Neuroprotective effect of resveratrol against prenatal stress induced cognitive impairment and possible involvement of Na(+), K(+)-ATPase activity

Therapeutic effects of resveratrol on memory deficits in offspring of sleep-deprived rats: Involvement of hippocampal BDNF-TrkB pathways

BACKGROUND

Maternal sleep deprivation (MSD) is a significant public health issue that adversely affects neurogenesis and synaptic plasticity in offspring, resulting in cognitive deficits in learning and memory. Resveratrol, an antioxidant with neuroprotective and anti-inflammatory properties, may help mitigate these effects. This study investigates resveratrol's potential to counteract the negative impacts of MSD on neurodevelopment in male Wistar rat offspring.

METHODS

Ninety-six male Wistar rat offspring and 36 pregnant rats were used. Total MSD was induced using the water box device on gestational days 7, 11, and 17. Pregnant rats received resveratrol at doses of 25 or 50 mg/kg every 12 h during the sleep deprivation period. After parturition, offspring were divided into 12 groups for assessment at two months of age. Social interaction tests evaluated social memory, while the Morris water maze test assessed spatial learning and memory. Brain samples were prepared for Nissl staining, and brain-derived neurotrophic factor (BDNF) and tyrosine-protein kinase (TrkB) expression levels in the hippocampus were measured using western blotting.

RESULTS

Our findings indicate that the MSD group exhibited decreased BDNF/TrkB expression and increased neuronal damage in the hippocampus, which led to disrupted spatial and social memory compared to the control group. Subsequently, resveratrol administration, especially at a dose of 50 mg/kg during pregnancy, significantly reversed MSD's detrimental effects on cognitive function in offspring.

CONCLUSION

Our results provide novel evidence of resveratrol's neuroprotective effects in rat pregnancy models of MSD, suggesting its potential for developing therapeutic interventions targeting prenatal neurodegenerative disorders.

Effect of Resveratrol on Pregnancy, Prenatal Complications and Pregnancy-Associated Structure Alterations

Adverse pregnancy outcomes are considered significant health risks for pregnant women and their offspring during pregnancy and throughout their lifespan. These outcomes lead to a perturbated in-utero environment that impacts critical phases of the fetus's life and correlates to an increased risk of chronic pathological conditions, such as diabetes, obesity, and cardiovascular diseases, in both the mother's and adult offspring's life. The dietary intake of naturally occurring antioxidants promotes health benefits and disease prevention. In this regard, maternal dietary intake of polyphenolic antioxidants is linked to a reduced risk of maternal obesity and cardio-metabolic disorders, positively affecting both the fetus and offspring. In this work, we will gather and critically appraise the current literature highlighting the effect/s of the naturally occurring polyphenol antioxidant resveratrol on oxidative stress, inflammation, and other molecular and physiological phenomena associated with pregnancy and pregnancy conditions, such as gestational diabetes, preeclampsia, and preterm labor. The resveratrol impact on prenatal complications and pregnancy-associated structures, such as the fetus and placenta, will also be discussed. Finally, we will draw conclusions from the current knowledge and provide future perspectives on potentially exploiting resveratrol as a therapeutic tool in pregnancy-associated conditions.

Resveratrol Ameliorates Trigeminal Neuralgia-Induced Cognitive Deficits by Regulating Neural Ultrastructural Remodelling and the CREB/BDNF Pathway in Rats

Chronic pain often leads to cognitive impairment. Resveratrol (Res), a natural polyphenol existing in Polygonum cuspidatum, has been widely investigated for its antinociceptive, anti-inflammatory, and neuroprotective properties. Our aim was to explore the ameliorating effects of resveratrol on pain-related behaviors and learning and memory deficits induced by cobra venom-induced trigeminal neuralgia (TN). The TN model of rats was established by injecting cobra venom solution beneath the epineurium of the infraorbital nerve. Resveratrol was intragastrically administered at a dose of 40 mg/kg twice daily beginning on postoperative day 15. CREB inhibitor 666-15 was intraperitoneally administered at a dose of 10 mg/kg from POD 35-42 after morning resveratrol treatment. Mechanical allodynia was measured via von Frey filaments. Rat free movement was videotaped and analyzed. Spatial learning and memory were evaluated via the Morris water maze test. Ultrastructures of the hippocampal DG region and infraorbital nerve were observed by transmission electron microscopy. We found that resveratrol alleviated TN-induced allodynia, ameliorated learning and memory deficits, restored the ultrastructure of hippocampal neurons and synapses, repaired the damaged myelin sheath of the infraorbital nerve, and activated the CREB/BDNF pathway in the hippocampus of TN rats. CREB inhibitor administration suppressed the resveratrol-rescued abnormal hippocampal ultrastructural changes and aggravated spatial learning and memory impairment by inhibiting CREB/BDNF pathway activation in the hippocampus. Our findings indicated that resveratrol alleviated pain and improved cognitive deficits, probably by regulating neural ultrastructure remodelling and the CREB/BDNF pathway.

