Cognitive Enhancing Properties Research Articles

The role of chitosan in mitigating tert-butylhydroquinone induced cognitive impairment and neurotoxicity in a rat model.

This study aimed to investigate the impact of tert-butylhydroquinone (TBHQ), chitosan, and their combination on memory and neurobiochemical parameters in a rat model. The primary objectives were to assess the cognitive effects of TBHQ, explore the cognitive-enhancing properties of chitosan, and evaluate the combined effects of these substances. A rat model was employed for behavioral tests, biochemical analyses, and histological examinations. Rats were exposed to TBHQ, chitosan, or a combination of both, and cognitive function was assessed through behavioral tests. Biochemical analyses focused on neurobiochemical parameters associated with memory and oxidative stress. Histological examinations were conducted to observe any structural changes in the brain. TBHQ exposure was associated with memory impairments and increased oxidative stress, indicating potential neurotoxic effects. Chitosan supplementation demonstrated cognitive-enhancing effects and showed promise in mitigating the memory impairments and oxidative stress induced by TBHQ. The combination of chitosan and TBHQ presented a potential protective effect on neurological health. Chitosan supplementation alongside TBHQ may mitigate memory impairments and oxidative stress associated with TBHQ exposure in a rat model. The study provides valuable insights into the cognitive effects of TBHQ and the neuroprotective potential of chitosan, highlighting the need for further research to elucidate molecular pathways and clinical implications. These findings contribute to understanding chitosan's role in safeguarding neurological health in conditions where TBHQ exposure is a concern, warranting further investigations for translational applications in human health.

Ameliorative effect of β‐pinene targeting mitochondrial dysfunction and oxidative stress in Alzheimer’s disease

AbstractBackgroundSporadic Alzheimer’s disease (sAD) is the most common type of dementia, characterized by the deposition of extracellular senile plaques, neurofibrillary tangles (NFTs), and neurodegeneration, leading to memory impairment and dementia. Intracerebroventricular (ICV) streptozotocin (STZ) mimics sporadic Alzheimer’s disease (sAD) characterized by neurodegeneration arising from oxidative stress, and mitochondrial dysfunction. β‐pinene is a monoterpene having antioxidant properties interlinked with mitochondrial functioning. To study the neuroprotective and cognitive enhancement properties of β‐pinene on mitochondrial dysfunction, oxidative stress, and histological changes in an animal model of Alzheimer’s disease induced by ICV‐STZ.MethodTo establish the sAD model, intracerebroventricular (ICV) streptozotocin (STZ) at a dose of 3 mg/kg was administered bilaterally in rats on a stereotaxic apparatus. Behavioral tests such as Morris water maze (MWM), novel object recognition (NOR) and Actophotometer were performed to evaluate spatial & recognition memory and locomotor functions. Three treatment doses (50mg/kg, 100 mg/kg and 200mg/kg) of Beta pinene (β‐pinene) and Galantamine (2 mg/kg) as a reference drug were given orally to ICV‐STZ induced rats for 21 days. Cortical and hippocampal tissues were dissected. Estimation of oxidative stress, mitochondrial dysfunction as complex I, II, III, IV activity and acetylcholinesterase activity were performed for cholinergic function. Moreover, histopathology was evaluated by hematoxylin and eosin (H&E) staining.Resultβ‐pinene treatment attenuated ICV‐STZ‐induced cognitive impairment in MWM and NOR. There is no significant effect revealed on locomotor activities. Moreover, in the cortex and hippocampal area of the brain, Mitochondrial enzyme complex I, II, III, and IV, and acetylcholinesterase (AchE) activities were normalized. Furthermore, reduced glutathione (GSH), catalase, superoxide dismutase (SOD), and (Lipid peroxidation) LPO were also reversed. β‐pinene prevents neurodegeneration as examined in histopathology.ConclusionIn the ICV‐STZ rat model, β‐pinene was found to be neuroprotective by reducing oxidative stress and mitochondrial dysfunction, consequently enhancing cognitive functions indicated in the behavioral outcomes.

