Akebia saponin D reverses corticosterone hypersecretion in an Alzheimer's disease rat model

Akebia saponin D attenuates allergic airway inflammation through AMPK activation

Akebia saponin D (ASD) is a bioactive triterpenoid saponin extracted from Dipsacus asper Wall. ex DC.. This study aimed to investigate the effects of ASD on allergic airway inflammation. Human lung epithelial BEAS-2B cells and bone marrow-derived mast cells (BMMCs) were pretreated with ASD (50, 100 and 200 μΜ) and AMPK activator 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) (1 mM), and then stimulated with lipopolysaccharide (LPS) or IL-33. Pretreatment with ASD and AICAR significantly inhibited TNF-α and IL-6 production from BEAS-2B cells, and IL-13 production from BMMCs. Moreover, pretreatment with ASD and AICAR significantly increased p-AMPK expression in BEAS-2B cells. Inhibition of AMPK by siRNA and compound C partly abrogated the suppression effect of ASD on TNF-α, IL-6, and IL-13 production. Asthma murine model was induced by ovalbumin (OVA) challenge and treated with ASD (150 and 300 mg/kg) or AICAR (100 mg/kg). Infiltration of eosinophils, neutrophils, monocytes, and lymphocytes, and production of TNF-α, IL-6, IL-4, and IL-13 were attenuated in ASD and AICAR treated mice. Lung histopathological changes were also ameliorated after ASD and AICAR treatment. Additionally, it showed that treatment with ASD and AICAR increased p-AMPK expression in the lung tissues. In conclusion, ASD exhibited protective effects on allergic airway inflammation through the induction of AMPK activation.

Integrating network pharmacology and transcriptomic omics reveals that akebia saponin D attenuates neutrophil extracellular traps-induced neuroinflammation via NTSR1/PKAc/PAD4 pathway after intracerebral hemorrhage

Neutrophils and their production of neutrophil extracellular traps (NETs) significantly contribute to neuroinflammation and brain damage after intracerebral hemorrhage (ICH). Although Akebia saponin D (ASD) demonstrates strong anti-inflammatory activities and blood-brain barrier permeability, its role in regulating NETs formation and neuroinflammation following ICH is uncharted. Our research focused on unraveling the influence of ASD on neuroinflammation mediated by NETs and the mechanisms involved. We found that increased levels of peripheral blood neutrophils post-ICH are correlated with worse prognostic outcomes. Through network pharmacology, we identified ASD as a promising therapeutic target for ICH. ASD administration significantly improved neurobehavioral performance and decreased NETs production in neutrophils. Furthermore, ASD was shown to upregulate the membrane protein NTSR1 and activate the cAMP signaling pathway, confirmed through transcriptome sequencing, western blot, and immunofluorescence. Interestingly, the NTSR1 inhibitor SR48692 significantly nullified ASD's anti-NETs effects and dampened cAMP pathway activation. Mechanistically, suppression of PKAc via H89 negated ASD's anti-NETs effects but did not affect NTSR1. Our study suggests that ASD may reduce NETs formation and neuroinflammation, potentially involving the NTSR1/PKAc/PAD4 pathway post-ICH, underlining the potential of ASD in mitigating neuroinflammation through its anti-NETs properties.

The roles of natural triterpenoid saponins against Alzheimer's disease

The aging of the world population and increasing stress levels in life are the major cause of the increased incidence of neurological disorders. Alzheimer's disease (AD) creates a huge burden on the lives and health of individuals and has become a big concern for society. Triterpenoid saponins (TS), representative natural product components, have a wide range of pharmacological bioactivities such as anti-inflammation, antioxidation, antiapoptosis, hormone-like, and gut microbiota regulation. Notably, some natural TS exhibited promising neuroprotective activity that can intervene in AD progress, especially in the early stage. Recently, studies have indicated that TS play a pronounced positive role in the prevention and treatment of AD. This review discusses the recent research on the neuroprotection of TS and proceeds to detail the action mechanisms of TS against AD, hoping to provide a reference for drug development for anti-AD.

