Gypenoside Attenuates β Amyloid-Induced Inflammation in N9 Microglial Cells via SOCS1 Signaling

Therapeutic approaches to microglial dysfunction in Alzheimer's disease: Enhancing phagocytosis and metabolic regulation

Microglia are essential in neurogenesis, synaptic pruning, and homeostasis. Nevertheless, aging, and cellular senescence may modify their role, causing them to shift from being shields to being players of neurodegeneration. In the aging brain, the population of microglia increases, followed by enhanced activity of genes related to neuroinflammation. This change increases their ability to cause inflammation, resulting in a long-lasting state of inflammation in the brain that harms the condition of neurons. In Alzheimer's Disease (AD), microglia are located inside amyloid plaques and exhibit an inflammatory phenotype characterized by a diminished ability to engulf and remove waste material, worsening the illness's advancement. Genetic polymorphisms in TREM2, APOE, and CD33 highlight the significant impact of microglial dysfunction in AD. This review examines therapeutic approaches that aim to address microglial dysfunction, such as enhancing the microglial capability to engulf and remove amyloid-β clumps and regulating microglial metabolism and mitochondrial activity. Microglial transplanting and reprogramming advancements show the potential to restore their ability to reduce inflammation. Although there has been notable advancement, there are still voids in our knowledge of microglial biology, including their relationships with other brain cells. Further studies should prioritize the improvement of human AD models, establish standardized methods for characterizing microglia, and explore how various factors influence microglial responses. It is essential to tackle these problems to create effective treatment plans that focus on reducing inflammation in the brain and protecting against damage in age-related neurodegenerative illnesses.

Neuroprotective effects of Gypenosides: A review on preclinical studies in neuropsychiatric disorders

Gynostemma pentaphyllum (Thunb.) Makino is a perennial creeping herb belonging to the Cucurbitaceae family that has a long history of usage in traditional oriental medicine. Gypenosides are the primary bioactive compounds in Gynostemma pentaphyllum. Because of the medicinal value of gypenosides, functional food and supplements containing gypenosides have been promoted and consumed with popularity, especially among Asian communities. This review presented the progress made in the research of pharmacological properties of gypenosides on diseases of the nervous system and their possible mechanism of action. To date, preclinical studies have demonstrated the therapeutic effects of gypenosides in alleviating neuropsychiatric disorders like depression, Parkinson's disease, Alzheimer's disease, secondary dementia, stroke, optic neuritis, etc. Pharmacological studies have discovered that gypenosides can modulate various major signaling pathways like NF-κB, Nrf2, AKT, ERK1/2, contributing to the neuroprotective properties. However, there is a dearth of clinical research on gypenosides, with current investigations on the compounds being mainly conducted in vitro and on animals. Future studies focusing on isolating and purifying novel gypenosides and investigations on exploring the potential molecular mechanism underlying their biological activities are warranted, which may serve as a foundation for further clinical trials for the betterment of human health.

Herbal medicines in Alzheimer's disease and the involvement of gut microbiota

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by memory loss and cognitive impairment. It severely affects the quality of life of victims. The prevalence of AD has been increasing in recent years. Therefore, it is of great importance to elucidate the pathogenic mechanism of AD and search for effective therapeutic approaches. Gut microbiota dysbiosis, an altered state of gut microbiota, has been well known for its involvement in the pathogenesis of AD. Much effort has been made in searching for approaches capable of modulating the composition of gut microbiota in recent years. Herbal medicines have attracted extensive attention in recent decades for the prevention and treatment of AD. Here, we gave an overview of the recent research progress on the modulatory effects of herbal medicines and herbal formulae on gut microbiota as well as the possible beneficial effects on AD, which may provide new insights into the discovery of anti-AD agents and their therapeutic potential for AD through modulating the composition of gut microbiota.

Targeting Microglia in Alzheimer's Disease: Pathogenesis and Potential Therapeutic Strategies

Microglia, as resident macrophages in the central nervous system, play a multifunctional role in the pathogenesis of Alzheimer's disease (AD). Their clustering around amyloid-β (Aβ) deposits is a core pathological feature of AD. Recent advances in single-cell RNA sequencing (scRNA-seq) and single-nucleus RNA sequencing (snRNA-seq) have revealed dynamic changes in microglial phenotypes over time and across different brain regions during aging and AD progression. As AD advances, microglia primarily exhibit impaired phagocytosis of Aβ and tau, along with the release of pro-inflammatory cytokines that damage synapses and neurons. Targeting microglia has emerged as a potential therapeutic approach for AD. Treatment strategies involving microglia can be broadly categorized into two aspects: (1) enhancing microglial function: This involves augmenting their phagocytic ability against Aβ and cellular debris and (2) mitigating neuroinflammation: Strategies include inhibiting TNF-α signaling to reduce the neuroinflammatory response triggered by microglia. Clinical trials exploring microglia-related approaches for AD treatment have garnered attention. Additionally, natural products show promise in enhancing beneficial effects and suppressing inflammatory responses. Clarifying microglial dynamics, understanding their roles, and exploring novel therapeutic approaches will advance our fight against AD.

Advances in drug delivery-based therapeutic strategies for renal fibrosis treatment

Renal fibrosis is the result of all chronic kidney diseases and is becoming a major global health hazard. Currently, traditional treatments for renal fibrosis are difficult to meet clinical needs due to shortcomings such as poor efficacy or highly toxic side effects. Therefore, therapeutic strategies that target the kidneys are needed to overcome these shortcomings. Drug delivery can be attained by improving drug stability and addressing controlled release and targeted delivery of drugs in the delivery category. By combining drug delivery technology with nanosystems, controlled drug release and biodistribution can be achieved, enhancing therapeutic efficacy and reducing toxic cross-wise effects. This review discusses nanomaterial drug delivery strategies reported in recent years. Firstly, the present review describes the mechanisms of renal fibrosis and anti-renal fibrosis drug delivery. Secondly, different nanomaterial drug delivery strategies for the treatment of renal injury and fibrosis are highlighted. Finally, the limitations of these strategies are also discussed. Investigating various anti-renal fibrosis drug delivery strategies reveals the characteristics and therapeutic effects of various novel nanosystem-derived drug delivery approaches. This will serve as a reference for future research on drug delivery strategies for renal fibrosis treatment.

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.

Gypenoside XLIX alleviates intestinal injury by inhibiting sepsis-induced inflammation, oxidative stress, apoptosis, and autophagy

Intestinal barrier dysfunction is a significant complication induced by sepsis, yet therapeutic strategies targeting such dysfunction remain inadequate. This study investigates the protective effects of Gypenoside XLIX (Gyp XLIX) against intestinal damage induced by sepsis. Septic intestinal injury in mice was induced by cecum ligation and puncture (CLP) surgery. The biological activity and potential mechanisms of Gyp XLIX were explored through intraperitoneal injection of Gyp XLIX (40 mg/kg). The study demonstrates that Gyp XLIX improves the pathological structural damage of the intestine and increases tight junction protein expression as well as the number of cup cells. Through activation of the nuclear factor erythroid 2-related factor 2 - Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathway, Gyp XLIX enhances antioxidant enzyme levels while reducing the excessive accumulation of reactive oxygen species (ROS). In addition, Gyp XLIX effectively alleviates sepsis-induced intestinal inflammation by inhibiting the nuclear factor kappa B (NF-κB) pathway and activation of the NLRP3 inflammasome. Moreover, Gyp XLIX inhibits cell death through modifying phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, further enhancing its ability to shield the intestinal barrier. The combined action of these molecular mechanisms promotes the restoration of immune balance and reduces excessive autophagy activity induced under septic conditions. In summary, Gyp XLIX exhibits a significant preventive action against intestinal damage brought on by sepsis, with its mechanisms involving the improvement of intestinal barrier function, antioxidative stress, inhibition of inflammatory response, and cell apoptosis. This research offers a potential strategy for addressing intestinal barrier impairment brought on by sepsis.