Evaluation of the cognitive enhancing properties of diosmin in lipopolysaccharide‐induced memory impairment in mice

AbstractBackgroundCognitive impairment is a major feature of many neurodegenerative disorders such as Alzheimer’s disease, dementia etc. The progressive cognitive decline in Alzheimer’s disease (AD) can be attributed to the fact that current anti‐Alzheimer’s drug only treat AD symptoms without completely reversing cognitive impairment in AD patients. Therefore, it is imperative to develop new therapeutic remedies that can improve memory and ameliorate cognitive impairment in AD patients. Disomin is a flavone with antioxidant, anti‐inflammatory and anti‐apoptotic properties. This study evaluated the neuroprotective effects of diosmin on LPS‐induced cognitive impairment in mice.MethodThirty‐six Swiss mice were randomly divided into six groups (n = 6). Group 1 received vehicle, group 2 received vehicle, groups 3 to 5 received diosmin (50, 100 and 200 mg/kg, p.o.) respectively group 6 received donepezil (50 mg/kg, p.o.). Sixty minutes after the treatment with the vehicle/Diosmin/Donepezil, lipopolysaccharide (LPS) (250ug/kg, i.p.) was administered daily to groups 2 to 6 for seven days. Twenty‐four hours after treatment on day 7, mice were subjected to Y‐maze test and the Novelty object recognition test (NORT) to assess their spatial and non‐spatial working memory. Subsequently, the mice were sacrificed and their brain samples were harvested for biochemical analysis (TNF‐alpha, Interferon gamma and interleukin‐12), immunohistochemical examinations (Amyloid beta, BDNF, IBA‐1, NLRP3 expression) and Golgi staining procedure for morphological alterations.ResultOur data shows that diosmin increased percentage alternation in Y‐maze test and discrimination ratio in NORT compared with the control group. Diosmin significantly (p<0.05) decreased TNF‐alpha, Interferon gamma and interleukin‐12 and reduced neurodegeneration in the CA1 region of the hippocampus & dendate gyrus when compared with the control group.ConclusionDiosmin reversed LPS‐induced cognitive impairment, which can be attributed to its neuroprotective and anti‐inflammatory properties.

Neuroprotective Effect of Natural Indole and β-carboline Alkaloids against Parkinson's Disease: An Overview.

Parkinson's disease (PD) is a devastating neurodegenerative condition that mostly damages dopaminergic neurons in the substantia nigra and impairs human motor function. Males are more likely than females to have PD. There are two main pathways associated with PD: one involves the misfolding of α-synuclein, which causes neurodegeneration, and the other is the catalytic oxidation of dopamine via MAO-B, which produces hydrogen peroxide that can cause mitochondrial damage. Parkin (PRKN), α-synuclein (SNCA), heat shock protein (HSP), and leucine-rich repeat kinase-2 (LRRK2) are some of the target areas for genetic alterations that cause neurodegeneration in Parkinson's disease (PD). Under the impact of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which is also important in Parkinson's disease (PD), inhibition of mitochondrial complex 1 results in enhanced ROS generation in neuronal cells. Natural products are still a superior option in the age of synthetic pharmaceuticals because of their lower toxicity and moderate side effects. A promising treatment for PD has been discovered using beta-carboline (also known as " β-carboline") and indole alkaloids. However, there are not many studies done on this particular topic. In the herbs containing β-carbolines and indoles, the secondary metabolites and alkaloids, β-carbolines and indoles, have shown neuroprotective and cognitive-enhancing properties. In this review, we have presented results from 18 years of research on the effects of indole and β-carboline alkaloids against oxidative stress and MAO inhibition, two key targets in PD. In the SAR analysis, the activity has been correlated with their unique structural characteristics. This study will undoubtedly aid researchers in looking for new PD treatment options.

