Ginsenoside Rg1 improves cognitive capability and affects the microbiota of large intestine of tree shrew model for Alzheimer's disease

Reevaluating Alzheimer's disease treatment: Can phytochemicals bridge the therapeutic Gap?

Alzheimer's disease (AD) is a growing neurological disorder giving impact cognition and memory, posing a global health challenge with over 55 million individuals affected. It is the 7th foremost cause of dying worldwide, and its pervasiveness is expected to twofold in each five years, reaching 115 million by 2050. AD is characterized by neurofibrillary tangles, senile plaques, and oxidative stress, leading to synaptic failure and cognitive decline. Currently, there is no cure, and available FDA-approved drugs provide only symptomatic relief. The disease progresses through five phases- mild cognitive impairment (MCI), very severe, severe, moderate and mild AD. Research on AD focuses on various neurodegenerative pathways, including inflammation, oxidative stress, genetic factors, environmental variables, and amyloid-beta accumulation. Existing FDA-accepted drugs, like rivastigmine, memantine, galantamine, and donepezil, primarily address early symptoms but have limitations, including side effects and high costs. In this context, phytochemicals from plants, such as resveratrol, huperzine, quercetin, galantamine, and rosmarinic acid, show promise as potential treatments for AD and overcome the challenges and limitation of conventional treatment. These natural substances are being investigated for their ability to lower the risk of AD safely. However, there is a lack of comprehensive knowledge about their application, necessitating further research and clinical trials to explore their potential benefits and limitations. This review serves as an essential reference for advancing future studies on Alzheimer's disease. By thoroughly analyzing neurodegenerative pathways, addressing drug limitations, and highlighting the potential of phytochemicals, we establish a strong foundation for developing innovative therapeutic strategies. Closing the knowledge gap related to the use of phytochemicals in Alzheimer's management is not just important; it is critical for creating novel and more effective treatments for this challenging neurological condition.

Ginsenoside Rg1 improves autophagy dysfunction to ameliorate Alzheimer's disease via targeting FGR proto-oncogene

Alzheimer's disease (AD) is a neurodegeneration driven by beta-amyloid (Aβ) deposits in the brain involving autophagy dysfunction. Ginsenoside Rg1, a pharmacologically active compound found in ginseng, has possible therapeutic effects for AD. This study discovered that FGR proto-oncogene (FGR) was a therapeutic target of Rg1 in AD and it was possibly involved in autophagy. C57BL/6 J mice were injected with 5 μL (1 μg/mL) Aβ1-42 in the right lateral ventricle to establish an AD model. AD mouse hippocampus had high FGR expression. Intragastrically administered Rg1 (40 mg/kg) decreased FGR protein levels in AD mice's hippocampus and improved memory function in AD mice. Both sides of the mice hippocampal fissure were administered with 2 μL lentiviral particles (1 × 107 TU) containing FGR overexpression plasmids. FGR overexpression rendered Rg1 ineffectual in restoring memory function and reducing hippocampal neuron damage. We injected 2 μL lentiviral particles (1 × 107 TU) containing short hairpin RNA plasmids targeting FGR to the mice hippocampal fissures. FGR knockdown improved spatial memory function of AD mice, reduced hippocampal neuron apoptosis, and prevented Aβ accumulation. HT22 cells were transfected with small interfering RNA targeting FGR. FGR knockdown increased the viability of Aβ1-42 treated HT22 cells. BACE1 and LC3II/I protein levels were decreased and p62 and SIRT1 were increased in AD mice and cells with FGR knockdown. LC3 was down-regulated after inhibiting FGR expression in Aβ1-42 treated hippocampal neurons. In conclusion, Rg1 exerts anti-AD functions by targeting FGR and downregulating its expression.

Ginseng and Polygonum multiflorum formula protects brain function in Alzheimer's disease

Background

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with no effective treatment currently available. The Panax ginseng C.A.Mey. and Polygonum multiflorum Thunb. formula (GSPM) has shown potential neuroprotective effects, but its therapeutic efficacy and underlying mechanisms in AD remain unclear and require further investigation.

Methods

In this study, senescence-accelerated mouse prone 8 (SAMP8) mice, an AD model, were treated with GSPM (low: 117 mg/kg, high: 234 mg/kg) or donepezil (1.3 mg/kg) via gavage for 2 months. Cognitive function was assessed using the Morris water maze. Hippocampal morphology was evaluated by H&E staining, and neuronal apoptosis was detected by TUNEL assay. Microgliosis and astrogliosis were analyzed by Iba1 and GFAP immunohistochemistry. Levels of phosphorylated Tau, Aβ1-42, Aβ1-40, inflammatory cytokines, oxidative stress markers, and senescence markers were measured. Gut microbiota composition was analyzed by 16S rRNA sequencing. In vitro, the effects of GSPM were evaluated in Aβ1-42-stimulated HT22 hippocampal neurons. Cell viability was assessed via CCK-8, and apoptosis was detected by flow cytometry. The AMPK/Sirt1 pathway was investigated by Western blotting, and SIRT1-dependent effects were evaluated following EX527 treatment, a SIRT1 inhibitor.

