Preparation of highly purified cytochrome P4501A1 from leaping mullet (Liza saliens) liver microsomes and its biocatalytic, molecular and immunochemical properties

Drug interaction potential of Ankaferd blood stopper® in human hepatocarcinoma cells

BACKGROUND

Ankaferd blood stopper® (ABS) is an herbal extract consisting of mixtures of Alpinia officinarum, Gycyrrhiza glabra, Vitis vinifera, Thymus vulgaris, and Urtica dioica plants and has been used in recent years in Turkish medicine as a hemostatic agent. Despite its extensive usage, there is no information available about the drug interaction in HepG2 cells. The current work evaluated the effect of ABS on the expression of CYP1A1-1A2, CYP2E1, and CYP3A4 isozymes that are primarily involved in drug and carcinogen metabolism.

METHODS

We selected HepG2 cells as in vitro cellular models of the human liver. The cells were treated with different concentrations of ABS [0.25%-40% (v/v)]. A crystal violet staining assay was used to determine the cytotoxicity of ABS. We examined drug-metabolizing enzymes, including 7-ethoxyresorufin O-deethylase (CYP1A1), 7-methoxyresorufin O-demethylase (CYP1A2), aniline 4-hydroxylase (CYP2E1), and erythromycin N-demethylase (CYP3A4), in vitro in HepG2 cells. The expression (mRNA, protein) levels of drug-metabolizing enzymes were analyzed by qPCR and Western blotting, respectively.

RESULTS

The EC05 and EC10 values for ABS were 0.37% and 0.52% (v/v), respectively. Therefore, 0.37% and 0.52% (v/v) doses were used for the remaining portion of this study. Investigation of the expression and activity levels revealed that CYP1A1-1A2, CYP2E1, and CYP3A4 activities were not affected by ABS significantly, with qPCR and Western blot results corroborating this result.

DISCUSSION

Our study found that the activity, mRNA, and protein expression levels of CYP isozymes did not change with the application of ABS, suggesting that when humans are exposed to ABS, there may not be any risk associated with clinical drug toxicity, cancer formation, and drug metabolism disorders in humans.

Role of AHR, NF-kB and CYP1A1 crosstalk with the X protein of Hepatitis B virus in hepatocellular carcinoma cells

In this study, it was aimed to elucidate the interaction between aryl hydrocarbon receptor (AHR), nuclear factor-kappa B (NF-kB), and cytochrome P4501A1 (CYP1A1) with hepatitis B virus X protein (HBX) in a human liver cancer cell line (HepG2) transfected with HBX. First, AHR, NF-kB, and CYP1A1 genes were cloned into the appropriate region of the CheckMate mammalian two-hybrid recipient plasmids using a flexi vector system. Renilla and firefly luciferases were quantified using the dual-luciferase reporter assay system to measure the interactions. Secondly, transient transfections of CYP1A1 and NF-kB (RelA) were performed into HBX-positive and HBX-negative HepG2 cells. The mRNA expression of CYP1A1 and NF-kB genes were confirmed with RT-PCR, and cell viability was measured by WST-1. Further verification was assessed by measuring the activity and protein level of CYP1A1. Additionally, CYP1A1/HBX protein-protein interactions were performed with co-immunoprecipitation, which demonstrated no interaction. These results have clearly shown that the NF-kB and AHR genes interact with HBX without involving CYP1A1 and HBX protein-protein interactions. The present study confirms that AHR and NF-kB interaction plays a role in the HBV mechanism mediated via HBX and coordinating the carcinogenic or inflammatory responses; still, the CYP1A1 gene has no effect on this interaction.