Cognitive enhancing properties of aqueous leaf extract of Vigna unguiculata in ketamine-induced memory damage in mice

Conventional remedies for management of Alzheimer’s disease (AD) and related cognitive deficits are not curative but relieves the symptoms and they cause adverse side effects. Alternatively, use of herbal therapies to manage cognitive illnesses has increased substantially. Vigna unguiculata is commonly utilized for nutritional benefits and management of neurological disorders in herbal medicine. The present study evaluated cognitive enhancing potential of V. unguiculata leaf aqueous extract in mice with ketamine-induced AD-like cognitive deficits. Cognitive performance indicated by step-through latency was assessed using passive avoidance test. Anti-acetylcholinesterase (anti-AChE) and antioxidant potential of the extract was assessed using brains of the test animals. Further, phytochemical constituents of the extracts were determined using LC-MS. Aqueous extract of V. unguiculata leaf demonstrated significant prowess to combat cognitive deficits in the test animals. This was evidenced by significantly higher (p < 0.001) step-through latencies in extract-treated mice than the untreated cognitively damaged mice. Moreover, cognitively damaged mice given the studied extract exhibited significantly less (p < 0.001) malondialdehyde levels and acetylcholinesterase activity than the negative control mice. This result confirmed antioxidant and anti-AChE properties of V. unguiculata, indicating its potential to attenuate oxidative stress in the brain and augment cholinergic transmission. Notably, some conventional therapies for cognitive disorders especially AD are AChE inhibitors. The studied extract contained phytocompounds such as flavonoids and phenolics with confirmed antioxidant and anti-AChE activities, thus, its cognitive enhancing efficacy could be attributed to these phytoconstituents. Collectively, this study upholds V. ungiculata usefulness in management of cognitive illnesses.

Evaluation of the Effect of Cariprazine on Memory and Cognition in Experimental Rodent Models.

The main symptoms of schizophrenia are categorized as positive, negative, and cognitive. Cognitive impairments do not generally respond to antipsychotics. Cariprazine is a novel antipsychotic conceived with the idea that high affinity for D3 receptors may elicit a favorable response in the management of cognitive deficits. We evaluated the pro-cognitive properties of 14-day long pre-treatment with cariprazine (0.25, 0.5, and 1 mg/kg b.w. intraperitoneally) in experimental rodent models with scopolamine-induced memory impairment employing novel object recognition test (NORT), T-maze, Y-maze, and passive avoidance tasks (step-through and step-down). Statistical analysis was performed with One Way ANOVA. In NORT cariprazine increased the recognition index. In T-maze and Y-maze cariprazine increased the working memory index as well as the percentage of spontaneous alternation. Cariprazine improved learning and memory in both short-term and long-term memory retention tests in step-down and step-through tasks. Cariprazine improves learning, recognition, and spatial memory in rats with scopolamine-induced memory impairment. Cariprazine's beneficial effect on cognition is likely due to its affinity for D3 receptors, as well as agonism at 5-HT1A receptors. Most probably, the cognitive-enhancing properties of cariprazine are the result of integrated modulation in the amygdala, hippocampus, and prefrontal cortex.

Design, synthesis and biological evaluation of pyranocarbazole derivatives against Alzheimer’s disease, with antioxidant, neuroprotective and cognition enhancing properties

A series of novel pyranocarbazole alkaloids were designed and synthesized as derivatives of Claulansine F and CZ-7. Some of the compounds showed strong neuroprotective effects and anti-lipid peroxidation capacity. Among these compounds, 10b, introduced leucine at the C-3 position of pyranocarbazole, was the most active in inhibiting the programmed death of SH-SY5Y cells. This compound exhibited stronger free radical scavenging activity than Edaravone. Furthermore, 10b could penetrate the blood–brain barrier (BBB). More importantly, 10b showed a tendency of improvement in learning and memory in the dose range of 10–40 mg/kg. The research on mechanisms indicated that 10b could reduce oxidative stress in the brain of Aβ25-35-intoxicated mice, and then improve the cognitive function of Aβ25-35-intoxicated mice. Our findings suggest that 10b may be promising for further evaluation as an intervention for Alzheimer’s Disease.