In vivo neurotoxic effects of emamectin benzoate in male mice: evaluation with enzymatic and biomolecular multi-biomarkers

The study of the toxic effects of emamectin benzoate (EMB) was conducted in male mice. Mice were randomly divided into 4 groups; control group, EMB25 group (1/30 LD₅₀ = 25 mg/kg/day), EMB50 group (1/15 LD₅₀ = 50 mg/kg/day), and EMB100 group (1/7.5 LD₅₀ = 100 mg/kg/day). Control group received water (placebo), and EMB groups were administered by oral gavage for 14 days. The superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) enzyme activities, thiobarbituric acid reactive substance (TBARS) and protein carbonyl (PC) levels, and adenosine triphosphatase (ATPases) enzymes, which are ion transport enzymes (Na⁺/K⁺ ATPase, Ca⁺² ATPase, Mg⁺² ATPase), acetylcholinesterase (AChE, neurotoxicity biomarker), and myeloperoxidase (MPO) enzyme activities (inflammatory biomarker), were measured by spectrophotometric methods. 8-Hydroxy-2'-deoxyguanosine level (8-OHdG, DNA oxidation biomarker) was measured by enzyme-linked immunosorbent analysis (ELISA) technique. The results showed a decrease in SOD, CAT and GPx enzyme activities in the brain tissue and an increase in GST enzyme activity in the EMB groups compared to the control group. Meanwhile, the enzyme activities of the ion transport enzymes Na⁺/K⁺ ATPase, Ca⁺² ATPase, and Mg⁺² ATPase, and AChE enzyme activity showed significant inhibition. In addition, MPO enzyme activity, 8-OHdG, PC, and TBARS levels were increased. The results showed that dose-dependent EMB exposure induced different physiological processes with enzymatic and biomolecular multi-biomarkers in the brain tissue of male mice and caused neurotoxic effects.

Effects of trophic 2,2', 4,4'-tetrabromodiphenyl ether (BDE-47) exposure in Oreochromis niloticus: A multiple biomarkers analysis

Polybrominated diphenyl esters are emerging environmental contaminants with few toxicological data, being a concern for the scientific community. This study evaluated the effects of BDE-47 on the health of Oreochromis niloticus fish. The animals were exposed to three doses of BDE-47 (0, 0.253, 2.53, 25.3 ng g^-1) every 10 days, for 80 days. The BDE-47 affected the hepatosomatic and gonadosomatic index in female and the condition factor by intermediate dose in both sexes. The levels of estradiol decreased and the T4 are increased, but the vitellogenin production was not modulated in male individuals. Changes in AChE, GST, LPO and histopathology were observed while the integrated biomarker response index suggests that the lowest dose of BDE-47 compromised the activity of antioxidant enzymes. The oral exposure to BDE-47 in environmental concentrations is toxic to O. niloticus and the use of multiple biomarkers is an attribution in ecotoxicology studies and biomonitoring programs.

Effects on the survival rates, hematological parameters, and neurotransmitters in olive flounders, Paralichthys olivaceus, reared in bio-floc and seawater by Streptococcus iniae challenge

Bacterial infections cause huge losses to aquaculture globally, and increased antibiotic resistance means that alternative methods of reducing mortality from bacterial diseases are required. We compared the resistance of Juvenile olive flounders, Paralichthys olivaceus, to Streptococcus iniae between those reared in biofloc and seawater conditions for ten months. Experimental fish were challenged with S. iniae at concentrations of 0, 3.36 × 10⁶, 3.36 × 10⁷, 3.36 × 10⁸, and 3.36 × 10⁹ colony forming units (CFU)/g fish for 96 h to evaluate the difference in S. iniae susceptibility of flounders reared in biofloc and seawater. The 96 h lethal concentration 50% (LC₅₀) of fish injected with S. iniae was 2.41 × 10⁹ CFU/g fish in biofloc and 1.51 × 10⁸ CFU/g fish in seawater. Hematological parameters such as hemoglobin and hematocrit significantly decreased when fish were challenged by S. iniae. Plasma components such as calcium, glucose, cholesterol, total protein, GOT, GPT, and ALP were significantly altered by S. iniae infection and acetylcholinesterase activity was significantly inhibited. These results indicate that S. iniae infection affects the survival rates, hematological parameters, and neurotransmitter levels of flounders reared in biofloc and seawater, and that S. iniae susceptibility was higher in flounders reared in seawater than those reared in biofloc.

