Green tea extract containing enhanced levels of epimerized catechins attenuates scopolamine-induced memory impairment in mice

Dimethysiloxane polymer for the effective transdermal delivery of donepezil in Alzheimer's disease treatment

Donepezil (DNZ) has been used to treat dementia associated with mild, moderate, or severe Alzheimer's disease (AD). DNZ uptake can alleviate cognitive symptoms in AD patients via acetylcholinesterase (AChE) inhibition. However, oral administration of DNZ has limitations, including first-pass metabolism, difficulties with swallowing, and low patient compliance. In this work, we disclose a novel transdermal DNZ delivery system utilizing T2 polymer, synthesized via the ring-opening polymerization of 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentane with trifluoroacetic acid (TFA). In the in vivo studies in an AD animal model, the DNZ-loaded T2 polymer (DNZ@T2) facilitated efficient transdermal DNZ delivery to the bloodstream and improved spatial working memory and long-term memory of the AD mouse model. Both the T2 polymer and DNZ@T2 exhibited low cytotoxicity and non-significant in vivo toxicity. This research highlights a promising transdermal delivery strategy for AD treatment, potentially enhancing therapeutic efficacy and patient compliance.

Nelumbo nucifera leaves extract ameliorated scopolamine-induced cognition impairment via enhanced adult hippocampus neurogenesis

In this presentation, we explored the molecular mechanisms of N. nucifera leaf water extracts (NLWEs) and polyphenol extract (NLPE) on scopolamine-induced cell apoptosis and cognition defects. The administration of NLWE and NLPE did not alter the body weight and serum biomarker rs and significantly ameliorated scopolamine-induced cognition impairment according to Y-maze test analysis. In mice, treatment with scopolamine disrupted normal histoarchitecture in the hippocampus, whereas the administration of NLWE and NLPE reversed the phenomenon. Western blot analysis revealed that scopolamine mitigated the expression of doublecortin (DCX), nestin, and NeuN, and cotreatment with NLWE or NLPE significantly recovered the expression of these proteins. NLWE and NLPE upregulated DCX and NeuN expression in the hippocampus region, as evidenced by immunohistochemical staining analysis of scopolamine-treated mice. NLWE and NLPE obviously elevated brain-derived neurotrophic factor (BDNF) and enhanced its downstream proteins activity. NLWE and NLPE attenuated scopolamine-induced apoptosis by reducing Bax and increased Bcl-2 expression. In addition, scopolamine also triggered apoptosis in human neuroblastoma SH-SY5Y cells whereas co-treatment with NLWE or quercetin-3-glucuronide (Q3G) reversed the phenomenon. NLWE or Q3G enhanced Bcl-2 and reduced Bax expression in the presence of scopolamine in SH-SY5Y cells. NLWE or Q3G recovered the inhibitory effects of scopolamine on neurogenesis and BDNF signals in SH-SY5Y cells. Overall, our results revealed that N. nucifera leaf extracts and Q3G promoted adult hippocampus neurogenesis and prevented apoptosis to mitigate scopolamine-induced cognition dysfunction through the regulation of BDNF signaling pathway.

LPC20K modified from krill oil ameliorates the scopolamine-induced cognitive impairment

Alzheimer's disease (AD) is characterized by cognitive impairment. It is common in the elderly. Etiologically, dysfunction of cholinergic neurotransmitter system is prominent in AD. However, disease modifying drug for AD is still unavailable. We hypothesized that krill oil and modified krill oil containing 20 % lysophosphatidylcholine-docosahexaenoic acid (LPC-DHA, LPC20K) could play a crucial role in AD by improving cognitive functions measured by several behavioral tests. We found that LPC20K could ameliorate short-term, long-term, spatial, and object recognition memory under cholinergic hypofunction states. To find the underlying mechanism involved in the effect of LPC20K on cognitive function, we investigated changes of signaling molecules using Western blotting. Expression levels of protein kinase C zeta (PKCζ) and postsynaptic density protein 95 (PSD-95), and phosphorylation levels of extracellular signal-regulated kinase (ERK), Ca2+/calmodulin-dependent protein kinase Ⅱ (CaMKⅡ), and cAMP response element-binding protein (CREB) were significantly increased in LPC20K-administered group compared to those in the memory impairment group. Moreover, the expression levels of BDNF were temporally increased especially 6 or 9 h after administration of LPC20K compared with the control group. These results suggest that LPC20K could ameliorate memory impairment caused by hypocholinergic state by enhancing the expression levels of PKCζ and PSD-95, and phosphorylation levels of ERK, CaMKⅡ and CREB and increasing BDNF expression levels. Therefore, LPC20K could be used as a dietary supplement against cognitive impairment observed in diseases such as AD with a hypocholinergic state.

