Online coupling of the Ussing chamber, solid-phase extraction and high-performance liquid chromatography for screening and analysis of active constituents of traditional Chinese medicines

Intestinal Absorption Characteristics and Reciprocal Interactions of Forsythiae Fructus and Lonicerae Japonicae Flos-Containing Chinese Herbal Formulation with Human Gut Microbiome

The intestinal absorption of active herbal constituents plays an important role in the biomedical efficacy of Traditional Chinese Medicine (TCM) formulations after oral administration. TCM compounds with low oral bioavailability can reach the distal intestine and then interact with intestinal flora, influencing the botanical pharmacological effects. In this study, in vitro digestion and an ex vivo Ussing chamber model were utilized to evaluate the intestinal absorption behavior of Forsythiae Fructus-Lonicerae Japonicae Flos-containing Yinqiao Jiedu Granule (YQJDG). It was found that the jejunum exhibited active absorption effects for some components of the formula, while the oral bioavailability of other herbal ingredients was low. Through further research using a combined UPLC-MS/MS and 16S rDNA sequencing technique, we studied the existence of the reciprocal interactions between YQJDG and gut microbiome. The in vitro fecal fermentation results showed that YQJDG significantly impacted the microbial community composition. The YQJDG markedly increased the abundance of beneficial microorganisms, such as Parabacteroides distasonis and Streptococcus gallolyticus subsp. Macedonicus, and suppressed the abundance of conditional pathogens including Prevotella steorerea, Haemophilus parainfluenzae, and Bacteroides. These effects may potentially contribute to the body's immune functions and anti-inflammatory capacities. UPLC-MS/MS analysis suggested that the fecal microbiota chemically transformed constituents with low bioavailability to more readily absorbed potentially active metabolites. These findings provided valuable insights into the absorption characteristics of YQJDG and its interaction with the gut microbiome, further facilitating our understanding of precise pharmacological mechanisms of action of this Chinese herbal formulation.

Physicochemical properties, biological activities, applications, and protective potential of the skeletal system of Eucommia ulmoides polysaccharides: a review

Eucommia ulmoides Oliv (E. ulmoides) is a widely distributed plant with economic value, nutritional value, edible value and even medicinal value. In recent years, E. ulmoides polysaccharides are considered to be one of the most important bioactive ingredients in E. ulmoides. Modern pharmacological studies show that the crude extract of E. ulmoides polysaccharides, their active monomer and ramifications have a wide range of pharmacological activities in vitro and in vivo experiments, which can be used to improve inflammation, regulate immunity, improve osteoporosis, and promote osseointegration, etc. Therefore, this review focuses on the induction and summary of the research at home and abroad in recent years, and summarizes the extraction and purification, modification methods, physicochemical properties, biological activities and potential mechanisms of E. ulmoides polysaccharides, providing a theoretical basis for the in-depth study of E. ulmoides polysaccharides and the development of related products.

Enrichment, Antioxidant and Enzyme Inhibition Activities of Flavonoids from Artemisia Selengensis Turcz

Macroporous resin was used to enrich flavonoids in the ethyl acetate extract of Artemisia Selengensis Turcz. Based on a single factor experiment, the enrichment process was optimized using the response surface method. The optimal parameters of the enrichment process were a sample concentration of 0.3 mg/mL, a loading rate of 1 mL/min, an elution flow rate of 2 mL/min, and a total flavonoid content of 155.38±0.97 mg/g. The flavonoids enriched by AB-8 macroporous resin demonstrated significant scavenging activities against DPPH, ABTS+, and hydroxyl free radicals, and also exhibited certain inhibitory effects on α-amylase and α-glucosidase. Among them, the scavenging ability of the flavonoids enriched by AB-8 macroporous resin on hydroxyl free radical (IC50=30.31±1.92 μg/mL) was the closest to Vc, and the inhibitory effect on α-glucosidase (IC50=16.19±1.35 μg/mL) was the best. These findings confirmed the potential of Artemisia Selengensis Turcz. was a natural antioxidant and hypoglycemic drug.

Preparation of a novel MOF-POPM and its application in online purification and enrichment of oleanolic acid in medicinal plants

In present work, a method for enrichment, purification, and content determination of oleanolic acid (OA) in medicinal plants was established based on on-line solid phase extraction (SPE). A metal organic frameworks-porous organic polymer monolith (MOF-POPM) was prepared with functionalized UiO-66-(OH)2 as monomer and was used as SPE column for online enrichment and purification of OA. The ratio of adsorbent, enriching and eluting solvent, mobile phase pH, and flow rate had been systematically investigated. Under the optimum conditions, the linear range of OA was 0.59-2500 μg/mL with r = 0.9996. The limit of detection (LOD) was 0.18 μg/mL and the limit of quantification (LOQ) was 0.59 μg/mL. The intra-day relative standard deviations (RSDs) and inter-day RSDs of retention time and peak area were less than 0.3% and 1.3%, respectively. The average recoveries of OA in medicinal plants samples ranged from 87.7 to 104.6%. The results demonstrated that the online system was reliable and accurate for enrichment, purification, and content determination of OA in medicinal plants.

