Ginsenosides attenuate d-galactose- and AlCl3-inducedspatial memory impairment by restoring the dysfunction of the neurotransmitter systems in the rat model of Alzheimer's disease

Aluminum chloride and D-galactose induced a zebrafish model of Alzheimer's disease with cognitive deficits and aging

Alzheimer's disease (AD) is an age-related neurodegenerative disorder. Transgenic and pharmacological AD models are extensively studied to understand AD mechanisms and drug discovery. However, they are time-consuming and relatively costly, which hinders the discovery of potential anti-AD therapeutics. Here, we established a new model of AD in larval zebrafish by co-treatment with aluminum chloride (AlCl3) and D-galactose (D-gal) for 72 h. In particular, exposure to 150 μM AlCl3 + 40 mg/mL D-gal, 200 μM AlCl3 + 30 mg/mL D-gal, or 200 μM AlCl3 + 40 mg/mL D-gal successfully induced AD-like symptoms and aging features. Co-treatment with AlCl3 and D-gal caused significant learning and memory deficits, as well as impaired response ability and locomotor capacity in the plus-maze and light/dark test. Moreover, increased acetylcholinesterase and β-galactosidase activities, β-amyloid 1-42 deposition, reduced telomerase activity, elevated interleukin 1 beta mRNA expression, and enhanced reactive oxygen species production were also observed. In conclusion, our zebrafish model is simple, rapid, effective and affordable, incorporating key features of AD and aging, thus may become a unique and powerful tool for high-throughput screening of anti-AD compounds in vivo.

Fisetin-loaded pluronic-based nanogel: Radiation synthesis for alleviating neurocognitive impairments in a rat model of alzheimer's disease via modulation of the apoptotic cascade

Alzheimer's disease (AD) is a neurodegenerative disorder marked by cognitive impairment and memory loss. In this study, AD was experimentally induced in rats using aluminum chloride (AlCl3) and D-galactose (D-gal). Fisetin (Fis), a natural compound with antioxidant and anti-inflammatory properties, has potential for neurodegeneration management, but its low bioavailability limits clinical applications. To address this, we synthesized and characterized Pluronic-2-Acrylamido-2-methylpropane sulfonic acid (PLUR-PAMPS) nanogels using gamma radiation and successfully loaded Fis onto them (Fis-PLUR-PAMPS). The optimal formulation exhibited minimal particle size, a highly acceptable polydispersity index, and the highest zeta-potential, enhancing stability and solubilization efficiency. Our goal was to improve Fis's bioavailability and assess its efficacy against AlCl3/D-gal-induced AD. Male albino Wistar rats were pre-treated orally with Fis (40 mg/kg) or Fis-PLUR-PAMPS for seven days, followed by a seven-day intraperitoneal injection of AlCl3 and D-gal. Behavioral assessments, histopathological analysis, and biochemical evaluation of markers related to AD pathology were conducted. Results demonstrated that Fis-PLUR-PAMPS effectively mitigated cognitive impairments and neurodegenerative signs induced by AlCl3/D-gal. These findings suggest that Fis-PLUR-PAMPS nanogels enhance Fis's bioavailability and therapeutic efficacy, offering a promising approach for AD management.

Barbaloin's Chemical Intervention in Aluminum Chloride Induced Cognitive Deficits and Changes in Rats through Modulation of Oxidative Stress, Cytokines, and BDNF Expression

Alzheimer's disease (AD) is a long-term neurodegenerative condition characterized by impaired cognitive functions, particularly in the domains of learning and memory. Finding promising options for AD can be successful with a medication repurposing strategy. The goal of the research was to examine the neuroprotective characteristics of barbaloin in aluminum chloride (AlCl3)-induced cognitive deficits and changes in rats through modulation of oxidative stress, cytokines, and brain-derived neurotrophic factor (BDNF) expression. Thirty male Wistar rats were subjected to AlCl3 at a dosage of 100 mg/kg via the per oral route (p.o.), which induced cognitive decline. Morris water maze (MWM) is used to assess behavioral metrics. Assays for catalase (CAT), malondialdehyde (MDA), reduced glutathione (GSH), acetylcholinesterase (AChE), choline-acetyltransferase (ChAT), interleukins-1β (IL-1β), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), nuclear factor kappa-B (NF-κB), interleukins-6 (IL-6), BDNF, and neurotransmitter levels [dopamine (DA), acetylcholine (Ach), and γ-aminobutyric acid (GABA)] were performed. Results: The transfer latency time was notably decreased, and substantial modifications in the concentrations of GSH, MDA, CAT, SOD, AChE, ChAT and observed modulations in the formation of interleukins-6 (IL-6), TNF-α, IL-1β, BDNF, and NF-κB were also evidenced after the treatment of rats with barbaloin in comparison to AlCl3-induced control groups. Significant alterations in neurotransmitter levels (DA, Ach, and GABA) were also seen in barbaloin-treated groups in comparison to AlCl3-induced groups. The current investigation has provided evidence that the administration of barbaloin yielded notable enhancements in cognitive function in rats through the inhibition of MDA, enhancing endogenous antioxidant enzymes, reduction of cytokine levels, and enhancement of neurotransmitter contents in the brain. These effects were observed in comparison to a control group treated with AlCl3 and can be attributable to barbaloin's strong anti-inflammatory and antioxidant properties, and metal chelating properties may contribute to its neuroprotective effects. Barbaloin may also promote neuronal survival and enhance learning and memory by upregulating the expression of BDNF.

Effects of Red ginseng on neuroinflammation in neurodegenerative diseases

Red ginseng (RG) is widely used as a herbal medicine. As the human lifespan has increased, numerous diseases have developed, and RG has also been used to treat various diseases. Neurodegenerative diseases are major problems that modern people face through their lives. Neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis are featured by progressive nerve system damage. Recently, neuroinflammation has emerged as a degenerative factor and is an immune response in which cytokines with nerve cells that constitute the nervous system. RG, a natural herbal medicine with fewer side effects than chemically synthesized drugs, is currently in the spotlight. Therefore, we reviewed studies reporting the roles of RG in treating neuroinflammation and neurodegenerative diseases and found that RG might help alleviate neurodegenerative diseases by regulating neuroinflammation.

Active Compounds of Panax ginseng in the Improvement of Alzheimer's Disease and Application of Spatial Metabolomics

Panax ginseng C.A. Meyer (P. ginseng) is one of the more common traditional Chinese medicines (TCMs). It contains numerous chemical components and exhibits a range of pharmacological effects. An enormous burden is placed on people's health and life by Alzheimer's disease (AD), a neurodegenerative condition. Recent research has shown that P. ginseng's chemical constituents, particularly ginsenosides, have a significant beneficial impact on the prevention and management of neurological disorders. To understand the current status of research on P. ginseng to improve AD, this paper discusses the composition of P. ginseng, its mechanism of action, and its clinical application. The pathogenesis of AD includes amyloid beta protein (Aβ) generation and aggregation, tau protein hyperphosphorylation, oxidant stress, neuroinflammation, mitochondrial damage, and neurotransmitter and gut microbiota disorders. This review presents the key molecular mechanisms and signaling pathways of the active ingredients in P. ginseng involved in improving AD from the perspective of AD pathogenesis. A P. ginseng-related signaling pathway network was constructed to provide effective targets for the treatment of AD. In addition, the application of spatial metabolomics techniques in studying P. ginseng and AD is discussed. In summary, this paper discusses research perspectives for the study of P. ginseng in the treatment of AD, including a systematic and in-depth review of the mechanisms of action of the active substances in P. ginseng, and evaluates the feasibility of applying spatial metabolomics in the study of AD pathogenesis and pharmacological treatment.