Impact of micronutrients and nutraceuticals on cognitive function and performance in Alzheimer's disease

Alzheimer's disease (AD) is a major global health problem today and is the most common form of dementia. AD is characterized by the formation of β-amyloid (Aβ) plaques and neurofibrillary clusters, leading to decreased brain acetylcholine levels in the brain. Another mechanism underlying the pathogenesis of AD is the abnormal phosphorylation of tau protein that accumulates at the level of neurofibrillary aggregates, and the areas most affected by this pathological process are usually the cholinergic neurons in cortical, subcortical, and hippocampal areas. These effects result in decreased cognitive function, brain atrophy, and neuronal death. Malnutrition and weight loss are the most frequent manifestations of AD, and these are also associated with greater cognitive decline. Several studies have confirmed that a balanced low-calorie diet and proper nutritional intake may be considered important factors in counteracting or slowing the progression of AD, whereas a high-fat or hypercholesterolemic diet predisposes to an increased risk of developing AD. Especially, fruits, vegetables, antioxidants, vitamins, polyunsaturated fatty acids, and micronutrients supplementation exert positive effects on aging-related changes in the brain due to their antioxidant, anti-inflammatory, and radical scavenging properties. The purpose of this review is to summarize some possible nutritional factors that may contribute to the progression or prevention of AD, understand the role that nutrition plays in the formation of Aβ plaques typical of this neurodegenerative disease, to identify some potential therapeutic strategies that may involve some natural compounds, in delaying the progression of the disease.

Panaxcerol D from Panax ginseng ameliorates the memory impairment induced by cholinergic blockade or Aβ25-35 peptide in mice

Background

Alzheimer's disease (AD) has memory impairment associated with aggregation of amyloid plaques and neurofibrillary tangles in the brain. Although anti-amyloid β (Aβ) protein antibody and chemical drugs can be prescribed in the clinic, they show adverse effects or low effectiveness. Therefore, the development of a new drug is necessarily needed. We focused on the cognitive function of Panax ginseng and tried to find active ingredient(s). We isolated panaxcerol D, a kind of glycosyl glyceride, from the non-saponin fraction of P. ginseng extract.

Methods

We explored effects of acute or sub-chronic administration of panaxcerol D on cognitive function in scopolamine- or Aβ25-35 peptide-treated mice measured by several behavioral tests. After behavioral tests, we tried to unveil the underlying mechanism of panaxcerol D on its cognitive function by Western blotting.

Results

We found that pananxcerol D reversed short-term, long-term and object recognition memory impairments. The decreased extracellular signal-regulated kinases (ERK) or Ca2+/calmodulin-dependent protein kinase II (CaMKII) in scopolamine-treated mice was normalized by acute administration of panaxcerol D. Glial fibrillary acidic protein (GFAP), caspase 3, NF-kB p65, synaptophysin and brain-derived neurotrophic factor (BDNF) expression levels in Aβ25-35 peptide-treated mice were modulated by sub-chronic administration of panaxcerol D.

Conclusion

Pananxcerol D could improve memory impairments caused by cholinergic blockade or Aβ accumulation through increased phosphorylation level of ERK or its anti-inflammatory effect. Thus, panaxcerol D as one of non-saponin compounds could be used as an active ingredient of P. ginseng for improving cognitive function.