Agmatine improves olfactory and cognitive deficits in Spontaneously Hypertensive Rats (SHR): An animal model of Attention Deficit Hyperactivity Disorder (ADHD).

Attention Deficit Hyperactivity Disorder (ADHD) is a highly prevalent and disabling disorder that frequently persists into adulthood. Many patients are considered nonresponders to typical pharmacological treatments due to insufficient symptoms' reduction or the inability to tolerate the side effects of these medications. Agmatine is an endogenous neuromodulator with emotional- and cognitive-enhancing properties that arises as a promising agent to manage several Central Nervous System disorders. Here, we investigated the effects of chronic treatment with agmatine on behavioral impairments exhibited by adult Spontaneously Hypertensive Rats (SHR), an animal model for the study of ADHD. Adult male Wistar and SHR (3-4 months old) received intraperitoneal (i.p.) treatment with saline (NaCl 0.9%) or agmatine (30 mg/kg/day) during 20 consecutive days and were evaluated in a battery of behavioral tasks. Agmatine treatment improved olfactory and recognition memory impairments of SHR evaluated in the olfactory discrimination, object recognition, and social recognition memory tasks. In addition, agmatine administration improved the cognitive flexibility in the water maze test. Agmatine did not alter SHR's locomotor activity and hedonic-like behaviors observed in the open-field and splash tests, respectively. No changes were observed in SHR's systolic blood pressure following agmatine treatment. This study provides the first evidence that agmatine improves olfactory and cognitive impairments observed in an animal model of ADHD. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Azepine-Indole Alkaloids From Psychotria nemorosa Modulate 5-HT2A Receptors and Prevent in vivo Protein Toxicity in Transgenic Caenorhabditis elegans.

Nemorosine A (1) and fargesine (2), the main azepine-indole alkaloids of Psychotria nemorosa, were explored for their pharmacological profile on neurodegenerative disorders (NDs) applying a combined in silico–in vitro–in vivo approach. By using 1 and 2 as queries for similarity-based searches of the ChEMBL database, structurally related compounds were identified to modulate the 5-HT2A receptor; in vitro experiments confirmed an agonistic effect for 1 and 2 (24 and 36% at 10 μM, respectively), which might be linked to cognition-enhancing properties. This and the previously reported target profile of 1 and 2, which also includes BuChE and MAO-A inhibition, prompted the evaluation of these compounds in several Caenorhabditis elegans models linked to 5-HT modulation and proteotoxicity. On C. elegans transgenic strain CL4659, which expresses amyloid beta (Aβ) in muscle cells leading to a phenotypic paralysis, 1 and 2 reduced Aβ proteotoxicity by reducing the percentage of paralyzed worms to 51%. Treatment of the NL5901 strain, in which α-synuclein is yellow fluorescent protein (YFP)-tagged, with 1 and 2 (10 μM) significantly reduced the α-synuclein expression. Both alkaloids were further able to significantly extend the time of metallothionein induction, which is associated with reduced neurodegeneration of aged brain tissue. These results add to the multitarget profiles of 1 and 2 and corroborate their potential in the treatment of NDs.

The Relationship Between Cannabis, Cognition, and Schizophrenia: It's Complicated.

