Pharmacokinetic Evidence on the Contribution of Intestinal Bacterial Conversion to Beneficial Effects of Astragaloside IV, a Marker Compound of Astragali Radix, in Traditional Oral Use of the Herb

Investigation of the Metabolism of Astragaloside IV in a Puromycin-Damaged Rat Model by UPLC-Q-TOF-MS/MS Analysis

Astragaloside IV (AS-IV) has been shown to provide renal protection in various kidney injury models. However, the metabolic profile variation of AS-IV in pathological models in vivo is not well established. This study aims to explore the metabolic pathway of AS-IV in vivo in the classical puromycin aminonucleoside (PAN)-induced kidney injury in a rat model. Twelve Wistar rats were randomly divided into the AS-IV (CA) and the PAN+AS-IV (PA) treatment groups. PAN was injected by a single tail intravenous (i. v.) injection at 5 mg/100 g body weight, and AS-IV was administered intragastrically (i. g.) at 40 mg/kg for 10 days. Fecal samples of these rats were collected, and metabolites of AS-IV were detected by ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) to explore the AS-IV metabolic pathway. The metabolic differences between the AS-IV and PAN+AS-IV groups were compared. A total of 25 metabolites were detected, and deglycosylation, deoxygenation, and methyl oxidation were found to be the main metabolic pathways of AS-IV in vivo. The abundance of most of these metabolites in the PAN+AS-IV group was lower than that in the AS-IV treatment group, and differences for seven of them were statistically significant. Our study indicates that AS-IV metabolism is affected in the PAN-induced kidney injury rat model.

Alterations of gut microbiota and its correlation with the liver metabolome in the process of ameliorating Parkinson's disease with Buyang Huanwu decoction

ETHNOPHARMACOLOGICAL RELEVANCE

Buyang Huanwu decoction (BHD), a famous traditional Chinese medicine (TCM) formula, was first recorded in Qing Dynasty physician Qingren Wang's Yi Lin Gai Cuo. BHD has been widely utilized in the treatment of patients with neurological disorders, including Parkinson's disease (PD). However, the underlying mechanism has not been fully elucidated. In particular, little is known about the role of gut microbiota.

AIM OF THE STUDY

We aimed to reveal the alterations and functions of gut microbiota and its correlation with the liver metabolome in the process of improving PD with BHD.

MATERIALS AND METHODS

The cecal contents were collected from PD mice treated with or without BHD. 16S rRNA gene sequencing was performed on an Illumina MiSeq-PE250 platform, and the ecological structure, dominant taxa, co-occurrence patterns, and function prediction of the gut microbial community were analyzed by multivariate statistical methods. The correlation between differential microbial communities in the gut and differentially accumulated metabolites in the liver was analyzed using Spearman's correlation analysis.

RESULTS

The abundance of Butyricimonas, Christensenellaceae, Coprococcus, Peptococcaceae, Odoribacteraceae, and Roseburia was altered significantly in the model group, which was by BHD. Ten genera, namely Dorea, unclassified_Lachnospiraceae, Oscillospira, unidentified_Ruminococcaceae, unclassified_Clostridiales, unidentified_Clostridiales, Bacteroides, unclassified_Prevotellaceae, unidentified_Rikenellaceae, and unidentified_S24-7, were identified as key bacterial communities. According to the function prediction of differential genera, the mRNA surveillance pathway might be a target of BHD. Integrated analysis of gut microbiota and the liver metabolome revealed that several gut microbiota genera such as Parabacteroides, Ochrobactrum, Acinetobacter, Clostridium, and Halomonas, were positively or negatively correlated with some nervous system-related metabolites, such as L-carnitine, L-pyroglutamic acid, oleic acid, and taurine.

CONCLUSIONS

Gut microbiota might be a target of BHD in the process of ameliorating PD. Our findings provide novel insight into the mechanisms underlying the effects of BHD on PD and contribute to the development of TCM.

Radix Astragali decoction improves liver regeneration by upregulating hepatic expression of aquaporin-9

BACKGROUND

The therapeutic efficacy of liver injuries heavily relies on the liver's remarkable regenerative capacity, necessitating the maintenance of glycose/lipids homeostasis and oxidative eustasis during the recovery process. Astragali Radix, an herbal tonic widely used in China and many other countries, is believed to have many positive effects, including immune stimulation, nourishing, antioxidant, liver protection, diuresis, anti-diabetes, anti-cancer and expectorant. Astragali Radix is widely integrated into hepatoprotective formulas as it is believed to facilitate liver regeneration. Nevertheless, the precise molecular pharmacological mechanisms underlying this hepatoprotective effect remain elusive.

PURPOSE

To investigate the improving effects of Astragali Radix on liver regeneration and the underlying mechanisms.

METHODS

A mouse model of 70% partial hepatectomy (PHx) was employed to investigate the impact of Radix Astragali decoction (HQD) on liver regeneration. HQD was orally administered for 7 days before the PHx procedure and throughout the experiment. N-acetylcysteine (NAC) was used as a positive control for liver regeneration. Liver regeneration was assessed by evaluating the liver-to-body weight ratio (LW/BW) and the expression of representative cell proliferation marker proteins. Oxidative stress and glucose metabolism were analyzed using biochemical assays, Western blotting, dihydroethidium (DHE) fluorescence, and periodic acid-Schiff (PAS) staining methods. To understand the role of AQP9 as a potential molecular target of HQD in promoting liver regeneration, td-Tomato-tagged AQP9 transgenic mice (AQP9-RFP) were employed to determine the expression pattern of AQP9 protein. AQP9 knockout mice (AQP9-/-) were used to assess the specific targeting of AQP9 in the promotion of liver regeneration by HQD.

RESULTS

HQD significantly upregulated hepatic AQP9 expression, alleviated liver injury and promoted liver regeneration in wild-type (AQP9+/+) mice after 70% PHx. However, the beneficial impact of HQD on liver regeneration was absent in AQP9 gene knockout (AQP9-/-) mice. Moreover, HQD facilitated the uptake of glycerol by hepatocytes, enhanced gluconeogenesis, and concurrently reduced H2O2 content and oxidative stress levels in AQP9+/+ but not AQP9-/- mouse livers. Additionally, main active substance of Radix Astragali, astragaloside IV (AS-IV) and cycloastragenol (CAG), demonstrated substantial upregulation of AQP9 expression and promoted liver regeneration in AQP9+/+ but not AQP9-/- mice.

CONCLUSION

This study is the first to demonstrate that Radix Astragali and its main active constituents (AS-IV and CAG) improve liver regeneration by upregulating the expression of AQP9 in hepatocytes to increase gluconeogenesis and reduce oxidative stress. The study revealed novel molecular pharmacological mechanisms of Radix Astragali and provided a promising therapeutic target of liver diseases.

Potential Impact of Bioactive Compounds as NLRP3 Inflammasome Inhibitors: An Update

The inflammasome NLRP3 comprises a caspase recruitment domain, a pyrin domain containing receptor 3, an apoptosis-linked protein like a speck containing a procaspase-1, and an attached nucleotide domain leucine abundant repeat. There are a wide variety of stimuli that can activate the inflammasome NLRP3. When activated, the protein NLRP3 appoints the adapter protein ASC. Adapter ASC protein then recruits the procaspase-1 protein, which causes the procaspase- 1 protein to be cleaved and activated, which induces cytokines. At the same time, abnormal activation of inflammasome NLRP3 is associated with many diseases, such as diabetes, atherosclerosis, metabolic syndrome, cardiovascular and neurodegenerative diseases. As a result, a significant amount of effort has been put into comprehending the mechanisms behind its activation and looking for their specific inhibitors. In this review, we primarily focused on phytochemicals that inhibit the inflammasome NLRP3, as well as discuss the defects caused by NLRP3 signaling. We conducted an in-depth research review by searching for relevant articles in the Scopus, Google Scholar, and PubMed databases. By gathering information on phytochemical inhibitors that block NLRP3 inflammasome activation, a complicated balance between inflammasome activation or inhibition with NLRP3 as a key role was revealed in NLRP3-driven clinical situations.