Role of Network Pharmacology in Prediction of Mechanism of Neuroprotective Compounds

Network pharmacology is an emerging pioneering approach in the drug discovery process, which is used to predict the therapeutic mechanism of compounds using various bioinformatic tools and databases. Emerging studies have indicated the use of network pharmacological approaches in various research fields, particularly in the identification of possible mechanisms of herbal compounds/ayurvedic formulations in the management of various diseases. These techniques could also play an important role in the prediction of the possible mechanisms of neuroprotective compounds. The first part of the chapter includes an introduction on neuroprotective compounds based on literature. Further, network pharmacological approaches are briefly discussed. The use of network pharmacology in the prediction of the neuroprotective mechanism of compounds is discussed in detail with suitable examples. Finally, the chapter concludes with the current challenges and future prospectives.

Gypenoside IX restores Akt/GSK-3β pathway and alleviates Alzheimer's disease-like neuropathology and cognitive deficits

The main pathological changes of Alzheimer's disease (AD), a progressive neurodegenerative disorder, include senile plaque (deposited by amyloid beta), neurofibrillary tangle (formed by paired helical filaments composed of hyperphosphorylated tau), and massive loss of neurons. Currently there is a lack of ideal drugs to halt AD progression. Gypenosides (GPs), a kind of natural product, possesses potential therapeutic effects for neurodegenerative diseases, including AD. However, the specific role and mechanism of GPs for AD remain unclear. In the current study, we used staurosporine (STP), an inducer of apoptosis and causing tau hyperphosphorylation, to mimic AD models, and explored the role and mechanism of Gypenoside IX (one of the extracts of Gynostemma, GP for short name in our experiments) in STP treated primary hippocampal neurons and rats. We found STP not only increased apoptosis and tau hyperphosphorylation, but also significantly increased Aβ production, resulting in synaptic dysfunction and cognitive decline in mimic AD models by STP. GP was found to rescue apoptosis and cognitive impairments caused by STP treatment. Moreover, GP recovered the decreased synaptic proteins PSD95, Synaptophysin and GluR2, and blocked dendritic spine loss. Interestingly, GP decreased the STP induced tau hyperphosphorylation at different sites including S-199, S-202, T-205, T-231, S-262, S-396, and S-404, and at the same time decreased Aβ production through down-regulation of BACE1 and PS1. These effects in STP treated primary hippocampal neurons and rats were accompanied with a restoration of AKT/GSK-3β signaling axis with GP treatment, supporting that dysregulation of AKT/GSK-3β pathway might be involved in STP related AD pathogenesis. The results from our research proved that GP might be a potential candidate compound to reduce neuronal damage and prevent the cognitive decline in 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.

Opportunities and challenges for ribosome-inactivating proteins in traditional Chinese medicine plants

Ribosome-inactivating proteins (RIPs) are a class of cytotoxic rRNA N-glycosylase, which widely exist in higher plants in different taxonomy, including many traditional Chinese medicinal materials and vegetables and fruits. In this paper, the traditional Chinese medicinal plants containing RIPs protein were sorted out, and their pharmacological effects and clinical applications were analyzed. Since many RIPs in traditional Chinese medicine plants exhibit antiviral and antitumor activities and show great clinical application potential, people's interest in these proteins is on the rise. This paper summarizes the possible mechanism of RIPs's anti-virus and anti-tumor effects, and discusses its potential problems and risks, laying a foundation for subsequent research on how to exert its anti-virus and anti-tumor effects.

Effects of Probiotics on Colitis-Induced Exacerbation of Alzheimer's Disease in AppNL-G-F Mice

Alzheimer's disease (AD) is characterized by progressive cognitive decline and is a leading cause of death in the United States. Neuroinflammation has been implicated in the progression of AD, and several recent studies suggest that peripheral immune dysfunction may influence the disease. Continuing evidence indicates that intestinal dysbiosis is an attribute of AD, and inflammatory bowel disease (IBD) has been shown to aggravate cognitive impairment. Previously, we separately demonstrated that an IBD-like condition exacerbates AD-related changes in the brains of the AppNL-G-F mouse model of AD, while probiotic intervention has an attenuating effect. In this study, we investigated the combination of a dietary probiotic and an IBD-like condition for effects on the brains of mice. Male C57BL/6 wild type (WT) and AppNL-G-F mice were randomly divided into four groups: vehicle control, oral probiotic, dextran sulfate sodium (DSS), and DSS given with probiotics. As anticipated, probiotic treatment attenuated the DSS-induced colitis disease activity index in WT and AppNL-G-F mice. Although probiotic feeding significantly attenuated the DSS-mediated increase in WT colonic lipocalin levels, it was less protective in the AppNL-G-F DSS-treated group. In parallel with the intestinal changes, combined probiotic and DSS treatment increased microglial, neutrophil elastase, and 5hmC immunoreactivity while decreasing c-Fos staining compared to DSS treatment alone in the brains of WT mice. Although less abundant, probiotic combined with DSS treatment demonstrated a few similar changes in AppNL-G-F brains with increased microglial and decreased c-Fos immunoreactivity in addition to a slight increase in Aβ plaque staining. Both probiotic and DSS treatment also altered the levels of several cytokines in WT and AppNL-G-F brains, with a unique increase in the levels of TNFα and IL-2 being observed in only AppNL-G-F mice following combined DSS and probiotic treatment. Our data indicate that, while dietary probiotic intervention provides protection against the colitis-like condition, it also influences numerous glial, cytokine, and neuronal changes in the brain that may regulate brain function and the progression of AD.

Key brain cell interactions and contributions to the pathogenesis of Alzheimer's disease

Alzheimer's disease (AD) is the most common neurodegenerative disease worldwide, with the two major hallmarks being the deposition of extracellular β-amyloid (Aβ) plaques and of intracellular neurofibrillary tangles (NFTs). Additionally, early pathological events such as cerebrovascular alterations, a compromised blood-brain barrier (BBB) integrity, neuroinflammation and synaptic dysfunction, culminate in neuron loss and cognitive deficits. AD symptoms reflect a loss of neuronal circuit integrity in the brain; however, neurons do not operate in isolation. An exclusively neurocentric approach is insufficient to understand this disease, and the contribution of other brain cells including astrocytes, microglia, and vascular cells must be integrated in the context. The delicate balance of interactions between these cells, required for healthy brain function, is disrupted during disease. To design successful therapies, it is critical to understand the complex brain cellular connections in AD and the temporal sequence of their disturbance. In this review, we discuss the interactions between different brain cells, from physiological conditions to their pathological reactions in AD, and how this basic knowledge can be crucial for developing new therapeutic strategies.

Gypensapogenin I Ameliorates Isoproterenol (ISO)-Induced Myocardial Damage through Regulating the TLR4/NF-κB/NLRP3 Pathway

Myocardial fibrosis (MF) is a common pathological feature of many heart diseases and seriously threatens the normal activity of the heart. Jiaogulan (Gynostemma pentaphyllum) tea is a functional food that is commercially available worldwide. Gypensapogenin I (Gyp I), which is a novel dammarane-type saponin, was obtained from the hydrolysates of total gypenosides. It has been reported to exert a beneficial anti-inflammatory effect. In our study, we attempted to investigate the efficiency and possible molecular mechanism of Gyp I in cardiac injury treatment induced by ISO. In vitro, Gyp I was found to increase the survival rate of H9c2 cells and inhibit apoptosis. Combined with molecular docking and Western blot analysis, Gyp I was confirmed to regulate the TLR4/NF-κB/NLRP3 signaling pathway. In vivo, C57BL6 mice were subcutaneously injected with 10 mg/kg ISO to induce heart failure. Mice were given a gavage of Gyp I (10, 20, or 40 mg/kg/d for three weeks). Pathological alterations, fibrosis-, inflammation-, and apoptosis-related molecules were examined. By means of cardiac function detection, biochemical index analysis, QRT-PCR monitoring, histopathological staining, immunohistochemistry, and Western blot analysis, it was elucidated that Gyp I could improve cardiac dysfunction, alleviate collagen deposition, and reduce myocardial fibrosis (MF). In summary, we reported for the first time that Gyp I showed good myocardial protective activity in vitro and in vivo, and its mechanism was related to the TLR4/NF-κB/NLRP3 signaling pathway.

