The Efflux Mechanism of Fraxetin-O-Glucuronides in UGT1A9-Transfected HeLa Cells: Identification of Multidrug Resistance-Associated Proteins 3 and 4 (MRP3/4) as the Important Contributors

Phenolic Biotransformations in Wheatgrass Juice after Primary and Secondary Fermentation

Fermented wheatgrass juice was prepared using a two-stage fermentation process by employing Saccharomyces cerevisiae and recombinant Pediococcus acidilactici BD16 (alaD⁺). During fermentation, a reddish-brown hue appeared in wheatgrass juice due to production of different types of red pigments. The fermented wheatgrass juice has considerably higher content of anthocyanins, total phenols and beta-carotenes as compared to unfermented wheatgrass juice. It has low ethanol content, which might be ascribed to the presence of certain phytolignans in wheatgrass juice. Several yeast-mediated phenolic transformations (such as bioconversion of coumaric acid, hydroxybenzoic acid, hydroxycinnamic acid and quinic acid into respective derivatives; glycosylation and prenylation of flavonoids; glycosylation of lignans; sulphonation of phenols; synthesis of carotenoids, diarylnonanoids, flavanones, stilbenes, steroids, quinolones, di- and tri-terpenoids and tannin) were identified in fermented wheatgrass juice using an untargeted liquid chromatography (LC)-mass spectrometry (MS)-matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF)/time-of-flight (TOF) technique. The recombinant P. acidilactici BD16 (alaD⁺) also supported flavonoid and lignin glycosylation; benzoic acid, hydroxycoumaric acid and quinic acid derivatization; and synthesis of anthraquinones, sterols and triterpenes with therapeutic benefits. The information presented in this manuscript may be utilized to elucidate the importance of Saccharomyces cerevisiae and P. acidilactici BD16 (alaD⁺) mediated phenolic biotransformations in developing functional food supplements such as fermented wheatgrass juice.

Inhibition of estrogen sulfation by Xian-Ling-Gu-Bao capsule

Xian-Ling-Gu-Bao capsule (XLGB) is a widely prescribed traditional Chinese medicine used for the treatment of osteoporosis. However, it significantly elevates levels of serum estrogens. Here we aimed to assess the dominant contributors of sulfotransferase (SULT) enzymes to the sulfation of estrogens and identify the effective inhibitors of this pathway in XLGB. First, estrone, 17β-estradiol, and estriol underwent sulfation in human liver S9 extracts. Phenotyping reactions and enzyme kinetics assays revealed that SULT1A1, 1A2, 1A3, 1C4, 1E1, and 2A1 all participated in estrogen sulfation, with SULT1E1 and 1A1 as the most important contributors. The incubation system for these two active enzymes were optimized with Tris-HCl buffer, DL-Dithiothreitol (DTT), MgCl₂, adenosine 3'-phosphate 5'-phosphosulfate (PAPS), protein concentration, and incubation time. Then, 29 compounds in XLGB were selected to investigate their inhibitory effects and mechanisms against SULT1E1 and 1A1 through kinetic modelling. Moreover, in silico molecular docking was used to validate the obtained results. And finally, the prenylated flavonoids (isobavachin, neobavaisoflavone, etc.) from Psoralea corylifolia L., prenylated flavanols (icariside II) from Epimedium brevicornu Maxim., tanshinones (dihydrotanshinone, tanshinone II-A,) from Salvia miltiorrhiza Bge., and others (corylifol A, corylin) were identified as the most potent inhibitors of estrogen sulfation. Taken together, these findings provide insights into the understanding regioselectivity of estrogen sulfation and identify the effective components of XLGB responsible for the promotion of estrogen levels.

Fraxetin attenuates disrupted behavioral and central neurochemical activity in a model of chronic unpredictable stress