Neurotrophic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins. Small-molecular-weight natural products, which have been used in dietary functional foods or in traditional medicines over the course of human history, have a great potential for the development of new therapeutic agents against neurodegenerative diseases such as Alzheimer's disease. In this contribution, a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection are described, and a focus is made on the chemistry and biology of several neurotrophic natural products.

Study on the Biotransformation and Activities of Astragalosides from Astragali Radix In Vitro and In Vivo

Astragalosides (AGs), as one of the main active ingredients in Astragali Radix (AR), have a series of biological activities. Previous studies have only qualitatively identified the metabolites of AGs in AR, resulting in a lack of quantification. In the present study, the original material was selected from 12 origins based on the levels of 4 AGs by high-performance liquid chromatography (HPLC). The prototype components and metabolites of total AGs (TAGs) in feces, urine, and plasma samples of rats were thoroughly screened and characterized by ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). The fermentation reaction and metabolites were verified by human fecal TAG fermentation in vitro. The metabolites of AG I, II, and IV transformed by human feces at different times were identified using UHPLC-HRMS, and the partial metabolites were quantified by HPLC. Furthermore, the anti-inflammatory and antioxidant activities of the metabolites were evaluated based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells in vitro. In total, 13 AGs and 170 metabolites were identified in TAGs as well as in the plasma, urine, and feces of Sprague-Dawley (SD) rats by UHPLC-HRMS, including 28, 36, and 170 metabolites in the plasma, urine, and feces, respectively. The metabolites included the products of deglycosylation, demethylation, hydroxylation, glucuronidation, sulfation, and cysteine-binding reactions. Moreover, the TAG fermentation results in vitro showed great similarity. The human fecal incubation experiments for AG I, II, and IV demonstrated that the metabolic reaction of TAGs mainly occurred in intestinal feces and that deglycosylation, demethylation, and hydroxylation were the main pathways of their metabolism. HPLC quantitative analysis of the transformation solution at different time points showed that AGs were transformed into secondary glycosides [cycloastragenol-6-glucoside (CAG-6-glucoside)] and aglycones [cycloastragenol (CAG)] through a deglycosylation reaction. Analysis of the pharmacological activity showed that the anti-inflammatory and antioxidant activities of the metabolites were associated with the levels of the corresponding aglycones. Further, metabolic profiles of the TAGs were constructed. Overall, this study revealed the metabolic process of AGs in the intestine, providing guidance for the metabolism and pharmacological effects of other saponins.

Review on the protective mechanism of astragaloside IV against cardiovascular diseases

Cardiovascular disease is a global health problem. Astragaloside IV (AS-IV) is a saponin compound extracted from the roots of the Chinese herb Astragalus. Over the past few decades, AS-IV has been shown to possess various pharmacological properties. It can protect the myocardium through antioxidative stress, anti-inflammatory effects, regulation of calcium homeostasis, improvement of myocardial energy metabolism, anti-apoptosis, anti-cardiomyocyte hypertrophy, anti-myocardial fibrosis, regulation of myocardial autophagy, and improvement of myocardial microcirculation. AS-IV exerts protective effects on blood vessels. For example, it can protect vascular endothelial cells through antioxidative stress and anti-inflammatory pathways, relax blood vessels, stabilize atherosclerotic plaques, and inhibit the proliferation and migration of vascular smooth muscle cells. Thus, the bioavailability of AS-IV is low. Toxicology indicates that AS-IV is safe, but should be used cautiously in pregnant women. In this paper, we review the mechanisms of AS-IV prevention and treatment of cardiovascular diseases in recent years to provide a reference for future research and drug development.

A novel microbial and hepatic biotransformation-integrated network pharmacology strategy explores the therapeutic mechanisms of bioactive herbal products in neurological diseases: the effects of Astragaloside IV on intracerebral hemorrhage as an example

BACKGROUND

The oral bioavailability and blood-brain barrier permeability of many herbal products are too low to explain the significant efficacy fully. Gut microbiota and liver can metabolize herbal ingredients to more absorbable forms. The current study aims to evaluate the ability of a novel biotransformation-integrated network pharmacology strategy to discover the therapeutic mechanisms of low-bioavailability herbal products in neurological diseases.

METHODS

A study on the mechanisms of Astragaloside IV (ASIV) in treating intracerebral hemorrhage (ICH) was selected as an example. Firstly, the absorbed ASIV metabolites were collected by a literature search. Next, the ADMET properties and the ICH-associated targets of ASIV and its metabolites were compared. Finally, the biotransformation-increased targets and biological processes were screened out and verified by molecular docking, molecular dynamics simulation, and cell and animal experiments.

RESULTS

The metabolites (3-epi-cycloastragenol and cycloastragenol) showed higher bioavailability and blood-brain barrier permeability than ASIV. Biotransformation added the targets ASIV in ICH, including PTK2, CDC42, CSF1R, and TNF. The increased targets were primarily enriched in microglia and involved in cell migration, proliferation, and inflammation. The computer simulations revealed that 3-epi-cycloastragenol bound CSF1R and cycloastragenol bound PTK2 and CDC42 stably. The In vivo and in vitro studies confirmed that the ASIV-derived metabolites suppressed CDC42 and CSF1R expression and inhibited microglia migration, proliferation, and TNF-α secretion.

CONCLUSION

ASIV inhibits post-ICH microglia/macrophage proliferation and migration, probably through its transformed products to bind CDC42, PTK2, and CSF1R. The integrated strategy can be used to discover novel mechanisms of herbal products or traditional Chinses medicine in treating diseases.

Shengmai san-derived compound prescriptions: A review on chemical constituents, pharmacokinetic studies, quality control, and pharmacological properties

BACKGROUND

Shengmai San Formula (SMS), composed of Ginseng Radix et Rhizoma, Ophiopogon Radix and Schisandra chinensis Fructus, was a famous formula in Tradition Chinese Medicine (TCM). With the expansion of clinical applications, SMS was developed to different dosage forms, including Shengmai Yin Oral liquid (SMY), Shengmai Capsule (SMC), Shengmai Granule (SMG), Shengmai Injection (SMI) and Dengzhan Shengmai Capsule (DZSMC). These above SMS-derived compound prescriptions (SSCPs) play an important role in the clinical treatment. This review is aimed to providing a comprehensive perspective of SSCP.

METHODS

The relevant literatures were collected from classical TCM books and a variety of databases, including PubMed, Google Scholar, Science Direct, Springer Link, Web of Science, China National Knowledge Infrastructure, and Wanfang Data.

RESULTS

The chemical constituents of SSCPs, arrived from the individual medicinal materials including Ginseng Radix et Rhizoma, Ophiopogon Radix, Schisandra chinensis Fructus, Erigerontis Herba, were firstly summarized respectively. Then the pharmacokinetics studies, quality control, and pharmacological properties of SSCPs were all reviewed. The active compounds, pharmacokinetics characterizes, quality control markers, the effects and mechanisms of pharmacology of the different dosage forms of SSCPs were summarized. Furthermore, the research deficiencies of SSCPs and an innovative research paradigm for Chinese materia medica (CMM) formula were proposed.

CONCLUSIONS

SMS, as a famous CMM formula, has great values in drug research and in clinical treatment especially for cardiocerebrovascular diseases. This article firstly make a comprehensive and systematic review on SMS.

The construction of oligonucleotide-cycloastragenol and the renoprotective effect study

Traditional Chinese Medicine (TCM) provides unique therapeutic effects for many diseases with identified efficacy during long practice. Astragalus Membranaceus (AM) is the Chinese herbal applied for kidney injury in the clinic, but it remains challenging to further enhance the efficacy. Cycloastragenol (CAG) is the ingredient isolated from AM with poor water solubility, which has shown a renoprotective effect. Herein we designed and synthesized the corresponding solid-phase module of CAG, from which CAG as a pharmaceutical element was incorporated into oligonucleotides (ON) as an ON-CAG conjugate in a programmable way by a DNA synthesizer. Cell viability study demonstrated that ON-CAG conjugate remains similar renoprotective effect as that of CAG, which efficiently recovers the activity of HK-2 cells pretreated with cisplatin. Similarly, in the renal cells treated with the conjugate, the biomarkers of kidney injury such as KIM-1 and IL-18 are downregulated, and cytokines are reduced as treated with anti-inflammatory agents. Overall, we have managed to incorporate a hydrophobic ingredient of TCM into ON and demonstrate the oligonucleotide synthesis technology as a unique approach for the mechanism study of TCM, which may facilitate the discovery of new therapeutics based on TCM.