The consequences of cannabis use, especially in the context of schizophrenia, have gained increased importance with the legalization of cannabis in North America and across the globe. Cannabis use has multifaceted impacts on cognition in schizophrenia patients and healthy subjects. Healthy subjects, particularly those who initiated cannabis use at earlier ages and used high-potency cannabis for longer durations, exhibited poorer cognition mainly in working memory and attention. Cannabis use in schizophrenia has been associated with symptom exacerbation, longer and more frequent psychotic episodes, and poorer treatment outcomes. However, cannabis-using patients have better overall cognitive performance compared to patients who were not cannabis users. Interestingly, these effects were only apparent in lifetime cannabis users, but not in current (or within last 6months) users. Moreover, higher frequency and earlier age of cannabis use initiation (i.e., before 17years of age) were associated with better cognitive performance, although they had an earlier illness onset. Three possible hypotheses seem to come forward to explain this paradox. First, some components of cannabis may have antipsychotic or cognitive-enhancing properties. Secondly, chronic cannabis use may alter endocannabinoid signaling in the brain which could be a protective factor for developing psychosis or cognitive impairments. A third explanation could be their representation of a phenotypically distinct patient group with more intact cognitive functioning and less neurodevelopmental pathology. Multiple factors need to be considered to understand the complex relationship between cannabis, cognitive function, and schizophrenia. In short, age at initiation, duration and rate of cannabis use, abstinence duration, co-use of substances and alcohol, prescribed medications, relative cannabinoid composition and potency of cannabis, presence of genetic and environmental vulnerability factors are prominent contributorsto the variability in outcomes. Animal studies support the disruptive effects of Δ9-tetrahydrocannabinol (THC) administration during adolescence on attention and memory performance. They provide insights about interaction of cannabinoid receptors with other neurotransmitter systems, such as GABA and glutamate, and other regulatory molecules, such as PSD95 and synaptophysin. Cannabidiol (CBD), on the other hand, can improve cognitive deficits seen in neurodevelopmental and chemically-induced animal models of schizophrenia. Future studies focusing on bridging the translational gaps between human and animal studies, through the use of translationally relevant methods of exposure (e.g., vaping), consistent behavioral assessments, and congruent circuit interrogations (e.g., imaging) will help to further clarify this complex picture.

A novel neuroprotective cholinesterase-monoamine oxidase inhibitor for treatment of dementia and depression in Parkinson’s disease

The current novel therapeutic approach suggests that multi-targeted compounds, with diverse biological activities but a single set of bioavailability and pharmacokinetics, will be significantly more advantageous in the treatment of the complex pathology of Parkinson’s diseases (PD) than traditional therapies. This review introduces a novel cholinesterase (ChE)-monoamine oxidase (MAO) inhibitor, namely MT-031, which was designed by amalgamating the propargyl moiety of the irreversible selective MAO-B inhibitor and neuroprotective/neurorestorative anti-Parkinsonian drug, rasagiline, into the methylamino position of the ChE inhibitor anti-AD drug, rivastigmine. MT-031 possesses neuroprotective, cognition enhancing, anti-depressant, and anti-inflammatory properties both in vitro and in vivo. Altogether, these findings suggest that MT-031 may be a potential treatment for combating PD and associated dementia and depression.

The Impact of Medium Chain and Polyunsaturated ω-3-Fatty Acids on Amyloid-β Deposition, Oxidative Stress and Metabolic Dysfunction Associated with Alzheimer's Disease.

Alzheimer’s disease (AD), the most common cause of dementia in the elderly population, is closely linked to a dysregulated cerebral lipid homeostasis and particular changes in brain fatty acid (FA) composition. The abnormal extracellular accumulation and deposition of the peptide amyloid-β (Aβ) is considered as an early toxic event in AD pathogenesis, which initiates a series of events leading to neuronal dysfunction and death. These include the induction of neuroinflammation and oxidative stress, the disruption of calcium homeostasis and membrane integrity, an impairment of cerebral energy metabolism, as well as synaptic and mitochondrial dysfunction. Dietary medium chain fatty acids (MCFAs) and polyunsaturated ω-3-fatty acids (ω-3-PUFAs) seem to be valuable for disease modification. Both classes of FAs have neuronal health-promoting and cognition-enhancing properties and might be of benefit for patients suffering from mild cognitive impairment (MCI) and AD. This review summarizes the current knowledge about the molecular mechanisms by which MCFAs and ω-3-PUFAs reduce the cerebral Aβ deposition, improve brain energy metabolism, and lessen oxidative stress levels.