Purpose: Chronic unpredictable stress (CUS) induces long-term neuronal and synaptic plasticity with a neurohormonal disbalance leading to the development of co-existing anxiety, depression, and cognitive decline. The side effects and delayed onset of current clinically used antidepressants has prompted a quest for antidepressants with minimum drawbacks. Fraxetin is a natural coumarin derivative with documented antioxidant and neuroprotective activity though its effects on stress are unknown. This study therefore aimed to investigate any possible acute effect of fraxetin in behavioral tests including a CUS paradigm in correlation with brain regional neurochemical changes. Methods: Mice were subjected to a series of mild stressors for 14 days to induce CUS. Furthermore, behavioral performance in the open field test, forced swim test (FST), Y-maze and elevated plus-maze were evaluated. Postmortem frontal cortical, hippocampal and striatal tissues were analyzed via high-performance liquid chromatography (HPLC) for neurochemical changes. Result: Acute administration of fraxetin (20-60 mg/kg, orally) decreased depression-like behavior in the FST and behavioral anxiety in both the open field test and elevated plus-maze. Memory deficits induced during the CUS paradigm were markedly improved as reflected by enhanced Y maze performance. Concurrent biochemical and neurochemical analyses revealed that only the two higher fraxetin doses decreased elevated serum corticosterone levels while diminished serotonin levels in the frontal cortex, striatum and hippocampus were reversed, though noradrenaline was only raised in the striatum. Concomitantly, dopamine levels were restored by fraxetin at the highest dose exclusively in the frontal cortex. Conclusion: Acute treatment with fraxetin attenuated CUS-induced behavioral deficits, ameliorated the increased corticosterone level and restored altered regional neurotransmitter levels and this may indicate a potential application of fraxetin in the management of anxiety and depression modeled by CUS. However, further studies are warranted regarding the chronic effects of fraxetin behaviorally and neurochemically.

Metabolic and pharmacological profiling of Penicillium claviforme by a combination of experimental and bioinformatic approaches

BACKGROUND

Penicillium produces a wide range of structurally diverse metabolites with significant pharmacological impacts in medicine and agriculture. For the first time, a complete metabolome of Penicillium claviforme (P. claviforme) (FBP-DNA-1205) was studied alongside pharmacological research in this study.

METHODS

The metabolic profile of P. claviforme fermented on Potato Dextrose Broth (PDB) was investigated in this work. The complete metabolomics studies of fungus were performed using GC-MS and LC-MS-QTOF techniques. An in vitro model was utilised to study the cytotoxic and antioxidant activities, while an in vivo model was employed to investigate the antinociceptive and acute toxicity activities. Molecular Operating Environment (MOE) software was used for molecular docking analysis.

RESULTS

GC-MS study showed the presence of alkanes, fatty acids, esters, azo and alcoholic compounds. Maculosin, obtain, phalluside, quinoline, 4,4'-diaminostilbene, funaltrexamine, amobarbital, and fraxetin were among the secondary metabolites identified using the LC-MS-QTOF technique. The n-hexane fraction of P. claviforme displayed significant cytotoxic activity in vitro, with an LD50 value of 92.22 µgml^-1. The antinociceptive effects in vivo were dose-dependent significantly (p < .001). Interestingly, during the 72 h of investigation, no acute toxicity was demonstrated. In addition, a docking study of tentatively identified metabolites against the inflammatory enzyme (COX-2) supported the antinociceptive effect in an in silico model.

CONCLUSION

Metabolic profile of P. claviforme shows the presence of biologically relevant compounds in ethyl acetate extract. In addition, P. claviforme exhibits substantial antioxidant and cytotoxic activities in an in vitro model as well as antinociceptive activity in an in vivo model. The antinociceptive action is also supported by a molecular docking study. This research has opened up new possibilities in the disciplines of mycology, agriculture, and pharmaceutics. Key messagesThe first time explored complete metabolome through GC-MS and LC-MS-QTOF.Both in vivo & in vitro pharmacological investigation of P. claviforme.In silico molecular docking of LC-MS-QTOF metabolites.

Potential Determinants for Metabolic Fates and Inhibitory Effects of Isobavachalcone Involving in Human Cytochrome P450, UDP-Glucuronosyltransferase Enzymes, and Efflux Transporters