Modulation of Inflammatory Mediators and Microglial Activation Through Physical Exercise in Alzheimer's and Parkinson's Diseases

Neuroinflammation is an inflammatory process in the central nervous system (CNS), in addition to being one of the main features of Alzheimer's disease (AD) and Parkinson's disease (PD). Microglia are known for their immune functions and have multiple reactive phenotypes related to the types of stages involving neurodegenerative diseases. Depending on the state of activation of microglia in the CNS, it can be neuroprotective or neurotoxic. In this context, AD is a neurodegenerative and neuroinflammatory disease characterized by the deposition of beta-amyloid plaques, formation of fibrillar tangles of tau protein, and loss of neurons due to neurotoxic activation of microglia. However, PD is characterized by the loss of dopaminergic neurons in the substantia nigra and accumulation of alpha-synuclein in the cortical regions, spinal cord, and brain stem, which occurs by microglial activation, contributing to the neuroinflammatory process. In this aspect, the activation of microglia in both pathologies triggers high levels of inflammatory markers, such as interleukins, and causes the neuroinflammatory process of the diseases. Thus, physical exercise is pointed out as neuroprotective, as it can act to strengthen neurogenesis and reduce the inflammatory process. Therefore, the present review addresses the neuroprotective effect of microglia after different types of physical exercise protocols and evaluates the activity and effects of inflammatory and anti-inflammatory parameters and mechanisms of AD and PD. This review will discuss the anti-inflammatory effects of physical exercise through microglia activation with neuroprotective activity and the role of pro-and anti-inflammatory cytokines in AD and PD.

Near-Infrared Fluorescent Probes as Imaging and Theranostic Modalities for Amyloid-Beta and Tau Aggregates in Alzheimer's Disease

A person suspected of having Alzheimer's disease (AD) is clinically diagnosed for the presence of principal biomarkers, especially misfolded amyloid-beta (Aβ) and tau proteins in the brain regions. Existing radiotracer diagnostic tools, such as PET imaging, are expensive and have limited availability for primary patient screening and pre-clinical animal studies. To change the status quo, small-molecular near-infrared (NIR) probes have been rapidly developed, which may serve as an inexpensive, handy imaging tool to comprehend the dynamics of pathogenic progression in AD and assess therapeutic efficacy in vivo. This Perspective summarizes the biochemistry of Aβ and tau proteins and then focuses on structurally diverse NIR probes with coverages of their spectroscopic properties, binding affinity toward Aβ and tau species, and theranostic effectiveness. With the summarized information and perspective discussions, we hope that this paper may serve as a guiding tool for designing novel in vivo imaging fluoroprobes with theranostic capabilities in the future.

Glial cells in Alzheimer's disease: From neuropathological changes to therapeutic implications

Alzheimer's disease (AD) is a neurodegenerative disorder that usually develops slowly and progressively worsens over time. Although there has been increasing research interest in AD, its pathogenesis is still not well understood. Although most studies primarily focus on neurons, recent research findings suggest that glial cells (especially microglia and astrocytes) are associated with AD pathogenesis and might provide various possible therapeutic targets. Growing evidence suggests that microglia can provide protection against AD pathogenesis, as microglia with weakened functions and impaired responses to Aβ proteins are linked with elevated AD risk. Interestingly, numerous findings also suggest that microglial activation can be detrimental to neurons. Indeed, microglia can induce synapse loss via the engulfment of synapses, possibly through a complement-dependent process. Furthermore, they can worsen tau pathology and release inflammatory factors that cause neuronal damage directly or through the activation of neurotoxic astrocytes. Astrocytes play a significant role in various cerebral activities. Their impairment can mediate neurodegeneration and ultimately the retraction of synapses, resulting in AD-related cognitive deficits. Deposition of Aβ can result in astrocyte reactivity, which can further lead to neurotoxic effects and elevated secretion of inflammatory mediators and cytokines. Moreover, glial-induced inflammation in AD can exert both beneficial and harmful effects. Understanding the activities of astrocytes and microglia in the regulation of AD pathogenesis would facilitate the development of novel therapies. In this article, we address the implications of microglia and astrocytes in AD pathogenesis. We also discuss the mechanisms of therapeutic agents that exhibit anti-inflammatory effects against AD.

Gypensapogenin I Suppresses Cell Proliferation in Triple-Negative Breast Cancer Via Triggering the Closure of AKT/GSK3β/β-Catenin and Notch-1 Signaling Pathways

Jiaogulan (Gynostemma pentaphyllum) tea is a functional food that is commercially available worldwide. Gypensapogenin I (Gyp I), which is a natural damarane-type saponin, was obtained from the hydrolysates of total gypenosides. The present research was performed to investigate the potential antiproliferation effect of Gyp I in MDA-MB-231 cells and the underlying mechanisms. Here, we found that Gyp I attenuated survival, inhibited proliferation, and induced apoptosis in MDA-MB-231 cells. Target prediction by binding molecule docking and western blot assays confirmed the mechanism by which Gyp I inhibited the proliferation of breast cancer cells via the AKT/GSK3β/β-catenin signaling pathway. We also showed that Gyp I exhibited superior in vivo efficacy that was dose dependent. Tumor tissue transcriptome analysis indicated that Gyp I could decrease the expression levels of NOTCH1 and HES1, which was in contrast to the effect on MAML and NUMBL, indicating that our compound hindered the activation of the Notch-1 signaling pathway. In summary, we report for the first time that Gyp I shows excellent anti-breast cancer activity in vivo and in vitro and that its pathway of action is related to the AKT/GSK3β/β-catenin and Notch-1 signaling pathways. Therefore, Jiaogulan tea can not only be used as a health food but also possesses the possibility to treat triple-negative breast cancer (TNBC).

Gypenoside-Induced Apoptosis via the PI3K/AKT/mTOR Signaling Pathway in Bladder Cancer

Gynostemma pentaphyllum (Thunb.) Makino (G. pentaphyllum) is a natural herbal drug that has been widely used to treat many diseases. The antitumor effects of G. pentaphyllum were first described in the illustrated catalog of plants. Gypenosides are the major active components of G. pentaphyllum, and they have been widely reported to possess antitumor effects in prostate cancer, gastric cancer, hepatocellular carcinoma, colon cancer, lung cancer, and breast cancer. However, research on the use of gypenoside in the treatment of bladder cancer has not been conducted. In this study, we explored the potential molecular mechanisms of gypenosides in the treatment of bladder cancer using network pharmacology and experimental validation. First, we used a network pharmacology-based method to identify both the effective components of gypenosides and the molecular mechanism underlying their antibladder cancer effects. The results were further confirmed by molecular docking, CCK8 and colony formation assays, and cell cycle and cell apoptosis analyses. Additionally, a mouse xenograft model of bladder cancer was used to investigate the antitumor effect of gypenosides in vivo. We identified 10 bioactive ingredients and 163 gene targets of gypenosides. Network exploration suggested that VEGFA, STAT3, and PI3KCA may be candidate agents for the antibladder cancer effect of gypenosides. In addition, analysis of the Kyoto Encyclopedia of Genes and Genomes pathway revealed that the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway may play a crucial role in the mechanism of action of gypenosides against bladder cancer. Molecular docking revealed that gypenosides combine well with PI3K, AKT, and mTOR. As expected, gypenosides displayed apoptosis-inducing properties in bladder cancer cells by inactivating the PI3K/AKT/mTOR signaling pathway in vitro. Furthermore, gypenosides significantly (P < 0.05) inhibited the growth of bladder cancer cells in vivo. Mechanistically, gypenosides induced the apoptosis of bladder cancer cells via inactivation of the PI3K/AKT/mTOR signaling pathway.