Analysis of Astragaloside IV metabolism to Cycloastragenol in human gut microorganism, bifidobacteria, and lactic acid bacteria

This study investigated different gut bacteria in an anaerobic environment to identify specific candidates that could transform astragaloside IV (AIV) to cycloastragenol (CA). Two representative gut microbes, lactic acid bacteria (LAB) and bifidobacteria, could metabolize AIV to CA. Multiple screenings showed two metabolic pathways to metabolize AIV in two groups of bacteria. LAB metabolized AIV initiated by removing the C-6 glucose, whereas bifidobacteria indicated the initial removal of C-3 xylose. The final products differed between the two groups as bifidobacteria showed the production of CA, whereas LAB demonstrated preferential production of 20R, 24S-epoxy-6α, -16β, -25-trihydroxy-9, -19-cycloartan-3-one (CA-2H).

Impact of Gut Microbiota on the Pharmacokinetics of Glycyrrhizic Acid in Yokukansan, a Kampo Medicine

Individual differences in gut microbiota can affect the pharmacokinetics of drugs. Yokukansan is a traditional Japanese kampo medicine used to treat peripheral symptoms of dementia and delirium. A study examining the pharmacokinetics of the components of yokukansan reported large individual differences in the pharmacokinetics of glycyrrhizic acid (GL). It is known that GL is metabolized by intestinal bacteria to glycyrrhetinic acid (GA), which is absorbed in the gastrointestinal tract. Thus, the gut microbiota may affect GL pharmacokinetics. We aimed to clarify the relationship between the gut microbiota composition and pharmacokinetics of GL in yokukansan. Mice were orally administered yokukansan, following the administration of various antibiotics, and the plasma concentration of GA and composition of gut microbiota were measured. The GA plasma concentration was low in mice treated with amoxicillin and vancomycin. The composition of gut microbiota revealed a different pattern from that of the control group. Mice with low plasma levels of GA had lower levels of the phylum Bacteroides and Firmicutes. Additionally, bacteria, such as those belonging to the genera Parabaceroides, Bacteroides, Ruminococcus and an unknown genus in families Lachnospiraceae and Ruminococcaceae, exerted positive correlations between the gene copies and plasma GA levels. These bacteria may contribute to the absorption of GA in the gastrointestinal tract, and multiple bacteria may be involved in GL pharmacokinetics. The pharmacokinetics of GL may be predicted by evaluating the composition of gut bacteria, rather than by evaluating the amount of a single bacterium.

Cycloastragenol, a Triterpenoid Saponin, Regulates Oxidative Stress, Neurotrophic Dysfunctions, Neuroinflammation and Apoptotic Cell Death in Neurodegenerative Conditions

Here, we have unveiled the effects of cycloastragenol against Aβ (Amyloid-beta)-induced oxidative stress, neurogenic dysfunction, activated mitogen-activated protein (MAP) kinases, and mitochondrial apoptosis in an Aβ-induced mouse model of Alzheimer's disease (AD). The Aβ-induced mouse model was developed by the stereotaxic injection of amyloid-beta (5 μg/mouse/intracerebroventricular), and cycloastragenol was given at a dose of 20 mg/kg/day/p.o for 6 weeks daily. For the biochemical analysis, we used immunofluorescence and Western blotting. Our findings showed that the injection of Aβ elevated oxidative stress and reduced the expression of neurogenic markers, as shown by the reduced expression of brain-derived neurotrophic factor (BDNF) and the phosphorylation of its specific receptor tropomyosin receptor kinase B (p-TrKB). In addition, there was a marked reduction in the expression of NeuN (neuronal nuclear protein) in the Aβ-injected mice brains (cortex and hippocampus). Interestingly, the expression of Nrf2 (nuclear factor erythroid 2-related factor 2), HO-1 (heme oxygenase-1), p-TrKB, BDNF, and NeuN was markedly enhanced in the Aβ + Cycloastragenol co-treated mice brains. We have also evaluated the expressions of MAP kinases such as phospho c-Jun-N-terminal kinase (p-JNK), p-38, and phospho-extracellular signal-related kinase (ERK1/2) in the experimental groups, which suggested that the expression of p-JNK, p-P-38, and p-Erk were significantly upregulated in the Aβ-injected mice brains; interestingly, these markers were downregulated in the Aβ + Cycloastragenol co-treated mice brains. We also checked the expression of activated microglia and inflammatory cytokines, which showed that cycloastragenol reduced the activated microglia and inflammatory cytokines. Moreover, we evaluated the effects of cycloastragenol against mitochondrial apoptosis and memory dysfunctions in the experimental groups. The findings showed significant regulatory effects against apoptosis and memory dysfunction as revealed by the Morris water maze (MWM) test. Collectively, the findings suggested that cycloastragenol regulates oxidative stress, neurotrophic processes, neuroinflammation, apoptotic cell death, and memory impairment in the mouse model of AD.

Major bioactive chemical compounds in Astragali Radix samples from different vendors vary greatly

The worldwide traditional Chinese medicine (TCM) herbs sales figures have increased considerably to 50 billion US$ (2018). Astragali Radix (AR) is amongst the most often sold TCM herbs; sales in the European Union (EU) need European Medicines Agency (EMA) approval. However, comparisons of characteristic bioactive molecules concentrations in AR from different EU vendors are lacking. This study uses liquid chromatography-tandem mass spectrometry (LC-MS/MS) with standard addition to evaluate the influence of different sample and preparation types and ammonia treatment on bioactive molecules concentrations in AR. We also compare AR samples from different EU-vendors. Astragaloside IV (AG-IV), ononin and calycosin 7-O-β-D-glucoside concentrations were higher in root powder samples when extracted with boiled water than with ultrasonication using 70% methanol. AG-IV content was by far the highest in granulates from vendor 1 (202 ± 35 μg/g) but very low in hydrophilic concentrates from vendor 1 (32 ± 7 μg/g) and granulates from vendor 4 (36 ± 3 μg/g). Ammonia-treatment significantly increased AG-IV concentrations in all samples (e.g., to 536 ± 178 μg/g in vendor 1 granulates). Comparable effects were found for most other bioactive molecules. AG-IV and other bioactive molecules concentrations differed strongly depending on sample types, extraction processes, ammonia treatment-or-not and especially between different vendors samples. Ammonia-treatment is debatable, as it is supposed to convert other astragalosides, to AG-IV. The results indicate that routine quantitative analysis of major bioactive compounds present in AR, helps in quality control of AR and to guarantee the quality of commercial products.

Quantification by LC-MS/MS of astragaloside IV and isoflavones in Astragali radix can be more accurate by using standard addition

INTRODUCTION

Astragali radix (AR), the root of Astragalus, is an important medical herb widely used in traditional Chinese medicine. Bioactive components include isoflavones and a unique class of triterpenoid saponins (named astragalosides).

OBJECTIVES

Accurate measurement of bioactive components, especially astragaloside IV, is necessary for confirming AR authenticity, quality control and future medical research.

METHODOLOGY

Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) is a suitable technique but suffers from ion suppression effects due to sample matrix. This can be corrected by using isotopic labelled internal standards, but these are not available for many phytochemicals. We explored the use of standard addition to circumvent this issue.

RESULTS

LC-MS/MS and liquid chromatography coupled with ultraviolet (LC-UV) detection provided linear calibration curves (R² > 0.99). LC-MS/MS provided superior selectivity and detection limits below 10 ng/mL, which was 2-3 magnitudes lower than LC-UV detection. Precision and accuracy were overall improved by using LC-MS/MS with diluted sample extracts, resulting in an inter series coefficient of variation (CV) of 12% or less and mean recovery estimates in the 85-115% range. LC-MS/MS quantification by standard addition resulted in significantly higher concentrations of astragaloside IV measured in the samples. Concentrations calculated by standard addition were unaffected by large variation in signal response caused by matrix effects, independent of variation in slope of the standard addition curves.