Isobavachalcone, a naturally occurring chalcone in Psoralea corylifolia, posses many biological properties including anticancer, antiplatelet, and antifungal. However, its glucuronidation, glucuronides excretion, and drug-drug interaction (DDI) involving in human cytochrome P450 (CYP), UDP-glucuronosyltransferase (UGT) enzymes, and efflux transporters (BCRP and MRPs) remains unclear so far. After incubation, three glucuronides were produced by HLM and HIM with total intrinsic clearance (CL_int) of 236.71 and 323.40 μL/min/mg, respectively. Reaction phenotyping proved UGT1A1, 1A3, 1A7, 1A8, and 1A9 played important roles in glucuronidation with total CL_int values of 62.69-143.00 μL/min/mg. Activity correlation analysis indicated UGT1A1 and UGT1A3 participated more in the glucuronidation. In addition, the glucuronidation showed marked species differences, and rabbits and dogs were probably appropriate model animals to investigate the in vivo glucuronidation. Furthermore, BCRP, MRP1, and MRP4 transporters were identified as the most important contributors to glucuronides excretion in HeLa1A1 cells based on gene silencing method. Moreover, isobavachalcone demonstrated broad-spectrum inhibitory effects against CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, UGT1A1, UGT1A9, UGT2B7 with IC₅₀ values of 1.08-9.78 μM. Except CYP2B6 and CYP2D6, the calculated [I]/K_i values for other enzymes were all greater than 0.1, indicating the inhibition of systemic metabolism or elimination for these enzyme substrates seems likely. Taken together, we summarized metabolic fates of isobavachalcone including glucuronidation and efflux transport as well as inhibitory effects involving in human CYP and UGT enzymes.

Multidrug resistance proteins (MRPs): Structure, function and the overcoming of cancer multidrug resistance

ATP-binding cassette (ABC) transporters mediate the ATP-driven translocation of structurally and mechanistically distinct substrates against steep concentration gradients. Among the seven human ABC subfamilies namely ABCA-ABCG, ABCC is the largest subfamily with 13 members. In this respect, 9 of the ABCC members are termed "multidrug resistance proteins" (MRPs1-9) due to their ability to mediate cancer multidrug resistance (MDR) by extruding various chemotherapeutic agents or their metabolites from tumor cells. Furthermore, MRPs are also responsible for the ATP-driven efflux of physiologically important organic anions such as leukotriene C₄, folic acid, bile acids and cAMP. Thus, MRPs are involved in important regulatory pathways. Blocking the anticancer drug efflux function of MRPs has shown promising results in overcoming cancer MDR. As a result, many novel MRP modulators have been developed in the past decade. In the current review, we summarize the structure, tissue distribution, biological and pharmacological functions as well as clinical insights of MRPs. Furthermore, recent updates in MRP modulators and their therapeutic applications in clinical trials are also discussed.

Potential metabolism determinants and drug-drug interactions of a natural flavanone bavachinin

Bavachinin, a natural bioactive flavanone, is reported to have many pharmacological proprieties, especially anti-osteoporosis activity. Here we aim to determine the roles of cytochrome P450s (CYP), UDP-glucuronosyltransferases (UGT), and efflux transporters in metabolism and drug–drug interactions (DDI) of bavachinin. Phase I metabolism and glucuronidation were performed by human liver microsomes (HLM) and human intestine microsomes (HIM). Reaction phenotyping was used to identify the main CYPs and UGTs. Gene silencing methods were employed to investigate the roles of breast cancer resistance protein (BCRP) and multidrug resistance-associated proteins (MRPs) in HeLa1A1 cells. Inhibition mechanisms towards CYPs and UGTs were explored through kinetic modeling. Three phase I metabolites (M1–M3) and one glucuronide (G1) were detected after incubation of bavachinin with HLM and HIM. The intrinsic clearance (CL_int) values of M1 and G1 by HLM were 89.4 and 270.2 μL min⁻¹ mg⁻¹, respectively, while those of M3 and G1 by HIM were 25.8 and 247.1 μL min⁻¹ mg⁻¹, respectively. CYP1A1, 1A2, 1B1, 2C8, 2C19, and UGT1A1, 1A8 participated more in bavachinin metabolism. The metabolism showed marked species difference. BCRP and MRP4 were identified as the main contributors. Bavachinin displayed potent inhibitory effects against several CYP and UGT isozymes (K_i = 0.28–2.53 μM). Bavachinin was subjected to undergo metabolism and disposition by CYPs, UGTs, BCRP, MRP4, and was also a potent non-selective inhibitor against several CYPs and UGTs.

Metabolism, efflux transport and drug–drug interactions of bavachinin.

Characterization of metabolic activity, isozyme contribution and species differences of bavachin, and identification of efflux transporters for bavachin-O-glucuronide in HeLa1A1 cells

Objectives

Bavachin is a bioactive natural flavonoid with oestrogen-like activity. Here, we aimed to investigate its metabolic and disposal fates involving in CYPs, UGTs and efflux transporters.

