Metabolism of palmatine by human hepatocytes and recombinant cytochromes P450

Hepatic biotransformation of non-psychotropic phytocannabinoids and activity screening on cytochromes P450 and UDP-glucuronosyltransferases

This study examined the biotransformation of phytocannabinoids in human hepatocytes. The susceptibility of the tested compounds to transformations in hepatocytes exhibited the following hierarchy: cannabinol (CBN) > cannabigerol (CBG) > cannabichromene (CBC) > cannabidiol (CBD). Biotransformation included hydroxylation, oxidation to a carboxylic acid, dehydrogenation, hydrogenation, dehydration, loss/shortening of alkyl, glucuronidation and sulfation. CBN was primarily metabolized by oxidation of a methyl to a carboxylic acid group, while CBD, CBG and CBC were preferentially metabolized by direct glucuronidation. The study also screened for the activity of recombinant human cytochromes P450 (CYPs) and UDP-glucuronosyltransferases (UGTs), which could catalyze the hydroxylation and glucuronidation of the tested compounds, respectively. We found that CBD was hydroxylated mainly by CYPs 2C8, 2C19, 2D6; CBN by 1A2, 2C9, 2C19 and 2D6; and CBG by 2B6, 2C9, 2C19 and 2D6. CBC exhibited higher susceptibility to CYP-mediated transformation than the other tested compounds, mainly with CYPs 1A2, 2B6, 2C8, 2C19, 2D6 and 3A4 being involved. Further, CBD was primarily glucuronidated by UGTs 1A3, 1A7, 1A8, 1A9 and 2B7; CBN by 1A7, 1A8, 1A9 and 2B7; CBG by 1A3, 1A7, 1A8, 1A9, 2B4, 2B7 and 2B17; and the glucuronidation of CBC was catalyzed by UGTs 1A1, 1A8, 1A9 and 2B7.

The colonic metabolism differences of main alkaloids in normal and colitis mice treated with Coptis chinensis Franch. and Sophora flavescens Ait. herbal pair using liquid chromatography-high resolution mass spectrometry method combined with chemometrics

Coptis chinensis Franch. and Sophora flavescens Ait. is a herbal pair frequently used in treating ulcerative colitis. However, the bio-disposition profile of the major components in the inflamed gut remains unclear, which is essential to understand the pharmacological material basis of this herb pair. Here we established an integral quantitative and chemometric method to deduce the colonic metabolism differences of this herbal pair in normal and colitis mice. With this LC-MS method, a total of 41 components have been found in the Coptis chinensis Franch. and Sophora flavescens Ait. extract, and 28 metabolites were found in the colon after oral administration. Alkaloid and its phase I metabolites were the main components in the colon of normal and colitis mice. The results of principal component analysis at 6 h after oral administration showed significant colonic metabolism differences between normal and colitis mice. Heamap results showed that colitis induced significant changes in the colonic bio-disposition of this herbal pair extract. In particular, in the context of colitis, the phase I metabolism of berberine, coptisine, jatrorrhizine, palmatine,and epiberberine has been inhibited. These results may provide a basis for understanding the pharmacological material basis of Coptis chinensis Franch. and Sophora flavescens Ait. in treating ulcerative colitis.

Toxicity and toxicokinetics of the ethanol extract of Zuojin formula

Background

Zuojin formula, a traditional Chinese medicine, comprises Coptis chinensis and Evodia rutaecarpa. In our previous study, the total alkaloid extract from Zuojin formula (TAZF) showed potent and improved efficacy. However, its safety and toxicokinetics remain unknown. The objective of this study was to evaluate the safety of repeated administrations of TAZF and investigate the internal exposure of the main components and its relationship with toxic symptoms.

Methods

Sprague–Dawley rats were orally administered TAZF at 0.4, 1.2 and 3.7 g/kg for 28 days, which was followed by a 14-day recovery period. The toxic effects were evaluated weekly by assessing body weight changes, food intake, blood biochemistry and haematological indices, organ weights and histological changes. A total of eight components were detected, including berberine, coptisine, epiberberine, palmatine, jatrorrhizine, columbamine, evodiamine, and rutaecarpine. The toxicokinetic profiles of the eight components were investigated after single and repeated administrations. Linear mixed effect models were applied to analyse the associations between internal exposure and toxic symptoms. Network pharmacology analysis was applied to explore the potential toxic mechanisms.

