Resveratrol inhibits matrix metalloproteinases to attenuate neuronal damage in cerebral ischemia: a molecular docking study exploring possible neuroprotection

A comprehensive review on the neuroprotective potential of resveratrol in ischemic stroke

Stroke is the second leading cause of death and the third leading cause of disability worldwide. Globally, 68 % of all strokes are ischemic, with 32 % being hemorrhagic. Ischemic stroke (IS) poses significant challenges globally, necessitating the development of effective therapeutic strategies. IS is among the deadliest illnesses. Major functions are played by neuroimmunity, inflammation, and oxidative stress in the multiple intricate pathways of IS. Secondary brain damage is specifically caused by the early pro-inflammatory activity that follows cerebral ischemia, which is brought on by excessive activation of local microglia and the infiltration of circulating monocytes and macrophages. Resveratrol, a natural polyphenol found in grapes and berries, has shown promise as a neuroprotective agent in IS. This review offers a comprehensive overview of resveratrol's neuroprotective role in IS, focusing on its mechanisms of action and therapeutic potential. Resveratrol exerts neuroprotective effects by activating nuclear factor erythroid 2-related factor 2 (NRF2) and sirtuin 1 (SIRT1) pathways. SIRT1 activation by resveratrol triggers the deacetylation and activation of downstream targets like peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) and forkhead box protein O (FOXO), regulating mitochondrial biogenesis, antioxidant defense, and cellular stress response. Consequently, resveratrol promotes cellular survival and inhibits apoptosis in IS. Moreover, resveratrol activates the NRF2 pathway, a key mediator of the cellular antioxidant response. Activation of NRF2 through resveratrol enhances the expression of antioxidant enzymes, like heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO1), which neutralize reactive oxygen species and mitigate oxidative stress in the ischemic brain. Combined, the activation of SIRT1 and NRF2 pathways contributes to resveratrol's neuroprotective effects by reducing oxidative stress, inflammation, and apoptosis in IS. Preclinical studies demonstrate that resveratrol improves functional outcomes, reduces infarct size, regulates cerebral blood flow and preserves neuronal integrity. Gaining a comprehensive understanding of these mechanisms holds promise for the development of targeted therapeutic interventions aimed at promoting neuronal survival and facilitating functional recovery in IS patients and to aid future studies in this matter.

Cynaropicrin Averts the Oxidative Stress and Neuroinflammation in Ischemic/Reperfusion Injury Through the Modulation of NF-kB

Cerebral ischemia and successive reperfusion are the prevailing cause of cerebral stroke. Currently cerebral stroke is considered to be one of the prior causes for high mortality, disability, and morbidity. Cynaropicrin, a sesquiterpene lactone, exhibits various pharmacologic properties and also has an anti-inflammatory property associated with the suppression of the key pro-inflammatory NF-κB pathway. The protective effect of cynaropicrin against oxidative stress and neuroinflammation during CIR injury through the modulation of NF-κB pathway was studied in the current investigation. The experimental rats split into 5 groups as sham-operated control group (group 1), middle cerebral artery occlusion (MCAO)-induced rats (group 2), MCAO rats treated with cynaropicrin (diluted in saline) immediately 2 h after MCAO with 5, 10, and 25 mg/kg administration orally were designated as groups 3, 4, and 5, respectively. In MCAO-induced animals, the severity of ischemic was evident by the elevated level nitrate, MDA, MMPs, inflammatory mediators, Bax, caspase-3, and NF-κB. The level of Nrf-2, antioxidant enzymes, Bcl-2, and IL-10 was reduced in the MCAO-induced animals. Treatment with cynaropicrin in dosage-based manner increased the level of antioxidant enzymes, IL-10, Nrf-2, and Bcl-2 in the animals which indicates the antioxidative effect of cynaropicrin. The level of nitrate, MDA, MMPs, proinflammatory cytokines, inflammatory mediators, Bax, caspase-3, and NF-κB was reduced in the rats treated with cynaropicrin in a dosage-based manner. Experimental animals treated with cynaropicrin in a dosage-dependent way showed a defensive mechanism against oxidative stress and neuroinflammation by inhibiting the NF-κB pathway.

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.

Natural Products: A Promising Therapeutics for Targeting Tumor Angiogenesis

Tumor-associated angiogenesis is a key target for anti-cancer therapy. The imbalance between pro-angiogenic and anti-angiogenic signals elicited by tumor cells or tumor microenvironment always results in activating "angiogenic switch". Tumor angiogenesis functions in multi-aspects of tumor biology, including endothelial cell apoptosis, tumor metastasis, and cancer stem cell proliferation. Numerous studies have indicated the important roles of inexpensive and less toxic natural products in targeting tumor angiogenesis-associated cytokines and apoptotic signaling pathways. Our current knowledge of tumor angiogenesis is based mainly on experiments performed on cells and animals, so we summarized the well-established models for angiogenesis both in vitro and in vivo. In this review, we classified and summarized the anti-angiogenic natural agents (Polyphenols, Polysaccharides, Alkaloids, Terpenoids, Saponins) in targeting various tumor types according to their chemical structures at present, and discussed the mechanistic principles of these natural products on regulating angiogenesis-associated cytokines and apoptotic signaling pathways. This review is to help understanding the recent progress of natural product research for drug development on anti-tumor angiogenesis.

Resveratrol (RV): A pharmacological review and call for further research

Resveratrol (RV) is a well-known polyphenolic compound in various plants, including grape, peanut, and berry fruits, which is quite famous for its association with several health benefits such as anti-obesity, cardioprotective neuroprotective, antitumor, antidiabetic, antioxidants, anti-age effects, and glucose metabolism. Significantly, promising therapeutic properties have been reported in various cancer, neurodegeneration, and atherosclerosis and are regulated by several synergistic pathways that control oxidative stress, cell death, and inflammation. Similarly, RV possesses a strong anti-adipogenic effect by inhibiting fat accumulation processes and activating oxidative and lipolytic pathways, exhibiting their cardioprotective effects by inhibiting platelet aggregation. The RV also shows significant antibacterial effects against various food-borne pathogens (Listeria, Campylobacter, Staphylococcus aureus, and E. coli) by inhibiting an electron transport chain (ETC) and F0F1-ATPase, which decreases the production of cellular energy that leads to the spread of pathogens. After collecting and analyzing scientific literature, it may be concluded that RV is well tolerated and favorably affects cardiovascular, neurological, and diabetic disorders. As such, it is possible that RV can be considered the best nutritional additive and a complementary drug, especially a therapeutic candidate. Therefore, this review would increase knowledge about the blend of RV as well as inspire researchers around the world to consider RV as a pharmaceutical drug to combat future health crises against various inhumane diseases. In the future, this article will be aware of discoveries about the potential of this promising natural compound as the best nutraceuticals and therapeutic drugs in medicine.