Biotransformation of American Ginseng Stems and Leaves by an Endophytic Fungus Umbelopsis sp. and Its Effect on Alzheimer's Disease Control

BACKGROUND

Common ginsenosides can be transformed into rare ginsenosides through microbial fermentation, and some rare ginsenosides can prevent Alzheimer's disease (AD). This study aimed to transform common ginsenosides into rare ginsenosides through solid-state fermentation of American ginseng stems and leaves (AGSL) by an endophytic fungus and to explore whether fermented saponin extracts prevent AD.

METHODS

The powders of AGSL were fermented in a solid state by endophytic fungus. Total saponins were extracted from fermentation products using the methanol extraction method. The types of saponins were analyzed by liquid chromatography mass spectrometry (LC/MS). The Aβ42 concentration and β-secretase activity were measured by ELISA for the prevention of AD.

RESULTS

After AGSL was fermented by an endophytic fungus NSJG, the total saponin concentration of the fermented extract G-SL was higher than the unfermented CK-SL. Rare ginsenoside Rh1 was newly produced and the yield of compound K (561.79%), Rh2 (77.48%), and F2 (40.89%) was increased in G-SL. G-SL had a higher inhibition rate on Aβ42 concentration (42.75%) and β-secretase activity (42.22%) than CK-SL, possibly because the rare ginsenoside Rh1, Rh2, F2, and compound K included in it have a strong inhibitory effect on AD.

CONCLUSION

The fermented saponin extracts of AGSL show more inhibition effects on AD and may be promising therapeutic drugs or nutrients for AD.

Neuromodulatory effect of vardenafil on aluminium chloride/D-galactose induced Alzheimer's disease in rats: emphasis on amyloid-beta, p-tau, PI3K/Akt/p53 pathway, endoplasmic reticulum stress, and cellular senescence

Dysregulation of protein homeostasis, proteostasis, is a distinctive hallmark of many neurodegenerative disorders and aging. Deleteriously, the accumulation of aberrant proteins in Alzheimer's disease (AD) is accompanied with a marked collapse in proteostasis network. The current study explored the potential therapeutic effect of vardenafil (VAR), a phosphodiesterase-5 inhibitor, in AlCl3/D-galactose (D-gal)-induced AD in rats and its possible underlying mechanisms. The impact of VAR treatment on neurobehavioral function, hippocampal tissue architecture, and the activity of the cholinergic system main enzymes were assessed utilizing VAR at doses of 0.3 mg/kg and 1 mg/kg. Additionally, the expression level of amyloid-beta and phosphorylated tau proteins in the hippocampus were figured out. Accordingly, VAR higher dose was selected to contemplate the possible underlying mechanisms. Intriguingly, VAR elevated the cyclic guanosine monophosphate level in the hippocampus and averted the repressed proteasome activity by AlCl3/D-gal; hence, VAR might alleviate the burden of toxic protein aggregates in AD. In addition, a substantial reduction in the activating transcription factor 6-mediated endoplasmic reticulum stress was demonstrated with VAR treatment. Notably, VAR counteracted the AlCl3/D-gal-induced depletion of nuclear factor erythroid 2-related factor 2 level. Moreover, the anti-senescence activity of VAR was demonstrated via its ability to restore the balance of the redox circuit. The modulation of phosphatidylinositol-3-kinase/protein kinase B/p53 pathway and the reduction of nuclear factor kappa B level, the key regulator of senescence-associated secretory phenotype mediators release, with VAR treatment were also elucidated. Altogether, these findings insinuate the possible therapeutic benefits of VAR in AD management.

MemophenolTM Prevents Amyloid-β Deposition and Attenuates Inflammation and Oxidative Stress in the Brain of an Alzheimer's Disease Rat

Alzheimer's disease (AD) is the most common cause of dementia, and its prevalence rises with age. Inflammation and altered antioxidant systems play essential roles in the genesis of neurodegenerative diseases. In this work, we looked at the effects of Memophenol^TM, a compound rich in polyphenols derived from French grape (Vitis vinifera L.) and wild North American blueberry (Vaccinium angustifolium A.) extracts, in a rat model of AD. Methods: For 60 days, the animals were administered with AlCl₃ (100 mg/kg, orally) and D-galactose (60 mg/kg, intraperitoneally), while from day 30, Memophenol^TM (15 mg/kg) was supplied orally for 30 consecutive days. AlCl₃ accumulates mainly in the hippocampus, the main part of the brain involved in memory and learning. Behavioral tests were performed the day before the sacrifice when brains were collected for analysis. Results: Memophenol^TM decreased behavioral alterations and hippocampus neuronal degeneration. It also lowered phosphorylated Tau (p-Tau) levels, amyloid precursor protein (APP) overexpression, and β-amyloid (Aβ) buildup. Furthermore, Memophenol^TM reduced the pro-oxidative and pro-inflammatory hippocampus changes caused by AD. Our finding, relevant to AD pathogenesis and therapeutics, suggests that Memophenol^TM, by modulating oxidative and inflammatory pathways and by regulating cellular brain stress response mechanisms, protects against the behavioral and histopathological changes associated with AD.

The neuroprotective effect of ginsenoside Rb1 on the cerebral cortex changes induced by aluminium chloride in a mouse model of Alzheimer's disease: A histological, immunohistochemical, and biochemical study

Alzheimer's disease (AD) is one of the most common types of dementia among neurodegenerative disorders characterized by attention deficits and memory loss. Panax ginseng is a traditional Chinese herbal remedy that has been employed for millennia to manage dementia linked with aging and memory impairment. Ginsenoside Rb1 is one of Panax ginseng's most abundant components. The present work evaluated the neuroprotective effects of ginsenoside Rb1 on the cerebral cortex of AlCl₃-induced AD in adult male albino mice. Forty male mice were alienated arbitrarily into; control group, ginsenoside Rb1 group (70 mg/kg/day), AlCl₃ group (50 mg/kg/day), and ginsenoside Rb1-AlCl₃ group that received ginsenoside Rb1 one hour before AlCl₃. Oxidative stress parameters, Amyloid β (Aβ) and phosphorylated tau protein, and acetylcholine esterase (AChE) activity were measured. Cerebral cortex sections were evaluated histologically by light microscopic examination and immunohistochemistry. AlCl₃-induced memory impairment, Aβ and phosphorylated tau protein accumulation, and AChE elevation. Moreover, histopathological alterations in the cerebral cortex were reported in the form of irregular shrunken neurons and the surrounding neuropil showed vacuolation. Some neurons appeared with darkly stained nuclei, others had faintly stained ones. The synaptophysin expression was significantly decreased, while the expression of cleaved caspase-3, glial fibrillary acidic protein (GFAP), and ionized calcium-binding adaptor molecule 1 (Iba-1) were significantly elevated. It's interesting to note that these changes were attenuated in mice pretreated with ginsenoside Rb1. Collected data indicated that ginsenoside Rb1 showed a potential neuroprotective effect against cerebral cortex changes caused by AlCl₃ via suppression of Amyloid β and phosphorylated tau protein formation, oxidative stress correction, anti-apoptotic effect, and by minimizing gliosis.

Research progress in traditional Chinese medicine in the treatment of Alzheimer's disease and related dementias

Alzheimer's disease (AD) is the world's leading cause of dementia and has become a huge economic burden on nations and families. However, the exact etiology of AD is still unknown, and there are no efficient medicines or methods to prevent the deterioration of cognition. Traditional Chinese medicine (TCM) has made important contributions in the battle against AD based on the characteristics of multiple targets of TCM. This study reviewed the treatment strategies and new discoveries of traditional Chinese medicine in current research, which may be beneficial to new drug researchers.

