Simultaneous determination and pharmacokinetics study of four quinones in rat plasma by ultra high performance liquid chromatography with electrospray ionization tandem mass spectrometry after the oral administration of Qianzhi capsules

Investigation of the factors responsible for the low oral bioavailability of alizarin using a sensitive LC-MS/MS method: In vitro, in situ, and in vivo evaluations

Alizarin (1,2-dihydroxyanthraquinone) is an anthraquinone reddish dye widely used for painting and textile dyeing. As the biological activity of alizarin has recently attracted increasing attention from researchers, its therapeutic potential as complementary and alternative medicine is of interest. However, no systematic research has been conducted on the biopharmaceutical and pharmacokinetic aspects of alizarin. Therefore, this study aimed to comprehensively investigate the oral absorption and intestinal/hepatic metabolism of alizarin using a simple and sensitive tandem mass spectrometry method developed and validated in-house. The present method for the bioanalysis of alizarin has merits, including a simple pretreatment procedure, small sample volume, and adequate sensitivity. Alizarin exhibited pH-dependent moderate lipophilicity and low solubility with limited intestinal luminal stability. Based on the in vivo pharmacokinetic data, the hepatic extraction ratio of alizarin was estimated to be 0.165-0.264, classified as a low level of hepatic extraction. In an in situ loop study, considerable fractions (28.2%-56.4%) of the alizarin dose were significantly absorbed in gut segments from the duodenum to ileum, suggesting that alizarin may be classified as the Biopharmaceutical Classification System class II. An in vitro metabolism study using rat and human hepatic S9 fractions revealed that glucuronidation and sulfation, but not NADPH-mediated phase I reactions and methylation, are significantly involved in the hepatic metabolism of alizarin. Taken together, it can be estimated that the fractions of oral alizarin dose unabsorbed from the gut lumen and eliminated by the gut and liver before reaching the systemic circulation are 43.6%-76.7%, 0.474%-36.3%, and 3.77%-5.31% of the dose, respectively, resulting in a low oral bioavailability of 16.8%. Therefore, the oral bioavailability of alizarin depends primarily on its chemical degradation in the gut lumen and secondarily on first-pass metabolism.

Pharmacokinetics of Anthraquinones from Medicinal Plants

Anthraquinones are bioactive natural products, some of which are active components in medicinal medicines, especially Chinese medicines. These compounds exert actions including purgation, anti-inflammation, immunoregulation, antihyperlipidemia, and anticancer effects. This study aimed to review the pharmacokinetics (PKs) of anthraquinones, which are importantly associated with their pharmacological and toxicological effects. Anthraquinones are absorbed mainly in intestines. The absorption rates of free anthraquinones are faster than those of their conjugated glycosides because of the higher liposolubility. A fluctuation in blood concentration and two absorption peaks of anthraquinones may result from the hepato-intestinal circulation, reabsorption, and transformation. Anthraquinones are widely distributed throughout the body, mainly in blood-flow rich organs and tissues, such as blood, intestines, stomach, liver, lung, kidney, and fat. The metabolic pathways of anthraquinones are hydrolysis, glycuronidation, sulfation, methylation/demethylation, hydroxylation/dehydroxylation, oxidation/reduction (hydrogenation), acetylation and esterification by intestinal flora and liver metabolic enzymes, among which hydrolysis, glycuronidation and sulfation are dominant. Of note, anthraquinones can be transformed into each other. The main excretion routes for anthraquinones are the kidney, recta, and gallbladder. Conclusion: Some anthraquinones and their glycosides, such as aloe-emodin, chrysophanol, emodin, physcion, rhein and sennosides, have attracted the most PK research interest due to their more biological activities and/or detectability. Anthraquinones are mainly absorbed in the intestines and are mostly distributed in blood flow-rich tissues and organs. Transformation into another anthraquinone may increase the blood concentration of the latter, leading to an increased pharmacological and/or toxicological effect. Drug-drug interactions influencing PK may provide insights into drug compatibility theory to enhance or reduce pharmacological/toxicological effects in Chinese medicine formulae and deserve deep investigation.

