The Human UDP-glucuronosyltransferase UGT2A1 and UGT2A2 enzymes are highly active in bile acid glucuronidation

Nrf-2/HO-1 activation protects against oxidative stress and inflammation induced by metal welding fume UFPs in 16HBE cells

As one of the main occupational hazards, welding fumes can cause oxidative damage and induce series of diseases, such as COPD or asthma. To clarify the effects of the metal fume ultrafine particulates (MF-UFPs) of welding fumes on oxidative damage, UFPs were collected by melt inert gas (MIG) and manual metal arc (MMA) welding, and the composition was confirmed. Human bronchial epithelial 16HBE cells were treated with 0-1000 µg/cm2 MF-UFPs to analyse the cytotoxicity, oxidative stress and cytokines. The protein and mRNA expression of Keap1-Nrf-2/antioxidant response elements (AREs) signalling pathway components were also analysed. After 4 h of treatment, the cell viability decreased 25% after 33.85 and 32.81 µg/cm2 MIG/MMA-UFPs treated. The intracellular ATP concentrations were also decreased significantly, while LDH leakage was increased. The decreased mitochondrial membrane potential and increased ROS suggested the occurrence of oxidative damage, and the results of proteome profiling arrays also showed a significant increase in IL-6 and IL-8. The expression of AREs which related to antioxidant and anti-inflammatory were also increased. These results indicate that the MF-UFPs can cause oxidative stress in 16HBE cells and activate the Nrf-2/ARE signalling pathway to against oxidative damage.

PPAR-Mediated Bile Acid Glucuronidation: Therapeutic Targets for the Treatment of Cholestatic Liver Diseases

Cholestatic liver diseases, including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), result from an impairment of bile flow that leads to the hepatic retention of bile acids, causing liver injury. Until recently, the only approved treatments for PBC were ursodeoxycholic acid (UDCA) and obeticholic acid (OCA). While these therapies slow the progression of PBC in the early stage of the disease, approximately 40% of patients respond incompletely to UDCA, and advanced cases do not respond. UDCA does not improve survival in patients with PSC, and patients often have dose-limiting pruritus reactions to OCA. Left untreated, these diseases can progress to fibrosis and cirrhosis, resulting in liver failure and the need for transplantation. These shortcomings emphasize the urgent need for alternative treatment strategies. Recently, nuclear hormone receptors have been explored as pharmacological targets for adjunct therapy because they regulate enzymes involved in bile acid metabolism and detoxification. In particular, the peroxisome proliferator-activated receptor (PPAR) has emerged as a therapeutic target for patients with PBC or PSC who experience an incomplete response to UDCA. PPARα is predominantly expressed in the liver, and it plays an essential role in the regulation of cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT) enzymes, both of which are critical enzyme families involved in the regulation of bile acid metabolism and glucuronidation, respectively. Importantly, PPARα agonists, e.g., fenofibrate, have shown therapeutic benefits in reducing elevated markers of cholestasis in patients with PBC and PSC, and elafibranor, the first PPAR (dual α, β/δ) agonist, has been FDA-approved for the second-line treatment of PBC. Additionally, newer PPAR agonists that target various PPAR isoforms (β/δ, γ) are under development as an adjunct therapy for PBC or PSC, although their impact on glucuronidation pathways are less characterized. This review will focus on PPAR-mediated bile acid glucuronidation as a therapeutic pathway to improve outcomes for patients with PBC and PSC.

Transcriptomic Association Analysis of the Metabolic Mechanism of Sulfamethoxazole in Channel Catfish (Ictalurus punctatus)

Sulfamethoxazole is a widely used antimicrobial drug used to treat bacterial diseases in aquaculture. To understand the gene expression in channel catfish liver after treatment with sulfamethoxazole, in this study, the treatment group received sulfamethoxazole (100 mg/kg bw), which was administered orally once, and samples were taken at 5 h, 12 h, and 6 d after the administration of sulfamethoxazole, while the control group was orally administered sterile water. To further identify potentially significant genes, a transcriptome analysis using RNA-seq was carried out. More than 50 million high-quality reads were found. After filtering and quality analysis, these reads were identified as 54,169,682, 51,313,865, 51,608,845, and 49,333,491. After counting 23,707 of these transcripts for gene expression, it was discovered that 14,732 of them had genes with differential expression. Moreover, we found that the annotation with the most GO variation was "cellular process" (1616 genes), "metabolic process" (1268 genes), "binding" (1889 genes), and "catalytic activity" (1129 genes). KEGG pathways showed that the "metabolic pathway" was the pathway that was significantly enriched in both experimental groups when comparing the experimental groups: 5 h and 12 h (128 genes); 5 h and 6 d (332 genes); and 12 h and 6 d (348 genes). Also, UDP- glucuronosyltransferase (ugt), which is associated with glucuronidation, and UDP-glucuronosyltransferase 2C1-like (ugt2a1) showed significant upregulation. Carboxylesterase 5A-like (ces3), which promotes fatty acyl and cholesteryl ester metabolism, and the glutathione transferase family were upregulated in the expression of sulfamethoxazole metabolism in the liver, which significantly affected the metabolic effects of the drug. Meanwhile, dypd, uck2b, and rrm2, which are related to nucleotide synthesis and metabolism, were upregulated. Our study extends the knowledge of gene expression in drug metabolism in channel catfish and further provides insight into the molecular mechanism of sulfamethoxazole metabolism.

Acute and subacute hepatotoxicity of genipin in mice and its potential mechanism

Gardenia, as a medicinal and edible herb, has the pharmacological activity of protecting the liver and cholagogue, but the hepatotoxicity induced by the chemical component genipin (GP) limits its application. The aim of this study was to evaluate the acute and subacute hepatotoxicity of genipin in normal mice and mice with α-naphthalene isothiocyanate (ANIT)-induced liver injury. The results of the acute study showed that the LD50 of genipin was 510 mg/kg. Genipin exhibited hepatotoxicity in normal and jaundiced mice at doses of 125 mg/kg, 250 mg/kg, and 500 mg/kg, which increased with dose. In a 28-day subacute study, the 50 mg/kg and 100 mg/kg dose groups showed some pharmacodynamic effects at 7 days but exhibited hepatotoxicity that increased with time and improved after drug withdrawal. In addition, based on proteomics, the mechanism of liver injury induced by genipin may be related to the disruption of the UDP-glucuronosyltransferase system and cytochrome P450 enzyme activity. In conclusion, this study showed that genipin hepatotoxicity was time- and dose dependent, but it is worth mentioning that hepatotoxicity was reversible. It is hoped that this study will provide a scientific basis for circumventing the adverse effects of genipin.