Effects of Artemisia annua L. on postmenopausal syndrome in ovariectomized mice

ETHNOPHARMACOLOGICAL RELEVANCE

Artemisia annua L. (Asteraceae) has been used as an antipyretic and anti-parasitic drug in traditional medicine for more than 2000 years. It has also been prescribed to treat symptoms caused by deficiency of Yin, which might be observed in menopausal state from the point of view of traditional medicine.

AIM OF THE STUDY

We hypothesized that A. annua might be useful for treating menopausal disorders with less adverse effects than hormone replacement therapy. Thus, the aim of the present study was to investigate effects of A. annua on postmenopausal symptoms of ovariectomized (OVX) mice.

MATERIALS AND METHODS

OVX mice were employed as a model for postmenopausal disorders. Mice were treated with a water extract of A. annua (EAA; 30, 100 or 300 mg/kg, p.o.) or 17β-estradiol (E2; 0.5 mg/kg, s.c.) for 8 weeks. Open field test (OFT), novel object recognition task (NOR), Y-maze test, elevated plus maze test (EPM), splash test and tail suspension test (TST) were conducted to determine whether EAA could ameliorate postmenopausal symptoms. Phosphorylated levels of extracellular signal-regulated kinase (ERK), protein kinase B (Akt), and glycogen synthase kinase-3β (GSK-3β), β-catenin and expression level of synaptophysin in the cortex and hippocampus were evaluated by Western blot analysis.

RESULTS

EAA treatment significantly increased the discrimination index in NOR, decreased the time in closed arm than in open arm in EPM, increased grooming time in splash test, and decreased immobility time in TST, as did E2 treatment. In addition, decreased phosphorylation levels of ERK, Akt, GSK-3β, and β-catenin and expression levels of synaptophysin in the cortex and hippocampus after OVX were reversed by administration of EAA and E2.

CONCLUSION

These results suggest that A. annua can ameliorate postmenopausal symptoms such as cognitive dysfunction, anxiety, anhedonia, and depression by activating ERK, Akt, and GSK-3β/β-catenin signaling pathway and hippocampal synaptic plasticity, and that A. annua would be a novel treatment for postmenopausal symptoms.

Acute effects of (-)-gallocatechin gallate-rich green tea extract on the cerebral hemodynamic response of the prefrontal cortex in healthy humans

Objective

The benefits of long-term consumption of green tea on the brain are well known. However, among many ingredients of green tea, the acute effects of (-)-gallocatechin gallate-rich green tea extract (GCG-GTE), have received comparatively less attention. Herein, we investigated the acute effects of oral ingestion of green tea with GCG-GTE, which contains close replicas of the ingredients of hot green tea, on task-dependent hemodynamics in the prefrontal cortex of healthy adult human brains.

Methods

In this randomized, double-blind, placebo-controlled, parallel group trial, 35 healthy adults completed computerized cognitive tasks that demand activation of the prefrontal cortex at baseline and 1 h after consumption of placebo and 900 mg of GCG-GTE extract supplement. During cognitive testing, hemodynamic responses (change in HbO2 concentration) in the prefrontal cortex were assessed using functional near-infrared spectroscopy (fNIRS).

Results

In fNIRS data, significant group x session interactions were found in the left (p = 0.035) and right (p = 0.036) dorsolateral prefrontal cortex (DLPFC). In behavioral data, despite the numerical increase in the GCG-GTE group and the numerical decrease in the Placebo group, no significant differences were observed in the cognitive performance measure between the groups.

Conclusion

The result suggests a single dose of orally administered GCG-GTE can reduce DLPFC activation in healthy humans even with increased task demand. GCG-GTE is a promising functional material that can affect neural efficiency to lower mental workload during cognitively demanding tasks. However, further studies are needed to verify this.