Results

Compared with the vehicle group, the rats in the low- and medium-dose groups did not show noticeable abnormal changes, while rats in the high-dose group exhibited inhibition of weight gain, a slight reduction in food consumption, abdominal bloating and atrophy of the splenic white pulp during drug administration. The concentration of berberine in plasma was the highest among all compounds. Epiberberine was found to be associated with the inhibition of weight gain. Network pharmacology analysis suggested that the alkaloids might cause abdominal bloating by affecting the proliferation of smooth muscle cells. The benchmark dose lower confidence limits (based on body weight inhibition) of TAZF were 1.27 g/kg (male) and 1.91 g/kg (female).

Conclusions

TAZF has no notable liver or kidney toxicity but carries risks of gastrointestinal and immune toxicity at high doses. Alkaloids from Coptis chinensis are the main plasma components related to the toxic effects of TAZF.

Potential Herb-Drug Interactions in the Management of Age-Related Cognitive Dysfunction

Late-life mild cognitive impairment and dementia represent a significant burden on healthcare systems and a unique challenge to medicine due to the currently limited treatment options. Plant phytochemicals have been considered in alternative, or complementary, prevention and treatment strategies. Herbals are consumed as such, or as food supplements, whose consumption has recently increased. However, these products are not exempt from adverse effects and pharmacological interactions, presenting a special risk in aged, polymedicated individuals. Understanding pharmacokinetic and pharmacodynamic interactions is warranted to avoid undesirable adverse drug reactions, which may result in unwanted side-effects or therapeutic failure. The present study reviews the potential interactions between selected bioactive compounds (170) used by seniors for cognitive enhancement and representative drugs of 10 pharmacotherapeutic classes commonly prescribed to the middle-aged adults, often multimorbid and polymedicated, to anticipate and prevent risks arising from their co-administration. A literature review was conducted to identify mutual targets affected (inhibition/induction/substrate), the frequency of which was taken as a measure of potential interaction. Although a limited number of drugs were studied, from this work, interaction with other drugs affecting the same targets may be anticipated and prevented, constituting a valuable tool for healthcare professionals in clinical practice.

Palmatine as an Agent Against Metabolic Syndrome and Its Related Complications: A Review

Palmatine is a naturally occurring isoquinoline alkaloid with various pharmacological properties. Given its antioxidant and anti-inflammatory properties, palmatine may be able to impede the effects of metabolic syndrome (MetS) and its related diseases triggered by inflammation and oxidative stress. This review summarises the existing literature about the effects of palmatine supplementation on MetS and its complications. The evidence shows that palmatine could protect against MetS, and cardiovascular diseases, osteoporosis and osteoarthritis, which might be associated with MetS. These protective effects are mediated by the antioxidant and anti-inflammatory properties of palmatine. Although preclinical experiments have demonstrated the efficacy of palmatine against MetS and its related diseases, no human clinical trials have been performed to validate these effects. This research gap should be bridged to validate the efficacy and safety of palmatine supplementation in protecting humans against MetS and its related diseases.

Electrochemical microreactor combined with mass spectrometry for online oxidation and real-time detection of alkaloids

The main purpose of the present study was to investigate the prototypes and oxidation products of alkaloids with the use of an online electrochemistry/quadrupole time-of-flight mass spectrometry system. The metabolism of oxidative phase I and II was simulated in an electrochemical reaction cell. The metabolic processes for coptisine and jatrorrhizine were simulated in a thin-layer cell fitted with a glassy carbon working electrode, while the metabolic processes for berberine and palmatine were simulated by using a boron-doped diamond working electrode. By using the new experimental system, dehydrogenation, demethylation, methylation, hydroxylation, and the formation of two hydroxylation adducts were detected by applying different potentials to the electrochemical cell. The online reaction with glutathione yielded different covalent glutathione adducts. The results obtained from the electrochemical simulation were found to be in good accordance with those reported previously in vivo, showing that electrochemistry/mass spectrometry is an effective tool for studying metabolic reactions for various complex components. Moreover, analysis of alkaloids in liver microsomes by liquid chromatography coupled with mass spectrometry confirmed the possibility of using an electrochemistry technique to simulate the metabolism of target compounds.