Therapeutic Applications of Resveratrol in Hepatic Encephalopathy through Its Regulation of the Microbiota, Brain Edema, and Inflammation

Hepatic encephalopathy is a common complication in patients with liver cirrhosis and portosystemic shunting. Patients with hepatic encephalopathy present a variety of clinical features, including neuropsychiatric manifestations, cognitive dysfunction, impaired gut barrier function, hyperammonemia, and chronic neuroinflammation. These pathogeneses have been linked to various factors, including ammonia-induced oxidative stress, neuronal cell death, alterations in the gut microbiome, astrocyte swelling, and blood-brain barrier disruptions. Many researchers have focused on identifying novel therapeutics and prebiotics in the hope of improving the treatment of these conditions. Resveratrol is a natural polyphenic compound and is known to exert several pharmacological effects, including antioxidant, anti-inflammatory, and neuroprotective activities. Recent studies suggest that resveratrol contributes to improving the neuropathogenic effects of liver failure. Here, we review the current evidence describing resveratrol's effects in neuropathogenesis and its impact on the gut-liver axis relating to hepatic encephalopathy. We highlight the hypothesis that resveratrol exerts diverse effects in hepatic encephalopathy and suggest that these effects are likely mediated by changes to the gut microbiota, brain edema, and neuroinflammation.

Multi-target drug with potential applications: violacein in the spotlight

The aim of the current review is to address updated research on a natural pigment called violacein, with emphasis on its production, biological activity and applications. New information about violacein's action mechanisms as antitumor agent and about its synergistic action in drug delivery systems has brought new alternatives for anticancer therapy. Thus, violacein is introduced as reliable drug capable of overcoming at least three cancer hallmarks, namely: proliferative signaling, cell death resistance and metastasis. In addition, antimicrobial effects on several microorganisms affecting humans and other animals turn violacein into an attractive drug to combat resistant pathogens. Emphasis is given to effects of violacein combined with different agents, such as antibiotics, anticancer agents and nanoparticles. Although violacein is well-known for many decades, it remains an attractive compound. Thus, research groups have been making continuous effort to help improving its production in recent years, which can surely enable its pharmaceutical and chemical application as multi-task compound, even in the cosmetics and food industries.

Acetylated Resveratrol and Oxyresveratrol Suppress UVB-Induced MMP-1 Expression in Human Dermal Fibroblasts

Resveratrol (RES) and oxyresveratrol (OXYRES) are considered and utilized as active ingredients of anti-aging skin cosmetics. However, these compounds are susceptible to oxidative discoloration and unpleasant odor in solutions, limiting their use in cosmetics. Accordingly, RES and OXYRES were chemically modified to acetylated derivatives with enhanced stability, and their anti-aging effect on the skin and detailed molecular mechanism of their acetylated derivatives were investigated. Acetylated RES and OXYRES lost their acetyl group and exerted an inhibitory effect on H₂O₂-induced ROS levels in human dermal fibroblast (HDF) cells. In addition, RES, OXYRES, and their acetylated derivatives suppressed UVB-induced matrix metalloproteinase (MMP)-1 expression via inhibition of mitogen-activated protein kinases (MAPKs) and Akt/mTOR signaling pathways. Furthermore, RES, OXYRES, and their acetylated derivatives suppressed type I collagen in TPA-treated HDF cells. Collectively, these results suggest the beneficial effects and underlying molecular mechanisms of RES, OXYRES, and their acetylated derivatives for anti- skin aging applications.

Towards resolving the enigma of the dichotomy of resveratrol: cis- and trans-resveratrol have opposite effects on TyrRS-regulated PARP1 activation

Unlike widely perceived, resveratrol (RSV) decreased the average lifespan and extended only the replicative lifespan in yeast. Similarly, although not widely discussed, RSV is also known to evoke neurite degeneration, kidney toxicity, atherosclerosis, premature senescence, and genotoxicity through yet unknown mechanisms. Nevertheless, in vivo animal models of diseases and human clinical trials demonstrate inconsistent protective and beneficial effects. Therefore, the mechanism of action of RSV that elicits beneficial effects remains an enigma. In a previously published work, we demonstrated structural similarities between RSV and tyrosine amino acid. RSV acts as a tyrosine antagonist and competes with it to bind to human tyrosyl-tRNA synthetase (TyrRS). Interestingly, although both isomers of RSV bind to TyrRS, only the cis-isomer evokes a unique structural change at the active site to promote its interaction with poly-ADP-ribose polymerase 1 (PARP1), a major determinant of cellular NAD+-dependent stress response. However, retention of trans-RSV in the active site of TyrRS mimics its tyrosine-bound conformation that inhibits the auto-poly-ADP-ribos(PAR)ylation of PARP1. Therefore, we proposed that cis-RSV-induced TyrRS-regulated auto-PARylation of PARP1 would contribute, at least in part, to the reported health benefits of RSV through the induction of protective stress response. This observation suggested that trans-RSV would inhibit TyrRS/PARP1-mediated protective stress response and would instead elicit an opposite effect compared to cis-RSV. Interestingly, most recent studies also confirmed the conversion of trans-RSV and its metabolites to cis-RSV in the physiological context. Therefore, the finding that cis-RSV and trans-RSV induce two distinct conformations of TyrRS with opposite effects on the auto-PARylation of PARP1 provides a potential molecular basis for the observed dichotomic effects of RSV under different experimental paradigms. However, the fact that natural RSV exists as a diastereomeric mixture of its cis and trans isomers and cis-RSV is also a physiologically relevant isoform has not yet gained much scientific attention.

