Simultaneous Determination of Multiple Components in Guanjiekang in Rat Plasma via the UPLC-MS/MS Method and Its Application in Pharmacokinetic Study

Development of an indirect competitive enzyme-linked immunosorbent assay for formononetin and its application in a cell-based assay using MC3T3-E1 cells

Formononetin (FMN) is a methoxy isoflavone found abundantly in leguminous plants and associated foods. Several analytical methods have been developed to detect FMN. However, they are costly, complicated, and time-consuming. This study describes an indirect competitive enzyme-linked immunosorbent assay (icELISA) to determine FMN content in food samples using a monoclonal antibody (mAb) against FMN produced by a newly established hybridoma cell line. Validation studies were conducted, and this assay was found to be sufficiently reliable, with an analytical measurement range of 19.53-1250 ng/mL and a detection limit of 17.42 ng/mL. Furthermore, icELISA was successfully applied for a cell-based assay in which the amount of FMN and ononin uptake was quantified in MC3T3-E1 cells. Hence, icELISA is a simple and reliable method for the detection and quantification of FMN, as well as elucidation of its functions and underlying mechanisms of action.

Recent Insights Into the Protective Mechanisms of Paeoniflorin in Neurological, Cardiovascular, and Renal Diseases

ABSTRACT

The monoterpene glycoside paeoniflorin (PF) is the principal active constituent of the traditional Chinese herbal medicines, Radix Paeoniae Alba and Radix Paeoniae Rubra, which have been used for millennia to treat cardiovascular diseases (eg, hypertension, bleeding, and atherosclerosis) and neurological ailments (eg, headaches, vertigo, dementia, and pain). Recent evidence has revealed that PF exerts inhibitory effects on inflammation, fibrosis, and apoptosis by targeting several intracellular signaling cascades. In this review, we address the current knowledge about the pharmacokinetic properties of PF and its molecular mechanisms of action. We also present results from recent preclinical studies supporting the utility of PF for the treatment of pain, cerebral ischemic injury, and neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Moreover, new evidence suggests a general protective role of PF in heart attack, diabetic kidney, and atherosclerosis. Mechanistically, PF exerts multiple anti-inflammatory actions by targeting toll-like receptor-mediated signaling in both parenchymal and immune cells (in particular, macrophages and dendritic cells). A better understanding of the molecular actions of PF may lead to the expansion of its therapeutic uses.

Study on the Pharmacokinetic Profiles of Three Ingredients in Qilong Capsules and Their Potential Interactions in Rats by LC-MS/MS

 

Qilong capsule (QLC) is a well-known Traditional Chinese Medicine, and it has a long history for the treatment of ischemic stroke. Its major ingredients are saponins, such as paeoniflorin, amygdalin and calycosin-7-glucoside, contributing to vasodilation function. In this study, a simple, rapid and sensitive high-performance liquid chromatography-tandem mass spectrometry method was developed to determine three bioactive ingredients in rat plasma after oral administration of QLC. A simple acetonitrile precipitation method was introduced during the sample preparation. Chromatographic separation was performed on a Shiseido CAPCELL PAC MGIII-C18 column using a gradient elution with acetonitrile and water (0.1% formic acid) as a mobile phase, and the chromatographic separation was 5 min. The methodological evaluation showed that this method had a high sensitivity (the lower limit of quantification was 1 ng/mL for calycosin-7-glucoside, 5 ng/mL for paeoniflorin, 5 ng/mL for amygdalin), satisfactory accuracy (relative error ≤ ±15%) and precision (relative standard deviation ≤15%). Then, the analytical method was applied to the pharmacokinetic study in rats following oral administration of the extracts in QLC. Meanwhile, the pharmacokinetic parameters of complex system in QLC were analyzed and the potential interaction between ingredients was explored. The present quantification method and pharmacokinetic study will provide a meaningful reference for the formulas research of QLC in the treatment of ischemic stroke.

HIGHLIGHT

Simultaneous Determination of Six Alkaloids in Rat Plasma by SPE-HPLC-MS/MS and Their Pharmacokinetics after Oral Administration of Radix aconiti Preparata Extract

Simultaneous determination of the content of six alkaloids (aconitine, hypoaconitine, mesaconitine, benzoylaconine, benzoylhypaconine, and benzoylmesaconine) in rat plasma is enabled by HPLC-MS/MS combined with microsolid phase extraction (micro-SPE). To study its pharmacokinetics in rat plasma, the extracted plasma sample was passed through a C18 extraction column and eluted with acetonitrile. The six alkaloids in the Radix aconiti Preparata extract can be completely separated as peaks with good shape. The six components in the plasma sample showed a good linear relationship within their respective linear ranges (R ² > 0.997). The analysis of the six alkaloids can be completed within 20 min. This method has high intraday and interday precision, and the room temperature stability and freeze-thaw stability are good. The matrix effect of the plasma samples is between 86.4 and 114%. The metabolism of the six Aconitum alkaloids in plasma is analyzed using a two-compartment model, which is characterized by fast absorption, slow elimination, and good linear fit, R ² > 0.99. The peak time (T _max) for aconitine, hypaconitine, and neoaconitine ranged from 29.95 to 42.07 min, while the peak time (T _max) for benzoaconitine, benzohypaconitine, and benzoxinaconitine ranged from 42.88 to 73.08 min. With the increased dosage, the bioavailability of Aconitum alkaloids decreased gradually. The method for the determination of Aconitum alkaloids in rat plasma by high performance liquid chromatography-tandem mass spectrometry is sensitive and accurate, which is suitable for rat plasma analysis. The results provide a scientific basis for metabolic study of Aconitum alkaloids in vivo, and pave the way for clinical use of Aconitum medicinal materials and extracts.

