Resveratrol prevents oxidative stress and inhibition of Na(+)K(+)-ATPase activity induced by transient global cerebral ischemia in rats

High-throughput transcriptome sequencing reveals the protective role of adenosine receptor-related genes in paraquat-exposed Caenorhabditis elegans

This study sought to identify the genes associated with adenosine's protective action against paraquat (PQ)-induced oxidative stress via the adenosine receptor (ADOR-1) in Caenorhabditis elegans (C. elegans). The C. elegans was divided into 3 groups-2 groups exposed to PQ, one in presence, and one in absence of adenosine-and a control group that was not treated. Each group's total RNA was extracted and sequenced. When the transcriptomes of these groups were analyzed, several genes were found to be differently expressed. These differentially expressed genes were significantly enriched in adenosine-response biological processes and pathways, including gene ontology terms related to neuropeptide and kyoto encyclopedia of genes and genomes pathways associated to cAMP pathway regulator activity. Quantitative reverse-transcription PCR confirmed that G-protein-coupled receptors signaling pathway involving dop-1, egl-30, unc-13, kin-1, and goa-1 genes may play crucial roles in modulating adenosine's protective action. Interestingly, there are no significant variations in the expression of the ador-1 gene across the 3 treatments, thereby indicating that adenosine receptor exerts a consistent and stable influence on its related pathways irrespective of the presence or absence of PQ. Furthermore, the wild-type group with ador-1 gene has higher survival rate than that of the ador-1-/RNA interference group while treated with PQ in the presence of adenosine. Conclusively, our study uncovered a number of novel PQ-response genes and adenosine receptor-related genes in C. elegans, which may function as major regulators of PQ-induced oxidative stress and indicate the possible protective effects of adenosine.

Intestinal mucosal flora of the intestine-kidney remediation process of diarrhea with deficiency kidney-yang syndrome in Sishen Pill treatment: Association with interactions between Lactobacillus johnsonii, Ca2+-Mg2+-ATP-ase, and Na+-K+-ATP-ase

This study aims to investigate the effect of Sishen Pill on the characteristics of gut mucosal microbiota in diarrhea mice with deficiency kidney-yang syndrome. Fifteen Kunming male mice were randomly divided into Normal control group (C), Model self-healing group (X) and Sishen Pill group (S), with 5 mice/cages. Hematoxylin eosin (HE) staining was used to observe the kidney structure. Serum Na⁺-K⁺-ATP-ase and Ca²⁺-Mg²⁺-ATP-ase were detected by enzyme-linked immunosorbent assay (ELISA), Analysis of intestinal mucosal flora using third-generation high-throughput sequencing. The relative abundance results in the three groups revealed that the dominant bacterial genera: Lactobacillus, Muribaculum and Candidatus-Arthromitus; bacterial species: Lactobacillus johnsonii, Lactobacillus reuteri, Lactobacillus murinus, and Lactobacillus intestinalis, and differences in the presence of major microbiota between the X and S groups. A positive correlation between Lactobacillus johnsonii and both Ca²⁺-Mg²⁺-ATP-ase and Na⁺-K⁺-ATP-ase was found via correlation analysis. Sishen Pill also changed the manufacture of other secondary metabolites, as well as the metabolism of carbohydrates, glycans, energy, lipids, and other amino acids, and xenobiotics biodegradation and metabolism. In conclusion, Sishen Pill improved kidney structure, energy metabolism and the diversity and structure of intestinal mucosal flora. In addition, Lactobacillus johnsonii may be a characteristic species of Sishen Pill in treating diarrhea with kidney-yang deficiency syndrome.

Diarrhea with deficiency kidney-yang syndrome caused by adenine combined with Folium senna was associated with gut mucosal microbiota

The present study aims to study and analyze the characteristics of gut mucosal microbiota in diarrhea mice with deficiency kidney-yang syndrome. Ten male mice were randomly divided into the control group and the model group. Diarrhea mice model with deficiency kidney-yang syndrome was established by adenine combined with Folium sennae. The kidney structure was observed by hematoxylin-eosin (HE) staining. Serum Na+-K+-ATP-ase and Ca2+-Mg2+-ATP-ase were detected by enzyme-linked immunosorbent assay (ELISA). The characteristics of gut mucosal microbiota were analyzed by performing third-generation high-throughput sequencing. The results showed that the model mice exhibit obvious structural damage to the kidney. Serum Na+-K+-ATP-ase and Ca2+-Mg2+-ATP-ase levels showed a decreased trend in the model group. The diversity and community structure of the gut mucosal microbiota improved in the model group. Dominant bacteria like Candidatus Arthromitus, Muribaculum, and Lactobacillus reuteri varied significantly at different taxonomic levels. The characteristic bacteria like Bacteroides, Erysipelatoclostridium, Anaerotignum, Akkermansia muciniphila, Clostridium cocleatum, Bacteroides vulgatus, and Bacteroides sartorii were enriched in the model group. A correlation analysis described that Erysipelatoclostridium was positively correlated with Na+-K+-ATP-ase and Ca2+-Mg2+-ATP-ase levels, while Anaerotignum exhibited an opposite trend. Together, adenine combined with Folium sennae damaged the structure of the kidney, affected energy metabolism, and caused disorders of gut mucosal microbiota in mice. Bacteroides, Erysipelatoclostridium, and Anaerotignum showed significant inhibition or promotion effects on energy metabolism. Besides, Akkermansia muciniphila, Clostridium cocleatum, Bacteroides vulgatus, and Bacteroides sartorii might be the characteristic species of gut mucosal microbiota responsible for causing diarrhea with deficiency kidney-yang syndrome.

A meta-analysis of resveratrol protects against cerebral ischemia/reperfusion injury: Evidence from rats studies and insight into molecular mechanisms

Objective: To evaluate the neuroprotective effect of resveratrol (RES) in rat models of cerebral ischemia/reperfusion (I/R) injury.

Data sources: PubMed, Embase, MEDLINE, Cochrane Library, and Chinese databases were searched from their inception dates to July 2022. No language restriction was used in the literature search.

Date Selection: Studies were selected that RES were used to treat cerebral I/R injury in vivo. Two reviewers conducted literature screening, data extraction and methodological quality assessment independently.

Outcome measures: Cerebral infarct volume was included as primary outcome. The secondary outcomes included cerebral water content and neurological deficit scores. Malondialdehyde (MDA) and superoxide dismutase (SOD) were used to evaluate oxidative stress during medication.

Results: A total of 41 studies were included, and only a few of them the methodological quality was relatively low. Compared with the control group, RES significantly reduced the cerebral infarct volume (29 studies, standard mean difference (SMD) = −2.88 [−3.23 to −2.53], p < 0.00001) and brain water content (nine studies, MD = −9.49 [−13.58 to −5.40], p < 0.00001) after cerebral I/R injury, then neurological function was improved (15 studies, SMD = −1.96 [−2.26 to −1.65], p < 0.00001). The MDA level (six studies, SMD = −8.97 [−13.60 to −4.34], p = 0.0001) was decreased notably after treatment of RES, while the SOD level (five studies, SMD = 3.13 [−0.16 to 6.43], p = 0.06) was increased unsatisfactory. Consistently, subgroup analysis of cerebral infarct volume suggested that the optimal therapeutic dose is 30 mg/kg (eight studies, SMD = −5.83 [−7.63 to −4.04], p < 0.00001). Meanwhile, 60 min of occlusion (three studies, SMD = −10.89 [−16.35 to −5.42], p < 0.0001) could get maximum benefit from compared with 90 min and 120 min of occlusion. On the other hand, the publication bias cannot be ignored. The pharmacological mechanisms of RES on cerebral I/R injury models as reported have be summarized, which can be used for reference by researchers to further plan their future experiments.