An interplay of microglia and matrix metalloproteinase MMP9 under hypoxic stress regulates the opticin expression in retina

Inflammation plays a key role in the pathogenesis of retinal vascular diseases. We have shown earlier an increase in the activity of matrix metalloproteinases in the vitreous and tears of preterm born babies with retinopathy of prematurity (ROP) compared to those with no-ROP leading to a shift in the balance of angiogenic (vascular endothelial growth factor [VEGF], matrix metalloproteinase [MMPs], complement component [C3]) and anti-angiogenic (opticin, thrombospondin) in ROP eyes. We now confirmed that tear MMP levels in premature infants perfectly correlates with disease severity. Next, we demonstrated that a reduced opticin levels in ROP vitreous are regulated by MMPs secreted by activated microglia. Upon exposing the human microglia cell line (CHME3) to hypoxia, an increased expression of inflammatory proteins (MMP9, VEGF) was noticed while opticin reduced significantly (p = 0.005). Further, the reduced opticin’s expression by microglial cells under hypoxia could be rescued by inhibiting the MMP activity using doxycycline and EDTA. The inhibition of MMP activity altered the expression of other key signaling molecules under hypoxia. Our study clearly explains that increased activity of MMPs under hypoxia regulates the expression of opticin as seen in the vitreous humor of ROP and could serve as a potential target for ROP management.

Polyphenols and Brazilian red propolis incorporated into a total-etching adhesive system help in maintaining bonding durability

Objectives

The aim of this study was to evaluate the degree of conversion and bond strength of a commercial dental adhesive modified by the incorporation of quercetin, resveratrol (RES), and Brazilian red propolis (BRP).

Methods

BRP markers were identified using ultra-performance liquid chromatography coupled with a diode array detector, and the antioxidant activity (AAO) of the three substances was analyzed. Single Bond 2 adhesive (3M ESPE) was modified by adding BRP, quercetin, and RES, separately, at 20 μg/mL, 250 μg/mL, and 500 μg/mL, respectively. The degree of conversion (DC) was measured using near-infrared spectroscopy 24 h after photopolymerization. Measurements of the resin-dentin microtensile bond strength (μTBS) were carried out after 1 day and 1 year. Student's t test and ANOVA with Tukey's test were used for data analysis (α = 0.05).

Results

The markers daidzein, liquiritigenin, pinobanksin, isoliquiritigenin, formononetin, pinocembrin, and biochanin A were found in the ethanolic extract of BRP. Quercetin, RES, and BRP showed high AAO. The DC of the tested adhesives remained adequate for this category of material, with a slight increase in the DC of adhesives with quercetin and BRP (P > 0.05). Comparisons between μTBS measurements made at 1 day and 1 year showed that, contrary to the control group, μTBS values for all modified adhesives were maintained after 1 year in distilled water (P > 0.05).

Conclusions

These findings suggest that quercetin, RES, or BRP might be useful in adhesive dentistry to help improve hybrid layer resistance.

Clinical significance

Dentin bonding agents with quercetin, RES, and BRP have potential to increase the longevity of composite restorations.

The Protective Effects of Flavonoids in Cataract Formation through the Activation of Nrf2 and the Inhibition of MMP-9

Cataracts account for over half of global blindness. Cataracts formations occur mainly due to aging and to the direct insults of oxidative stress and inflammation to the eye lens. The nuclear factor-erythroid-2-related factor 2 (Nrf2), a transcriptional factor for cell cytoprotection, is known as the master regulator of redox homeostasis. Nrf2 regulates nearly 600 genes involved in cellular protection against contributing factors of oxidative stress, including aging, disease, and inflammation. Nrf2 was reported to disrupt the oxidative stress that activates Nuclear factor-κB (NFκB) and proinflammatory cytokines. One of these cytokines is matrix metalloproteinase 9 (MMP-9), which participates in the decomposition of lens epithelial cells (LECs) extracellular matrix and has been correlated with cataract development. Thus, during inflammatory processes, MMP production may be attenuated by the Nrf2 pathway or by the Nrf2 inhibition of NFκB pathway activation. Moreover, plant-based polyphenols have garnered attention due to their presumed safety and efficacy, nutritional, and antioxidant effects. Polyphenol compounds can activate Nrf2 and inhibit MMP-9. Therefore, this review focuses on discussing Nrf2's role in oxidative stress and cataract formation, epigenetic effect in Nrf2 activity, and the association between Nrf2 and MMP-9 in cataract development. Moreover, we describe the protective role of flavonoids in cataract formation, targeting Nrf2 activation and MMP-9 synthesis inhibition as potential molecular targets in preventing cataracts.

Therapeutic potential of nutraceuticals to protect brain after stroke

Stroke leads to significant neuronal death and long-term neurological disability due to synergistic pathogenic mechanisms. Stroke induces a change in eating habits and in many cases, leads to undernutrition that aggravates the post-stroke pathology. Proper nutritional regimen remains a major strategy to control the modifiable risk factors for cardiovascular and cerebrovascular diseases including stroke. Studies indicate that nutraceuticals (isolated and concentrated form of high-potency natural bioactive substances present in dietary nutritional components) can act as prophylactic as well as adjuvant therapeutic agents to prevent stroke risk, to promote ischemic tolerance and to reduce post-stroke consequences. Nutraceuticals are also thought to regulate blood pressure, delay neurodegeneration and improve overall vascular health. Nutraceuticals potentially mediate these effects by their powerful antioxidant and anti-inflammatory properties. This review discusses the studies that have highlighted the translational potential of nutraceuticals as stroke therapies.