Results

GSPM treatment improved cognitive function, reduced hippocampal tissue damage, and decreased neuronal apoptosis in AD mice. It alleviated neuroinflammation by reducing microgliosis and astrogliosis and lowered the levels of p-Tau protein and Aβ accumulation in both the hippocampus and cerebrospinal fluid. Additionally, GSPM reversed the enhanced inflammation, oxidative stress, and neuronal senescence observed in AD mice. Furthermore, GSPM modulated gut microbiota composition by reducing microbial diversity and restoring the Firmicutes/Bacteroidetes ratio to levels similar to those in control mice. GSPM increased the abundance of Lactobacillus, which was negatively correlated with inflammation, Aβ1-42, p-Tau, and senescence markers. It also decreased the abundance of bacteria, such as Oscillibacter, Helicobacter, and Odoribacter, which are associated with inflammation, oxidative stress, and neuronal senescence. In line with in vivo findings, GSPM increased cell viability, reduced apoptosis, and alleviated oxidative stress in Aβ1-42-stimulated HT22 hippocampal neurons. It also decreased the production of pro-inflammatory cytokines and reduced expression of senescence markers in vitro. Furthermore, GSPM restored AMPK phosphorylation and Sirt1 expression in neurons. Notably, inhibition of Sirt1 by EX527 reversed the neuroprotective effects of GSPM.

Conclusion

Our data demonstrated that GSPM exhibits protective effects on AD via suppressing the inflammation, oxidation, and senescence, possibly through regulating the Sirt1 signaling. These findings provided a novel therapeutic approach for AD.

Gut microbiota: A new key of understanding for Panax notoginseng against multiple disorders and biotransformation

ETHNOPHARMACOLOGICAL RELEVANCE

Panax notoginseng (Burkill) F.H.Chen(P. notoginseng) has been widely used as an herbal medicine for reducing swelling, relieving pain, promoting blood circulation and stopping bleeding, with notable therapeutic effects on obesity, liver diseases, colitis, Alzheimer's disease, chronic kidney disease and other diseases.

AIM OF THE STUDY

This review highlighted the close link and bidirectional effects between P. notoginseng and gut microbiota, with the ultimate aim of providing new insights into the potential mechanisms of pharmacological effects of P. notoginseng in the treatment of different diseases and PNS transformation.

MATERIALS AND METHODS

By means of some reputable databases (PubMed, China National Knowledge Infrastructure (CNKI), Google Scholar, etc.), we screened the published articles related to P. notoginseng from 1998 to 2024, including original research, clinical trials and review on raw materials and chemical constituents of P. notoginseng. Then, we employed the keywords "gut microbiota", "intestinal microbiota", "gut biotransformation" and "intestinal" to exclude the articles that do not in line with our topic. Plant information was obtained from www.worldfloraonline.org using "Panax notoginseng (Burkill) F.H.Chen" as the keyword.

RESULTS

P. notoginseng elevated certain probiotics including Lactobacillus, Bifidobacterium and Akkermansia, while simultaneously reducing pathogenic bacteria such as Prevotellaceae, Enterococcus, Enterobacter and Helicobacter, to fight various diseases. Meanwhile, considering to the low oral bioavailability and degradable properties of Panax notoginseng saponin (PNS), gut microbiota converted it into protopanaxatriol(PPT) and protopanaxadiol(PPD) mainly through deglycosylation reactions to enhance the bioactivity.

CONCLUSION

Increasing evidences suggest that gut microbiota may play a vital role for P. notoginseng exerting on beneficial effects on the prevention and treatment of metabolic disorders, liver diseases, neurological diseases, chronic kidney diseases, vascular diseases, colitis, and other diseases, as well as for biotransformation of P. notoginseng.

Prevention and Treatment of Alzheimer's Disease Via the Regulation of the Gut Microbiota With Traditional Chinese Medicine

Alzheimer's disease (AD) is caused by a variety of factors, and one of the most important factors is gut microbiota dysbiosis. An imbalance in the gut mincrobiota have been shown to change the concentrations of lipopolysaccharide and short-chain fatty acids. These microorganisms synthesize substances that can influence the levels of a variety of metabolites and cause multiple diseases through the immune response, fatty acid metabolism, and amino acid metabolism pathways. Furthermore, these metabolic changes promote the formation of β-amyloid plaques and neurofibrillary tangles. Thus, the microbiota-gut-brain axis plays an important role in AD development. In addition to traditional therapeutic drugs such as donepezil and memantine, traditional Chinese medicines (TCMs) have also showed to significantly decrease the severity of AD symptoms and suppress the underlying related mechanisms. We searched for studies on the effects of different herbal monomers, single herbs, and polyherbal formulas on the gut microbiota of AD patients and identified the relevant pathways through which the gut microbiota affected AD. We conclude that improvements in the gut microbiota not only decrease the occurrence of inflammatory reactions but also reduce the deposition of central pathological products. Herbal monomers have a stronger effect on improving of central pathology. Polyherbal formulas have the most extensive effect on the gut microbiota in patients with AD. Among the effects of formulas, the anti-inflammatory effect is the most essential and is also the main concern regarding the use of TCMs in treating AD from the viewpoint of the gut microbiota. We hope that this review will be helpful for providing new ideas for the clinical application of TCMs in the treatment of AD.

Unveiling the impact of aging on BBB and Alzheimer's disease: Factors and therapeutic implications

Alzheimer's disease (AD) is a highly prevalent neurodegenerative condition that has devastating effects on individuals, often resulting in dementia. AD is primarily defined by the presence of extracellular plaques containing insoluble β-amyloid peptide (Aβ) and neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau protein (P-tau). In addition, individuals afflicted by these age-related illnesses experience a diminished state of health, which places significant financial strain on their loved ones. Several risk factors play a significant role in the development of AD. These factors include genetics, diet, smoking, certain diseases (such as cerebrovascular diseases, obesity, hypertension, and dyslipidemia), age, and alcohol consumption. Age-related factors are key contributors to the development of vascular-based neurodegenerative diseases such as AD. In general, the process of aging can lead to changes in the immune system's responses and can also initiate inflammation in the brain. The chronic inflammation and the inflammatory mediators found in the brain play a crucial role in the dysfunction of the blood-brain barrier (BBB). Furthermore, maintaining BBB integrity is of utmost importance in preventing a wide range of neurological disorders. Therefore, in this review, we discussed the role of age and its related factors in the breakdown of the blood-brain barrier and the development of AD. We also discussed the importance of different compounds, such as those with anti-aging properties, and other compounds that can help maintain the integrity of the blood-brain barrier in the prevention of AD. This review builds a strong correlation between age-related factors, degradation of the BBB, and its impact on AD.