Impact of ginseng on neurotoxicity induced by cisplatin in rats

Over the years, many researches have shown the potential protective effects of ginseng for preventing and treating neurological damage and their related diseases. Neuronal disturbance is one of the most common serious effects of cisplatin chemotherapy that triggers memory impairment and cognitive disability. Based on the hypothesis that mechanistic pathways of ginseng against the neurological and biochemical disturbance remain unclear, therefore, this study was designed to investigate the neuroprotective effect of ginseng extract against neurological and behavior abnormality induced by cisplatin in male rats. Animals were divided into 4 groups. Group 1 served as a control, group 2 was orally administrated with ginseng (100 mg/kg BW) daily for 90 days, group 3 was injected intraperitoneally with cisplatin (4 mg/kg BW) once a week for 90 days, and group 4 received ginseng and cisplatin. Cisplatin induced a learning and memory dysfunction in the Morris water maze task and locomotor disability in the rotarod test. In addition, cisplatin disrupted the oxidant/antioxidant systems, neuroinflammatory molecules (TNF-α, IL-6, IL-12, and IL-1β), neurotransmitters, and apoptotic (caspase-3, P53, and Bax) and dementia markers (amyloid-β40 and amyloid-β 42). Co-treatment with ginseng extracts successfully ameliorated the cognitive behaviors and intramuscular strength and presented a good protective agent against neurological damage. Histopathological and histochemical studies proved the neuroprotective effect of ginseng. Our data showed that ginseng capable to counteract the memory dysfunction is induced by cisplatin via reducing oxidative stress and neuroinflammation restoring the neurological efficiency.

Rhizoma Gastrodiae Water Extract Modulates the Gut Microbiota and Pathological Changes of P-TauThr231 to Protect Against Cognitive Impairment in Mice

Gastrodiae Rhizoma and its active constituents are known to exhibit neuroprotective effects in Alzheimer’s disease (AD). However, the effect of Rhizoma Gastrodiae water extract (WERG) on AD and the detailed mechanism of action remain unclear. In this study, the mechanism of action of WERG was investigated by the microbiome–gut–brain axis using a D-galactose (D-gal)/AlCl₃-induced AD mouse model. WERG improved the cognitive impairment of D-gal/AlCl₃-induced mice. The expression level of p-Tau^thr231 in the WERG-H treatment group was decreased, and p-Tau^thr231 was found negative in hippocampal DG, CA1, and CA3 regions. Here, the diversity and composition of the gut microbiota were analyzed by 16sRNA sequencing. WERG-H treatment had a positive correlation with Firmicutes, Bacilli, Lactobacillus johnsonii, Lactobacillus murinus, and Lactobacillus reuteri. Interestingly, the Rikenellaceae-RC9 gut group in the gut increased in D-gal/AlCl₃-induced mice, but the increased L. johnsonii, L. murinus, and L. reuteri reversed this process. This may be a potential mechanistic link between gut microbiota dysbiosis and P-Tau^Thr231 levels in AD progression. In conclusion, this study demonstrated that WERG improved the cognitive impairment of the AD mouse model by enriching gut probiotics and reducing P-Tau^Thr231 levels.

Crateva unilocalaris Buch. shoots attenuate D-galactose-induced brain injury and cognitive disorders of mice through PI3K/Akt/Nrf2 pathway

Crateva unilocalaris Buch. shoots are traditionally served as vegetable with many health-promoting benefits. The aim of the current investigation was designed to study the preventive effect of ethanol extract from...

Wheat embryo globulin nutrients ameliorate d-galactose and aluminum chloride-induced cognitive impairment in rats

Wheat embryo globulin nutrient (WEGN), with wheat embryo globulin (WEG) as the main functional component, is a nutritional combination that specifically targets memory impairment. In this study, we explored the protective role of WEGN on Alzheimer's disease (AD)-triggered cognitive impairment, neuronal injury, oxidative stress, and acetylcholine system disorder. Specifically, we established an AD model via administration of d-galactose (d-gal) and Aluminum chloride (AlCl₃) for 70 days, then on the 36th day, administered animals in the donepezil and WEGN (300, 600, and 900 mg/kg) groups with drugs by gavage for 35 days. Learning and memory ability of the treated rats was tested using the Morris water maze (MWM) and novel object recognition (NOR) test, while pathological changes and neuronal death in their hippocampus CA1 were detected via HE staining and Nissl staining. Moreover, we determined antioxidant enzymes by measuring levels of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in serum, cortex, and hippocampus, whereas changes in the acetylcholine system were determined by evaluating choline acetyltransferase (ChAT), and acetylcholinesterase (AChE) activities, as well as choline acetylcholine (Ach) content. Results revealed that rats in the WEGN group exhibited significantly lower escape latency, as well as a significantly higher number of targeted crossings and longer residence times in the target quadrant, relative to those in the model group. Notably, rats in the WEGN group spent more time exploring new objects and exhibited lower damage to their hippocampus neuron, had improved learning and memory activity, as well as reversed histological alterations, relative to those in the model group. Meanwhile, biochemical examinations revealed that rats in the WEGN group had significantly lower MDA levels and AChE activities, but significantly higher GSH, SOD, and ChAT activities, as well as Ach content, relative to those in the model group. Overall, these findings indicate that WEGN exerts protective effects on cognitive impairment, neuronal damage, oxidative stress, and choline function in AD rats treated by d-gal/AlCl₃.

Oral Administration of Resveratrol-Selenium-Peptide Nanocomposites Alleviates Alzheimer's Disease-like Pathogenesis by Inhibiting Aβ Aggregation and Regulating Gut Microbiota

Alzheimer's disease (AD) is a neurodegenerative disease associated with amyloid-β (Aβ) deposition, leading to neurotoxicity (oxidative stress and neuroinflammation) and gut microbiota imbalance. Resveratrol (Res) has neuroprotective properties, but its bioavailability in vivo is very low. Herein, we developed a small Res-selenium-peptide nanocomposite to enable the application of Res for eliminating Aβ aggregate-induced neurotoxicity and mitigating gut microbiota disorder in aluminum chloride (AlCl3) and d-galactose(d-gal)-induced AD model mice. Res functional selenium nanoparticles (Res@SeNPs) (8 ± 0.34 nm) were prepared first, after which the surface of Res@SeNPs was decorated with a blood-brain barrier transport peptide (TGN peptide) to generate Res-selenium-peptide nanocomposites (TGN-Res@SeNPs) (14 ± 0.12 nm). Oral administration of TGN-Res@SeNPs improves cognitive disorder through (1) interacting with Aβ and decreasing Aβ aggregation, effectively inhibiting Aβ deposition in the hippocampus; (2) decreasing Aβ-induced reactive oxygen species (ROS) and increasing activity of antioxidation enzymes in PC12 cells and in vivo; (3) down-regulating Aβ-induced neuroinflammation via the nuclear factor kappa B/mitogen-activated protein kinase/Akt signal pathway in BV-2 cells and in vivo; and (4) alleviating gut microbiota disorder, particularly with respect to oxidative stress and inflammatory-related bacteria such as Alistipes, Helicobacter, Rikenella, Desulfovibrio, and Faecalibaculum. Thus, we anticipate that Res-selenium-peptide nanocomposites will offer a new potential strategy for the treatment of AD.