Resveratrol protects retinal ganglion cell axons through regulation of the SIRT1-JNK pathway

It is reported that Ischemia and reperfusion damage (I/R damage) can lead to retinal ganglion cell (RGC) death and neurodegeneration, which in turn can lead to irreversible vision loss. In this study, we sought to understand the neuroprotective effect of resveratrol, the important activator of sirtuin1 (SIRT1), on RGC survival in I/R damage model and the molecular mechanism that mediate this effect. Our results show that resveratrol could reverse axonal swelling, holes, and the chaos of the nucleus in axons of RGCs caused by I/R. At the same time, resveratrol could also reverse the activation of retinal astrocytes and the loss of RGCs caused by I/R. Resveratrol increased the expression of SIRT1 while decreasing the phosphorylation of N-terminal kinase (JNK). SP600125(JNK inhibitor) decreased the phosphorylation of JNK while increasing the expression of SIRT1, indicating that SIRT1 and JNK can interact with each other. Simultaneous administration of resveratrol and sirtinol (SIRT1 inhibitor) neither increased the expression of SIRT1 nor decreased the phosphorylation of JNK, indicating that resveratrol affects the phosphorylation of JNK by SIRT1. In total, our research shows that resveratrol treatment significantly reduces apoptosis and axonal degeneration of RGCs, and this protection is partly mediated through the SIRT1-JNK pathway.

Resveratrol protects retinal ganglion cells against ischemia induced damage by increasing Opa1 expression

Loss of idiopathic retinal ganglion cells (RGCs) leads to irreversible vision defects and is considered the primary characteristic of glaucoma. However, effective treatment strategies in terms of RGC neuroprotection remain elusive. In the present study, the protective effects of resveratrol on RGC apoptosis, and the mechanisms underlying its effects were investigated, with a particular emphasis on the function of optic atrophy 1 (Opa1). In an ischemia/reperfusion (I/R) injury model, the notable thinning of the retina, significant apoptosis of RGCs, reduction in Opa1 expression and long Opa1 isoform to short Opa1 isoform ratios (L-Opa1/S-Opa1 ratio) were observed, all of which were reversed by resveratrol administration. Serum deprivation resulted in reductions in R28 cell viability, superoxide dismutase (SOD) activity, Opa1 expression and induced apoptosis, which were also partially reversed by resveratrol treatment. To conclude, results from the present study suggest that resveratrol treatment significantly reduced retinal damage and RGC apoptosis in I/R injury and serum deprivation models. In addition, resveratrol reversed the downregulated expression of Opa1 and reduced SOD activity. Mechanistically, resveratrol influenced mitochondrial dynamics by regulating the L-Opa1/S-Opa1 ratio. Therefore, these observations suggest that resveratrol may exhibit potential as a therapeutic agent for RGC damage in the future.

Targeting Myeloperoxidase (MPO) Mediated Oxidative Stress and Inflammation for Reducing Brain Ischemia Injury: Potential Application of Natural Compounds

Oxidative stress and inflammation are two critical pathological processes of cerebral ischemia-reperfusion injury. Myeloperoxidase (MPO) is a critical inflammatory enzyme and therapeutic target triggering both oxidative stress and neuroinflammation in the pathological process of cerebral ischemia-reperfusion injury. MPO is presented in infiltrated neutrophils, activated microglial cells, neurons, and astrocytes in the ischemic brain. Activation of MPO can catalyze the reaction of chloride and H2O2 to produce HOCl. MPO also mediates oxidative stress by promoting the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), modulating the polarization and inflammation-related signaling pathways in microglia and neutrophils. MPO can be a therapeutic target for attenuating oxidative damage and neuroinflammation in ischemic stroke. Targeting MPO with inhibitors or gene deficiency significantly reduced brain infarction and improved neurological outcomes. This article discusses the important roles of MPO in mediating oxidative stress and neuroinflammation during cerebral ischemia-reperfusion injury and reviews the current understanding of the underlying mechanisms. Furthermore, we summarize the active compounds from medicinal herbs with potential as MPO inhibitors for anti-oxidative stress and anti-inflammation to attenuate cerebral ischemia-reperfusion injury, and as adjunct therapeutic agents for extending the window of thrombolytic treatment. We highlight that targeting MPO could be a promising strategy for alleviating ischemic brain injury, which merits further translational study.

Corrigendum: Resveratrol inhibits matrix metalloproteinases to attenuate neuronal damage in cerebral ischemia: a molecular docking study exploring possible neuroprotection

[This corrects the article DOI: 10.4103/1673-5374.155429].

Role of the PGE2 receptor in ischemia-reperfusion injury of the rat retina

Purpose

To investigate the function and expression of the PGE2 receptors EP1-4 in rat retinal ischemia-reperfusion (I/R) injury and to determine the regulatory role of resveratrol (RES) in this process.

Methods

In vitro, we stimulated primary astrocytes extracted from the optic disc of rats with epidermal growth factor (EGF) and RES, and detected the location of EP1-4 expression with immunofluorescence. The expression of antiglial fibrillary acidic protein (GFAP), EGF receptor (EGFR), inducible NOS (iNOS), and EP1-4 in astrocytes was detected with western blotting. In vivo, we established an I/R injury model and RES treatment model with Sprague-Dawley rats. Changes in the thickness of the inner retina were observed with hematoxylin and eosin (H&E) staining. EP1-4 localization in the retina was observed with immunohistochemistry. The expression of COX-2, iNOS, and EP1-4 in the control and model groups was detected with western blotting.

Results

In this study, immunofluorescence and immunohistochemistry showed that EP1-4 are expressed in astrocytes and the rat retina. EGF stimulation increased the expression of EGFR, iNOS, EP1, EP2, and EP4 in astrocytes. The expression of EP1-4 was statistically significantly increased on the third day after model induction, and EP1-4 expression decreased to normal levels on day 7. EGF and RES mediated the decrease in the expression of EP2. RES treatment significantly reduced retinal damage and RGC loss, as demonstrated by the relatively intact tissue structure on day 7 observed with H&E staining. Moreover, inflammation was associated with this I/R injury model, as demonstrated by the early induction of proinflammatory mediators, and this inflammation was significantly attenuated after RES treatment.

Conclusions

These results indicate that the COX-2/PGE2/EPs pathway is involved in retinal damage and astrocyte inflammation. In addition, the results suggest that the neuroprotective effects of RES may be associated with decreased production of inflammatory mediators. These results suggest that the PGE2 receptor may be a key factor in the treatment of neurodegenerative diseases, and that RES may be used as a possible therapeutic strategy for glaucoma.