CONCLUSION

Sample dilution was helpful but not sufficient for reducing effects of ion suppression. We have shown that LC-MS/MS quantification by standard addition can be a powerful approach for accurate measurement of phytochemicals in the absence of isotopic labelled internal standards.

Berberine improves colitis by triggering AhR activation by microbial tryptophan catabolites

Inflammatory bowel diseases (IBD) are kind of recurrent inflammatory issues that occur in the gastrointestinal tract, and currently clinical treatment is still unideal due to the complex pathogenesis of IBD. Basically, gut barrier dysfunction is triggered by gut microbiota dysbiosis that is closely associated with the development of IBD, we thus investigated the therapeutic capacity of berberine (BBR) to improve the dysregulated gut microbiota, against IBD in rats, using a combinational strategy of targeted metabolomics and 16 s rDNA amplicon sequencing technology. Expectedly, our data revealed that BBR administration could greatly improve the pathological phenotype, gut barrier disruption, and the colon inflammation in rats with dextran sulfate sodium (DSS)-induced colitis. In addition, 16S rDNA-based microbiota analysis demonstrated that BBR could alleviate gut dysbiosis in rats. Furthermore, our targeted metabolomics analysis illustrated that the levels of microbial tryptophan catabolites in the gastrointestinal tract were significantly changed during the development of the colitis in rats, and BBR treatment can significantly restore such changes of the tryptophan catabolites accordingly. At last, our in vitro mechanism exploration was implemented with a Caco-2 cell monolayer model, which verified that the modulation of the dysregulated gut microbiota to change microbial metabolites coordinated the improvement effect of BBR on gut barrier disruption in the colitis, and we also confirmed that the activation of AhR induced by microbial metabolites is indispensable to the improvement of gut barrier disruption by BBR. Collectively, BBR has the capacity to treat DSS-induced colitis in rats through the regulation of gut microbiota associated tryptophan metabolite to activate AhR, which can greatly improve the disrupted gut barrier function. Importantly, our finding elucidated a novel mechanism of BBR to improve gut barrier function, which holds the expected capacity to promote the BBR derived drug discovery and development against the colitis in clinic setting.

Simultaneous determination of calycosin, prim-O-glucosylcimifugin, and paeoniflorin in rat plasma by HPLC-MS/MS: application in the pharmacokinetic analysis of HQCF

Objective

This study aimed to develop and validate a high-performance liquid chromatography–tandem mass spectrometry method to simultaneously determine three bioactive components of the Huangqi Chifeng decoction (HQCF) in rat plasma.

Methods

Taxol was used as an internal standard in the developed method. Chromatographic separation was performed on a C₁₈ column using a gradient elution with 0.1% formic acid in acetonitrile (v/v) and 0.1% formic acid in water (v/v) as the mobile phases at a flow rate of 0.4 mL·minute⁻¹. All compounds were monitored via selected reaction monitoring with an electrospray ionization source.

Results

The lower limits of quantification of paeoniflorin, calycosin, and prim-O-glucosylcimifugin were 15.0, 0.75, and 0.75 ng·mL⁻¹, respectively. The calibration curves indicated optimal linearity (r > 0.99) across the concentration ranges. The specificity, precision, accuracy, recovery, matrix effect, and stability of the method were validated. This method was successfully applied in a pharmacokinetics study of the three compounds in rat plasma.

Conclusion

The pharmacokinetics results provide insights into the mechanisms of HQCF in vivo and its future clinical application.

Proteomic Analysis of Proteins Associated with Inhibition of Pseudomonas aeruginosa Resistance to Imipenem Mediated by the Chinese Herbal Medicine Qi Gui Yin

Objective: Antibiotic resistance of Pseudomonas aeruginosa (PA) that lowers the effectiveness of current treatments for pneumonia is a growing problem. Qi Gui Yin is a Chinese herbal medicine that has been used to improve the efficacy of antibiotic therapy against antibiotic-resistant bacteria. This study aimed to elucidate the mechanism by which Qi Gui Yin inhibits antibiotic resistance of PA. Methods: Active components of Qi Gui Yin were analyzed by chromatography. Isobaric Tags for Relative and Absolute Quantification (iTRAQ) technology was used to compare protein expression profiles of PA strains cultured in serum from rats that were and were not treated with Qi Gui Yin. Quantitative polymerase chain reaction (qPCR) analysis was performed to detect gene expression changes. Results: Proteomic analysis identified 76 differentially expressed proteins between PA strains cultured in serum from rats that were or were not treated with Qi Gui Yin. Bioinformatics analysis revealed that the largest number of differentially expressed proteins were associated with resistance mechanisms such as quorum sensing, bacterial biofilm formation, and active pumping. In addition, qPCR analysis confirmed that downregulation of iscU and arcA gene expression was associated with Qi Gui Yin treatment. Conclusions: Serum from Qi Gui Yin-treated rats could effectively inhibit antibiotic resistance of PA. Chlorogenic acid and astragaloside IV are the main components of Qi Gui Yin, which may mediate inhibition of antibiotic resistance. Our findings provide new insights into strategies involving Chinese herbal medicine that can be used to treat pneumonia caused by antibiotic-resistant bacteria.

Cycloastragenol upregulates SIRT1 expression, attenuates apoptosis and suppresses neuroinflammation after brain ischemia

Cycloastragenol (CAG) is the active form of astragaloside IV isolated from Astragalus Radix, which displays multiple pharmacological effects. Silent information regulator 1 (SIRT1), a class III histone deacetylase, has been shown to play an important role in neuroprotection against cerebral ischemia. In this study, we investigated whether CAG protected against ischemic brain injury and, if so, whether the beneficial effects were associated with the regulation of SIRT1 in the ischemic brain. Mice were subjected to 45 min of middle cerebral artery occlusion (MCAO) followed by reperfusion. CAG (5, 10, 20 mg/kg) was injected intraperitoneally at the onset of reperfusion, 12 h later and then twice daily for up to three days. CAG dose-dependently reduced brain infarct volume, significantly ameliorated functional deficits, and prevented neuronal cell loss in MCAO mice. Meanwhile, CAG significantly reduced matrix metalloproteinase-9 activity, prevented tight junction degradation and subsequently ameliorated blood-brain barrier disruption. Moreover, CAG significantly upregulated SIRT1 expression in the ischemic brain but did not directly activate its enzymatic activity. Concomitant with SIRT1 upregulation, CAG reduced p53 acetylation and the ratio of Bax to Bcl-2 in the ischemic brain. CAG also inhibited NF-κB p65 nuclear translocation. As a result, CAG suppressed the mRNA expression of pro-inflammatory cytokines, including TNF-α and IL-1β, and inhibited the activation of microglia and astrocytes in the ischemic brain. Our findings suggest that CAG is neuroprotective against ischemic brain injury in mice and that its beneficial effect may involve SIRT1 upregulation and the inhibition of apoptosis and neuroinflammation in the ischemic brain.

Comparison of the Gut Microbiota Between Pulsatilla Decoction and Levofloxacin Hydrochloride Therapy on Escherichia coli Infection

Gut microbiota serves as a critical indicator for gut health during treatment of pathogenic bacterial infection. Both Pulsatilla Decoction (abbreviated to PD, a traditional Chinese medicine compound) and Levofloxacin Hydrochloride (LVX) were known to have therapeutic effects to intestinal infectious disease. However, the changes of gut microbiota after PD or LVX treatment remain unclear. Herein, this work aimed to investigate the changes of intestinal flora after PD or LVX therapy of Escherichia coli infection in rats. Results revealed that PD exhibited a valid therapeutic approach for E. coli infection via the intestinal protection, as well as the inhibited release of IL-8 and ICAM-1. Besides, PD was beneficial to rebuild the gut microbiota via restoring Bacteroidetes spp in the composition of the gut microbiota. Comparatively, LVX treatment promoted the infection and ravaged gut microbiota by significantly decreasing Bacteroidetes and increasing Firmicutes. These findings not only highlight the mechanism of Chinese herbal formula, but extend the application of PD as veterinary medicine, feed additive and pre-mixing agent for improving the production of animal derived foods.