Screening for natural inhibitors of 5-lipoxygenase from Zi-shen pill extract by affinity ultrafiltration coupled with ultra performance liquid chromatography-mass spectrometry

ETHNOPHARMACOLOGICAL RELEVANCE

Zi-shen pill (ZSP), a traditional Chinese medicine, is widely used for the treatment of benign prostatic hyperplasia (BPH) and has remarkable curative effect.

AIM OF THE STUDY

To screen the potential 5-Lipoxygenase(5-LOX) inhibitors from ZSP extract.

MATERIALS AND METHODS

A new approach based on affinity ultrafiltration-ultra performance liquid chromatography-mass spectrometry(UPLC-MS) was established and validated. Zileuton and glipizide were chosen as positive and negative control drug, respectively. For better screening result, the concentration of 5-LOX enzyme, incubation temperature and time, pH and ion strength were optimized. In addition, 5-LOX inhibitory assay in vitro and molecular docking technique were used for further verification.

RESULTS

20 compounds were characterized in the ultrafiltrate by high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and 16 ligands showed binding ability to 5-LOX. Among them, six ligands were deduced as high-potential 5-LOX inhibitors with their high specific binding values (>2.0). The inhibitory activities of anemarrhenasaponin I, timosaponin AI, nyasol and demethyleneberberine were confirmed by the 5-LOX inhibitory assay for validating the reliability of affinity ultrafiltration approach and the computer-simulated molecular docking technique further clarified the possible mechanism of action between the active compounds and the 5-LOX active sites.

Palmatine: A review of pharmacological properties and pharmacokinetics

The aim of this review is to collect together the results of the numerous studies over the last two decades on the pharmacological properties of palmatine published in scientific databases like Scopus and PubMed, which are scattered across different publications. Palmatine, an isoquinoline alkaloid from the class of protoberberines, is a yellow compound present in the extracts from different representatives of Berberidaceae, Papaveraceae, Ranunculaceae, and Menispermaceae. It has been extensively used in traditional medicine of Asia in the treatment of jaundice, liver-related diseases, hypertension, inflammation, and dysentery. New findings describe its possible applications in the treatment of civilization diseases like central nervous system-related problems. This review intends to let this alkaloid come out from the shade of a more frequently described alkaloid: berberine. The toxicity, pharmacokinetics, and biological activities of this protoberberine alkaloid will be developed in this work.

Inhibitory and inductive effects of Corydalis saxicola Bunting total alkaloids (CSBTA) on cytochrome P450s in rats

Corydalis saxicola Bunting, a well-known traditional Chinese medicine in south China, has been widely used for the treatment of various hepatic diseases. Its active ingredients are Corydalis saxicola Bunting total alkaloids (CSBTA), which primarily include dehydrocavidine, palmatine, and berberine. These representative alkaloids could be metabolized by hepatic CYP450s. Hence, it is necessary to investigate the potential influences of CSBTA on CYP450s to explore the possibility of herb-drug interactions. In present study, in vitro inhibition and in vivo induction studies were performed to evaluate the potential effects of CSBTA extract on CYP450s in rats. Inhibition assay illustrated that CSBTA exerted inhibitory effects on CYP1A2 (IC₅₀ , 38.08 μg/ml; K_i , 14.3 μg/ml), CYP2D1 (IC₅₀ , 20.89 μg/ml; K_i , 9.34 μg/ml), CYP2C6/11 (IC₅₀ for diclofenac and S-mephenytoin, 56.98 and 31.59 μg/ml; K_i, 39.0 and 23.8 μg/ml), and CYP2B1 (IC₅₀ , 48.49 μg/ml; K_i , 36.3 μg/ml) in a noncompetitive manner. Induction study showed CSBTA had obvious inhibitory rather than inductive effects on CYP1A2 and CYP2C6/11. Interestingly, neither inhibition nor induction on CYP3A was observed for CSBTA. In conclusion, CSBTA-drug interactions might occur through CYP450s inhibition, particularly CYP1A and CYP2D. Further studies are still needed to elucidate the underlying mechanisms of inhibition.

Metabolic profile of Rhizoma coptidis in human plasma determined using ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry

RATIONALE

Rhizoma coptidis extract and its alkaloids show various pharmacological activities, but its metabolic profile in human plasma has not been thoroughly investigated. In the present research, the metabolism of Rhizoma coptidis at a clinical dose (5 g/60 kg/day) was systematically analyzed to determine its biotransformation processes in human plasma.