Methods

Phase I metabolism and glucuronidation were performed by human liver microsomes (HLM). Reaction phenotyping and activity correlation analysis were performed to identify the main CYP and UGT isozymes. Chemical inhibition and gene knock-down approaches were employed to explore the function of BCRP and MRPs.

Key findings

Five phase I metabolites (M1–M5) and three glucuronides (G1–G3) were identified. The CLint values for M4 and G1 by HLM were 127.99 and 1159.07 μl/min per mg, respectively. Reaction phenotyping results suggested CYP1A1 (208.85 μl/min per mg) and CYP2C9 (107.51 μl/min per mg), and UGT1A1 (697.19 μl/min per mg), UGT1A7 (535.78 μl/min per mg), UGT1A8 (247.72 μl/min per mg) and UGT1A9 (783.68 μl/min per mg) all participated in the metabolism of bavachin. In addition, activity correlation analysis also supported the results above. Furthermore, the metabolism exhibited marked species differences, and rabbits were the appropriate model animals. Moreover, MRP4 was identified as the main contributor based on chemical inhibition and gene silencing approaches.

Conclusions

CYP1A1 and CYP2C9, UGT1A1, UGT1A7, UGT1A8 and UGT1A9, and MRP4 all played important roles in the metabolism and disposition of bavachin.

Fraxetin inhibits the growth of colon adenocarcinoma cells via the Janus kinase 2/signal transducer and activator of transcription 3 signalling pathway

OBJECTIVE

Fraxetin, extracted from the bark of Fraxinus rhynchophylla, has been shown to exhibit antitumour and anti-inflammatory pharmacological properties. However, the mechanism underlying its anticancer activity towards colon adenocarcinoma (COAD) is not well understood. We aimed to determine the antitumour effect of fraxetin on COAD cell lines and elucidate its biochemical and molecular targets.

METHODS

The cell lines HCT116 and DLD-1 were used to evaluate the in vitro antitumour efficacy of fraxetin. Cytotoxicity and viability were assessed by CCK-8 and plate colony formation assays. Flow cytometry was used to assess apoptosis and cell cycle progression in fraxetin-treated COAD cells. Western blot, RT-qPCR, molecular docking, immunohistochemical, and immunofluorescence analyses were used to gain insights into cellular and molecular mechanisms. Preclinical curative effects were evaluated in nude mouse xenograft models.

RESULTS

Fraxetin significantly inhibited COAD cell proliferation in both dose- and time-dependent manners, specifically by inducing S-phase cell cycle arrest and triggering intrinsic apoptosis. Additionally, the level of p-JAK2 was decreased by fraxetin via the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signalling pathway. Interestingly, in COAD cells, fraxetin directly targeted the Y¹⁰⁰⁷ and Y¹⁰⁰⁸ residues of JAK2 to suppress its auto- or transphosphorylation, leading to decreased activation of its downstream effector STAT3 and blocking its nuclear translocation. Finally, fraxetin exhibited good tumour growth suppression activity and low toxicity.

CONCLUSIONS

Fraxetin inhibits the proliferation of COAD cells by regulating the JAK2/STAT3 signalling pathway, providing evidence that targeting JAK2 with fraxetin may offer a novel potential auxiliary therapy for COAD treatment.

Metabolism and disposition of corylifol A from Psoralea corylifolia: metabolite mapping, isozyme contribution, species differences and identification of efflux transporters for corylifol A-O-glucuronide in HeLa1A1 cells

Corylifol A (CA), a phenolic compound from Psoralea corylifolia, possessed several biological properties but poor bioavailability. Here we aimed to investigate the roles of cytochromes P450s (CYPs), UDP-glucuronosyltransferases (UGTs) and efflux transporters in metabolism and disposition of CA.Metabolism of CA was evaluated in HLM, expressed CYPs and UGTs. Chemical inhibitors and shRNA-mediated gene silencing of multidrug resistance-associated proteins (MRPs) and breast cancer resistance protein (BCRP) were performed to assess the roles of transporters in CA disposition.Three oxidated metabolites (M1-M3) and two glucuronides (M4-M5) were detected. The intrinsic clearances (CL_int) values of M1 and M4 in HLM were 48.10 and 184.03 μL/min/mg, respectively. Additionally, CYP1A1, 2C8 and 2C19 were identified as main contributors with CL_int values of 13.01-49.36 μL/min/mg, while UGT1A1, 1A7, 1A8 and 1A9 were with CL_int values ranging from 85.01 to 284.07 μL/min/mg. Furthermore, activity correlation analysis proved CYP2C8, UGT1A1 and 1A9 were the main active hepatic isozymes. Besides, rats and monkeys were appropriate model animals. Moreover, dipyridamole and MK571 both could significantly inhibit M4 efflux. Gene silencing results also indicated MRP4 and BCRP were major contributors in HeLa1A1 cells.Taken together, CYPs, UGTs, MRP4 and BCRP were important determinants of CA pharmacokinetics.