The pathomimetic oAβ25–35 model of Alzheimer's disease: Potential for screening of new therapeutic agents

Alzheimer's disease (AD) is the most common form of dementia in the elderly, currently affecting more than 40 million people worldwide. The two main histopathological hallmarks of AD were identified in the 1980s: senile plaques (composed of aggregated amyloid-β (Aβ) peptides) and neurofibrillary tangles (composed of hyperphosphorylated tau protein). In the human brain, both Aβ and tau show aggregation into soluble and insoluble oligomers. Soluble oligomers of Aβ include their most predominant forms - Aβ_1-40 and Aβ_1-42 - as well as shorter peptides such as Aβ_25-35 or Aβ_25-35/40. Most animal models of AD have been developed using transgenesis, based on identified human mutations. However, these familial forms of AD represent less than 1% of AD cases. In this context, the idea emerged in the 1990s to directly inject the Aβ_25-35 fragment into the rodent brain to develop an acute model of AD that could mimic the disease's sporadic forms (99% of all cases). This review aims to: (1) summarize the biological activity of Aβ_25-35, focusing on its impact on the main structural and functional alterations observed in AD (cognitive deficits, APP misprocessing, tau system dysfunction, neuroinflammation, oxidative stress, cholinergic and glutamatergic alterations, HPA axis dysregulation, synaptic deficits and cell death); and (2) confirm the interest of this pathomimetic model in AD research, as it has helped identify and characterize many molecules (marketed, in clinical development, and in preclinical testing), and to the development of alternative approaches for AD prevention and therapy. Today, the Aβ_25-35 model appears as a first-intent choice model to rapidly screen the symptomatic or neuroprotective potencies of new compounds, chemical series, or innovative therapeutic strategies.

Full-length transcriptome, proteomics and metabolite analysis reveal candidate genes involved triterpenoid saponin biosynthesis in Dipsacus asperoides

Dipsacus asperoides is a traditional medicinal herb widely used in inflammation and fracture in Asia. Triterpenoid saponins from D. asperoides are the main composition with pharmacological activity. However, the biosynthesis pathway of triterpenoid saponins has not been completely resolved in D. asperoides. Here, the types and contents of triterpenoid saponins were discovered with different distributions in five tissues (root, leaf, flower, stem, and fibrous root tissue) from D. asperoides by UPLC-Q-TOF-MS analysis. The discrepancy between five tissues in D. asperoides at the transcriptional level was studied by combining single-molecule real-time sequencing and next- generation sequencing. Meanwhile, key genes involved in the biosynthesis of saponin were further verified by proteomics. In MEP and MVA pathways, 48 differentially expressed genes were identified through co-expression analysis of transcriptome and saponin contents, including two isopentenyl pyrophosphate isomerase and two 2,3-oxidosqualene β-amyrin cyclase, etc. In the analysis of WGCNA, 6 cytochrome P450s and 24 UDP- glycosyltransferases related to the biosynthesis of triterpenoid saponins were discovered with high transcriptome expression. This study will provide profound insights to demonstrate essential genes in the biosynthesis pathway of saponins in D. asperoides and support for the biosynthetic of natural active ingredients in the future.

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.

Roles of traditional chinese medicine regulating neuroendocrinology on AD treatment

The incidence of sporadic Alzheimer's disease (AD) is increasing in recent years. Studies have shown that in addition to some genetic abnormalities, the majority of AD patients has a history of long-term exposure to risk factors. Neuroendocrine related risk factors have been proved to be strongly associated with AD. Long-term hormone disorder can have a direct detrimental effect on the brain by producing an AD-like pathology and result in cognitive decline by impairing neuronal metabolism, plasticity and survival. Traditional Chinese Medicine(TCM) may regulate the complex process of endocrine disorders, and improve metabolic abnormalities, as well as the resulting neuroinflammation and oxidative damage through a variety of pathways. TCM has unique therapeutic advantages in treating early intervention of AD-related neuroendocrine disorders and preventing cognitive decline. This paper reviewed the relationship between neuroendocrine and AD as well as the related TCM treatment and its mechanism. The advantages of TCM intervention on endocrine disorders and some pending problems was also discussed, and new insights for TCM treatment of dementia in the future was provided.