Network pharmacology analysis reveals neuroprotection of Gynostemma pentaphyllum (Thunb.) Makino in Alzheimer' disease

Background

Alzheimer’s disease (AD) is one of the most common neurodegenerative disorders in the world, but still lack of effective drug treatment. Gynostemma Pentaphyllum (Thunb.) Makino (GpM), a Chinese medicinal herb, plays important roles in anti-inflammation, anti-oxidative stress and anti-tumor, which has been reported to ameliorate cognitive impairment of AD. However, the neuroprotective mechanism of GpM remains unclear. This study aims to investigate the targets and possible signaling pathways of GpM in the treatment of AD.

Methods

Active compounds of GpM and their putative target proteins were selected from Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database and Analysis Platform. AD-associated targets were identified from GeneCards, the Online Mendelian Inheritance in Man (OMIM) database and the Therapeutic Target Database (TTD). The intersecting targets of GpM and AD were identified and Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were carried out to analyze the mechanism of them. Compound-target-pathway (CTP) network and protein–protein interaction (PPI) network were constructed and analyzed to elucidate the correlation between compounds, proteins and pathways. Molecular docking was performed to further demonstrate the possibility of GpM for AD.

Results

A total of 13 active compounds of GpM, 168 putative target proteins of compounds and 722 AD-associated targets were identified. Eighteen intersecting targets of GpM and AD were found and the epidermal growth factor receptor (EGFR), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), nitric oxide synthase in endothelial (NOS3) and serum paraoxonase/arylesterase 1 (PON1) were selected as the primary targets of GpM in the treatment of AD. The neuroprotective effect of GPM was related to a variety of pathways, including amoebiasis, HIF-1 signaling pathway, cytokine-cytokine receptor interaction and so on.

Conclusions

Our findings elucidate the active compounds, targets and pathways of GpM involved in effects of anti-AD. The novel mechanism of GpM against AD provides more treatment options for AD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03534-z.

Prebiotic properties of jiaogulan in the context of gut microbiome

Jiaogulan (Gynostemma pentaphyllum) is a traditional Chinese medicinal herb that has been widely used in food and supplemental products. In the last 20 years, extensive research has been conducted to investigate the medicinal prospects of jiaogulan, and in this regard, more than 200 compounds have been isolated with various medicinal properties such as anticancer, anti-obesity, anti-inflammation, and antioxidation. In respect of potential benefits, jiaogulan market is likely growing, and various food items comprised of jiaogulan (beverage, sport drinks, cola, beer, tea, bread, and noodles) have been commercialized in the United States of America, China, and other Asian countries. More recently, there has been growing interest in the prebiotic potential of jiaogulan, especially at the interface of the gut microbiota. This review focuses on the prebiotic and therapeutic aspects of saponins and polysaccharides of jiaogulan tea by summarizing the literature on cancer, obesity, antioxidant activity, and immune-modulatory properties.

Differences in Immune-Related Genes Underlie Temporal and Regional Pathological Progression in 3xTg-AD Mice

The prevalence of Alzheimer’s disease (AD), the most common cause of age-associated dementia, is estimated to increase over the next decades. Evidence suggests neuro-immune signaling deregulation and risk genes beyond the amyloid-β (Aβ) deposition in AD pathology. We examined the temporal profile of inflammatory mediators and microglia deactivation/activation in the brain cortex and hippocampus of 3xTg-AD mice at 3- and 9-month-old. We found upregulated APP processing, decreased expression of CD11b, CX3CR1, MFG-E8, TNF-α, IL-1β, MHC-II and C/EBP-α and increased miR-146a in both brain regions in 3-month-old 3xTG-AD mice, suggestive of a restrictive regulation. Enhanced TNF-α, IL-1β, IL-6, iNOS, SOCS1 and Arginase 1 were only present in the hippocampus of 9-month-old animals, though elevation of HMGB1 and reduction of miR-146a and miR-124 were common features in the hippocampus and cortex regions. miR-155 increased early in the cortex and later in both regions, supporting its potential as a biomarker. Candidate downregulated target genes by cortical miR-155 included Foxo3, Runx2 and CEBPβ at 3 months and Foxo3, Runx2 and Socs1 at 9 months, which are implicated in cell survival, but also in Aβ pathology and microglia/astrocyte dysfunction. Data provide new insights across AD state trajectory, with divergent microglia phenotypes and inflammatory-associated features, and identify critical targets for drug discovery and combinatorial therapies.

Gynostemma pentaphyllum extract and its active component gypenoside L improve the exercise performance of treadmill-trained mice

BACKGROUND/OBJECTIVES

The effectiveness of natural compounds in improving athletic ability has attracted attention in both sports and research. Gynostemma pentaphyllum (Thunb.) leaves are used to make traditional herbal medicines in Asia. The active components of G. pentaphyllum, dammarane saponins, or gypenosides, possess a range of biological activities. On the other hand, the anti-fatigue effects from G. pentaphyllum extract (GPE) and its effective compound, gypenoside L (GL), remain to be determined.

MATERIALS/METHODS

This study examined the effects of GPE on fatigue and exercise performance in ICR mice. GPE was administered orally to mice for 6 weeks, with or without treadmill training. The biochemical analysis in serum, glycogen content, mRNA, and protein expressions of the liver and muscle were analyzed.

RESULTS

The ExGPE (exercise with 300 mg/kg body weight/day of GPE) mice decreased the fat mass percentage significantly compared to the ExC mice, while the ExGPE showed the greatest lean mass percentage compared to the ExC group. The administration of GPE improved the exercise endurance and capacity in treadmill-trained mice, increased glucose and triglycerides, and decreased the serum creatine kinase and lactate levels after intensive exercise. The muscle glycogen levels were higher in the ExGPE group than the ExC group. GPE increased the level of mitochondrial biogenesis by enhancing the phosphorylation of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) protein and the mRNA expression of nuclear respiratory factor 1, mitochondrial DNA, peroxisome proliferator-activated receptor-δ, superoxide dismutase 2, and by decreasing the lactate dehydrogenase B level in the soleus muscle (SOL). GPE also improved PGC-1α activation in the SOL significantly through AMPK/p38 phosphorylation.

CONCLUSIONS

These results showed that GPE supplementation enhances exercise performance and has anti-fatigue activity. In addition, the underlying molecular mechanism was elucidated. Therefore, GPE is a promising candidate for developing functional foods and enhancing the exercise capacity and anti-fatigue activity.

Gynostemma pentaphyllum extract and Gypenoside L enhance skeletal muscle differentiation and mitochondrial metabolism by activating the PGC-1α pathway in C2C12 myotubes

BACKGROUND/OBJECTIVES

Peroxisome proliferator-activated receptor-gamma co-activator-1α (PGC-1α) has a central role in regulating muscle differentiation and mitochondrial metabolism. PGC-1α stimulates muscle growth and muscle fiber remodeling, concomitantly regulating lactate and lipid metabolism and promoting oxidative metabolism. Gynostemma pentaphyllum (Thumb.) has been widely employed as a traditional herbal medicine and possesses antioxidant, anti-obesity, anti-inflammatory, hypolipemic, hypoglycemic, and anticancer properties. We investigated whether G. pentaphyllum extract (GPE) and its active compound, gypenoside L (GL), affect muscle differentiation and mitochondrial metabolism via activation of the PGC-1α pathway in murine C2C12 myoblast cells.