Novel insights into bile acid detoxification via CYP, UGT and SULT enzymes

Bile acid (BA) homeostasis is a complex and precisely regulated process to prevent impaired BA flow and the development of cholestasis. Several reactions, namely hydroxylation, glucuronidation and sulfation are involved in BA detoxification. In the present study, we employed a comprehensive approach to identify the key enzymes involved in BA metabolism using human recombinant enzymes, human liver microsomes (HLM) and human liver cytosol (HLC). We showed that CYP3A4 was a crucial step for the metabolism of several BAs and their taurine and glycine conjugated forms and quantitatively described their metabolites. Glucuronidation and sulfation were also identified as important drivers of the BA detoxification process in humans. Moreover, lithocholic acid (LCA), the most hydrophobic BA with the highest toxicity potential, was a substrate for all investigated processes, demonstrating the importance of hepatic metabolism for its clearance. Collectively, this study identified CYP3A4, UGT1A3, UGT2B7 and SULT2A1 as the major contributing (metabolic) processes in the BA detoxification network. Inhibition of these enzymes by drug candidates is therefore considered as a critical mechanism in the manifestation of drug-induced cholestasis in humans and should be addressed during the pre-clinical development.

The chromosome-level genome and key genes associated with mud-dwelling behavior and adaptations of hypoxia and noxious environments in loach (Misgurnus anguillicaudatus)

BACKGROUND

The loach (Misgurnus anguillicaudatus), the most widely distributed species of the family Cobitidae, displays a mud-dwelling behavior and intestinal air-breathing, inhabiting the muddy bottom of extensive freshwater habitats. However, lack of high-quality reference genome seriously limits the interpretation of the genetic basis of specialized adaptations of the loach to the adverse environments including but not limited to the extreme water temperature, hypoxic and noxious mud environment.

RESULTS

This study generated a 1.10-Gb high-quality, chromosome-anchored genome assembly, with a contig N50 of 3.83 Mb. Multiple comparative genomic analyses found that proto-oncogene c-Fos (fos), a regulator of bone development, is positively selected in loach. Knockout of fos (ID: Mis0086400.1) led to severe osteopetrosis and movement difficulties, combined with the comparison results of bone mineral density, supporting the hypothesis that fos is associated with loach mud-dwelling behavior. Based on genomic and transcriptomic analysis, we identified two key elements involved in the intestinal air-breathing of loach: a novel gene (ID: mis0158000.1) and heat shock protein beta-1 (hspb1). The flavin-containing monooxygenase 5 (fmo5) genes, central to xenobiotic metabolism, undergone expansion in loach and were identified as differentially expressed genes in a drug stress trial. A fmo5-/- (ID: Mis0185930.1) loach displayed liver and intestine injury, indicating the importance of this gene to the adaptation of the loach to the noxious mud.

CONCLUSIONS

Our work provides valuable insights into the genetic basis of biological adaptation to adverse environments.

Exploring miRNA-mRNA regulatory modules responding to tannic acid stress in Micromelalopha troglodyta (Graeser) (Lepidoptera: Notodontidae) via small RNA sequencing

MicroRNAs (miRNAs) are small noncoding RNAs (sRNAs) that regulate gene expression by inhibiting translation or degrading mRNA. Although the functions of miRNAs in many biological processes have been reported, there is currently no research on the possible roles of miRNAs in Micromelalopha troglodyta (Graeser) involved in the response of plant allelochemicals. In this article, six sRNA libraries (three treated with tanic acid and three control) from M. troglodyta were constructed using Illumina sequencing. From the results, 312 known and 43 novel miRNAs were differentially expressed. Notably, some of the most abundant miRNAs, such as miR-432, miR-541-3p, and miR-4448, involved in important physiological processes were also identified. To better understand the function of the targeted genes, we performed Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The results indicated that differentially expressed miRNA targets were involved in metabolism, development, hormone biosynthesis, and immunity. Finally, we visualized a miRNA-mRNA regulatory module that supports the role of miRNAs in host-allelochemical interactions. To our knowledge, this is the first report on miRNAs responding to tannic acid in M. troglodyta. This study provides indispensable information for understanding the potential roles of miRNAs in M. troglodyta and the applications of these miRNAs in M. troglodyta management.

The Uridine diphosphate (UDP)-glycosyltransferases (UGTs) superfamily: the role in tumor cell metabolism

UDP-glycosyltransferases (UGTs), important enzymes in biotransformation, control the levels and distribution of numerous endogenous signaling molecules and the metabolism of a wide range of endogenous and exogenous chemicals. The UGT superfamily in mammals consists of the UGT1, UGT2, UGT3, and UGT8 families. UGTs are rate-limiting enzymes in the glucuronate pathway, and in tumors, they are either overexpressed or underexpressed. Alterations in their metabolism can affect gluconeogenesis and lipid metabolism pathways, leading to alterations in tumor cell metabolism, which affect cancer development and prognosis. Glucuronidation is the most common mammalian conjugation pathway. Most of its reactions are mainly catalyzed by UGT1A, UGT2A and UGT2B. The body excretes UGT-bound small lipophilic molecules through the bile, urine, or feces. UGTs conjugate a variety of tiny lipophilic molecules to sugars, such as galactose, xylose, acetylglucosamine, glucuronic acid, and glucose, thereby inactivating and making water-soluble substrates, such as carcinogens, medicines, steroids, lipids, fatty acids, and bile acids. This review summarizes the roles of members of the four UGT enzyme families in tumor function, metabolism, and multiple regulatory mechanisms, and its Inhibitors and inducers. The function of UGTs in lipid metabolism, drug metabolism, and hormone metabolism in tumor cells are among the most important topics covered.

