controlled trials

Introduction

Resveratrol (RES), a natural polyphenolic compound, has been linked to some beneficial effects against cardiovascular disease (CVD).

Material and methods

We conducted a systematic search to conduct a meta-analysis on cardiometabolic risk factors modulated by RES targeting patients with metabolic syndrome (Met-S) and Obese/Healthy (O/H) subjects. The PICO (Patient, Intervention, Comparison, Outcome) research question was: Does RES among patients with Met-S and O/H subjects reduce the cardiometabolic risk? The first group was affected with MetS, which is defined as a clustering of abdominal obesity, dyslipidaemia, hyperglycaemia, and hypertension in a single individual. The second group was composed of 'obese/healthy' individuals, i.e. healthy subjects with or without obesity. We performed a literature search of MEDLINE/ PubMed, Scopus, and Google Scholar for randomised, controlled trials (RCT) that estimated the effects of RES on cardiometabolic risk factors.

Results

We found 780 articles, of which 63 original articles and reviews were identified. Data from 17 well-conducted RCT studies, comprising 651 subjects, were extracted for analysis. Overall, RES had a significant influence on Homeostatic Model Assessment-Insulin Resistance (HOMA-IR), resulting in a mean difference of -0.520665 (95% CI: -1.12791; -0.01439; p = 0.00113). In Met-S, RES significantly reduced glucose, low-density lipoprotein-cholesterol (LDL-C), and total cholesterol (T-Chol) as detected by the mean difference of -1.069 (95% CI: -2.107, -0.032; p = 0.043), -0.924 (95% CI: -1.804, -0.043; p = 0.040), and -1.246 (95% CI: -2.314, -0.178; p = 0.022), respectively.

Conclusions

Despite some heterogeneity in the populations, RES supplementation seems to improve cardiometabolic health, decreasing some risk factors (HOMA-IR, LDL-C, and T-Chol) associated with CVD.

Biospecific isolation and characterization of angiogenesis-promoting ingredients in Buyang Huanwu decoction using affinity chromatography on rat brain microvascular endothelial cells combined with solid-phase extraction, and HPLC-MS/MS

Buyang Huanwu decoction (BHD) was reported to exert angiogenesis-promoting effects, but its active ingredients remain unknown. In this study, we developed a method to screen potential angiogenesis-promoting compounds in BHD, which involved biospecific isolation using live rat brain microvascular endothelial cells (rBMECs) and characterization using solid-phase extraction (SPE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Six compounds showed binding affinity to rBMECs and were further identified as 6-hydroxykaempferol-di-O-glucoside, paeoniflorin, calycosin-7-O-β-D-glucoside, galloylpaeoniflorin, formononetin-7-O-β-D-glucoside, and (3R)-7,2'-hydroxy-3',4'-dimethoxy-isoflavan. The results indicated that five of them except 6-hydroxykaempferol-di-O-glucoside showed a protective effect against oxygen glucose deprivation/reperfusion injury in rBMECs and upregulated the secretion of vascular endothelial growth factor and basic fibroblast growth factor, suggesting a mechanism underlying their angiogenic activity. Our findings suggest that biospecific live cell-based isolation combined with SPE and HPLC-MS/MS is an effective method for screening potential bioactive components in traditional Chinese medicines.

Resveratrol Preconditioning Protects Against Cerebral Ischemic Injury via Nuclear Erythroid 2-Related Factor 2

BACKGROUND AND PURPOSE

Nuclear erythroid 2 related factor 2 (Nrf2) is an astrocyte-enriched transcription factor that has previously been shown to upregulate cellular antioxidant systems in response to ischemia. Although resveratrol preconditioning (RPC) has emerged as a potential neuroprotective therapy, the involvement of Nrf2 in RPC-induced neuroprotection and mitochondrial reactive oxygen species production after cerebral ischemia remains unclear. The goal of our study was to study the contribution of Nrf2 to RPC and its effects on mitochondrial function.

METHODS

We used rodent astrocyte cultures and an in vivo stroke model with RPC. An Nrf2 DNA binding ELISA and protein analysis via Western blotting of downstream Nrf2 targets were performed to determine RPC-induced activation of Nrf2 in rat and mouse astrocytes. After RPC, mitochondrial function was determined by measuring reactive oxygen species production and mitochondrial respiration in both wild-type and Nrf2-/- mice. Infarct volume was measured to determine neuroprotection, whereas protein levels were measured by immunoblotting.

RESULTS

We report that Nrf2 is activated by RPC in rodent astrocyte cultures, and that loss of Nrf2 reduced RPC-mediated neuroprotection in a mouse model of focal cerebral ischemia. In addition, we observed that wild-type and Nrf2-/- cortical mitochondria exhibited increased uncoupling and reactive oxygen species production after RPC treatments. Finally, Nrf2-/- astrocytes exhibited decreased mitochondrial antioxidant expression and were unable to upregulate cellular antioxidants after RPC treatment.

CONCLUSIONS

Nrf2 contributes to RPC-induced neuroprotection through maintaining mitochondrial coupling and antioxidant protein expression.

Resveratrol down-regulates a glutamate-induced tissue plasminogen activator via Erk and AMPK/mTOR pathways in rat primary cortical neurons

Resveratrol (3,5,4'-trihydroxy-trans-stilbene, RSV) is a polyphenolic compound present in a variety of plant species (including grapes) that produces a myriad of biological activities including anti-inflammatory, antioxidant and neuroprotective effects. In this study, we investigate the effects of resveratrol on the basal and glutamate-stimulated expression and activity of a tissue plasminogen activator (tPA) that plays neuromodulatory or neurotoxic roles in many different neurological situations. Under basal conditions, resveratrol decreased the tPA expression and activity without affecting the tPA mRNA level in rat primary cortical neurons. RSV induced AMPK phosphorylation and inhibited mTOR phosphorylation. Inhibition of AMPK phosphorylation using compound C prevented resveratrol-induced down-regulation of tPA activity. This suggested that AMPK/mTOR-dependent translational inhibition contributes to the down-regulation of the tPA. Under glutamate-stimulated conditions of rat primary cortical neurons, tPA activity and expression were increased along with increased tPA mRNA expression but afterward treatment of RSV inhibited the glutamate-induced increase in tPA activity and expression and tPA mRNA expression. Glutamate stimulation induced activation of Akt and MAPK pathways as well as mTOR which were inhibited by RSV. Interestingly, the Erk pathway inhibitor U0126, but neither PI3K-Akt inhibitor LY294002 nor p38 inhibitor SB203580, mimicked the inhibitory action of RSV on glutamate-induced tPA up-regulation. This suggested the essential role of Erk in the transcriptional up-regulation of tPA expression, which is targeted by RSV. Glutamate stimulation induced neuronal cell death as determined by PI staining and MTT assay. However, RSV protected the cultured rat primary cortical neurons from glutamate-induced cell death as paralleled with the changes in tPA expression. These results suggested that RSV can modulate tPA activity under basal and stimulated conditions by both translational and transcriptional mechanisms. The regulation of the tPA by RSV provides additional therapeutic targets on top of the growing number of molecular substrates of RSV's action in the brain.