Identification of Echinacoside Metabolites Produced by Human Intestinal Bacteria Using Ultraperformance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry

Regulation of mitophagy and mitochondrial function: Natural compounds as potential therapeutic strategies for Parkinson's disease

Mitochondrial damage is associated with the development of Parkinson's disease (PD), indicating that mitochondrial-targeted treatments could hold promise as disease-modifying approaches for PD. Notably, natural compounds have demonstrated the ability to modulate mitochondrial-related processes. In this review article, we discussed the possible neuroprotective mechanisms of natural compounds against PD in modulating mitophagy and mitochondrial function. A comprehensive literature search on natural compounds related to the treatment of PD by regulating mitophagy and mitochondrial function was conducted from PubMed, Web of Science and Chinese National Knowledge Infrastructure databases from their inception until April 2023. We summarize recent advancements in mitophagy's molecular mechanisms, including upstream and downstream processes, and its relationship with PD-related genes or proteins. Importantly, we highlight how natural compounds can therapeutically regulate various mitochondrial processes through multiple targets and pathways to alleviate oxidative stress, neuroinflammation, Lewy's body aggregation and apoptosis, which are key contributors to PD pathogenesis. Unlike the single-target strategy of modern medicine, natural compounds provide neuroprotection against PD by modulating various mitochondrial-related processes, including ameliorating mitophagy by targeting the PINK1/parkin pathway, the NIX/BNIP3 pathway, and autophagosome formation (i.e., LC3 and p62). Given the prevalence of mitochondrial damage in various neurodegenerative diseases, exploring the exact mechanism of natural compounds on mitophagy and mitochondrial dysfunction could shed light on the development of highly effective disease-modifying or adjuvant therapies targeting PD and other neurodegenerative disorders.

Echinacoside inhibits colorectal cancer metastasis via modulating the gut microbiota and suppressing the PI3K/AKT signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Echinacoside (ECH) is the dominant phenylethanoid glycoside-structured compound identified from our developed herbal formula Huangci granule, which has been previously reported to inhibit the invasion and metastasis of CRC and prolong patients' disease-free survival duration. Though ECH has inhibitory activity against aggressive colorectal cancer (CRC) cells, its anti-metastasis effect in vivo and the action mechanism is undetermined. Given that ECH has an extremely low bioavailability and gut microbiota drives the CRC progression, we hypothesized that ECH could inhibit metastatic CRC by targeting the gut microbiome.

AIM OF THE STUDY

The purpose of this study was to investigate the impact of ECH on colorectal cancer liver metastasis in vivo and its potential mechanisms.

MATERIALS AND METHODS

An intrasplenic injection-induced liver metastatic model was established to examine the efficiency of ECH on tumor metastasis in vivo. Fecal microbiota from the model group and the ECH group were separately transplanted into pseudo-sterile CRLM mice in order to verify the role of gut flora in the ECH anti-metastatic effect. The 16S rRNA gene sequence was applied to analyze the structure and composition of the gut microbiota after ECH intervention, and the effect of ECH on short-chain fatty acid (SCFAs)-producing bacteria growth was proven by anaerobic culturing in vitro. GC-MS was applied to quantitatively analyze the serum SCFAs levels in mice. RNA-seq was performed to detect the gene changes involving tumor-promoting signaling pathway.

RESULTS

ECH inhibited CRC metastasis in a dose-dependent manner in the metastatic colorectal cancer (mCRC) mouse model. Manipulation of gut bacteria in the mCRC mouse model further proved that SCFA-generating gut bacteria played an indispensable role in mediating the antimetastatic action of ECH. Under an anaerobic condition, ECH benefited SCFA-producing microbiota without affecting the total bacterial load, presenting a dose-dependent promotion on the growth of a butyrate producer, Faecalibacterium prausnitzii (F.p). Furthermore, ECH-reshaped or F.p-colonized microbiota with a high butyrate-producing capability inhibited liver metastasis by suppressing PI3K/AKT signaling and reversing the epithelial-mesenchymal transition (EMT) process, whereas this anti-metastatic ability was abrogated by the butyrate synthase inhibitor heptanoyl-CoA.