Hepatitis C Virus Infection Upregulates Plasma Phosphosphingolipids and Endocannabinoids and Downregulates Lysophosphoinositols

A mass spectrometry-based lipidomic investigation of 30 patients with chronic hepatitis C virus (HCV) infection and 30 age- and sex-matched healthy blood donor controls was undertaken. The clustering and complete separation of these two groups was found by both unsupervised and supervised multivariate data analyses. Three patients who had spontaneously cleared the virus and three who were successfully treated with direct-acting antiviral drugs remained within the HCV-positive metabotype, suggesting that the metabolic effects of HCV may be longer-lived. We identified 21 metabolites that were upregulated in plasma and 34 that were downregulated (p < 1 × 10^-16 to 0.0002). Eleven members of the endocannabinoidome were elevated, including anandamide and eight fatty acid amides (FAAs). These likely activated the cannabinoid receptor GPR55, which is a pivotal host factor for HCV replication. FAAH1, which catabolizes FAAs, reduced mRNA expression. Four phosphosphingolipids, d16:1, d18:1, d19:1 sphingosine 1-phosphate, and d18:0 sphinganine 1-phosphate, were increased, together with the mRNA expression for their synthetic enzyme SPHK1. Among the most profoundly downregulated plasma lipids were several lysophosphatidylinositols (LPIs) from 3- to 3000-fold. LPIs are required for the synthesis of phosphatidylinositol 4-phosphate (PI4P) pools that are required for HCV replication, and LPIs can also activate the GPR55 receptor. Our plasma lipidomic findings shed new light on the pathobiology of HCV infection and show that a subset of bioactive lipids that may contribute to liver pathology is altered by HCV infection.

Association of gallstone and polymorphisms of UGT1A1*27 and UGT1A1*28 in patients with hepatitis B virus-related liver failure

Genetic variation in UDP-glucuronosyltransferase 1A1 gene (UGT1A1) is a lithogenic risk factor for gallstone formation. This study aimed to assess genotype and allele frequencies of common UGT1A1 variants in patients with gallstone and hepatitis B virus (HBV)-related hepatic failure. This study enrolled 113 healthy individuals (CTRL), 54 patients with HBV infection (HBV), 134 patients with gallstone-free hepatic failure and HBV infection, and 34 patients with gallstone-related hepatic failure and HBV infection (GRHF). Peripheral venous blood samples were collected for genomic DNA isolation. Polymerase chain reaction amplification was carried out for UGT1A1, followed by direct sequencing. Analysis for genotype and allele frequencies of UGT1A1 variants (UGT1A1*6, UGT1A1*27, UGT1A1*28, and UGT1A1*60) was performed. The allele distributions of the four groups did not deviate from Hardy–Weinberg equilibrium. Allele (A) and genotype (CA) frequency distributions of UGT1A1*27 were significantly different between GRHF and CTRL, or between GRHF and HBV. GRHF and CTRL exhibited significant differences in allele (A) and genotype (CA) frequency distributions of UGT1A1*28. Linkage disequilibrium analysis suggested that haplotype G-G-[TA]7-T may be associated with gallstone in HBV-related hepatic failure. Our data reveal that UGT1A1*27 and UGT1A1*28 variants are significantly observed in patients with GRHF compared to healthy individuals.

Genetic associations with lymphomas in Polish patients: A pooled-DNA genome-wide association analysis

Several single nucleotide polymorphisms (SNPs) associated with susceptibility to Hodgkin lymphoma (HL) and diffuse large B-cell lymphoma (DLBCL) have been identified. The aim of this study was to identify susceptibility loci for HL and DLBCL in Polish patients. Altogether, DLBCL (n = 218 and HL patients (n = 224) and healthy individuals (n = 1181) were recruited. Lymphoma diagnosis was based on standard criteria. Genome-wide association study (GWAS) was performed using pooled-DNA samples on llumina Infinium Omni2.5 Exome-8 v1.3, and selected loci were replicated by TaqMan SNP genotyping of individuals. GWAS detected thirteen and seven SNPs associated with DLBCL and HL, respectively. In the replication study, six and seven SNPs reached significance after correction for multiple testing in the DLBCL and HL cohorts, respectively. One and four SNPs associated with DLBCL and HL, respectively, were localized within, and two SNPs-near the major histocompatibility complex (MHC) region. In conclusion, the majority of loci associated with HL and DLBCL aetiology in previous studies have potential roles in immune function. Our pooled-DNA GWAS enabled the identification of several susceptibility loci for DLBCL and HL in the Polish population; some of them were mapped within or adjacent to the MHC, and other associated SNPs were located outside the MHC.

Dietary Macroalgae Saccharina japonica Ameliorates Liver Injury Induced by a High-Carbohydrate Diet in Swamp Eel (Monopterus albus)

A high-carbohydrate diet lowers the rearing cost and decreases the ammonia emission into the environment, whereas it can induce liver injury, which can reduce harvest yields and generate economic losses in reared fish species. Macroalgae Saccharina japonica (SJ) has been reported to improve anti-diabetic, but the protective mechanism of dietary SJ against liver injury in fish fed a high-carbohydrate diet has not been studied. Therefore, a 56-day nutritional trial was designed for swamp eel Monopterus albus, which was fed with the normal diet [20% carbohydrate, normal carbohydrate (NC)], a high carbohydrate diet (32% carbohydrate, HC), and a HC diet supplemented with 2.5% SJ (HC-S). The HC diet promoted growth and lowered feed coefficient (FC), whereas it increased hepatosomatic index (HSI) when compared with the NC diet in this study. However, SJ supplementation increased iodine contents in muscle, reduced HSI, and improved liver injury, such as the decrease of glucose (GLU), total bile acid (TBA), and alanine aminotransferase (ALT) in serum, and glycogen and TBA in the liver. Consistently, histological analysis showed that SJ reduced the area of lipid droplet, glycogen, and collagen fiber in the liver (p < 0.05). Thoroughly, the underlying protective mechanisms of SJ supplementation against HC-induced liver injury were studied by liver transcriptome sequencing coupled with pathway analysis. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the differentially expressed genes (DEGs), such as the acetyl-coenzyme A synthetase (acss1), alcohol dehydrogenase (adh), interferon-induced protein with tetratricopeptide repeats 1 (ifit1), aldo-keto reductase family 1 member D1 (akr1d1), cholesterol 7-alpha-monooxygenase (cyp7a1), and UDP-glucuronosyltransferase (ugt), indicated that the pathway of glycolysis/gluconeogenesis was the main metabolic pathway altered in the HC group compared with the NC group. Meanwhile, hepatitis C, primary BA biosynthesis, and drug metabolism-cytochrome P450 were the three main metabolic pathways altered by SJ supplementation when compared with the HC group. Moreover, the BA-targeted metabolomic analysis of the serum BA found that SJ supplementation decreased the contents of taurohyocholic acid (THCA), taurochenodeoxycholic acid (TCDCA), taurolithocholic acid (TLCA), nordeoxycholic acid (NorDCA), and increased the contents of ursocholic acid (UCA), allocholic acid (ACA), and chenodeoxycholic acid (CDCA). In particular, the higher contents of UCA, ACA, and CDCA regulated by SJ were associated with lower liver injury. Overall, these results indicate that the 2.5% supplementation of SJ can be recommended as a functional feed additive for the alleviation of liver injury in swamp eel-fed high-carbohydrate diets.