Enhanced and sustainable pretreatment for bioconversion and extraction of resveratrol from peanut skin using ultrasound-assisted surfactant aqueous system with microbial consortia immobilized on cellulose

In this study, the ultrasound-assisted surfactant aqueous system coupled with microbial consortia immobilized by cellulose has been created as an enhanced and sustainable method for the bioconversion and extraction of resveratrol from peanut skin. Based on central composite design, and several single-factor experiments, we derived the optimal bioconversion and extraction system. Microbial consortia consist of Yeast CICC 1912, Aspergillus oryzae 3.951 and Aspergillus niger 3.3148 were chosen to be immobilized using cellulose. Other treatment conditions include concentration of surfactant as 3% (w/v), temperature as 30 °C, time as 36 h, ultrasonic power as 250 W and liquid to solid ratio as 25:1 mL/g. Under these conditions, we achieved a promising yield of resveratrol 96.58 μg/g, which is 4.02 folds compared to the untreated sample. This sustainable and green method not only enhanced the production of resveratrol but also improved the safety and reliability of the bioconversion and extraction process. Our novel method has shown great potential to realize large-scale bioconversion and extraction of bioactive compounds from plant waste.

Improved extraction of resveratrol and antioxidants from grape peel using heat and enzymatic treatments

BACKGROUND

Resveratrol, an extensively recognized phytochemical that belongs to the stilbene family, is abundant in grape peel which is discarded as a by-product during grape juice processing.

RESULTS

In this study, we established that pre-heating grape peel above 75 °C significantly improved the extractability of resveratrol and its glucoside piceid. In particular, thermal heating of grape peel at 95 °C for 10 min, followed by treatment with a mixture of exo-1,3-β-glucanase and pectinases at 50 °C for 60 min, dramatically increased the conversion of piceid into resveratrol and the overall extractability of this phytochemical by 50%. Furthermore, thermal pre-treatment promoted a substantial increase in the total phenol, flavonoid, and anthocyanin concentrations in the grape peel extract. Ultimately, resveratrol-enriched grape peel extract significantly augmented the antioxidant response in vitro, possibly by attenuating the accumulation of intracellular reactive oxygen species via the Nrf2 signaling pathway.

CONCLUSION

The method developed in this study for preparing grape peel extract introduces a potential low-cost green processing for the industrial fortification of food products with resveratrol and other health-beneficial antioxidants. © 2019 Society of Chemical Industry.

Fish exposed to water contaminated with eprinomectin show inhibition of the activities of AChE and Na+/K+-ATPase in the brain, and changes in natural behavior

The objective of this study was to evaluate whether antiparasitic eprinomectin may be an environmental contaminant in water compartment in low concentrations, negatively affecting neurotransmission and, consequently, the natural behavior of the jundiá (Rhamdia quelen). Fish were randomly allocated in tanks and exposed for 24 and 48 h to eprinomectin concentrations in water [0.0 (Control), 1.124 (T1), 1.809 (T2) and 3.976 (T3) μg L^-1], followed by 48 h of recovery in eprinomectin-free water, in order to evaluate the behavioral parameters, levels of reactive oxygen species (ROS) in the brain, as well as cerebral enzymatic activities of acetylcholinesterase (AChE) and of the sodium-potassium ATPase pump (Na⁺/K⁺-ATPase). Especially at the two highest concentrations of eprinomectin (T2 and T3), the fish showed alterations in natural behavior, particularly hyperlocomotion and longer time on the surface. Furthermore, at these same concentrations, cerebral ROS levels increased and cerebral AChE activity decreased. At the highest concentration (T3) cerebral Na⁺/K⁺-ATPase activity was reduced. Increased ROS and impairment of AChE and Na⁺/K⁺-ATPase enzymes in the brain may have contributed directly to behavioral changes, due to neuronal damage and synapse impairment. Even after 48 h in water without eprinomectin, behavioral changes and neurotoxic effects were observed in fish, suggesting residual effects of the antiparasitic. In conclusion, eprinomectin even in low concentrations may be a hazardous environmental contaminant for aquatic organisms, as it causes brain damage and affects the natural behavior of fish.