CONCLUSION

This study demonstrated that ECH exhibits oral anti-metastatic efficacy by facilitating butyrate-producing gut bacteria, which downregulates PI3K/AKT signaling and EMT. It hints at a novel role for ECH in CRC therapy.

Echinacoside: A promising active natural products and pharmacological agents

Echinacoside, a natural phenylethanoid glycoside, was discovered and isolated from the garden plant Echinacea angustifolia DC., belonging to the Compositae family, approximately sixty years ago. Extensive investigations have revealed that it possesses a wide array of pharmacologically beneficial activities for human health, particularly notable for its neuroprotective and anticancer activity. Several crucial concerns surfaced, encompassing the recognition of active metabolites that exhibited inadequate bioavailability in their prototype form, the establishment of precise molecular signal pathways or targets associated with the aforementioned effects of echinacoside, and the scarcity of dependable clinical trials. Hence, the question remains unanswered as to whether scientific research can effectively utilize this natural compound. To support future studies on this natural product, it is imperative to provide a systematic overview and insights into potential future prospects. The current review provides a comprehensive analysis of the existing knowledge on echinacoside, encompassing its wide distribution, structural diversity and metabolism, diverse therapeutic applications, and improvement of echinacoside bioavailability for its potential utilization.

Time-Series-Dependent Global Data Filtering Strategy for Mining and Profiling of Xenobiotic Metabolites in a Dynamic Complex Matrix: Application to Biotransformation of Flavonoids in the Extract of Ginkgo biloba by Gut Microbiota

Efficient characterization of xenobiotic metabolites and their dynamics in a changing complex matrix remains difficult. Herein, we proposed a time-series-dependent global data filtering strategy for the rapid and comprehensive characterization of xenobiotic metabolites and their dynamic variation based on metabolome data. A set of data preprocessing methods was used to screen potential xenobiotic metabolites, considering the differences between the treated and control groups and the fluctuations over time. To further identify metabolites of the target, an in-house accurate mass database was constructed by potential metabolic pathways and applied. Taking the extract of Ginkgo biloba (EGB) co-incubated with gut microbiota as an example, 107 compounds were identified as flavonoid-derived metabolites (including 67 original from EGB and 40 new) from 7468 ions. Their temporal metabolic profiles and regularities were also investigated. This study provided a systematic and feasible method to elucidate and profile xenobiotic metabolism.

Combination of UPLC-Q-TOF/MS and Network Pharmacology to Reveal the Mechanism of Qizhen Decoction in the Treatment of Colon Cancer

Traditional Chinese medicine (TCM) has been utilized for the treatment of colon cancer. Qizhen decoction (QZD), a potential compound prescription of TCM, possesses multiple biological activities. It has been proven clinically effective in the treatment of colon cancer. However, the molecular mechanism of anticolon cancer activity is still not clear. This study aimed to identify the chemical composition of QZD. Furthermore, a collaborative analysis strategy of network pharmacology and cell biology was used to further explore the critical signaling pathway of QZD anticancer activity. First, ultraperformance liquid chromatography-quadrupole time-of-flight/mass spectrometry (UPLC-Q-TOF/MS) was performed to identify the chemical composition of QZD. Then, the chemical composition database of QZD was constructed based on a systematic literature search and review of chemical constituents. Moreover, the common and indirect targets of chemical components of QZD and colon cancer were searched by multiple databases. A protein-protein interaction (PPI) network was constructed using the String database (https://www.string-db.org/). All of the targets were analyzed by Gene Oncology (GO) bioanalysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and the visual network topology diagram of "Prescription-TCM-Chemical composition-Direct target-Indirect target-Pathway" was constructed by Cytoscape software (v3.7.1). The top molecular pathway ranked by statistical significance was further verified by molecular biology methods. The results of UPLC-Q-TOF/MS showed that QZD had 111 kinds of chemical components, of which 103 were unique components and 8 were common components. Ten pivotal targets of QZD in the treatment of colon cancer were screened by the PPI network. Targets of QZD involve many biological processes, such as the signaling pathway, immune system, gene expression, and so on. QZD may interfere with biological pathways such as cell replication, oxygen-containing compounds, or organic matter by protein binding, regulation of signal receptors or enzyme binding, and affect cytoplasm and membrane-bound organelles. The main antitumor core pathways were the apoptosis metabolic pathway, the PI3K-Akt signal pathway, and so on. Expression of the PI3K-Akt signal pathway was significantly downregulated after the intervention of QZD, which was closely related to the inhibition of proliferation and migration of colon cancer cells by cell biology methods. The present work may facilitate a better understanding of the effective components, therapeutic targets, biological processes, and signaling pathways of QZD in the treatment of colon cancer and provide useful information about the utilization of QZD.