Four MicroRNAs, miR-13b-3p, miR-278-5p, miR-10483-5p, and miR-10485-5p, Mediate Insecticide Tolerance in Spodoptera frugiperda

Spodoptera frugiperda is the world’s major agricultural pest and has the distinctive features of high fecundity, strong migratory capacity, and high resistance to most insecticides. At present, the control of S. frugiperda in China relies mainly on the spraying of chemical insecticides. MicroRNAs (miRNAs) are a class of small, single-stranded, non-coding RNAs and play crucial regulatory roles in various physiological processes, including the insecticide resistance in insects. However, little is known about the regulatory roles of miRNAs on the resistance of S. frugiperda to insecticides. In the present research, the miRNAs that were differentially expressed after cyantraniliprole, spinetoram, and emamectin benzoate treatment were analyzed by RNA-Seq. A total of 504 miRNAs were systematically identified from S. frugiperda, and 24, 22, and 31 miRNAs were differentially expressed after treatments of cyantraniliprole, spinetoram, and emamectin benzoate. GO and KEGG enrichment analyses were used to predict the function of differentially expressed target genes of miRNAs. Importantly, ten miRNAs were significantly differentially expressed among the treatments of three insecticides. miR-278-5p, miR-13b-3p, miR-10485-5p, and miR-10483-5p were significantly downregulated among the treatments of three insecticides by RT-qPCR. Furthermore, the overexpression of miR-278-5p, miR-13b-3p, miR-10485-5p, and miR-10483-5p significantly increased the mortality of S. frugiperda to cyantraniliprole and emamectin benzoate. The mortality was significantly increased with spinetoram treatment after the overexpression of miR-13b-3p, miR-10485-5p, and miR-10483-5p. These results suggest that miRNAs, which are differentially expressed in response to insecticides, may play a key regulatory role in the insecticide tolerance in S. frugiperda.

Metabolic Soft Spot and Pharmacokinetics: Functionalization of C-3 Position of an Eph-Ephrin Antagonist Featuring a Bile Acid Core as an Effective Strategy to Obtain Oral Bioavailability in Mice

UniPR129, an L-β-homotryptophan conjugate of the secondary bile acid lithocholic acid (LCA), acts as an effective protein-protein interaction (PPI) inhibitor of the Eph-ephrin system but suffers from a poor oral bioavailability in mice. To improve UniPR129 bioavailability, a metabolic soft spot, i.e., the 3α-hydroxyl group on the LCA steroidal ring, was functionalized to 3-hydroxyimine. In vitro metabolism of UniPR129 and 3-hydroxyimine derivative UniPR500 was compared in mouse liver subcellular fractions, and main metabolites were profiled by high resolution (HR-MS) and tandem (MS/MS) mass spectrometry. In mouse liver microsomes (MLM), UniPR129 was converted into several metabolites: M1 derived from the oxidation of the 3-hydroxy group to 3-oxo, M2-M7, mono-hydroxylated metabolites, M8-M10, di-hydroxylated metabolites, and M11, a mono-hydroxylated metabolite of M1. Phase II reactions were only minor routes of in vitro biotransformation. UniPR500 shared several metabolic pathways with parent UniPR129, but it showed higher stability in MLM, with a half-life (t_1/2) of 60.4 min, if compared to a t_1/2 = 16.8 min for UniPR129. When orally administered to mice at the same dose, UniPR500 showed an increased systemic exposure, maintaining an in vitro valuable pharmacological profile as an EphA2 receptor antagonist and an overall improvement in its physico-chemical profile (solubility, lipophilicity), if compared to UniPR129. The present work highlights an effective strategy for the pharmacokinetic optimization of aminoacid conjugates of bile acids as small molecule Eph-ephrin antagonists.

Chromosome Genome Assembly of Cromileptes altivelis Reveals Loss of Genome Fragment in Cromileptes Compared with Epinephelus Species

The humpback grouper (Cromileptes altivelis), an Epinephelidae species, is patchily distributed in the reef habitats of Western Pacific water. This grouper possesses a remarkably different body shape and notably low growth rate compared with closely related grouper species. For promoting further research of the grouper, in the present study, a high-quality chromosome-level genome of humpback grouper was assembled using PacBio sequencing and high-throughput chromatin conformation capture (Hi-C) technology. The assembled genome was 1.013 Gb in size with 283 contigs, of which, a total of 143 contigs with 1.011 Gb in size were correctly anchored into 24 chromosomes. Moreover, a total of 26,037 protein-coding genes were predicted, of them, 25,243 (96.95%) genes could be functionally annotated. The high-quality chromosome-level genome assembly will provide pivotal genomic information for future research of the speciation, evolution and molecular-assisted breeding in humpback groupers. In addition, phylogenetic analysis based on shared single-copy orthologues of the grouper species showed that the humpback grouper is included in the Epinephelus genus and clustered with the giant grouper in one clade with a divergence time of 9.86 Myr. In addition, based on the results of collinearity analysis, a gap in chromosome 6 of the humpback grouper was detected; the missed genes were mainly associated with immunity, substance metabolism and the MAPK signal pathway. The loss of the parts of genes involved in these biological processes might affect the disease resistance, stress tolerance and growth traits in humpback groupers. The present research will provide new insight into the evolution and origin of the humpback grouper.