Ultrasound assisted extraction and quantification of targeted bioactive compounds of Centella asiatica (Gotu Kola) by UHPLC-MS/MS MRM tandem mass spectroscopy

Centella asiatica (Gotu Kola) is a green leafy vegetable rich in phytochemicals mainly including triterpenes and caffeoylquinic acids. Fresh leaves of this plant are consumed in salads and beverages in a variety of cuisines around the world. This is a well-known functional food for its neuroprotective and cognition enhancing properties in traditional societies.HPLC-DAD at lower wavelengths commonly used to identify and quantify major triterpenes of C. asiatica extracts, but associated with few drawbacks. This paper discusses a specific, sensitive and validated method developed based on UHPLC-ESI-MS-MS-MRM tandem mass spectroscopy for targeted quantification of C. asiatica bioactive compounds.The validated method enabled a precise estimation of major triterpenes and chlorogenic acid in C. asiatica in a shorter time. The findings of this study will contribute to the information on chemotype variation of C. asiatica plant grown under unique geographical, environmental and climatic conditions in New Zealand.

Long-term running exercise alleviates cognitive dysfunction in APP/PSEN1 transgenic mice via enhancing brain lysosomal function.

Amyloid-β peptide (Aβ) aggregation is the hallmark of Alzheimer's disease (AD). The imbalance between the production and clearance of Aβ results in the accumulation and aggregation of Aβ in the brain. Thus far, few drugs are available for AD treatment, but exercise has been recognized for its cognition-enhancing properties in AD patients. The underlying mechanisms remain unclear. Our recent study showed that long-term running exercise could activate the lysosomal function in the brains of mice. In this study, we investigated whether exercise could reduce Aβ accumulation by activating lysosomal function in APP/PSEN1 transgenic mice. Started at the age of 5 months, the mice were trained with a running wheel at the speed of 18 r/min, 40 min/d, 6 d/week for 5 months, and were killed at the end of the 10th month, then brain tissue was collected for biochemical analyses. The cognitive ability was assessed in the 9th month. We showed that long-term exercise significantly mitigated cognitive dysfunction in AD mice, accompanied by the enhanced lysosomal function and the clearance of Aβ in the brain. Exercise significantly promoted the nuclear translocation of transcription factor EB (TFEB), and increased the interaction between nuclear TFEB with AMPK-mediated acetyl-CoA synthetase 2, thus enhancing transcription of the genes associated with the biogenesis of lysosomes. Exercise also raised the levels of mature cathepsin D and cathepsin L, suggesting that more Aβ peptides could be degraded in the activated lysosomes. This study demonstrates that exercise may improve the cognitive dysfunction of AD by enhancing lysosomal function.

Exploiting the neuroprotective effects of α-klotho to tackle ageing- and neurodegeneration-related cognitive dysfunction.

Cognitive dysfunction is a key symptom of ageing and neurodegenerative disorders, such as Alzheimer’s disease (AD). Strategies to enhance cognition would impact the quality of life for a significant proportion of the ageing population. The α-klotho protein may protect against cognitive decline through multiple mechanisms: such as promoting optimal synaptic function via activation of N-methyl-d-aspartate (NMDA) receptor signalling; stimulating the antioxidant defence system; reducing inflammation; promoting autophagy and enhancing clearance of amyloid-β. However, the molecular and cellular pathways by which α-klotho mediates these neuroprotective functions have yet to be fully elucidated. Key questions remain unanswered: which form of α-klotho (transmembrane, soluble or secreted) mediates its cognitive enhancing properties; what is the neuronal receptor for α-klotho and which signalling pathways are activated by α-klotho in the brain to enhance cognition; how does peripherally administered α-klotho mediate neuroprotection; and what is the molecular basis for the beneficial effect of the VS variant of α-klotho? In this review, we summarise the recent research on neuronal α-klotho and discuss how the neuroprotective properties of α-klotho could be exploited to tackle age- and neurodegeneration-associated cognitive dysfunction.

7,8-Dihydroxyflavone improves cognitive functions in ICV-STZ rat model of sporadic Alzheimer's disease by reversing oxidative stress, mitochondrial dysfunction, and insulin resistance.

