Protective Effect of Ergothioneine against 7-Ketocholesterol-Induced Mitochondrial Damage in hCMEC/D3 Human Brain Endothelial Cells.

Recent findings have suggested that the natural compound ergothioneine (ET), which is synthesised by certain fungi and bacteria, has considerable cytoprotective potential. We previously demonstrated the anti-inflammatory effects of ET on 7-ketocholesterol (7KC)-induced endothelial injury in human blood-brain barrier endothelial cells (hCMEC/D3). 7KC is an oxidised form of cholesterol present in atheromatous plaques and the sera of patients with hypercholesterolaemia and diabetes mellitus. The aim of this study was to elucidate the protective effect of ET on 7KC-induced mitochondrial damage. Exposure of human brain endothelial cells to 7KC led to a loss of cell viability, together with an increase in intracellular free calcium levels, increased cellular and mitochondrial reactive oxygen species, a decrease in mitochondrial membrane potential, reductions in ATP levels, and increases in mRNA expression of TFAM, Nrf2, IL-1ß, IL-6 and IL-8. These effects were significantly decreased by ET. Protective effects of ET were diminished when endothelial cells were coincubated with verapamil hydrochloride (VHCL), a nonspecific inhibitor of the ET transporter OCTN1 (SLC22A4). This outcome demonstrates that ET-mediated protection against 7KC-induced mitochondrial damage occurred intracellularly and not through direct interaction with 7KC. OCTN1 mRNA expression itself was significantly increased in endothelial cells after 7KC treatment, consistent with the notion that stress and injury may increase ET uptake. Our results indicate that ET can protect against 7KC-induced mitochondrial injury in brain endothelial cells.

Protective Effect of Ergothioneine Against Stroke in Rodent Models.

Ergothioneine (ET) is a naturally occurring antioxidant and cytoprotective agent that is synthesized by fungi and certain bacteria. Recent studies have shown a beneficial effect of ET on neurological functions, including cognition and animal models of depression. The aim of this study is to elucidate a possible effect of ET in rodent models of stroke. Post-ischemic intracerebroventricular (i.c.v.) infusion of ET significantly reduced brain infarct volume by as early as 1 day after infusion in rats, as shown by triphenyltetrazolium chloride (TTC) assay. There was a dose-dependent increase in protection, from 50 to 200 ng of ET infusion. These results suggest that ET could have a protective effect on CNS neurons. We next elucidated the effect of systemic ET on brain infarct volume in mice after stroke. Daily i.p. injection of 35 mg/kg ET (the first dose being administered 3 h after stroke) had no significant effect on infarct volume. However, daily i.p. injections of 70 mg/kg, 100 mg/kg, 125 mg/kg and 150 mg/kg ET, with the first dose administered 3 h after stroke, significantly decreased infarct volume at 7 days after vessel occlusion in mice. In order to elucidate at what time interval during the 7 days there could be effective protection, a second set of experiments was carried out in mice, using one of the effective loading protocols, i.e. 125 mg/kg i.p. ET but the brains were analyzed at 1, 4 and 7 days post-stroke by MRI. We found that ET was already protective against neuronal injury and decreased the size of the brain infarct from as early as 1 day post-stroke. Behavioral experiments carried out on a third set of mice (using 125 mg/kg i.p. ET) showed that this was accompanied by significant improvements in certain behaviors (pole test) at 1 day after stroke. Together, results of this study indicate that i.c.v. and systemic ET are effective in reducing brain infarct volume after stroke in rodent models.

Mindfulness Awareness Practice (MAP) to Prevent Dementia in Older Adults with Mild Cognitive Impairment: Protocol of a Randomized Controlled Trial and Implementation Outcomes.