Stable isotope labeling derivatization combined with multiple-mass spectrometry technologies to monitor metabolites of tenuifoliside A incubated with intestinal bacteria incubation model

Aromatic carboxylic acids (ACAs), play important roles in preventive and therapeutic effects for some diseases. However, complex matrix effect and poor detection sensitivity make it difficult and even rare to detect ACAs in complex bio-samples. Herein, a stable isotope labeling derivatization (SILD) method based on one-pot synthesis of carboxylic amides by aniline (AN) and aniline-d₅ (AN-d₅) was firstly designed for quantitatively monitoring ACAs under mild conditions. The detection sensitivity was improved up to 500 folds. Importantly, when taking the trace tenuifoliside A (TA) containing p-hydroxyl-benzoyl- (HB) and 3, 4, 5-trimethoxylcinnamoyl- (TC) unit as a special example via intestinal bacteria incubation, the metabolites ACAs and whole metabolic profiles of TA were firstly accurately and systematically monitored by applying the SILD method combined with multiple-mass spectrometry (MMS) technologies. It provides a convenient, universal, high-sensitivity and high-recovery methodological tool for the systematically metabolic study of trace drugs in vitro and in vivo.

Cistanches Herba, from an endangered species to a big brand of Chinese medicine

Cistanches Herba (CH, Chinese name: Roucongrong), is a very precious, tonic Chinese medicine. Cistanche deserticola and Cistanche tubulosa are the two commonly used species and authenticated in Chinese Pharmacopoeia. Due to the parasitic nature of Cistanche plants, the wild source was once endangered and listed in the Appendix II of Convention on International Trade in Endangered Species of Wild Fauna and Flora. However, after continuously struggling in the past decades, CH has grown up to a big brand of Chinese medicine featured with the cultivation area as 1.26 million mu, the annual output as 6000 tons, and the related industrial output value as more than 20 billion China Yuan, attributing to large-scale cultivation and in-depth phytochemical and pharmacological investigations. Noteworthily, great achievements have reached concerning the research and development of relevant products, such as modern drugs, traditional Chinese medicine prescriptions, and dietary supplements. The current review summarizes the research progresses concerning the distribution and cultivation, phytochemistry, pharmacology, metabolism and product development of CH in the past decades, and the emerging challenges and developing prospects are discussed as well.

Therapeutic potential of phenylethanoid glycosides: A systematic review

Phenylethanoid glycosides (PhGs) are generally water-soluble phenolic compounds that occur in many medicinal plants. Until June 2020, more than 572 PhGs have been isolated and identified. PhGs possess antibacterial, anticancer, antidiabetic, anti-inflammatory, antiobesity, antioxidant, antiviral, and neuroprotective properties. Despite these promising benefits, PhGs have failed to fulfill their therapeutic applications due to their poor bioavailability. The attempts to understand their metabolic pathways to improve their bioavailability are investigated. In this review article, we will first summarize the number of PhGs compounds which is not accurate in the literature. The latest information on the biological activities, structure-activity relationships, mechanisms, and especially the clinical applications of PhGs will be reviewed. The bioavailability of PhGs will be summarized and factors leading to the low bioavailability will be analyzed. Recent advances in methods such as bioenhancers and nanotechnology to improve the bioavailability of PhGs are also summarized. The existing scientific gaps of PhGs in knowledge are also discussed, highlighting research directions in the future.