Comprehensive investigation of mechanism and effective ingredients of Fangji Huangqi Tang by serum pharmacochemistry and network pharmacology

Fangji Huangqi Tang (FHT), has been reported to show effects on nephrotic syndrome, but its mechanism of action and bioactive components have not yet been determined. In this study, a method using UPLC-HRMS/MS was established for the detection and identification of the chemical constituents and metabolites absorbed into the blood. Absorbed components in serum were then used for the network pharmacology analysis to deduce the mechanism and effective components. A total of 86 compounds were identified or tentatively characterized. Based on the same instrumental conditions, 85 compounds were found in rat serum after oral administration of FHT, including 22 prototypes and 63 metabolites. Network pharmacology analysis showed that absorbed components, such as (3R)-2',3',4',7-tetrahydroxyisoflavan, astrapterocarpan, cycloastragenol, 7,2'-dihydroxy-3',4'-dimethoxyisoflavan, astragaloside IV, astrapterocarpan glucoside and glycyrrhetinic acid, could be responsible for the pharmacological activity of nephrotic syndrome by regulating the VEGF signaling pathway, focal adhesion and MAPK signaling pathway. Furthermore, the pathway-target network showed that the MAPK1, AKT2 and CDC42 were involved in the signal pathways above. This study provides a scientific basis for the mechanism and effective ingredients of FHT.

Ophiopogon Polysaccharide Promotes the In Vitro Metabolism of Ophiopogonins by Human Gut Microbiota

Gut microbiota play an important role in metabolism of intake saponins, and parallelly, the polysaccharides deriving from herbal products possess effects on gut microbiota. Ophiopogonis Radix is a common Chinese herb that is popularly used as functional food in China. Polysaccharide and steroidal saponin, e.g., ophiopogonin, mainly ophiopogonin D (Oph-D) and ophiopogonin D' (Oph-D'), are the major constituents in this herb. In order to reveal the role of gut microbiota in metabolizing ophiopogonin, an in vitro metabolism of Oph-D and Oph-D' by human gut microbiota, in combination with or without Ophiopogon polysaccharide, was conducted. A sensitive and reliable UPLC-MS/MS method was developed to simultaneously quantify Oph-D, Oph-D' and their final metabolites, i.e., ruscogenin and diosgenin in the broth of microbiota. An elimination of Oph-D and Oph-D' was revealed in a time-dependent manner, as well as the recognition of a parallel increase of ruscogenin and diosgenin. Ophiopogon polysaccharide was shown to stimulate the gut microbiota-induced metabolism of ophiopogonins. This promoting effect was further verified by increased activities of β-D-glucosidase, β-D-xylosidase, α-L-rhamnosidase and β-D-fucosidase in the broth. This study can be extended to investigate the metabolism of steroidal saponins by gut microbiota when combined with other herbal products, especially those herbs enriched with polysaccharides.

Comparative pharmacokinetic study on three formulations of Astragali Radix by an LC-MS/MS method for determination of formononetin in human plasma

Astragali Radix (AR) is a widely used traditional Chinese medicine for healing the cardiovascular, liver and immune systems. Recently, superfine pulverizing technology has been applied to developing novel formulations to improve bioavailability of the active constituents in herbs, such as ultrafine granular powder of AR. In this study, a universal and sensitive quantitative method based on LC-MS/MS was employed for determining formononetin, the main flavonoid in AR, in human plasma for comparative pharmacokinetics of three oral formulations of AR. Formononetin and IS (quercetin) were extracted by ethyl acetate from human plasma and were separated on a C₁₈ column with a mobile phase consisting of acetonitrile and 0.1% formic acid. Positive-ion electrospray-ionization mode was applied in mass spectrometric detection. The quantitative method was validated with regards to selectivity, linearity, accuracy and precision, matrix effect, extraction recovery and stability, and was applied to comparing the pharmacokinetics of ultrafine granular powder (UGP), ultrafine powder (UP) and traditional decoction pieces (TDP) of AR after oral administration. The peak concentration and areas under the concentration-time curve of formononetin in UGP and UP were significantly higher than those of TDP. UGP and UP could significantly improve the bioavailability of AR in human compared with TDP after oral administration.

A Systematic Review of Phytochemistry, Pharmacology and Pharmacokinetics on Astragali Radix: Implications for Astragali Radix as a Personalized Medicine

Astragali radix (AR) is one of the most widely used traditional Chinese herbal medicines. Modern pharmacological studies and clinical practices indicate that AR possesses various biological functions, including potent immunomodulation, antioxidant, anti-inflammation and antitumor activities. To date, more than 200 chemical constituents have been isolated and identified from AR. Among them, isoflavonoids, saponins and polysaccharides are the three main types of beneficial compounds responsible for its pharmacological activities and therapeutic efficacy. After ingestion of AR, the metabolism and biotransformation of the bioactive compounds were extensive in vivo. The isoflavonoids and saponins and their metabolites are the major type of constituents absorbed in plasma. The bioavailability barrier (BB), which is mainly composed of efflux transporters and conjugating enzymes, is expected to have a significant impact on the bioavailability of AR. This review summarizes studies on the phytochemistry, pharmacology and pharmacokinetics on AR. Additionally, the use of AR as a personalized medicine based on the BB is also discussed, which may provide beneficial information to achieve a better and more accurate therapeutic response of AR in clinical practice.

Determination of a astragaloside IV derivative LS-102 in plasma by ultra-performance liquid chromatography-tandem mass spectrometry in dog plasma and its application in a pharmacokinetic study

BACKGROUND

Astragalosidic acid (LS-102) is a new water-soluble derivative of astragaloside IV - a major effective component isolated from the Chinese herb Astragali Radix. Our previous study showed that LS-102 exhibited potent cardiovascular activity.

PURPOSE

The objective of this study was to investigate the pharmacokinetic properties of LS-102 after single-dose, oral administration in beagle dogs by developing and validating an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method.

METHOD AND RESULT

The chromatographic separation was performed on a Acquity HSS C₁₈ column (100 mm × 2.1 mm, 1.8 µm) by a gradient elution using a mobile phase consisting of water and acetonitrile at a flow rate of 0.35 ml/min. The analytes were detected with a triple quadrupole tandem mass spectrometry in multiple reaction monitoring mode. Method validation revealed a wide linearity over the range of 2.0-10,000 ng/ml together with satisfactory intra- and inter-day precision, accuracy, and recovery. Stability testing showed that LS-102 spiked into dog plasma was stable for 4 h at room temperature, for up to 2 weeks at -80 °C, and during three freeze-thaw cycles. The method was effectively and successfully applied to the pharmacokinetics of LS-102 after oral administration (5, 10 and 20 mg/kg) to beagle dogs. Peak plasma concentrations are attained within approximately 2 h after oral administration with a half-life ranging from 1.55 h to 4.49 h. The plasma concentration-time curve of LS-102 after oral administration presents the phenomenon of a double-peak absorption phase. The peak concentration and area under the concentration-time curve of LS-102 seemed to increase with the increasing doses proportionally, that suggesting linear pharmacokinetics in dogs. Meanwhile, the doxorubicin (Dox)-injured H9c2 cell model was prepared by incubating the cells in 1 µM Dox for 24 h. MTT assay and LDH release measurement showed that LS-102 protected against Dox-induced cardiomyocyte death.

CONCLUSION

The obtained results may help to guide the further pre-clinical research of LS-102 as a potentially novel cardioprotective agent.

Inhibitory effects of cycloastragenol on abdominal aortic aneurysm and its related mechanisms

BACKGROUND AND PURPOSE

Abdominal aortic aneurysm (AAA) is a degenerative disease affecting human health, but there are no safe and effective medications for AAA therapy. Cycloastragenol (CAG), derived from Astragali Radix, has various pharmacological effects. However, whether CAG can protect against AAA remains elusive. In this study, we investigated whether CAG has an inhibitory effect on AAA and its related mechanism.