Intracerebroventricular (ICV) streptozotocin (STZ) mimics sporadic Alzheimer's disease (SAD) characterized by tau pathology and neurodegeneration arising from oxidative stress, mitochondrial dysfunction, and insulin resistance. 7,8-Dihydroxyflavone (7,8-DHF) is a flavonoid having antioxidant property interlinked with mitochondrial functioning and insulin actions. To evaluate the neuroprotective and cognitive enhancement properties of 7,8-DHF in an ICV-STZ rat model of SAD. ICV-STZ (3 mg/kg) was injected into male Wistar rats. Cognitive functions were evaluated by Morris water maze (MWM) and novel object recognition (NOR). 7,8-DHF (5 mg/kg, 10 mg/kg, and 20 mg/kg) and rivastigmine (2 mg/kg) were given orally for 21 days. Reduced glutathione (GSH), catalase, superoxide dismutase (SOD), glutathione peroxidase (GPX), lipid peroxidation (LPO), protein carbonylation (PCO), and nitrite assays were performed. Mitochondrial enzyme complex I, II, III, and IV, and acetylcholinesterase (AchE) activities were determined. ELISA for the insulin-degrading enzyme (IDE) and p-tau was done. Histopathology was investigated by hematoxylin and eosin staining. 7,8-DHF treatment attenuated ICV-STZ-induced cognitive deficit in MWM and NOR. Moreover, in the cortex and hippocampus regions of the brain, GSH, catalase, SOD, GPX, LPO, PCO, and nitrite levels were reversed. Mitochondrial enzyme complex I, II, III, and IV, and acetylcholinesterase (AchE) activities were also normalized. IDE and p-tau protein were found to be significantly altered. 7,8-DHF provided protection from neuronal cell death examined in histopathology. Conclusively, 7,8-DHF was found to be neuroprotective in the ICV-STZ rat model by ameliorating oxidative stress, mitochondrial dysfunction, and insulin resistance, thereby improving cognitive functions evident with the behavioral results.

Alzheimer's disease: exploring nature's 'medicinal chest' for new therapeutic agents.

Natural products have served humanity as a valuable source for the discovery and development of therapeutic agents. In addition, these phytochemicals can function as lead compounds for the development of synthetic analogs aimed at treating human diseases. In our aging society, Alzheimer's disease (AD) is the most common cause of dementia, which is characterized by a significant and progressive loss of memory and other cognitive functions. As society demographics change, the predominance of AD and other age-related dementias is increasing, with concurrent financial and societal costs.AD represents one of the most remarkable scientific challenges for drug discovery as the search for effective disease-modifying agents has been unsuccessful. Medicinal plants have been used for their "anti-aging" properties, and cognitive enhancing properties. In the past decades, natural products have been studied for their anti-AD properties, and their potential for developing therapeutic agents against several molecular targets has been evaluated. This insight evaluates the prospects of medicinal plants for providing disease-modifying, as well as disease-preventing, agents for AD.

The Effects of a Functional Food Breakfast on Gluco-Regulation, Cognitive Performance, Mood, and Satiety in Adults.

A whole diet which combines multiple functional foods benefits metabolic risk factors and cognition, but evidence supporting meal to meal benefits, which individuals may find easier to implement, is limited. This study developed a functional food breakfast (FB), using polyphenol-rich ingredients selected for their gluco-regulating and cognitive-enhancing properties, and compared it to a control breakfast (CB). For study 1, total polyphenols were determined using the Folin–Ciocalteu method, and sugar release by in vitro digestion, in frozen and fresh samples. In study 2, healthy adults (n = 16) consumed an FB, CB and ready-to-eat breakfast cereal (RTEC) in a randomised crossover design. Glucose (GR) and insulin response (IR), satiety, mood and memory were measured over 180 min. The FB was a rich source of polyphenols (230 mg) compared to the CB (147 mg) (p < 0.05), and using frozen muffins did not compromise the polyphenol content or sugar release. Peak GR was highest after the RTEC (p < 0.05), and the insulin area under the curve (AUC) was lowest in the FB at 60, 120, 180 min and peak (p < 0.05). There were no effects on GR AUC, mood, satiety or memory. Reductions in GR peak and IR following consumption of the FB support the inclusion of functional ingredients at breakfast.