Conclusion: RES might have a good neuroprotective effect on cerebral I/R injury in rats, then 30 mg/kg RES may be the optimal dose for treatment, and early administration of RES should be more neuroprotective. Also it need to be further verified through exploration of dose effect relationship, or delay administration or not.

Limited Role of Rhamnolipids on Cadmium Resistance for an Endogenous-Secretion Bacterium

Rhamnolipids, a type of biosurfactant, represent a potential strategy for both enhancing organismic resistance and in situ remediation of heavy metals contaminations. In-depth study of the mechanism of rhamnolipids synthesis in response to heavy metals stress, is indispensable for a wide use of biosurfactant-secreting microbes in bioremediation. In this study, we employed the wild-type and the rhlAB deficient strain (ΔrhlAB) of Pseudomonas aeruginosa, a prototypal rhamnolipids-producing soil microorganism, to investigate its responses to cadmium resistance based on its physicochemical, and physiological properties. Compared with the wild-type strain, the ΔrhlAB were more sensitive to Cd-stress at low Cd concentration (<50 mg/L), whereas there was little difference in sensitivity at higher Cd concentrations, as shown by spot titers and cell viability assays. Secreted rhamnolipids reduced intracellular Cd²⁺ accumulation to alleviate Cd²⁺ stress, whereas endogenous rhamnolipids played a limited role in alleviating Cd²⁺ stress. Synthesized rhamnolipids exhibited a higher critical micelle concentration (CMC) (674.1 mg/L) and lower emulsification index (4.7%) under high Cd-stress, while these parameters showed no obvious changes. High Cd-stress resulted in high hydrophilic wild-type bacterial surface and lower bioremediation ability. This study could advance a deeper understanding of the mechanism of cadmium resistance and provide a theoretical foundation for the application of biosurfactant and biosurfactant-secreted bacterium in contaminant bioremediation.

Neuroprotection by Trans-Resveratrol in Rats With Intracerebral Hemorrhage: Insights into the Role of Adenosine A1 Receptors

Given the neuroprotective effects of trans-resveratrol (RV), this study aimed to investigate the involvement of the adenosine A1 receptor (A1R) in RV-mediated neuroprotection in a rat intracerebral hemorrhage (ICH) model induced by intrastriatal injection of collagenase. Rats were divided into 5 groups: (1) control, (2) sham-operated, (3) ICH pretreated with vehicle, (4) ICH pretreated with RV, and (5) ICH pretreated with RV and the A1R antagonist DPCPX. At 48 hours after ICH, the rats were subjected to neurological testing. Brain tissues were assessed for neuronal density and morphological features using routine and immunohistochemical staining. Expression of tumor necrosis factor-α (TNF-α), caspase-3, and RIPK3 proteins was examined using ELISA. A1R, MAPK P38, Hsp90, TrkB, and BDNF genes were examined using RT-qPCR. RV protected against neurological deficits and neuronal depletion, restored the expression of TNF-α, CASP3, RIPK3, A1R, and Hsp90, and increased BDNF/TrkB. DPCPX abolished the effects of RV on neurological outcomes, neuronal density, CASP3, RIPK3, A1R, Hsp90, and BDNF. These data indicate that the neuroprotection by RV involves A1R and inhibits CASP3-dependent apoptosis and RIPK3-dependent necroptosis in the perihematoma region; this is likely to be mediated by crosstalk between A1R and the BDNF/TrkB pathway.

Lipid peroxidation reduction and hippocampal and cortical neurons protection against ischemic damage in animal model using Stellaria media

This study was aimed to determine the neuroprotective influence of Stellaria media in terms of restoring normal state of the rat’s hippocampus and cortex after oxidative insult caused by in vitro ischemia and reperfusion. Cell viability and membrane integrity were assessed using MTT and lactate dehydrogenase (LDH) assay, respectively. Ischemic insult was introduced in the rat brain’s hippocampal and cortical slivers by exposing oxygen and glucose deficiency (OGD) for 2 h, followed by 1 h of re-perfusion. Cellular oxidative stress levels were quantified by incorporating 2ʹ,7ʹ-dichlorofluorescein diacetate fluorescent probes. Additionally, the lipid peroxidation was assessed using TBARS assay. Findings revealed significant neuroprotection against OGD-induced mitochondrial impairment at 40 µg/mL of S. media in rat’s hippocampal and cortical slices. The LDH levels were decreased significantly (P < 0.001) during pre-incubation and reoxygenation periods using varied concentrations of S. media extract. Cellular oxidative stress levels results showed significant (P < 0.001) reduction in dichlorofluorescein fluorescence in slices homogenate of hippocampus and cortex using S. media extract. The lipid peroxidation assay results showed decreased (P < 0.01) levels of malondialdehyde in liver tissues of treated rats treated (200 mg/kg body weight) when compared to the ischemic animal. In summary, findings clearly indicated the neuroprotective effects of extract against in vitro ischemia in brain hippocampal and cortex slivers. S. media could undoubtedly be utilized as a healing agent in preventing neuronal cells’ loss during is chemic-reperfusion process.

Neuroprotective effect of green and roasted coffee bean extracts on cerebral ischemia-induced injury in rats

Stroke is a lethal event with a high incidence in Egypt. Quick early intervention can be lifesaving. Transient global ischemia (TGI), a type of ischemic stroke, is mainly instigated by cardiac arrest. Ischemia followed by reperfusion causes further neuronal cell damage. In this study, we aimed to evaluate the potential apoptotic, anti-inflammatory, and neuroprotective effects of green (GCBE) and roasted (RCBE) coffee bean water extract against transient global ischemia-induced via a bilateral common carotid artery occlusion (CAO) in rats. Before CAO, 1.5 ml/kg body weight/day of GCBE or RCBE was administered for 14 days by oral gavage. Ischemia/reperfusion (I/R) and sham groups were treated with a vehicle. Oxidative stress biomarkers and antioxidant enzyme activities, such as MDA, NO, GSH, SOD, CAT, GR, GPx, inflammatory markers TNF-α, IL-1β, and NF-κB, and BDNF were investigated. Quantitative real-time PCR analysis of mitogen-activated protein kinase pathways, in addition to heme oxygenase 1, and nuclear factor erythroid 2-related factor 2 were determined. Apoptotic markers, including Bcl-2, Bax, and caspase 3, in addition to the vascular endothelial growth factor-a, were investigated, followed by an examination of hippocampal histopathology. Pre-administration of GCBE and RCBE improved neurological function and neuronal survival, suppressed the spread of oxidative stress, inflammation, and apoptosis, and reversed most of the pathological changes. However, green coffee bean extract was more effective than roasted coffee bean extract, perhaps due to the roasting process, which may affect active compounds. In conclusion, GCBE and RCBE represent a potential clinical strategy for pre-ischemic conditioning.

Attenuation of doxorubicin-induced cardiotoxicity in Wistar rats by aqueous leaf-extracts of Chromolaena odorata and Tridax procumbens

ETHNOPHARMACOLOGICAL RELEVANCE

Chromolaena odorata (L) King and Robinson and Tridax procumbens Linn are used in traditional medicine in the treatment of diabetes mellitus and hypertension.

AIM OF THE STUDY

This study investigated the potential protective role of aqueous leaf-extracts of Chromolaena odorata and Tridax procumbens against cardiotoxicity induced by doxorubicin.