Systematic review: Impact of resveratrol exposure during pregnancy on maternal and fetal outcomes in animal models of human pregnancy complications-Are we ready for the clinic?

Resveratrol (RSV) has been reported to have potential beneficial effects in the complicated pregnancy. Various pregnancy complications lead to a suboptimal in utero environment that impacts fetal growth during critical windows of development. Detrimental structural changes to key organ systems in utero persist into adult life and predispose offspring to an increased risk of chronic non-communicable metabolic diseases such as cardiovascular disease, diabetes and obesity. The aim of this systematic review was to determine the effect of gestational RSV exposure on both maternal and fetal outcomes. Publicly available databases (n = 8) were searched for original studies reporting maternal and/or fetal outcomes after RSV exposure during pregnancy irrespective of species. Of the 115 studies screened, 31 studies were included in this review. RSV exposure occurred for different durations across a range of species (Rats n = 18, Mice n = 7, Japanese Macaques n = 3 and Sheep n = 3), models of complicated pregnancy (eg. maternal dietary manipulations, gestational diabetes, maternal hypoxia, teratogen exposure, etc.), dosages and administration routes. Maternal and fetal outcomes differed not only based on the model of complicated pregnancy assessed but also as a result of species. Given the heterogenic nature of these studies, further investigation assessing RSV exposure during the complicated pregnancy is warranted. In order to make an informed decision regarding the use of RSV to intervene in pregnancy complications, we suggest a minimum data set for consideration in future studies.

Maternal Resveratrol Supplementation Prevents Cognitive Decline in Senescent Mice Offspring

A variety of environmental factors contribute significantly to age-related cognitive decline and memory impairment in Alzheimer’s Disease (AD) and other neurodegenerative diseases. Nutrition can alter epigenetics, improving health outcomes, which can be transmitted across generations; this process is called epigenetic inheritance. We investigate the beneficial effects of maternal resveratrol supplementation in the direct exposed F1 generation and the transgenerational F2 generation. The offspring was generated from females Senescence Accelerated Mouse-Prone (SAMP8) fed a resveratrol-enriched diet for two months prior to mating. Object novel recognition and Morris Water Maze (MWM) demonstrated improvements in cognition in the 6-month-old F1 and F2 generations from resveratrol fed mothers. A significant increase in global DNA methylation with a decrease in hydroxymethylation in F1 and F2 were found. Accordingly, Dnmt3a/b and Tet2 gene expression changed. Methylation levels of Nrf2 and NF-kβ genes promoters raised in offspring, inducing changes in target genes expression, as well as hydrogen peroxide levels. Offspring that resulted from a resveratrol fed mother showed increase AMPKα activation, mTOR inhibition, and an increase in Pgc-1α gene expression and Beclin-1 protein levels. Endoplasmic reticulum stress sensors were found changed both in F1 and F2 generations. Overall, our results demonstrated that maternal resveratrol supplementation could prevent cognitive impairment in the SAMP8 mice offspring through epigenetic changes and cell signaling pathways.

Preventing childhood and lifelong disability: Maternal dietary supplementation for perinatal brain injury

The majority of brain injuries that lead to cerebral palsy, developmental disability, and mental health disorders have their onset in utero. These lifelong conditions come with great economic and emotional burden as they impact function in nearly all domains of affected individuals' lives. Unfortunately, current therapeutic options are limited. There remains a focus on rescue, rehabilitation, and regeneration after the injury has occurred, rather than aiming to prevent the initial injury. Prevention would imply treating the mother during pregnancy to alter the fetal environment and in turn, treat the fetus. Fear of harming the developing fetus remains as a result of errors of the past such as the release of thalidomide. In this review, we outline evidence from animal studies and clinical trials that have explored maternal dietary supplementation with natural health products (including nutraceuticals and functional foods) for perinatal brain injury prevention. Namely, we discuss magnesium sulphate, creatine, choline, melatonin, resveratrol and broccoli sprouts/sulforaphane. Although clinical trials have only been completed in this realm for magnesium sulphate, results in animal models have been promising, suggesting that this is a productive avenue for further research. Natural health products may provide safe, effective, affordable, and easily accessible prevention of fetal brain injury and resulting lifelong disabilities.