MATERIALS/METHODS

C2C12 cells were treated with GPE and GL, and quantitative reverse transcription polymerase chain reaction and western blot were used to analyze the mRNA and protein expression levels. Myh1 was determined using immunocytochemistry. Mitochondrial reactive oxygen species generation was measured using the 2′7′-dichlorofluorescein diacetate assay.

RESULTS

GPE and GL promoted the differentiation of myoblasts into myotubes and elevated mRNA and protein expression levels of Myh1 (type IIx). GPE and GL also significantly increased the mRNA expression levels of the PGC-1α gene (Ppargc1a), lactate metabolism-regulatory genes (Esrra and Mct1), adipocyte-browning gene fibronectin type III domain-containing 5 gene (Fndc5), glycogen synthase gene (Gys), and lipid metabolism gene carnitine palmitoyltransferase 1b gene (Cpt1b). Moreover, GPE and GL induced the phosphorylation of AMP-activated protein kinase, p38, sirtuin1, and deacetylated PGC-1α. We also observed that treatment with GPE and GL significantly stimulated the expression of genes associated with the anti-oxidative stress response, such as Ucp2, Ucp3, Nrf2, and Sod2.

CONCLUSIONS

The results indicated that GPE and GL enhance exercise performance by promoting myotube differentiation and mitochondrial metabolism through the upregulation of PGC-1α in C2C12 skeletal muscle.

MicroRNA miR-27b-3p regulate microglial inflammation response and cell apoptosis by inhibiting A20 (TNF-α-induced protein 3)

Inflammatory reaction exerts a pivotal role in secondary damage after cerebral hemorrhage and spinal cord injury. miRNAs can both promote and inhibit inflammatory actions among microglial cells. The objective of the present paper was to figure out whether miR-27b-3p produced regulatory effects during processes of microglial inflammation. Lipopolysaccharides (LPS) were used to prepare microglial activation models. Following miR-27b-3p overexpression and interference, the RNA and protein levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β were subjected to real-time fluorescent quantitative PCR (qPCR) and western blot assays, respectively. Cellular apoptosis was subjected to flow cytometry and miR-27b-3p target genes were visualized using a dual luciferase reporter system for verification. The levels of TNF-α, IL-6, and IL-1β mRNA in miR-27b-3p-overexpressed microglial cells were markedly increased compared to the control. Apoptosis of microglial cells was increased markedly in the overexpressed miR-27b-3p group compared to the negative control. Conversely, a different result was presented in the microglial transfected with miR-27b-3p inhibitors. The downregulation of A20, a miR-27b-3p target gene, mediated levels of TNF-α, IL-6, and IL-1β. Furthermore, A20 reduced microglial apoptosis. These data revealed that miR-27b-3p could mediate not only microglia activation but also neuroinflammation via downregulating A20 expression. Thus, miR-27b-3p is regarded as gene therapy in treating cerebral hemorrhage and spinal cord injury.

SOCS1 Mediates Berberine-Induced Amelioration of Microglial Activated States in N9 Microglia Exposed to β Amyloid

Attenuating β amyloid- (Aβ-) induced microglial activation is considered to be effective in treating Alzheimer's disease (AD). Berberine (BBR) can reduce microglial activation in Aβ-treated microglial cells; the mechanism, however, is still illusive. Silencing of cytokine signaling factor 1 (SOCS1) is the primary regulator of many cytokines involved in immune reactions, whose upregulation can reverse the activation of microglial cells. Microglia could be activated into two different statuses, classic activated state (M1 state) and alternative activated state (M2 state), and M1 state is harmful, but M2 is beneficial. In the present study, N9 microglial cells were exposed to Aβ to imitate microglial activation in AD. And Western blot and immunocytochemistry were taken to observe inducible nitric oxide synthase (iNOS), Arginase-1 (Arg-1), and SOCS1 expressions, and the enzyme-linked immunosorbent assay (ELISA) was used to measure inflammatory and neurotrophic factor release. Compared with the normal cultured control cells, Aβ exposure markedly increased the level of microglial M1 state markers (P < 0.05), including iNOS protein expression, tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 releases, and BBR administration upregulated SOSC1 expression and the level of microglial M2 state markers (P < 0.05), such as Arg-1 expression, brain-derived neurotrophic factor (BDNF), and glial cell-derived neurotrophic factor (GDNF) releases, downregulating the SOCS1 expression by using siRNA, however, significantly reversed the BBR-induced effects on microglial M1 and M2 state markers and SOCS1 expression (P < 0.05). These findings indicated that BBR can inhibit Aβ-induced microglial activation via modulating the microglial M1/M2 activated state, and SOCS1 mediates the process.

Progress in the Medicinal Value, Bioactive Compounds, and Pharmacological Activities of Gynostemma pentaphyllum

Gynostemma pentaphyllum (Thunb.) Makino (GP), also named Jiaogulan in Chinese, was known to people for its function in both health care and disease treatment. Initially and traditionally, GP was a kind of tea consumed by people for its pleasant taste and weight loss efficacy. With the passing of the centuries, GP became well known as more than just a tea. Until now, numbers of bioactive compounds, including saponins (also named gypenosides, GPS), polysaccharides (GPP), flavonoids, and phytosterols were isolated and identified in GP, which implied the great medicinal worth of this unusual tea. Both in vivo and in vitro tests, ranging from different cell lines to animals, indicated that GP possessed various biological activities including anti-cancer, anti-atherogenic, anti-dementia, and anti-Parkinson's diseases, and it also had lipid-regulating effects as well as neuroprotection, hepatoprotective, and hypoglycemic properties. With the further development and utilization of GP, the research on the chemical constituents and pharmacological properties of GP were deepening day by day and had made great progress. In this review, the recent research progress in the bioactive compounds, especially gypenosides, and the pharmacological activities of GP were summarized, which will be quite useful for practical applications of GP in the treatment of human diseases.

Triterpenoids from the genus Gynostemma: Chemistry and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

G. pentaphyllum, also known as Jiao-Gu-Lan, has been used traditionally as folk remedies for many diseases, including diabetes mellitus, metabolic syndrome, aging, and neurodegenerative diseases in China and some countries in East and Southeast Asia. It is considered as an "immortality herb" in Guizhou Province, because it was consumed regularly by the elderly native inhabitants. Other species of the same genus Gynostemma such as G. longipes and G. laxum have been used as alternatives to G. pentaphyllum in ethno-medicine in Vietnam and other Asian countries.

AIM OF THE REVIEW

The review aims to summarize up-to-date study results on Gynostemma species, including traditional usage, phytochemical profile, pharmacological activities, and toxicological studies, in order to suggest future research orientation and therapeutic applications on acute and chronic diseases.

MATERIALS AND METHODS

The relevant literature on the genus Gynostemma was gathered from secondary databases (Web of Science and PubMed), books, and official websites. The latest literature cited in this review was published in February 2020.

RESULTS

The genus Gynostemma has been widely used in traditional medicine, mainly for treatment of diabetes, hypertension, obesity, and hepatosteatosis. To date, 328 dammarane-type saponins were isolated and structurally elucidated from Gynostemma species. Crude extracts, saponin-rich fractions (gypenosides), and pure compounds were reported to show a wide range of pharmacological activities in both in vitro and in vivo experiments. The most notable pharmacological effects were anti-cancer, cardioprotective, hepatoprotective, neuroprotective, anti-diabetic, anti-obesity, and anti-inflammatory activities. Toxicological studies were conducted only on G. pentaphyllum, showing that the plant extracts were relatively safe in both acute and long-term toxicity experiments at the given dosage while no toxicological studies were reported for the other species.