MATERIALS AND METHODS

To this end, their impact on plasma markers of cardiac integrity, cardiac markers of oxidative stress, cardiac lipids and electrolyte profiles, and activities of cardiac ATPases, lactate dehydrogenase and creatine kinase, were monitored in doxorubicin treated rats. Metformin (250 mg/kg body weight, orally) and both extracts (50, 75 and 100 mg/kg, orally) were daily administered for 14 days; while cardiotoxicity was induced with doxorubicin (15 mg/kg, intra-peritioneally, once on the 12th day of study).

RESULTS

The plasma activities of creatine kinase, lactate dehydrogenase and AST of Test control were significantly (p < 0.05) higher than those of the other groups. Also, the cardiac malondialdehyde, calcium, chloride, sodium, cholesterol and triglyceride concentrations of Test control were significantly (p < 0.05) higher than those of the others. However, the cardiac concentrations of ascorbic acid, reduced glutathione, magnesium and potassium, and cardiac activities of catalase, glutathione peroxidase, superoxide dismutase, Ca2+-ATPase, Mg2+-ATPase, Na+,K+-ATPase, creatine kinase and lactate dehydrogenase of Test control were significantly (p < 0.05) lower than those of the others.

CONCLUSIONS

Pre-treatment with the extracts and metformin elicited a cardioprotective effect, as indicated by the prevention of doxorubicin-induced cardiac oxidative stress and prevention of adverse alterations in plasma cardiac markers, cardiac lipids and electrolyte profiles, as well as improvement of the activities of cardiac ATPases, creatine kinase and lactate dehydrogenase.

Neuroprotective Effect of Maternal Resveratrol Supplementation in a Rat Model of Neonatal Hypoxia-Ischemia

Neonatal hypoxia-ischemia (nHI) is a major cause of death or subsequent disabilities in infants. Hypoxia-ischemia causes brain lesions, which are induced by a strong reduction in oxygen and nutrient supply. Hypothermia is the only validated beneficial intervention, but not all newborns respond to it and today no pharmacological treatment exists. Among possible therapeutic agents to test, trans-resveratrol is an interesting candidate as it has been reported to exhibit neuroprotective effects in some neurodegenerative diseases. This experimental study aimed to investigate a possible neuroprotection by resveratrol in rat nHI, when administered to the pregnant rat female, at a nutritional dose. Several groups of pregnant female rats were studied in which resveratrol was added to drinking water either during the last week of pregnancy, the first week of lactation, or both. Then, 7-day old pups underwent a hypoxic-ischemic event. Pups were followed longitudinally, using both MRI and behavioral testing. Finally, a last group was studied in which breastfeeding females were supplemented 1 week with resveratrol just after the hypoxic-ischemic event of the pups (to test the curative rather than the preventive effect). To decipher the molecular mechanisms of this neuroprotection, RT-qPCR and Western blots were also performed on pup brain samples. Data clearly indicated that when pregnant and/or breastfeeding females were supplemented with resveratrol, hypoxic-ischemic offspring brain lesions were significantly reduced. Moreover, maternal resveratrol supplementation allowed to reverse sensorimotor and cognitive deficits caused by the insult. The best recoveries were observed when resveratrol was administered during both gestation and lactation (2 weeks before the hypoxic-ischemic event in pups). Furthermore, neuroprotection was also observed in the curative group, but only at the latest stages examined. Our hypothesis is that resveratrol, in addition to the well-known neuroprotective benefits via the sirtuin’s pathway (antioxidant properties, inhibition of apoptosis), has an impact on brain metabolism, and more specifically on the astrocyte-neuron lactate shuttle (ANLS) as suggested by RT-qPCR and Western blot data, that contributes to the neuroprotective effects.

Moderation of doxorubicin-induced nephrotoxicity in Wistar rats by aqueous leaf-extracts of Chromolaena odorata and Tridax procumbens

BACKGROUND

The major draw-back of doxorubicin's use in chemotherapy is its toxicity on various organs including the kidneys. This study investigated the potential protective role of aqueous leaf-extracts of Chromolaena odorata and Tridax procumbens against nephrotoxicity induced by doxorubicin.

METHODS

To this end, their impact on plasma biomarkers of kidney function, as well as renal lipid profile, biomarkers of oxidative stress, electrolyte profile and activities of renal ATPases was monitored in doxorubicin treated rats. Metformin (250 mg/kg body weight, orally) and the extracts (50, 75 and 100 mg/kg, orally) were daily administered for 14 days; while nephrotoxicity was induced with doxorubicin (15 mg/kg, intra-peritioneally), once on the 12th day of study.

RESULTS

The plasma concentrations of creatinine, and urea; as well as the renal malondialdehyde, cholesterol, calcium and sodium concentrations in the Test control, were significantly (P < .05) higher than those of all the other groups. However, the renal concentrations of ascorbic acid, chloride, magnesium and potassium, and the renal activities of catalase, glutathione peroxidase superoxide dismutase, Ca2+-ATPase, Mg2+-ATPase and Na+,K+-ATPase in the Test control were significantly (P < .05) lower than those of all the other groups.

CONCLUSIONS

Pre-treatment with the extracts and metformin boosted endogenous antioxidants, and prevented doxorubicin-induced renal damage, as indicated by the attenuation of doxorubicin-induced renal oxidative stress, as well as the attenuation of doxorubicin-induced adverse alterations in renal cholesterol, ATPases and electrolyte balance, and plasma biomarkers of kidney function, and keeping them at near-normal values.

One-Time Acute Heat Treatment Is Effective for Attenuation of the Exaggerated Exercise Pressor Reflex in Rats With Femoral Artery Occlusion

The purpose of this study was to determine the effects of one-time acute heat treatment (HT) on the exaggerated exercise pressor reflex in a model of peripheral arterial insufficiency induced by ligation of the femoral artery and was to further examine the underlying mechanism of ATP-P2X₃ signal activity during this process. The blood pressure (BP) response to static muscle contraction and muscle tendon stretch was recorded to determine the exercise pressor reflex. Also, αβ-methylene ATP (αβ-me ATP) was injected into the arterial blood supply of the hindlimb muscles to stimulate P2X₃ receptors in the muscle afferent nerves. To process one-time acute HT, a heating pad was placed locally on the hindlimb and the muscle temperature (Tm) was increased by ~1.5°C and maintained for 5 min. Compared with control rats, a greater mean arterial pressure (MAP) response to muscle contraction was observed in rats with femoral occlusion in a pre-heat control session (28 ± 2 mmHg in occluded rats/n = 12 vs. 18 ± 2 mmHg in control rats/n = 9; p < 0.05). The one-time acute HT attenuated the amplification of the BP response in rats with femoral artery occlusion (MAP response: 19 ± 8 mmHg in occluded rats + HT/n = 11; p < 0.05 vs. occluded rats). In contrast, HT did not significantly attenuate amplification of MAP response to muscle stretch and αβ-me ATP injection in rats with femoral artery occlusion and controls (all p > 0.05). Our data suggest that one-time acute HT selectively attenuates the amplified pressor response induced by activation of the metabolic and mechanical components of the reflex in rats after femoral artery occlusion. The suppressing effects of acute HT on the exaggerated exercise pressor reflex are likely mediated through a reduction in metabolites (e.g., ATP) stimulating the muscle afferent nerves in contracting muscle, but unlikely through direct alteration of P2X receptors per se.

