Resveratrol pretreatment attenuates the isoflurane-induced cognitive impairment through its anti-inflammation and -apoptosis actions in aged mice

Effects and safety of resveratrol supplementation in older adults: A comprehensive systematic review

Resveratrol (RSV) has garnered significant attention in recent years due to its potential benefits against chronic diseases. However, its effects and safety in older adults have not been comprehensively studied. This study aimed to determine the effects and safety of RSV supplementation in older adults. MEDLINE/PubMed, Scopus, and Web of Science databases were comprehensively searched for eligible studies. Studies were enrolled if they were randomized clinical trials and had incorporated RSV supplementation for older adults. Two independent authors conducted the literature search, and eligibility was determined according to the PICOS framework. Study details, intervention specifics, and relevant outcomes were collected during the data collection. The Cochrane RoB-2 tool was used to evaluate the risk of bias. This review included 10 studies. The combination of RSV and exercise improved exercise adaptation and muscle function in healthy older adults and physical performance and mobility measures in individuals with functional limitations. RSV showed potential neuroprotective effects in patients with Alzheimer's disease. In overweight individuals, RSV demonstrated a positive impact on cognitive function, but it increased some biomarkers of cardiovascular disease risk at high doses. In older adults with diabetes and those with peripheral artery disease (PAD), RSV was not more effective than placebo. No study reported significant adverse events following RSV treatment. RSV can improve various health parameters in age-related health conditions. However, the optimal dosage, long-term effects, and potential interactions with medications still need to be investigated through well-designed RCTs.

Latest advances and clinical application prospects of resveratrol therapy for neurocognitive disorders

Neurocognitive disorders, such as Alzheimer's disease, vascular dementia, and postoperative cognitive dysfunction, are non-psychiatric brain syndromes in which a significant decline in cognitive function causes great trauma to the mental status of the patient. The lack of effective treatments for neurocognitive disorders imposes a considerable burden on society, including a substantial economic impact. Over the past few decades, the identification of resveratrol, a natural plant compound, has provided researchers with an opportunity to formulate novel strategies for the treatment of neurocognitive disorders. This is because resveratrol effectively protects the brain of those with neurocognitive disorders by targeting some mechanisms such as inflammation and oxidative stress. This article reviews the status of recent research investigating the use of resveratrol for the treatment of different neurocognitive disorders. By examining the possible mechanisms of action of resveratrol and the shared mechanisms of different neurocognitive disorders, treatments for neurocognitive disorders may be further clarified.

Resveratrol prevents cognitive deficits induced by sleep deprivation via modulating sirtuin 1 associated pathways in the hippocampus

Accumulating evidence confirms that sleep insufficiency is a high risk factor for cognitive impairment, which involves inflammation and synaptic dysfunction. Resveratrol, an agonist of the Sirt1, has demonstrated anti-inflammation and neuroprotective effects in models of Alzheimer's disease, Parkinson's disease, and schizophrenia. However, the beneficial effects of resveratrol on sleep deprivation-induced cognitive deficits and its underlying molecular mechanisms are unclear. In the present study, thirty-two male C57BL/6 J mice were randomly divided into a Control+DMSO group, Control+Resveratrol group, SD+DMSO group, and SD+Resveratrol group. The mice in the SD+Resveratrol group underwent 5 days of sleep deprivation after pretreatment with resveratrol (50 mg/kg) for 2 weeks, while the mice in the SD+DMSO group only underwent sleep deprivation. After sleep deprivation, we evaluated spatial learning and memory function using the Morris water maze test. We used general molecular biology techniques to detect changes in levels of pro-inflammatory cytokines and Sirt1/miR-134 pathway-related synaptic plasticity proteins. We found that resveratrol significantly reversed sleep deprivation-induced learning and memory impairment, elevated interleukin-1β, interleukin-6, and tumor necrosis factor-α levels, and decreased brain-derived neurotrophic factor, tyrosine kinase receptor B, postsynaptic density protein-95, and synaptophysin levels by activating the Sirt1/miR-134 pathway. In conclusion, resveratrol is a promising agent for preventing sleep deprivation-induced cognitive dysfunction by reducing pro-inflammatory cytokines and improving synaptic function via the Sirt1/miR-134 pathway.

ANGPTL2 Deletion Attenuates Neuroinflammation and Cognitive Dysfunction Induced by Isoflurane in Aged Mice through Modulating MAPK Pathway

Postoperative cognitive dysfunction (POCD) is a well-known complication after surgery with cognitive impairments. Angiopoietin-like protein 2 (ANGPTL2) has been found to be associated with inflammation. However, the role of ANGPTL2 in inflammation of POCD is unclear. Here, mice were subjected into isoflurane anesthesia. It was demonstrated that isoflurane increased ANGPTL2 expression and promoted pathological change in brain tissues. However, downregulation of ANGPTL2 alleviated the pathological change and elevated learning and memory abilities, improving isoflurane-induced cognitive dysfunction in mice. In addition, isoflurane-induced cell apoptosis and inflammation were repressed via ANGPTL2 knockdown in mice. Downregulation of ANGPTL2 was also verified to suppress isoflurane-induced microglial activation, evidenced by a decrease of Iba1 and CD86 expressions and an increase of CD206 expression. Further, the isoflurane-induced MAPK signaling pathway was repressed through downregulation of ANGPTL2 in mice. In conclusion, this study proved that downregulation of ANGPTL2 attenuated isoflurane-induced neuroinflammation and cognitive dysfunction in mice via modulating the MAPK pathway, which provided a new therapeutic target for POCD.

The antioxidant properties of resveratrol on sperm parameters, testicular tissue, antioxidant capacity, and lipid peroxidation in isoflurane-induced toxicity in mice

This study explores whether resveratrol effectively protects the reproductive system against isoflurane-induced toxicity in testicular tissue. In this experiment, we randomly divided 60 adult male C57BL/6 mice into six groups (n = 10). Five consecutive days per week, mice were exposed to 1.5% isoflurane for 1 h/day and were given 50 and 100 mg/kg resveratrol. After 35 days (the completion of the mouse spermatogenesis period), the left testis was removed for histomorphometric evaluations, while the right testis was used to determine the Capacity of total antioxidants and lipid peroxidation. To analyze the Parameters of sperm, chromatin maturation, and DNA fragmentation, the left caudal epididymis was used. Based on a one-way analysis of variance (ANOVA), we considered a difference in means of 0.05 to be significant (P0.05). Compared to the control group, the isoflurane group showed a significant decrease in testicular weight, volume, sperm parameters, and tissue histomorphometry. Comparatively, to the control group, malondialdehyde levels increased, and the total antioxidant capacity decreased significantly. Resveratrol improved all of the above parameters in the simultaneous treatment groups compared to the isoflurane group. It did not, however, reach the level of the control group in all cases. It has been demonstrated that resveratrol, with its powerful antioxidant properties, reduces the reproductive toxicity of isoflurane by inhibiting free radicals and increasing the testicular tissue's antioxidant capacity.

Dexmedetomidine suppresses the isoflurane-induced neurological damage by upregulating Heme Oxygenase-1 via activation of the mitogen-activated protein kinase kinase 1/extracellular regulated protein kinases 1/nuclear factor erythroid 2-related factor 2 axis in aged rats

Dexmedetomidine (DEX) displays a neuroprotective role in aged rats with isoflurane (ISO)-induced cognitive impairment through antioxidant, and anti-inflammatory, and anti-apoptotic effects. Therefore, the present study was performed to define the molecular mechanism of DEX on ISO-induced neurological impairment in aged rats in relation to the MEK1/ERK1/Nrf2/HO-1 axis. The study enrolled elderly patients undergoing ISO anesthesia. Patient cognitive function following treatment with DEX was evaluated using mini-mental state examination (MMSE). The results revealed that DEX supplementation of anesthesia contributed to higher MMSE scores in patients one week post treatment. Rat model of neurological impairment was also induced in 18-month-age Wistar rats by ISO, followed by DEX treatment. Based on the results of Morris water maze experiment, ELISA, and TUNEL and hematoxylin-eosin staining, in vivo experiments confirmed that DEX could reduce the oxidative stress and neurological damage induced by ISO in rats. DEX activated the nuclear factor erythroid 2-related factor (Nrf2)/Heme Oxygenase 1 (HO-1) pathway. DEX upregulated the expression of Nrf2 and HO-1 by activating the MEK1/ERK1 pathway, whereby attenuating the ISO-caused oxidative stress and neurological damage in rats. Collectively, DEX suppresses the ISO-induced neurological impairment in the aged rats by promoting HO-1 through activation of the MEK1/ERK1/Nrf2 axis.

