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Background: Gelsemium elegans (G. elegans) has been shown to have strong pharmacological and pharmacodynamic effects in relevant studies both in China and USA. G. elegans has been used as a traditional medicine to treat a variety of diseases and even has the potential to be an alternative to laboratory synthesized drugs. However, its toxicity severely limited its application and development. At present, there is little attention paid to protein changes in toxicity. Aim: This study investigated the toxicity effects after long-term exposure of G. elegans of the rat brain through proteomic. Methods: : 11 differential abundance proteins were detected, among which 8 proteins were higher in the G. elegans- exposure group than in the control group, including Ig-like domain-containing protein (N/A), receptor-type tyrosine-protein phosphatase C (Ptprc), disheveled segment polarity protein 3 (Dvl3), trafficking protein particle complex 12 (Trappc12), seizure-related 6 homologlike (Sez6l), transmembrane 9 superfamily member 4 (Tm9sf4), DENN domain-containing protein 5A (Dennd5a) and Tle4, whereas the other 3 proteins do the opposite including Golgi to ER traffic protein 4 (Get4), vacuolar protein sorting 4 homolog B (Vps4b) and cadherin-related 23 (CDH23). Furthermore, we performed validation of WB analysis on the key protein CDH23. Results: Finally, only fewer proteins and related metabolic pathways were affected, indicating that there was no accumulative toxicity of G. elegans. G. elegans has the potential to develop and utilize of its pharmacological activity. CHD23, however, is a protein associated with hearing. Conclusion: Whether the hearing impairment is a sequela after G. elegans exposure remains to be further studied.

To develop a powerful integrated strategy based on liquid chromatography coupled with mass spectrometry (LC-MS) systems for the comprehensive characterization and quantification of multiple components of herbal medicines.

Background: Gelsemium is a toxic flowering plant of the Gelsemiaceae family. It is used to treat skin diseases in China, and it is an important medicinal and homeopathic plant in North America. Up to now, more than 200 compounds have been isolated and reported from Gelsemium. More than 120 of these are indole alkaloids, including the main components, koumine, gelsemine and humantenmine which produce the pharmacological and toxicological effects of Gelsemium. However, their clinical application their limited by its narrow therapeutic window. Therefore, it is very important to study the metabolism and disposition of indole alkaloids from Gelsemium before their clinical application. This paper reviews all the reports on the metabolism and disposition of alkaloids isolated from Gelsemium at home and abroad. Methods: The metabolism and disposition of alkaloids from Gelsemium were searched by the Web of Science, NCBI, PubMed and some Chinese literature databases. Results: Only koumine, gelsemine and humantenmine have been reported, and few other alkaloids have been described. These studies indicated that the three indole alkaloids are absorbed rapidly, widely distributed in tissues, extensively metabolized and rapidly eliminated. There are species differences in the metabolism of these alkaloids, which is the reason for the differences in their toxicity in animals and humans. Conclusion: This review not only explains the pharmacokinetics of indole alkaloids from Gelsemium but also facilitates further study on their metabolism and mechanism of toxicity.

Currently, the identification of herb metabolites is challenging due to a lack of clear standards. Here, using Gelsemiumas an example, we present a protocol for characterizing target components of herbs. This approach utilizes high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry guided by an in-house herb metabolite database based on reported studies and mass spectrometry. We describe steps for creating an in-house database, preparing and detecting samples, processing data, and characterizing compounds. This approach offers a reference for future research on the identification of herb metabolites.