BACKGROUND: With an aging population, developing non-pharmacological interventions (NPIs) to delay dementia has become critical. Apart from cognitive decline, dementia is associated with multiple pathophysiology, including increased oxidative stress, dysregulated gene expressions, cytokine, neurotrophin, and stress markers, telomere shortening, and deteriorations in brain connectivity. Although mindfulness practices have been proposed to ameliorate these biological changes, no empirical studies were conducted. We thus aimed to investigate the effects of mindfulness awareness practice (MAP) to prevent cognitive decline and improve peripheral biomarkers in community-dwelling older adults diagnosed with mild cognitive impairment (MCI). METHODS/DESIGN: This was a single-blinded and parallel-group randomized controlled trial with two arms (intervention and active control arms), conducted over nine months. A total of 60 consenting community-dwelling older adults diagnosed with MCI were planned to be randomized in a 1:1 ratio to either the MAP or the Health Education Program (HEP). Interventions were performed weekly for the initial 12 weeks, and monthly for the subsequent six months. Outcome measures were assessed at baseline, 3-month, and 9-month post-intervention by blinded assessors. Primary outcomes were neurocognitive tests, comprehensive peripheral biomarkers, and brain imaging scans. Secondary outcomes included basic health screening measures, affective symptoms, and measures of physical functions. Linear-mixed models were used to examine the effects of MAP on these outcome measures. SIGNIFICANCE: This is the first randomized controlled trial to systematically investigate the effects of a mindfulness intervention in improving cognitive functions and various biomarkers in community-dwelling older adults diagnosed with MCI. Our findings have the potential to inform mindfulness intervention as a novel approach to delay dementia.

Effects of Antimalarial Drugs on Neuroinflammation-Potential Use for Treatment of COVID-19-Related Neurologic Complications.

The SARS-CoV-2 virus that is the cause of coronavirus disease 2019 (COVID-19) affects not only peripheral organs such as the lungs and blood vessels, but also the central nervous system (CNS)-as seen by effects on smell, taste, seizures, stroke, neuropathological findings and possibly, loss of control of respiration resulting in silent hypoxemia. COVID-19 induces an inflammatory response and, in severe cases, a cytokine storm that can damage the CNS. Antimalarials have unique properties that distinguish them from other anti-inflammatory drugs. (A) They are very lipophilic, which enhances their ability to cross the blood-brain barrier (BBB). Hence, they have the potential to act not only in the periphery but also in the CNS, and could be a useful addition to our limited armamentarium against the SARS-CoV-2 virus. (B) They are non-selective inhibitors of phospholipase A2 isoforms, including cytosolic phospholipase A2 (cPLA2). The latter is not only activated by cytokines but itself generates arachidonic acid, which is metabolized by cyclooxygenase (COX) to pro-inflammatory eicosanoids. Free radicals are produced in this process, which can lead to oxidative damage to the CNS. There are at least 4 ways that antimalarials could be useful in combating COVID-19. (1) They inhibit PLA2. (2) They are basic molecules capable of affecting the pH of lysosomes and inhibiting the activity of lysosomal enzymes. (3) They may affect the expression and Fe2+/H+ symporter activity of iron transporters such as divalent metal transporter 1 (DMT1), hence reducing iron accumulation in tissues and iron-catalysed free radical formation. (4) They could affect viral replication. The latter may be related to their effect on inhibition of PLA2 isoforms. Inhibition of cPLA2 impairs an early step of coronavirus replication in cell culture. In addition, a secretory PLA2 (sPLA2) isoform, PLA2G2D, has been shown to be essential for the lethality of SARS-CoV in mice. It is important to take note of what ongoing clinical trials on chloroquine and hydroxychloroquine can eventually tell us about the use of antimalarials and other anti-inflammatory agents, not only for the treatment of COVID-19, but also for neurovascular disorders such as stroke and vascular dementia.

Effect of Ergothioneine on 7-Ketocholesterol-Induced Endothelial Injury.