Protective effects of chlorogenic acid on isoflurane‐induced cognitive impairment of aged mice

Postoperative cognitive dysfunction (POCD) is characterized by impairment in cognitive functions in patients following anesthesia and surgery. Chlorogenic acid (CGA) is a plant‐derived compound possessing numerous bioactive properties. The aim of this study was to investigate the therapeutic potential of CGA in isoflurane (ISO)‐induced cognitive dysfunction of aged mice, and further identify the mechanisms involved in the protective effects of CGA. A total of 80 male C57BL/6 mice, 20‐month‐old, were randomly divided into control group, isoflurane group (ISO), and ISO + 30 mg/kg CGA group and ISO + 60 mg/kg CGA. CGA was given orally once daily for 7 days to the mice and they were exposed to ISO (1.5%; 4 h). The open‐field and Morris water maze tests were used to investigate the cognitive function of mice. Pretreatment with CGA significantly attenuated ISO‐induced cognitive impairment. The levels of IL‐1β, TNF‐α, IL‐6, nuclear p65 NF‐kB, cleaved caspase‐3, and Bax were significantly increased, while the levels of IkBα and Bcl‐2 were decreased in the hippocampus 24 h after the ISO anesthesia. All the mentioned effects induced by ISO were reversed by CGA pretreatment. Furthermore, ISO exposure induced marked downregulation of SOD, CAT, HO‐1, and NQO‐1 and elevation of MDA and nuclear translocation of Nrf2 in the hippocampus tissue. All these parameters were reversed by CGA treatment. Importantly, the higher dose of CGA (60 mg/kg) showed a greater neuroprotective effect. In conclusion, these findings suggest that CGA attenuates the ISO‐induced cognitive impairment via its anti‐inflammatory, anti‐oxidative, and anti‐apoptotic properties in aged mice.

Does Resveratrol Prevent Sevoflurane Toxicity in Newborn Rats?

Inhalation anesthetics have been shown to cause neurodevelopmental disorders and neurotoxic effects. In this study, we aimed to investigate the effect of resveratrol on the possible neurotoxic effect of sevoflurane and the brain-derived neurotrophic factor (BDNF) pathway in newborn rats. The animals were divided into four groups: control, sevoflurane, sevoflurane+resveratrol 25 mg/kg, and sevoflurane+resveratrol 50 mg/kg. The groups that received anesthesia were given 3% sevoflurane for 2 h on the postnatal seventh, eighth, and ninth days. Control gas was applied to the control group. The Morris water maze (MWM) test was performed on postnatal 35th day. After performing the open field test on the postnatal 41st day, the animals were dissected, and the hippocampal BDNF levels were determined by Western blot method. In the MWM test, there was a significant decrease in the time spent in the target quadrant in the sevoflurane anesthesia group compared with control group. This reduction was reversed with the resveratrol pretreatment. Sevoflurane exposure significantly decreased hippocampal BDNF levels compared with the control group. The resveratrol 25 mg/kg pretreatment did not reverse this reduction, whereas resveratrol 50 mg/kg ameliorated this impairment. Sevoflurane did not cause any significant difference in the rats' performance in the open field test. However, 50 mg/kg resveratrol pretreatment caused a statistically significant increase in this performance. Our results showed that sevoflurane impaired learning and memory functions in newborn rats and resveratrol reversed this deterioration. Also BDNF might play a role in this beneficial effect of resveratrol.

Neuroprotective effect of AGGF1 against isoflurane-induced cognitive dysfunction in aged rats through activating the PI3K/AKT signaling pathways

PURPOSE

This study aimed to evaluate and identify the value and explore the mechanisms of Angiogenic Factor with G-patch and FHA domains 1 (AGGF1) in postoperative cognitive dysfunction (POCD).

METHODS

Rats were separated into four different groups, namely sham, isoflurane, isoflurane + recombinant human Aggf1 (rh-Aggf1) (5 μg kg-1), and isoflurane + rh-Aggf1 (10 μg kg-1). qPCR and western blot assays were applied to detect the correlation between the expression of AGGF1 and isoflurane administration. Then, the Morris water maze (MWM) test was applied to evaluate the effect of AGGF1 on improving the POCD rats. Subsequently, TUNEL assay was applied and the cell apoptosis-related proteins were tested to reveal the anti-apoptotic effect of AGGF1 in POCD rats. Furthermore, the mRNA and protein levels of TNF-α, IL-6, and IL-1β were also detected by qPCR and ELISA to verify the anti-inflammatory effects of AGGF1 on POCD rats. Besides, the protein expression levels of PI3K, Akt, and NF-κB in each group were examined by western blot.

RESULTS

In this study, the results revealed that isoflurane induced a decrease in AGGF1 expression in the hippocampus of aged rats. In addition, exogenous AGGF1 attenuated POCD in aged rats. Meanwhile, exogenous AGGF1 had anti-apoptotic and anti-inflammatory effects in POCD rats. Further research indicated that AGGF1 activated the PI3K/Akt pathway.

CONCLUSION

AGGF1 has neuroprotective effect against isoflurane-induced cognitive dysfunction in aged rats via activating the PI3K/AKT signaling pathways.

Resveratrol Inhibits NLRP3 Inflammasome-Induced Pyroptosis and miR-155 Expression in Microglia Through Sirt1/AMPK Pathway

Resveratrol is a natural polyphenolic compound with a wide range of biological activities such as antioxidant, anti-carcinogenic, anti-obesity, anti-aging, anti-inflammatory, immunomodulatory properties. Accumulating evidence suggests that resveratrol has pharmacological benefits in life-threatening diseases, including cardiovascular disease, cancer, diabetes, and neurodegenerative diseases. Resveratrol is widely known for its anti-inflammatory properties; however, signaling mechanisms of anti-inflammatory action are still elusive. Studies have illustrated that resveratrol can control different regulatory pathways by altering the expression and consequently regulatory effects of microRNAs. Our study aims to clarify the regulatory mechanisms of resveratrol in its anti-inflammatory features in the N9 microglial cell line. Our results demonstrated that resveratrol inhibits LPS- and ATP-activated NLRP3 inflammasome and protects microglial cells upon oxidative stress, proinflammatory cytokine production, and pyroptotic cell death resulting from inflammasome activation. Additionally, resveratrol inhibits nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling and activates AMPK/Sirt1 pathways. Furthermore, our results indicated that resveratrol downregulated inflammasome-induced miR-155 expression. Then, inhibition of AMPK and Sirt1 pathways has significantly reversed protective effect of resveratrol on miR-155 expression. To sum up, our results suggest that resveratrol suppresses the NLRP3 inflammasome and miR-155 expression through AMPK and Sirt1 pathways in microglia.