Akebia saponin D protects hippocampal neurogenesis from microglia-mediated inflammation and ameliorates depressive-like behaviors and cognitive impairment in mice through the PI3K-Akt pathway

Given the ability of akebia saponin D (ASD) to protect various types of stem cells, in the present study, we hypothesized that ASD could promote the proliferation, differentiation, and survival of neural stem/precursor cells (NSPCs), even in a microglia-mediated inflammatory environment, thereby mitigating inflammation-related neuropsychopathology. We established a mouse model of chronic neuroinflammation by exposing animals to low-dose lipopolysaccharide (LPS, 0.25 mg/kg/d) for 14 days. The results showed that chronic exposure to LPS strikingly reduced hippocampal levels of PI3K and pAkt and neurogenesis in mice. In the presen of a microglia-mediated inflammatory niche, the PI3K-Akt signaling in cultured NSPCs was inhibited, promoting their apoptosis and differentiation into astrocytes, while decreasing neurogenesis. Conversely, ASD strongly increased the levels of PI3K and pAkt and stimulated NSPC proliferation, survival and neuronal differentiation in the microglia-mediated inflammatory niche in vitro and in vivo. ASD also restored the synaptic function of hippocampal neurons and ameliorated depressive- and anxiety-like behaviors and cognitive impairment in mice chronically exposed to LPS. The results from network pharmacology analysis showed that the PI3K-AKT pathway is one of the targets of ASD to against major depressive disorder (MDD), anxiety and Alzheimer’s disease (AD). And the results from molecular docking based on computer modeling showed that ASD is bound to the interaction interface of the PI3K and AKT. The PI3K-Akt inhibitor LY294002 blocked the therapeutic effects of ASD in vitro and in vivo. These results suggested that ASD protects NSPCs from the microglia-mediated inflammatory niche, promoting their proliferation, survival and neuronal differentiation, as well as ameliorating depressive- and anxiety-like behaviors and cognitive impairment by activating the PI3K-AKT pathway. Our work suggests the potential of ASD for treating Alzheimer’s disease, depression and other cognitive disorders involving impaired neurogenesis by microglia-mediated inflammation.

Asperosaponin VI ameliorates the CMS-induced depressive-like behaviors by inducing a neuroprotective microglial phenotype in hippocampus via PPAR-γ pathway

Background

The natural compound asperosaponin VI has shown potential as an antidepressant, but how it works is unclear. Here, we explored its effects on mice exposed to chronic mild stress (CMS) and the underlying molecular pathways.

Methods

Mice were exposed to CMS for 3 weeks followed by asperosaponin VI (40 mg/kg) or imipramine (20 mg/kg) for another 3 weeks. Depression-like behaviors were assessed in the forced swimming test (FST), sucrose preference test (SPT), tail suspension test (TST). Microglial phenotypes were evaluated using immunofluorescence staining, real-time quantitative PCR and enzyme-linked immunosorbent assays in hippocampus of mice. In some experiments, stressed animals were treated with the PPAR-γ antagonist GW9662 to examine its involvement in the effects of asperosaponin VI. Blockade of PPAR-γ in asperosaponin VI-treated primary microglia in the presence of lipopolysaccharide (LPS) was executed synchronously. The nuclear transfer of PPAR-γ in microglia was detected by immunofluorescence staining in vitro and in vivo. A co-cultured model of neuron and microglia was used for evaluating the regulation of ASA VI on the microglia–neuron crosstalk molecules.

Results

Asperosaponin VI ameliorated depression-like behaviors of CMS mice based on SPT, TST and FST, and this was associated with a switch of hippocampal microglia from a pro-inflammatory (iNOS⁺-Iba1⁺) to neuroprotective (Arg-1⁺-Iba1⁺) phenotype. CMS reduced the expression levels of PPAR-γ and phosphorylated PPAR-γ in hippocampus, which asperosaponin VI partially reversed. GW9662 treatment prevented the nuclear transfer of PPAR-γ in asperosaponin VI-treated microglia and inhibited the induction of Arg-1⁺ microglia. Blockade of PPAR-γ signaling also abolished the ability of asperosaponin VI to suppress pro-inflammatory cytokines while elevating anti-inflammatory cytokines in the hippocampus of CMS mice. The asperosaponin VI also promoted interactions between hippocampal microglia and neurons by enhancing CX3CL1/CX3CR1 and CD200/CD200R, and preserved synaptic function based on PSD95, CamKII β and GluA levels, but not in the presence of GW9662. Blockade of PPAR-γ signaling also abolished the antidepressant effects of asperosaponin VI in the SPT, TST and FST.