Taurine promotes cognitive function in prenatally stressed juvenile rats via activating the Akt-CREB-PGC1α pathway

Substantial evidence has shown that the oxidative damage to hippocampal neurons is associated with the cognitive impairment induced by adverse stimuli during gestation named prenatal stress (PS). Taurine, a conditionally essential amino acid, possesses multiple roles in the brain as a neuromodulator or antioxidant. In this study, to explore the roles of taurine in PS-induced learning and memory impairment, prenatal restraint stress was set up and Morris water maze (MWM) was employed for testing the cognitive function in the one-month-old rat offspring. The mitochondrial reactive oxygen species (ROS) level，mitochondrial membrane potential (MMP), ATP and cytochrome c oxidase (CcO) activity and apoptosis-related proteins in the hippocampus were detected. The activity of the Akt-cyclic AMP response element-binding protein (CREB)-peroxisome proliferator-activated receptor–γ coactivator-1α (PGC1α) pathway in the hippocampus was measured. The results showed that high dosage of taurine administration in the early postnatal period attenuated impairment of spatial learning and memory induced by PS. Meanwhile, taurine administration diminished the increase in mitochondrial ROS, and recovered the reduction of MMP, ATP level and the activities of CcO, superoxide dismutase 2 (SOD2) and catalase induced by PS in the hippocampus. In addition, taurine administration recovered PS-suppressed SOD2 expression level. Taurine administration blocked PS-induced decrease in the ratio of Bcl-2/Bax and increase in the ratio of cleaved caspase-3/full-length caspase-3. Notably, taurine inhibited PS-decreased phosphorylation of Akt (pAkt) and phosphorylation of CREB (pCREB), which consequently enhanced the mRNA and protein levels of PGC1α. Taken together, these results suggest that high dosage of taurine administration during the early postnatal period can significantly improve the cognitive function in prenatally stressed juvenile rats via activating the Akt-CREB-PGC1α pathway. Therefore, taurine has therapeutic potential for prenatal stressed offspring rats in future.

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Taurine attenuates prenatal stress (PS)-induced cognitive impairment.

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Taurine reduces PS-induced neuronal apoptosis and mitochondrial dysfunction.

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Taurine maintains the activities of SOD2 and catalase to repress ROS.

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Taurine activates PS-suppressed Akt-CREB-PGC1α pathway.

Resveratrol: A Potential Hippocampal Plasticity Enhancer

The search for molecules capable of restoring altered hippocampal plasticity in psychiatric and neurological conditions is one of the most important tasks of modern neuroscience. It is well established that neural plasticity, such as the ability of the postnatal hippocampus to continuously generate newly functional neurons throughout life, a process called adult hippocampal neurogenesis (AHN), can be modulated not only by pharmacological agents, physical exercise, and environmental enrichment, but also by “nutraceutical” agents. In this review we focus on resveratrol, a phenol and phytoalexin found in the skin of grapes and red berries, as well as in nuts. Resveratrol has been reported to have antioxidant and antitumor properties, but its effects as a neural plasticity inducer are still debated. The current review examines recent evidence implicating resveratrol in regulating hippocampal neural plasticity and in mitigating the effects of various disorders and diseases on this important brain structure. Overall, findings show that resveratrol can improve cognition and mood and enhance hippocampal plasticity and AHN; however, some studies report opposite effects, with resveratrol inhibiting aspects of AHN. Therefore, further investigation is needed to resolve these controversies before resveratrol can be established as a safe coadjuvant in preventing and treating neuropsychiatric conditions.

Intrahippocampal Administration of Ibotenic Acid Induced Cholinergic Dysfunction via NR2A/NR2B Expression: Implications of Resveratrol against Alzheimer Disease Pathophysiology