Serum Bile Acid Profiles Improve Clinical Prediction of Nonalcoholic Fatty Liver in T2DM patients

Background: The present study aimed to assess the ability of serum bile acid profiles to predict the development of nonalcoholic fatty liver (NAFL) in type 2 diabetes mellitus (T2DM) patients. Methods: Using targeted ultraperformance liquid chromatography (UPLC) coupled with triple quadrupole mass spectrometry (TQ/MS), we compared serum bile acid levels in T2DM patients with NAFL (n = 30) and age- and sex-matched T2DM patients without NAFL (n = 36) at the first time. Second, an independent cohort study of T2DM patients with NAFL (n = 17) and age- and sex-matched T2DM patients without NAFL (n = 20) was used to validate the results. The incremental benefits of serum biomarkers, clinical variables alone, or with biomarkers were then evaluated using receiver operating characteristic (ROC) curves and decision curve analysis. The area under the curve (AUC), integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were used to evaluate the biomarker predictive abilities. Results: The serum bile acid profiles in T2DM patients with NAFL were significantly different from T2DM patients without NAFL, as characterized by the significant elevation of LCA, TLCA, TUDCA, CDCA-24G, and TCDCA, which may be potential biomarkers for the identification of NAFL in T2DM patients. Based on the improvement in AUC, IDI, and NRI, the addition of 5 bile acids to a model with clinical variables statistically improved its predictive value. Similar results were found in the validation cohort. Conclusions: These results highlight that the detected biomarkers may contribute to the progression of NAFL in T2DM patients, and these biomarkers particularly in combination may help in the diagnosis of NAFL and allow earlier intervention in T2DM patients.

A fluorescence-based microplate assay for high-throughput screening and evaluation of human UGT inhibitors

Human UDP-glucuronosyltransferase enzymes (hUGTs), one of the most important classes of conjugative enzymes, are responsible for the glucuronidation and detoxification of a variety of endogenous substances and xenobiotics. Inhibition of hUGTs may cause undesirable effects or adverse drug-drug interactions (DDI) via modulating the glucuronidation rates of endogenous toxins or the drugs that are primarily conjugated by the inhibited hUGTs. Herein, to screen hUGTs inhibitors in a more efficient way, a novel fluorescence-based microplate assay has been developed by utilizing a fluorogenic substrate. Following screening of series of 4-hydroxy-1,8-naphthalimide derivatives, we found that 4-HN-335 is a particularly good substrate for a panel of hUGTs. Under physiological conditions, 4-HN-335 can be readily O-glucuronidated by ten hUGTs, such reactions generate a single O-glucuronide with a high quantum yield (Ф = 0.79) and bring remarkable changes in fluorescence emission. Subsequently, a fluorescence-based microplate assay is developed to simultaneously measure the inhibitory effects of selected compound(s) on ten hUGTs. The newly developed fluorescence-based microplate assay is time- and cost-saving, easy to manage and can be adapted for 96-well microplate format with the Z-factor of 0.92. We further demonstrate the utility of the fluorescence-based assay for high-throughput screening of two compound libraries, resulting in the identification of several potent UGT inhibitors, including natural products and FDA-approved drugs. Collectively, this study reports a novel fluorescence-based microplate assay for simultaneously sensing the residual activities of ten hUGTs, which strongly facilitates the identification and characterization of UGT inhibitors from drugs or herbal constituents and the investigations on UGT-mediated DDI.

A broad-spectrum substrate for the human UDP-glucuronosyltransferases and its use for investigating glucuronidation inhibitors

Strong inhibition of the human UDP-glucuronosyltransferase enzymes (UGTs) may lead to undesirable effects, including hyperbilirubinaemia and drug/herb-drug interactions. Currently, there is no good way to examine the inhibitory effects and specificities of compounds toward all the important human UGTs, side-by-side and under identical conditions. Herein, we report a new, broad-spectrum substrate for human UGTs and its uses in screening and characterizing of UGT inhibitors. Following screening a variety of phenolic compound(s), we have found that methylophiopogonanone A (MOA) can be readily O-glucuronidated by all tested human UGTs, including the typical N-glucuronidating enzymes UGT1A4 and UGT2B10. MOA-O-glucuronidation yielded a single mono-O-glucuronide that was biosynthesized and purified for structural characterization and for constructing an LC-UV based MOA-O-glucuronidation activity assay, which was then used for investigating MOA-O-glucuronidation kinetics in recombinant human UGTs. The derived K_m values were crucial for selecting the most suitable assay conditions for assessing inhibitory potentials and specificity of test compound(s). Furthermore, the inhibitory effects and specificities of four known UGT inhibitors were reinvestigated by using MOA as the substrate for all tested UGTs. Collectively, MOA is a broad-spectrum substrate for the human UGTs, which offers a new and practical tool for assessing inhibitory effects and specificities of UGT inhibitors.

Hydroxylated polychlorinated biphenyls (OH-PCBs) exert strong inhibitory effects towards human carboxylesterases (CESs)

Polychlorinated biphenyls (PCBs) have been reported to pose a severe risk towards human health, and hydroxylated polychlorinated biphenyls (OH-PCBs) were potential substances basis for PCBs' toxicity. This study aims to determine the inhibition of OH-PCBs towards human carboxylesterases (CESs), including CES1 and CES2. For phenotypic analysis of CES1 and CES2 activity, we used the hydrolysis metabolism of 2-(2-benzoyl3-methoxyphenyl) benzothiazole (BMBT) and fluorescein diacetate (FD) catalyzed by human liver microsomes (HLMs) as the probe reactions. Preliminary inhibition screening showed that the inhibition potential of OH-PCBs towards CES1 and CES2 increased with the increased numbers of chlorine atoms in OH-PCBs. Both 2'-OH-PCB61 and 2'-OH-PCB65 showed concentration-dependent inhibition towards both CES1 and CES2. Lineweaver-Burk plots showed that 2'-OH-PCB61 and 2'-OH-PCB65 exerted non-competitive inhibition towards CES1 and competitive inhibition towards CES2. The inhibition kinetics parameters (Ki) were 6.8 μM and 7.0 μM for 2'-OH-PCB61 and 2'-OH-PCB65 towards CES1, respectively. The inhibition kinetics parameters (Ki) were 1.4 μM and 1.0 μM for 2'-OH-PCB61 and 2'-OH-PCB65 towards CES2, respectively. In silico docking methods elucidate the contribution of hydrogen bonds and hydrophobic contacts towards the binding of 2'-OH-PCB61 and 2'-OH-PCB65 with CES1 and CES2. All these results will provide a new perspective for elucidation of toxicity mechanism of PCBs and OH-PCBs.