Cistanche polysaccharides enhance echinacoside absorption in vivo and affect the gut microbiota

The polysaccharides and phenylethanoid glycosides from Cistanche deserticola have been demonstrated with various health benefits, however the interactive effect between these two kinds of compounds in vivo are not in detail known. The objective of this study was to investigate the synergistic actions of cistanche polysaccharides with phenylethanoid glycoside and the effects of polysaccharides on gut microbiota. Sprague-Dawley rats were fed with different kinds of cistanche polysaccharides for 20 days, on the last day, all rats were administered the echinacoside at 100 mg/kg. The results were compared mainly on the difference of pharmacokinetic parameters, gut microbiota composition, and short chain fatty acids contents. The results indicated that all the cistanche polysaccharides, including crude polysaccharide, high molecular weight polysaccharide and low molecular weight polysaccharide, could regulate the gut microbiota diversity, increase beneficial bacteria and particularly enhance the growth of Prevotella spp. as well as improve the production of short chain fatty acids and the absorption of echinacoside. By exploring the synergistic actions of polysaccharides with small molecules, these findings suggest that cistanche polysaccharides, particularly low molecular weight polysaccharides, could be used as a gut microbiota manipulator for health promotion.

An Integrated Approach to Characterize Intestinal Metabolites of Four Phenylethanoid Glycosides and Intestinal Microbe-Mediated Antioxidant Activity Evaluation In Vitro Using UHPLC-Q-Exactive High-Resolution Mass Spectrometry and a 1,1-Diphenyl-2-picrylhydrazyl-Based Assay

Intestinal bacteria have a significant role in metabolism and the pharmacologic actions of traditional Chinese medicine active ingredients. Phenylethanoid glycosides (PhGs), as typical phenolic natural products, possess wide bioactivities, but low oral bioavailability. The aim of this work was to elucidate the metabolic mechanism underlying PhGs in the intestinal tract and screen for more active metabolites. In this study, a rapid and reliable method using an effective post-acquisition approach based on advanced ultra-high-performance liquid chromatography (UHPLC) coupled with hybrid Quadrupole-Orbitrap high resolution mass spectrometry (Q-Exactive-HRMS) provided full MS and HCD MS² data. Thermo Scientific™ Compound Discoverer™ software with a Fragment Ion Search (FISh) function in one single workflow was developed to investigate the intestinal microbial metabolism of four typical PhGs. Furthermore, antioxidant activity evaluation of PhGs and their related metabolites was simultaneously carried out in combination with a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to understand how intestinal microbiota transformations modulate biological activity and explore structure–activity relationships (SARs). As a result, 26 metabolites of poliumoside, 42 metabolites of echinacoside, 42 metabolites of tubuloside, and 46 metabolites of 2′-acetylacteoside were identified. Degradation, reduction, hydroxylation, acetylation, hydration, methylation, and sulfate conjugation were the major metabolic pathways of PhGs. Furthermore, the degraded metabolites with better bioavailability had potent antioxidant activity that could be attributed to the phenolic hydroxyl groups. These findings may enhance our understanding of the metabolism, pharmacologic actions, and real active forms of PhGs.

Inhibition of Amyloid Beta Aggregation and Deposition of Cistanche tubulosa Aqueous Extract

Cistanche tubulosa aqueous extract (CTE) is already used as a botanical prescription drug for treating dementia in China. Our previous studies reported that phenylethanoid glycosides of CTE have anti-Alzheimer's disease (AD) activity by inhibiting amyloid β peptide (Aβ) aggregation and deposition. However, recent studies considered that the phenylethanoid glycosides may be metabolized by intestinal bacteria, because all analysis results showed that the bioavailability of phenylethanoid glycosides is extremely low. In this study we demonstrate how iron chelation plays a crucial role in the Aβ aggregation and deposition inhibition mechanism of phenylethanoid glycosides of CTE. In addition, we further proved phenylethanoid glycosides (1⁻3) could reach brain. Active CTE component and action mechanism confirmation will be a great help for product quality control and bioavailability studies in the future. At the same time, we provide a new analysis method useful in determining phenylethanoid glycosides (1⁻3) in plants, foods, blood, and tissues for chemical fingerprint and pharmacokinetic research.