Although several drugs revealed moderate amelioration of symptoms, none of them have sufficient potency to prevent or reverse the progression toward Alzheimer's disease (AD) pathology. Resveratrol (RSV), a polyphenolic compound has shown an outstanding therapeutic effect on a broad spectrum of diseases like age-associated neurodegeneration, inflammation etc. The present study was thus conducted to assess the therapeutic efficacy of RSV in ameliorating the deleterious effects of Ibotenic acid (IBO) in male Wistar rats. Stereotactic intrahippocampal administration of IBO (5 μg/μl) lesioned rats impairs cholinergic transmission, learning and memory performance that is rather related to AD and thus chosen as a suitable model to understand the drug efficacy in preventing AD pathophysiology. Since IBO is an agonist of glutamate, it is expected to exhibit an excitotoxic effect by altering glutamatergic receptors like NMDA receptor. The current study displayed significant alterations in the mRNA expression of NR2A and NR2B subunits of NMDA receptors, and further it is surprising to note that cholinergic receptors decreased in expression particularly α7-nAChR with increased m1AChR. RSV administration (20 mg/kg body weight, i.p.) significantly reduced these changes in IBO induced rats. Glutamatergic and cholinergic receptor alterations were associated with significant changes in the behavioral parameters of rats induced by IBO. While RSV improved spatial learning performance, attenuated immobility, and improvised open field activity in IBO induced rats. NR2B activation in the present study might mediate cell death through oxidative stress that form the basis of abnormal behavioral pattern in IBO induced rats. Interestingly, RSV that could efficiently encounter oxidative stress have significantly decreased stress markers viz., nitrite, PCO, and MDA levels by enhancing antioxidant status. Histopathological analysis displayed significant reduction in the hippocampal pyramidal layer thickness and live neurons in IBO induced rats, with slight pathological changes in the entorhinal cortex (EC) of rat brain, which was prevented on RSV administration. Our study thus concludes that RSV administration significantly ameliorated the deleterious effects in the IBO lesioned rat model for AD by alleviating cholinergic pathways, reducing oxidative stress and thereby improving spatial memory.

Resveratrol partially prevents oxidative stress and metabolic dysfunction in pregnant rats fed a low protein diet and their offspring

Protein restriction in pregnancy produces maternal and offspring metabolic dysfunction potentially as a result of oxidative stress. Data are lacking on the effects of inhibition of oxidative stress. We hypothesized that maternal resveratrol administration decreases oxidative stress, preventing, at least partially, maternal low protein-induced maternal and offspring metabolic dysfunction. In the present study, pregnant wistar rats ate control (C) (20% casein) or a protein-restricted (R) (10% casein) isocaloric diet. Half of each group received resveratrol orally, 20 mg kg(-1) day(-1), throughout pregnancy. Post-delivery, mothers and offspring ate C. Oxidative stress biomarkers and anti-oxidant enzymes were measured in placenta, maternal and fetal liver, and maternal serum corticosterone at 19 days of gestation (dG). Maternal (19 dG) and offspring (postnatal day 110) glucose, insulin, triglycerides, cholesterol, fat and leptin were determined. R mothers showed metabolic dysfunction, increased corticosterone and oxidative stress and reduced anti-oxidant enzyme activity vs. C. R placental and fetal liver oxidative stress biomarkers and anti-oxidant enzyme activity increased. R offspring showed higher male and female leptin, insulin and corticosterone, male triglycerides and female fat than C. Resveratrol decreased maternal leptin and improved maternal, fetal and placental oxidative stress markers. R induced offspring insulin and leptin increases were prevented and other R changes were offspring sex-dependent. Resveratrol partially prevents low protein diet-induced maternal, placental and sex-specific offspring oxidative stress and metabolic dysfunction. Oxidative stress is one mechanism programming offspring metabolic outcomes. These studies provide mechanistic evidence to guide human pregnancy interventions when fetal nutrition is impaired by poor maternal nutrition or placental function.

Pretreatment with Resveratrol Prevents Neuronal Injury and Cognitive Deficits Induced by Perinatal Hypoxia-Ischemia in Rats

Despite advances in neonatal care, hypoxic-ischemic brain injury is still a serious clinical problem, which is responsible for many cases of perinatal mortality, cerebral palsy, motor impairment and cognitive deficits. Resveratrol, a natural polyphenol with important anti-oxidant and anti-inflammatory properties, is present in grapevines, peanuts and pomegranates. The aim of the present work was to evaluate the possible neuroprotective effect of resveratrol when administered before or immediately after a hypoxic-ischemic brain event in neonatal rats by analyzing brain damage, the mitochondrial status and long-term cognitive impairment. Our results indicate that pretreatment with resveratrol protects against brain damage, reducing infarct volume, preserving myelination and minimizing the astroglial reactive response. Moreover its neuroprotective effect was found to be long lasting, as behavioral outcomes were significantly improved at adulthood. We speculate that one of the mechanisms for this neuroprotection may be related to the maintenance of the mitochondrial inner membrane integrity and potential, and to the reduction of reactive oxygen species. Curiously, none of these protective features was observed when resveratrol was administered immediately after hypoxia-ischemia.