Nutraceuticals and Hypertensive Disorders in Pregnancy: The Available Clinical Evidence

The aim of the present critical review is to summarize the available clinical evidence supporting the use of some dietary supplements that have been shown to lower blood pressure in hypertensive pregnant women. A systematic search strategy was carried out to identify trials in MEDLINE (National Library of Medicine, Bethesda, Maryland, MD, USA; January 1980 to September 2019) and the Cochrane Register of Controlled Trials (The Cochrane Collaboration, Oxford, UK). The terms 'nutraceuticals', 'dietary supplements', 'pregnancy', 'pre-eclampsia', 'clinical trial', and 'human' were incorporated into an electronic search strategy. The references of the identified studies and review articles were reviewed to look for additional studies of interest. We preferably selected papers that reported recent comprehensive reviews or meta-analysis, or original clinical trials of substances with blood pressure-lowering or vascular protective effect in pregnancy. There is a relative body of evidence that supports the use of calcium, vitamin D, folic acid, and resveratrol in preventing the development of hypertensive disorders in pregnancy, and evidence supporting drug treatment too. Further clinical research is advisable to identify the dosage and timing of the supplementation, the group of women that might benefit the most from this approach, and the nutraceuticals with the best cost-effectiveness and risk-benefit ratio for widespread use in clinical practice.

Neuroprotection mediated by natural products and their chemical derivatives

Neuronal injuries can lead to various diseases such as neurodegenerative diseases, stroke, trauma, ischemia and, more specifically, glaucoma and optic neuritis. The cellular mechanisms that regulate neuronal death include calcium influx and calcium overload, excitatory amino acid release, oxidative stress, inflammation and microglial activation. Much attention has been paid to the effective prevention and treatment of neuroprotective drugs by natural products. This review summarizes the neuroprotective aspects of natural products, extracted from Panax ginseng, Camellia sinensis, soy and some other plants, and some of their chemical derivatives. Their antioxidative and anti-inflammatory action and their inhibition of apoptosis and microglial activation are assessed. This will provide new directions for the development of novel drugs and strategies to treat neurodegenerative diseases.

Resveratrol and the Interaction between Gut Microbiota and Arterial Remodelling

Arterial remodelling refers to the alteration in the structure of blood vessel that contributes to the progression of hypertension and other cardiovascular complications. Arterial remodelling is orchestrated by the crosstalk between the endothelium and vascular smooth muscle cells (VSMC). Vascular inflammation participates in arterial remodelling. Resveratrol is a natural polyphenol that possesses anti-oxidant and anti-inflammatory properties and has beneficial effects in both the endothelium and VSMC. Resveratrol has been studied for the protective effects in arterial remodelling and gut microbiota, respectively. Gut microbiota plays a critical role in the immune system and inflammatory processes. Gut microbiota may also regulate vascular remodelling in cardiovascular complications via affecting endothelium function and VSMC proliferation. Currently, there is new evidence showing that gut microbiota regulate the proliferation of VSMC and the formation of neointimal hyperplasia in response to injury. The change in population of the gut microbiota, as well as their metabolites (e.g., short-chain fatty acids) could critically contribute to VSMC proliferation, cell cycle progression, and migration. Recent studies have provided strong evidence that correlate the effects of resveratrol in arterial remodelling and gut microbiota. This review aims to summarize recent findings on the resveratrol effects on cardiovascular complications focusing on arterial remodelling and discuss the possible interactions of resveratrol and the gut microbiota that modulate arterial remodelling.

Human Skin Lightening Efficacy of Resveratrol and Its Analogs: From in Vitro Studies to Cosmetic Applications

Antioxidants are deemed useful in controlling oxidative stress associated with extrinsic skin aging and pigmentation disorders. Resveratrol is a polyphenol compound found in many edible plants such as Vitis vinifera, and its inhibitory effects on the catalytic activity, gene expression, and posttranslational modifications of tyrosinase, a key enzyme in the melanin biosynthetic pathway, provide a mechanistic basis for its antimelanogenic effects seen in melanocytic cells, three-dimensionally reconstituted skin models, and in vivo animal models. As a potent antioxidant and a modulator of nuclear factor erythroid 2-related factor 2 (Nrf2), and sirtuin 1, resveratrol can also regulate multiple signaling pathways associated with inflammation and premature aging. Recent clinical studies have supported the efficacy of resveratrol and its analogs, such as resveratryl triacetate (RTA) and resveratryl triglycolate (RTG), in human skin lightening and antiaging. These findings suggest that resveratrol and its analogs are potentially useful as skin lightening and antiaging agents in cosmetics.

Sijunzi decoction may decrease apoptosis via stabilization of the extracellular matrix following cerebral ischaemia-reperfusion in rats

Neurons undergo degeneration, apoptosis and death due to ischaemic stroke. The present study investigated the effect of Sijunzi decoction (SJZD), a type of traditional Chinese medicine known as invigorating spleen therapy, on anoikis (a type of apoptosis) in rat brains following cerebral ischaemia-reperfusion. Rats were randomly divided into sham, model, nimodipine and SJZD low/medium/high dose groups. A middle cerebral artery occlusion model was established. Neurobehavioural scores were evaluated after administration for 14 days using a five-grade scale. Blood-brain barrier permeability and apoptotic rate were detected using Evans blue (EB) extravasation and TUNEL staining, respectively. Tissue inhibitor of metalloproteinase 1 (TIMP-1), matrix metalloproteinase 9 (MMP-9) and collagen IV (COL IV) were determined using immunohistochemistry. Neurobehavioural scores decreased remarkably in all SJZD and nimodipine groups compared to the model group (P<0.05). Compared with the sham group, EB extravasation was higher in the model group (P<0.01). The amount of EB extravasation decreased in the SJZD high dose and nimodipine groups compared to the model group (P<0.01), and extravasation in the SJZD high dose group was lower than the SJZD low and medium dose groups (P<0.01). TIMP-1 and MMP-9 expression and apoptotic rate increased, but COL IV decreased significantly in the hippocampus of the model group compared to the sham group (P<0.01). TIMP-1 and COL IV expression increased significantly and MMP-9 and apoptotic rate decreased remarkably in all SJZD and nimodipine groups compared to the model group (P<0.01). TIMP-1 and COL IV expression decreased, but MMP-9 expression and apoptotic rate increased in the SJZD low and medium dose groups compared to the SJZD high dose group (P<0.01). SJZD rescued neurons and improved neurobehavioural function in rats following cerebral ischaemia-reperfusion, especially when used at a high dose. The mechanism may be related to protection of the extracellular matrix followed by anti-apoptotic effects.