A stable core-shell metal-organic framework@covalent organic framework composite as solid-phase extraction adsorbent for selective enrichment and determination of flavonoids

Hydrophobization and stability is crucial for the practical application of most metal-organic frameworks (MOFs) in extraction technique. In this study, a stable core-shell MOF@COF composite (NH2-MIL-101(Fe)@TAPB-FPBA-COF) was successfully prepared by Schiff base reaction and applied to solid-phase extraction (SPE) of hydrophobic flavonoids. Notably, the TAPB-FPBA-COF shell acts as a hydrophobic "shield", which not only improves the hydrophobicity and stability of hydrophilic NH2-MIL-101(Fe), but also makes the extraction efficiency of flavonoids from MOF@COF composite significantly higher than that of pure NH2-MIL-101(Fe) and TAPB-FPBA-COF. In addition, a sensitive analytical method with excellent linearities (0.1-500 ng mL-1, R2 ≥ 0.9967), low limits of detection (0.02-0.04 ng mL-1 for water; 0.04-0.07 ng mL-1 for grape juice; 0.06-0.08 ng mL-1 for honey), good repeatability (intra-day/inter-day precision are 1.86-5.37%/1.82-7.79%, respectively) and only 5 mg of adsorbent per cartridge was established by optimizing the SPE process combined with high performance liquid chromatography with ultraviolet-visible detector (HPLC-UV). Meanwhile, selectivity study and comparative experiments with the commercial C18 adsorbent showed that the MOF@COF adsorbent exhibited satisfactory extraction efficiency for flavonoids due to multiple interactions such as hydrogen bonding, hydrophobic, and π-π interactions. Finally, the good recoveries in grape juice (84.5-102.5%) and honey (87.5-104.6%) samples further validated the applicability of the proposed method in complex samples.

Preparation of Molecularly Imprinted Polymer Microspheres for Selective Solid-Phase Extraction of Capecitabine in Urine Samples

Molecularly imprinted solid-phase extraction to treat biological samples has attracted considerable attention. Herein, molecularly imprinted polymer (MIP) microspheres with porous structures were prepared by a combined suspension-iniferter polymerization method using capecitabine (CAP) as a template molecule. This material was subsequently used as a solid-phase extraction agent to separate and enrich drug molecules in urine samples. UV analysis revealed that methacrylate (MAA) was an ideal functional monomer, and 1H Nuclear Magnetic Resonance (1H NMR), Ultraviolet (UV), and Fourier transform-infrared (FT-IR) spectroscopic analyses were used to study the interaction forces between MAA and CAP, demonstrating that hydrogen bonding was the primary interaction force. MIPs with outstanding selectivity were successfully prepared, and the analysis of their surface morphology and chemical structure revealed a spherical morphology with small holes distributed across a rough surface. This surface morphology significantly reduced the mass transfer resistance of template molecules, providing an ideal template recognition effect. Using the molecularly imprinted solid-phase extraction method, CAP and the structural analog cytidine (CYT) were pretreated in urine samples and quantified by HPLC. The results showed that CAP and CYT recoveries reached 97.2% and 39.8%, respectively, with a limit of detection of 10.0–50.0 µg·mL−1. This study provides a novel approach to drug molecule pretreatment that can be applied in drug separation and functional materials science fields.

Magnetic nanoparticles covalently immobilizing epidermal growth factor receptor by SNAP-Tag protein as a platform for drug discovery

Magnetic nanoparticles (NPs) cloaked with cell membranes expressing high levels of the epidermal growth factor receptor (EGFR) have been used to screen for EGFR-targeting active compounds in traditional Chinese medicine (TCM) formulations. However, previous strategies involved physical immobilization of the biomaterials on the surface of the nanocarrier, resulting in highly unstable platforms since the biological materials could dislodge easily. Chemical bonding of biomaterials to the nanoparticles surface can improve the stability of the biomimetic platforms. In this study, membrane fragments from cells expressing SNAP-Tag-EGFR (ST-EGFR) were immobilized on the surface of magnetic NPs. The ST-EGFR magnetic cell membrane nanoparticles (ST-EGFR/MCMNs) showed greater stability, and higher binding capacity, selectivity adsorption of gefitinib after 7 days compared to the un-immobilized magnetic cell membrane nanoparticles (EGFR/MCMNs). The ST-EGFR/MCMNs were used to screen for the EGFR-targeting active compounds of Zanthoxyli Radix (ZR), and identified toddalolactone and nitidine chloride. The latter significantly inhibited the proliferation of EGFR-overexpressing cancer cells, and was more effective compared to gefitinib. This innovative technology can be used to rapidly screen for active compounds from complex extracts, and aid in drug discovery.

Preliminary screening of the potential active ingredients in traditional Chinese medicines using the Ussing chamber model combined with HPLC-PDA-MS

An in vitro intestinal absorption model combined with high-performance liquid chromatography-photo diode array-tandem mass spectrometry (HPLC-PDA-MS) was used for preliminary screening of potential active ingredients from complex multi-component traditional Chinese medicine (TCM) system. Oral administration is one of the main administration methods for TCMs. Only the ingredients that could be absorbed have the opportunity to play a role. Thus, these were defined as potential active ingredients. Studying of intestinal absorption can provide a theoretical basis for the mechanism of TCMs. The Caco-2 cell model, the everted rat gut sac model, and the Ussing chamber model were established for TCMs. The degree of anastomosis between the in vitro intestinal model and the actual intestinal absorption of TCMs were evaluated by the gavage method in rats. The Ussing chamber model was best fit for oral experiments in rats and was selected as the research means to preliminarily screen potential active ingredients from eight TCMs, including Salvia miltiorrhiza Bunge, Astragalus propinquus Schischkin, Plantago asiatica L, Fallopia multiflora (Thunb.) Harald, Epimedium brevicornu Maxim, Moutan Cortex, Citrus reticulata Blanco, and Panax notoginseng (Burkill) F. H. Chen ex C. H. Chow. A total of 44 components were absorbed and screened as the potential active ingredients from the 80 components identified in eight TCMs by HPLC-PDA-MS.