Therapeutic Effects of Resveratrol on Ischemia-Reperfusion Injury in the Nervous System

Resveratrol is a phenol compound produced by some plants in response to pathogens, infection, or physical injury. It is well-known that resveratrol has antioxidant and protective roles in damages potentially caused by cancer or other serious disorders. Thus, it is considered as a candidate agent for the prevention and treatment of human diseases. Evidence has confirmed other bioactive impacts of resveratrol, including cardioprotective, anti-tumorigenic, anti-inflammatory, phytoestrogenic, and neuroprotective effects. Ischemia-reperfusion (IR) can result in various disorders, comprising myocardial infarction, stroke, and peripheral vascular disease, which may continue to induce debilitating conditions and even mortality. In virtue of chronic ischemia or hypoxia, cells switch to anaerobic metabolism, giving rise to some dysfunctions in mitochondria. As the result of lactate accumulation, adenosine triphosphate levels and pH decline in cells. This condition leads cells to apoptosis, necrosis, and autophagy. However, restoring oxygen level upon reperfusion after ischemia by producing reactive oxygen species is an outcome of mitochondrial dysfunction. Considering the neuroprotective effect of resveratrol and neuronal injury that comes from IR, we focused on the mechanism(s) involved in IR injury in the nervous system and also on the functions of resveratrol in the protection, inhibition, and treatment of this injury.

Resveratrol Relieves Hyperoxia-Induced Brain Injury in Neonatal Rats by Activating Sirt1

OBJECTIVE

Neonatal rats with hyperoxia-induced brain injury were treated with resveratrol to investigate its protective effects through analyzing changes in reactive oxygen species (ROS), Sirt1, p53, and acetylated p53 levels.

STUDY DESIGN

Neonatal rats were randomly divided into hyperoxia and resveratrol intervened groups. Rats in both groups were placed in a hyperoxia chamber for 7 days to induce hyperoxia-induced brain injury. The rats in the resveratrol intervened group were administered resveratrol 60 μg/g body weight daily, whereas those in the hyperoxia group were administered a dimethyl sulfoxide-based solvent. Brain tissues were collected, and hematoxylin and eosin (H&E) and TUNEL staining, ROS measurements, real time-polymerase chain reaction, and western blotting were performed.

RESULTS

H&E and TUNEL staining revealed increased cell damage and apoptosis in brain tissue from hyperoxia-exposed animals compared with the findings in animals in the resveratrol intervened group. Real time-polymerase chain reaction and western blotting identified increases in Sirt1 expression and decreases in p53 expression in the resveratrol intervened group. In addition, acetylated p53 protein expression was lower in the intervened group than in the hyperoxia group.

CONCLUSION

Resveratrol alleviated brain apoptosis induced by hyperoxia in neonatal rats by upregulating Sirt1-mediated pathways, suggesting its potentially beneficial role in the treatment of brain injury induced by hyperoxia.

Effects and Mechanisms of Resveratrol on Aging and Age-Related Diseases

The aging of population has become an issue of great concern because of its rapid increase. Aging is an important risk factor of many chronic diseases. Resveratrol could be found in many foods, such as grapes, red wine, peanuts, and blueberries. Many studies reported that resveratrol possessed various bioactivities, such as antioxidant, anti-inflammatory, cardiovascular protection, anticancer, antidiabetes mellitus, antiobesity, neuroprotection, and antiaging effects. The antiaging mechanisms of resveratrol were mainly ameliorating oxidative stress, relieving inflammatory reaction, improving mitochondrial function, and regulating apoptosis. Resveratrol could be an effective and safe compound for the prevention and treatment of aging and age-related diseases. In this review, we summarize the effects of resveratrol on aging, life extension, and several age-related diseases, with special attention paid to the mechanisms of antiaging action.

Resveratrol reverses hippocampal synaptic markers injury and SIRT1 inhibition against developmental Pb exposure

Lead (Pb) exposure damages synaptic structural plasticity that results in cognitive impairment. Resveratrol, a natural polyphenolic compound, is one of the most potent agonists of silencing information regulator 1 (SIRT1) discovered to date. However, the effects of SIRT1 on synaptic functional plasticity in early life Pb exposure are not well studied. Herein, the purpose of this study is to investigate the expression of synaptic markers and SIRT1 in rats exposed to Pb and to evaluate the regulatory effect of resveratrol during this process. The Pb exposed male SD pups were treated with resveratrol (50 mg/kg/d) or EDTA (150 mg/kg/d) followed by hippocampal and blood sampling for analysis at postnatal day 21 (PND21). In the Morrris water maze test, resveratrol treatement protected the rats against Pb-induced impairment of learning and memory (P < 0.05). Resveratrol also enhanced the expression of brain-derived neurotrophic factor (BDNF, P < 0.001 vs 0.2% Pb group), and reversed the effects of Pb exposure on SIRT1(P < 0.001 vs 0.2% Pb group). The DG, CA1 and CA3 regions of the hippocampus showed a considerable increase in the expression of pre- and postsynaptic proteins (P < 0.001 vs 0.2% Pb group). In conclusion, our study demonstrated that resveratrol, through the activation of SIRT1, played a protective role against Pb-induced defects in synaptic plasticity, and suggested a new potential adjuvant treatment for Pb poisoning.

Long-term administration of resveratrol at low doses improves neurocognitive performance as well as cerebral blood flow and modulates the inflammatory pathways in the brain

There is an increasing prevalence of coincident cerebrovascular deficiency and cognitive dysfunction with aging. Increased oxidative stress as well as inflammation that occurs with aging are associated with the impairment of cerebral vascularization. Interestingly, Resveratrol (RSV), a natural phytoalexin, is known to be a strong antioxidant and possesses anti-inflammatory properties. Collectively, these observations strongly suggest that RSV could protect against cerebral vascularization defect and then improves the decline cognitive function associated with aging. In order to test this hypothesis, we investigated the effect of a long-term RSV treatment (1.25 mg/day for 5 months) on cognitive performances of animals that we have allowed to age normally. Then, we further analyzed the gene expression profile and the cerebral blood flow in the brain. By means of novel object recognition (NOR) test, we observed that RSV enhanced NOR performances of aged rats. In addition, RSV enhanced cerebral blood flow during NOR task in aged rats. Using microarrays experiments, we also showed that several pathways related to inflammation and oxidative stress (Eicosanoid signaling, MIF-mediated innate immunity, NF-kB signaling, TNFR2 signaling, IL6 signaling, Production of nitric oxide and ROS) were down-regulated in the brain of RSV treatments rats compared to control rats. In conclusion, these results support that a long-term treatment with RSV improves cognitive performance in the elderly male rat model. This effect is associated with an increase in cerebral blood flow and a decrease in the expression of several pro-inflammatory pathways in the brain.

Resveratrol Improves Mitochondrial Biogenesis Function and Activates PGC-1α Pathway in a Preclinical Model of Early Brain Injury Following Subarachnoid Hemorrhage

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) has been shown to play a pivotal role in the regulation of mitochondrial biogenesis in diseases. Resveratrol (RSV), a natural polyphenolic reagent, has powerful antioxidant properties and the ability to scavenge mitochondrial reactive oxygen species (ROS) in a variety of central nervous system diseases. However, the underlying molecular mechanisms of RSV on mitochondrial biogenesis in early brain injury (EBI) following subarachnoid hemorrhage (SAH) remain poorly understood. This study aimed to explore the potential neuroprotective effects of RSV on mitochondrial biogenesis and function by activation of the PGC-1α signaling pathway in a prechiasmatic cistern SAH model. PGC-1α expression and related mitochondrial biogenesis were detected. Amounts of nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM) were determined to evaluate the extent of mitochondrial biogenesis. Increased PGC-1α and mitochondrial biogenesis after SAH were observed in the temporal cortex. Resveratrol increased the expression of PGC-1α, NRF1, and TFAM, and promoted PGC-1α nuclear translocation. Moreover, RSV could scavenge excess ROS, increase the activity of superoxide dismutase (SOD), enhance the potential of mitochondrial membrane and ATP levels, reduce the number of mitochondrial DNA copy, and decrease the level of malondialdehyde (MDA). RSV significantly ameliorated the release of apoptosis-related cytokines, namely P53, cleaved caspase-3, cytochrome c, and BAX, leading to the amelioration of neuronal apoptosis, brain edema, and neurological impairment 24 h after SAH. These results indicate that resveratrol promotes mitochondrial biogenesis and function by activation of the PGC-1α signaling pathway in EBI following SAH.