Exploring the Potential Therapeutic Approach Using Ginsenosides for the Management of Neurodegenerative Disorders

There is a need for an efficient and long-lasting treatment due to the population's increasing prevalence of neurodegenerative disorders. In an effort to generate fresh ideas and create novel therapeutic medications, scientists have recently started to investigate the biological functions of compounds derived from plants and herbs. Ginseng, famous Chinese herbal medicine, has therapeutic value by virtue of its compounds ginsenosides or panaxosides, which are triterpene saponins and steroid glycosides. Research revealed positive impacts on ameliorating various disease conditions and found it as a possible drug candidate. Several neuroprotection mechanisms followed by this compound are inhibition of cell apoptosis, oxidative stress, inflammatory, and tumor activity. It has been demonstrated that controlling these mechanisms enhances cognitive performance and safeguards the brain against neurodegenerative disorders. The main objective of this review is to give a description of the most recent studies on ginsenoside's possible therapeutic application in the treatment of neurodegenerative diseases. Using organic compounds like ginseng and its various components may create new avenues for innovative treatment approaches development for neurological diseases. However, further research is necessary to confirm the stability and effectiveness of ginsenosides for neurodegenerative disease.

From ancient wisdom to modern science: Gut microbiota sheds light on property theory of traditional Chinese medicine

The property theory of traditional Chinese medicine (TCM) has been practiced for thousands of years, playing a pivotal role in the clinical application of TCM. While advancements in energy metabolism, chemical composition analysis, machine learning, ion current modeling, and supercritical fluid technology have provided valuable insight into how aspects of TCM property theory may be measured, these studies only capture specific aspects of TCM property theory in isolation, overlooking the holistic perspective inherent in TCM. To systematically investigate the modern interpretation of the TCM property theory from multidimensional perspectives, we consulted the Chinese Pharmacopoeia (2020 edition) to compile a list of Chinese materia medica (CMM). Then, using the Latin names of each CMM and gut microbiota as keywords, we searched the PubMed database for relevant research on gut microbiota and CMM. The regulatory patterns of different herbs on gut microbiota were then summarized from the perspectives of the four natures, the five flavors and the meridian tropism. In terms of the four natures, we found that warm-natured medicines promoted the colonization of specific beneficial bacteria, while cold-natured medicines boosted populations of some beneficial bacteria while suppressing pathogenic bacteria. Analysis of the five flavors revealed that sweet-flavored and bitter-flavored CMMs positively influenced beneficial bacteria while inhibiting harmful bacteria. CMMs with different meridian tropism exhibited complex modulative patterns on gut microbiota, with Jueyin (Liver) and Taiyin (Lung) meridian CMMs generally exerting a stronger effect. The gut microbiota may be a biological indicator for characterizing the TCM property theory, which not only enhances our understanding of classic TCM theory but also contributes to its scientific advancement and application in healthcare. Please cite this article as: Yang YN, Zhan JG, Cao Y, Wu CM. From ancient wisdom to modern science: Gut microbiota sheds light on property theory of traditional Chinese medicine. J Integr Med 2024; 22(4): 413-445.

Classic Famous Prescription Kai-Xin-San Ameliorates Alzheimer's Disease via the Wnt/β-Catenin Signaling Pathway

Kai-Xin-San (KXS) is a classic famous prescription composed of Polygalae Radix, Ginseng Radix et Rhizoma, Acori Tatarinowii Rhizoma, and Poria. Clinically, KXS is effective in treating amnesia and regulating cognitive dysfunction of Alzheimer's disease (AD), whereas its mechanism of action is still unclear. In this study, the AD model rats were established by combining intraperitoneal injection of D-galactose (150 mg/kg/day) and intracerebral injection of Aβ25-35 (10 μL) to investigate the meliorative effect of KXS on AD and explore its mechanism. After 1-month KXS treatment, Morris water maze test showed that different doses of KXS all improved the cognitive impairment of AD rats. The results of hematoxylin and eosin staining, Nissl staining, and Tunnel staining showed that the neuron injury in the hippocampal CA1 region of the AD rats was markedly improved after KXS treatment. Concurrently, KXS reversed the levels of biochemical indexes of AD rats. Furthermore, the protein expressions of Wnt1 and β-catenin in KXS groups were remarkably increased, while the expressions of Bax and caspase-3 were significantly decreased. Besides, KXS-medicated serum reduced the levels of tumor necrosis factor-α, interleukin-1β, and reactive oxygen species and regulated the protein expressions of β-catenin, glycogen synthase kinase-3β (GSK-3β), p-GSK-3β, Bax, and caspase-3 in Aβ25-35-induced pheochromocytoma cells. Most importantly, this effect was attenuated by the Wnt inhibitor IWR-1. Our results suggest that KXS improves cognitive and memory function of AD rats, and its neuroprotective mechanism may be mediated through the Wnt/β-catenin signaling pathway.