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.

Possible role of resveratrol targeting estradiol and neprilysin pathways in lipopolysaccharide model of Alzheimer disease

Alzheimer's disease (AD) is an irreversible, progressive neurodegenerative brain disease that slowly destroys memory and thinking skills. It is the most common cause of dementia among older people. One of the most important hallmarks of AD is the presence of amyloid beta (Aβ) peptide in the brain that suggests that it is the primary trigger for neuronal loss. Herbal extracts have been studied over the years for their potential therapeutic effect in AD. Resveratrol (RSV), one of the most important phytoestrogens, is considered to be useful as estrogen plays an important role in AD. One of the most important amyloid degrading enzymes is neprilysin (NEP), which plays a major role in degrading Aβ, and mainly affected by estrogen. So, the aim of the present study is investigating the possible role of resveratrol in lipopolysaccharide model of AD and the implication of its possible role in regulating the estradiol and neprilysin pathways. Mice were divided into four groups: Control group (0.9 % saline), LPS group (0.8 mg/kg i.p once), Treatment group with RSV (mice were once injected with LPS then after 30 min given a dose of {4 mg/kg} RSV for 7 days), and RSV group only (mice received 4 mg/kg i.p for 7 days only). After 7 days mice were subjected to different behavioral tests using Y-maze, object recognition test, and open field tests. Estradiol and NEP level were measured using ELISA kit. Results showed RSV was able to reverse the decline in different types of memory (working, nonspatial, and locomotor functions) caused by LPS induction in mice. Moreover RSV was able to significantly increase both the estradiol level and NEP level and that may have a great role to decrease Aβ deposition as it has been confirmed that there is a link between NEP and estradiol level; by upregulation of estradiol level this consequently leads to increase in the level of NEP level, and by increasing the NEP level in brain, this lead to decrease in Aβ deposition and enhancing its degradation by NEP.

Social deficits induced by peripubertal stress in rats are reversed by resveratrol

Adolescence is increasingly recognized as a critical period for the development of the social system, through the maturation of social competences and of their underlying neural circuitries. The present study sought to test the utility of resveratrol, a dietary phenol recently reported to have mood lifting properties, in modulating social interaction that is deficient following early life adversity. The main aims were to 1) pharmacologically restore normative social investigation levels dampened by peripubertal stress in rats and 2) identify neural pathways engaged by this pharmacological approach. Following peripubertal (P28-42) stress consisting of unpredictable exposures to fearful experiences, at adulthood the subjects' propensity for social exploration was examined in the three-chamber apparatus, comparing time invested in social or non-social investigation. Administered intraperitoneally 30 min before testing, resveratrol (20 mg/kg) normalized the peripubertal stress-induced social investigation deficit seen in the vehicle group, selectively altering juvenile but not object exploration. Examination of prefrontal cortex subregion protein samples following acute resveratrol treatment in a separate cohort revealed that while monoamine oxidase A (MAOA) enzymatic activity remained unaltered, nuclear AKT activation was selectively increased in the infralimbic cortex, but not in the prelimbic or anterior cingulate cortex. In contrast, androgen receptor nuclear localization was increased in the prelimbic cortex, but not in the infralimbic or anterior cingulate cortex. This demonstration that social contact deficits are reversed by resveratrol administration emphasizes a prosocial role for this dietary phenol, and evokes the possibility of developing new treatments for social dysfunctions.

AMPK activation prevents prenatal stress-induced cognitive impairment: modulation of mitochondrial content and oxidative stress

Prenatal stress induces cognitive functional impairment in offspring, an eventuality in which mitochondrial dysfunction and oxidative stress are believed to be closely involved. In this study, the involvement of the AMP-activated protein kinase (AMPK) pathway was investigated. A well-known activator, resveratrol (Res), was used to induce AMPK activation in SH-SY-5Y cells. Significant mitochondrial biogenesis and phase II enzyme activation, accompanied by decreased protein oxidation and GSSG content, were observed after Res treatment, and inhibition of AMPK with Compound c abolished the induction effects of Res. Further study utilizing a prenatal restraint stress (PRS) animal model indicated that maternal supplementation of Res may activate AMPK in the hippocampi of both male and female offspring, and that PRS-induced mitochondrial loss in the offspring hippocampus was inhibited by Res maternal supplementation. In addition, Res activated Nrf2-mediated phase II enzymes and reduced PRS-induced oxidative damage in both male and female offspring. Moreover, PRS markedly decreased mRNA levels of various neuron markers, as well as resultant offspring cognitive function, based on spontaneous alternation performance and Morris water maze tests, the results of which were significantly improved by maternal Res supplementation. Our results provide evidence indicating that AMPK may modulate mitochondrial content and phase II enzymes in neuronal cells, a process which may play an essential role in preventing PRS-induced cognitive impairment. Through the coupling of mitochondrial biogenesis and the Nrf2 pathway, AMPK may modulate oxidative stress and be a promising target against neurological disorders.