Minor chemical modifications of the aminosteroid derivative RM-581 lead to major impact on its anticancer activity, metabolic stability and aqueous solubility

The aminosteroid (AM) RM-581 is built around a mestranol backbone and has recently emerged as this family's lead candidate, showing in vitro and in vivo potency over different types of cancer, including high fatality pancreatic cancer. To extend the structure-activity relationships (SAR) to other estrane analogs, we synthesized a focused series of RM-581 derivatives at position C3 or C2 of its steroidal core. These new AM derivatives were first tested on a large selection of prostate, breast, pancreatic and ovarian cancer cell lines. The impact of these modifications on metabolic stability (human liver microsomes) was also measured. A SAR study revealed a fine regulation of anticancer activity related to the nature of the substituent. Indeed, the addition of potential prodrug groups like acetate, sulfamate or phosphate (compounds 8, 9 and 10) at C3 of the phenolic counterpart provided better antiproliferative activities than RM-581 in breast and pancreatic cancer cell types while maintaining activity in other cancer cell lines. Also, the phosphate group was highly beneficial on water solubility. However, the bulkier carbamate prodrugs 6 (N,N-dimethyl) and 7 (N,N-diethyl) were less active. Otherwise, carbon homologation (CH₂) at C2 (compound 33) was beneficial to metabolic stability and, in the meantime, this AM conserved the same anticancer activity as RM-581. However, the replacement of the hydroxy or methoxy at C3 by a hydrogen or an acetyl (compound 17 or 21b) was detrimental for anticancer activity, pointing to a crucial molecular interaction of the aromatic oxygen atom at this position. Overall, this work provided a better knowledge of the structural requirements to maintain RM-581's anticancer activity, and also identified minor structural modifications to increase both metabolic stability and water solubility, three important parameters of pharmacological development.

Evaluation of vitamin D biosynthesis and pathway target genes reveals UGT2A1/2 and EGFR polymorphisms associated with epithelial ovarian cancer in African American Women

An association between genetic variants in the vitamin D receptor (VDR) gene and epithelial ovarian cancer (EOC) was previously reported in women of African ancestry (AA). We sought to examine associations between genetic variants in VDR and additional genes from vitamin D biosynthesis and pathway targets (EGFR, UGT1A, UGT2A1/2, UGT2B, CYP3A4/5, CYP2R1, CYP27B1, CYP24A1, CYP11A1, and GC). Genotyping was performed using the custom-designed 533,631 SNP Illumina OncoArray with imputation to the 1,000 Genomes Phase 3 v5 reference set in 755 EOC cases, including 537 high-grade serous (HGSOC), and 1,235 controls. All subjects are of African ancestry (AA). Logistic regression was performed to estimate odds ratios (OR) and 95% confidence intervals (CI). We further evaluated statistical significance of selected SNPs using the Bayesian False Discovery Probability (BFDP). A significant association with EOC was identified in the UGT2A1/2 region for the SNP rs10017134 (per allele OR = 1.4, 95% CI = 1.2-1.7, P = 1.2 × 10-6 , BFDP = 0.02); and an association with HGSOC was identified in the EGFR region for the SNP rs114972508 (per allele OR = 2.3, 95% CI = 1.6-3.4, P = 1.6 × 10-5 , BFDP = 0.29) and in the UGT2A1/2 region again for rs1017134 (per allele OR = 1.4, 95% CI = 1.2-1.7, P = 2.3 × 10-5 , BFDP = 0.23). Genetic variants in the EGFR and UGT2A1/2 may increase susceptibility of EOC in AA women. Future studies to validate these findings are warranted. Alterations in EGFR and UGT2A1/2 could perturb enzyme efficacy, proliferation in ovaries, impact and mark susceptibility to EOC.

The evolution of UDP-glycosyl/glucuronosyltransferase 1E (UGT1E) genes in bird lineages is linked to feeding habits but UGT2 genes is not

UDP-glycosyltransferase (UGT) catalyzes the transfer of glycosyl groups (e.g., glucuronic acid) to exogenous or endogenous chemicals and plays an important role in conjugation reactions. In vertebrates, UGT genes are divided into 5 families: UGT1, UGT2, UGT3, UGT5, and UGT8. Among these UGT enzymes, UGT1 and UGT2 enzymes are known to be important xenobiotic metabolizing enzymes in mammals. However, little is known about UGT1 and UGT2 genes in avian species. In this study, we therefore aimed to classify avian UGT1 and UGT2 genes based on their evolutionary relationships. We also investigated the association between UGT molecular evolution and ecological factors, specifically feeding habits, habitat, and migration. By examining the genomes of 43 avian species with differing ecology, we showed that avian UGT1E genes are divided into 6 groups and UGT2 genes into 3 groups. Correlations between UGT gene count and ecological factors suggested that the number of UGT1E genes is decreasing in carnivorous species. Estimates of selection pressure also support the hypothesis that diet influenced avian UGT1E gene evolution, similar to mammalian UGT1A and UGT2B genes.

Urinary Elimination of Bile Acid Glucuronides under Severe Cholestatic Situations: Contribution of Hepatic and Renal Glucuronidation Reactions

Biliary obstruction, a severe cholestatic complication, causes accumulation of toxic bile acids (BAs) in liver cells. Glucuronidation, catalyzed by UDP-glucuronosyltransferase (UGT) enzymes, detoxifies cholestatic BAs. Using liquid chromatography coupled to tandem mass spectrometry, 11 BA glucuronide (-G) species were quantified in prebiliary and postbiliary stenting serum and urine samples from 17 patients with biliary obstruction. Stenting caused glucuronide- and fluid-specific changes in BA-G levels and BA-G/BA metabolic ratios. In vitro glucuronidation assays with human liver and kidney microsomes revealed that even if renal enzymes generally displayed lower K_M values, the two tissues shared similar glucuronidation capacities for BAs. By contrast, major differences between the two tissues were observed when four human BA-conjugating UGTs 1A3, 1A4, 2B4, and 2B7 were analyzed for mRNA and protein levels. Notably, the BA-24G producing UGT1A3 enzyme, abundant in the liver, was not detected in kidney microsomes. In conclusion, the circulating and urinary BA-G profiles are hugely impacted under severe cholestasis. The similar BA-glucuronidating abilities of hepatic and renal extracts suggest that both the liver and kidney may contribute to the urine BA-G pool.