Shotgun metagenomics reveals the gut microbial diversity and functions in Vespa mandarinia (Hymenoptera: Vespidae) at multiple life stages

Wasps play important roles as predators and pollinators in the ecosystem. The Jingpo minority residing in Yunnan Province, China, has a traditional practice of using wine infused with mature wasps as a customary remedy for managing rheumatoid arthritis. The larva of the wasp is also a tasteful folk dish that has created a tremendous market. There is a paucity of survival knowledge, which has greatly restricted their potential applications in food and healthcare. Recent research has highlighted the importance of gut microbiota in insect growth. Nevertheless, there is still a lack of understanding regarding the composition, changes, and functions of the gut microbiota in Vespa mandarinia during development. In this research, the gut microbiota were investigated across three growth stages of Vespa mandarinia using a metagenomic technology. The result revealed that there are significant variations in the proportion of main gut microbes during the metamorphosis of Vespa mandarinia. Tenericutes were found to dominate during the larval stage, while Proteobacteria emerged as the dominant group post-pupation. Through a comprehensive analysis of the gut microbiota metagenome, this study revealed functional differences in the wasp gut microbiota at various growth stages. During the larval stage, the gut microbiota plays a central role in promoting metabolism. Following pupation, the gut microbiota exhibited diversified functions, likely due to the complex environments and diverse food sources encountered after metamorphosis. These functions included amino acid metabolism, compound degradation, and defense mechanisms. This research provides an extensive dataset on the gut microbiota during the metamorphosis of Vespa mandarinia, contributing to a deeper understanding of the influence of gut microbiota on wasp growth. Furthermore, this study uncovers a unique microbial treasure within insect guts, which is important for advancing the application of wasps in the fields of food and medicine.

Traditional herbs: mechanisms to combat cellular senescence

Cellular senescence plays a very important role in the ageing of organisms and age-related diseases that increase with age, a process that involves physiological, structural, biochemical and molecular changes in cells. In recent years, it has been found that the active ingredients of herbs and their natural products can prevent and control cellular senescence by affecting telomerase activity, oxidative stress response, autophagy, mitochondrial disorders, DNA damage, inflammatory response, metabolism, intestinal flora, and other factors. In this paper, we review the research information on the prevention and control of cellular senescence in Chinese herbal medicine through computer searches of PubMed, Web of Science, Science Direct and CNKI databases.

Curcumin alleviates Alzheimer's disease by inhibiting inflammatory response, oxidative stress and activating the AMPK pathway

BACKGROUND

Alzheimer's disease (AD) is a common degenerative brain disorder with limited therapeutic options. Curcumin (Cur) exhibits neuroprotective function in many diseases. We aimed to explore the role and mechanism of Cur in AD.

MATERIALS AND METHODS

Firstly, we established AD mice by injecting amyloid-β1-42 (Aβ1-42) solution into the hippocampus. Then, the AD mice received 150 mg/kg/d Cur for 10 consecutive days. The Morris water maze test was conducted to evaluate the cognitive function of the mice by hidden platform training and probe trials. To assess the spatial memory of the mice, spontaneous alternation behavior, the number of crossing the novel arm and the time spent in the novel arm during the Y-maze test was recorded. Hematoxylin and eosin (H&E) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNAL) assay were performed to assess the pathological damage and apoptosis of brain tissues. The number of damaged neurons was inspected by Nissl staining. Immunohistochemical staining was then performed to detect Aβ1-42 deposition. The levels of tumor necrosis factor-α (TNF-a), interleukin-6 (IL-6) and interleukin-1β (IL-1β) in serum and hippocampus, the contents of super oxide dismutase (SOD) and malondialdehyde (MDA) in brain tissues were assessed by enzyme-linked immunosorbent assay (ELISA). Additionally, B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), RelA (p65) protein expressions and Adenosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation were tested using Western blot.

RESULTS

Cur not only improved cognitive function and spatial memory, but also alleviated the pathological damage and apoptosis of brain tissues for AD mice. Meanwhile, upon Cur treatment, the number of damaged neurons in AD mice was decreased, the level of Aβ1-42 in AD mice was significantly decreased. Furthermore, the AD mice treated with Cur exhibited lower TNF-a, IL-6, IL-1β and MDA levels and a higher SOD content. Besides, Cur also downregulated p65 expression and upregulated AMPK phosphorylation.

CONCLUSION

Cur may improve AD via suppressing the inflammatory response, oxidative stress and activating the AMPK pathway, suggesting that Cur may be a potential drug for AD.

Exploring the therapeutic potential of natural compounds for Alzheimer's disease: Mechanisms of action and pharmacological properties

Alzheimer's Disease (AD) is a global public health priority characterized by high mortality rates in adults and an increasing prevalence in aging populations worldwide. Despite significant advancements in comprehending the pathogenesis of AD since its initial report in 1907, there remains a lack of effective curative or preventive measures for the disease. In recent years, natural compounds sourced from diverse origins have garnered considerable attention as potential therapeutic agents for AD, owing to their anti-inflammatory, antioxidant, and neuroprotective properties. This review aims to consolidate the therapeutic effects of natural compounds on AD, specifically targeting the reduction of β-amyloid (Aβ) overproduction, anti-apoptosis, autophagy, neuroinflammation, oxidative stress, endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Notably, the identified compounds exhibiting these effects predominantly originate from plants. This review provides valuable insights into the potential of natural compounds as a reservoir of novel therapeutic agents for AD, thereby stimulating further research and contributing to the development of efficacious treatments for this devastating disease.

Traditional Chinese medicine for the treatment of Alzheimer's disease: A focus on the microbiota-gut-brain axis

Alzheimer's disease (AD), the most frequent cause of dementia, is a neurodegenerative disorder characterised by a progressive decline in cognitive function that is associated with the formation of amyloid beta plaques and neurofibrillary tangles. Gut microbiota comprises of a complex community of microorganisms residing in the gastrointestinal ecosystem. These microorganisms can participate in gut-brain axis activities, thereby affecting cognitive function and associated behaviours. Increasing evidence has indicated that gut dysbiosis can jeopardise host immune responses and promote inflammation, which may be an initiating factor for the onset and evolution of AD. Traditional Chinese medicine (TCM) is a promising resource which encompasses immense chemical diversity and multiple-target characteristics for the treatment of AD. Many TCMs regulate the gut microbiota during treatment of diseases, indicating that gut microbiota may be an important target for TCM efficacy. In this review, we summarised the role of the microbiota-gut-brain axis in the development of AD and the effects of TCM in treating AD by regulating the gut microbiota. We anticipate that this review will provide novel perspectives and strategies for future AD research and treatments.