Ergothioneine (ET) is a naturally occurring antioxidant that is synthesized by non-yeast fungi and certain bacteria. ET is not synthesized by animals, including humans, but is avidly taken up from the diet, especially from mushrooms. In the current study, we elucidated the effect of ET on the hCMEC/D3 human brain endothelial cell line. Endothelial cells are exposed to high levels of the cholesterol oxidation product, 7-ketocholesterol (7KC), in patients with cardiovascular disease and diabetes, and this process is thought to mediate pathological inflammation. 7KC induces a dose-dependent loss of cell viability and an increase in apoptosis and necrosis in the endothelial cells. A relocalization of the tight junction proteins, zonula occludens-1 (ZO-1) and claudin-5, towards the nucleus of the cells was also observed. These effects were significantly attenuated by ET. In addition, 7KC induces marked increases in the mRNA expression of pro-inflammatory cytokines, IL-1ß IL-6, IL-8, TNF-α and cyclooxygenase-2 (COX2), as well as COX2 enzymatic activity, and these were significantly reduced by ET. Moreover, the cytoprotective and anti-inflammatory effects of ET were significantly reduced by co-incubation with an inhibitor of the ET transporter, OCTN1 (VHCL). This shows that ET needs to enter the endothelial cells to have a protective effect and is unlikely to act via extracellular neutralizing of 7KC. The protective effect on inflammation in brain endothelial cells suggests that ET might be useful as a nutraceutical for the prevention or management of neurovascular diseases, such as stroke and vascular dementia. Moreover, the ability of ET to cross the blood-brain barrier could point to its usefulness in combatting 7KC that is produced in the CNS during neuroinflammation, e.g. after excitotoxicity, in chronic neurodegenerative diseases, and possibly COVID-19-related neurologic complications.

Cohort profile: the Diet and Healthy Aging (DaHA) study in Singapore.

How diet is related with cognition and health has not been systematically examined in Asians whose eating habits are very different from their counterparts in the West and the biological mechanisms underlying such links are not well known yet. The diet and healthy aging (DaHA) study is a community-based longitudinal study conducted to examine the role of diet and nutrition in promoting cognitive, emotional, and physical health among community-living elderly Singaporeans. The first wave of DaHA, conducted from 2011 to 2017, provided detailed information on diet and baseline cognitive function and health from 1010 community-living elderly in Singapore. Biomarkers of oxidative stress, systemic inflammation, and genetic information were collected. The ongoing second wave of DaHA is conducted from 2017 to 2020, which provides follow- up assessments using established cognitive tests and clinical tools. This well-characterized cohort, with its archived biological samples and high-quality data on diet and lifestyle factors will allow researchers to explore the relationships among diet, nutrition, genes, cognition, mental and physical health in an extremely cost-effective manner. Translations of the research findings into clinical and public health practices will potentially help to promote cognitive health at the population level and reduce healthcare costs related to cognitive impairment.

Mindfulness improves inflammatory biomarker levels in older adults with mild cognitive impairment: a randomized controlled trial.

Few randomized controlled trials investigated the effects of mindfulness intervention on older adults diagnosed with mild cognitive impairment (MCI). Furthermore, there have been hypotheses and theoretical mechanisms on the benefits of mindfulness intervention on biomarkers of stress, inflammation, and neuroplasticity implicated in MCI that warrant empirical evidence. We conducted a pilot randomized controlled trial to examine whether Mindful Awareness Practice (MAP) improved biomarker levels in older adults with MCI. Fifty-five community-dwelling older adults aged 60 and above were randomized into either the treatment arm, MAP, or the active control arm, the health education program (HEP). Researchers who were blinded to treatment allocation assessed the outcomes at baseline, 3-month, and 9-month follow-ups. Linear-mixed models were used to examine the effect of MAP on biomarker levels. MAP participants had significantly decreased high-sensitivity c-reactive protein (hs-CRP) levels at 9-month (ß = -0.307, 95% CI = -0.559 to -0.054 P = 0.018). Exploratory sub-group analyses by sex showed significantly decreased hs-CRP in females only (ß = -0.445, 95% CI = -0.700 to -0.189, P = 0.001), while stratification by MCI subtype showed hs-CRP decreased only in amnestic-MCI (aMCI) (ß = -0.569, 95% CI = -1.000 to -0.133, P = 0.012). Although total sample analyses were not significant, males had significantly decreased interleukin (IL)-6 (ß = -1.001, 95% CI = -1.761 to -0253, P = 0.011) and IL-1ß (ß = -0.607, 95% CI = -1.116 to -0.100, P = 0.021) levels at 3-month and non-significant improvements at 9-month time-point. MAP improved inflammatory biomarkers in sex- and MCI subtype-specific manners. These preliminary findings suggest the potential of mindfulness intervention as a self-directed and low-cost preventive intervention in improving pathophysiology implicated in MCI.