Protective Mechanism and Treatment of Neurogenesis in Cerebral Ischemia

Stroke is the fifth leading cause of death worldwide and is a main cause of disability in adults. Neither currently marketed drugs nor commonly used treatments can promote nerve repair and neurogenesis after stroke, and the repair of neurons damaged by ischemia has become a research focus. This article reviews several possible mechanisms of stroke and neurogenesis and introduces novel neurogenic agents (fibroblast growth factors, brain-derived neurotrophic factor, purine nucleosides, resveratrol, S-nitrosoglutathione, osteopontin, etc.) as well as other treatments that have shown neuroprotective or neurogenesis-promoting effects.

Insights into the neuropathology of cerebral ischemia and its mechanisms

Cerebral ischemia is a result of insufficient blood flow to the brain. It leads to limited supply of oxygen and other nutrients to meet metabolic demands. These phenomena lead to brain damage. There are two types of cerebral ischemia: focal and global ischemia. This condition has significant impact on patient’s health and health care system requirements. Animal models such as transient occlusion of the middle cerebral artery and permanent occlusion of extracranial vessels have been established to mimic the conditions of the respective type of cerebral ischemia and to further understand pathophysiological mechanisms of these ischemic conditions. It is important to understand the pathophysiology of cerebral ischemia in order to identify therapeutic strategies for prevention and treatment. Here, we review the neuropathologies that are caused by cerebral ischemia and discuss the mechanisms that occur in cerebral ischemia such as reduction of cerebral blood flow, hippocampal damage, white matter lesions, neuronal cell death, cholinergic dysfunction, excitotoxicity, calcium overload, cytotoxic oedema, a decline in adenosine triphosphate (ATP), malfunctioning of Na+/K+-ATPase, and the blood-brain barrier breakdown. Altogether, the information provided can be used to guide therapeutic strategies for cerebral ischemia.

Maternal pomegranate juice intake and brain structure and function in infants with intrauterine growth restriction: A randomized controlled pilot study

Polyphenol-rich pomegranate juice has been shown to have benefit as a neuroprotectant in animal models of neonatal hypoxic-ischemia. No published studies have investigated maternal polyphenol administration as a potential neuroprotectant in at-risk newborns, such as those with intrauterine growth restriction (IUGR). This was a randomized, placebo-controlled, double-blind pilot study to investigate the impact of maternal pomegranate juice intake in pregnancies with IUGR, on newborn brain structure and function at term-equivalent age (TEA). Mothers with IUGR at 24-34 weeks' gestation were recruited from Barnes-Jewish Hospital obstetrical clinic. Consented mothers were randomized to treatment (8 oz. pomegranate juice) or placebo (8 oz. polyphenol-free juice) and continued to take juice daily from enrollment until delivery (mean 20.1 and 27.1 days, respectively). Infants underwent brain MRI at TEA (36-41 weeks' gestation). Brain measures were compared between groups including: brain injury score, brain metrics, brain volumes, diffusion tensor imaging and resting state functional connectivity. Statistical analyses were undertaken as modified intention-to-treat (including randomized participants who received their allocated intervention and whose infants received brain MRI) and per-protocol (including participants who strictly adhered to the protocol, based on metabolite status). Seventy-seven mothers were randomized to treatment (n = 40) or placebo (n = 37). Of these, 28 and 27 infants, respectively, underwent term-equivalent MRI. There were no group differences in brain injury, metrics or volumes. However, treatment subjects displayed reduced diffusivity within the anterior and posterior limbs of the internal capsule compared with placebo. Resting state functional connectivity demonstrated increased correlation and covariance within several networks in treatment subjects, with alterations most apparent in the visual network in per-protocol analyses. Direct effects on health were not found. In conclusion, maternal pomegranate juice intake in pregnancies with known IUGR was associated with altered white matter organization and functional connectivity in the infant brain, suggesting differences in brain structure and function following in utero pomegranate juice exposure, warranting continued investigation. Clinical trial registration. NCT00788866, registered November 11, 2008, initial participant enrollment August 21, 2012.

Noncoding RNAs as Molecular Targets of Resveratrol Underlying Its Anticancer Effects

Cancer is a significant disease burden worldwide. Chemotherapy is the mainstay of cancer treatment. Clinically used chemotherapeutic agents may elicit severe side effects. Remarkably, most of cancer cells develop chemoresistance after a period of treatment. Therefore, it is imperative to seek more effective agents without side effects. In recent years, increasing research efforts have attempted to identify natural agents that may be used alone or in combination with traditional therapeutics for cancer management. Resveratrol is a natural polyphenolic phytoalexin that can be found in various foods including blueberries, peanuts, and red wine. As a natural food ingredient, resveratrol possesses antioxidant, anti-inflammatory, and cardioprotective properties. Moreover, resveratrol exhibited promising effects in suppressing the initiation and progression of cancers. Noncoding RNAs (ncRNAs) have been universally accepted as vital regulators in cancer pathogenesis. The modulation of miRNAs and lncRNAs by resveratrol has been described. Thus, the mechanism involving the domination of ncRNA function is one of the keys to understand the anticancer effects of resveratrol. In this review, we focus on the antagonistic effects of resveratrol on cancer progression through regulation of miRNAs and lncRNAs. We also discuss the potential application of resveratrol in cancer management.

Neuroprotective effects of the new Na channel blocker rs100642 in global ischemic brain injury

INTRODUCTION

RS100642, a mexiletine analogue, is a novel sodium channel blocker with neuroprotective and antioxidant activities. The protectivity of RS100642, which has been shown against focal cerebral ischemia, was investigated in global cerebral ischemia in this study.

MATERIAL AND METHODS

Global cerebral ischemia was induced for five minutes in adult male Wistar Albino rats via the 4-vessel occlusion method. Intravenous administration of 1 mg/kg RS100642 following reperfusion for 30 min (RS100642 group) was compared with a sham treatment group (ischemia group) and nonischemized group (control) histologically based on morphology and caspase-3 immunohistochemistry, and biochemically based both on measurement of oxidative stress including malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities and on assessment of apoptosis including caspase-3 and -8 activities and tumor necrosis factor α (TNF-α) levels at the end of 6 h.

RESULTS

While the RS100642 group had significantly lower MDA levels and higher SOD activities than the sham treatment group (p < 0.05), GPx and CAT activities of the RS100642 and sham treatment groups were similar (p > 0.05) and significantly lower than those of the controls (p < 0.05). Necrosis and caspase-3 activity and immunoreactivity in the RS100642 group were significantly lower than those in the sham treatment group (p < 0.05), while there was no significant difference between groups regarding caspase-8 and TNF-α (p > 0.05).

CONCLUSIONS

Na⁺ channel blockade by RS100642 has remarkable neuroprotective effects following global brain ischemia/reperfusion damage. Further research is required to determine the optimum dose and time of administration.

Resveratrol mitigates the oxidative stress mediated by hypoxic-ischemic brain injury in neonatal rats via Nrf2/HO-1 pathway

CONTEXT

Hypoxic-ischemic encephalopathy (HIE) has a high morbidity and mortality rate. Resveratrol possesses numerous biological properties including antioxidant, anti-inflammatory and neuroprotective activities.

OBJECTIVE

The current experiment investigates the neuroprotective efficacy of resveratrol (RESV) against HIE by modulating Nrf2/HO-1 pathway in neonatal rats.

MATERIALS AND METHODS

Seven-day-old pups (n = 48) were divided into four groups. Group-I rats receiving 2% DMSO saline (sham), group-II rats underwent unilateral carotid artery ligation and hypoxia (92% N₂ and 8% O₂) for 2.5 h (hypoxia-ischemia; HI), group-III and IV rats received 20 (RESV 20 + HI) or 40 mg/kg (RESV 40 + HI; group-IV) of RESV via intraperitoneal injection (ip), respectively, for 7 days prior to HI induction.