Deciphering the pharmacological mechanism of Guan-Jie-Kang in treating rat adjuvant-induced arthritis using omics analysis

Traditional Chinese medicine (TCM) formulas have attracted increasing attention worldwide in the past few years for treating complex disease including rheumatoid arthritis. However, their mechanisms are complex and remain unclear. Guan-Jie-Kang (GJK), a prescription modified from "Wu Tou Decoction," was found to significantly relieve arthritis symptoms in rats with adjuvant-induced arthritis after 30-day treatment, especially in the 24 g/kg/day group. By analyzing 1749 targets related to 358 compounds in the five herbs of GJK, we identified the possible anti-arthritis pathways of GJK, including the calcium signaling and metabolic pathways. Bone damage levels were assessed by micro-computed tomography, and greater bone protective effect was observed with GJK treatment than with methotrexate. Receptor activator of nuclear factor κB ligand (RANKL)-RANK signaling, which is related to calcium signaling, was significantly regulated by GJK. Moreover, a target metabolomics assay of serum was conducted; 17 metabolic biomarkers showed significant correlations with treatment. An integrated pathway analysis revealed that pyruvate metabolism, purine metabolism, and glycolysis metabolism were significantly associated with the effects of GJK in arthritis treatment. Thus, this study establishes a new omics analytical method integrated with bioinformatics analysis for elucidating the multi-pathway mechanisms of TCM.

A gene catalogue of the Sprague-Dawley rat gut metagenome

Background

Laboratory rats such as the Sprague-Dawley (SD) rats are an important model for biomedical studies in relation to human physiological or pathogenic processes. Here we report the first catalog of microbial genes in fecal samples from Sprague-Dawley rats.

Findings

The catalog was established using 98 fecal samples from 49 SD rats, divided in 7 experimental groups, and collected at different time points 30 days apart. The established gene catalog comprises 5,130,167 non-redundant genes with an average length of 750 bp, among which 64.6% and 26.7% were annotated to phylum and genus levels, respectively. Functionally, 53.1%, 21.8%,and 31% of the genes could be annotated to KEGG orthologous groups, modules, and pathways, respectively.

Conclusions

A comparison of rat gut metagenome catalogue with human or mouse revealed a higher pairwise overlap between rats and humans (2.47%) than between mice and humans (1.19%) at the gene level. Ninety-seven percent of the functional pathways in the human catalog were present in the rat catalogue, underscoring the potential use of rats for biomedical research.

Pharmacokinetics and Bioavailability of the Isoflavones Formononetin and Ononin and Their in Vitro Absorption in Ussing Chamber and Caco-2 Cell Models

Formononetin and its glycoside ononin are bioactive isoflavones widely present in legumes. The present study investigated the pharmacokinetics, bioavailability, and in vitro absorption of formononetin and ononin. After an oral administration to rats, formononetin showed a higher systemic exposure over ononin. The oral bioavailability of formononetin and ononin were 21.8% and 7.3%, respectively. Ononin was more bioavailable than perceived, and its bioavailability reached 21.7% when its metabolite formononetin was taken into account. Both formononetin and ononin exhibited better absorption in large intestine segments than that in small intestine segments. Formononetin displayed a better permeability in all intestinal segments over ononin. Transport of formononetin across Caco-2 cell monolayer was mainly through passive diffusion, while ononin was actively pumped out by MRP2 but not P-gp. The results provide evidence for better understanding of the pharmacological actions of formononetin and ononin, which advocates more in vivo evaluations or human trials.

Application of Soluplus to Improve the Flowability and Dissolution of Baicalein Phospholipid Complex

In this study, a novel ternary complex system (TCS) composed of baicalein, phospholipids, and Soluplus was prepared to improve the flowability and dissolution for baicalein phospholipid complex (BPC). TCS was characterized using differential scanning calorimetry (DSC), infrared spectroscopy (IR), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The flowability, solubility, oil–water partition coefficient, in vitro dissolution, and in vivo pharmacokinetics of the system were also evaluated. DSC, IR, PXRD, and SEM data confirmed that the crystal form of baicalein disappeared in BPC and TCS. Furthermore, the angle of repose of TCS of 35° indicated an improvement in flowability, and solubility increased by approximately eight-fold in distilled water when TCS was compared with BPC (41.00 ± 4.89 μg/mL vs. 5.00 ± 0.16 μg/mL). Approximately 91.24% of TCS was released at the end of 60 min in 0.5% SDS (pH = 6.8), which suggested that TCS could improve the dissolution velocity and extent. Moreover, TCS exhibited a considerable enhancement in bioavailability with higher peak plasma concentration (25.55 μg/mL vs. 6.05 μg/mL) and increased AUC_0–∞ (62.47 μg·h/mL vs. 50.48 μg·h/mL) with 123.75% relative bioavailability compared with BPC. Thus, Soluplus achieved the purpose of improving the flowability and solubility of baicalein phospholipid complexes. The application of Soluplus to phospholipid complexes has great potential.