Simultaneous determination of seven alkaloids from Rhizoma Corydalis Decumbentis in rabbit aqueous humor by LC–MS/MS: Application to ocular pharmacokinetic studies

Mining Therapeutic Efficacy from Treasure Chest of Biodiversity and Chemodiversity: Pharmacophylogeny of Ranunculales Medicinal Plants

Ranunculales, comprising of 7 families that are rich in medicinal species frequently utilized by traditional medicine and ethnomedicine, represents a treasure chest of biodiversity and chemodiversity. The phylogenetically related species often have similar chemical profile, which makes them often possess similar therapeutic spectrum. This has been validated by both ethnomedicinal experiences and pharmacological investigations. This paper summarizes molecular phylogeny, chemical constituents, and therapeutic applications of Ranunculales, i.e., a pharmacophylogeny study of this representative medicinal order. The phytochemistry/metabolome, ethnomedicine and bioactivity/pharmacology data are incorporated within the phylogenetic framework of Ranunculales. The most studied compounds of this order include benzylisoquinoline alkaloid, flavonoid, terpenoid, saponin and lignan, etc. Bisbenzylisoquinoline alkaloids are especially abundant in Berberidaceae and Menispermaceae. The most frequent ethnomedicinal uses are arthritis, heat-clearing and detoxification, carbuncle-abscess and sore-toxin. The most studied bioactivities are anticancer/cytotoxic, antimicrobial, and anti-inflammatory activities, etc. The pharmacophylogeny analysis, integrated with both traditional and modern medicinal uses, agrees with the molecular phylogeny based on chloroplast and nuclear DNA sequences, in which Ranunculales is divided into Ranunculaceae, Berberidaceae, Menispermaceae, Lardizabalaceae, Circaeasteraceae, Papaveraceae, and Eupteleaceae families. Chemical constituents and therapeutic efficacy of each taxonomic group are reviewed and the underlying connection between phylogeny, chemodiversity and clinical uses is revealed, which facilitate the conservation and sustainable utilization of Ranunculales pharmaceutical resources, as well as developing novel plant-based pharmacotherapy.

Simultaneous qualitative and quantitative analysis of eight alkaloids in Corydalis Decumbentis Rhizoma (Xiatianwu) and Corydalis Rhizoma (Yanhusuo) by HPLC and high-resolution MS combined with chemometric methods

In this study, we established a comprehensive high-performance liquid chromatography coupled with diode array detection and high-resolution mass spectrometry method to identify ten and quantified eight constituents in Corydalis Decumbentis Rhizoma ('Xiatianwu' in Chinese) and Corydalis Rhizoma ('Yanhusuo' in Chinese). Chemometric methods were applied to distinguish the botanical origins of the Xiatianwu and Yanhusuo samples. Chromatographic separation was achieved using an Agilent Poroshell EC-C₁₈ column with mobile phases A (1000 mL of 0.2% acetic acid solution containing 2.8 mL of triethylamine) and B (acetonitrile) and stepwise gradient elution. The analytical method was fully validated in terms of linearity, sensitivity, intra- and interday precision and repeatability, limit of detection, limit of quantitation and recovery. Twenty-six Xiatianwu samples and ten Yanhusuo samples were analysed for quality evaluation. In addition, hierarchical clustering analysis and principal component analysis were used to discriminate among samples of different botanical origins. The results showed that the contents of eight alkaloids in Xiatianwu and Yanhusuo were significantly different. Moreover, it was found that chemometric methods could be applied to accurately distinguish these two often conflated Chinese medicinal materials. In conclusion, this study provides a relatively comprehensive method for botanical origin identification and Xiatianwu and Yanhusuo quality control. This article is protected by copyright. All rights reserved.