RESULTS

Pre-treatment with RESV (20 or 40) markedly reduced (p < 0.01) the cerebral oedema (86.23-71.26 or 65.24%), infarct area (33.85-19.81 or 14.30%), lipid peroxidation products, inflammatory markers [IL-1β 186-110 or 82; IL-6 255-146 or 103; TNF-α 310-204 or 137; NF-κB 205-115 or 91) p65 subunit] and significantly restored (p < 0.01) the antioxidative status by enhancing the activities of glutathione peroxidase (GPx) 5.22-6.49 or 7.78; catalase (CAT) 51-55 or 59, superoxide dismutase (SOD) 2.5-3.05 or 3.25; through marked upregulation (p < 0.01) of heme oxygenase 1 (HO-1) 0.65-0.69 or 0.73; and nuclear factor erythroid 2 related factor 2 (Nrf2) 0.73-0.86 or 0.91.

DISCUSSION AND CONCLUSIONS

RESV displays its neurotherapeutic potential via upregulating the protein expression of Nrf2 and HO-1 signalling pathway and thereby attenuates oxidative stress and inflammatory response in HI-induced neonatal rats.

Ethyl-acetate fraction of Trichilia catigua protects against oxidative stress and neuroinflammation after cerebral ischemia/reperfusion

ETHNOPHARMACOLOGICAL RELEVANCE

Trichilia catigua A. Juss (Meliaceae) preparations have been used in folk medicine to alleviate fatigue, stress, and improve memory. Antinociceptive, antiinflammatory, and in vitro neuroprotective effects have been observed in animals. Cerebral ischemia/reperfusion (I/R) leads to severe neuropsychological deficits that are largely associated with oxidative stress, inflammation and neurodegeneration. We reported previously that an ethyl-acetate fraction (EAF) of T. catigua reduced brain ischemia-induced learning and memory impairments in the absence of histological protection.

AIM OF THE STUDY

Continuing those studies, here we aimed to investigate the antioxidant and antiinflammatory properties of T. catigua in an in vivo model of I/R.

MATERIAL AND METHODS

Rats were subjected to 15 min of brain ischemia (4-VO model) followed by up to 15 days of reperfusion. Vehicle was given by gavage 30 min before ischemia and at 1 h of reperfusion. In a first experiment, brain ischemia-induced changes in oxidative stress markers, i.e., reduced glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and protein carbonyl groups (PCGs) were measured on days 1, 3, and 5 post-ischemia. Similar time course analysis was done for neuroinflammation markers, i.e., microglia (OX42 immunorreactivity) and astrocytes (GFAP immunorreactivity), in the hippocampus. In a second experiment, the time points at which these markers of oxidative stress and neuroinflammation peaked were used to test the effects of T. catigua (400 mg/kg, p.o.).

RESULTS

Oxidative stress markers peaked on day 1 post-ischemia. GSH decreased (-23.2%) while GSSG increased (+ 71.1%), which yielded a significant reduction in the GSH/GSSG ratio (-39.1%). The activity of CAT was largely reduced by ischemia (-54.6% to -65.1%), while the concentration of PCG almost doubled in the brain of ischemic rats (+99.10%) in comparison to sham. Treatment with the EAF of T. catigua normalized these changes in oxidative markers to the control levels (GSH: +27.5%; GSSG: -23.8%; GSH/GSSG: +44.6%; PCG: -80.3%). In the hippocampus, neuroinflammation markers peaked on day 5 post-ischemia, with microglial and astrocytic responses increasing to 54.8% and 37.1%, respectively. The elevation in glial cells response was completely prevented by EAF.

CONCLUSION

These results demonstrate that T. catigua has both antioxidant and antiinflammatory activities after transient global cerebral ischemia in rats, which may contribute to the previously reported memory protective effect of T. catigua.

Orientin Attenuates Cerebral Ischemia/Reperfusion Injury in Rat Model through the AQP-4 and TLR4/NF-κB/TNF-α Signaling Pathway

BACKGROUND

Orientin has been reported to have extensive pharmaceutical effects of antioxidant, anti-inflammatory, antithrombosis, antiapoptosis, and so on. In the present study, we tried to investigate the protective effects of orientin on cerebral ischemia-reperfusion (I/R) injury and explored the possible mechanisms.

METHODS

Middle cerebral artery occlusion rat model was established and then treated with low, middle, and high concentrations of orientin, respectively, with edaravone as a positive control. The treatment effect of orientin was evaluated by measuring the neurological deficit score, cerebral infarction, brain edema, oxidative stress, excitatory amino acids release, the expression levels of aquaporin-4 (AQP-4), and related inflammatory molecules using different methods including immunohistochemistry, enzyme-linked immunosorbent assay, real-time PCR, and western blot. Moreover, morphological and structural changes were also observed by hematoxylin-eosin staining and transmission electron microscope.

RESULTS

Orientin provided a significant reduction on neurological deficits, cerebral infarction, cerebral edema, oxidative damage, and neurotoxicity of excitatory amino acids compared to model group (P < .05) in a dose-dependent manner. In addition, orientin substantially downregulated AQP-4 and inflammatory factors expression (P < .05) and improved cell morphology and structure in rats following I/R injury.

CONCLUSION

Orientin was able to mediate noticeable protection against cerebral I/R injury through the attenuation of oxidative stress and neurotoxicity of amino acids and inhibiting the upregulation of AQP-4 and inflammatory cytokines.

Mitochondrial function in hypoxic ischemic injury and influence of aging

Mitochondria are a major target in hypoxic/ischemic injury. Mitochondrial impairment increases with age leading to dysregulation of molecular pathways linked to mitochondria. The perturbation of mitochondrial homeostasis and cellular energetics worsens outcome following hypoxic-ischemic insults in elderly individuals. In response to acute injury conditions, cellular machinery relies on rapid adaptations by modulating posttranslational modifications. Therefore, post-translational regulation of molecular mediators such as hypoxia-inducible factor 1α (HIF-1α), peroxisome proliferator-activated receptor γ coactivator α (PGC-1α), c-MYC, SIRT1 and AMPK play a critical role in the control of the glycolytic-mitochondrial energy axis in response to hypoxic-ischemic conditions. The deficiency of oxygen and nutrients leads to decreased energetic reliance on mitochondria, promoting glycolysis. The combination of pseudohypoxia, declining autophagy, and dysregulation of stress responses with aging adds to impaired host response to hypoxic-ischemic injury. Furthermore, intermitochondrial signal propagation and tissue wide oscillations in mitochondrial metabolism in response to oxidative stress are emerging as vital to cellular energetics. Recently reported intercellular transport of mitochondria through tunneling nanotubes also play a role in the response to and treatments for ischemic injury. In this review we attempt to provide an overview of some of the molecular mechanisms and potential therapies involved in the alteration of cellular energetics with aging and injury with a neurobiological perspective.

Targeting PRAS40 for multiple diseases

Proline-rich Akt substrate 40kDa (PRAS40) bridges cell signaling between protein kinase B (Akt) and the mammalian target of rapamycin complex 1 (mTORC1). Both Akt and mTORC1 can phosphorylate PRAS40. As a negative regulator of mTORC1, PRAS40 prevents the binding of mTOR to its substrates. The phosphorylation of PRAS40 results in its dissociation from mTORC1 and enhanced mTOR activation. PRAS40 in conjunction with mTORC1 has been closely associated with programmed cell death and is implicated in diabetes mellitus (DM), cardiovascular diseases, cancer, and neurological diseases. Thus, targeting PRAS40 might hold great promise for innovative therapeutic strategies for these diseases.