American Ginseng for the Treatment of Alzheimer's Disease: A Review

Alzheimer's disease (AD) is a prevalent degenerative condition that is increasingly affecting populations globally. American ginseng (AG) has anti-AD bioactivity, and ginsenosides, as the main active components of AG, have shown strong anti-AD effects in both in vitro and in vivo studies. It has been reported that ginsenosides can inhibit amyloid β-protein (Aβ) production and deposition, tau phosphorylation, apoptosis and cytotoxicity, as well as possess anti-oxidant and anti-inflammatory properties, thus suppressing the progression of AD. In this review, we aim to provide a comprehensive overview of the pathogenesis of AD, the potential anti-AD effects of ginsenosides found in AG, and the underlying molecular mechanisms associated with these effects. Additionally, we will discuss the potential use of AG in the treatment of AD, and how ginsenosides in AG may exert more potent anti-AD effects in vivo may be a direction for further research.

Role of microbial dysbiosis in the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is the leading cause of dementia in the elderly and detected during the advanced stages where the chances of reversal are minimum. The gut-brain axis mediates a bidirectional communication between the gut and brain, which is dependent on bacterial products such as short chain fatty acids (SCFA) and neurotransmitters. Accumulating lines of evidence suggests that AD is associated with significant alteration in the composition of gut microbiota. Furthermore, transfer of gut microbiota from healthy individuals to patients can reshape the gut microbiota structure and thus holds the potential to be exploited for the treatment of various neurodegenerative disease. Moreover, AD-associated gut dysbiosis can be partially reversed by using probiotics, prebiotics, natural compounds and dietary modifications, but need further validations. Reversal of AD associated gut dysbiosis alleviate AD-associated pathological feature and therefore can be explored as a therapeutic approach in the future. The current review article will describe various studies suggesting that AD dysbiosis occurs with AD and highlights the causal role by focussing on the interventions that hold the potential to reverse the gut dysbiosis partially.

Ginsenoside Rg1 in neurological diseases: From bench to bedside

Ginseng has been used in China as a superior medicinal material for thousands of years that can nourish the five internal organs, calm the mind and benefit wisdom. Due to its anti-inflammatory, antioxidant and neuroprotective activities, one of the active components of ginseng, ginsenoside Rg1, has been extensively investigated in the remedy of brain disorders, especially dementia and depression. In this review, we summarized the research progress on the action mechanisms of Rg1 ameliorating depression-like behaviors, including inhibition of hyperfunction of hypothalamic-pituitary-adrenal (HPA) axis, regulation of synaptic plasticity and gut flora. Rg1 may alleviate Alzheimer's disease in the early phase, as well as in the middle-late phases through repairing dendrite, axon and microglia- and astrocyte-related inflammations. We also proposed that Rg1 could regulate memory state (the imbalance of working and aversive memory) caused by distinct stimuli. These laboratory studies would further the clinical trials on Rg1. From the prospective of drug development, we discussed the limitations of the present investigations and proposed our ideas to increase permeability and bioavailability of Rg1. Taken together, Rg1 has the potential to treat neuropsychiatric disorders, but a future in-depth investigation of the mechanisms is still required. In addition, drug development will benefit from the clinical trials in one specific neuropsychiatric disorder.

The traditional Chinese medicine and non-small cell lung cancer: from a gut microbiome perspective

Non-small cell lung cancer (NSCLC) is one of the most serious diseases affecting human health today, and current research is focusing on gut flora. There is a correlation between intestinal flora imbalance and lung cancer, but the specific mechanism is not clear. Based on the "lung and large intestine being interior-exteriorly related" and the "lung-intestinal axis" theory. Here, based on the theoretical comparisons of Chinese and western medicine, we summarized the regulation of intestinal flora in NSCLC by active ingredients of traditional Chinese medicine and Chinese herbal compounds and their intervention effects, which is conducive to providing new strategies and ideas for clinical prevention and treatment of NSCLC.

Ginsenoside Rg1 modulates intestinal microbiota and supports re-generation of immune cells in dexamethasone-treated mice

Ginsenoside Rg1 is one of the major ginsenosides found in roots of Panax ginseng and Panax notoginseng. Ginsenoside Rg1 is known to possess various biological activities including immunity enhancement activity. However, it is not clear whether the regulation of immune function by Rg1 is related to the intestinal microbiota. In the present study, the immuno-modulatory and gut microbiota-reshaping effects of ginsenoside Rg1 were evaluated. Ginsenoside Rg1 acts as an immune-enhancing agent to increase spleen index and the number of T, B and dendritic cells in dexamethasone (Dex)-treated mice. Ginsenoside Rg1 also increased the production of sIgA and regulated the expression of interleukin 2 (IL-2), IL-4, IL-10 and IFN-γ. Meanwhile, Rg1 administration regulated the structure of intestinal microbiota. The relative abundance of mouse intestinal microbial groups, such as Alistipes, Ruminococcaceae, Lachnospiraceae, and Roseburia were increased by Rg1 administration, whereas a decrease in the potential pathogens like Helicobacteraceae, Dubosiella, Mycoplasma, Alloprevotella, Allobaculum was observed. Moreover, Rg1 metabolites of Lachnospiraceae bacterium enhanced the proliferation of CD4+ T cells and T regulatory (Treg) cells. Ginsenoside Rg1 improved the inflammatory condition of the colonic tissue and repaired the destructed mucosal barrier. This study suggested that Rg1 strengthens immunity with regulating the homeostasis of intestinal microbiota in mice.