Effects of a homogeneous polysaccharide from Sijunzi decoction on human intestinal microbes and short chain fatty acids in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Sijunzi decoction (SJZD) is a classic recipe in traditional Chinese medicine (TCM) to strengthen the spleen and replenish Qi. It is well known for treating disorders of gastrointestinal function manifested in poor appetite, reduced food intake and loose stools. Polysaccharide is the most abundant constituent and the major effective component in SJZD.

AIM OF THE STUDY

The present study aimed to understand the immunomodulatory mechanism of S-3-1, a homogeneous polysaccharide purified from SJZD with immune-enhancement activity, by investigating its effects on human intestinal microbes and short chain fatty acids.

MATERIALS AND METHODS

S-3-1 was incubated with simulated gastric juice, intestinal juice, and human fecal microflora independently and sequentially. The concentrations of total polysaccharide and reducing sugar were measured to identify the stability of independently and sequentially incubated S-3-1 in three in vitro fermentation models. Gas chromatograph (GC) analysis was used to measure the short chain fatty acid (SCFA) contents in human fecal samples. The human gut microbiota composition was measured by 16S rRNA gene Illumina MiSeq sequencing (V3-V4 region).

RESULTS

S-3-1 was degraded in three in vitro fermentation models separately and sequentially. Both S-3-1 and incubated S-3-1 could regulate the abundances of Lactobacillus, Pediococcus, Streptococcus, Bacteroides, Enterococcus, Clostridium and Dorea in human intestinal microflora samples. Specifically, S-3-1 could only regulate the abundances of Paraprevotella and Oscillospira, while the influenced flora changed to Butyricimonas, Coprococcus, Dialister, Sutterella, Ruminococcus and Parabacteroides after sequential incubation of S-3-1. In contrast to S-3-1 showing no influence on the content of SCFA, incubated S-3-1 showed increased contents of acetic acid and total acid that were associated with its effects on the abundances of Enterococcus, Sutterella, Butyricimonas and Streptococcus.

CONCLUSION

S-3-1 plays an immunomodulatory role by regulating the abundances of 9 intestinal bacteria genera. Incubated S-3-1 can regulate more bacteria genera, a total of 13 kinds, and can adjust the SCFA content to affect immunomodulation. Incubation with gastric and intestinal juices enhanced S-3-1's capability of modulating the intestinal flora composition and decreased the bacteria's need for a carbon source. This study could provide new insights for studies on the pharmacological mechanisms of polysaccharides in vitro.

Cistanches Herba: An overview of its chemistry, pharmacology, and pharmacokinetics property

ETHNOPHARMACOLOGICAL RELEVANCE

Cistanches Herba is an Orobanchaceae parasitic plant. As a commonly used Traditional Chinese Medicine (TCM), its traditional functions include treating kidney deficiency, impotence, female infertility and senile constipation. Chemical analysis of Cistanches Herba revealed that phenylethanoid glycosides, iridoids, lignans, oligosaccharides, and polysaccharides were the main constituents. Pharmacological studies demonstrated that Cistanches Herba exhibited neuroprotective, immunomodulatory, hormonal balancing, anti-fatigue, anti-inflammatory, hepatoprotection, anti-oxidative, anti-bacterial, anti-viral, and anti-tumor effects, etc. The aim of this review is to provide updated, comprehensive and categorized information on the phytochemistry, pharmacological research and pharmacokinetics studies of the major constituents of Cistanches Herba.

MATERIALS AND METHODS

The literature search was conducted by systematic searching multiple electronic databases including SciFinder, ISI Web of Science, PubMed, Google Scholar and CNKI. Information was also collected from journals, local magazines, books, monographs.