EXPERIMENTAL APPROACH

The AAA mouse model was induced by incubating the abdominal aorta with elastase. CAG was administered by gavage at different doses beginning on the same day or 14 days after inducing AAA to explore its preventive or therapeutic effects respectively. The preventive effects of CAG on AAA were verified in another AAA mouse model induced by angiotensin II in ApoE-/- mouse. In vitro experiments were implemented on rat vascular smooth muscle cells (VSMCs) stimulated by TNF-α.

KEY RESULTS

Compared to the control AAA model group, CAG (125 mg·kg-1 body weight day-1 ) reduced the incidence of AAA, the dilatation of aorta and elastin degradation in media in both mouse models of AAA. CAG suppressed the inflammation, oxidation, phenotype switch and apoptosis in TNF-α-stimulated VSMCs, ameliorated the expression and activity of MMPs and decreased the activation of the ERK/JNK signalling pathway. CAG also inhibited the degradation of elastin in TNF-α-stimulated VSMCs.

CONCLUSION AND IMPLICATIONS

CAG presents protective effects against AAA through down-regulation of the MAPK signalling pathways and thus attenuates inflammation, oxidation, VSMC phenotype switch and apoptosis and the expression of MMPs as well as increasing elastin biosynthesis.

Astragaloside IV improves vascular endothelial dysfunction by inhibiting the TLR4/NF-κB signaling pathway

AIMS

Astragaloside IV (As-IV) is the major active ingredient of Astragalus membranaceus and has diverse pharmacological activities, including anti-inflammatory and antioxidant effects. However, the beneficial effect of As-IV on protecting vascular endothelial dysfunction is not completely understood. The aim of this study was to investigate the protective effect and mechanism of As-IV on vascular endothelial dysfunction.

MATERIALS AND METHODS

A diabetes model was established by intraperitoneal injection of streptozotocin (STZ). Endothelial function in isolated aortic rings was examined; serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were tested by ELISA. The expression of nuclear Factor-κB p65 (NF-κB p65) in aortic tissue was detected by immunohistochemistry. Plasma nitric oxide (NO) was measured by the nitrate reductase method. The expressions of endothelial nitric oxide synthase (eNOS), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and toll-like receptor 4 (TLR4) in aortic tissue were determined by western blot.

KEY FINDINGS

The results showed that As-IV significantly improved aortic endothelial function; increased eNOS expression and NO production; and decreased the content of IL-6 and TNF-α and the expressions of VCAM-1, ICAM-1, TLR4, and nuclear NF-κB p65 in vitro and in vivo. In addition, the above mentioned effects of As-IV on human umbilical vein endothelial cells (HUVECs) were similar to TAK-242 (TLR4 inhibitor) and Bay 11-7082 (NF-κB p65 inhibitor). Furthermore, L-NAME (NO synthesis inhibitor) partially abolished the effect of As-IV.

SIGNIFICANCE

As-IV could improve vascular endothelial dysfunction induced by hyperglycemia, and the protective effect of As-IV may be via the TLR4/NF-κB signaling pathway.

Systematic screening and characterization of Qi-Li-Qiang-Xin capsule-related xenobiotics in rats by ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry

Qi-Li-Qiang-Xin capsule (QLQX), a well-known traditional Chinese medicine prescription (TCMP), is consisted of eleven commonly used herbal medicines, has been widely used for the treatment of chronic heart failure (CHF). However, the absorbed components and related metabolites after oral administration of QLQX are still remaining unknown. In the present work, a reliable and effective method using ultra performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS) was established to identify QLQX-related xenobiotics in rats. Based on a representative structure based homologous xenobiotics identification (RSBHXI) strategy, a total of eleven compounds (salvianolic acid B, formononetin, benzoylmesaconine, alisol A, sinapine thiocyanate, naringin, tanshinone IIA, ginsenoside Rg1, ginsenoside Rb1, astragaloside IV and periplocin), bearing different chemical core structures, were selected and investigated for their metabolism in vivo. And then, comprehensive metabolic profiles of the holistic multi-ingredients in QLQX were achieved. As a result, a total of 121 QLQX-related xenobiotics (47 prototypes and 74 metabolites) were identified or tentatively characterized, among them eight prototypes (mesaconine, hypaconine, songorine, fuziline, neoline, talatizamine formononetin, neocryptotanshinone) and two metabolites (calycosin-gluA, formononetin-guA) were relatively the main existing xenobiotics exposed in blood. All absorbed prototype constituents were mainly from six composed herbal medicines (Aconiti lateralis radix, Astragali radix, Ginseng radix, Alismatis rhizoma, Salvia miltiorrhiza radix, Periploca cortex). The main metabolic reactions were methylation, hydrogenation, hydroxylation, oxidization, sulfation and glucuronidation. This is the first study on in vivo metabolism of QLQX. These results enabled us to focus on several high exposure ingredients in the discovery of effective substances of QLQX, however further pharmacokinetic study on these QLQX-related xenobiotics are needed to be carried out.

Pharmacokinetics of Chinese medicines: strategies and perspectives

The modernization and internationalization of Chinese medicines (CMs) are hampered by increasing concerns on the safety and the efficacy. Pharmacokinetic (PK) study is indispensable to establish concentration-activity/toxicity relationship and facilitate target identification and new drug discovery from CMs. To cope with tremendous challenges rooted from chemical complexity of CMs, the classic PK strategies have evolved rapidly from PK study focusing on marker/main drug components to PK-PD correlation study adopting metabolomics approaches to characterize associations between disposition of global drug-related components and host metabolic network shifts. However, the majority of PK studies of CMs have adopted the approaches tailored for western medicines and focused on the systemic exposures of drug-related components, most of which were found to be too low to account for the holistic benefits of CMs. With an area under concentration-time curve- or activity-weighted approach, integral PK attempts to understand the PK-PD relevance with the integrated PK profile of multiple co-existing structural analogs (prototyes/metabolites). Cellular PK-PD complements traditional PK-PD when drug targets localize inside the cells, instead of at the surface of cell membrane or extracellular space. Considering the validated clinical benefits of CMs, reverse pharmacology-based reverse PK strategy was proposed to facilitate target identification and new drug discovery. Recently, gut microbiota have demonstrated multifaceted roles in drug efficacy/toxicity. In traditional oral intake, the presystemic interactions of CMs with gut microbiota seem inevitable, which can contribute to the holistic benefits of CMs through biotransforming CMs components, acting as the peripheral target, and regulating host drug disposition. Hence, we propose a global PK-PD approach which includes the presystemic interaction of CMs with gut microbiota and combines omics with physiologically based pharmacokinetic modeling to offer a comprehensive understanding of the PK-PD relationship of CMs. Moreover, validated clinical benefits of CMs and poor translational potential of animal PK data urge more research efforts in human PK study.

Ginseng polysaccharides enhanced ginsenoside Rb1 and microbial metabolites exposure through enhancing intestinal absorption and affecting gut microbial metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Polysaccharides and small molecules commonly co-exist in decoctions of traditional Chinese medicines (TCMs). Our previous study outlined that ginseng polysaccharides (GP) could interact with co-existing ginsenosides to produce synergistic effect in an over-fatigue and acute cold stress model via gut microbiota involved mechanisms.

AIM OF THE STUDY

This study aimed to verify the interactions by examining the impact of GP on oral pharmacokinetics of ginsenoside Rb1 (Rb1), the dominant protopanoxadiol (PPD)-type ginsenoside in Ginseng, on a dextran sulphate sodium (DSS) induced experimental colitis model which was characterized by gut dysbiosis, and to delineate the underlying mechanisms in vitro.

MATERIALS AND METHODS

Rats received drinking water (normal group), 5% DSS (UC group), or 5% DSS plus daily oral administration of GP (GP group) for 7 days and fecal samples were collected on day -3, 0 and 6. On day 7 all animals received an oral dosage of Rb1 and blood samples were withdrawn for pharmacokinetic study. The in vitro metabolism study of Rb1 in gut microbiota from normal and UC rats and the transport study of Rb1 across Caco-2 cell monolayer were carried out in presence/absence of GP. Rb1 and its bacterial metabolites ginsenoside Rd (Rd), ginsenoside F2 (F2), Compound K (CK) and PPD were determined using LC-MS/MS. Total and target bacteria in fecal samples were determined by using 16S rRNA-based RT-PCR. β-Glucosidase activity was determined by measuring 4-nitrophenol formed from 4-nitrophenyl-β-D-glucopyranoside hydrolysis.