Previous studies show that several pathways are involved in sanguinarine-induced apoptotic cell death, including AKT downregulation, inhibition of NF-kB activation, mediation of ROS production, downregulation of anti-apoptosis proteins XIAP and cIAP-1, upregulation of BAX, and downregulation of BCL2. In this study, we found out that the quenching of ROS generation by N-acetyl-l-cysteine (NAC), a scavenger of ROS, reversed sanguinarine-induced apoptosis effects, also we found out that sanguinarine-induced rat hepatic stellate T6 cells (HSC-T6 cells) apoptosis was correlated with the generation of increased ROS, which was followed by the activation of caspase-8 (-3, -6, and -9), and the decreasing in the miltochondrial membrane potential (MMP) and the down-regulation of anti-apoptotic protein Bcl-2. It is not clear whether BCL2's downregulation relates to its promoter methylation and miR-15a/16-1 expression which can bind to BCL2 3′-UTR (un-translation reagon). We showed that sanguinarine-induced down regulation of BCL2 was associated with the increased methylation rate of BCL2 promotor district and the increased expression of miR-15a/16-1. HSC-T6 cells treatment with 5-Aza-2'-deoxycytidine (5′-Aza-CdR) impeded sanguinarine-induced BCL2 promotor district methylation and recovered BCL2's expression. Over expression of BCL2 using pEGFP-N1 vector decreased sanguinarine-induced HSC-T6 cells apoptotic death significantly but not completely. These observations clearly showed that BCL2 down regulation was associated with its promoter methylation and miR-15a/16-1 upregulation in sanguinarine-induced Rat HSC-T6 cells.

The aim of this article is to get an overview of the metabolism of quinoxaline 1,4-di-N-oxides (QdNOs) used in food animals. The derivatives of QdNOs (carbadox, olaquindox, mequindox, quinocetone, and cyadox) are the potent synthetic antimicrobial agents that are used for improving the feed efficiency and controlling dysentery in food-producing animals. Studies have demonstrated that the toxicity of QdNOs is closely associated with the production of their metabolism, especially with the production of their reduced metabolites. To the best of our knowledge, no one has systematically compiled the metabolism data of QdNOs. Therefore, the metabolism of QdNOs in animals has been discussed in the review for the first time. These drugs undergo extensive metabolism prior to excretion. N-oxide group reduction is the major metabolic pathway of QdNOs. Moreover, the N1- and N4-oxide reductions of QdNOs by different reducing mechanisms are also described. Obvious differences in metabolic pathways for QdNOs were observed owing to the differences on the side chain of these drugs. Therefore, understanding the metabolic pathways of QdNOs in animals will provide the guides for further studies of metabolism and toxicology of these drugs, and will also provide abundant information for the food safety assessment.

Background: Sanguinarine (SA) is a quaternary benzo[c]phenanthridine alkaloid that is mainly present in the Papaveraceae family. SA has been extensively studied because of its antimicrobial, anti-inflammatory, antitumor, antihypertensive, antiproliferative and antiplatelet activities. Metabolic studies demonstrated that SAbioavailability is apparently low, and the main pathway of SAmetabolism is iminium bond reduction resulting in dihydrosanguinarine (DHSA) formation. Nevertheless, the metabolic enzymes involved in SA reduction are still not known in detail. Thus, the aim of this study was to investigate the rat liver microsomes and cytosolinduced SA iminium bond reduction, and to examine the effects of cytosol reductase inhibitors on the reductive activity. Methods: DHSAformation was quantified by HPLC. The possible enzymes responsible for DHSAformation were examined using selective individual metabolic enzyme inhibitors. Results: When SA was incubated with liver microsomes and cytosol in the absence of NAD(P)H, DHSA, the iminium bond reductive metabolite was formed. The reductase activity of the liver microsomes and cytosol was also enhanced significantly in the presence of NADH. The amount of DHSAformed in the liver cytosol was 4.6-fold higher than in the liver microsomes in the presence of NADH. The reductase activity in the liver cytosol was inhibited by the addition of flavin mononucleotide and/or riboflavin. Inhibition studies indicated that menadione, dicoumarol, quercetin and 7-hydroxycoumarin inhibited rat liver cytosol-mediated DHSA formation in the absence of NADH. However, only menadione and quercetin inhibited rat liver cytosol-mediated DHSA formation in the presence of NADH. Conclusions: These results suggest that the SAiminium bond reduction proceeds viatwo routes in the liver cytosol. One route is direct non-enzymatic reduction by NAD(P)H, and the other is enzymatic reduction by possible carbonyl and/or quinone reductases in the liver cytosol.