Sericin modulates learning and memory behaviors by tuning of antioxidant, inflammatory, and apoptotic markers in the hippocampus of aged mice

Sericin is a protein derived from silkworm cocoons and identified as an anti-aging agent. This study aimed to examine the effects of sericin administration on episodic and avoidance memories, social interaction behavior, and molecular mechanisms including oxidative stress, inflammation, and apoptosis in the hippocampus of aged mice. Sericin was administered at 250 mg/kg/day (oral gavage) to 2-year-old BALB/c mice for a duration of 21 consecutive days. Lashley III Maze and Shuttle-Box tests were performed to assess episodic and avoidance memories, respectively. Subjects also underwent social interaction test to reveal any changes in their social behavior. Besides, markers of oxidative stress (TAC, SOD, GPx, and MDA) and neuroinflammation mediators (TNF-α, IL-1β, and IL-10) were measured in the hippocampus. The extent of apoptosis in the hippocampal tissue was further determined by TUNEL assay and histological assessment. The obtained results suggest that sericin promotes episodic and avoidance memories and social behaviors in aged mice. As of the molecular assay outcomes, it was noted that sericin regulates hippocampal inflammation by inhibiting the pro-inflammatory cytokines, TNF-α and IL-1β, and by increasing the anti-inflammatory factor IL-10. Moreover, sericin suppressed oxidative stress by enhancing antioxidant markers (TAC, SOD, and GPx) and inhibiting MDA. It was also identified that sericin can substantially suppress the apoptosis in the hippocampal tissue. Overall, sericin modulates memory and sociability behavior by tuning hippocampal antioxidant, inflammatory, and apoptotic markers in the aged mice.

Resveratrol ameliorates sevoflurane-induced cognitive impairment by activating the SIRT1/NF-κB pathway in neonatal mice

Sevoflurane, the most commonly used inhaled anesthetic in pediatric anesthesia, has been reported to induce cognitive impairment in developing brain in preclinical and clinical settings. However, the mechanism and therapeutic measures of this developmental neurotoxicity need to be further investigated. Resveratrol, a natural polyphenolic agent, has been reported to improve cognitive function in neurological disorders and aging models through anti-inflammatory activity. However, its effect on sevoflurane-induced cognitive impairment in developing mice remains unknown. The present study was designed to investigate the therapeutic potential of resveratrol on sevoflurane-induced cognitive impairment. Six-day-old mice received anesthesia with 3% sevoflurane 2 h daily on postnatal days (P) 6, P7 and P8. About 100 mg/kg resveratrol were intraperitoneally administered for 6 consecutive days to neonatal mice before anesthesia. Sevoflurane exposure significantly suppressed the expression of Sirtuin 1 (SIRT1) and activated microglia in hippocampi. Furthermore, the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were markedly increased after sevoflurane exposure. Strikingly, resveratrol pretreatment ameliorated sevoflurane-induced SIRT1 inhibition and microglial activation. Of note, resveratrol reversed sevoflurane-induced imbalance of M1/M2 microglia ratio revealed by increasing mRNA level of clusters of differentiation 206 (CD206) and decreasing mRNA levels of clusters of differentiation 86 (CD86) and suppressor of cytokine signaling 3 (SOCS3). Consequently, sevoflurane-induced cognitive impairment in developing mice was ameliorated by resveratrol pretreatment. Taken together, repeated sevoflurane exposure to the developing brain resulted in SIRT1 inhibition, NF-κB acetylation, and microglial activation. Resveratrol pretreatment ameliorated cognitive impairment in developing mice received sevoflurane exposure by modulating SIRT1-NF-κB pathway in microglia. In this regard, our findings open novel directions to explore promising therapeutic targets for preventing the developmental neurotoxicity of sevoflurane.

Association between TNFA, IL10 and IL18 promoter gene variants and cognitive functions in patients with relapsing-remitting multiple sclerosis

OBJECTIVES

To investigate the relationship between TNFA-308G > A, IL10-1082A > G, IL18-607C > A, and cognitive functioning in relapsing-remitting multiple sclerosis (RRMS).

RESULTS

In the patients' group: AG genotype of TNFA-308G > A was associated with higher serum tumor necrosis factor-alpha (TNF-alpha) than GG genotype, and higher TNF-alpha levels correlated with poorer results on Symbol Digit Modalities Test; CC genotype of IL18-607C > A was related to lower score on Isaacs test, compared to AC variant; AA genotype of IL10-1082A > G was associated with abnormally low results on Paced Auditory Series Addition Test.

CONCLUSIONS

TNFA-308G > A, IL10-1082A > G and IL18-607C > A gene variants may be associated with impaired cognitive functions in RRMS patients.

The Beneficial Roles of SIRT1 in Neuroinflammation-Related Diseases

Sirtuins are the class III of histone deacetylases whose deacetylate of histones is dependent on nicotinamide adenine dinucleotide (NAD+). Among seven sirtuins, SIRT1 plays a critical role in modulating a wide range of physiological processes, including apoptosis, DNA repair, inflammatory response, metabolism, cancer, and stress. Neuroinflammation is associated with many neurological diseases, including ischemic stroke, bacterial infections, traumatic brain injury, Alzheimer's disease (AD), and Parkinson's disease (PD). Recently, numerous studies indicate the protective effects of SIRT1 in neuroinflammation-related diseases. Here, we review the latest progress regarding the anti-inflammatory and neuroprotective effects of SIRT1. First, we introduce the structure, catalytic mechanism, and functions of SIRT1. Next, we discuss the molecular mechanisms of SIRT1 in the regulation of neuroinflammation. Finally, we analyze the mechanisms and effects of SIRT1 in several common neuroinflammation-associated diseases, such as cerebral ischemia, traumatic brain injury, spinal cord injury, AD, and PD. Taken together, this information implies that SIRT1 may serve as a promising therapeutic target for the treatment of neuroinflammation-associated disorders.

Role of resveratrol in protecting vasodilatation function in septic shock rats and its mechanism

BACKGROUND

Vascular dysfunction is a major cause of sepsis-induced multiple-organ dysfunction. Resveratrol is a polyphenol compound with extensive pharmacological effects including anti-inflammation. The aim of this study was to determine the role and mechanism of resveratrol in protecting vascular function following sepsis.

METHODS

The cecal ligation and puncture method was used to establish a septic shock rat model. Resveratrol (5 mg/kg and 10 mg/kg) was administered intravenously immediately and at 12 hours after cecal ligation and puncture, respectively. The effects of resveratrol on vasodilatation function, blood flow velocity, hemodynamics, and vital organ function and its relationship to Rac-1 and HIF-1α were observed.

RESULTS

Vascular relaxation reactivity and blood flow velocity were significantly decreased after septic shock, both were significantly improved by resveratrol 5 mg/kg and 10 mg/kg, and the effect of 10 mg/kg was greater. The relaxation reactivity of the superior mesenteric artery to acetylcholine (Ach) was increased by 43.2%. The blood flow velocity of mesenteric arterioles and venules was increased by 47.1% and 51%, respectively, after resveratrol (10 mg/kg) administration compared with the septic shock group. The hemodynamics and both liver and kidney blood flow were significantly decreased after septic shock, which were significantly improved them by resveratrol, which enhanced the vascular relaxation reactivity in septic shock rats. The 72-hour survival rate of septic shock rats in the resveratrol group (62.5%) was significantly higher than that in the septic shock group (6.3%). Resveratrol significantly upregulated the expression of endothelial nitric oxide synthase (eNOS) and downregulated the expression of inducible NOS, Rac-1, and HIF-1α. Inhibitors of Rac-1 and HIF-1α significantly improved the expression of eNOS, and inhibition of eNOS (L-NAME, 5 mg/kg) antagonized the resveratrol-induced improvement in vascular relaxation reactivity and survival.