Modulating the Gut Microbiota as a Therapeutic Intervention for Alzheimer's Disease

Growing evidence suggested that the change of composition and proportion of intestinal microbiota may be related to many diseases, such as irritable bowel syndrome, bipolar disorder, Parkinson's disease, as well as Alzheimer's disease. Current literature supports the fact that unbalanced gut microbial composition (gut dysbiosis) is a risk factor for AD. In our review, we briefly sum up the recent progress regarding the correlations between the gut microbiota and AD. Therapeutic interventions capable of modulating the make-up of the gut microflora may exert beneficial effects on AD, preventing or delaying the beginning of AD or counteracting its development. Additionally, well-documented approaches that can positively influence AD may exert their beneficial effects through modifying the gut microbiota. Therefore, other novel interventions which can target on gut microbiota will also be potential therapies for AD. The chances and challenges that AD is confronted with in the research field of microbiomics are also discussed in this review.

Medicinal Herbs and Their Derived Ingredients Protect against Cognitive Decline in In Vivo Models of Alzheimer’s Disease

Alzheimer’s disease (AD) has pathological hallmarks including amyloid beta (Aβ) plaque formation. Currently approved single-target drugs cannot effectively ameliorate AD. Medicinal herbs and their derived ingredients (MHDIs) have multitarget and multichannel properties, engendering exceptional AD treatment outcomes. This review delineates how in in vivo models MHDIs suppress Aβ deposition by downregulating β- and γ-secretase activities; inhibit oxidative stress by enhancing the antioxidant activities and reducing lipid peroxidation; prevent tau hyperphosphorylation by upregulating protein phosphatase 2A expression and downregulating glycogen synthase kinase-3β expression; reduce inflammatory mediators partly by upregulating brain-derived neurotrophic factor/extracellular signal-regulated protein kinase 1/2-mediated signaling and downregulating p38 mitogen-activated protein kinase (p38 MAPK)/c-Jun N-terminal kinase (JNK)-mediated signaling; attenuate synaptic dysfunction by increasing presynaptic protein, postsynaptic protein, and acetylcholine levels and preventing acetylcholinesterase activity; and protect against neuronal apoptosis mainly by upregulating Akt/cyclic AMP response element-binding protein/B-cell lymphoma 2 (Bcl-2)-mediated anti-apoptotic signaling and downregulating p38 MAPK/JNK/Bcl-2-associated x protein (Bax)/caspase-3-, Bax/apoptosis-inducing factor-, C/EBP homologous protein/glucose-regulated protein 78-, and autophagy-mediated apoptotic signaling. Therefore, MHDIs listed in this review protect against Aβ-induced cognitive decline by inhibiting Aβ accumulation, oxidative stress, tau hyperphosphorylation, inflammation, synaptic damage, and neuronal apoptosis in the cortex and hippocampus during the early and late AD phases.

Ginsenoside and Its Therapeutic Potential for Cognitive Impairment

Cognitive impairment (CI) is one of the major clinical features of many neurodegenerative diseases. It can be aging-related or even appear in non-central nerve system (CNS) diseases. CI has a wide spectrum that ranges from the cognitive complaint with normal screening tests to mild CI and, at its end, dementia. Ginsenosides, agents extracted from a key Chinese herbal medicine (ginseng), show great promise as a new therapeutic option for treating CI. This review covered both clinical trials and preclinical studies to summarize the possible mechanisms of how ginsenosides affect CI in different diseases. It shows that ginsenosides can modulate signaling pathways associated with oxidative stress, apoptosis, inflammation, synaptic plasticity, and neurogenesis. The involved signaling pathways mainly include the PI3K/Akt, CREB/BDNF, Keap1/Nrf2 signaling, and NF-κB/NLRP3 inflammasome pathways. We hope to provide a theoretical basis for the treatment of CI for related diseases by ginsenosides.

New Therapeutic Approaches to and Mechanisms of Ginsenoside Rg1 against Neurological Diseases

Neurological diseases, including Parkinson’s disease (PD), Alzheimer’s disease (AD), Huntington’s disease (HD), stroke, cerebral infarction, ischemia-reperfusion injury, depression and, stress, have high incidence and morbidity and often lead to disability. However, there is no particularly effective medication against them. Therefore, finding drugs with a suitable efficacy, low toxicity and manageable effects to improve the quality of life of patients is an urgent problem. Ginsenoside Rg1 (Rg1) is the main active component of ginseng and has a variety of pharmacological effects. In this review, we focused on the therapeutic potential of Rg1 for improving neurological diseases. We introduce the mechanisms of Ginsenoside Rg1 in neurological diseases, including apoptosis, neuroinflammation, the microRNA (miRNA) family, the mitogen-activated protein kinase (MAPK) family, oxidative stress, nuclear factor-κB (NF-κB), and learning and memory of Rg1 in neurological diseases. In addition, Rg1 can also improve neurological diseases through the interaction of different signal pathways. The purpose of this review is to explore more in-depth ideas for the clinical treatment of neurological diseases (including PD, AD, HD, stroke, cerebral infarction, ischemia–reperfusion injury, depression, and stress). Therefore, Rg1 is expected to become a new therapeutic method for the clinical treatment of neurological diseases.