RESULTS

DSS induction did not alter AUC_0-t and C_max of Rb1, which, however, were doubled together with elevated AUC_0-t of the metabolites, in particular Rd and CK, in GP group. GP influenced the microbial composition and showed a prebiotic-like effect. Accordingly, GP treatment could partially restore the β-glucosidase activity which was reduced by DSS induction. The presence of GP resulted in quicker microbial metabolism of Rb1 and higher Rd formation in first 8 h of incubation, while the impact on F2 and CK formation/conversion became obvious after 8 h. More interestingly, GP slightly stimulated Caco-2 cell growth and facilitated Rb1 transport across the Caco-2 monolayer in both directions, increasing the P_app of Rb1 from 10^-7 cm/s to 10^-6 cm/s.

CONCLUSIONS

GP alleviated DSS-induced colitis-like symptoms and enhanced the systemic exposure of Rb1 through enhancing microbial deglycosylation and intestinal epithelial absorption of Rb1. These findings further demonstrated the important role of gut microbiota in the multifaceted action of polysaccharides in the holistic actions of traditional decoction of TCMs.

Astragaloside VI and cycloastragenol-6-O-beta-D-glucoside promote wound healing in vitro and in vivo

BACKGROUND

Astragalus genus includes most of the common, historical herbal medicines that have various applications in Asian countries. However, clinical data and mechanistic insights into their actions are still lacking.

PURPOSE

In this study, we aimed to examine the effects of astragalosides on wound healing in vitro and in vivo, as well as the underlying mechanisms of these actions.

METHODS

The wound healing activity of astragalosides was investigated in human HaCaT keratinocytes, human dermal fibroblast (HDF) cells, and murine models of wound healing.

RESULTS

All eight astragalosides studied enhanced epidermal growth factor receptor (EGFR) activity in HaCaT cells. Among them, astragaloside VI (AS-VI) showed the strongest EGFR activation. Consistently, AS-VI and cycloastragenol-6-O-beta-D-glucoside (CMG), which is the major metabolite of astragalosides, enhanced extracellular signal-regulated kinase (ERK) activity in a concentration-dependent manner. In agreement, both compounds induced EGFR-dependent cell proliferation and migration in HaCaT and HDF cells. In addition, we showed that AS-VI and CMG accelerated the healing of both sterile and infected wounds in vivo. These effects were associated with increased angiogenesis in the scar tissue.

CONCLUSION

AS-VI and CMG increased the proliferation and migration of skin cells via activation of the EGFR/ERK signalling pathway, resulting in the improvement of wound healing in vitro and in vivo. These findings indicate the therapeutic potential of AS-VI and CMG to accelerate wound healing; additionally, they suggest the mechanistic basis of this activity.

Poly-pharmacokinetic Study of a Multicomponent Herbal Medicine in Healthy Chinese Volunteers

The advent of mass spectrometry-based analytical technologies coupled with multivariate statistical methods offer tremendous new opportunities for understanding the pharmacokinetics (PKs) of multicomponent herbal medicines (HMs). We recently proposed a poly-PK strategy to characterize the concentration-time profile and the metabolic response profile of multicomponent HMs using an integrated phytochemical and metabolomics approach. Here, we provided the first example of the poly-PK strategy, in which we simultaneously characterized the PK as well as the metabolic response profiles of a Chinese HM, Huangqi decoction (HQD, consisting of Radix Astragali and Radix Glycyrrhizae), in healthy Chinese volunteers. Using the poly-PK approach, we identified 56 HQD-derived compounds and 292 biotransformed HQD metabolites in human plasma. Additionally, we acquired the concentration-time profiles of these plasma HQD metabolites and correlated them with a plasma metabolomics profile consisting of 166 human endogenous metabolites that were significantly altered in response to HQD intervention.

Using UPLC-MS/MS for Characterization of Active Components in Extracts of Yupingfeng and Application to a Comparative Pharmacokinetic Study in Rat Plasma after Oral Administration

Yupingfeng (YPF), a famous traditional Chinese medicine, which contains a large array of compounds, has been effectually used in health protection. A two-dimensional liquid chromatography (²D-LC) combined with quadrupole time-of-flight mass spectrometry (QTOF-MS) method was firstly established to separate and identify chemical components in YPF. A total of 33 compounds were identified, including 15 constituents (flavonoids and saponins) in Astragali radix; seven constituents (sesquiterpenoids and polysaccharide) in Atractylodis rhizoma; and 11 constituents (chromone and coumarins) in Saposhnikoviae radix. The corresponding fragmentation pathway of typical substances was investigated. Then, seven active constituents (astragaloside, calycosin, formononetin, cimicifugoside, 4-O-beta-d-glucosyl-5-O-methylvisamminol, sec-O-glucosylhamaudol, and atractylenolide II) derived from three medicinal plants were chosen to further investigate the pharmacokinetic behavior of YPF formula using ultrahigh-performance liquid chromatography with triple quadrupole mass spectrometry system. The method was sensitive, accurate and reliable. We also used the area under the plasma concentration-time curve from zero to infinity (AUC_0-∞) as weighting factor to make an integrated pharmacokinetic curve. Results show that the constituents of Saposhnikoviae radix have the best absorption and pharmacokinetic behavior and may play important role in leading to the changes of overall therapeutic effects of YPF. Further study is needed to confirm the association between them.

Cycloastragenol improves hepatic steatosis by activating farnesoid X receptor signalling

Non-alcoholic fatty liver disease (NAFLD) has become a global health problem. However, there is no approved therapy for NAFLD. Farnesoid X receptor (FXR) is a potential drug target for treatment of NAFLD. In an attempt to screen FXR agonists, we found that cycloastragenol (CAG), a natural occurring compound in Astragali Radix, stimulated FXR transcription activity. In animal studies, we demonstrated that CAG treatment resulted in obvious reduction of high-fat diet induced lipid accumulation in liver accompanied by lowered blood glucose, serum triglyceride levels and hepatic bile acid pool size. The stimulation of FXR signalling by CAG treatment in DIO mice was confirmed via gene expression and western blot analysis. Molecular docking data further supported the interaction of CAG and FXR. In addition, CAG alleviated hepatic steatosis in methionine and choline deficient L-amino acid diet (MCD) induced non-alcoholic steatohepatitis (NASH) mice. Our data suggest that CAG ameliorates NAFLD via the enhancement of FXR signalling.

Pharmacokinetic alterations of rhubarb anthraquinones in experimental colitis induced by dextran sulfate sodium in the rat

ETHNOPHARMACOLOGICAL RELEVANCE

Rhubarb (Rhei Rhizoma et Radix) is used for the treatment of digestive diseases in traditional medicinal practice in China. Recent studies also support its beneficial activities in alleviating ulcerative colitis (UC).

AIM OF THE STUDY

This study aimed to characterize the oral pharmacokinetics of rhubarb anthraquinones, the main bioactive components of this herb, in the experimental chronic colitis rat model induced by dextran sulfate sodium (DSS) and to identify the factors causing the pharmacokinetic alterations.

MATERIALS AND METHODS

Rats received drinking water (normal group) or 5% DSS for the first 7 days and 3% DSS for additional 14 days (UC group). On day 21 both groups received an oral dose of the rhubarb extract (equivalent to 5.0g crude drug/kg body weight). Plasma anthraquinone aglycones levels were determined directly by an LC-MS/MS method and the total of each anthraquinone (aglycone+conjugates) was quantified after β-glucuronidases hydrolysis.