RESULTS

To date, more than 100 compounds have been isolated from this genus, include phenylethanoid glycosides, carbohydrates, lignans, iridoids, etc. The crude extracts and isolated compounds have exhibited a wide range of in vitro and in vivo pharmacologic effects, such as neuroprotective, immunomodulatory, anti-inflammatory, hepatoprotection, anti-oxidative, anti-bacterial, and anti-tumor effects. The phenylethanoid glycosides, echinacoside and acteoside have attracted the most attention for their significantly neuropharmacology effects. Pharmacokinetic studies of echinacoside and acteoside also have also been summarized.

CONCLUSION

Phenylethanoid glycosides have demonstrated wide pharmacological actions and have great clinical value if challenges such as poor bioavailability, fast and extensive metabolism are addressed. Apart from phenylethanoid glycosides, other constituents of Cistanches Herba, their pharmacological activities and underlying mechanisms are also need to be studied further.

Amalgamation of polyphenols and probiotics induce health promotion

The residing microbiome with its vast repertoire of genes provide distinctive properties to the host by which they can degrade and utilise nutrients that otherwise pass the gastro-intestinal tract unchanged. The polyphenols in our diet have selective growth promoting effects which is of utmost importance as the state of good health has been linked to dominance of particular microbial genera. The polyphenols in native form might more skilfully exert anti-oxidative and anti-inflammatory properties but in a living system it is the microbial derivatives of polyphenol that play a key role in determining health outcome. This two way interaction has invoked great interest among researchers who have commenced several clinical surveys and numerous studies in in-vitro, simulated environment and living systems to find out in detail about the biomolecules involved in such interaction along with their subsequent physiological benefits. In this review, we have thoroughly discussed these studies to develop a fair idea on how the amalgamation of probiotics and polyphenol has an immense potential as an adjuvant therapeutic for disease prevention as well as treatment.

Comparison of the Chemical Profiles and Antioxidant Activities of Different Parts of Cultivated Cistanche deserticola Using Ultra Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry and a 1,1-Diphenyl-2-picrylhydrazyl-Based Assay

In this study, a sensitive ultra-performance liquid chromatography-photodiode array coupled to quadruple time-of-flight mass (UPLC-PDA-Q/TOF-MS) method and a 1,1-diphenyl-2-picrylhydrazyl (DPPH)-based assay were used to determine the chemical constituents and screen the antioxidant activity profiles of the methanol extracts of different parts of cultivated Cistanche deserticola (C. deserticola). First, qualitative and quantitative chemical composition analyses of the different parts of cultivated C. deserticola were conducted. Obvious differences were observed between the chemical profiles and content distribution of phenylethanoid glycosides (PhGs) from the different cultivated C. deserticola parts. The average contents of the six PhGs parts varied from 4.91 to 72.56 mg/g DW (milligrams of extract per gram of plant dry weight) in the six different parts of Cistanche deserticola, displaying a significant decreasing trend from the bottom to the top of cultivated C. deserticola and the highest content in the stems. From the bottom to the top of the plant, the echinacoside and cistanoside A content decreased and the 2′-acetylacteoside content increased. Second, an offline DPPH assay revealed that the total scavenging activities of all parts within the range of 20–500 µg/mL increased in a concentration-dependent manner and that good antioxidant activities were found in all plant parts, particularly in the stems, which could be related to their higher PhG content. Additionally, a DPPH-UPLC-PDA method was successfully applied to rapidly screen the antioxidant profiles and antioxidant components of the different cultivated C. deserticola parts. According to the antioxidant profiles before and after the DPPH reaction, there were wide variations in the antioxidant activities of different cultivated C. deserticola parts. Moreover, the antioxidant profiles revealed the presence of major free radical scavengers identified as PhGs using UPLC-Q/TOF-MS. Finally, the established DPPH-UPLC-PDA method was reagent saving, rapid and feasible for correlating the chemical profile of traditional chinese medicines (TCMs) with their bioactivities without isolation and purification and may be used for multicomponent analysis of active substances in other foods and herbs. Therefore, to better harness C. deserticola resources, using this method to evaluate cultivated C. deserticola, a promising herb material with obvious antioxidant activity, is crucial.