Profiles and Gender-Specifics of UDP-Glucuronosyltransferases and Sulfotransferases Expressions in the Major Metabolic Organs of Wild-Type and Efflux Transporter Knockout FVB Mice

Hepatic and extrahepatic tissues participate in xenobiotic detoxication, carcinogen activation, prodrug processing, and estrogen regulation through UDP-glucuronosyltransferases (UGTs/Ugts) and sulfotransferases (SULTs/Sults). Wild-type (WT) and efflux transporter knockout (KO) FVB mice have been commonly used to perform the studies of pharmacokinetics, metabolism, and toxicity. We employed the developed UHPLC-MS/MS approach to gain systematic insight on gender-specific of Ugts and Sults in major metabolic organs. Results showed that the liver was the most abundant with Ugts/Sults, followed by the small intestine and the kidney. In the liver, Ugt2b5, Ugt2b1, Ugt1a6a, Ugt1a1, Sult1a1, and Sult1d1 were the major isoforms. The protein amounts of Ugt1a9 were significantly higher in male efflux transporter KO mice than in WT mice, whereas Ugt1a5 and Sult1a1 severely decreased in female efflux transporter KO mice. In WT and efflux transporter KO mice, the expression levels of Ugt1a1, Ugt1a5, Sult1a1, Sult1d1, and Sult3a1 were female-specific, whereas those of Ugt2b1, Ugt2b5, and Ugt2b36 were male-specific. In the small intestine, Ugt1a1, Sult1b1, and Sult2b1 were the major isoforms. The protein levels and gender differences of Ugts/Sults were obviously affected when KO of Mdr1a, and Bcrp1, Mrp1, Mrp2, and Mdr1a, respectively. The KO of efflux transporter affected the protein amounts of Ugts/Sults in the kidney, heart, and spleen. Therefore, a better understanding of the expression profiles and gender-specific of Ugts and Sults in major metabolic organs of WT and efflux transporter KO mice is useful for the evaluation of potential efficacy, and toxicity of corresponding substrates.

Global identification of microRNAs associated with chlorantraniliprole resistance in diamondback moth Plutella xylostella (L.)

The diamondback moth (DBM), Plutella xylostella (L.), is one of the most serious cruciferous pests and has developed high resistance to most insecticides, including chlorantraniliprole. Previous studies have reported several protein-coding genes that involved in chlorantraniliprole resistance, but research on resistance mechanisms at the post-transcription level is still limited. In this study, a global screen of microRNAs (miRNAs) associated with chlorantraniliprole resistance in P. xylostella was performed. The small RNA libraries for a susceptible (CHS) and two chlorantraniliprole resistant strains (CHR, ZZ) were constructed and sequenced, and a total of 199 known and 30 novel miRNAs were identified. Among them, 23 miRNAs were differentially expressed between CHR and CHS, and 90 miRNAs were differentially expressed between ZZ and CHS, of which 11 differentially expressed miRNAs were identified in both CHR and ZZ. Using miRanda and RNAhybrid, a total of 1,411 target mRNAs from 102 differentially expressed miRNAs were predicted, including mRNAs in several groups of detoxification enzymes. The expression of several differentially expressed miRNAs and their potential targets was validated by qRT-PCR. The results may provide important clues for further study of the mechanisms of miRNA-mediated chlorantraniliprole resistance in DBM and other target insects.

Explorative study on the anticancer activity, selectivity and metabolic stability of related analogs of aminosteroid RM-133

RM-133 is a key representative of a new family of aminosteroids reported as potent anticancer agents. Although RM-133 produced interesting results in 4 mouse xenograft cancer models when injected subcutaneously, it needs to be improved to increase its in vivo potency. Thus, to obtain an analog of RM-133 with a better drug potential, a structure-activity relationship study was conducted by synthesizing eleven RM-133-related compounds and addressing their antiproliferative activity on 3 human cancer cells (HL-60, OVCAR-3 and PANC-1) and 3 human normal cell lines (primary ovary, pancreas and renal proximal tubule) as well as their metabolic stability in human liver microsomes. When the 2β-tertiary amine of RM-133 was transformed into a salt or moved to position 3β, the anticancer activity was lost. Modifying the orientation of the side chain of RM-133 increased anticancer activity and selectivity, but led to a drastic loss of stability. The protection of the 3α-hydroxyl of RM-133 by the formation of an ester or a carbamate stabilized the molecule against the phase I metabolic enzymes without affecting its anticancer activity. In comparison to RM-133, the 3-dimethylcarbamate derivative 3 is more selective for cancer cells over normal cells and is much more stable in liver microsomes. Those results support the use of a pro-drug strategy targeting the 3α-hydroxyl of RM-133 as an approach to improve its drug properties. The work presented will enable the development of an optimized anticancer drug of the aminosteroid family that is suitable for a future phase I clinical trial.

Bile acids in drug induced liver injury: Key players and surrogate markers

Bile acid research has gained great momentum since the role of bile acids as key signaling molecules in the enterohepatic circulation was discovered. Their physiological function in regulating their own homeostasis, as well as energy and lipid metabolism make them interesting targets for the pharmaceutical industry in the context of diseases such as bile acid induced diarrhea, bile acid induced cholestasis or nonalcoholic steatohepatitis. Changes in bile acid homeostasis are also linked to various types of drug-induced liver injury (DILI). However, the key question whether bile acids are surrogate markers for monitoring DILI or key pathogenic players in the onset and progression of DILI is under intense investigation. The purpose of this review is to summarize the different facets of bile acids in the context of normal physiology, hereditary defects of bile acid transport and DILI.

Transcriptome composition of the preoptic area in mid-age and escitalopram treatment in male mice

The decrease in serotonergic neurotransmission during aging can increase the risk of neuropsychiatric diseases such as depression in elderly population and decline the reproductive system. Therefore, it is important to understand the age-associated molecular mechanisms of brain aging. In this study, the effect of aging and chronic escitalopram (antidepressant) treatment to admit mice was investigated by comparing transcriptomes in the preoptic area (POA) which is a key nucleus for reproduction. In the mid-aged brain, the immune system-related genes were increased and hormone response-related genes were decreased. In the escitalopram treated brains, transcription-, granule cell proliferation- and vasoconstriction-related genes were increased and olfactory receptors were decreased. Since homeostasis and neuroprotection-related genes were altered in both of mid-age and escitalopram treatment, these genes could be important for serotonin related physiologies in the POA.