CONCLUSION

Resveratrol was beneficial for vasodilatation function in rats with septic shock, which is the major contribution to resveratrol improving hemodynamics and organ perfusion. The mechanism involved resveratrol upregulating the expression of eNOS by inhibiting Rac-1 and HIF-1α.

Acetate attenuates perioperative neurocognitive disorders in aged mice

Perioperative neurocognitive disorders are common in elderly patients who have undergone surgical procedures. Neuroinflammation induced by microglial activation is a hallmark of these neurological disorders. Acetate can suppress inflammation in the context of inflammatory diseases. We employed an exploratory laparotomy model with isoflurane anesthesia to study the effects of acetate on perioperative neurocognitive disorders in aged mice. Neurocognitive function was assessed with open-field tests and Morris water maze tests 3 or 7 days post-surgery. Acetate ameliorated the surgery-induced cognitive deficits of aged mice and inhibited the activation of IBA-1, a marker of microglial activity. Acetate also reduced expression of inflammatory proteins (tumor necrosis factor-α, interleukin-1β and interleukin-6), oxidative stress factors (NADPH oxidase 2, inducible nitric oxide synthase and reactive oxygen species), and signaling molecules (nuclear factor kappa B and mitogen-activated protein kinase) in the hippocampus. BV2 microglial cells were used to verify the anti-inflammatory effects of acetate in vitro. Acetate suppressed inflammation in lipopolysaccharide-treated BV2 microglial cells, but not when GPR43 was silenced. These results suggest that acetate may bind to GPR43, thereby inhibiting microglial activity, suppressing neuroinflammation, and preventing memory deficits. This makes acetate is a promising therapeutic for surgery-induced neurocognitive disorders and neuroinflammation.

Resveratrol Mitigates Sevoflurane-Induced Neurotoxicity by the SIRT1-Dependent Regulation of BDNF Expression in Developing Mice

Various lines of evidence suggest that neonatal exposure to general anesthetics, especially repeatedly, results in neuropathological brain changes and long-term cognitive impairment. Although progress has been made in experimental models, the exact mechanism of GA-induced neurotoxicity in the developing brain remains to be clarified. Sirtuin 1 (SIRT1) plays an important role in synaptic plasticity and cognitive performance, and its abnormal reduction is associated with cognitive dysfunction in neurodegenerative diseases. However, the role of SIRT1 in GA-induced neurotoxicity is unclear to date. In this study, we found that the protein level of SIRT1 was inhibited in the hippocampi of developing mice exposed to sevoflurane. Furthermore, the SIRT1 inhibition in hippocampi was associated with brain-derived neurotrophic factor (BDNF) downregulation modulated by methyl-cytosine-phosphate-guanine–binding protein 2 (MeCP2) and cAMP response element-binding protein (CREB). Pretreatment of neonatal mice with resveratrol nearly reversed the reduction in hippocampal SIRT1 expression, which increased the expression of BDNF in developing mice exposed to sevoflurane. Moreover, changes in the levels of CREB and MeCP2, which were considered to interact with BDNF promoter IV, were also rescued by resveratrol. Furthermore, resveratrol improved the cognitive performance in the Morris water maze test of the adult mice with exposure to sevoflurane in the neonatal stage, without changing motor function in the open field test. Taken together, our findings suggested that SIRT1 deficiency regulated BDNF signaling via regulation of the epigenetic activity of MeCP2 and CREB, and resveratrol might be a promising agent for mitigating sevoflurane-induced neurotoxicity in developing mice.

Melatonin and Rapamycin Attenuate Isoflurane-Induced Cognitive Impairment Through Inhibition of Neuroinflammation by Suppressing the mTOR Signaling in the Hippocampus of Aged Mice

Melatonin exerts neuroprotective effects on isoflurane-induced cognitive impairment. However, the underlying mechanism has yet to be elucidated. The present study sought to determine if melatonin confers its beneficial effects by acting on mammalian target of rapamycin (mTOR) and attenuates the neuroinflammation in the hippocampus of aged mice. A total of 72 male C57BL/6 mice, 16-month-old, were randomly and equally divided into six groups: (1) the control group (CON); (2) the rapamycin group (RAP); (3) the melatonin group (MEL); (4) the isoflurane group (ISO); (5) the rapamycin + isoflurane group (RAP + ISO); and (6) the melatonin + isoflurane group (MEL + ISO). RAP, RAP + ISO, MEL, MEL + ISO groups received 1 mg/kg/day mTOR inhibitor rapamycin solution or 10 mg/kg/day melatonin solution, respectively, intraperitoneally at 5:00 p.m. for 14 days consecutively. Mice in the CON and ISO groups were administered an equivalent volume of saline. Subsequently, ISO, RAP + ISO, and MEL + ISO groups were exposed to inhale 2% isoflurane for 4 h; the CON, RAP, and MEL mice received only the vehicle gas. Then, the memory function and spatial learning of the mice were examined via the Morris water maze (MWM) test. mTOR expression was detected via Western blot, whereas the concentration of inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and that of melatonin was quantified with enzyme-linked immunosorbent assay (ELISA). Melatonin and rapamycin significantly ameliorated the isoflurane-induced cognitive impairment and also led to a decrease in the melatonin levels as well as the expression levels of TNF-α, IL-1β, IL-6, and p-mTOR in the hippocampus. In conclusion, these results showed that melatonin and rapamycin attenuates mTOR expression while affecting the downstream proinflammatory cytokines. Thus, these molecular findings could be associated with an improved cognitive function in mice exposed to isoflurane.

General anesthetic neurotoxicity in the young: Mechanism and prevention

General anesthesia (GA) is usually considered to safely induce a reversible unconscious state allowing surgery to be performed without pain. A growing number of studies, in particular pre-clinical studies, however, demonstrate that general anesthetics can cause neuronal death and even long-term neurological deficits. Herein, we report our literature review and meta-analysis data of the neurological outcomes after anesthesia in the young. We also review available mechanistic and epigenetic data of GA exposure related to cognitive impairment per se and the potential preventive strategies including natural herbal compounds to attenuate those side effects. In summary, anesthetic-induced neurotoxicity may be treatable and natural herbal compounds and other medications may have great potential for such use but warrants further study before clinical applications can be initiated.

[Effect of ulinastatin on isoflurane-induced neuronal apoptosis in the hippocampus of rats]

OBJECTIVE

To investigate the effect of ulinastatin pretreatment on isoflurane-induced mitochondria-dependent neuronal apoptosis in the hippocampus of rats.

METHODS

Thirty-six male SD rats were randomly assigned into control group, isoflurane group and ulinastatin group. In the latter two groups, the rats were subjected to acute exposure to 0.75% isoflurane for 6 h and pretreated with 50 000 U/kg of ulinastatin before isoflurane exposure, respectively. After the treatments, apoptosis of the hippocampal neurons was detected using TUNEL assay, and the mitochondrial membrane potential (△ ψm) was measured using JC-1 mitochondrial membrane potential kit; cytochrome C release and caspase-3 activity were examined with Western blotting, and intracellular reactive oxygen species (ROS) was detected using the fluorescent probe H2DCFDA.

RESULTS

Compared with those in the control group, the rats with acute exposure to isoflurane showed markedly increased TUNEL-positive cells in the hippocampus (P &lt; 0.05), which were obviously reduced by ulinastatin pretreatment (P &lt; 0.05). The △ψm of the hippocampal neurons was significantly reduced after isoflurane exposure (P &lt; 0.05), and was partly recovered by ulinastatin pretreatment (P &lt; 0.05). Acute exposure to isoflurane resulted in obviously increased cellular ROS, cytochrome C release and caspase-3 activity in the hippocampal neurons (P &lt; 0.05), and these changes were significantly inhibited by ulinastatin pretreatment (P &lt; 0.05).

CONCLUSIONS

Ulinastatin pretreatment provides neuroprotection against isoflurane-induced apoptosis of the hippocampal neurons in rats possibly by inhibiting mitochondria-dependent apoptosis pathway.