Human Gastrointestinal Metabolism of the Cistanches Herba Water Extract in Vitro: Elucidation of the Metabolic Profile Based on Comprehensive Metabolite Identification in Gastric Juice, Intestinal Juice, Human Intestinal Bacteria, and Intestinal Microsomes

Cistanches Herba is taken orally as a health food supplement and medicinal plant in Asian countries. It consists of the stems of Cistanche deserticola (CD) and Cistanche tubulosa (CT). The gastrointestinal metabolism of the multiple components contained in Cistanches Herba is crucial for the discovery of bioactive constituents. This study aims to elucidate the comprehensive metabolic profile of the Cistanches Herba water extract by simulating human gastrointestinal metabolism in vitro independently and sequentially using four models: gastric juice, intestinal juice, human intestinal bacteria, and human intestinal microsomes. A total of 35 and 18 metabolites were characterized from CD and CT water extracts, respectively. These metabolites were formed through reduction, methylation, dimethylation, deglycosylation, decaffeoyl, derhamnose, dehydrogenation, and glucuronidation. The difference in metabolites of the Cistanches Herba water extract and single compounds and the difference in metabolites of CD and CT water extracts were caused by the oligosaccharides and polysaccharides in Cistanches Herba.

A metabolic way to investigate related hurdles causing poor bioavailability in oral delivery of isoacteoside in rats employing ultrahigh-performance liquid chromatography/quadrupole time-of-flight tandem mass spectrometry

RATIONALE

Isoacteoside (ISAT), a phenylethanoid glycoside that acts as the principal bioactive component in traditional Chinese medicines, possesses broad pharmacological effects such as neuroprotective, antihypertensive and hepatoprotective activities. However, its pharmaceutical development has been severely limited due to the poor oral bioavailability. It is essential and significant to investigate related hurdles leading to the poor bioavailability of isoacteoside.

METHODS

Whole animal metabolism studies were conducted in rats, followed by metabolic mechanism including gastrointestinal stability, intestinal flora metabolism and intestinal enzyme metabolism employing the powerful method ultrahigh-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry (UPLC/QTOF-MS/MS).

RESULTS

A simple, rapid and sensitive method has been developed which comprehensively revealed the underlying cause of poor bioavailability of ISAT in a metabolic manner. The prototype of ISAT and its combined metabolites have not been detected in plasma. Furthermore, the residual content of the parent compound in in vitro experiments was approximately 59%, 5% and barely none in intestinal bacteria, intestinal S9 and simulated intestinal juice at 6 h, respectively.

CONCLUSIONS

The present work has demonstrated that the factors causing the poor bioavailability of isoacteoside should be attributed to the metabolism. In general, the metabolism that resulted from intestinal flora and intestinal enzymes were predominant reasons giving rise to the poor bioavailability of ISAT, which also suggested that metabolites might be responsible for the excellent pharmacological effect of ISAT. Copyright © 2016 John Wiley & Sons, Ltd.

Echinacoside ameliorates the memory impairment and cholinergic deficit induced by amyloid beta peptides via the inhibition of amyloid deposition and toxicology

This study investigates the role of the amyloid cascade and central neuronal function on the protective effects of echinacoside in amyloid β peptide 1-42 (Aβ 1-42)-treated SH-SY5Y cells and an Aβ 1-42-infused rat.

Rapid screening and identification of the differences between metabolites of Cistanche deserticola and C. tubulosa water extract in rats by UPLC-Q-TOF-MS combined pattern recognition analysis