Effect of transcranial near-infrared photobiomodulation on cognitive outcomes in D-galactose/AlCl3 induced brain aging in BALB/c mice

Brain photobiomodulation (PBM) therapy (PBMT) modulates various biological and cognitive processes in senescence rodent models. This study was designed to investigate the effects of transcranial near-infrared (NIR) laser treatment on D-galactose (D-gal)/aluminum chloride (AlCl₃) induced inflammation, synaptic dysfunction, and cognitive impairment in mice. The aged mouse model was induced by subcutaneously injecting D-gal (60 mg/kg/day) followed by intragastrically administering AlCl₃ (200 mg/kg/day) for 2 months. NIR PBM (810 nm laser, 32, 16, and 8 J/cm²) was administered transcranially every other day (3 days/week) for 2 months. Social, contextual, and spatial memories were assessed by social interaction test, passive avoidance test, and Lashley III maze, respectively. Then, tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and synaptic markers including growth-associated protein 43 (GAP-43), post-synaptic density-95 (PSD-95), and synaptophysin (SYN) levels were measured in the hippocampus using western blot method. Behavioral results revealed that NIR PBM at fluencies of 16 and 8 J/cm² could reduce D-gal/AlCl3 impaired social and spatial memories. Treatment with NIR attenuated neuroinflammation through down-regulation of TNF-α and IL-6. Additionally, NIR significantly inhibited the down-regulation of GAP-43 and SYN. The results indicate that transcranial PBM at the fluencies 16 and 8 J/cm² effectively prevents cognitive impairment in mice model of aging by inhibiting the production of the inflammatory cytokines and enhancing synaptic markers.

WIN55,212-2 Attenuates Cognitive Impairments in AlCl3 + d-Galactose-Induced Alzheimer's Disease Rats by Enhancing Neurogenesis and Reversing Oxidative Stress

Neurotransmission and cognitive dysfunctions have been linked to old age disorders including Alzheimer’s disease (AD). Aluminium is a known neurotoxic metal, whereas d-galactose (d-gal) has been established as a senescence agent. WIN55,212-2 (WIN), is a potent cannabinoid agonist which partially restores neurogenesis in aged rats. The current study aimed to explore the therapeutic potentials of WIN on Aluminium chloride (AlCl₃) and d-gal-induced rat models with cognitive dysfunction. Healthy male albino Wistar rats weighing between 200–250 g were injected with d-gal 60 mg/kg intra peritoneally (i.p), while AlCl₃ (200 mg/kg) was orally administered once daily for 10 consecutive weeks. Subsequently, from weeks 8–11 rats were co-administered with WIN (0.5, 1 and 2 mg/kg/day) and donepezil 1 mg/kg. The cognitive functions of the rats were assessed with a Morris water maze (MWM). Furthermore, oxidative stress biomarkers; malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) and neurogenesis markers: Nestin and glial fibrillary acidic protein (GFAP) were also evaluated, as well as the histology of the hippocampus. The results revealed that rats exposed to AlCl₃ and d-gal alone showed cognitive impairments and marked neuronal loss (p < 0.05) in their hippocampal conus ammonis 1 (CA1). Additionally, a significant decrease in the expressions of GFAP and Nestin was also observed, including increased levels of MDA and decreased levels of SOD and GSH. However, administration of WIN irrespective of the doses given reversed the cognitive impairments and the associated biochemical derangements. As there were increases in the levels SOD, GSH, Nestin and GFAP (p < 0.05), while a significant decrease in the levels of MDA was observed, besides attenuation of the aberrant cytoarchitecture of the rat’s hippocampi. The biochemical profiles of the WIN-treated rats were normal. Thus, these findings offer possible scientific evidence of WIN being an effective candidate in the treatment of AD-related cognitive deficits.

Grape skin extract modulates neuronal stem cell proliferation and improves spatial learning in senescence-accelerated prone 8 mice

In recent years, the number of patients with neurodegenerative illness such as Alzheimer’s disease (AD) has increased with the aging of the population. In this study, we evaluated the effect of Grape skin extract (GSE) on neurotypic SH-SY5Y cells as an in vitro AD model, murine neurospheres as an ex vivo neurogenesis model and SAMP8 mice as an in vivo AD model. Our in vitro result showed that pre-treatment of SH-SY5Y cells with GSE ameliorated Aβ-induced cytotoxicity. Moreover, GSE treatment significantly decreased the number of neurospheres, but increased their size suggesting reduced stem cell self-renewal but increased proliferation. Our in vivo Morris water maze test indicated that GSE improves learning and memory in SAMP8 mice. To detect proliferation and newborn neurons, we measured BrdU+ cells in the dentate gyrus (DG). GSE treatment increased the number of BrdU+ cells in the DG of SAMP8 mice. Finally, we showed that GSE induced a decrease in inflammatory cytokines and an increase in neurotransmitters in the cerebral cortex of SAMP8 mice. These results suggested that GSE increased neurogenic zone proliferation and memory but decreased oxidative stress associated with pro-inflammatory cytokines in aging, thus protecting neurons.

The neuroprotection of deproteinized calf blood extractives injection against Alzheimer's disease via regulation of Nrf-2 signaling

Alzheimer’s disease (AD) is characterized by cognitive decline due to the accumulation of extracellular β-amyloid (Aβ) plaques and neurofibrillary tangles in the brain, which impair glutamate (Glu) metabolism. Deproteinized Calf Blood Extractive Injection (DCBEI) is a biopharmaceutical that contains 17 types of amino acids and 5 types of nucleotides. In this study, we found that DCBEI pretreatment reduced L-Glu-dependent neuroexcitation toxicity by maintaining normal mitochondrial function in HT22 cells. DCBEI treatment also reduced the expression of pro-apoptosis proteins and increased the expression of anti-apoptosis proteins. Furthermore, DCBEI attenuated AD-like behaviors (detected via the Morris water maze test) in B6C3-Tg (APPswePSEN1dE9)/Nju double transgenic (APP/PS1) mice; this effect was associated with a reduction in the amount of Aβ and neurofibrillary tangle deposition and the concomitant reduction of phospho-Tau in the hippocampus. Metabonomic profiling revealed that DCBEI regulated the level of neurotransmitters in the hippocampus of APP/PS1 mice. Label-free proteomics revealed that DCBEI regulated the expression of Nrf-2 and its downstream targets, as well as the levels of phospho-protein kinase B and mitogen-activated protein kinase. Together, these data show that DCBEI can ameliorate AD symptoms by upregulating Nrf2-mediated antioxidative pathways and thus preventing mitochondrial apoptosis.

Chinese Herbal Medicine Interventions in Neurological Disorder Therapeutics by Regulating Glutamate Signaling

Glutamate is the major excitatory neurotransmitter in the central nervous system, and its signaling is critical for excitatory synaptic transmission. The well-established glutamate system involves glutamate synthesis, presynaptic glutamate release, glutamate actions on the ionotropic glutamate receptors (NMDA, AMPA, and kainate receptors) and metabotropic glutamate receptors, and glutamate uptake by glutamate transporters. When the glutamate system becomes dysfunctional, it contributes to the pathogenesis of neurodegenerative and neuropsychiatric diseases such as Alzheimer's disease, Parkinson's disease, depression, epilepsy, and ischemic stroke. In this review, based on regulating glutamate signaling, we summarize the effects and underlying mechanisms of natural constituents from Chinese herbal medicines on neurological disorders. Natural constituents from Chinese herbal medicine can prevent the glutamate-mediated excitotoxicity via suppressing presynaptic glutamate release, decreasing ionotropic and metabotropic glutamate receptors expression in the excitatory synapse, and promoting astroglial glutamate transporter expression to increase glutamate clearance from the synaptic cleft. However, some natural constituents from Chinese herbal medicine have the ability to restore the collapse of excitatory synapses by promoting presynaptic glutamate release and increasing ionotropic and metabotropic glutamate receptors expression. These regulatory processes involve various signaling pathways, which lead to different mechanistic routes of protection against neurological disorders. Hence, our review addresses the underlying mechanisms of natural constituents from Chinese herbal medicines that regulate glutamate systems and serve as promising agents for the treatment of the above-mentioned neurological disorders.