SIRT1 protects against urban particulate matter-induced airway inflammation

Purpose

Particulate matter (PM) has been implicated as a risk factor for airway injury. However, the molecular mechanisms remain largely unclear. The goal of this study was to determine whether sirtuin1 (SIRT1), an anti-inflammatory and antiaging protein, protects against PM-induced airway inflammation.

Methods

The effect of SIRT1 on PM-induced airway inflammation was assessed by using in vivo models of airway inflammation induced by PM and in vitro culture of human bronchial epithelial (HBE) cells exposed to PM, resveratrol (SIRT1 activator), or both.

Results

PM-stimulated HBE cells showed a significant decrease in SIRT1 but a notable increase in inflammatory cytokines. SIRT1 gene silencing further enhanced PM-induced expression of inflammatory cytokines. In contrast, resveratrol, a SIRT1 activator, reduced the expression of these cytokines compared with the control cells. In vivo, SIRT1 expression was significantly decreased in lung tissues of PM-exposed mice. Interestingly, resveratrol treatment reversed the enhanced total cells, neutrophils and inflammatory cytokines in PM-induced mice. Moreover, SIRT1 mediated PM-induced inflammatory cytokines expression at least partly through MAPK pathways.

Conclusion

These findings suggest that SIRT1 is involved in the pathogenesis of PM-induced airway inflammation and activation of SIRT1 could prevent airway disorders or disease exacerbations induced by airborne particulate pollution.

Resveratrol and cognitive decline: a clinician perspective

Resveratrol (3,5,4'-trihydroxystilbene) belongs to a family of polyphenolic compounds known as stilbenes, particularly concentrated in grape and red wine. The aim of our review was to critically review the available evidence of resveratrol effects on brain function and its potential impact on therapy. In preclinical models of cognitive decline, resveratrol displays potent antioxidant activity by scavenging free radicals, reducing quinone reductase 2 activity and upregulating endogenous enzymes. Resveratrol also inhibits pro-inflammatory enzyme expression, reduces nuclear factor-κB activation and cytokine release. Treatment with resveratrol can affect multiple signaling pathway effectors involved in cell survival, programmed cell death and synaptic plasticity. Direct and/or indirect activation of the deacetylase sirtuins by resveratrol has also been suggested. In humans, clinical evidence derived from randomized clinical trials suggests that resveratrol is able to improve cerebral blood flow, cerebral vasodilator responsiveness to hypercapnia, some cognitive tests, perceived performances, and the Aβ₄₀ plasma and cerebrospinal fluid level.

Pre-administration of luteoline attenuates neonatal sevoflurane-induced neurotoxicity in mice

Sevoflurane is a widely used inhaled anesthetic, which triggers neuroapoptosis and oxidative damage in the developing central nervous system and cognitive dysfunction later in life. However, no effective therapeutic strategy for sevoflurane-induced deleterious effects is well developed. The purpose of the present study was to explore whether luteoline could attenuate neonatal sevoflurane exposure-triggered neurotoxicity. In this study, six-day-old C57BL/6 mice were pretreated with luteoline (30, 60 mg/kg) intraperitoneally for 30 min before exposed to 3% sevoflurane 6 h consecutively. We first examined the effects of luteoline on hippocampal neuron apoptosis, inflammation and oxidative stress 18 h post anesthesia. The spatial learning and memory performance was measured using Morris water maze test from postnatal day 31 to 38. The results showed that luteoline ameliorated neuronal apoptosis as evidenced by decrease of apoptotic cells, downregulation of the cleavage levels of caspase-3 and PRAP, and inactivation of caspase-3. Moreover, luteoline significantly decreased protein expressions of inflammatory cytokines (IL-1β, IL-18 and TNF-α), inhibited NF-кB/NLRP3 pathway (NF-кB, NLRP3, ASC and caspase-1) and suppressed NF-кB activity. Our analyses indicated that luteoline had a significant effect on decreasing the contents of ROS and MDA, elevating the activity of SOD, and ultimately improving spatial learning and memory deficits of mice. In summary, our findings confirm that the attenuation of luteoline on sevoflurane-induced spatial learning and memory impairment later is associated with inhibition of hippocampal neuron apoptosis, inflammation and oxidative stress early. Luteoline might be a potential therapeutic for sevoflurane anesthesia-induced neurobehavioral dysfunction.

Obesity caused by a high-fat diet regulates the Sirt1/PGC-1α/FNDC5/BDNF pathway to exacerbate isoflurane-induced postoperative cognitive dysfunction in older mice

Objectives: To investigate the effects of obesity caused by high-fat diet (HFD) on postoperative cognitive dysfunction (POCD) and expression of the Sirt1/PGC-1α/FNDC5/BDNF pathway in the hippocampus of older mice. Methods: Fifty-six 15-month-old male C57BL/6 mice were randomly divided into eight groups - ad libitum control (ALC), ad libitum surgery (ALS), ad libitum surgery with PBS (ALS + PBS), ad libitum surgery with resveratrol (ALS + Res), HFD control (HFC), HFD surgery (HFS), HFD surgery with PBS (HFS + PBS), HFD surgery with resveratrol (HFS + Res). Surgery group mice were exposed to isoflurane before tibial fracture internal fixation. Open field tests and fear conditioning were performed to test motor ability and memory. The levels of expression of Sirt1, PGC-1α, FNDC5, and BDNF were detected using western blot and immunofluorescence. Results: The results of the open field tests indicated there were no between-group differences in motor ability and anxiety. The results of the fear conditioning indicated that the memory of the HFC group and HFS group mice were significantly worse compared with the ALC group and ALS group mice, respectively. There were parallel decreases in expression of the Sirt1/PGC-1α/FNDC5/BDNF pathway in the hippocampi of the HFC and HFS group mice. Resveratrol treatment attenuated the memory loss by increasing hippocampal Sirt1 expression. Expression of the PGC-1α/FNDC5/ BDNF pathway in the CA1 area of the hippocampus was upregulated after resveratrol treatment. Conclusion: An HFD exacerbates POCD in older mice. This change was related to HFD inhibition of expression of the Sirt1/PGC-1α/FNDC5/BDNF pathway in the hippocampus. Resveratrol pretreatment reversed the memory loss via upregulation of this pathway.

The Potential Role of the NLRP3 Inflammasome Activation as a Link Between Mitochondria ROS Generation and Neuroinflammation in Postoperative Cognitive Dysfunction

Postoperative cognitive dysfunction (POCD) is commonly observed in perioperative care following major surgery and general anesthesia in elderly individuals. No preventive or interventional agents have been established so far. Although the role of interleukin-1β (IL-1β)-mediated neuroinflammation following surgery and anesthesia is strongly implicated in POCD, the exact mechanism of action remains to be explored. Growing evidence has shown that mitochondria-derived reactive oxygen species (mtROS) are closely linked to IL-1β expression through a redox sensor known as the nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome. Therefore, we hypothesize that the mechanisms underlying POCD involve the mtROS/NLRP3 inflammasome/IL-1β signaling pathway. Furthermore, we speculate that cholinergic anti-inflammatory pathway induced by α7 nicotinic acetylcholine receptor (a7nAChR) may be the potential upstream of mtROS/NLRP3 inflammasome/IL-1β signaling pathway in POCD. For validating the hypotheses, we provide experimental plan involving different paradigms namely; microglial cells and behavioral studies. The link between mtROS, the NLRP3 inflammasome, and IL-1β within and between these different stages in combination with mtROS and NLRP3 inflammasome agonists and inhibitors could be explored using techniques, such as knockout mice, small interference ribonucleic acid, flow cytometry, co-immunoprecipitation, and the Morris Water Maze test. We conclude that the NLRP3 inflammasome is a new preventive and therapeutic target for POCD.