Therapeutic actions of tea phenolic compounds against oxidative stress and inflammation as central mediators in the development and progression of health problems: A review focusing on microRNA regulation

Many health problems including chronic diseases are closely associated with oxidative stress and inflammation. Tea has abundant phenolic compounds with various health benefits including antioxidant and anti-inflammatory properties. This review focuses on the present understanding of the impact of tea phenolic compounds on the expression of miRNAs, and elucidates the biochemical and molecular mechanisms underlying the transcriptional and post-transcriptional protective actions of tea phenolic compounds against oxidative stress- and/or inflammation-mediated diseases. Clinical studies showed that drinking tea or taking catechin supplement on a daily basis promoted the endogenous antioxidant defense system of the body while inhibiting inflammatory factors. The regulation of chronic diseases based on epigenetic mechanisms, and the epigenetic-based therapies involving different tea phenolic compounds, have been insufficiently studied. The molecular mechanisms and application strategies of miR-27 and miR-34 involved in oxidative stress response and miR-126 and miR-146 involved in inflammation process were preliminarily investigated. Some emerging evidence suggests that tea phenolic compounds may promote epigenetic changes, involving non-coding RNA regulation, DNA methylation, histone modification, ubiquitin and SUMO modifications. However, epigenetic mechanisms and epigenetic-based disease therapies involving phenolic compounds from different teas, and the potential cross-talks among the epigenetic events, remain understudied.

Translationally controlled tumor protein restores impaired memory and altered synaptic protein expression in animal models of dementia

This study describes the effects of translationally controlled tumor protein (TCTP) on mice with memory impairment caused by scopolamine (SCO) administration. Specifically, memory functions and expression levels of hippocampal synaptic proteins in 7- to 12-month-old SCO-treated wild-type (WT-SCO) mice were compared to those of TCTP-overexpressing (TG) and TCTP knocked-down (KD) mice similarly treated with SCO. Passive-avoidance tasks were performed with WT, TG, and KD mice for four weeks after intraperitoneal injection of SCO or saline followed by an acquisition test. After completing behavioral studies, hippocampi of all mice groups were collected and their synaptic protein contents were subjected to Western blotting or immunohistochemical analyses, and compared with those of 5x familial Alzheimer's disease (5xFAD) mice and postmortem AD patients. Results of passive avoidance tests revealed that SCO-induced memory impairment was repaired in TCTP-TG mice, but not in TCTP-KD mice. Hippocampal expression levels of synaptophysin, synapsin-1, and PSD-95 were increased in TCTP-TG mice treated with SCO (TG-SCO) but decreased in TCTP-KD mice treated with SCO (KD-SCO). Decreased levels of TCTP, synaptophysin, and PSD-95 were also found in hippocampi of 5xFAD mice and AD patients. Expression levels of p-CREB/CREB and brain-derived neurotrophic factor (BDNF) in TCTP-TG and TG-SCO mice were similar to or increased compared to those in WT mice, but decreased in TCTP-KD and KD-SCO mice. BDNF immunoreactivity was restored in CA1 regions of hippocampi of TG-SCO mice, but not in KD-SCO mice. These results suggest that TCTP can restore damaged memory in mice possibly through restored synaptic protein expression.

Potential Alzheimer's disease therapeutic nano-platform: Discovery of amyloid-beta plaque disaggregating agent and brain-targeted delivery system using porous silicon nanoparticles

There has been a lot of basic and clinical research on Alzheimer's disease (AD) over the last 100 years, but its mechanisms and treatments have not been fully clarified. Despite some controversies, the amyloid-beta hypothesis is one of the most widely accepted causes of AD. In this study, we disclose a new amyloid-beta plaque disaggregating agent and an AD brain-targeted delivery system using porous silicon nanoparticles (pSiNPs) as a therapeutic nano-platform to overcome AD. We hypothesized that the negatively charged sulfonic acid functional group could disaggregate plaques and construct a chemical library. As a result of the in vitro assay of amyloid plaques and library screening, we confirmed that 6-amino-2-naphthalenesulfonic acid (ANA) showed the highest efficacy for plaque disaggregation as a hit compound. To confirm the targeted delivery of ANA to the AD brain, a nano-platform was created using porous silicon nanoparticles (pSiNPs) with ANA loaded into the pore of pSiNPs and biotin-polyethylene glycol (PEG) surface functionalization. The resulting nano-formulation, named Biotin-CaCl2-ANA-pSiNPs (BCAP), delivered a large amount of ANA to the AD brain and ameliorated memory impairment of the AD mouse model through the disaggregation of amyloid plaques in the brain. This study presents a new bioactive small molecule for amyloid plaque disaggregation and its promising therapeutic nano-platform for AD brain-targeted delivery.