Resveratrol Delays Retinal Ganglion Cell Loss and Attenuates Gliosis-Related Inflammation From Ischemia-Reperfusion Injury

Purpose

Resveratrol has been shown to enhance the survival of retinal ganglion cells (RGCs) following ischemia-reperfusion (I/R) injury for glaucoma. However, the precise mechanisms for resveratrol's protective effects are still unclear. The aim of this study is to determine whether resveratrol can inhibit RGC apoptosis, retinal gliosis, and inflammation, all of which are critical events in retinal degeneration following I/R injury.

Methods

Right retinal ischemia was induced in adult male Sprague Dawley rats by increasing intraocular pressure to 110 mm Hg for 60 minutes, and the left eyes maintained at normal pressure serve as the control. Intraperitoneal injection of resveratrol or control buffer was performed continuously for 3 days from pre- to post-I/R injury and the protective effects were evaluated and compared. RGCs were retrogradely labeled with Fluoro-Gold by injection into superior colliculi. Apoptosis was detected by TUNEL staining. Western blotting and immunostaining for Bax, Bcl-2, and Caspase-3 were used to explore the Bax-associated apoptotic pathway. Gliosis was assessed by western blotting and immunostaining of retinal cross sections with anti-glial fibrillary acidic protein (GFAP) antibodies.

Results

In this study, resveratrol treatment significantly reduced retinal damage and RGC loss as demonstrated by the relatively intact tissue structure in hematoxylin and eosin staining at day 7 and increased Fluoro-Gold labeling of RGCs at day 14, respectively. We found that resveratrol exhibited an anti-apoptotic effect as assessed by reduced TUNEL staining, inhibition of the early upregulated expression of the apoptosis-related protein Bax, and decreased subsequently cleaved caspase-3. However, it did not affect Bcl-2 levels. Moreover, in our I/R injury model, the combined response of reactive gliosis and related inflammation, which were demonstrated by an early induction of pro-inflammatory mediators and subsequently increased GFAP level, were significantly attenuated after resveratrol treatment.

Conclusions

These results demonstrate that resveratrol can prevent RGC death by blocking the Bax-caspase-3-dependent apoptotic pathway and suppressed gliosis-related inflammation in the retina after I/R injury. Together these results support the use of resveratrol as a possible therapeutic strategy for glaucoma.

Targets, Treatments, and Outcomes Updates in Diabetic Stroke

GOAL

Due to multiple failures to translate basic research, the need for novel therapeutic targets and strategies is still urgent to save a larger number of the stroke patients' population and to reduce the toxicity of the current stroke therapy.

METHOD

We summarize the most recent, within past 5 years, basic and clinical diabetic stroke research findings.

FINDINGS

We aim to examine the most current understanding of stroke and neurovascular unit integrity, especially in presence of hyperglycemia and/or diabetes mellitus. From there, we are comparing the meaningful findings that aim at treating diabetic stroke to see where they differ, where they succeed, and where they open questions for new therapeutic strategies.

CONCLUSION

The need for more clinically effective neuroprotective strategies is still mismatched with the bench side findings.

Inhibition of Gelatinases (MMP-2 and MMP-9) by Withania somnifera Phytochemicals Confers Neuroprotection in Stroke: An In Silico Analysis

A stroke or cerebrovascular accident is a serious, life-threatening medical condition that occurs when the blood supply to part of the brain is severely reduced or cut off, depriving brain tissue of oxygen and nutrients. Studies suggested that level of gelatinases (MMP-2 and MMP-9) usually increases in the brain after stroke. The elevated activity of gelatinases plays the deleterious role in ischemic stroke, hemorrhagic stroke and perinatal hypoxic-ischemic brain injury. Therefore, matrix metalloproteinase (MMP)-2 and MMP-9 inhibition have therapeutic importance in stroke condition. Present in silico study investigates whether Withania somnifera (WS) phytochemicals inhibit the MMP-2 and MMP-9 by binding to the catalytic domain, as similar to their inhibitor or not. For that, we performed molecular docking study to evaluate the gelatinases-inhibitory potential of 36 WS phytochemicals, which compared with gelatinases inhibitors viz. hydroxamic acid, quercetin, doxycycline, minocycline and reverse hydroxamate. The results suggest that 28 out of 36 WS phytochemicals show higher affinity for MMP-2 owing to bind with active site residues of S1'-pocket with lower binding energy and smaller inhibition constant (Ki) than considered inhibitors. As well as, withanolide G and withafastuosin E show higher affinity for MMP-9 than reverse hydroxamate inhibitor. These phytochemicals have neuroprotective potential as an inherently useful oral drug to combat ischemic and hemorrhagic stroke mediated by gelatinases.

Enzymatic inhibitory activity of iridoid glycosides from Picrorrhiza kurroa against matrix metalloproteinases: Correlating in vitro targeted screening and docking

One specific group of MMPs; gelatinases A (MMP-2) and B (MMP-9) are of precise interest in view of the development and progression of cancer. In the current work, an attempt was made to investigate the enzymatic inhibitory activity of Kutkin (KT), Kutkoside (KS), and Picroside I (PS) by inhibition assay and to further check the downregulation of the expression of mRNA levels of MMP-2 and -9. Further in silico docking studies were performed to investigate the interaction of KT, KS and PS with MMP-2 and MMP-9. The results revealed a dose dependent cytotoxic activity of the compounds under investigation and showed a significant inhibition of MMP-9 in comparison to the activity against MMP-2. In addition, a considerable decrease in expression of mRNA levels (MMP-9) was observed in KT, KS, and PS-treated MDA-MB-231 and MDA-MB-435 cancer cells as was detected by reverse transcriptase polymerase chain reaction (semi-quantitative RT-PCR). The molecular docking studies between KT, KS, PS with MMPs revealed that KT, KS, PS occupied the active site of MMP-9 and showed better binding interactions in comparison to MMP-2. The binding energies of the complexes were -7.4, -7.1 and -7.2 kJ/mol for KT, KS and PS with MMP-9, respectively and -8.9, -8.0 and -8.0 kJ/mol for KT, KS and PS with MMP-2, respectively. The findings from the in vitro studies revealed that KT, KS and PS exhibited significant anti-proliferative effects on both MDA-MB-231 and MDA-MB-435 breast cancer cells. In addition, the results of inhibition assay showed that MMP-9 activity was significantly inhibited by KT, KS and PS and the results were consistent with in silico assay.