Bergamot essential oil attenuate aluminum-induced anxiety-like behavior through antioxidation, anti-inflammatory and GABA regulation in rats

A large number of studies showed that aluminum (Al) has potential neurotoxicity to human and animal bodies. Al-treated animals showed anxiety-like behavior, oxidative stress, neuroinflammation and γ-aminobutyric acid (GABA) changes. Bergamot essential oil (BEO) is a kind of well-known plant extract from the fresh fruit of bergamot. Previous studies suggested that BEO improved mood and relieved symptoms of stress-induced anxiety. This study was designed to study the effects of BEO on anxiety-like behavior, oxidative stress, neuroinflammation and GABA system in aluminum trichloride (AlCl₃) treated rats. Results showed that AlCl₃ exposure induced anxiety-like behavior in the elevated plus maze and the open field test. Moreover, AlCl₃ exposure decreased the level of GABA and the activity of glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in the hippocampus (HP) and the frontal cortex (FC). In addition, AlCl₃ exposure increased the levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) and the levels of interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the HP and the FC. To the contrary, co-administration of BEO and AlCl₃ improved the anxiety-like behavior, GABA system, oxidative stress and neuroinflammation. These results indicated that BEO can alleviate the anxiety-like behavior of AlCl₃-exposed rats through the combined action of antioxidant, anti-inflammatory and GABA regulation.

Partially saturated canthaxanthin alleviates aging-associated oxidative stress in D-galactose administered male wistar rats

It has been earlier reported that partially saturated canthaxanthin (PSC) from Aspergillus carbonarius mutant is non-toxic, has anti-lipid peroxidation activity and can induce apoptosis in prostate cancer cell lines. In the present study, the antiaging effect of PSC was explored in D-galactose administered male wistar rats. 8-10 weeks old, male wistar rats were randomly divided into (i) Vehicle Control Group (VCG), (ii) Aged Control Group (ACG), (iii) Aged + α Lipoic Acid Group (ALG) and (iv) Aged + Partially saturated canthaxanthin Group (APG). Rats received D-galactose (300 mg /kg bwt/day; i.p.) alone (ACG) or together with PSC (APG) (20 mg/kg bwt/day; oral) and α Lipoic Acid (ALG) (80 mg/kg bwt/day; oral) for 10 weeks. Rats in VCG were injected with the same volume of physiological saline (i.p.) and fed with olive oil (vehicle). In vitro protein oxidation and DNA oxidation inhibition, in vivo malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities were determined. In addition, brain neurotransmitters, dopamine and serotonin were estimated by NMR. PSC treatment showed inhibition against protein and DNA oxidation. PSC effectively improved D-galactose induced aging rats by inducing a protective effect through up-regulation of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and brain neurotransmitters and downregulated malondialdehyde (MDA) and monoamineoxidase (MAO) levels. Thus, PSC appears to be a functional compound having antioxidant and antiaging properties.

Effect of Herbal Medicinal Compounds on Alzheimer’s Disease Pathology in APP/PS1 Transgenic Mouse Model

The pathogenesis of Alzheimer’s disease (AD) is complex as various mechanisms interact with each other and, therefore, intervention from a single target is often ineffective. Many studies have shown that herbal medicines, such as curcumin, fisetin, icariin, and ginsenosides, have significant intervention effects on AD with different treatment mechanisms. Therefore, we have designed this study to know whether the combination of these herbal medicines can have an intervention effect on AD through multiple targets. Amyloid precursor protein/presenilin 1(APP/PS1) double transgenic AD mice were used to study the protective effects of a combination of curcumin, piperine, icariin, and ginsenosides, as well as a combination of fisetin, piperine, icariin, and ginsenosides, which were separately mixed into the feed. These herbal medicinal compounds (HMCs) lowered the serum lipid levels, reduced the Aβ oligomers, decreased the pS404-tau protein, as well as neurofibrillary tangles, and restored the reduction of synaptic protein levels and neuronal death of AD mice without causing toxicity to liver and kidneys. In this study, we found that HMCs have significant intervention against AD through multiple targets, providing a novel therapeutic idea for the prevention of AD.

Cognitive-enhancing effects of fibrauretine on Aβ1-42-induced Alzheimer's disease by compatibilization with ginsenosides

Fibrauretine is the main active ingredient in rattan stems of Fibraurea recisa Pierre. The aim of this study was to evaluate the cognitive-enhancing effects and underlying molecular mechanisms of fibrauretine compatibilized with ginsenosides on Alzheimer's disease (AD) induced in mice with amyloid β-protein (Aβ_1-42)_. The results showed that the spatial learning and memory abilities of AD mice were significantly enhanced after combined treatment with fibrauretine and ginsenosides using the Morris water maze test. The levels of acetylcholinesterase (AChE) and phosphorylated Tau protein (p-Tau) in brain tissue and the levels of nitric oxide (NO), malondialdehyde (MDA), and N-terminal pro-brain natriuretic peptide (NT-proBNP) in plasma were significantly increased in Aβ_1-42-induced AD mice, and these effects were reversed after combined treatment with fibrauretine and ginsenosides. By contrast, a significant increase in the levels of catalase (CAT), superoxide dismutase (SOD), choline acetyltransferase (ChAT) and glutathione peroxidase (GSH-Px) was observed in the combined treatment group. The results of haematoxylin and eosin (H&E) staining, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) analysis, immunohistochemistry (IHC) and Western blot analysis showed that the apoptosis rate, Bax, nuclear factor kappa-B p65 (NF-κBp65), cleaved caspase-3 and cleaved caspase-9 expression levels were obviously decreased and that the Bcl-2 expression levels were significantly increased in the hippocampi of mice treated with fibrauretine and ginsenosides. The results of this study show that the ameliorative effect of fibrauretine against AD can be significantly enhanced by compatibilization with ginsenosides. The underlying molecular mechanisms of fibrauretine may be related to antioxidation and anti-apoptosis.

Gelsemine, a natural alkaloid extracted from Gelsemium elegans Benth. alleviates neuroinflammation and cognitive impairments in Aβ oligomer-treated mice

INTRODUCTION

Gelsemine is a natural alkaloid extracted from Gelsemium elegans Benth., a traditional Chinese medicinal herb. Gelsemine has been shown to penetrate the brain, and could produce neurological activities, such as anxiolytic and neuralgia-alleviating effects, suggesting that this natural compound might be used for treating nervous system diseases.

RESULTS

In this study, we have found, for the first time, that gelsemine at low concentrations (5-10 μg/kg) significantly alleviated cognitive impairments induced by β-amyloid (Aβ) oligomer, a main neurotoxin of Alzheimer's disease (AD). In addition, gelsemine substantially prevented Aβ oligomer-induced over-activation of microglia and astrocytes, indicating that gelsemine might reduce AD-related gliosis. Consistently, gelsemine inhibited the over-expression of pro-inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), in the brain of mice. Moreover, gelsemine largely increased the expression of pSer9-glycogen synthase kinase-3β (GSK3β), and decreased the hyper-phosphorylation of tau protein as evidenced by Western blotting analysis. Furthermore, gelsemine prevented Aβ oligomer-induced reduction of PSD-95, a representative post-synaptic protein.