Euonymus alatus Twig Extract Protects against Scopolamine-Induced Changes in Brain and Brain-Derived Cells via Cholinergic and BDNF Pathways

In the current study, the therapeutic and preventive effects of Euonymus alatus (EA) twig extract were investigated in a mouse model of cognitive deficit and B35 cells. Twig extract 1 was extracted with 70% ethanol and later twig extract 2 was extracted through liquid-liquid extraction with 70% ethanol and hexane. EA twig 2 (300 mg/kg) along with the standard drug donepezil (5 mg/kg) were orally administered to the mice for 34 days. Scopolamine was given intraperitoneally for 7 days. Administration of EA twig extract 2 significantly improved the passive avoidance test (PAT) in mice. EA twigs extract also restored the scopolamine-reduced brain-derived neurotrophic factor (BDNF)/extracellular regulated kinase (ERK)/cyclic AMP responsive element binding protein (CREB) signaling in B35 cells and the mouse hippocampus. In addition, EA twig extract significantly inhibited the acetylcholine esterase (AChE) activity in B35 cells in a dose-dependent manner. Chromatography and ESI MS analysis of EA twig extract revealed the presence of flavonoids; epicatechin, taxifolin, aromadendrin, and naringenin with catechin being the most abundant. These flavonoids exerted protective effects alone and had the possibility of synergistic effects in combination. Our work unmasks the ameliorating effect of EA twig extract 2 on scopolamine-associated cognitive impairments through the restoration of cholinergic systems and the BDNF/ERK/CREB pathway.

New Perspectives on Sleep Regulation by Tea: Harmonizing Pathological Sleep and Energy Balance under Stress

Sleep, a conservative evolutionary behavior of organisms to adapt to changes in the external environment, is divided into natural sleep, in a healthy state, and sickness sleep, which occurs in stressful environments or during illness. Sickness sleep plays an important role in maintaining energy homeostasis under an injury and promoting physical recovery. Tea, a popular phytochemical-rich beverage, has multiple health benefits, including lowering stress and regulating energy metabolism and natural sleep. However, the role of tea in regulating sickness sleep has received little attention. The mechanism underlying tea regulation of sickness sleep and its association with the maintenance of energy homeostasis in injured organisms remains to be elucidated. This review examines the current research on the effect of tea on sleep regulation, focusing on the function of tea in modulating energy homeostasis through sickness sleep, energy metabolism, and damage repair in model organisms. The potential mechanisms underlying tea in regulating sickness sleep are further suggested. Based on the biohomology of sleep regulation, this review provides novel insights into the role of tea in sleep regulation and a new perspective on the potential role of tea in restoring homeostasis from diseases.

Anti-obesity effects of heat-transformed green tea extract through the activation of adipose tissue thermogenesis

Background

Adipose tissue thermogenesis is a potential therapeutic target to increase energy expenditure and thereby combat obesity. The aim of the present study was to investigate the thermogenic and anti-obesity effects of heat-transformed green tea extract (HTGT) and enzymatically modified isoquercetin (EMIQ).

Methods

Immortalized brown pre-adipocytes and C3H10T1/2 cells were used for in vitro analyses. A high-fat diet (HFD)-induced obesity mouse model and CIDEA-reporter mice were used for in vivo experiments. The effects of HTGT and EMIQ on mitochondrial metabolism were evaluated by immunoblot, mitochondrial staining, and oxygen consumption rate analyses. In vivo anti-obesity effects of HTGT and EMIQ were measured using indirect calorimetry, body composition analyses, glucose tolerance tests, and histochemical analyses.