An integrated strategy for comprehensive characterization of metabolites and metabolic profiles of bufadienolides from Venenum Bufonis in rats

Comprehensive characterization of metabolites and metabolic profiles in plasma has considerable significance in determining the efficacy and safety of traditional Chinese medicine (TCM) in vivo. However, this process is usually hindered by the insufficient characteristic fragments of metabolites, ubiquitous matrix interference, and complicated screening and identification procedures for metabolites. In this study, an effective strategy was established to systematically characterize the metabolites, deduce the metabolic pathways, and describe the metabolic profiles of bufadienolides isolated from Venenum Bufonis in vivo. The strategy was divided into five steps. First, the blank and test plasma samples were injected into an ultra-high performance liquid chromatography/linear trap quadrupole-orbitrap-mass spectrometry (MS) system in the full scan mode continuously five times to screen for valid matrix compounds and metabolites. Second, an extension-mass defect filter model was established to obtain the targeted precursor ions of the list of bufadienolide metabolites, which reduced approximately 39% of the interfering ions. Third, an acquisition model was developed and used to trigger more tandem MS (MS/MS) fragments of precursor ions based on the targeted ion list. The acquisition mode enhanced the acquisition capability by approximately four times than that of the regular data-dependent acquisition mode. Fourth, the acquired data were imported into Compound Discoverer software for identification of metabolites with metabolic network prediction. The main in vivo metabolic pathways of bufadienolides were elucidated. A total of 147 metabolites were characterized, and the main biotransformation reactions of bufadienolides were hydroxylation, dihydroxylation, and isomerization. Finally, the main prototype bufadienolides in plasma at different time points were determined using LC-MS/MS, and the metabolic profiles were clearly identified. This strategy could be widely used to elucidate the metabolic profiles of TCM preparations or Chinese patent medicines in vivo and provide critical data for rational drug use.

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Extension-mass defect filter model could reduce about 39% interfering ions.

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The optimized acquisition mode enhanced about 4 times acquisition capability than regular DDA mode.

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147 metabolites were characterized with metabolic network prediction, and the metabolic pathways were deduced in plasmas.

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The quantitative method of 14 prototypes was established by LC-MS/MS for metabolic profiles study.

Determination of Selected Isoquinoline Alkaloids from Mahonia Aquifolia; Meconopsis Cambrica; Corydalis Lutea; Dicentra Spectabilis; Fumaria Officinalis; Macleaya Cordata Extracts by HPLC-DAD and Comparison of Their Cytotoxic Activity

Alkaloids have protective functions for plants and can play an important role in living organisms. Alkaloids may have a wide range of pharmacological activities. Many of them have cytotoxic activity. Nowadays, cancer has become a serious public health problem. Searching for effective drugs with anticancer activity is one of the most significant challenges of modern scientific research. The aim of this study was the investigation of cytotoxic activity of extracts obtained from Corydalis lutea root and herb, Dicentra spectabilis root and herb, Fumaria officinalis, Macleaya cordata leaves and herb, Mahonia aquifolia leaves and cortex, Meconopsis cambrica root and herb on FaDu, SCC-25, MCF-7, and MDA-MB-231 cancer cell lines. The cytotoxic activity of these extracts has not been previously tested for these cell lines. The aim was also to quantify selected alkaloids in the investigated extracts by High Performance Liquid Chromatography (HPLC). The analyses of alkaloid content were performed using HPLC in reversed phase (RP) mode using Polar RP column and mobile phase containing acetonitrile, water and ionic liquid (IL). Cytotoxic effect of the tested plant extracts and respective alkaloid standards were examined using human pharyngeal squamous carcinoma cells (FaDu), human tongue squamous carcinoma cells (SCC-25), human breast adenocarcinoma cell line (MCF-7), human triple-negative breast adenocarcinoma cell line (MDA-MB-231). All investigated plant extracts possess cytotoxic activity against tested cancer cell lines: FaDu, SCC-25, MCF-7, and MDA-MB-231. The highest cytotoxic activity against FaDu, SCC-25, and MCF-7 cell lines was estimated for Macleaya cordata leaf extract, while the highest cytotoxic activity against MDA-MB-231 cell line was obtained for Macleaya cordata herb extract. Differences in cytotoxic activity were observed for extracts obtained from various parts of investigated plants. In almost all cases the cytotoxic activity of investigated plant extracts, especially at the highest concentration against tested cell lines was significantly higher than the activity of anticancer drug etoposide. Our investigations exhibit that these plant extracts can be recommended for further in vivo experiments to confirm their anticancer activity.

