Pharmacokinetic Comparisons of Different Combinations of Yigan Jiangzhi Formula in Rats: Simultaneous Determination of Fourteen Components by UPLC-MS/MS

Ultra-performance liquid chromatography-tandem mass spectrometry determination and pharmacokinetic studies of five phenolic acids in rat plasma after intravenous administration of salvianolic acid for injection

A simple, efficient, and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for simultaneous determination and pharmacokinetic study of salvianolic acid D, rosmarinic acid, lithospermicic acid, salvianolic acid B, and salvianolic acid Y in rat plasma after intravenous administration of salvianolic acid for injection. Three doses of administration, containing 10, 25, and 62.5 mg/kg, were investigated. Plasma samples were pretreated using protein precipitation with pre-cooled acetonitrile. As shown in S1, Chromatographic separation was achieved on a Waters Acquity UPLC® BEH C18 column (1.7 μm, 2.1 × 100 mm) with a mobile phase composed of acetonitrile-methanol-0.5% aqueous formic acid (10:30:60, v/v/v) at a flow rate of 0.3 ml/min. MS was detected by electrospray ion source negative ion mode and multiple reaction monitoring mode. The method was fully validated. The calibration curves for the five phenolic acids were linear in the given concentration ranges. The extraction recoveries, matrix effects, intra-day and inter-day precisions, and accuracies of the five analytes were all within acceptable limits. No significant difference of elimination half-life time (T_1/2 ) of five analytes at three doses was observed. Area under the curve and peak concentration (C_max ) of the five analytes demonstrated a linear increase in the doses with the linear correlation r of each analyte at three doses being greater than 0.915. It indicated that the pharmacokinetic behavior of is positively related to the dose in the range of 10-62.5 mg/kg.

Simultaneous Determination of Six Components in Beagle Dog Plasma by UPLC-MS/MS and Its Application to a Comparative Pharmacokinetic Study of Three Different Yuanhu Zhitong Preparations

This study has developed a sensitive, simple, and reliable ultrahigh performance liquid chromatography tandem mass spectrometry method for the simultaneous determination of corydaline, tetrahydropalmatine, tetrahydroberberine, tetrahydrocoptisine, byakangelicin, and byakangelicol in beagle dog plasma after oral administration of Yuanhu Zhitong (YHZT) oral liquid, dispersible tablet, and dropping pills. A one-step protein precipitation method was used with methanol-acetonitrile (50 : 50, v/v) for plasma sample pretreatment. Six analytes and one internal standard were separated on a Waters Acquity UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) by gradient elution with 0.1% formic acid-water and 0.1% formic acid-acetonitrile at a flow rate of 0.4 mL/min. Detection was conducted by multiple reaction monitoring mode in the positive ionization. The calibration curves showed good linearity (r > 0.9920). The lower limit of quantization ranged from 0.1 to 1 ng/mL. Moreover, the other results of the method validation were within the acceptable range. After oral administration, the pharmacokinetic characteristics of the three YHZT preparations were different. Compared with the two solid preparations, the absorption of the six analytes in oral liquid was more rapid. Moreover, the area under the plasma drug concentration-time curve and the maximum plasma concentration of tetrahydropalmatine (the main analgesic component of YHZT prescription) in the oral liquid group were higher than those in the other two groups. The results showed oral liquid can exert its efficacy quickly, while dispersible tablet and dropping pills exhibit relatively slow release pattern. The comparative pharmacokinetic study would be helpful to the clinical rational selection and application of YHZT preparations.

Pharmaceutical Values of Calycosin: One Type of Flavonoid Isolated from Astragalus

Astragalus is a popular Materia Medica in China, and it could be applied in the treatment of various diseases. It contains a variety of chemically active ingredients, such as saponins, flavonoids, and polysaccharides. Plant-derived bioactive chemicals are considered natural, safe, and beneficial. Among the infinite plant-identified and isolated molecules, flavonoids have been reported to have positive effects on human health. Calycosin is the most important active flavonoid substance identified predominantly within this medicinal plant. In recent years, calycosin has been reported to have anticancer, antioxidative, immune-modulatory, and estrogenic-like properties. This review collected recent relevant literatures on calycosin and summarized its potential pharmaceutical properties and working mechanism involved, which provided solid basis for future clinical research.

Polyphenols and Cannabidiol Modulate Transcriptional Regulation of Th1/Th2 Inflammatory Genes Related to Canine Atopic Dermatitis

Canine atopic dermatitis (AD) is a multifactorial allergic disease associated with immune and abnormal skin barrier dysfunction and it is one of the primary causes of pruritus. Using a novel in vitro model of AD, here we tried to revert the alteration of transcriptional regulation of AD canine key genes testing a nutraceutical mixture containing flavonoids, stilbene, and cannabinoids, which are already well-known for their applications within dermatology diseases. The nutraceutical mixture induced in inflamed cells a significant downregulation (p < 0.05) of the gene expression of ccl2, ccl17, and tslp in keratinocytes and of ccl2, ccl17, and il31ra in monocytes. Consistent with the observed alterations of tslp, ccl2, ccl17, and il31ra messenger RNA (mRNA) levels, a significant increase (p < 0.05) of DNA methylation at specific CpG sites on the gene regulatory regions was found. These results lay the foundation for the use of these natural bioactives in veterinary medicine and provide a model for deeper understanding of their mechanisms of action, with potential translation to human research.

Analytical determinations of luteolin

Plants, through the photosynthesis process, produce the substances necessary for all the life cycles of nature, which are called "primary metabolites." Moreover, there are some plants that synthesize, in addition to these, other substances with more specific functions, which are known as "secondary metabolites." It is inside this group that flavonoids are located, whose main function is to protect organisms from damage caused by different oxidizing agents. Luteolin (3,4,5,7-tetrahydroxy-flavone) belongs to the sub-class of flavonoids known as flavones and is one of 10,000 flavonoids currently known, being one of the most bio-active flavonoids. Its various beneficial properties for health, together with the increasing reduction in the use of synthetic antioxidants, make the study of luteolin a very active field. Within this, the quantification of this molecule has become a subject of very special interest given that it is transversal to all fields. In this review article, we aim to give the reader a broad and deep vision of this topic, focusing on the events reported in the last 5 years and covering all possible techniques related to analytical determinations. We will discuss in terms of advantages and disadvantages between techniques, selectivity, sensitivity, costs, time consumption, and reagents as well as in the complexity of operations.