Results

Co-treatment with HTGT and EMIQ (50 μg/mL each) for 48 h increased brown adipocyte marker and mitochondrial protein levels (UCP1 and COXIV) in brown adipocytes by 2.9-fold, while the maximal and basal oxygen consumption rates increased by 1.57- and 1.39-fold, respectively. Consistently, HTGT and EMIQ treatment increased the fluorescence intensity of mitochondrial staining in C3H10T1/2 adipocytes by 1.68-fold. The combination of HTGT and EMIQ (100 mg/kg each) increased the expression levels of brown adipocyte markers and mitochondrial proteins in adipose tissue. Two weeks of HTGT and EMIQ treatment (100 mg/kg each) led to a loss of 3% body weight and 7.09% of body fat. Furthermore, the treatment increased energy expenditure by 8.95% and improved glucose tolerance in HFD-fed mice.

Conclusions

The current study demonstrated that HTGT and EMIQ have in vivo anti-obesity effects partly by increasing mitochondrial metabolism in adipocytes. Our findings suggest that a combination of HTGT and EMIQ is a promising therapeutic agent for the treatment of obesity and related metabolic diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00648-6.

Sea Cucumber-Derived Peptide Attenuates Scopolamine-Induced Cognitive Impairment by Preventing Hippocampal Cholinergic Dysfunction and Neuronal Cell Death

The incidence of neurodegenerative diseases related to cognitive decline and memory loss is on the rise as the global elderly population increases. In this study, we evaluated the effect of the sea cucumber-derived peptide Phe-Tyr-Asp-Trp-Pro-Lys (FYDWPK) on scopolamine-induced neurotoxicity in an animal model. The Morris water maze, passive avoidance apparatus, and shuttle box test were used to assess learning and memory abilities. In behavioral tests, FYDWPK effectively alleviated learning and memory impairment. FYDWPK also alleviated cholinergic dysfunction in mice with dementia. Furthermore, FYDWPK significantly improved oxidative imbalance by increasing superoxide dismutase activity and decreasing malondialdehyde levels (P < 0.05). The pathological results showed that FYDWPK alleviated neuronal loss, blurred caryotheca, and pyknotic nuclei in the hippocampus, and a high dose of FYDWPK had the best effect. In conclusion, FYDWPK alleviated cognitive and memory impairments by regulating oxidative imbalance, reducing cholinergic dysfunction, and relieving pathological alterations.

Ginsenoside Rg1 alleviates Aβ deposition by inhibiting NADPH oxidase 2 activation in APP/PS1 mice

Background

Ginsenoside Rg1 (Rg1), an active ingredient in ginseng, may be a potential agent for the treatment of Alzheimer’s disease (AD). However, the protective effect of Rg1 on neurodegeneration in AD and its mechanism of action are still incompletely understood.

Methods

Wild type (WT) and APP/PS1 AD mice, from 6 to 9 months old, were used in the experiment. The open field test (OFT) and Morris water maze (MWM) were used to detect behavioral changes. Neuronal damage was assessed by hematoxylin and eosin (H&E) and Nissl staining. Immunofluorescence, western blotting, and quantitative real-time polymerase chain reaction (q-PCR) were used to examine postsynaptic density 95 (PSD95) expression, amyloid beta (Aβ) deposition, Tau and phosphorylated Tau (p-Tau) expression, reactive oxygen species (ROS) production, and NAPDH oxidase 2 (NOX2) expression.

Results

Rg1 treatment for 12 weeks significantly ameliorated cognitive impairments and neuronal damage and decreased the p-Tau level, amyloid precursor protein (APP) expression, and Aβ generation in APP/PS1 mice. Meanwhile, Rg1 treatment significantly decreased the ROS level and NOX2 expression in the hippocampus and cortex of APP/PS1 mice.

Conclusions

Rg1 alleviates cognitive impairments, neuronal damage, and reduce Aβ deposition by inhibiting NOX2 activation in APP/PS1 mice.

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Rg1 treatment significantly alleviated cognitive dysfunction and neuronal damage in APP/PS1 mice.

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Rg1 treatment significantly reduced APP expression and Aβ deposition in APP/PS1 mice.

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The expression of NOX2 and ROS production were significantly increased in APP/PS1 mice.

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Rg1 treatment significantly decreased NOX2 expression and ROS accumulation in APP/PS1 mice.