Capparis ovata treatment suppresses inflammatory cytokine expression and ameliorates experimental allergic encephalomyelitis model of multiple sclerosis in C57BL/6 mice

Since ancient times, Capparis species have been widely used in traditional medicine to treat various diseases. Our recent investigations have suggested Capparis ovata's potential anti-neuroinflammatory application for the treatment of multiple sclerosis (MS). The present study was designed to precisely determine the underlying mechanism of its anti-neuroinflammatory effect in a mouse model of MS. C. ovata water extract (COWE) was prepared using the plant's fruit, buds, and flower parts (Turkish Patent Institute, PT 2012/04,093). We immunized female C57BL/6J mice with MOG35-55/CFA. COWE was administered at a daily dose of 500mg/kg by oral gavage either from the day of immunization (T1) or at disease onset (T2) for 21days. Gene expression analysis was performed using a Mouse Multiple Sclerosis RT² Profiler PCR Array, and further determinations and validations of the identified genes were performed using qPCR. Whole-genome transcriptome profiling was analyzed using Agilent SurePrint G3 Mouse GE 8X60K microarrays. Immunohistochemical staining was applied to brain sections of the control and treated mice to examine the degree of degeneration. COWE was further fractionated and analyzed phytochemically using the Zivak Tandem Gold Triple Quadrupole LC/MS-MS system. COWE remarkably suppressed the development of EAE in T1, and the disease activity was completely inhibited. In the T2 group, the maximal score was significantly reduced compared with that of the parallel EAE group. The COWE suppression of EAE was associated with a significantly decreased expression of genes that are important in inflammatory signaling, such as TNFα, IL6, NF-κB, CCL5, CXCL9, and CXCK10. On the other hand, the expression of genes involved in myelination/remyelination was significantly increased. Immunohistochemical analysis further supported these effects, showing that the number of infiltrating immune cells was decreased in the brains of COWE-treated animals. In addition, differential expression profiling of the transcriptome revealed that COWE treatment caused the down regulation of a group of genes involved in the immune response, inflammatory response, antigen processing and presentation, B-cell-mediated immunity and innate immune response. Collectively, these results suggest anti-neuroinflammatory mechanisms by which COWE treatment delayed and suppressed the development of EAE and ameliorated the disease in mice with persistent clinical signs.

Inhibitory action of Epilobium hirsutum extract and its constituent ellagic acid on drug-metabolizing enzymes

Epilobium hirsutum (EH) is a medicinal plant for treating various diseases. Despite its wide usage, there is no available information about its potential influences on drug metabolism. The present study was undertaken to determine the in vivo effects of EH on hepatic CYP2B, CYP2C, CYP2D, and CYP3A enzymes that are primarily involved in drug metabolism. Male Wistar rats were injected intraperitoneally with EH water extract (EHWE) and ellagic acid (EA) at a daily dose of 37.5 and 20 mg/kg, respectively, for 9 days and hepatic drug-metabolizing enzymes were assessed at activity, protein and mRNA levels. Erythromycin N-demethylase activity was inhibited by 53 and 21 % in EHWE- and EA-treated rats, respectively. Benzphetamine N-demethylase and 7-benzyloxyresorufin-O-debenzylase activities were decreased by 53 and 43 %, and 57 and 57 % in EHWE-and EA-treated rats, respectively. Moreover, protein levels of CYP2B1, CYP2C6, CYP2D2, and CYP3A1 also decreased by 55, 15, 33, and 82 % as a result of EHWE treatment of rats, respectively. Similarly, CYP2B1, CYP2C6, CYP2D2, and CYP3A1 protein levels decreased by 62, 63, 49, and 37 % with EA treatment, respectively. qRT-PCR analyses also showed that mRNA levels of these enzymes were significantly inhibited with bothEHWE and EA treatments. In conclusion, inhibition of drug clearances leading to drug toxicity because of the lowered activity and expression of drug-metabolizing enzymes might be observed in the people who used EH as complementary herbal remedy that might be contributed by its EA content.