CONCLUSIONS

The review summarizes current studies on traditional uses, phytochemistry, biological properties, and toxicology of medicinal Gynostemma species. Till now, the majority of publications still focused only on G. pentaphyllum. However, the promising preliminary data of other Gynostemma species indicated the research potential of this genus, both in phytochemical and pharmacological aspects. Furthermore, clinical data are required to evaluate the efficacy and undesired effects of crude extracts, standard saponin fractions, and pure compounds prepared from Gynostemma medicinal plants.

Gypenosides Inhibit Inflammatory Response and Apoptosis of Endothelial and Epithelial Cells in LPS-Induced ALI: A Study Based on Bioinformatic Analysis and in vivo/vitro Experiments

Introduction

Severe inflammatory response leads to poor prognosis of acute lung injury (ALI), the role of gypenosides (GPs) on ALI is not fully clear. The study aimed at investigating the effects of GPs on ALI.

Methods

We firstly established LPS-induced ALI mice model. Then, we tested whether GPs contributed to alleviate inflammatory response and lung injury of ALI in vivo. In order to identify specific mechanisms of the phenomenon, we conducted a bioinformatic analysis of LPS-induced ALI mice based on GEO database to identify hub differentially expressed genes (DEGs). PPI network of the DEGs was used to find hub-genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were conducted based on the DAVID database to identify which pathways the genes enriched. Then, we tested whether GPs inhibited lung injury and inflammatory response via the enriched pathways. We also tested whether GPs inhibited the apoptosis of endothelial and epithelial cells secondary to severe inflammation.

Results

We found GPs significantly alleviated lung injury and improved the survival rate of LPS-induced ALI mice in vivo. Bioinformatic analysis identified 20 hub-genes from DEGs, they were mainly enriched in NF-κB and TNF-α pathways. GPs could reduce the lung injury and inflammatory response via inhibiting NF-κB and TNF-α pathways in vivo. Our results indicated that GPs also inhibited inflammatory response of epithelial and endothelial cells via NF-κB and TNF-α pathways in vitro. Severe inflammatory response could also lead to apoptosis of endothelial and epithelial cells. Our results indicated that GPs effectively inhibited the apoptosis of endothelial and epithelial cells.

Conclusion

Our study suggested GPs contributed to alleviated lung injury in vivo and inhibited inflammation and apoptosis of endothelial and epithelial cells in vitro, providing novel strategies for the prevention and therapy for ALI.

Particulate Matter Exposure Exacerbates Amyloid-β Plaque Deposition and Gliosis in APP/PS1 Mice

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ) plaques, neuroinflammation, and neuronal death. There are several well-established genetic and environmental factors hypothesized to contribute to AD progression including air pollution. However, the molecular mechanisms by which air pollution exacerbates AD are unclear.

OBJECTIVE

This study explored the effects of particulate matter exposure on AD-related brain changes using the APP/PS1 transgenic model of disease.

METHODS

Male C57BL/6;C3H wild type and APP/PS1 mice were exposed to either filtered air (FA) or particulate matter sized under 2.5μm (PM2.5) for 6 h/day, 5 days/week for 3 months and brains were collected. Immunohistochemistry for Aβ, GFAP, Iba1, and CD68 and western blot analysis for PS1, BACE, APP, GFAP, and Iba1 were performed. Aβ ELISAs and cytokine arrays were performed on frozen hippocampal and cortical lysates, respectively.

RESULTS

The Aβ plaque load was significantly increased in the hippocampus of PM2.5-exposed APP/PS1 mice compared to their respective FA controls. Additionally, in the PM2.5-exposed APP/PS1 group, increased astrocytosis and microgliosis were observed as indicated by elevated GFAP, Iba1, and CD68 immunoreactivities. PM2.5 exposure also led to an elevation in the levels of PS1 and BACE in APP/PS1 mice. The cytokines TNF-α, IL-6, IL-1β, IFN-γ, and MIP-3α were also elevated in the cortices of PM2.5-exposed APP/PS1 mice compared to FA controls.

CONCLUSION

Our data suggest that chronic particulate matter exposure exacerbates AD by increasing Aβ plaque load, gliosis, and the brain inflammatory status.

Herbal Medicine for Slowing Aging and Aging-associated Conditions: Efficacy, Mechanisms and Safety

Aging and aging-associated diseases are issues with unsatisfactory answers in the medical field. Aging causes important physical changes which, even in the absence of the usual risk factors, render the cardiovascular system prone to some diseases. Although aging cannot be prevented, slowing down the rate of aging is entirely possible to achieve. In some traditional medicine, medicinal herbs such as Ginseng, Radix Astragali, Ganoderma lucidum, Ginkgo biloba, and Gynostemma pentaphyllum are recognized by the "nourishing of life" and their role as anti-aging phytotherapeutics is increasingly gaining attention. By mainly employing PubMed here we identify and critically analysed 30 years of published studies focusing on the above herbs' active components against aging and aging-associated conditions. Although many plant-based compounds appear to exert an anti-aging effect, the most effective resulted in being flavonoids, terpenoids, saponins, and polysaccharides, which include astragaloside, ginkgolide, ginsenoside, and gypenoside specifically covered in this review. Their effects as antiaging factors, improvers of cognitive impairments, and reducers of cardiovascular risks are described, as well as the molecular mechanisms underlying the above-mentioned effects along with their potential safety. Telomere and telomerase, PPAR-α, GLUTs, FOXO1, caspase-3, bcl-2, along with SIRT1/AMPK, PI3K/Akt, NF-κB, and insulin/insulin-like growth factor-1 pathways appear to be their preferential targets. Moreover, their ability to work as antioxidants and to improve the resistance to DNA damage is also discussed. Although our literature review indicates that these traditional herbal medicines are safe, tolerable, and free of toxic effects, additional well-designed, large-scale randomized control trials need to be performed to evaluate short- and long-term effects and efficacy of these medicinal herbs.

Traditional Chinese Medicine: Role in Reducing β-Amyloid, Apoptosis, Autophagy, Neuroinflammation, Oxidative Stress, and Mitochondrial Dysfunction of Alzheimer's Disease

Alzheimer's disease (AD) is a progressive age-related neurodegenerative disease characterized by memory loss and cognitive impairment. The major characteristics of AD are amyloid β plaques, apoptosis, autophagy dysfunction, neuroinflammation, oxidative stress, and mitochondrial dysfunction. These are mostly used as the significant indicators for selecting the effects of potential drugs. It is imperative to explain AD pathogenesis and realize productive treatments. Although the currently used chemical drugs for clinical applications of AD are effective in managing the symptoms, they are inadequate to achieve anticipated preventive or therapeutic outcomes. There are new strategies for treating AD. Traditional Chinese Medicine (TCM) has accumulated thousands of years of experience in treating dementia. Nowadays, numerous modern pharmacological studies have verified the efficacy of many bioactive ingredients isolated from TCM for AD treatment. In this review, representative TCM for the treatment of AD are discussed, and among these herbal medicines, the Lamiaceae family accounts for the highest proportion. It is concluded that monomers and extracts from TCM have potential therapeutic effect for AD treatment.

Medicinal Value and Potential Therapeutic Mechanisms of Gynostemma pentaphyllum (Thunb.) Makino and Its Derivatives: An Overview

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Gynostemma pentaphyllum (Thunb.) Makino (GpM) and its derivatives, especially gypenosides (Gyps), are widely used as safe and convenient natural herbal drugs for the treatment of many diseases for a long time, and Gyps have different oral bioavailability (OB) values and low ability to cross the blood-brain barrier (BBB). The effects of GpM and isolates on fibrosis, inflammation, oxidation, proliferation and migration are proved. GpM shows bidirectional regulation effect on proliferation, oxidation and apoptosis in tumor and non-tumor cells. GpM and its extractions can resist proliferation, activate oxidation and apoptosis in tumor cells and have opposite effects on non-tumor cells. We succinctly present some current views of medicinal value and potential therapeutic mechanisms of GpM and its derivatives.