Protecting the BBB endothelium against cigarette smoke-induced oxidative stress using popular antioxidants: Are they really beneficial?

Blood Brain Barrier (BBB) exposed to realistic concentrations (comparable to a chronic heavy smoker) of Cigarette Smoke Extract (CSE) triggers a strong endothelial inflammatory response which can lead to the onset of neurological disorders. The involvement of Reactive Oxygen Species (ROS) in this inflammatory cascade is evident from the up-regulation of nuclear factor erythroid 2 related factor 2 (Nrf-2), a transcription factor involved in anti-oxidant response signaling in CSE exposed endothelial cells. We have shown that pre-treatment with α-tocopherol and/or ascorbic acid is highly protective for the BBB, thus suggesting that, prophylactic administration of antioxidants can reduce CSE and/or inflammatory-dependent BBB damage. We have assessed and ranked the protective effects of 5 popular OTC antioxidants (Coenzyme Q10, melatonin, glutathione, lipoic acid and resveratrol) against CSE-induced BBB endothelial damage using hCMEC/D3 cells. The analysis of pro-inflammatory cytokines release by ELISA revealed that resveratrol, lipoic acid melatonin and Co-Q10 inhibited the BBB endothelial release of pro-inflammatory cytokines IL-6 and IL-8, reduced (not Co-Q10) CSE-induced up-regulation of Platelet Cell Adhesion Molecule-1 (PECAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1) & E-selectin and inhibited monocytes-endothelial cell adhesion. The anti-inflammatory effects correlated with the anti-oxidative protection endowed by these compounds as evidenced by upregulation of NADPH: Quinone Oxidoreductase 1 (NQO1) and reduced cellular oxidative stress. CSE-induced release of Vascular Endothelial Growth Factor (VEGF) was inhibited by all tested compounds although the effect was not strictly dose-dependent. Further in vivo studies are required to validate our results and expand our current study to include combinatorial treatments.

The effect of resveratrol on pharmacokinetics of aripiprazole in vivo and in vitro

1. The objective of this study were to investigate the effect of orally administered resveratrol on the pharmacokinetics of aripiprazole (APZ) in rat, and the inhibitory effects of resveratrol on APZ dehydrogenation activity in liver microsomes and human cytochrome P450 3A4 and 2D6. 2. Twenty-five healthy male Sprague-Dawley rats were randomly divided into five groups: A (control group), B (multiple dose of 200 mg/kg resveratrol), C (multiple dose of 100 mg/kg resveratrol), D (a single dose of 200 mg/kg resveratrol) and E (a single dose of 100 mg/kg resveratrol). A single dose of 3 mg/kg APZ administered orally 30 min after administration of resveratrol. In addition, CYP2D6*1, CYP3A4*1, human and rat liver microsomes were performed to determine the effect of resveratrol on the metabolism of APZ in vitro. 3. The multiple dose of 200 or 100 mg/kg resveratrol significantly increased the AUC and Cmax of APZ. The resveratrol also obviously decreased the CL, but without any significant difference on t1/2 in vivo. On the other hand, resveratrol showed inhibitory effect on CYP3A4*1, CYP2D6*1, human and rat microsomes, the IC50 of resveratrol was 6.771, 87.87, 45.11 and 35.59 μmol l(-1), respectively. 4. Those results indicated more attention should be paid when APZ was administrated combined with resveratrol.

Ammonia impairs glutamatergic communication in astroglial cells: protective role of resveratrol

Ammonia is a key toxin in the precipitation of hepatic encephalopathy (HE), a neuropsychiatric disorder associated with liver failure. In response to ammonia, various toxic events are triggered in astroglial cells, and alterations in brain glutamate communication are common. Resveratrol is a polyphenolic compound that has been extensively studied in pathological events because it presents several beneficial effects, including some in the central nervous system (CNS). We previously described that resveratrol is able to significantly modulate glial functioning and has a protective effect during ammonia challenge in vitro. In this study, we addressed the mechanisms by which resveratrol can protect C6 astroglial cells from glutamatergic alterations induced by ammonia. Resveratrol was able to prevent all the effects triggered by ammonia: (i) decrease in glutamate uptake activity and expression of the EAAC1 glutamate transporter, the main glutamate transporter present in C6 cells; (ii) increase of glutamate release, which was also dependent on the activation of the Na(+)-K(+)-Cl(-) co-transporter NKCC1; (iii) reduction in GS activity and intracellular GSH content; and (iv) impairment of Na(+)K(+)-ATPase activity. Interestingly, resveratrol, per se, also positively modulated the astroglial functions evaluated. Moreover, we demonstrated that heme oxygenase 1 (HO1), an enzyme that is part of the cellular defense system, mediated some of the effects of resveratrol. In conclusion, the mechanisms of the putative protective role of resveratrol against ammonia toxicity involve the modulation of pathways and molecules related to glutamate communication in astroglial cells.

Resveratrol neuroprotection in stroke and traumatic CNS injury

Resveratrol, a stilbene formed in many plants in response to various stressors, elicits multiple beneficial effects in vertebrates. Particularly, resveratrol was shown to have therapeutic properties in cancer, atherosclerosis and neurodegeneration. Resveratrol-induced benefits are modulated by multiple synergistic pathways that control oxidative stress, inflammation and cell death. Despite the lack of a definitive mechanism, both in vivo and in vitro studies suggest that resveratrol can induce a neuroprotective state when administered acutely or prior to experimental injury to the CNS. In this review, we discuss the neuroprotective potential of resveratrol in stroke, traumatic brain injury and spinal cord injury, with a focus on the molecular pathways responsible for this protection.

Organ-Protective Effects of Red Wine Extract, Resveratrol, in Oxidative Stress-Mediated Reperfusion Injury

Resveratrol, a polyphenol extracted from red wine, possesses potential antioxidative and anti-inflammatory effects, including the reduction of free radicals and proinflammatory mediators overproduction, the alteration of the expression of adhesion molecules, and the inhibition of neutrophil function. A growing body of evidence indicates that resveratrol plays an important role in reducing organ damage following ischemia- and hemorrhage-induced reperfusion injury. Such protective phenomenon is reported to be implicated in decreasing the formation and reaction of reactive oxygen species and pro-nflammatory cytokines, as well as the mediation of a variety of intracellular signaling pathways, including the nitric oxide synthase, nicotinamide adenine dinucleotide phosphate oxidase, deacetylase sirtuin 1, mitogen-activated protein kinase, peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, hemeoxygenase-1, and estrogen receptor-related pathways. Reperfusion injury is a complex pathophysiological process that involves multiple factors and pathways. The resveratrol is an effective reactive oxygen species scavenger that exhibits an antioxidative property. In this review, the organ-protective effects of resveratrol in oxidative stress-related reperfusion injury will be discussed.