Conclusion

CMS in mice induces a pro-inflammatory microglial phenotype that causes reduced crosstalk between microglia and neuron, inflammation and synaptic dysfunction in the hippocampus, ultimately leading to depression-like behaviors. Asperosaponin VI may ameliorate the effects of CMS by inducing microglia to adopt a PPAR-γ-dependent neuroprotective phenotype.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02478-y.

Chinese Herbal Medicine Adjusting Brain Microenvironment via Mediating Central Nervous System Lymphatic Drainage in Alzheimer's Disease

Due to its complex pathogenesis and lack of effective therapeutic methods, Alzheimer's disease (AD) has become a severe public health problem worldwide. Recent studies have discovered the function of central nervous system lymphatic drainage, which provides a new strategy for the treatment of AD. Chinese herbal medicine (CHM) has been considered as a cure for AD for hundreds of years in China, and its effect on scavenging β-amyloid protein in the brain of AD patients has been confirmed. In this review, the mechanism of central nervous system lymphatic drainage and the regulatory functions of CHM on correlation factors were briefly summarized. The advances in our understanding regarding the treatment of AD via regulating the central lymphatic system with CHM will promote the clinical application of CHM in AD patients and the discovery of new therapeutic drugs.

Effects and mechanisms of natural products on Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia in elderly people with a high incidence rate and complicated pathogenesis, and causes progressive cognitive deficit and memory impairment. Some natural products and bioactive compounds from natural sources show great potential in the prevention and treatment of AD, such as apple, blueberries, grapes, chili pepper, Monsonia angustifolia, cruciferous vegetables, Herba epimedii, Angelica tenuissima, Embelia ribes, sea cucumber, Cucumaria frondosa, green tea, Puer tea, Amanita caesarea and Inonotus obliquus, via reducing amyloid beta (Aβ) deposition, decreasing Tau hyperphosphorylation, regulating cholinergic system, reducing oxidative stress, inhibiting apoptosis and ameliorating inflammation. This review mainly summarizes the effects of some natural products and their bioactive compounds on AD with the potential molecular mechanisms.

Traditional uses, phytochemistry, pharmacology, and toxicology of Akebiae Caulis and its synonyms: A review

ETHNOPHARMACOLOGICAL RELEVANCE

"Mutong" ( in Chinese, and generally known as Akebiae Caulis), which refers to a group of herbal medicines with different biological origins along history, has been used in traditional Chinese medicine for over 2000 years; it is still being frequently used in medicine. In recent decades, Akebiae Caulis has been reported to exhibit apparent toxicity.

AIM OF THIS STUDY

To clarify the plant species used as Akebiae Caulis and its synonyms, and to summarize their phytochemistry, pharmacology, and toxicology.

METHODS

Academic search engines (Google Scholar, Baidu Scholar, CNKI, Science Direct, Springer Link, SciFinder, PubMed, Web of Science, and EBSCO), ancient Chinese herbals, and modern medical monographs were used to obtain phytochemical, pharmacological, toxicological, and quality control information. Furthermore, a field survey was conducted to clarify the associated species.

RESULTS

Akebiae Caulis is derived from eight species belonging to two families. In the 2005 Pharmacopoeia of The People's Republic of China, it has been separated into two categories: Akebiae Caulis and Clematidis Armandii Caulis. Traditionally, Akebiae Caulis has been used to treat conditions such as gonorrhea, edema, and tongue sores. Pharmacological studies have demonstrated the anti-inflammatory, antitumor, antihypertensive, antibacterial, analgesic, and other properties of Akebiae Caulis. Among the species used, Aristolochiae manshuriensis Kom. (Aristolochiaceae) contains aristolochic acid that has raised concerns globally because of its nephrotoxicity.