CONCLUSION

All these results directly demonstrated the anti-Aβ oligomer neuroprotective properties of gelsemine, opening a novel perspective for the development of gelsemine-based therapeutics against Aβ-associated neurodegeneration disorders, including AD in particular.

Red Ginseng Inhibits Tau Aggregation and Promotes Tau Dissociation In Vitro

Tau, a microtubule-associated protein expressed in mature neurons, interacts with tubulin to promote the assembly and stabilization of microtubules. However, abnormally hyperphosphorylated tau dissociates from microtubules and self-aggregates. Tau aggregates, including paired helical filaments and neurofibrillary tangles, promote neuronal dysfunction and death and are the defining neuropathological feature of tauopathies. Therefore, suppressing tau aggregation or stimulating the dissociation of tau aggregates has been proposed as an effective strategy for treating neurodegenerative diseases associated with tau pathology such as Alzheimer's disease (AD) and frontotemporal dementia. Interestingly, ginsenosides extracted from Panax ginseng reduced the hippocampal and cortical expression of phosphorylated tau in a rat model of AD. However, no studies have been conducted into the effect of red ginseng (RG) and its components on tau pathology. Here, we evaluated the effect of Korean red ginseng extract (KRGE) and its components on the aggregation and disassociation of tau. Using the thioflavin T assay, we monitored the change in fluorescence produced by the aggregation or disassociation of tau K18, an aggregation-prone fragment of tau₄₄₁ containing the microtubule-binding domain. Our analysis revealed that KRGE not only inhibited tau aggregation but also promoted the dissociation of tau aggregates. In addition, the KRGE fractions, such as saponin, nonsaponin, and nonsaponin fraction with rich polysaccharide, also inhibited tau aggregation and promoted the dissociation of tau aggregates. Our observations suggest that RG could be a potential therapeutic agent for the treatment of neurodegenerative diseases associated with tauopathy.

Torularhodin from Sporidiobolus pararoseus Attenuates d-galactose/AlCl3-Induced Cognitive Impairment, Oxidative Stress, and Neuroinflammation via the Nrf2/NF-κB Pathway

Oxidative stress and neuroinflammation are considered as crucial culprits in Alzheimer's disease (AD). Torularhodin, a carotenoid pigment, possesses powerful antioxidant activity. This study aimed to elucidate the protective effects of torularhodin in the AD-like mouse model and investigated the underlying mechanisms. Behavioral and histopathological results suggested that torularhodin relieved cognitive impairments, attenuated Aβ accumulation, and inhibited glial overactivation in d-gal/AlCl₃-induced ICR mice. Simultaneously, torularhodin also markedly increased antioxidant enzyme capacities, lowered the contents of RAGE, and reduced levels of inflammatory cytokines. Western blot results showed that torularhodin ameliorated neuronal oxidative damage via activation of Nrf2 translocation, upregulation of HO-1, and inactivation of NF-κB in vivo and in vitro. Thus, torularhodin effectively ameliorated cognitive impairment, oxidative stress, and neuroinflammation, possibly through the Nrf2/NF-κB signaling pathways, suggesting torularhodin might offer a promising prevention strategy for neurodegenerative diseases.

Effects of Ginseng on Neurological Disorders

Ginseng (Panax ginseng Meyer), a famous traditional medicinal herb, has been widely used for many centuries. Numerous studies have shown that ginseng has a positive effect on the prevention and treatment of neurological disorders. In this review, we summarized the effects of ginseng in treating neurological diseases, particularly the anti-depressant effects of ginseng. Furthermore, its potential mechanism was also outlined. Therefore, this review may provide new insight into the treatment of ginseng on neurological diseases.

Protective effects of chondroitin sulphate nano-selenium on a mouse model of Alzheimer's disease

In this study, the effect of chondroitin sulphate nano-selenium (CS@Se) on Alzheimer's disease (AD) in mice was investigated. CS@Se alleviated anxiety and improved the spatial learning and memory impairment in AD mice. CS@Se significantly reduced cell oedema and pyknosis, protected the mitochondria, and improved abnormal changes in the ultrastructure of hippocampal neuron synapses of AD mice. Moreover, CS@Se significantly increased the levels of superoxide dismutase(SOD), glutathione peroxidase (GSH-Px), Na⁺/K⁺-ATPase assay (Na⁺/K⁺-ATPase) and acetyltransferase (ChAT), and decreased the levels of malondialdehyde (MDA) and acetylcholinesterase (ChAE) in AD mice. Western blot results showed that CS@Se can attenuate excessive phosphorylation of tau (Ser396/Ser404) by regulating the expression of glycogen synthase kinase-3 beta (GSK-3β). In addition, CS@Se can activate the extracellular signal-regulated kinase 1/2 (ERK 1/2) and p38 mitogen-activated protein kinase (p38 MAPK) signalling pathways to inhibit nuclear transcription factor kappa B (NF-κB) nuclear translocation, thereby regulating the expression of pro-inflammatory cytokines. In summary, CS@Se can reduce oxidative stress damage, inhibit excessive tau phosphorylation, reduce inflammation to delay AD development, and increase the learning and memory capacities of AD mice.

Natural Products and Their Bioactive Compounds: Neuroprotective Potentials against Neurodegenerative Diseases

In recent years, natural products, which originate from plants, animals, and fungi, together with their bioactive compounds have been intensively explored and studied for their therapeutic potentials for various diseases such as cardiovascular, diabetes, hypertension, reproductive, cancer, and neurodegenerative diseases. Neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis are characterized by the progressive dysfunction and loss of neuronal structure and function that resulted in the neuronal cell death. Since the multifactorial pathological mechanisms are associated with neurodegeneration, targeting multiple mechanisms of actions and neuroprotection approach, which involves preventing cell death and restoring the function to damaged neurons, could be promising strategies for the prevention and therapeutic of neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for the treatment of neurodegenerative diseases. This review focused on the therapeutic potential of natural products and their bioactive compounds to exert a neuroprotective effect on the pathologies of neurodegenerative diseases.

Enhanced Neuroprotective Effects of Panax ginseng G115® and Ginkgo biloba GK501® Combinations In Vitro Models of Excitotoxicity

Neurological-related disorders are seen as an increasingly important aspect of welfare. While conventional medicine is still the mainstay for the treatment of these diseases, it is becoming apparent that patients are also seeking more natural and preventative interventions. Panax ginseng G115^® and Ginkgo biloba GK501^® extracts alone or in combination were used in two in vitro experimental models of primary cultures exposed to excitotoxicity: rat organotypic hippocampal slices exposed to either 5 µM kainic acid or 10 µM N-Methyl-d-aspartate for 24 hours, and mixed cortical cells exposed to 300 µM NMDA for 10 min. Cell death in the Cornu Ammonis areas CA3 or CA1 subregions of slices was quantified by measuring propidium iodide fluorescence, whereas in cortical cells, it was assessed by measuring the amount of lactate dehydrogenase. In slices, treatment with extracts alone or in combination significantly attenuated CA3 and CA1 damage induced by exposure to kainic acid or NMDA, respectively. A similar neuroprotective effect was observed in cortical cells exposed to NMDA. Analysis of cell signaling pathways found that the two extracts induced an increase of the phosphorylation and they reversed the decrease of phosphorylation of ERK1/2 and Akt induced by kainic acid and NMDA in organotypic hippocampal slices. These results suggest that P. ginseng G115^® and G. biloba GK501^® extracts may mediate their effects by activating phosphorylation of ERK1/2 and Akt signaling pathways, protecting against excitotoxicity-induced damage in in vitro models.