Neuroprotective effects of quercetin in a mouse model of brain ischemic/reperfusion injury via anti-apoptotic mechanisms based on the Akt pathway

The present study provided experimental evidence for the neuroprotective effects of quercetin using a rat model of global brain ischemic/reperfusion (I/R) injury. Pre‑treatment with quercetin (5 or 10 mg/kg orally (p.o.); once daily) induced a dose‑dependent reduction in I/R‑induced hippocampal neuron cell loss, with 10 mg/kg/day being the lowest dose that achieved maximal neuroprotection. Administration of 10 mg/kg quercetin over at least 3 days prior to I/R was required to improve the survival rate of I/R rats. Fluorescence‑assisted cell sorting, hematoxylin and eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling indicated neuronal cell loss in the CA1 hippocampus. Rats that had undergone transient global cerebral ischemia for 15 min followed by 1 h of reperfusion exhibited a significant increase in reactive oxygen species (ROS) production in the hippocampus. The I/R‑induced ROS overproduction in the hippocampus at 1, 12 and 24 h following I/R was significantly decreased by quercetin pre‑treatment. Western blot analysis revealed that the neuroprotective effects of quercetin (5 and 10 mg/kg/day, p.o.) were associated with an upregulation of the I/R‑induced suppression of B‑cell lymphoma‑2 (Bcl‑2), Bcl extra large and survivin expression as well as phosphorylation of Bcl‑2‑associated death promoter. Furthermore, the neuroprotective effects of quercetin (5, 10 mg/kg/day) in the brain were associated with an upregulation of Akt signaling. These findings suggested that the inhibition of I/R‑induced brain injury by quercetin likely involves a transcriptional mechanism to enhance anti‑apoptotic signaling.

Chronic treatment with resveratrol, a natural polyphenol found in grapes, alleviates oxidative stress and apoptotic cell death in ovariectomized female rats subjected to chronic cerebral hypoperfusion

OBJECTIVES

Resveratrol appears to have neuroprotective potential in various animal models of brain disorders including cerebral ischemia and neurodegenerative diseases. Chronic cerebral hypoperfusion is a well-known pathological condition contributing to the neurodegenerative diseases such as vascular dementia. Purpose of the present study is to evaluate the possible therapeutic potential of resveratrol in a model of vascular dementia of ovariectomized female rats. Assessment of the potential was based on the determination of brain oxidative status, caspase-3 level, glial fibrillary acidic protein (GFAP), and neuronal damage on hippocampus and cerebral cortex.

METHODS

For creating the model of chronic cerebral hypoperfusion, ovariectomized female Wistar rats were subjected to the modified two vessel occlusion method, with the right common carotid artery being occluded first and the left one a week later.

RESULTS

At the 15th day following the ligation, neuronal damage was accompanied by the increased immunoreactivities of both GFAP and caspase-3, and significant neurodegeneration was evident in the hippocampus and cortex, all of which were significantly alleviated with resveratrol treatment (10 mg/kg). Biochemical analysis revealed that the resveratrol treatment decreased lipid peroxidation and restored reduced glutathione level as well.

DISCUSSION

The collected data of the present study suggest that the administration of resveratrol may provide a remarkable therapeutic benefit for vascular dementia, which is most likely related to the prevention of both apoptotic cell death and oxidative stress. We believe that therapeutic efficacy of resveratrol deserves to be tested for potential clinical application in postmenopausal elderly women suffering from vascular dementia.

The accumulation of brain water-free sodium is associated with ischemic damage independent of the blood pressure in female rats

Estrogen deficiency worsens ischemic stroke outcomes. In ovariectomized (OVX(+)) rats fed a high-salt diet (HSD), an increase in the body Na(+)/water ratio, which characterizes water-free Na(+) accumulation, was associated with detrimental vascular effects independent of the blood pressure (BP). We hypothesized that an increase in brain water-free Na(+) accumulation is associated with ischemic brain damage in OVX(+)/HSD rats. To test our hypothesis we divided female Wistar rats into 4 groups, OVX(+) and OVX(-) rats fed HSD or a normal diet (ND), and subjected them to transient cerebral ischemia. The brain Na(+)/water ratio was increased even in OVX(+)/ND rats and augmented in OVX(+)/HSD rats. The increase in the brain Na(+)/water ratio was positively correlated with expansion of the cortical infarct volume without affecting the BP. Interestingly, OVX(+) was associated with the decreased expression of ATP1α3, a subtype of the Na(+) efflux pump. HSD increased the expression of brain Na(+) influx-related molecules and the mineralocorticoid receptor (MR). The pretreatment of OVX(+)/HSD rats with the MR antagonist eplerenone reduced brain water-free Na(+) accumulation, up-regulated ATP1α3, down-regulated MR, and reduced the cortical infarct volume. Our findings show that the increase in the brain Na(+)/water ratio elicited by estrogen deficiency or HSD is associated with ischemic brain damage BP-independently, suggesting the importance of regulating the accumulation of brain water-free Na(+). The up-regulation of ATP1α3 and the down-regulation of MR may provide a promising therapeutic strategy to attenuate ischemic brain damage in postmenopausal women.

Ketones prevent oxidative impairment of hippocampal synaptic integrity through KATP channels

Dietary and metabolic therapies are increasingly being considered for a variety of neurological disorders, based in part on growing evidence for the neuroprotective properties of the ketogenic diet (KD) and ketones. Earlier, we demonstrated that ketones afford hippocampal synaptic protection against exogenous oxidative stress, but the mechanisms underlying these actions remain unclear. Recent studies have shown that ketones may modulate neuronal firing through interactions with ATP-sensitive potassium (K_ATP) channels. Here, we used a combination of electrophysiological, pharmacological, and biochemical assays to determine whether hippocampal synaptic protection by ketones is a consequence of K_ATP channel activation. Ketones dose-dependently reversed oxidative impairment of hippocampal synaptic integrity, neuronal viability, and bioenergetic capacity, and this action was mirrored by the K_ATP channel activator diazoxide. Inhibition of K_ATP channels reversed ketone-evoked hippocampal protection, and genetic ablation of the inwardly rectifying K⁺ channel subunit Kir6.2, a critical component of K_ATP channels, partially negated the synaptic protection afforded by ketones. This partial protection was completely reversed by co-application of the K_ATP blocker, 5-hydoxydecanoate (5HD). We conclude that, under conditions of oxidative injury, ketones induce synaptic protection in part through activation of K_ATP channels.

The pharmacology of resveratrol in animals and humans

In addition to thousands of research papers related to resveratrol (RSV), approximately 300 review articles have been published. Earlier research tended to focus on pharmacological activities of RSV related to cardiovascular systems, inflammation, and carcinogenesis/cancer development. More recently, the horizon has been broadened by exploring the potential effect of RSV on the aging process, diabetes, neurological dysfunction, etc. Herein, we primarily focus on the in vivo pharmacological effects of RSV reported over the past 5 years (2009-2014). In addition, recent clinical intervention studies performed with resveratrol are summarized. Some discrepancies exist between in vivo studies with animals and clinical studies, or between clinical studies, which are likely due to disparate doses of RSV, experimental settings, and subject variation. Nevertheless, many positive indications have been reported with mammals, so it is reasonable to advocate for the conduct of more definitive clinical studies. Since the safety profile is pristine, an added advantage is the use of RSV as a dietary supplement. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.

Progress on the protective effect of compounds from natural medicines on cerebral ischemia

The treatment of cerebral ischemic disease by natural medicines has a long history, and has accumulated a rich theoretical knowledge and treatment experience. The objective of this review is to critically evaluate the experimental research situation of the protective effect of the individual compounds from natural medicine on cerebral ischemia in the past ten years, emphasizing the major mechanisms underlying cerebral ischemic pathophysiology. Sixteen representative compounds from natural medicines which are often used to treat stroke are discussed. The results indicate that these components possess a protective effect on cerebral ischemia, and that these components have different mechanisms, including inhibiting excitotoxicity by ginkgolide B, antiapoptosis of breviscapine, influencing astrocytic activation and proliferation of tanshinone IIA, influencing free radicals by ginsenoside Rd, impairing blood-brain barrier disruption by baicalin, and the anti-inflammatory activity of tetramethylpyrazine. Moreover, some components have multiple neuroprotective mechanisms. Therefore, the combination of individual compounds from natural medicines, considering the mechanisms of cerebral ischemia, may be beneficial to patients with cerebral ischemia in the future. This approach will provide a direction for the further application and exploitation of new drug development in the treatment of cerebral ischemia.