Baicalin Ameliorates Cognitive Impairment and Protects Microglia from LPS-Induced Neuroinflammation via the SIRT1/HMGB1 Pathway.

Systemic inflammation often induces neuroinflammation and disrupts neural functions, ultimately causing cognitive impairment. Furthermore, neuronal inflammation is the key cause of many neurological conditions. It is particularly important to develop effective neuroprotectants to prevent and control inflammatory brain diseases. Baicalin (BAI) has a wide variety of potent neuroprotective and cognitive enhancement properties in various models of neuronal injury through antioxidation, anti-inflammation, anti-apoptosis, and stimulating neurogenesis. Nevertheless, it remains unclear whether BAI can resolve neuroinflammation and cognitive decline triggered by systemic or distant inflammatory processes. In the present study, intraperitoneal lipopolysaccharide (LPS) administration was used to establish neuroinflammation to evaluate the potential neuroprotective and anti-inflammatory effects of BAI. Here, we report that BAI activated silent information regulator 1 (SIRT1) to deacetylate high-mobility group box 1 (HMGB1) protein in response to acute LPS-induced neuroinflammation and cognitive deficits. Furthermore, we demonstrated the anti-inflammatory and cognitive enhancement effects and the underlying molecular mechanisms of BAI in modulating microglial activation and systemic cytokine production, including tumor necrosis factor- (TNF-) α and interleukin- (IL-) 1β, after LPS exposure in mice and in the microglial cell line, BV2. In the hippocampus, BAI not only reduced reactive microglia and inflammatory cytokine production but also modulated SIRT1/HMGB1 signaling in microglia. Interestingly, pretreatment with SIRT1 inhibitor EX-527 abolished the beneficial effects of BAI against LPS exposure. Specifically, BAI treatment inhibited HMGB1 release via the SIRT1/HMGB1 pathway and reduced the nuclear translocation of HMGB1 in LPS-induced BV2 cells. These effects were reversed in BV2 cells by silencing endogenous SIRT1. Taken together, these findings indicated that BAI reduced microglia-associated neuroinflammation and improved acute neurocognitive deficits in LPS-induced mice via SIRT1-dependent downregulation of HMGB1, suggesting a possible novel protection against acute neurobehavioral deficits, such as delayed neurocognitive recovery after anesthesia and surgery challenges.

Neuroprotective expression of turmeric and curcumin

Turmeric (Curcuma longa) is extensively used as a spice and a coloring agent in Southeast Asia. Turmeric is used as a traditional remedy for cough, diabetic wounds, hepatic disorders, and rheumatism due to its antiseptic, antibacterial, and anti-inflammatory properties. Since the last few decades, extensive work has been done on turmeric and its constituents to explore its pharmacological actions. Curcumin is the main constituent of turmeric and is well demonstrated for its anti-inflammatory, hypoglycaemic, antioxidant, wound-healing, and antimicrobial activities. The functional neurons of the brain and synapses are lost in neurodegenerative disorders for which there is no permanent cure. Oxidative damage and inflammation play a role in age-related neurological disorders. The antioxidants have the ability to prevent different neurological disorders. Recent studies have shown that both turmeric and curcumin possess neuroprotective and cognitiveenhancing properties that help to prevent neurodegenerative diseases like Alzheimer's disease and Parkinson’s disease. Different experimental studies have indicated the antioxidant and anti-ageing properties of turmeric and curcumin. Various studies have shown that curcumin acts as a strong barrier against neurological disorders and, hence, it may be a potential drug candidate for the prevention of neurodegenerative diseases. The aim of this review was to present the current pieces of evidence in the literature regarding the neuroprotective effects of turmeric and curcumin.