Prenatal stress and inhibitory neuron systems: implications for neuropsychiatric disorders

Prenatal stress is a risk factor for several psychiatric disorders in which inhibitory neuron pathology is implicated. A growing body of research demonstrates that inhibitory circuitry in the brain is directly and persistently affected by prenatal stress. This review synthesizes research that explores how this early developmental risk factor impacts inhibitory neurons and how these findings intersect with research on risk factors and inhibitory neuron pathophysiology in schizophrenia, anxiety, autism and Tourette syndrome. The specific impact of prenatal stress on inhibitory neurons, particularly developmental mechanisms, may elucidate further the pathophysiology of these disorders.

Resveratrol: review on therapeutic potential and recent advances in drug delivery

INTRODUCTION

Natural products have seen a wide range of acceptability for the prevention and treatment of diseases throughout history. Resveratrol, a member of the stilbene family, has been found to potentially exhibit anticancer, antiangiogenic, immunomodulatory and cardioprotective activities as well as being an antioxidant. This is in addition to its usefulness in the treatment of neurodegenerative disease, diabetes and cardiac ailments. Currently, various studies have revealed that resveratrol is a potential drug candidate with multi-spectrum therapeutic application.

AREAS COVERED

This review aims to describe the various studies supporting the wide range of pharmacological activities of resveratrol. In addition, it includes a section devoted to discussing the challenges associated with the drug and strategies to improve the properties of resveratrol such as solubility, stability and bioavailability.

EXPERT OPINION

Resveratrol demonstrated its ability to be a potential drug candidate for the treatment of different ailments due to its potent antioxidant properties. To improve the drug stability, increase the bioavailability and minimize side-effects of resveratrol, novel drug delivery systems have been formulated to bring this potential candidate to the first line of disease treatment.

Resveratrol improves postnatal hippocampal neurogenesis and brain derived neurotrophic factor in prenatally stressed rats

Prenatal stress induced neuronal dysfunction is multifactorial, including suppressed neurogenesis in developing brain. Resveratrol is known to exert its neuroprotective potential by enhancing neurogenesis. But the efficacy of resveratrol against prenatal stress was not addressed in detail. Hence in the present study we evaluated the neuroprotective action of resveratrol on prenatal stress-induced impaired neurogenesis. Pregnant rats were subjected to restraint stress during early or late gestational period. Another sets of rats received resveratrol during entire gestational period along with early or late gestational stress. The study parameters included neuronal assay of doublecortin positive neurons (DCX +ve) and brain derived neurotrophic factor (BDNF) estimations in 40th postnatal day rat brain. Both early and late gestational stress resulted in significant decrease in generation of new born neurons and BDNF expression in hippocampus. The decrease in number of DCX +ve neurons and hippocampal BDNF expression was more profound in the offspring who received late gestational stress compared to early gestational stress. Resveratrol treatment has improved the expression of DCX +ve neurons and BDNF expression. These data suggest the neuroprotective efficacy of resveratrol against prenatal stress induced impaired neurogenesis.

Biotransformation of polydatin to resveratrol in Polygonum cuspidatum roots by highly immobilized edible Aspergillus niger and Yeast

A new biotransformation method of producing resveratrol with co-immobilized edible Aspergillus niger and Yeast (AY) was investigated. The biotransformation conditions were optimized for the resveratrol production under 30 °C, pH 6.5, 2 days, liquid-solid ratio 12:1 (mL/g), the yield of resveratrol reached 33.45 mg/g, which increased 11-fold to that of untreated one. The conversion rate of polydatin reached 96.7%. The residual activity of immobilized microorganism was 83.2% after used for 15 runs. The developed method could be an effectively alternative biotransformation method for producing resveratrol from the plants.