CONCLUSIONS

Clarifying the biological origin of traditional herbal medicines is critical for their safe and effective use. The present review revealed that the biological origin of Akebiae Caulis is diverse. The traditional uses, phytochemistry, and pharmacology of Akebiae Caulis indicate that it is a useful medical resource. The diversity of its biological and pharmacological activities is associated with the presence of a large number of chemical substances, among which terpenoids are predominant. Systematic reviews on Akebiae Caulis such as this one would provide solid references for its safe use, as well as drug discovery studies in the future.

Genome-Wide Differential Methylation Profiles from Two Terpene-Rich Medicinal Plant Extracts Administered in Osteoarthritis Rats

Extracts from the plants Phlomis umbrosa and Dipsacus asperoides—which are widely used in Korean and Chinese traditional medicine to treat osteoarthritis and other bone diseases—were used to treat experimental osteoarthritis (OA) rats. Genome-wide differential methylation regions (DMRs) of these medicinal-plant-treated rats were profiled as therapeutic evidence associated with traditional medicine, and they need to be investigated further using detailed molecular research to extrapolate traditional practices to modern medicine. In total, 49 protein-encoding genes whose expression is differentially regulated during disease progression and recovery have been discovered via systematic bioinformatic analysis and have been approved/proposed as druggable targets for various bone diseases by the US food and drug administration. Genes encoding proteins involved in the PI3K/AKT pathway were found to be enriched, likely as this pathway plays a crucial role during OA progression as well as during the recovery process after treatment with the aforementioned plant extracts. The four sub-networks of PI3K/AKT were highly regulated by these plant extracts. Overall, 29 genes were seen in level 2 (51–75%) DMRs and were correlated highly with OA pathogenesis. Here, we propose that these genes could serve as targets to study OA; moreover, the iridoid and triterpenoid phytochemicals obtained from these two plants may serve as potential therapeutic agents.

Biomimetic Chromatographic Studies Combined with the Computational Approach to Investigate the Ability of Triterpenoid Saponins of Plant Origin to Cross the Blood-Brain Barrier

Biomimetic (non-cell based in vitro) and computational (in silico) studies are commonly used as screening tests in laboratory practice in the first stages of an experiment on biologically active compounds (potential drugs) and constitute an important step in the research on the drug design process. The main aim of this study was to evaluate the ability of triterpenoid saponins of plant origin to cross the blood-brain barrier (BBB) using both computational methods, including QSAR methodology, and biomimetic chromatographic methods, i.e., High Performance Liquid Chromatography (HPLC) with Immobilized Artificial Membrane (IAM) and cholesterol (CHOL) stationary phases, as well as Bio-partitioning Micellar Chromatography (BMC). The tested compounds were as follows: arjunic acid (Terminalia arjuna), akebia saponin D (Akebia quinata), bacoside A (Bacopa monnieri) and platycodin D (Platycodon grandiflorum). The pharmacokinetic BBB parameters calculated in silico show that three of the four substances, i.e., arjunic acid, akebia saponin D, and bacoside A exhibit similar values of brain/plasma equilibration rate expressed as logPSFubrain (the average logPSFubrain: -5.03), whereas the logPSFubrain value for platycodin D is -9.0. Platycodin D also shows the highest value of the unbound fraction in the brain obtained using the examined compounds (0.98). In these studies, it was found out for the first time that the logarithm of the analyte-micelle association constant (logKMA) calculated based on Foley's equation can describe the passage of substances through the BBB. The most similar logBB values were obtained for hydrophilic platycodin D, applying both biomimetic and computational methods. All of the obtained logBB values and physicochemical parameters of the molecule indicate that platycodin D does not cross the BBB (the average logBB: -1.681), even though the in silico estimated value of the fraction unbound in plasma is relatively high (0.52). As far as it is known, this is the first paper that shows the applicability of biomimetic chromatographic methods in predicting the penetration of triterpenoid saponins through the BBB.