Gypenosides Prevent H2O2-Induced Retinal Ganglion Cell Apoptosis by Concurrently Suppressing the Neuronal Oxidative Stress and Inflammatory Response

Our previous study demonstrated that gypenosides (Gp) exert protective effects on retinal nerve fibers and axons in a mouse model of experimental autoimmune optic neuritis. However, the therapeutic mechanisms remain unclear. Thus, in this study, a model of oxidative damage in retinal ganglion cells (RGCs) was established to investigate the protective effect of Gp, and its possible influence on oxidative stress in RGCs. Treatment of cells with H₂O₂ induced RGC injury owing to the generation of intracellular reactive oxygen species (ROS). In addition, the activities of antioxidative enzymes decreased and the expression of inflammatory factors increased, resulting in an increase in cellular apoptosis. Gp helped RGCs to become resistant to oxidation damage by directly reducing the amount of ROS in cells and exerting protective effects against H₂O₂-induced apoptosis. Treatment with Gp also reduced the generation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and increased nuclear respiratory factor 2 (Nrf-2) levels so as to increase the levels of heme oxygenase-1 (HO-1) and glutathione peroxidase 1/2 (Gpx1/2), which can enhance antioxidation in RGCs. In conclusion, our data indicate that neuroprotection by Gp involves its antioxidation and anti-inflammation effects. Gp prevents apoptosis through a mitochondrial apoptotic pathway. This finding might provide novel insights into understanding the mechanism of the neuroprotective effects of gypenosides in the treatment of optic neuritis.

CZYH Alleviates β-Amyloid-Induced Cognitive Impairment and Inflammation Response via Modulation of JNK and NF-κB Pathway in Rats

Cu-Zhi-Yi-Hao (CZYH), an empirical formula of traditional Chinese medicine (TCM), has been used for amnesia treatment in clinical practice. However, its underlying pharmacological mechanism has not been fully illuminated. The current study was designed to investigate the neuroprotective effect of CZYH on a β-amyloid 25-35- (Aβ_25-35-) induced learning and memory deficit rat model. CZYH (200, 400, or 800 mg/kg), donepezil (1.0 mg/kg), or distilled water was given to Aβ_25-35-stimulated animals for 17 days consecutively. The Morris water maze test revealed that CZYH (400 or 800 mg/kg) administration improved the Aβ_25-35-induced cognitive impairments in rats, and Nissl staining demonstrated that CZYH mitigated the Aβ-caused neuron loss. In addition, CZYH treatment markedly inhibited the activation of microglia as evidenced by a decreased level of IBA-1 and increased YM-1/2 protein expression. The protein expression levels of TNF-α, IL-1β, and COX-2 were also repressed by CZYH. Besides, CZYH treatment alleviated Aβ-induced IκB-α degradation and NF-κB p65 phosphorylation, as well as reduced the JNK phosphorylation level. In conclusion, the present study suggests that CZYH could improve learning and memory abilities and relieve neuron loss in Aβ_25-35-induced rats, at least partly through inhibition of the neuroinflammatory response via inhibiting the JNK-dependent NF-κB activation, indicating that CZYH might be a promising formula for the treatment of AD.

Curcumin Regulates Anti-Inflammatory Responses by JAK/STAT/SOCS Signaling Pathway in BV-2 Microglial Cells

Microglia play important physiological roles in central nervous system (CNS) homeostasis and in the pathogenesis of inflammatory brain diseases. Inflammation stimulates microglia to secrete cytokines and chemokines that guide immune cells to sites of injury/inflammation. Neuroinflammation is also strongly implicated in the pathogenesis of a number of neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease, for which nutritional intervention could represent a benefit due to a lack of clinically efficacious drugs. To this end, the anti-inflammatory mechanisms of several phytochemicals, including curcumin, have been extensively studied. The present experiments show that the administration of curcumin is able to increase the production of the anti-inflammatory cytokines, IL-4 and IL-10, in murine BV-2 microglial cells treated with lipopolysaccharide (LPS). Consistent with these data, curcumin stimulation upregulates the expression of Suppressors of cytokine signaling (SOCS)-1, whereas phosphorylation of the JAK2 and STAT3 was reduced. Taken together, these results provide evidence that curcumin is able to regulate neuroinflammatory reactions by eliciting anti-inflammatory responses in microglia through JAK/STAT/SOCS signaling pathway modulation.

New Dammarane-type Saponins from Gynostemma pentaphyllum

Six new dammarane-type saponins, gypenosides CP1-6 (16), along with 19 known compounds 7⁻25, were isolated and characterized from the aerial parts of Gynostemma pentaphyllum. Among these compounds, eight dammarane-type saponins, 2, 5, 6, 7, 11, 12, 13, and 15, exhibited the greatest antiproliferative effects against two human tumor cell lines (A549 and HepG2).

Microglia and Astrocytes in Alzheimer's Disease: Implications for Therapy

BACKGROUND

Alzheimer's disease (AD) is a complex neurodegenerative disorder characterized by the progressive loss of neurons, which typically leads to severe impairments in cognitive functions including memory and learning. Key pathological features of this disease include the deposition of highly insoluble amyloid β peptides and the formation of neurofibrillary tangles (NFTs) in the brain. Mounting evidence also implicates sustained glial-mediated inflammation as a major contributor of the neurodegenerative processes and cognitive deficits observed in AD.

METHODS

This paper provides an overview of findings from both human and animal studies investigating the role of microglia and astrocytes in AD, and discusses potential avenues for therapeutic intervention.

RESULTS

Glial-mediated inflammation is a 'double-edged sword', performing both detrimental and beneficial functions in AD. Despite tremendous effort in elucidating the molecular and cellular mechanisms underlying AD pathology, to date, there is no treatment that could prevent or cure this disease. Current treatments are only useful in slowing down the progression of AD and helping patients manage some of their behavioral and cognitive symptoms.

CONCLUSION

A better understanding of the role of microglia and astrocytes in the regulation of AD pathology is needed as this could pave the way for new therapeutic strategies.

Rapamycin suppresses Aβ25-35- or LPS-induced neuronal inflammation via modulation of NF-κB signaling

Rapamycin (RAPA), an inhibitor of mammalian target of rapamycin (mTOR), exhibits a high neuroprotective action against neurodegenerative diseases in mouse models. Since neuroinflammation has been shown to be involved in Alzheimer's disease (AD) development and progression, the aim of this study was to examine the anti-inflammatory role of RAPA in AD in vivo and in vitro, and investigate the underlying mechanisms. We found that amyloid-β (Aβ) induced neuronal inflammation and a remarkable increase in mTOR activity in in-vivo and in-vitro models of inflammation, suggesting the critical role of mTOR signaling in neuronal inflammation. In addition, administration of RAPA was found to down-regulate mTOR, p-mTOR, Nuclear factor kappa B (NF-κB) p65, p-p65, TNF-α, IL-1β and Bax protein expression in Aβ_25-35- or lipopolysaccharides (LPS)-treated mice and cultured Neuro-2a (N2a) cells. Moreover, RAPA disrupted Aβ_25-35-induced nuclear translocation of mTOR and NF-κB. Our findings indicate that RAPA inhibits Aβ_25-35- or LPS-induced neuronal inflammation through suppressing mTOR signaling and reducing nuclear import of NF-κB.