Pharmacokinetics study of 16 active ingredients from Tabson-2 decoction in normal and d-galactose induced osteoporosis rats by liquid chromatography-tandem mass spectrometry

Tabson-2 decoction is the traditional Mongolian formula for anti-osteoporosis, and the ambiguous of active ingredient is an important factor in restricting its modernization and globalization. Although pharmacokinetic profiles research is a viable approach to find the components being responsible for formula efficacy, the pharmacokinetics study of Tabson-2 decoction has not been elucidated yet. Owing to the existence of isomers, low bioavailability of some small molecule and interference of endogenous, the pharmacokinetics study of Tabson-2 decoction are more difficult than that of chemical drugs. In our experiment, a specific and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for simultaneous determination of 16 active ingredients in Tabson-2 decoction, which could fulfill the requirements of multi-compounds pharmacokinetic study of Tabson-2 decoction. Additionally, the ingredients with significant distributions in rats were gentianic acid, chlorogenic acid, and aucubin, which could be the main potential active components in Tabson-2 decoction. The components with a significant bioavailability difference between normal and d-galactose induced osteoporosis rats were achieved as well. These data offer useful information for screening the active ingredients in Tabson-2 decoction, and assessing the bioavailability of these active ingredients in different physiological status, which might provide a possible mechanism of anti-osteoporosis efficacy of Tabson-2 decoction.

A LC-MS/MS method for simultaneous determination of seven alkaloids in rat plasma after oral administration of Phellodendri chinensis cortex extract and its application to a pharmacokinetic study

A sensitive and rapid liquid chromatography with tandem mass spectrometry method has been developed for simultaneous determination of berberine (I), jateorhizine (II), palmatine (III), tetrahydropalmatine (IV), phellodendrine (V), protopine (VI) and columbamine (VII) in rat plasma after oral administration of Phellodendri chinensis cortex extraction. The plasmas were extracted by liquid-liquid extraction. The tandem mass spectrometric detection was performed in the multiple reaction monitoring mode in the positive ionization. The intra- and interday precisions and accuracies were in range from -12.18 to 13.21%. Mean absolute recoveries of all analytes and internal standard were between 78.6 and 98.9%. The seven alkaloids were proven to be stable during sample storage and analysis procedures. The established method was validated and successfully applied to pharmacokinetics study in rat plasma after oral administration of Phellodendri chinensis cortex extract. The t_1/2 of palmatine, columbamine, pellodendrine, berberine, tetrahydropalmaine, jatrorrhizine, and protopine were 5.16, 5.96, 7.18, 19.84, 6.28, 7.08, 6.90 h, respectively. The seven compounds could be rapidly absorbed into blood (time for maximal concentration, 1.80-1.93 h). This study could establish a foundation for further research of Phellodendri chinensis cortex and might provide more useful information to guide the clinical usage.

Simultaneous Determination and Pharmacokinetics Study of Six Triterpenes in Rat Plasma by UHPLC-MS/MS after Oral Administration of Sanguisorba officinalis L. Extract

A selective and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the determination of ziyuglycoside I (I), 3β,19α-dihydroxyurs-12-en-28-oic-acid 28-β-d-glucopyranosyl ester (II), 3β-[(α-l-arabinopyranosyl) oxy]-urs-12,18(19)-dien-28-oic acid β-d-glucopyranosyl ester (III), rosamultin (IV), 1β-hydroxyeuscaphic acid (V) and alpinoside (VI) in rats after oral administration of Sanguisorba officinalis L. (S. officinalis) extract. The 3β,19α-dihydroxyurs-12-en-28-oic-acid 28-β-d-glucopyranosyl ester, 3β-[(α-l-arabinopyranosyl) oxy]-urs-12,18(19)-dien-28-oic acid β-d-glucopyranosyl ester, rosamultin, 1β-hydroxyeuscaphic acid and alpinoside in rat plasma were the first report in the pharmacokinetics study in the present study. The analytes were quantified using the multiple reaction monitoring (MRM) mode with the electrospray ion source in positive electrospray ionization. Plasma was extracted with ethyl acetate via liquid–liquid extraction. Bifendate was used as internal standard (IS). The current method was validated for linearity, intra-day and inter-day precisions, accuracy, extraction recovery, matrix effect and stability. The lower limits of quantification of ziyuglycoside I, 3β,19α-dihydroxyurs-12-en-28-oic-acid 28-β-d-glucopyranosyl ester, 3β-[(α-l-arabinopyranosyl) oxy]-urs-12,18(19)-dien-28-oic acid β-d-glucopyranosyl ester, rosamultin, 1β-hydroxyeuscaphic acid and alpinoside were 6.1, 4.9, 1.3, 3.8, 1.5 and 5.7 ng/mL, respectively. Intra-day and inter-day precision and the accuracy of the assay were in range from −9.48 to 12.74%. The extraction recoveries of analytes and bifendate (IS) from rat plasma ranged from 77.17% to 92.48%. Six compounds could be rapidly absorbed into blood (T_max, 0.58–1.58 h), and then eliminated relatively slowly (t_1/2, 6.86–11.63 h). The pharmacokinetic results might contribute to further guide the clinical application of S. officinalis.