In the presence of TGF-β1, Asperosaponin VI promotes human mesenchymal stem cell differentiation into nucleus pulposus like- cells

Background

The regeneration of nucleus pulposus (NP) cells is an effective method to prevent intervertebral disc degeneration (IVDD). In this study, we investigated the role of Asperosaponin VI (ASA VI), isolated from a traditional Chinese medicine (TCM), the root of Dipsacus asper Wall, in promoting human mesenchymal stem cell (HMSC) proliferation and differentiation into NP-like cells and explored the possible mechanism of action.

Methods

The effects of ASA VI on HMSC viability and proliferation were determined by the XTT method and EDU staining. Then, Real-time qPCR, immunocytochemistry and immunofluorescence assays were used to measure the effect of ASA VI on the expression of extracellular matrix (ECM) components, such as COL2A1, aggrecan, SOX9, KRT19, PAX1, and glycosaminoglycans (GAGs), in NP cells. In addition, Western blot assay was used to measure the expression of p-ERK1/2 and p-smad2/3.

Results

ASA VI was able to promote the proliferation and differentiation of HMSCs into NP-like cells, and the optimum concentration was 1 mg/L. Western blot assay indicated that the possible mechanism might be related to the activation of p-ERK1 / 2 and p-Smad2 / 3.

Conclusions

ASA VI can promote the proliferation and differentiation of HMSCs into NP-like cells, which can potentially be used as a treatment for IVDD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-020-03169-y.

Berberine ameliorates rats model of combined Alzheimer's disease and type 2 diabetes mellitus via the suppression of endoplasmic reticulum stress

This study is aimed to investigate the protective effect against type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD) of Berberine (BBR), and the underlying mechanism of action is explored. We established a rat model of combined AD and T2DM and used it to investigate the effect of BBR (150 mg/kg) on the course of these pathologies. The Morris water maze, biochemical analysis, hematoxylin-eosin staining, immunohistochemical study, immunofluorescent staining, TUNEL assay, RT-qPCR and western blot were used to reveal the effect of BBR on blood glucose, lipid changes, hippocampal injuries and cognitive impairment. The results showed that BBR could alleviate memory deficits, restore the disordered arrangement of nerve cells, the damage of neurons, improve TUNEL-positive cells and decrease the elevated levels of fasting blood glucose, triglyceride, total cholesterol and glycosylated serum protein levels in Alzheimer diabetic rats. Moreover, BBR treatment reduces the transcription of mRNAs and expression of proteins related to endoplasmic reticulum (ER) stress. These findings conclude that BBR can protect neurons by inhibiting the pathway of ER stress and thereby play an essential role in the preventive and therapeutic of AD and T2DM.

The antidepressant effects of asperosaponin VI are mediated by the suppression of microglial activation and reduction of TLR4/NF-κB-induced IDO expression

AIM

Indoleamine 2,3-dioxygenase 1 (IDO) is responsible for the progression of the kynurenine pathway, which has been implicated in the pathophysiology of inflammation-induced depression. It has been reported that asperosaponin VI (ASA VI) could play a neuroprotective role through anti-inflammatory and antioxidant. In this study, we examined the antidepressant effect of ASA VI in lipopolysaccharide (LPS)-treated mice and further explored its molecular mechanism by looking into the microglial kynurenine pathway.

METHODS

To generate the model, LPS (0.83 mg/kg) was administered intraperitoneally to mice. The mice received ASA VI (10 mg/kg, 20 mg/kg, 40 mg/kg, and 80 mg/kg, i.p.) 30 min before LPS injection. Depressive-like behaviors were evaluated based on the duration of immobility in the forced swim test. Microglial activation and inflammatory cytokines were detected by immunohistochemistry, real-time PCR, and ELISA. The TLR4/NF-κB signaling pathway and the expression of IDO, GluA2, and CamKIIβ were also measured by western blotting.

RESULTS

ASA VI exhibited significant antidepressant activity in the presence of LPS on immobility and latency times in the forced swim test. The LPS-induced activation of microglia and inflammatory response were inhibited by ASA VI, which showed a dose-dependent pattern. TLR4/NF-κB signaling pathway also was suppressed by ASA VI in the hippocampus and prefrontal cortex of LPS-treated mice. Furthermore, ASA VI inhibited the increase in IDO protein expression and normalized the aberrant glutamate transmission in the hippocampus and prefrontal cortex caused by LPS administration.