Cistanches Herba is a famous traditional Chinese medicine that has been in use for treating kidney deficiency, impotence, female infertility, morbid leucorrhea, profuse metrorrhagia, and senile constipation. With the exception of studies available for a few single active ingredients such as echinacoside, acteoside, and poliumoside, comprehensive and systematic studies on in vivo metabolism of Cistanches Herba are lacking despite its widespread clinical application. There is no comparative study yet on the metabolites resulting from the traditional usage of Cistanche deserticola and C. tubulosa water extract - two species that are recorded in Chinese Pharmacopoeia. This further restricts research on the therapeutic effect of Cistanches Herba to a great extent. In this study, a robust and unbiased UPLC-Q-TOF-MS combined pattern recognition analysis (orthogonal partial least squared discriminant analysis, OPLS-DA) was employed to rapidly screen prototype components and metabolites of C. deserticola and C. tubulosa water extract in rat urine, feces, and serum. A total of 71 metabolites from C. deserticola including 25 prototype components and 46 metabolites, and 45 metabolites from C. tubulosa including 18 prototype components and 27 metabolites were tentatively identified. Out of these, 10 metabolites were characterized for the first time in these two species. Results of this study indicate that phenylethanoid glycosides (PhGs) are mainly metabolized into degradation products in the gastrointestinal tract of rats. The chemical components cistanoside B, C, D, and E exist only in C. deserticola and release methylated hydroxytyrosol (HT) following metabolism. This factor contributes to the difference between metabolites of C. deserticola and C. tubulosa water extract in rats and is responsible for the differential therapeutic effect that these two species of Cistanches Herba have on the same diseases.

Phenylethanoid Glycosides: Research Advances in Their Phytochemistry, Pharmacological Activity and Pharmacokinetics

Phenylethanoid glycosides (PhGs) are widely distributed in traditional Chinese medicines as well as in other medicinal plants, and they were characterized by a phenethyl alcohol (C₆-C₂) moiety attached to a β-glucopyranose/β-allopyranose via a glycosidic bond. The outstanding activity of PhGs in diverse diseases proves their importance in medicinal chemistry research. This review summarizes new findings on PhGs over the past 10 years, concerning the new structures, their bioactivities, including neuroprotective, anti-inflammatory, antioxidant, antibacterial and antivirus, cytotoxic, immunomodulatory, and enzyme inhibitory effects, and pharmacokinetic properties.

Systematic characterization of the metabolites of echinacoside and acteoside from Cistanche tubulosa in rat plasma, bile, urine and feces based on UPLC-ESI-Q-TOF-MS

Echinacoside (ECH) and acteoside (ACT), as the most and major active components of Cistanche tubulosa, were reported to possess cardioactive, neuroprotective and hepatocyte protective effects, as well as antibacterial, antioxidative effects. Recently, more studies have focused on their pharmacological activities. However, their metabolic profiles in vivo have not been sufficiently investigated. This study proposes an approach for rapidly identifying the complicated and unpredictable metabolites of ECH and ACT in rat plasma, bile, urine and feces, and systematically and comprehensively revealing their major metabolic pathways, based on powerful ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Plasma, bile, urine and feces were collected from rats after a single 200 mg/kg oral dose. A total of 49 metabolites were detected in rat biological samples. Through analyzing metabolites in bile samples, it was found that ECH and ACT were subjected to a marked hepatic first-pass effect in liver. Copyright © 2016 John Wiley & Sons, Ltd.

The metabolic profile of acteoside produced by human or rat intestinal bacteria or intestinal enzyme in vitro employed UPLC-Q-TOF-MS

Acteoside, the main and representative phenylethanoid glycosides of Herba Cistanches, possesses wide bioactivities but low oral bioavailability. It may serve as the prodrug and be converted into the active forms in gastrointestinal tract, which mainly occurred in intestinal tract composed of intestinal bacteria and intestinal enzyme. Intestinal bacteria, a new drug target, take a significant role on exerting pharmacological effects of drugs by oral administration. In this paper, acteoside was incubated with human or rat intestinal bacteria or rat intestinal enzyme for 36 h to seek metabolites responsible for pharmacodynamics. The samples were analyzed by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Besides the parent compound, 14 metabolites were detected and identified based on their retention times and fragmentation patterns in their MS spectra including 8 degradation metabolites, 2 isomers in intestinal bacteria and intestinal enzyme samples and 4 parent metabolites only found in intestinal enzymes. The metabolic pathway of acteoside was thus proposed. Identification of these metabolites of acteoside by the intestinal bacteria or intestinal enzyme gave an insight to clarify pharmacological mechanism of traditional Chinese medicines and identify the real active molecules.