METHODS

In this research, the metabolites of Rhizoma coptidis in human plasma after oral administration of Rhizoma coptidis extract at a clinical dose were investigated using ultra-high-performance liquid chromatography (UHPLC) coupled with high-resolution LTQ-Orbitrap mass spectrometry. The structural elucidation of the constituents was confirmed by comparing their retention times (t_R ) and MSⁿ fragments with those of standards and literature reports.

RESULTS

In total, two prototypes and twelve metabolites were detected in human plasma. The two prototypes were confidently identified using reference standards. Of the compounds detected, M7 (berberrubinen-9-O-glucuronide) was the most abundant based on its peak area, which indicates that this compound might be a pharmacokinetic marker for Rhizoma coptidis alkaloids in humans. Based on the metabolites detected in human plasma, a possible metabolic pathway for Rhizoma coptidis in vivo was proposed.

CONCLUSIONS

The results indicated that the alkaloids in Rhizoma coptidis were extensively biotransformed in vivo mainly via conjugation with glucuronic acid (GluA) or sulfuric acid (SulA) to form phase II metabolites, and the GluA metabolites are likely the dominant form in human plasma. To the best of our knowledge, this is the first in vivo evaluation of the metabolic profile of the whole Rhizoma coptidis extract in human plasma, which is essential for determining the chemicals responsible for the pharmacological activities of Rhizoma coptidis in vivo. Moreover, it would be beneficial for us to further systematically study the pharmacokinetic behavior of Rhizoma coptidis in humans.

Identification of Metabolites of the Cardioprotective Alkaloid Dehydrocorydaline in Rat Plasma and Bile by Liquid Chromatography Coupled with Triple Quadrupole Linear Ion Trap Mass Spectrometry

Dehydrocorydaline (DHC), a quaternary alkaloid from Corydalis yanhusuo, has been demonstrated to be the active constituent in the treatment of coronary heart disease. In this study, a high-performance liquid chromatography–electrospray ionization–triple quadrupole linear ion trap mass spectrometry (HPLC–ESI–QTRAP MS) technique was used to identify DHC metabolites in plasma and bile after oral administration of DHC to rats. A total of 18 metabolites (M1 to M18) were identified and characterized by LC–MS/MS in the positive ion mode. These 18 metabolites were all present in rat bile, while only 9 were detected in plasma. O-demethylation, hydroxylation, di-hydroxylation, glucuronidation of O-demethyl DHC, sulfation of O-demethyl DHC and di-hydroxylation of dehydro-DHC were the major metabolic pathways of DHC. This is the first time that these metabolites of DHC have been identified in rat plasma and bile, which provides useful information for further analysis of the biotransformation of DHC and other quaternary protoberberine-type alkaloids.

Identification of metabolites of palmatine in rats after oral administration using ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Palmatine (PAL), a protopalmatine alkaloid, is an active constituent in a number of medicinal plants. In order to obtain a comprehensive and systematic metabolic profile of PAL, we investigated its metabolites in plasma, liver tissue, bile, urine, and feces samples after intragastrical administration to Sprague-Dawley rats with a dose of 100 mg/kg/day.

METHODS

In this study, a rapid and sensitive method by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC/QTOF-MS), and Metabolynx™ software with the mass defect filter (MDF) technique was developed for screening and identification of the metabolites. The structural elucidation of the metabolites was performed by comparing their molecular weights and fragment ions with those of the parent drug.

RESULTS

As a result, a total of 58 metabolites were identified in rat biological samples including 46 metabolites in urine, 18 metabolites in plasma, 34 metabolites in bile, 26 metabolites in liver tissue, and 10 metabolites in feces. Among them, six major metabolites were fully confirmed using reference standards and others were identified by retention time, accurate mass and fragment ions.

CONCLUSIONS

These results indicated that phase I reactions (demethylation and hydroxylation) and phase II reaction (glucuronidation and sulfation) were the main metabolic pathways of PAL in vivo. This research enhances our understanding of metabolism of PAL in rats, and provides useful information on the action mechanism of PAL. Copyright © 2017 John Wiley & Sons, Ltd.

Metabolic profiling of myrislignan by UPLC-ESI-QTOFMS-based metabolomics

The metabolic map of myrislignan was determined by UPLC-ESI-QTOFMS-based metabolomics in vivo and in vitro.