Centella asiatica Protects d-Galactose/AlCl3 Mediated Alzheimer's Disease-Like Rats via PP2A/GSK-3β Signaling Pathway in Their Hippocampus

Alzheimer's disease (AD) is a progressive neurodegenerative disorder more prevalent among the elderly population. AD is characterised clinically by a progressive decline in cognitive functions and pathologically by the presence of neurofibrillary tangles (NFTs), deposition of beta-amyloid (Aβ) plaque and synaptic dysfunction in the brain. Centella asiatica (CA) is a valuable herb being used widely in African, Ayurvedic, and Chinese traditional medicine to reverse cognitive impairment and to enhance cognitive functions. This study aimed to evaluate the effectiveness of CA in preventing d-galactose/aluminium chloride (d-gal/AlCl3) induced AD-like pathologies and the underlying mechanisms of action were further investigated for the first time. Results showed that co-administration of CA to d-gal/AlCl3 induced AD-like rat models significantly increased the levels of protein phosphatase 2 (PP2A) and decreased the levels of glycogen synthase kinase-3 beta (GSK-3β). It was further observed that, CA increased the expression of mRNA of Bcl-2, while there was minimal effect on the expression of caspase 3 mRNA. The results also showed that, CA prevented morphological aberrations in the connus ammonis 3 (CA 3) sub-region of the rat's hippocampus. The results clearly demonstrated for the first time that CA could alleviate d-gal/AlCl3 induced AD-like pathologies in rats via inhibition of hyperphosphorylated tau (P-tau) bio-synthetic proteins, anti-apoptosis and maintenance of cytoarchitecture.

Protective Effects of Centella asiatica on Cognitive Deficits Induced by D-gal/AlCl₃ via Inhibition of Oxidative Stress and Attenuation of Acetylcholinesterase Level

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with cholinergic dysfunctions and impaired redox homeostasis. The plant Centella asiatica (CA) is renowned for its nutritional benefits and herbal formulas for promoting health, enhancing cognition, and its neuroprotective effects. The present study aims to investigate the protective role of CA on D-gal/AlCl₃-induced cognitive deficits in rats. The rats were divided into six groups and administered with donepezil 1 mg/kg/day, CA (200, 400, and 800 mg/kg/day) and D-gal 60 mg/kg/day + AlCl₃ 200 mg/kg/day for 10 weeks. The ethology of the rats was evaluated by the Morris water maze test. The levels of acetylcholinesterase (AChE), phosphorylated tau (P-tau), malondialdehyde (MDA) and activities of superoxide dismutase (SOD), in the hippocampus and cerebral cortex were estimated by enzyme-linked immunosorbent assay (ELISA). Additionally, the ultrastructure of the prefrontal cortex of the rats’ was observed using transmission electron microscopy (TEM). Rats administered with D-gal/AlCl₃ exhibited cognitive deficits, decreased activities of SOD, and marked increase in AChE and MDA levels. Further, prominent alterations in the ultrastructure of the prefrontal cortex were observed. Conversely, co-administration of CA with D-gal/AlCl₃ improved cognitive impairment, decreased AChE levels, attenuated the oxidative stress in hippocampus and cerebral cortex, and prevented ultrastructural alteration of neurons in the prefrontal cortex. Irrespective of the dose of CA administered, the protective effects were comparable to donepezil. In conclusion, this study suggests that CA attenuated the cognitive deficits in rats by restoring cholinergic function, attenuating oxidative stress, and preventing the morphological aberrations.

Combination of chick embryo and nutrient mixture prevent D-galactose-induced cognitive deficits, immune impairment and oxidative stress in aging rat model

Aging is spontaneous and inevitable processes that lead to changes in biological systems. The present paper was designed to investigate the anti-aging roles of chick embryo (CE) and nutrient mixture (NM) in aging rats. Aging was induced by administration of D-galactose (D-gal, 500 mg/kg/day for 90 days). CE and NM were administered to aging rats through different dose gavage once a day. Cognitive function assessment was performed using the Morris water maze test. At the end of experiment, serum and tissues were collected for immunity and antioxidation function. The organs and tissues were excised for histological study. The results demonstrated that CE plus NM was superior treatment to improve the histopathologic changes and reverse learning and memory impairment of the aging rats. CE plus NM also increased the spleen and thymus index as well as splenocyte proliferation, and reversed inflammatory cytokine levels. In addition, the biochemical index showed that CE plus NM could improve the antioxidant enzyme activity of the aging rats, decrease lipofuscin (LF) and glutamate content. CE plus NM also inhibited the activation of TLR4/NF-κB pathway stimulated by LPS in splenic B lymphocytes. Overall, these results seem to be implying that CE plus NM was used as potentially natural supplement or functional food for preventing aging.

Panax ginseng components and the pathogenesis of Alzheimer's disease (Review)

Ginseng is one of the main representatives of traditional Chinese medicine and presents a wide range of pharmacological actions. Ginsenosides are the main class of active compounds found in ginseng. They demonstrate unique biological activity and medicinal value, namely anti-tumour, anti-inflammatory and antioxidant properties, as well as anti-apoptotic properties. Increasing levels of stress in life are responsible for the increased incidence of nervous system diseases. Neurological diseases create a huge burden on the lives and health of individuals. In recent years, studies have indicated that ginsenosides play a pronounced positive role in the prevention and treatment of neurological diseases. Nevertheless, research is still at an early stage of development, and the complex mechanisms of action involved remain largely unknown. This review aimed to shed light into what is currently known about the mechanisms of action of ginsenosides in relation to Alzheimer's disease. Scientific material and theoretical bases for the treatment of nervous system diseases with purified Panax ginseng extracts are also discussed.

Panax ginseng for Frailty-Related Disorders: A Review

This review aims to understand the clinical efficacy of Panax ginseng (PG) for managing frailty-related disorders by reviewing meta-analyses, systematic reviews, and randomized clinical trial data. PG is widely used in traditional medicine, mainly in East Asia. It has traditionally been indicated for the collapse of qi or for abandoned conditions that manifest as shallow breathing, shortness of breath, cold limbs, profuse sweating, a low pulse rate, or weakness. In accordance with these indications, PG is used for managing conditions such as aging, inflammation, and cancer. PG is also used in some functional foods or supplements. Some studies have shown the effects of ginsenosides, which are the major constituents of PG. With regard to pharmacological activities of ginseng saponins, it has been presumed that these ginsenosides are metabolized into active forms by human intestinal microbiota after being taken orally. Therefore, we focused on reviewing the data of clinical studies on PG. Although there has been no study that directly investigated the effect of PG on frailty, a number of clinical studies have been conducted to investigate the efficacy and safety of PG and its interactions with other modern ginseng medications and ginseng-containing formulas. We searched the randomized controlled trial data from 1995 to 2018 and reviewed the potential effects of PG on frailty-related disorders. We reviewed the effects of PG on glucose metabolism, fatigue, hypertension, cardiovascular disorders, chronic obstructive pulmonary disease, renal function, cognitive function, and immune function. Our review showed some evidence for the usefulness of ginseng, which suggests that it has the potential to be used for the management of aging-related and frailty symptoms, such as fatigue and hypertension. The main limitation of this review is that no study has directly investigated the effect of PG on frailty. Instead we investigated frailty-related disorders, and the limitations of the available studies were small sample sizes and a poor methodological quality; besides, only a few studies targeted elderly people, and few included placebo controls. Larger, well-designed studies are needed to determine the effect of PG on frailty in the future.