Postoperative cognitive dysfunction in the aged: the collision of neuroinflammaging with perioperative neuroinflammation

The aging population is burgeoning globally and this trend presents great challenges to the current healthcare system as the growing number of aged individuals receives procedures of surgery and anesthesia. Postoperative cognitive dysfunction (POCD) is a severe postoperative neurological sequela. Advanced age is considered as an independent risk factor of POCD. Mounting evidence have shown that neuroinflammation plays an essential role in POCD. However, it remains debatable why this complication occurs highly in the aged individuals. As known, aging itself is the major common high-risk factor for age-associated disorders including diabetes, cardiovascular disease, cancer, and neurodegenerative diseases. Chronic low-grade neuroinflammation (dubbed neuroinflammaging in the present paper) is a hallmark alternation and contributes to age-related cognitive decline in the normal aging. Interestingly, several lines of findings show that the neuroinflammatory pathogenesis of POCD is age-dependent. It suggests that age-related changes, especially the neuroinflammaging, are possibly associated with the postoperative cognitive impairment. Understanding the role of neuroinflammaging in POCD is crucial to elucidate the mechanism of POCD and develop strategies to prevent or treat POCD. Here the focus of this review is on the potential role of neuroinflammaging in the mechanism of POCD. Lastly, we briefly review promising interventions for this neurological sequela.

Inhibiting the NLRP3 Inflammasome With MCC950 Ameliorates Isoflurane-Induced Pyroptosis and Cognitive Impairment in Aged Mice

Nod-like receptor protein 3 (NLRP3) inflammasome activation has been implicated in the pathogenesis of general anesthesia (GA)-induced neuroinflammation and cognitive impairment in aged rodents. However, the cellular basis for cognitive impairment is still not fully understood, and effective pharmacologic agents targeting the NLRP3 inflammasome during GA are lacking. This study explores the protective effects of the NLRP3 inflammasome inhibitor MCC950 on pyroptosis and cognitive impairment in aged mice exposed to isoflurane. Seventy-two 15-month-old male C57BL/6 mice were randomized to receive 2 h of 1.5% isoflurane plus 30% oxygen (O₂) or 30% O₂ alone, respectively. MCC950 (10 mg/kg) or vehicle was intraperitoneally administered 30 min before gas inhalation. Brain tissues were harvested for histochemical analysis and biochemical assays. Learning and memory abilities were evaluated by behavioral tests. We found that isoflurane GA caused upregulations of hippocampal NLRP3, cleaved caspase-1, interleukin-1β (IL-1β), and IL-18 and the activation of pyroptosis, which is NLRP3 inflammasome-dependent; this consequently gave rise to neuronal damage and cognitive impairment in aged mice. Interestingly, pretreatment with NLRP3 inflammasome inhibitor MCC950 not only provided a neuroprotective effect against the inflammasome activation but also ameliorated pyroptosis and cognitive impairment in aged mice exposed to isoflurane. Our data demonstrate that pyroptosis is involved in NLRP3 inflammasome-mediated isoflurane-induced cognitive impairment in aged mice and suggest that inhibiting the NLRP3 inflammasome with MCC950 may have clinically therapeutic benefits for elderly patients undertaking GA.

Effects of resveratrol pretreatment on endoplasmic reticulum stress and cognitive function after surgery in aged mice

Background

Postoperative cognitive dysfunction (POCD) seriously reduces quality of life and is associated with increased morbidity and mortality. The causes and neuropathogenesis of POCD remain largely unknown. Resveratrol, a sirtuin 1 (Sirt1) activator, is a polyphenol compound found in red wine that has protective functions in neuropathology paradigms. Endoplasmic reticulum stress (ERS) is a primary cellular response that activates the unfolded protein response (UPR). ERS and UPR mediate molecular and biochemical mechanisms related to neurodegeneration; however, the roles of ERS and Sirt1 in POCD remain unclear. The properties of resveratrol might be useful in the setting of POCD.

Methods

In the present study, we investigated learning and memory function and ERS pathways in aged mice after surgery under local anesthesia, and we evaluated the effects of resveratrol pretreatment.

Results

We found that resveratrol attenuated postoperative learning and memory impairment in aged mice postoperatively but did not alter locomotor activity. Resveratrol significantly decreased postoperative expression of ERS pathway UPR-related proteins and inflammatory mediators including nuclear factor-κB (NF-κB) in the hippocampus. This was accompanied by higher Sirt1 protein expression levels. Pretreatment with resveratrol did not affect the number of hippocampal neurons in aged mice after surgery.

Conclusion

Overall, resveratrol pretreatment attenuated short-term learning and memory impairment and the ERS pathway UPR in aged mice after surgery under local anesthesia.

NLRP3 inflammasome-dependent pyroptosis is proposed to be involved in the mechanism of age-dependent isoflurane-induced cognitive impairment

Wang Z et al. recently published a paper, titled “Critical role of NLRP3-caspase-1 pathway in age-dependent isoflurane-induced microglial inflammatory response and cognitive impairment”. The finding in this paper is consistent with our previous study on NLRP3-caspase-1 pathway. Here, we propose that NLRP3 inflammasome-dependent pyroptosis may be involved in the mechanism of age-dependent isoflurane-induced cognitive impairment and discuss that inhibiting NLRP3 inflammasome activation with a novel inhibitor MCC950 may ameliorate age-dependent isoflurane-induced neuro-inflammation.

Thioredoxin-interacting protein mediates mitochondrion-dependent apoptosis in early brain injury after subarachnoid hemorrhage

Early brain injury (EBI) was reported to be the primary cause of high mortality and poor outcomes in subarachnoid hemorrhage (SAH) patients, and apoptosis is regarded as the most important physiopathologic mechanism during EBI. Recently, our team found that thioredoxin-interacting protein (TXNIP) links endoplasmic reticulum stress (ER stress) to neuronal apoptosis and aggravates EBI. However, the other underlying mechanisms remain unknown. Mitochondria are considered to be the central points in integrating apoptotic cell death. However, whether crosstalk between TXNIP and the mitochondria-mediated intrinsic apoptotic pathway is effective on EBI has not been previously reported. Therefore, we created an endovascular perforation SAH model in Sprague-Dawley rats to determine the possible mechanism. We found that TXNIP expression in apoptotic neurons significantly increased in the SAH group compared with the sham group. In addition, increased TXNIP expression was accompanied by remarkable changes in mitochondrial-related antiapoptotic and proapoptotic factors. Furthermore, resveratrol (RES, a TXNIP inhibitor) administration significantly downregulated the expression of TXNIP and mitochondria-related proapoptotic factors. Additionally, it attenuated SAH prognostic indicators, such as brain edema, blood-brain barrier permeability, and neurological deficits. Therefore, our study further confirms that TXNIP may participate in neuronal apoptosis through the mitochondrial signaling pathway and that TXNIP may be a target for SAH treatment.

Critical role of NLRP3-caspase-1 pathway in age-dependent isoflurane-induced microglial inflammatory response and cognitive impairment

Background

Elderly patients are more likely to suffer from postoperative cognitive dysfunction (POCD) after surgery and anesthesia. Except for declined organ function, the particular pathogenesis of POCD in elderly patients remains unknown. This study is carried out to determine the critical role of the NOD-like receptor protein 3 (NLRP3)-caspase-1 pathway in isoflurane-induced cognitive impairment.

Methods

Young (6–8 months old) and aged (14 months old) healthy male C57BL/6 mice were exposed to 1.5% isoflurane for 2 h. Some mice received intraperitoneal injection of Ac-YVAD-cmk (8 mg/kg), a specific inhibitor of caspase-1, 30 min before the isoflurane exposure. Morris water maze test was carried out 1 week after the isoflurane anesthesia. Brain tissues were harvested 24 h after the isoflurane anesthesia. Western blotting was carried out to detect the expression of NLRP3, interleukin (IL)-1β, and IL-18 in the hippocampus. Mouse microglial cell line BV-2 and primary microglial cultures were primed by lipopolysaccharide for 30 min before being exposed to isoflurane. NLRP3 was downregulated by RNA interference.