RESULTS

Rhubarb anthraquinones predominantly existed as conjugates in plasma samples from both groups and only free aloe-emodin, rhein and emodin were detected. Compared to the normal rats, both C_max and AUC of the three free anthraquinones were increased, while the systemic exposure (AUC) of the total (aglycone+conjugates) of most anthraquinones decreased by UC accompanied by the disappearance of multiple-peak phenomenon in the plasma concentration-time profiles. Gut bacteria from UC rats exhibited a decreased activity in hydrolyzing anthraquinone glycosides to form respective aglycone and there were significant decreases in microbial β-glucosidases and β-glucuronidases activities. Moreover, the intestinal microsomes from UC rats catalyzed glucuronidation of free anthraquinones with higher activities, while the activities of hepatic microsomes were comparable to normal rats.

CONCLUSIONS

The decreases of β-glucuronidases activity in DSS-induced chronic rat colitis should mainly account for the decreases in systemic exposure and abrogation of enterohepatic recirculation of most rhubarb anthraquinones after oral intake.

Understanding the Molecular Mechanisms of the Interplay Between Herbal Medicines and Gut Microbiota

Herbal medicines (HMs) are much appreciated for their significant contribution to human survival and reproduction by remedial and prophylactic management of diseases. Defining the scientific basis of HMs will substantiate their value and promote their modernization. Ever-increasing evidence suggests that gut microbiota plays a crucial role in HM therapy by complicated interplay with HM components. This interplay includes such activities as: gut microbiota biotransforming HM chemicals into metabolites that harbor different bioavailability and bioactivity/toxicity from their precursors; HM chemicals improving the composition of gut microbiota, consequently ameliorating its dysfunction as well as associated pathological conditions; and gut microbiota mediating the interactions (synergistic and antagonistic) between the multiple chemicals in HMs. More advanced experimental designs are recommended for future study, such as overall chemical characterization of gut microbiota-metabolized HMs, direct microbial analysis of HM-targeted gut microbiota, and precise gut microbiota research model development. The outcomes of such research can further elucidate the interactions between HMs and gut microbiota, thereby opening a new window for defining the scientific basis of HMs and for guiding HM-based drug discovery.

Mori Cortex regulates P-glycoprotein in Caco-2 cells and colons from rats with experimental colitis via direct and gut microbiota-mediated mechanisms

Mori cortex enhances intestinal epithelial barrier function by up-regulating P-glycoproteinviadirect and gut microbiota-mediated mechanisms.

Evaluation and Comparison of the Inhibition Effect of Astragaloside IV and Aglycone Cycloastragenol on Various UDP-Glucuronosyltransferase (UGT) Isoforms

As one of the main active ingredients from Radix Astragali (RA), orally dosed astragaloside IV (AST) is easily transformed to sapogenin-cycloastragenol (CAG) by deglycosylation in the gastrointestinal tract. Because the potential adverse effects of AST and CAG remain unclear, the present study in this article was carried out to investigate the inhibition effects of AST and CAG on UDP-glucuronosyltransferases (UGTs) to explore potential clinical toxicity. An in vitro UGTs incubation mixture was employed to study the inhibition of AST and CAG towards UGT isoforms. Concentrations of 100 μM for each compound were used to initially screen the inhibitory efficiency. Deglycosylation of AST to CAG could strongly increase the inhibitory effects towards almost all of the tested UGT isoforms, with an IC₅₀ of 0.84 μM and 11.28 μM for UGT1A8 and UGT2B7, respectively. Ulteriorly, the inhibition type and kinetics of CAG towards UGT1A8 and UGT2B7 were evaluated depending on the initial screening results. Data fitting using Dixon and Lineweaver-Burk plots demonstrated that CAG competitively inhibited UGT1A8 and noncompetitively inhibited UGT2B7. From the second plot drawn with the slopes from the Lineweaver-Burk plot versus the concentrations of CAG, the inhibition constant (Ki) was calculated to be 0.034 μM and 20.98 μM for the inhibition of UGT1A8 and UGT2B7, respectively. Based on the [I]/Ki standard ([I]/Ki < 0.1, low possibility; 1 > [I]/Ki > 0.1, medium possibility; [I]/Ki > 1, high possibility), it was successfully predicted here that an in vivo herb-drug interaction between AST/CAG and drugs mainly undergoing UGT1A8- or UGT2B7-catalyzed metabolism might occur when the plasma concentration of CAG is above 0.034 μM and 20.98 μM, respectively.

Research review on the pharmacological effects of astragaloside IV

Astragalus membranaceus Bunge has been used to treat numerous diseases for thousands of years. As the main active substance of Astragalus membranaceus Bunge, astragaloside IV (AS-IV) also demonstrates the potent protective effect on focal cerebral ischemia/reperfusion, cardiovascular disease, pulmonary disease, liver fibrosis, and diabetic nephropathy. Based on studies published during the past several decades, the current state of AS-IV research and the pharmacological effects are detailed, elucidated, and summarized. This review systematically summarizes the pharmacological effects, metabolism mechanism, and the toxicity of AS-IV. AS-IV has multiple pharmacologic effects, including anti-inflammatory, antifibrotic, antioxidative stress, anti-asthma, antidiabetes, immunoregulation, and cardioprotective effect via numerous signaling pathways. According to the existing studies and clinical practices, AS-IV possesses potential for broad application in many diseases.

Gastroprotective Effects of Astragaloside IV against Acute Gastric Lesion in Rats

Background

Protection of the gastric mucosa from acute lesions induced by various irritants is a pertinent issue in the field of critical care medicine. In this study, we investigated the gastroprotective effects of astragaloside IV on acute gastric lesions in rats under stressful conditions.

Methods

Rats were randomized into six groups. Group 1 and 2 received 10% Tween 80 (vehicle). Group 3 received 20 mg/kg of omeprazole, a proton pump inhibitor. Groups 4, 5 and 6 received astragaloside IV at concentration of 1, 10, and 50 mg/kg, respectively. As a means to induce gastric lesions, Groups 2–6 were subjected to water immersion and restraint stress for 12 hours after treatment.

Results

Our present studies show that compared to rats in group 2, treatment with 1 to 50 mg/kg astragaloside IV significantly decreased the size of gastric lesions, MDA, TNFα and MCP1 levels, in addition to normalizing gastric pH, gastric mucus and SOD levels (P<0.05). Histomorphological examination confirmed that treatment with astragaloside IV elicited a dosage-dependent protective effect on the gastric mucosa. Furthermore, pretreatment with astragaloside IV resulted in significant elevations in HSP70 and reduction in Bax, along with over-expression of PLCγ response level, which was further confirmed via immunohistochemical analysis.

Conclusions

The acute gastric lesions induced are attenuated by pretreatment with astragaloside IV which is possibly due to the enhancing of the expression of HSP70 with concomitant antioxidant, anti-inflammatory and anti-apoptotic capacity.

Disposition of Astragaloside IV via Enterohepatic Circulation Is Affected by the Activity of the Intestinal Microbiome

Astragaloside IV (ASIV) is a typical bioactive constituent of Radix Astragali. The study aimed to investigate the enterohepatic circulation of ASIV and evaluate the impact of activity of intestinal microbiota on the deposition of ASIV. The amounts of ASIV and its metabolites were quantified by an LC-MS/MS method. ASIV was metabolized by intestinal bacteria to form brachyoside B (Bra B), cyclogaleginoside B (Cyc B), cycloastragenol (CA), iso-cycloastragenol (iso-CA), and dehydrogenated metabolite of CA (CA-2H). CA and iso-CA circulated in blood besides ASIV when rats received ASIV intragastrically or intravenously. After rats were intragastrically administered 10 mg/kg ASIV, the AUC0-t values of ASIV, CA, and iso-CA were 109 ± 55, 26.8 ± 17.9, and 77.9 ± 35.1 nM·h, respectively. The plasma distribution of ASIV was significantly affected by bile duct drainage when ASIV was administered through the duodenum. ASIV, Bra B, and Cyc B were secreted from bile after duodenal administration of ASIV. Antibiotics markedly inhibited the metabolism of ASIV in intestinal microbiota. After rats were pretreated with antibiotics, the AUC0-t of iso-CA was 4.8 times less than that in control rats and the concentration of CA became undetectable. Variations in intestinal microbiota may change the disposition of ASIV and subsequently influence its potential health benefits.