Advances in Herbal Medicine for Treatment of Ischemic Brain Injury

Ischemic brain injury is one of the leading causes of death worldwide and has attracted a lot of attention in the field of drug discovery. Cerebral ischemia is a complex pathological process involving a series of mechanisms, including generation of free radicals, oxidative stress, disruption of the membrane function, release of neurotransmitters and apoptosis. Thrombolytic therapy is the most effective therapeutic strategy, but the benefits are far from being absolute. Increased attention in the field of drug discovery has been focused on using natural compounds from traditional medicinal herbs for neuroprotection, which appears to be a promising therapeutic option for cerebral ischemia with minimal systemic adverse effects that could limit their long term use. The scenario calls for extensive investigations which can result in the development of lead molecules for neuroprotection in the future. In this context, the present review focuses on possible mechanisms underlying the beneficial effects of herbal drugs in patients with cerebral ischemic injury. Natural compounds have been demonstrated to have neurofunctional regulatory actions with antioxidative, anti-inflammatory, calcium antagonizing and anti-apoptotic activities. Among the several leads obtained from plant sources as potential neuroprotective agents, resveratrol, EGb761, curcumin and epigallocatechin-3-gallate have shown significant therapeutic benefits in cerebral ischemic conditions. However, ligustilide, tanshinone, scutellarin and shikonin are the few lead molecules which are under investigation for treatment of cerebral ischemia.

Sarcosine preconditioning induces ischemic tolerance against global cerebral ischemia

Brain ischemic tolerance is an endogenous protective mechanism activated by a preconditioning stimulus that is closely related to N-methyl-d-aspartate receptor (NMDAR). Glycine transporter type 1 (GlyT-1) inhibitors potentiate NMDAR and suggest an alternative strategy for brain preconditioning. The aim of this work was to evaluate the effects of brain preconditioning induced by sarcosine, a GlyT-1 inhibitor, against global cerebral ischemia and its relation to NMDAR. Sarcosine was administered over 7 days (300 or 500 mg/kg/day, ip) before the induction of a global cerebral ischemia model in Wistar rats (male, 8-week-old). It was observed that sarcosine preconditioning reduced cell death in rat hippocampi submitted to cerebral ischemia. Hippocampal levels of glycine were decreased in sarcosine-treated animals, which was associated with a reduction of [(3)H] glycine uptake and a decrease in glycine transporter expression (GlyT-1 and GlyT-2). The expression of glycine receptors and the NR1 and NR2A subunits of NMDAR were not affected by sarcosine preconditioning. However, sarcosine preconditioning reduced the expression of the NR2B subunits of NMDAR. In conclusion, these data demonstrate that sarcosine preconditioning induces ischemic tolerance against global cerebral ischemia and this neuroprotective state is associated with changes in glycine transport and reduction of NR2B-containing NMDAR expression.

In vitro effects of resveratrol on oxidative stress in diabetic platelets

To evaluate the in vitro effects of resveratrol (RSV) incubation on platelets from compensated and decompensated diabetic patients in order to use it as an adjuvant therapy. The study was performed on 77 diabetic patients and divided into two phases: 29 compensated and 48 decompensated diabetic platelets were analyzed at recruitment (T₀) and after in vitro RSV incubation (20 μg/ml) for 3 h at 37 °C (T₁). Lipoperoxide and nitric oxide (NO) levels, superoxide dismutase (SOD) and Na(+)/K(+) ATPase activities, total antioxidant capacity (TAC), and membrane fluidity tested by anisotropy of fluorescent probes TMA-DPH and DPH were determined. In vitro RSV incubation counteracts oxidative damage associated with diabetes and its complications; it is able to improve platelet function through augmented membrane fluidity and Na(+)/K(+) ATPase activity; it enhances antioxidant systems' functionality by increasing NO levels, SOD activity, and TAC and by decreasing lipoperoxide levels in both compensated and decompensated patients. Such platelet functionality enhancement suggests a new method of secondary prevention of complications associated with platelet dysfunction. Being free from one of the major risks associated with many antidiabetic agents, it can be assumed that RSV utilization in the diabetic diet may have a preventive and protective role in the progression of diabetic oxidative damage.

Comparative analysis of the neuroprotective effects of ginsenosides Rg1 and Rb1 extracted from Panax notoginseng against cerebral ischemia

Panax notoginseng, a traditional Chinese medicine, has been used for thousands of years to treat ischemic patients. More than 20 saponin components have been isolated from P. notoginseng root and identified chemically. However, these different chemical components have different roles. In this study we compared the neuroprotective mechanisms of ginsenosides Rg1, Rb1, Rg1/Rb1, and panax notoginsenoside (PNS) against injuries caused by cerebral ischemia-reperfusion (I/R). Our results show that all of these treatments significantly reduced infarction volume and alleviated neurological deficits caused by cerebral I/R. The increase in malondialdehyde (MDA) concentration was inhibited by these treatments in the hippocampus. The decreased expressions of thioredoxin-1 (Trx-1), copper-zinc superoxide dismutase (SOD-1), protein kinase B (PKB/Akt), and nuclear factor-kappa B (NF-κB) caused by cerebral I/R were restored by these treatments. The expression of heat shock protein 70 (HSP70) was enhanced in the middle cerebral artery occlusion (MCAO) group, as well as in all of the treatment groups. These results suggest that Rg1 and Rb1 have similar roles in protecting the brain from ischemic damage; however, neither Rg1/Rb1 nor PNS have synergistic effects, thus either Rg1 or the Rb1 monomer should be considered as a pharmacological neuroprotective strategy for use in the case of ischemic stroke.

WISP1 neuroprotection requires FoxO3a post-translational modulation with autoregulatory control of SIRT1

As a member of the secreted extracellular matrix associated proteins of the CCN family, Wnt1 inducible signaling pathway protein 1 (WISP1/CCN4) is garnering increased attention not only as a potent proliferative entity, but also as a robust cytoprotective agent during toxic insults. Here we demonstrate that WISP1 prevents forkhead transcription factor FoxO3a mediated caspase 1 and caspase 3 apoptotic cell death in primary neurons during oxidant stress. Phosphoinositide 3-kinase (PI 3-K) and protein kinase B (Akt1) are necessary for WISP1 to foster posttranslational phosphorylation of FoxO3a and sequester FoxO3a in the cytoplasm of neurons with protein 14-3-3. Through an autoregulatory loop, WISP1 also minimizes deacytelation of FoxO3a, prevents caspase 1 and 3 activation, and promotes an effective neuroprotective level of SIRT1 activity through SIRT1 nuclear trafficking and prevention of SIRT1 caspase degradation. Elucidation of the critical pathways of WISP1 that determine neuronal cell survival during oxidative stress may offer novel therapeutic avenues for neurodegenerative disorders.

Melatonin-based therapeutics for neuroprotection in stroke

The present review paper supports the approach to deliver melatonin and to target melatonin receptors for neuroprotection in stroke. We discuss laboratory evidence demonstrating neuroprotective effects of exogenous melatonin treatment and transplantation of melatonin-secreting cells in stroke. In addition, we describe a novel mechanism of action underlying the therapeutic benefits of stem cell therapy in stroke, implicating the role of melatonin receptors. As we envision the clinical entry of melatonin-based therapeutics, we discuss translational experiments that warrant consideration to reveal an optimal melatonin treatment strategy that is safe and effective for human application.