Nicotine regulates the expression of UDP-glucuronosyltransferase (UGT) in humanized UGT1 mouse brain

UDP-glucuronosyltransferase (UGT) is a family of enzymes that catalyze the glucuronidation of various compounds, and thereby has an important role in metabolism and detoxification of a large number of xenobiotic and endogenous compounds. UGTs are present highly in the liver and small intestine, while several investigations on quantification of UGT mRNA reported that UGTs were also expressed in the brain. However, reported expression patterns of UGT isoforms in human brain were often incongruous with each other. In the present study, therefore, we investigated UGT mRNA expressions in brains of humanized UGT1 (hUGT1) mice. We found that among the human UGT1 members, UGT1A1, 1A3, and 1A6 were expressed in the brain. We further observed that nicotine (3 mg/kg) induced the expression of UGT1A3 mRNA in the brain, but not liver. While it was not statistically significant, the nicotine treatment resulted in an increase in the chenodeoxycholic acid glucuronide-formation activity in the brain microsomes. UGT1A3 is involved in metabolism of various antidepressants and non-steroidal antiinflammatory drugs, which exhibit their pharmacological effects in the brain. Therefore, nicotine-treated hUGT1 mice might be useful to investigate the role of brain UGT1A3 in the regulation of local levels of these drugs and their response.

Upregulation of UGT2B4 Expression by 3'-Phosphoadenosine-5'-Phosphosulfate Synthase Knockdown: Implications for Coordinated Control of Bile Acid Conjugation

During cholestasis, the bile acid-conjugating enzymes, SULT2A1 and UGT2B4, work in concert to prevent the accumulation of toxic bile acids. To understand the impact of sulfotransferase deficiency on human hepatic gene expression, we knocked down 3'-phosphoadenosine-5'-phosphosulfate synthases (PAPSS) 1 and 2, which catalyze synthesis of the obligate sulfotransferase cofactor, in HepG2 cells. PAPSS knockdown caused no change in SULT2A1 expression; however, UGT2B4 expression increased markedly (∼41-fold increase in UGT2B4 mRNA content). Knockdown of SULT2A1 in HepG2 cells also increased UGT2B4 expression. To investigate the underlying mechanism, we transfected PAPSS-deficient HepG2 cells with a luciferase reporter plasmid containing ∼2 Kb of the UGT2B4 5'-flanking region, which included a response element for the bile acid-sensing nuclear receptor, farnesoid X receptor (FXR). FXR activation or overexpression increased UGT2B4 promoter activity; however, knocking down FXR or mutating or deleting the FXR response element did not significantly decrease UGT2B4 promoter activity. Further evaluation of the UGT2B4 5'-flanking region indicated the presence of distal regulatory elements between nucleotides -10090 and -10037 that negatively and positively regulated UGT2B4 transcription. Pulse-chase analysis showed that increased UGT2B4 expression in PAPSS-deficient cells was attributable to both increased mRNA synthesis and stability. Transfection analysis demonstrated that the UGT2B4 3'-untranslated region decreased luciferase reporter expression less in PAPSS-deficient cells than in control cells. These data indicate that knocking down PAPSS increases UGT2B4 transcription and mRNA stability as a compensatory response to the loss of SULT2A1 activity, presumably to maintain bile acid-conjugating activity.

Expression of hepatic cytochrome P450s and UDP-glucuronosyltransferases in PXR and CAR double humanized mice treated with rifampicin

Nuclear receptor humanized mice models have been developed to predict regulation of drug metabolizing enzyme by xenobiotics. However, limited information is available concerning xenobiotic-induced regulation of drug metabolizing enzymes in multiple nuclear receptor humanized mice. The present study investigated the hepatic regulation of cytochrome P450s (CYPs) and UDP-glucuronosyltransferases (UGTs) in the pregnane X receptor (PXR) and the constitutive androstane receptor double humanized mice treated with rifampicin (RIF; 10mg/kg) for 4 days. RIF increased hepatic microsomal protein and total CYP contents, and CYP reductase activity in the humanized mice, but not in normal mice. Moreover, hepatic induction of Cyp2b10, Cyp2c, and Cyp3a11 were observed only in the RIF-treated humanized mice, suggesting that the humanized mice are sensitive to RIF with respect to the regulation of the hepatic CYP system. Hepatic UGT activities using estradiol, serotonin, and mefenamic acid, but not chenodeoxycholic acid as substrates, increased in the RIF-treated humanized mice, and the glucuronidation activities of estradiol and chenodeoxycholic acid increased in RIF-treated normal mice. These results raise the possibility that a PXR-independent mechanism may be involved in hepatic regulation of UGTs by RIF.

PPARα-UGT axis activation represses intestinal FXR-FGF15 feedback signalling and exacerbates experimental colitis

Bile acids play a pivotal role in the pathological development of inflammatory bowel disease (IBD). However, the mechanism of bile acid dysregulation in IBD remains unanswered. Here we show that intestinal peroxisome proliferator-activated receptor α (PPARα)-UDP-glucuronosyltransferases (UGTs) signalling is an important determinant of bile acid homeostasis. Dextran sulphate sodium (DSS)-induced colitis leads to accumulation of bile acids in inflamed colon tissues via activation of the intestinal peroxisome PPARα-UGTs pathway. UGTs accelerate the metabolic elimination of bile acids, and thereby decrease their intracellular levels in the small intestine. Reduced intracellular bile acids results in repressed farnesoid X receptor (FXR)-FGF15 signalling, leading to upregulation of hepatic CYP7A1, thus promoting the de novo bile acid synthesis. Both knockout of PPARα and treatment with recombinant FGF19 markedly attenuate DSS-induced colitis. Thus, we propose that intestinal PPARα-UGTs and downstream FXR-FGF15 signalling play vital roles in control of bile acid homeostasis and the pathological development of colitis.

Bile acids have been linked to the development of inflammatory bowel diseases, such as colitis. Here the authors show that bile acid levels in mice are controlled by a circular feedback system involving the nuclear receptors PPARα and FXR, and that this system is dysregulated in colitis.

The influence of bile acids homeostasis by cryptotanshinone-containing herbs

BACKGROUND

Herbs might affect the homeostasis of bile acids through influence of multiple metabolic pathways of bile acids.

OBJECTIVE

To investigate the inhibition of cryptotanshinone towards the glucuronidation of LCA, trying to indicate the possible influence of cryptotanshinone-containing herbs towards the homeostasis of bile acids.

METHODS

The LCA-3-glucuronidation and LCA-24-glucuronidation reaction was monitored by LC-MS.

RESULTS

Initial screening showed that 100 µM of cryptotanshinone inhibited LCA-24-glucuronidation and LCA-3-glucuronidation reaction activity by 82.6% and 79.1%, respectively. This kind of inhibition behaviour exerted cryptotanshinone concentrations-dependent and LCA concentrations-independent inhibition behaviour.

CONCLUSION

All these data indicated the possibility of cryptotanshinone's influence towards bile acids metabolism and homeostasis of bile acids.