Vesicular systems employing natural substances as promising drug candidates for MMP inhibition in glioblastoma: A nanotechnological approach

Glioblastoma multiforme (GBM), one of the most lethal Brain tumors, characterized by its high invasive nature and increased mortality rates forms a major bottleneck in transport of therapeutics across the Blood Brain Barrier (BBB). Matrix metalloproteinases (MMPs) are classified as enzymes, which are found to be up regulated in the Glioma tumor microenvironment and thus can be considered as a target for inhibition for curbing GBM. Many chemotherapeutics and techniques have been employed for inhibiting MMPs till now but all of them failed miserably and were withdrawn in clinical trials due to their inability in restricting the tumor growth or increasing the overall survival rates. Thus, the quest for finding the suitable MMP inhibitor is still on and there is a critical need for identification of novel compounds which can alter the BBB permeability, restrain tumor growth and prevent tumor recurrence. Currently, naturally derived substances are gaining widespread attention as tumor inhibitors and many studies have been reported by far highlighting their importance in restricting MMP expression thus serving as chemotherapeutics for cancer due to their minimal toxicity. These substances may serve as probable candidates for inhibiting MMP expression in GBM. However, targeting and delivering the inhibitor to its target site is an issue that needs to be overcome in order to attain maximum specificity and sustained release. The birth of nanotechnology served as a boon in delivering drugs to the most complicated areas thus paving way for Nano drug delivery. An efficient Nano carrier with ability to cross the BBB and competently kill the Glioma cells forms the prerequisite for GBM chemotherapy. Vesicular drug delivery systems are one such class of carriers, which have the capacity to release the drug at a predetermined rate at the target site thus minimizing any undesirable side effects. Exploiting vesicular systems as promising Nano drug carriers to formulate naturally derived substances, that can bypass the BBB and act as an inhibitor against MMPs in GBM is the main theme of this review.

Resveratrol-Linoleate protects from exacerbated endothelial permeability via a drastic inhibition of the MMP-9 activity

Gelatinolytic matrix metalloproteinases (MMP-2, -9) play a critical role not only in mammals physiology but also during inflammation and healing processes. The natural stilbenoid, resveratrol (RES), exhibits potent antioxidant effects, in a hormetic mode of action, and is known to inhibit MMP-9. However, RES administration exhibits major issues, including poor bioavailability and water solubility, hampering its potential therapeutic effect in vivo. In the present study, we synthesized and evaluated five novel RES–lipid conjugates to increase their cell membrane penetration and improve their bioavailability. The best in vitro MMP-9 inhibitory activity of RES–lipids conjugates was observed with RES-linoleic acid (LA) (5 µM), when dissolved in a natural deep eutectic solvent (NADES), composed of an equimolar content of 1,2-propanediol:choline chloride (ChCl):water. The inhibition of MMP-9 expression by RES-LA in activated THP-1 monocytes, was, at least due to the deactivation of ERK1/2 and JNK1/2 MAP kinase signaling pathways. Moreover, RES-LA exhibited a strong effect protecting the TNF-α-induced exacerbated permeability in an HUVEC in vitro monolayer (by 81%) via the integrity protection of intercellular junction proteins from the MMP-9 activity. This effect was confirmed by using several complementary approaches including, the real-time monitoring of trans-endothelial electric resistance (TEER), the Transwell HUVEC permeability level, the microscopic examination of the platelet endothelial cell adhesion molecule-1 (CD31/PECAM-1) integrity as well as the fluorescence in intercellular spaces. Consequently, following this strong in vitro proof-of-concept, there is a need to test this promising RES–lipid derivative compound to control the pathological endothelial permeability in vivo.

Antiangiogenic cytokines as potential new therapeutic targets for resveratrol in diabetic retinopathy

Diabetes mellitus (DM) affects >350 million people worldwide. With many complications that can reduce the patient’s quality of life, vision loss is one of the most debilitating disorders it can cause. Active research in the field of diabetes includes microvascular complications in diabetic retinopathy (DR). Disturbances in the balance of pro-angiogenesis and anti-angiogenesis factors can lead to the progression of DR. The retinal pigment epithelium (RPE) is the outermost layer of the retina, and it is essential in maintaining the visual function. The RPE produces and secretes growth factors as well as protective agents which maintain structural integrity of the retina. Small natural molecules, such as resveratrol, may influence neurotrophic factors of the retina. The pigment epithelium-derived factor (PEDF) and thrombospondin-1 (TSP-1) are secreted by RPE cells. These two proteins inhibit angiogenesis and inflammation in RPE cells. An alteration of their production contributes to various eye diseases. There is a critical balance between two important factors secreted on opposite sides of the RPE: at the basal side, vascular endothelial growth factor (VEGF; acts on the choroidal endothelium) and, on the apical side, PEDF (acts on neurons and photoreceptors). Resveratrol inhibits VEGF expression in human adult RPE cells and limits the development of proliferative vitreoretinopathy, by attenuating transforming growth factor-β2-induced wound closure and cell migration. Possible new mechanisms could include PEDF and TSP-1 expression alterations under physiological and pathological conditions. Resveratrol is currently of interest due to its capacity to influence the cell’s secretory activity. Some limitations arise from its low bioavailability. Several drug delivery systems are currently tested, promising to improve tissue concentrations. This article reviews biological pathways involved in the pathogenesis of DR that could be influenced by resveratrol. A study of these pathways could identify new potential targets for the reduction of diabetic complications.