New insights into the role and mechanisms of ginsenoside Rg1 in the management of Alzheimer's disease

Alzheimer's disease (AD) is a common neurodegenerative disorder in the elderly characterized by memory loss and cognitive dysfunction. The pathogenesis of AD is complex. One-targeted anti-AD drugs usually fail to delay AD progression. Traditional Chinese medicine records have documented the use of the roots of Panax ginseng (ginseng roots) and its prescriptions to treat dementia. Ginsenoside Rg1, the main ginsenoside component of ginseng roots, exhibits a certain therapeutic effect in the abovementioned diseases, suggesting its potential in the management of AD. Therefore, we combed the pathogenesis of AD and currently used anti-AD drugs, and reviewed the availability, pharmacokinetics, and pharmaceutic studies of ginsenoside Rg1. This review summarizes the therapeutic effects and mechanisms of ginsenoside Rg1 and its deglycosylated derivatives in AD in vivo and in vitro. The main mechanisms include improvement in Aβ and Tau pathologies, regulation of synaptic function and intestinal microflora, and reduction of inflammation, oxidative stress, and apoptosis. The underlying mechanisms mainly involve the regulation of PKC, MAPK, PI3K/Akt, CDK5, GSK-3β, BDNF/TrkB, PKA/CREB, FGF2/Akt, p21WAF1/CIP1, NF-κB, NLRP1, TLR3, and TLR4 signaling pathways. As the effects and underlying mechanisms of ginsenoside Rg1 on AD have not been systematically reviewed, we have provided a comprehensive review and shed light on the future directions in the utilization of ginsenoside Rg1 and ginseng roots as well as the development of anti-AD drugs.

The microbiota-gut-brain axis and its modulation in the therapy of depression: comparison of efficacy of conventional drugs and traditional Chinese medicine approaches

Depression is a common and severe mental disease that places a heavy burden on human society, which can lead to decreased cognitive function, energy loss, insomnia, and even suicide. Although medication plays an important role in improving the symptoms of depression, approximately one third of people with depression do not significantly benefit from medication and experience various adverse reactions. Recently, increasing evidence has shown that gut microbes play an important role in the occurrence and development of depression. There have been illuminating studies previously conducted on the relationship between antidepressant chemicals, traditional Chinese medicine, and the microbiota-gut-brain axis (MGBA). Therefore, in this review, we summarize the role of the MGBA in the occurrence and development of depression, especially the important role of the MGBA in the mechanism of action of antidepressants. Modulation of the MGBA is proposed to enhance the efficacy of antidepressant drugs and reduce their side effects and disease recurrence, so as to provide a new method for the treatment of depression.

Ginsenoside Rg1 improves Alzheimer's disease by regulating oxidative stress, apoptosis, and neuroinflammation through Wnt/GSK-3β/β-catenin signaling pathway

Alzheimer's disease (AD) is a chronic neurodegenerative disorder that can cause cognitive impairment. Ginsenoside Rg1 (Rg1) has a significant neuroprotective effect on animals with memory impairment. However, the mechanism of how Rg1 mediates the Wnt signaling pathway and improves cognitive function by regulating oxidative stress, apoptosis, and neuroinflammation is still unclear. In this study, the spatial memory ability of tree shrews was tested by Morris water maze, the expression levels of amyloid protein (Aβ1-42), ionized calcium-binding adapter molecule 1 (iba-1), nitrotyrosine (NT), and 8-hydroxyguanine (8-OHG) were detected by immunohistochemistry. Subsequently, the activity of catalase (CAT) and the glutathione peroxidase (GSH-Px) was, respectively, measured by the ammonium molybdate method and the 5,5'-dithiobis (2-nitrobenzoic acid). Furthermore, the malondialdehyde (MDA) concentration was determined by the thiobarbituric acid test. Finally, the expression levels of Beta-secretase (BACE1), superoxide dismutase (SOD), BCL2-Associated X (Bax), B-cell lymphoma-2 (Bcl-2), caspase-anti-apoptotic factor Cleaved-caspase-3 (Caspase-3), microtubule-associated proteins 2 (MAP2), Neuronal nuclear antigen (NeuN), as well as the phosphorylation of GSK-3β and β-catenin were detected by Western blot. This study implied that Rg1 reduced the phosphorylation of Tau protein, the deposition of Aβ1-42, and the expression of BACE1. It also showed that Rg1 increased the antioxidant activity of SOD, CAT, GPx, and instead reduced the oxidation products of NT, 8-OHG, and MDA, as wells as the inflammatory factor interleukin-1 and iba-1. It further showed that Rg1 increased the ratio of Bcl-2 to Bax and expression of neuronal markers MAP2 and NeuN, but instead reduced the expression of Caspase-3, GSK-3β, and β-catenin. In conclusion, by regulating the Wnt/GSK-3β/β-catenin signaling pathway, Rg1 of moderate and high dose could alleviate oxidative stress damage, improve neuroinflammation, protect neurons, finally improve the cognitive impairment of the AD tree shrew. This study provides theoretical basis for the Rg1 clinical application in AD.

Ginsenoside Rg1 Mitigates Porcine Intestinal Tight Junction Disruptions Induced by LPS through the p38 MAPK/NLRP3 Inflammasome Pathway

Inflammation leads to porcine tight junction disruption of small intestinal epithelial cells, resulting in intestinal dysfunction. Herein, we established lipopolysaccharide (LPS)-induced in-vivo and in-vitro inflammatory models. The results revealed that LPS induced tight junction disruption in IPEC-J2 cells by downregulating tight-junction-related protein zonula occludens-1 (ZO-1), occludin and claudin-1 expression, while ginsenoside Rg1 rescued such inhibition and abrogated the upregulated expression of phosphorylation p38 MAPK. The p38 MAPK inhibitor (SB203580) showed a similar effect with Rg1 and attenuated the LPS-induced inhibition of ZO-1, occludin and claudin-1 expression, which is consistent with the reduced expression of NLRP3 inflammasome and IL-1β. Furthermore, the specific inhibitors of NLRP3 and IL-1β result in increased expression of tight-junction-related protein, demonstrating that p38 MAPK signaling was associated with Rg1 suppression of tight junction disruption. Besides, LPS treatment decreased the expression of ZO-1, occludin and claudin-1 through p38 MAPK signaling, and caused abnormal morphological changes in murine ileum. Meanwhile, Rg1 attenuated the decreased expression of ZO-1, occludin and claudin-1 and partially alleviated LPS-induced morphological changes in murine ileum. In summary, these findings characterized a novel mechanism by which Rg1 alleviates LPS-induced intestinal tight junction disruption by inhibiting the p38 MAPK-mediated NLRP3 inflammasome pathway.