Pharmacokinetics and tissue distribution study of bisabolangelone from Angelicae Pubescentis Radix in rat using LC-MS/MS

A sensitive and accurate LC-MS/MS method was established for quantifying bisabolangelone in rat plasma and tissues. Bisabolangelone was isolated and purified from Angelicae Pubescentis Radix. The pharmacokinetic and tissue distribution of bisabolangelone after administration to rat was performed by LC-MS/MS. Separation was carried out on a C₈ (4.6 × 100 mm, 1.8 μm) column. The MS/MS transitions of bisabolangelone and tussilagone (internal standard) were set at m/z 249.1 → 109.1 and m/z 391.4 → 217.4, respectively. The lower limit of quantification in plasma and other tissues ranged from 1 to 4 ng/mL. The biosamples were prepared using protein precipitation method with acetonitrile. The recovery was >92%. The results showed that values of maximum concentrations and area under the curve depended linearly on the studied doses (2.5, 5 and 7.5 mg/kg body weight). The other ingredients in Angelicae Pubescentis Radix extract possibly reduce the absorption of bisabolangelone in rat. Tissue distribution revealed that bisabolangelone was widely distributed in vivo. The highest and lowest concentrations of bisabolangelone were found in the stomach and in the brain, respectively. It was concluded that the newly established HPLC-MS/MS method was suitable to describe the pharmacokinetic characteristics of bisabolangelone in rat after administration.

Pharmacokinetic study of sirolimus ophthalmic formulations by consecutive sampling and liquid chromatography-tandem mass spectrometry

Sirolimus is regarded as one of the most effective immunosuppressants receiving extensive attention over the years, for which the ocular application needs further development in clinical keratoplasty. In order to study the transcorneal absorption effect of ophthalmic administration, there was a need to study the pharmacokinetics of drugs in aqueous humor. In this work, a validated and reliable HPLC-ESI-MS/MS method was established to study the pharmacokinetics of sirolimus nanoformulations in rabbit aqueous humor. The analysis conditions were as follows. Ascomycin was chosen as internal standard. After a simple precipitation extraction procedure, the aqueous humor samples were separated on a XBridge C18 column (4.6 mm × 150 mm, 3.5 μm, Waters Co., USA) with a mobile phase comprised of water (0.1% formic acid and 5 mM ammonium formate) and methanol (0.1% formic acid) at the ratio of 10:90 (v/v). The mass analysis was achieved by positive ionization with multiple reaction monitoring (MRM) mode. The highest response ion pairs m/z at 931.5→864.5 were chosen for sirolimus. The validated results showed that the calibration range was 0.3-100.6 ng/mL with r = 0.9997 (n = 6). The R.S.D. values of the intra- and inter-day precision were less than 11% and the average accuracy values were between 94.73%-100.20%. Besides, for reducing the consumption of rabbits and the variation of the data, we designed a consecutive sampling method in pharmacokinetic study, with only seven rabbits consumed for each formulation. In conclusion, the developed analysis method was more reliable and practical than previously reported experiments. Meanwhile, the validated method was successfully applied to study the pharmacokinetics of sirolimus micelle and sirolimus nanosuspension after ophthalmic administration.

Ocular bioanalysis: challenges and advancements in recent years for these rare matrices

There are many ocular diseases still presenting unmet medical needs. Therefore, new ophthalmologic drugs are being developed. Bioanalysis of eye compartments (along with plasma and other tissues) is important to determine exposure of the target organ to the drug and to help interpret local pharmacological or toxic effects. This review article identifies several challenges that occur within ocular bioanalysis. They include sample collection and preparation, analytical issues, sourcing control matrix, data interpretation and regulatory requirements. It summarizes how these challenges have been recently addressed, how research has advanced and which questions remain unanswered. Recommendations are made based on the literature and our practical experience within ocular bioanalysis and future perspectives are discussed.