Chitinase1 contributed to a potential protection via microglia polarization and Aβ oligomer reduction in D-galactose and aluminum-induced rat model with cognitive impairments

Chitinase activity is increased in Alzheimer's disease (AD). However, the role of chitinase1 in AD is unknown. We investigated the effects of chitinase1 on Alzheimer's pathology and microglia function. Artificial chitinase1 and chitinase inhibitor (chitinase-IN-2) were used to determine the effects of chitinase1 on inflammatory factors and β-amyloid (Aβ) oligomers deposition in D-galactose/AlCl₃-induced rat model with cognitive impairments. Aβ-treated N9 microglia cells were analyzed to further verify whether the changes in inflammatory factors following chitinase1 treatment were associated with microglia alternative activation. Our data displayed that the activity of chitinase1 was both improved in D-galactose/AlCl₃-injected rats and Aβ-pretreated microglia. Moreover, there was an improvement in cognitive function in chitinase1-treated AD rats. Furthermore, anti-inflammation factors (Arginase 1, Arg-1, mannose receptor type C 1, MRC1/CD206) were increased and pro-inflammation factors (tumor necrosis factor alpha, TNFα, interleukin 1 beta, IL-1β) were decreased in D-galactose/AlCl₃-induced AD rats with chitinase1 treatment. A higher level of M2 markers (Arg-1, MRC1/CD206) and a lower level of classic M1 markers (TNFa, IL-1β) were obtained in Aβ-pretreated N9 cells with chitinase1, suggesting that chitinase1 polarized the microglia into an anti-AD M2 phenotype. We also detected that chitnase1 could weaken the deposition of Aβ oligomers in the brain of D-galactose/ AlCl_3-induced AD rats. In conclusion, Chitinase1 might exert protective effects against AD by polarizing microglia to an M2 phenotype and resisting Aβ oligomer deposition.

Neuroprotective effects of gypenosides in experimental autoimmune optic neuritis

AIM

To determine whether gypenosides have protective effects in experimental autoimmune optic neuritis (EAON).

METHODS

Mice were randomly divided into seven groups: control group, model group, three different density gypenosides monotherapy, methylprednisolone monotherapy, combination of gypenosides and methylprednisolone group. The control group was subcutaneously injected with oil emulsion adjuvant and all other groups were subcutaneously immunized with an emulsified mixture of myelin oligodendrocyte glycoprotein (MOG) 35-55 peptide to induce EAON. Mice in the gypenosides groups were administered injections daily with three concentrations (15 mg/kg, 30 mg/kg, 45 mg/kg) of gypenosides respectively. Mice in the methylprednisolone group and the combination treatment group were injected daily with methylprednisolone (20 mg/kg) or methylprednisolone (20 mg/kg) + gypenosides (30 mg/kg), respectively. After MOG immunization, visual evoked potential (VEP), optical coherence tomography (OCT), and histopathologic examination were performed at 14, 20, 30, and 40d post-inoculation (p.i.). All results were expressed as mean±SEM. The data were evaluated by one-way ANOVA followed by Tukey or Games-Howell test.

RESULTS

Compared with the control group, p2 latency was prolonged in the model group (P=0.041). Combination treatment can alleviated the change in VEP at 20d p.i. (P=0.012). Average peripapillary retinal nerve fiber layer (RNFL) thickness was reduced in the model group (P=0.000, 30d; P=0.000, 40d) and gypenosides treatment remarkably diminished the degree of RNFL degeneration at 30d and 40d p.i (P=0.000, 30d; P=0.000, 40d). The pathomorphological results showed a decrease in demye-lination (P=0.020) and inflammatory reactions in the combination group compared with the model group (20d p.i.). Gypenosides treatment also alleviated the degree of axonal loss (40d p.i.) (P=0.003).

CONCLUSION

Treatment with gypenosides exerts protective effects on retinal nerve fibers and axons in EAON. When combined with gypenosides, methylprednisolone reduces demyelination in the acute stage of EAON.

Resveratrol Attenuates Microglial Activation via SIRT1-SOCS1 Pathway

Microglial activation is involved in a variety of neurological disorders, and overactivated microglial cells can secrete large amount of proinflammatory factors and induce neuron death. Therefore, reducing microglial activation is believed to be useful in treating the disorders. In this study, we used 10 ng/ml lipopolysaccharide plus 10 U/ml interferon γ (LPS/IFNγ) to induce N9 microglial activation and explored resveratrol- (RSV-) induced effects on microglial activation and the underlying mechanism. We found that LPS/IFNγ exposure for 24 h increased inducible nitric oxide synthase (iNOS) and nuclear factor κB (NF-κB) p65 subunit expressions in the cells and enhanced tumor necrosis factor α (TNF-α) and interleukin 1β (IL-1β) releases from the cells. RSV of 25 μM reduced the iNOS and NF-κB p65 subunit expressions and the proinflammatory factors' releases; the knockdown of silent information regulator factor 2-related enzyme 1 (SIRT1) or suppressor of cytokine signaling 1 (SOCS1) by using the small interfering RNA, however, significantly abolished the RSV-induced effects on iNOS and NF-κB p65 subunit expressions and the proinflammatory factors' releases. These findings showed that microglial SIRT1-SOCS1 pathway may mediate the RSV-induced inhibition of microglial activation in the LPS/IFNγ-treated N9 microglia.

Plants Producing Ribosome-Inactivating Proteins in Traditional Medicine

Ribosome-inactivating proteins (RIPs) are enzymes that deadenylate nucleic acids and are broadly distributed in the plant kingdom. Many plants that contain RIPs are listed in the pharmacopoeias of folk medicine all over the world, mostly because of their toxicity. This review analyses the position occupied in traditional medicine by plants from which RIPs have been isolated. The overview starts from the antique age of the Mediterranean area with ancient Egypt, followed by the Greek and Roman classic period. Then, the ancient oriental civilizations of China and India are evaluated. More recently, Unani medicine and European folk medicine are examined. Finally, the African and American folk medicines are taken into consideration. In conclusion, a list of RIP-expressing plants, which have been used in folk medicine, is provided with the geographical distribution and the prescriptions that are recommended by traditional healers. Some final considerations are provided on the present utilization of such herbal treatments, both in developing and developed countries, often in the absence of scientific validation. The most promising prospect for the medicinal use of RIP-expressing plants is the conjugation of purified RIPs to antibodies that recognise tumour antigens for cancer therapy.

Anti-cancer effects of Gynostemma pentaphyllum (Thunb.) Makino (Jiaogulan)

Gynostemma pentaphyllum (Thunb.) Makino (GpM) (Jiaogulan) has been widely used in Chinese medicine for the treatment of several diseases, including hepatitis, diabetes and cardiovascular disease. Furthermore, GpM has recently been shown to exhibit potent anti-cancer activities. In this review, we have summarized recent research progress on the anti-cancer activities and mechanisms of action of GpM, as well as determining the material basis for the anti-cancer effects of GpM by searching the PubMed, Web of Science and China National Knowledge Infrastructure databases. The content of this review is based on studies reported in the literature pertaining to the chemical components or anti-cancer effects of GpM up until the beginning of August, 2016. This search of the literature revealed that more than 230 compounds have been isolated from GpM, and that most of these compounds (189) were saponins, which are also known as gypenosides. All of the remaining compounds were classified as sterols, flavonoids or polysaccharides. Various extracts and fractions of GpM, as well as numerous pure compounds isolated from this herb exhibited inhibitory activity towards the proliferation of cancer cells in vitro and in vivo. Furthermore, the results of several clinical studies have shown that GpM formula could have potential curative effects on cancer. Multiple mechanisms of action have been proposed regarding the anti-cancer activities of GpM, including cell cycle arrest, apoptosis, inhibition of invasion and metastasis, inhibition of glycolysis and immunomodulating activities.