Results

Compared to young mice, aged mice had an increased expression of NLRP3 in the hippocampus. Isoflurane induced cognitive impairment and hippocampal inflammation in aged mice but not in young mice. These effects were attenuated by Ac-YVAD-cmk pretreatment (P < 0.05). Isoflurane activated NLRP3-caspase-1 pathway and increased the secretion of IL-18 and IL-1β in cells pretreated with lipopolysaccharide but not in cells without pretreatment. Downregulation of NLRP3 attenuated the activation of NLRP3 inflammasome by isoflurane.

Conclusions

NLRP3 priming status in aged mouse brain may be involved in isoflurane-induced hippocampal inflammation and cognitive impairment.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1137-1) contains supplementary material, which is available to authorized users.

MicroRNA-383 upregulation protects against propofol-induced hippocampal neuron apoptosis and cognitive impairment

Anesthesia-induced cognitive impairment is a recognized clinical phenomenon. The present study aimed to investigate the effect of microRNA-383 (miR-383) expression on propofol-induced learning and memory impairment. In total, 48 male Sprague-Dawley rats (weight, 250±10 g) were randomly divided into four groups (n=12 each): Control group, and three groups of rats that were anesthetized with propofol for 6 h and untreated (propofol model group), treated with a constructed lentivirus vector expressing miR-383 mimics (mimic + propofol group), or treated with miR-383 scramble (scramble + propofol group). The learning memory ability, hippocampal neuron apoptosis and expression of apoptosis-associated factors were detected using reverse transcription-quantitiative polymerase chain reaction and western blot analysis. Propofol treatment significantly reduced the relative mRNA and protein expression of miR-383, induced neuron apoptosis, upregulated the Bax/Bcl-2 ratio, downregulated the relative mRNA and protein expression levels of postsynaptic density protein 95 and cAMP-response element binding protein, and inactivated the phosphoinositide 3-kinase/protein kinase B signaling pathway. By contrast, miR-383 mimics significantly altered the propofol-induced dysregulation of the aforementioned factors. In conclusion, miR-383 mimic was able to repair propofol-induced cognitive impairment via protecting against hippocampal neuron apoptosis and dysregulation of related factors. The present study suggested that miR-383 may be used as a potential therapeutic target for the clinical treatment of cognitive impairment induced by propofol anesthesia.

Metabolism and pharmacokinetics of resveratrol and pterostilbene

Beneficial properties of resveratrol and pterostilbene, a dimethyl ether analog of resveratrol, have attracted increasing interest in recent years. Resveratrol and pterostilbene exhibit many pharmacological similarities and both of them are generally considered to be safe for human consumption. Beyond the structural and general bioactivity similarities between them, large amounts of data are now available to reveal the metabolic fate and pharmacological differences between them. Pterostilbene was found to be more metabolically stable and usually exhibited stronger pharmacological activities than that of resveratrol. As a contribution to clarify and compare aspects like metabolic stability and pharmacokinetics of resveratrol and pterostilbene, as well as explain the pharmacological similarities and differences between them, this review presents and compares recent data on the metabolism and pharmacokinetics of resveratrol and pterostilbene. © 2018 BioFactors, 44(1):16-25, 2018.

Sevoflurane Induces Exaggerated and Persistent Cognitive Decline in a Type II Diabetic Rat Model by Aggregating Hippocampal Inflammation

Recent studies show that a moderate duration of sevoflurane, one of the most commonly used volatile anesthetics in clinical practice, does not induce cognitive impairment in animals under physiological conditions. However, the influence of sevoflurane on cognitive function under diabetic conditions remains unclear. The aim of this study was to determine whether sevoflurane causes cognitive decline in a rat model of type 2 diabetes mellitus (DM) and if so, to explore a possible underlying mechanism. Diabetic Goto–Kakizaki (GK) rats and non-diabetic Wistar rats underwent 2.6% sevoflurane for 4 h or sham (control) exposure. Cognitive function and hippocampal inflammation were assessed 1 week and 5 months after sevoflurane or sham exposure. Compared with Wistar control rats, GK control rats exhibited shorter freezing times in Trace fear conditioning task 1 week after exposure, took longer to locate the submerged platform and had shorter dwell-time in the target quadrant in Morris Water Maze task 5 months after exposure. GK rats that received sevoflurane not only exhibited less freezing times 1 week after exposure, but also spent more time to locate the submerged platform and had less dwell-time in the target quadrant, compared with GK control rats. Molecular studies revealed that the levels of pro-inflammatory cytokines and activated microglia in the hippocampus were higher in GK control rats than those in Wistar control rats at both time points and were further increased in GK rats receiving sevoflurane. Wistar rats that received sevoflurane and Wistar control rats did not differ in any cognitive performance and molecular assessment. The results suggest that diabetic GK rats exhibit cognitive dysfunction probably due to increased hippocampal inflammation, and that sevoflurane induces exaggerated and persistent cognitive decline in GK rat by aggregating hippocampal inflammation.

Resveratrol Attenuates Neurodegeneration and Improves Neurological Outcomes after Intracerebral Hemorrhage in Mice

Intracerebral hemorrhage (ICH) is a devastating type of stroke with a substantial public health impact. Currently, there is no effective treatment for ICH. The purpose of the study was to evaluate whether the post-injury administration of Resveratrol confers neuroprotection in a pre-clinical model of ICH. To this end, ICH was induced in adult male CD1 mice by collagenase injection method. Resveratrol (10 mg/kg) or vehicle was administered at 30 min post-induction of ICH and the neurobehavioral outcome, neurodegeneration, cerebral edema, hematoma resolution and neuroinflammation were assessed. The Resveratrol treatment significantly attenuated acute neurological deficits, neurodegeneration and cerebral edema after ICH in comparison to vehicle treated controls. Further, Resveratrol treated mice exhibited improved hematoma resolution with a concomitant reduction in the expression of proinflammatory cytokine, IL-1β after ICH. Altogether, the data suggest the efficacy of post-injury administration of Resveratrol in improving acute neurological function after ICH.

Immune Modulation by Volatile Anesthetics

Volatile general anesthetics continue to be an important part of clinical anesthesia worldwide. The impact of volatile anesthetics on the immune system has been investigated at both mechanistic and clinical levels, but previous studies have returned conflicting findings due to varied protocols, experimental environments, and subject species. While many of these studies have focused on the immunosuppressive effects of volatile anesthetics, compelling evidence also exists for immunoactivation. Depending on the clinical conditions, immunosuppression and activation due to volatile anesthetics can be either detrimental or beneficial. This review provides a balanced perspective on the anesthetic modulation of innate and adaptive immune responses as well as indirect effectors of immunity. Potential mechanisms of immunomodulation by volatile anesthetics are also discussed. A clearer understanding of these issues will pave the way for clinical guidelines that better account for the impact of volatile anesthetics on the immune system, with the ultimate goal of improving perioperative management.

Protective Effect of Resveratrol on the Brain in a Rat Model of Epilepsy

Accumulating evidence has suggested resveratrol as a promising drug candidate for the treatment of epilepsy. To validate this, we tested the protective effect of resveratrol on a kainic acid (KA)-induced epilepsy model in rats and investigated the underlying mechanism. We found that acute resveratrol application partially inhibited evoked epileptiform discharges in the hippocampal CA1 region. During acute, silent and chronic phases of epilepsy, the expression of hippocampal kainate glutamate receptor (GluK2) and the GABAA receptor alpha1 subunit (GABAAR-alpha1) was up-regulated and down-regulated, respectively. Resveratrol reversed these effects and induced an antiepileptic effect. Furthermore, in the chronic phase, resveratrol treatment inhibited the KA-induced increased glutamate/GABA ratio in the hippocampus. The antiepileptic effects of resveratrol may be partially attributed to the reduction of glutamate-induced excitotoxicity and the enhancement in GABAergic inhibition.