An investigation of the metabolic activity, isozyme contribution, species differences and potential drug–drug interactions of PI-103, and the identification of efflux transporters for PI-103-O-glucuronide in HeLa1A9 cells

PI-103 is a phosphatidylinositol 3-kinase inhibitor that includes multiple receptor affinity modifications, and it is also a therapeutic drug candidate primarily for human malignant tumors. However, its metabolic fate and potential drug–drug interactions involving human cytochrome P450 (CYP) and UDP-glucuronosyltransferases (UGT) enzymes remain unknown. In this study, our results demonstrated that the intrinsic clearance (CL_int) values of oxidated metabolite (M1) in human liver microsomes (HLM) and human intestine microsomes (HIM) were 3.10 and 0.08 μL min⁻¹ mg⁻¹, respectively, while PI-103 underwent efficient glucuronidation with CL_int values of 15.59 and 211.04 μL min⁻¹ mg⁻¹ for mono-glucuronide (M2) by HLM and HIM, respectively. Additionally, reaction phenotyping results indicated that CYP1A1 (51.50 μL min⁻¹ mg⁻¹), 1A2 (46.96 μL min⁻¹ mg⁻¹), and UGT1A1 (18.80 μL min⁻¹ mg⁻¹), 1A7 (8.52 μL min⁻¹ mg⁻¹), 1A8 (8.38 μL min⁻¹ mg⁻¹), 1A9 (34.62 μL min⁻¹ mg⁻¹), 1A10 (107.01 μL min⁻¹ mg⁻¹) were the most important contributors for the oxidation and glucuronidation of PI-103. Chemical inhibition assays also suggest that CYP1A2 and UGT1A1, 1A9 play a predominant role in the metabolism of PI-103 in HLM. Significant activity correlations were detected between phenacetin-N-deacetylation and M1 (r = 0.760, p = 0.004) as well as β-estradiol-3-O-glucuronide and M2 (r = 0.589, p = 0.044), and propofol-O-glucuronidation and M2 (r = 0.717, p = 0.009). Furthermore, the metabolism of PI-103 revealed marked species differences, and dogs, rats, mice and mini-pigs were not the appropriate animal models. Gene silencing of breast cancer resistance protein (BCRP) or multidrug resistance-associated protein (MRPs) transporter results indicated that M2 was mainly excreted by BCRP, MRP1 and MRP4 transporters. Moreover, PI-103 displayed broad-spectrum inhibition towards human CYPs and UGTs isozymes with IC₅₀ values ranging from 0.33 to 6.89 μM. Among them, PI-103 showed potent non-competitive inhibitory effects against CYP1A2, 2C19, 2E1 with IC₅₀ and K_i values of less than 1 μM. In addition, PI-103 exhibited moderate non-competitive inhibition against UGT1A7, 2B7, and moderate mixed-type inhibition towards CYP2B6, 2C9 and UGT1A3. Their IC₅₀ and K_i values were 1.16–6.89 and 0.56–5.64 μM, respectively. In contrast, PI-103 could activate the activity of UGT1A4 in a mechanistic two-site model with a K_i value of 13.76 μM. Taken together, PI-103 was subjected to significant hepatic and intestinal metabolism. CYP1A1, 1A2 and UGT1A1, 1A7, 1A8, 1A9, 1A10 were the main contributing isozymes, whereas BCRP, MRP1 and MRP4 contributed most to the efflux excretion of M2. Meanwhile, PI-103 had a potent and broad-spectrum inhibitory effect against human CYPs and UGTs isozymes. These findings could improve understanding of the metabolic fates and efflux transport of PI-103. The inhibited human CYP and UGT activities could trigger harmful DDIs when PI-103 is co-administered with clinical drugs primarily cleared by these CYPs or UGTs isoforms. Additional in vivo studies are required to evaluate the clinical significance of the data presented herein.

Metabolic activity and disposition characteristics of PI-103.