The beneficial effects of green tea on sleep deprivation-induced cognitive deficits in rats: the involvement of hippocampal antioxidant defense

BACKGROUND

The weight of evidence suggests that sleep is essential for the processes of memory consolidation and sleep deprivation (SD) impairs the retention of long-term memory in both humans and experimental animals, which is associated with oxidative stress damage within the brain. Green tea polyphenols have revealed carcinogenic, antioxidant, anti-, and anti-mutagenic properties. We aimed to investigate the possible protective effect of green tea extract (GTE) and its main active catechin, epigallocatechin-3-gallate (EGCG), on post-training total sleep deprivation (TSD) -induced spatial memory deficits and oxidative stress profile in the hippocampus of the rat.

METHODS

Male rats were treated with saline, GTE (100 and 200 mg/kg/day), and EGCG (50 mg/kg/day) intraperitoneally for 21 days and then trained in Morris water maze (MWM) in a single day protocol. Immediately after the end of MWM training, animals were sleep deprived for 6 h by the gentle handling method, and then evaluated for spatial memory. Hippocampal levels of malondialdehyde, (MDA), and thiol was assessed as oxidant and antioxidant markers.

RESULTS

Spatial memory was impaired in the TSD group and GTE at the dose of 200 mg/kg/day as well as EGCG at the dose of 50 mg/kg/day could reverse the impairment to the saline-treated levels. Despite the unchanged MDA levels, hippocampal total thiol was significantly decreased after TSD and EGCG increased it to the basal levels.

CONCLUSION

In conclusion, green tea and its main catechin, EGCG, could prevent memory impairments during 6 h of TSD; probably through normalizing the antioxidant thiol defense system which was impaired during TSD.

Impact of dietary polyphenols on neuroinflammation-associated disorders

Neurodegenerative disorders like Alzheimer's, Parkinson's, and associated dementia typically originate with altered protein folding and aggregation of their β structures in the neurons. This self-aggregation leads to glial activation in the brain, causing neuroinflammation and leads to neuronal death. According to statistics provided by WHO, there are around 50 million people with dementia worldwide and every year, 10 million more cases are projected to increase. Also, around 5-8 percentage of people who are aged above 60 globally has dementia or associated disorders. Over 82 million in 2030 and 152 in 2050 are expected to have dementia. Most of these patients fall into low-middle-income countries which makes it even more essential to find an affordable and effective treatment method. Polyphenols of different origin are studied for their potential role as anti-neuro-inflammatory molecules. This review would summarize recent advances in three widely researched dietary polyphenols projected as potential therapeutic agents for disorders like Alzheimer's, Parkinson's, etc. They are Resveratrol, Catechins, and Tannins. The review would discuss the recent advances and challenges in using these polyphenols using specific examples as potential therapeutic agents against neuroinflammation associated disorders. An abstract of neuroinflammation-associated events and the effects by selected polyphenols.

Enhanced Neuroprotective Effects of Epicatechin Gallate Encapsulated by Bovine Milk-Derived Exosomes against Parkinson's Disease through Antiapoptosis and Antimitophagy

Epicatechin gallate (ECG) is a main effective catechin widely existing in natural plants and food, with well-known health benefits. The present study first designed a new exosome-based delivery system for ECG and examined its neuroprotective effects on a rotenone (Rot)-induced Parkinson's disease (PD) model in vitro. Exosomes (Exo) were isolated from fresh bovine milk, and their average size was 85.15 ± 2.00 nm. ECG was encapsulated into Exo by a sonication method, and the loading efficiency of ECG-loaded exosomes (ECG-Exo) was 25.96 ± 0.45%. The neuroprotective effects of ECG-Exo were evaluated on Rot-induced SHSY5Y cells and compared with free ECG. Cell viability, cellular reactive oxygen species, apoptosis rate, and the expressions of caspase-3, Bax, Bcl-2, parkin, PINK1, and Atg5 were determined. Our results showed that Exo delivered ECG successfully into SHSY5Y cells and exhibited enhanced neuroprotective effects. ECG-Exo might inhibit SHSY5Y cell damage induced by Rot through antiapoptosis and antimitophagy.