Traditional Chinese medicine-based neurorestorative therapy for Alzheimer’s and Parkinson’s disease

The prevalence of multiple neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), has been dramatically increasing, particularly in the aging population. However, the currently available therapies merely alleviate the symptoms of these diseases and are unable to retard disease progression significantly. Traditional Chinese medicine (TCM) has been used in clinical practice for thousands of years for ameliorating symptoms or interfering with the pathogenesis of aging- associated diseases. Modern pharmacological studies have proved that TCM imparts disease-modifying therapeutic effects against these diseases, such as protection of neurons, clearance of protein aggregates, and regulation of neuroinflammation. This review summarizes the evidence from recent studies on AD and PD therapies regarding the neuroprotective activities and molecular mechanisms of a series of TCM formulations comprising herbs and their active ingredients. The findings of this review support the use of TCM as an alternative source of therapy for the treatment of neurodegenerative diseases.

Pharmacodynamic and urinary metabolomics studies on the mechanism of Schisandra polysaccharide in the treatment of Alzheimer's disease

This study was designed to investigate the antagonism of SCP in Aβ25–35-induced AD rats by intervening in neurotransmitters and metabolites.

Protective effect of Centella asiatica against D-galactose and aluminium chloride induced rats: Behavioral and ultrastructural approaches

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder and the commonest cause of dementia among the aged people. _D-galactose (D-gal) is a senescence agent, while aluminium is a known neurotoxin linked to pathogenesis of AD. The combined administration of rats with d-gal and aluminium chloride (AlCl₃) is considered to be an easy and a cheap method to obtain an animal model of AD. The plant Centella asiatica (CA) is reported to exert neuroprotective effects both in vitro and in vivo. Therefore, this study explored the protective effects of CA on cognition and brain ultrastructure in d-gal and AlCl₃ induced rats.

MATERIALS AND METHODS

Rats were exposed to d-gal 60 mg/kg/b.wt/day + AlCl₃ 200 mg/kg/b.wt/day and CA (200, 400 and 800 mg/kg/b.wt/day) and 1 mg/kg/b.wt/day of donepezil for 70 days. Different cognitive paradigms viz. T maze spontaneous alternation, modified elevated plus maze and novel object recognition test, were used to evaluate full lesions of the hippocampus, spatial learning and memory and non-spatial learning and memory respectively. Nissl's staining was used to determine the survival of hippocampus CA1 pyramidal cells, while transmission electron microscopy was used to check the ultrastructural changes.

RESULTS

The results revealed that d-gal and AlCl₃ could significantly impair behavior and cognitive functions, besides causing damage to the hippocampal CA1 pyramidal neurons in rats. In addition, it also caused ultrastructural morphological alterations in rat hippocampus. Conversely, co-administration o;f CA, irrespective of the dosage used, alleviated the cognitive impairments and pathological changes in the rats comparable to donepezil.

CONCLUSION

In conclusion the results suggest that CA could protect cognitive impairments and morphological alterations caused by d-gal and AlCl₃ toxicity in rats. Biochemical and molecular studies are ongoing to elucidate the probable pharmacodynamics of CA.

Targeted Neurotransmitters Profiling Identifies Metabolic Signatures in Rat Brain by LC-MS/MS: Application in Insomnia, Depression and Alzheimer's Disease

Epidemiological, cross-sectional, and prospective studies have suggested that insomnia, Alzheimer’s disease (AD) and depression are mutually interacting conditions and frequently co-occur. The monoamine and amino acid neurotransmitter systems in central nervous system were involved in the examination of neurobiological processes of this symptom complex. However, few studies have reported systematic and contrastive discussion of different neurotransmitters (NTs) changing in these neurological diseases. Thus, it is necessary to establish a reliable analytical method to monitoring NTs and their metabolite levels in rat brain tissues for elucidating the differences in pathophysiology of these neurological diseases. A rapid, sensitive and reliable LC-MS/MS method was established for simultaneous determination of the NTs and their metabolites, including tryptophan (Trp), tyrosine (Tyr), serotonin (5-HT), 5-hydroxyindolacetic acid (5-HIAA), dopamine (DA), acetylcholine (ACh), norepinephrine (NE), glutamic acid (Glu), and γ-aminobutyric acid (GABA) in rat brain tissues. The mobile phase consisting of methanol and 0.01% formic acid in water was performed on an Inertsil EP C18 column, and the developed method was validated well. Results demonstrated that there were significant differences for 5-HT, DA, NE, Trp, Tyr and ACh between model and control group in all three models, and a Bayes linear discriminant function was established to distinguish these three kinds of nervous system diseases by DA, Tyr and ACh for their significant differences among control and three model groups. It could be an excellent strategy to provide perceptions into the similarity and differentia of mechanisms from the point of NTs’ changing in brain directly and a new method to distinguish insomnia, depression and AD from view of essence.

The Effects of Ginsenoside Compound K Against Epilepsy by Enhancing the γ-Aminobutyric Acid Signaling Pathway

The imbalance between the GABA-mediated inhibition and the glutamate-mediated excitation is the primary pathological mechanism of epilepsy. GABAergic and glutamatergic neurotransmission have become the most important targets for controlling epilepsy. Ginsenoside compound K (GCK) is a main metabolic production of the ginsenoside Rb1, Rb2, and Rc in the intestinal microbiota. Previous studies show that GCK promoted the release of GABA from the hippocampal neurons and enhanced the activity of GABA_A receptors. GCK is shown to reduce the expression of NMDAR and to attenuate the function of the NMDA receptors in the brain. The anti-seizure effects of GCK have not been reported so far. Therefore, this study aimed to investigate the effects of GCK on epilepsy and its potential mechanism. The rat model of seizure or status epilepticus (SE) was established with either Pentylenetetrazole or Lithium chloride-pilocarpine. The Racine's scale was used to evaluate seizure activity. The levels of the amino acid neurotransmitters were detected in the pilocarpine-induced epileptic rats. The expression levels of GABA_ARα1, NMDAR1, KCC2, and NKCC1 protein in the hippocampus were determined via western blot or immunohistochemistry after SE. We found that GCK had deceased seizure intensity and prolonged the latency of seizures. GCK increased the contents of GABA, while the contents of glutamate remained unchanged. GCK enhanced the expression of GABA_ARα1 in the brain and exhibited a tendency to decrease the expression of NMDAR1 protein in the hippocampus. The expression of KCC2 protein was elevated by the treatment of GCK after SE, while the expression of NKCC1 protein was reversely down-regulated. These findings suggested that GCK exerted anti-epileptic effects by promoting the hippocampal GABA release and enhancing the GABA_AR-mediated inhibitory synaptic transmission.

Walnut Protein Hydrolysates Play a Protective Role on Neurotoxicity Induced by d-Galactose and Aluminum Chloride in Mice

In recent years, with an increase in the aging population, neurodegenerative diseases have attracted more and more attention. This study aimed to investigate the potential neuroprotective effect of defatted walnut meal protein hydrolysates (DWMPH) on neurotoxicity induced by d-galactose (d-gal) and aluminum chloride (AlCl₃) in mice. The animal models were established by combining treatments with d-gal (200 mg/kg/day, subcutaneously) and AlCl₃ (100 mg/kg in drinking water) for 90 days. During the 90 days, 1 g/kg of DWMPH was administrated orally every day. The results indicated that DWMPH treatment alleviated oxidative stress, reversed cholinergic dysfunction, and suppressed the release of proinflammatory cytokines in the brains of d-gal + AlCl₃-treated mice, and thus improving the learning and memory functions of these mice, which was closely correlated with the strong antioxidant activity of DWMPH. This finding suggests that DWMPH might be a promising dietary supplement in improving neuronal dysfunctions of the brain.