Targeting matrix metalloproteinases with novel diazepine substituted cinnamic acid derivatives: design, synthesis, in vitro and in silico studies

Lung cancer is the notable cause of cancer associated deaths worldwide. Recent studies revealed that the expression of matrix metalloproteinases (MMPs) is extremely high in lung tumors compared with non-malignant lung tissue. MMPs (-2 and -9) play an important part in tumor development and angiogenesis, which suggests that creating potent MMP-2 and -9 inhibitors, should be an important goal in lung cancer therapy. In the present study, an effort has been made to develop new anti-metastatic and anti-invasive agents, wherein a series of novel diazepine substituted cinnamic acid derivatives were designed, synthesized and assayed for their inhibitory activities on MMP-2 and MMP-9. These derivatives were prepared via microwave assisted reaction of tert-butyl (3-cinnamamidopropyl)carbamate derivatives mixed with 2,3-dibromopropanoic acid and potassium carbonate was added to obtain 4-(tert-butoxycarbonyl)-1-cinnamoyl-1,4-diazepane-2-carboxylic acid derivatives. The newly synthesized compounds were characterized by IR, NMR and mass spectroscopy. All the tested compounds showed good to excellent cytotoxic potential against A549 human lung cancer cells. The active compounds displaying good activity were further examined for the inhibitory activity against MMPs (-2 and -9). In addition, the structure and anticancer activity relationship were further supported by in silico docking studies of the active compounds against MMP-2 and MMP-9.

Hypothermia and brain inflammation after cardiac arrest

The cessation (ischemia) and restoration (reperfusion) of cerebral blood flow after cardiac arrest (CA) induce inflammatory processes that can result in additional brain injury. Therapeutic hypothermia (TH) has been proven as a brain protective strategy after CA. In this article, the underlying pathophysiology of ischemia-reperfusion brain injury with emphasis on the role of inflammatory mechanisms is reviewed. Potential targets for immunomodulatory treatments and relevant effects of TH are also discussed. Further studies are needed to delineate the complex pathophysiology and interactions among different components of immune response after CA and identify appropriate targets for clinical investigations.

Efficacy of resveratrol to supplement oral nifedipine treatment in pregnancy-induced preeclampsia

OBJECTIVE

Preeclampsia (PE) is a complication affecting pregnant women worldwide, which usually manifests as severe maternal hypertension. Resveratrol (RESV), a naturally existing polyphenol, is known to exhibit beneficial effects in cardiovascular disease including hypertension. We evaluated the outcome of treatment combining oral nifedipine (NIFE) and RESV against PE.

DESIGN AND METHODS

Using a randomized group assignment, 400 PE patients were enrolled and received oral treatments of either NIFE + RESV or NIFE + placebo. Primary endpoints were defined as time to control blood pressure and time before a new hypertensive crisis. Secondary endpoints were defined as the number of doses needed to control blood pressure, maternal and neonatal adverse effects.

RESULTS

Compared with the NIFE + placebo group, the time needed to control blood pressure was significantly reduced in NIFE + RESV group, while time before a new hypertensive crisis was greatly delayed in NIFE + RESV group. The number of treatment doses needed to control blood pressure was also categorically lower in NIFE + RESV group. No differences in maternal or neonatal adverse effects were observed between the two treatment groups.

CONCLUSION

Our data support the potential of RESV as a safe and effective adjuvant of oral NIFE to attenuate hypertensive symptoms among PE patients.

New insights into the antiangiogenic and proangiogenic properties of dietary polyphenols

Polyphenols can be found in natural products of plant origin, including vegetables, fruits, and beverages. A large number of these plant origin compounds are an integral part of the human diet and in the past decade evidence has shown their beneficial properties in human health, by acting in several cell signaling pathways. Among other beneficial effects, polyphenols have been associated with angiogenesis. Increasing evidence highlighting the ability of dietary polyphenols to influence angiogenesis by interfering with multiple signaling pathways is debated. Particular emphasis is given to the mechanisms that ultimately may induce the formation of capillary-like structures (by increasing endothelial cell proliferation, migration, and invasion) or, conversely, may inhibit the steps of angiogenesis leading to the inhibition/regress of vascular development. Dietary polyphenols can, therefore, be viewed as promising nutraceuticals but important aspects have still to be further investigated, to deep knowledge concerning their concentration-mediated effects, effect of specific polyphenols, and respective metabolites, to ensure their appropriate and effective usefulness as proangiogenic or antiangiogenic nutraceuticals.

Neuroprotection and antioxidants

Ischemia as a serious neurodegenerative disorder causes together with reperfusion injury many changes in nervous tissue. Most of the neuronal damage is caused by complex of biochemical reactions and substantial processes, such as protein agregation, reactions of free radicals, insufficient blood supply, glutamate excitotoxicity, and oxidative stress. The result of these processes can be apoptotic or necrotic cell death and it can lead to an irreversible damage. Therefore, neuroprotection and prevention of the neurodegeneration are highly important topics to study. There are several approaches to prevent the ischemic damage. Use of many modern therapeutical methods and the incorporation of several substances into the diet of patients is possible to stimulate the endogenous protective mechanisms and improve the life quality.

The neuroprotective mechanism of ampicillin in a mouse model of transient forebrain ischemia

Ampicillin, a β-lactam antibiotic, dose-dependently protects neurons against ischemic brain injury. The present study was performed to investigate the neuroprotective mechanism of ampicillin in a mouse model of transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral common carotid artery occlusion for 40 min. Before transient forebrain ischemia, ampicillin (200 mg/kg, intraperitoneally [i.p.]) or penicillin G (6,000 U/kg or 20,000 U/kg, i.p.) was administered daily for 5 days. The pretreatment with ampicillin but not with penicillin G signifi cantly attenuated neuronal damage in the hippocampal CA1 subfield. Mechanistically, the increased activity of matrix metalloproteinases (MMPs) following forebrain ischemia was also attenuated by ampicillin treatment. In addition, the ampicillin treatment reversed increased immunoreactivities to glial fibrillary acidic protein and isolectin B4, markers of astrocytes and microglia, respectively. Furthermore, the ampicillin treatment significantly increased the level of glutamate transporter-1, and dihydrokainic acid (DHK, 10 mg/kg, i.p.), an inhibitor of glutamate transporter-1 (GLT-1), reversed the neuroprotective effect of ampicillin. Taken together, these data indicate that ampicillin provides neuroprotection against ischemia-reperfusion brain injury, possibly through inducing the GLT-1 protein and inhibiting the activity of MMP in the mouse hippocampus.