Ginsenoside Rg1 Alleviates Acute Ulcerative Colitis by Modulating Gut Microbiota and Microbial Tryptophan Metabolism

Ulcerative colitis (UC) is a chronic and recurrent inflammatory disorder in the gastrointestinal tract. Here, we examined the pharmacological effects of ginsenoside Rg1, a natural compound with low bioavailability, on the acute experimental colitis mice induced by dextran sulfate sodium (DSS) and explored underlying mechanisms. Acute UC was induced in C57BL/6 mice by 2.5% DSS for 7 days, meanwhile, 2 mg/10 g b.w. ginsenoside Rg1 was administrated to treat the mice. Body weight, colon length, colon tissue pathology, and colon tissue inflammatory cytokines were assessed. The composition structure of gut microbiota was profiled using 16s rRNA sequencing. Global metabolomic profiling of the feces was performed, and tryptophan and its metabolites in the serum were detected. The results showed that Rg1 significantly ameliorated DSS-induced colonic injury and colonic inflammation. In addition, Rg1 also partly reversed the imbalance of gut microbiota composition caused by DSS. Rg1 intervention can regulate various metabolic pathways of gut microbiota such as valine, leucine, and isoleucine biosynthesis and vitamin B6 metabolism and the most prominent metabolic alteration was tryptophan metabolism. DSS decreased the levels of tryptophan metabolites in the serum, including indole-3-carboxaldehyde, indole-3-lactic acid, 3-indolepropionic acid, and niacinamide and Rg1 can increase the levels of these metabolites. In conclusion, the study discovered that Rg1 can protect the intestinal barrier and alleviate colon inflammation in UC mice, and the underlying mechanism is closely related to the regulation of gut microbiota composition and microbial tryptophan metabolism.

Qisheng Wan formula ameliorates cognitive impairment of Alzheimer's disease rat via inflammation inhibition and intestinal microbiota regulation

ETHNOPHARMACOLOGY RELEVANCE

Qisheng Wan formula (QWF) was first described in the book Sheng Ji Zong Lu in 1117. The book states that QWF can cure forgetfulness, improve the mind, and make people smart. Hence, QWF has been widely used to treat patients with forgetfulness or dementia. QWF, a classic Chinese formulation, comprises seven herbal drugs: the sclerotium of Poria cocos (Schw.) Wolf, bark of Cinnamomum cassia Presl, root of Polygala tenuifolia Willd., root and rhizome of Panax ginseng C. A. Mey., root of Asparagus cochinchinensis (Lour.) Merr., root and rhizome of Acorus tatarinowii Schott, and root bark of Lycium chinense Mill.

AIM OF THE STUDY

This study aimed to utilize modern pharmacological methods to evaluate the therapeutic effects and explore the underlying mechanism of QWF action on rats with Alzheimer's disease (AD).

MATERIALS AND METHODS

The chemical profile of QWF was characterized using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The AD rat model was established via a bilateral intraventricular injection of amyloid-β (1-42) (Aβ_1-42). The rats were subsequently treated daily with QWF for 4 weeks. The Morris water maze test was performed to evaluate the cognition processes in the rats, whereas histological changes in the hippocampus were observed using hematoxylin and eosin staining. The expression levels of Aβ_1-42, nuclear factor-kappa B (NF-κB), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 in the hippocampus and colon were assessed. Moreover, the diversity and composition of the intestinal microbiota were analyzed using 16S rDNA gene sequencing.

RESULTS

One hundred and fourteen compounds were characterized in QWF. QWF significantly ameliorated the cognition processes and histopathological damages due to AD in rats by decreasing the deposition of Aβ_1-42 and downregulating the expression of NF-κB, TNF-α, and IL-6. QWF also modulated changes in the diversity and composition of intestinal microbiota to suppress the relative abundance of inflammation-associated microbiota.

CONCLUSION

This study showed that QWF can suppress proinflammatory factors and modulate the intestinal microbiota in AD rats.

Gram-negative bacteria and their lipopolysaccharides in Alzheimer's disease: pathologic roles and therapeutic implications

Alzheimer's disease (AD) is the most serious age-related neurodegenerative disease and causes destructive and irreversible cognitive decline. Failures in the development of therapeutics targeting amyloid-β (Aβ) and tau, principal proteins inducing pathology in AD, suggest a paradigm shift towards the development of new therapeutic targets. The gram-negative bacteria and lipopolysaccharides (LPS) are attractive new targets for AD treatment. Surprisingly, an altered distribution of gram-negative bacteria and their LPS has been reported in AD patients. Moreover, gram-negative bacteria and their LPS have been shown to affect a variety of AD-related pathologies, such as Aβ homeostasis, tau pathology, neuroinflammation, and neurodegeneration. Moreover, therapeutic approaches targeting gram-negative bacteria or gram-negative bacterial molecules have significantly alleviated AD-related pathology and cognitive dysfunction. Despite multiple evidence showing that the gram-negative bacteria and their LPS play a crucial role in AD pathogenesis, the pathogenic mechanisms of gram-negative bacteria and their LPS have not been clarified. Here, we summarize the roles and pathomechanisms of gram-negative bacteria and LPS in AD. Furthermore, we discuss the possibility of using gram-negative bacteria and gram-negative bacterial molecules as novel therapeutic targets and new pathological characteristics for AD.