CONCLUSION

Our results propose a promising antidepressant effect for ASA VI possibly through the downregulation of IDO expression and normalization of the aberrant glutamate transmission. This remedying effect of ASA VI could be attributed to suppress microglia-mediated neuroinflammatory response via inhibiting the TLR4/NF-κB signaling pathway.

Pharmacodynamic and Metabolomics Studies on the Effect of Kouyanqing Granule in the Treatment of Phenol-Induced Oral Ulcer Worsened by Sleep Deprivation

Oral ulcers are the most prevalent oral mucosal diseases globally, and no specific treatment schemes are currently available due to the complexity of oral ulcer diseases. Sleep deprivation increases the risk of a deterioration in oral health. Kouyanqing Granule (KYQG) has been used for decades in China to treat inflammatory diseases of the mouth and throat associated with the hyperactivity of fire due to yin deficiency syndrome. However, the mechanisms underlying the effects of KYQG in the treatment of oral ulcers are still unclear. The aims of this study were to investigate whether KYQG treatment could attenuate the symptoms of oral ulcers worsened by sleep deprivation and identify the involved metabolic pathways. First, we conducted chemical profiling of KYQG via UPLC–MS analysis. We then combined pharmacological and metabolomics approaches in a phenol-induced rat model of oral ulcers worsened by sleep deprivation. A total of 79 compounds were initially identified. Our observations showed that KYQG treatment induced a significantly higher healing rate in oral ulcers worsened by sleep deprivation. KYQG significantly reduced the levels of 5-HT and GABA in serum, and only decreased the 5-HT level in brain tissue after phenol injury followed by sleep deprivation. Moreover, KYQG administration significantly suppressed systemic inflammation by inhibiting TNF-α, IL-1β, IL-6, IL-18, and MCP-1. Immunohistochemical analysis further revealed that KYQG inhibited IL-6 expression in buccal mucosa tissues. KYQG treatment also significantly decreased the serum levels of ACTH, CORT, IgM, and 8-OHdG. Serum metabolomics analysis showed that a total of 30 metabolites showed significant differential abundances under KYQG intervention, while metabolic pathway analysis suggested that the altered metabolites were associated with the dysregulation of eight metabolic pathways. Taken together, our results indicated that KYQG attenuates the symptoms of oral ulcers worsened by sleep deprivation probably through the regulation of the neuroimmunoendocrine system, oxidative stress levels, and tryptophan metabolism. This study also provides a novel approach for addressing the increased health risks resulting from sleep deficiency using an herbal medicine formula.

Akebia Saponin D Regulates the Metabolome and Intestinal Microbiota in High Fat Diet-Induced Hyperlipidemic Rats

Hyperlipidemia is a major component of metabolic syndrome, and regarded as one of the main risk factors causing metabolic diseases. We have developed a therapeutic drug, akebia saponin D (ASD), and determined its anti-hyperlipidemia activity and the potential mechanism(s) of action by analyzing the metabolome and intestinal microbiota. Male Sprague-Dawley rats were fed a high fat diet to induce hyperlipidemia, and then given ASD orally for 8 weeks. Lipid levels in serum were determined biochemically. Metabolites in serum, urine and feces were analyzed by UPLC-Q/TOF-MS, and the structure of the intestinal microbiota was determined by 16S rRNA sequencing. The ASD treatment significantly decreased the levels of TC, TG and LDL-c and increased the serum level of HDL-c. Metabolomics analysis indicated that the ASD treatment mainly impacted seven differential metabolites in the serum, sixteen differential metabolites in the urine and four differential metabolites in feces compared to the model group. The ASD treatment significantly changed eight bacteria at the genus level compared to the model group. In conclusion, ASD treatment can significantly alleviate HFD-induced hyperlipidemia and the hypolipidemic effect of ASD treatment is certainly associated with a systematic change in the metabolism, as well as dynamic changes in the structure of the intestinal microbiota.