The Association between Mushroom Consumption and Mild Cognitive Impairment: A Community-Based Cross-Sectional Study in Singapore.

We examined the cross-sectional association between mushroom intake and mild cognitive impairment (MCI) using data from 663 participants aged 60 and above from the Diet and Healthy Aging (DaHA) study in Singapore. Compared with participants who consumed mushrooms less than once per week, participants who consumed mushrooms >2 portions per week had reduced odds of having MCI (odds ratio = 0.43, 95% CI 0.23-0.78, p = 0.006) and this association was independent of age, gender, education, cigarette smoking, alcohol consumption, hypertension, diabetes, heart disease, stroke, physical activities, and social activities. Our cross-sectional data support the potential role of mushrooms and their bioactive compounds in delaying neurodegeneration.

Study Protocol for a Randomized Controlled Trial of Choral Singing Intervention to Prevent Cognitive Decline in At-Risk Older Adults Living in the Community.

Introduction: This study is a parallel-arm randomized controlled trial evaluating choral singing's efficacy and underlying mechanisms in preventing cognitive decline in at-risk older participants. Methods: Three-hundred and sixty community-dwelling, non-demented older participants are recruited for a 2-year intervention. Inclusion criteria are self-reported cognitive complaints, early cognitive impairment based on neuropsychological test scores or multiple risk factors of dementia. Participants are randomized to either weekly choral singing sessions or general health education. The primary outcome is cognitive performance, measured by a composite cognitive test score (CCTS). Secondary outcomes include depression, anxiety and neuropsychiatric symptoms; perceived stress; sleep quality and severity of dementia symptoms. Underlying mechanisms are examined using blood- and urine-based biomarkers and neuroimaging. Results: Screening began in July 2016. The first group of participants (n = 93) have been recruited. Intervention and control treatments are ongoing and will end in December 2019. Discussion: An evidence-based singing intervention for dementia prevention holds potential for healthcare savings and societal welfare. Trial Registration: NCT02919748, IRB Approval Number: NUS 2508.

Dataset on gene expression in the elderly after Mindfulness Awareness Practice or Health Education Program.

It has been reported that relaxation techniques can improve physical health and cognitive function. A number of studies involving different types of relaxation practices showed changes in expression of genes. We investigated the gene expression pattern of a cohort of elderly subjects of Asian descent after weekly (for the first three months) and monthly (for the subsequent six months) intervention. Sixty consenting elderly subjects (aged 60-90 years) with mild cognitive impairment were assigned to either the Mindfulness Awareness Practice (MAP) or Health Education Program (HEP) group in a randomized controlled trial to assess the effectiveness of the programs in preventing further cognitive decline and evaluate the influence on neurological, cellular and biochemical factors. Blood samples were collected before the start of intervention and after nine months for gene expression profiling using Affymetrix Human Genome U133 Plus 2.0 arrays. The dataset is publicly available for further analyses.

Distribution and accumulation of dietary ergothioneine and its metabolites in mouse tissues.

L-ergothioneine (ET) is a diet-derived amino acid that accumulates at high concentrations in animals and humans. Numerous studies have highlighted its antioxidant abilities in vitro, and possible cytoprotective capabilities in vivo. We investigated the uptake and distribution of ET in various organs by a highly sensitive and specific liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) technique, both before and after oral administration of pure ET (35 and 70 mg/kg/day for 1, 7, and 28 days) to male C57BL6J mice. ET primarily concentrates in the liver and whole blood, and also in spleen, kidney, lung, heart, intestines, eye, and brain tissues. Strong correlations were found between ET and its putative metabolites - hercynine, ET-sulfonate (ET-SO3H), and S-methyl ET. Hercynine accumulates in the brain after prolonged ET administration. This study demonstrates the uptake and distribution of ET and provides a foundation for future studies with ET to target oxidative damage in a range of tissues in human diseases.