Cloning and expression of a CYP720B orthologue involved in the biosynthesis of diterpene resin acids in Pinus brutia

Cytochrome P450 monooxygenases mediate a broad range of oxidative reactions involved in the biosynthesis of both primary and secondary metabolites in plants. Until now, only two P450 genes, CYP720B1 from Pinus taeda and CYP720B4 from Picea sitchensis, have been functionally characterised and described in the literature. The purpose of this study was to describe the cloning and expression of CYP720B from Pinus brutia due to its suggested role in the synthesis of bioactive compounds used for chemical defence against insects. A PCR product of the P. brutia CYP720B gene was cloned into the pCR8/GW/TOPO cloning vector. After optimising the sequence for codon usage in yeast, it was transferred into the inducible expression vector pYES-DEST52 and transfected into the S. cerevisiae INVSc1 strain. Sequence analysis showed that the P. brutia CYP720B gene contains an open reading frame of 1,464 nucleotides, which encodes a 53,570 Da putative protein of 487 amino acid residues. The putative protein contains the classic heme-binding sequence motif that is conserved in all P450 enzymes. It shares 99 and 61% identity with the deduced amino acid sequences of CYP720B1 from Pinus taeda and CYP720B4 from Picea sitchensis, respectively. Recombinant CYP720B protein expression was confirmed using western blot analysis. Furthermore, recombinant CYP720B was functionally active, showing a Soret peak at approximately 448 nm in the reduced CO difference spectra. These data suggest that the cloned gene is an orthologue of CYP720B in P. brutia and might be involved in DRA biosynthesis.

A comparative study for the evaluation of two doses of ellagic acid on hepatic drug metabolizing and antioxidant enzymes in the rat

The present study was designed to evaluate different doses of ellagic acid (EA) in vivo in rats for its potential to modulate hepatic phases I, II, and antioxidant enzymes. EA (10 or 30 mg/kg/day, intragastrically) was administered for 14 consecutive days, and activity, protein, and mRNA levels were determined. Although the cytochrome P450 (CYP) 2B and CYP2E enzyme activities were decreased significantly, the activities of all other enzymes were unchanged with the 10 mg/kg/day EA. In addition, western-blot and qRT-PCR results clearly corroborated the above enzyme expressions. On the other hand, while the NAD(P)H:quinone oxidoreductase 1 (NQO1), catalase (CAT), glutathione peroxidase (GPX), and glutathione S-transferase (GST) activities were increased significantly, CYP1A, 2B, 2C, 2E, and 19 enzyme activities were reduced significantly with 30 mg/kg/day EA. In addition, CYP2B, 2C6, 2E1, and 19 protein and mRNA levels were substantially decreased by the 30 mg/kg/day dose of EA, but the CYP1A protein, and mRNA levels were not changed. CYP3A enzyme activity, protein and mRNA levels were not altered by neither 10 nor 30 mg/kg/day ellagic acid. These results indicate that EA exerts a dose-dependent impact on the metabolism of chemical carcinogens and drugs by affecting the enzymes involved in xenobiotics activation/detoxification and antioxidant pathways.

Alteration of drug metabolizing enzymes in sulphite oxidase deficiency

The aim of this study was to investigate the possible effects of sulphite oxidase (SOX, E.C. 1.8.3.1) deficiency on xenobiotic metabolism. For this purpose, SOX deficiency was produced in rats by the administration of a low molybdenum diet with concurrent addition of 200 ppm tungsten to their drinking water. First, hepatic SOX activity in deficient groups was measured to confirm SOX deficiency. Then, aminopyrine N-demethylase, aniline 4-hydroxylase, aromatase, caffeine N-demethylase, cytochrome b5 reductase, erythromycin N-demethylase, ethoxyresorufin O-deethylase, glutathione S-transferase, N-nitrosodimethylamine N-demethylase and penthoxyresorufin O-deethylase activities were determined to follow changes in the activity of drug metabolizing enzymes in SOX-deficient rats. Our results clearly demonstrated that SOX deficiency significantly elevated A4H, caffeine N-demethylase, erythromycin N-demethylase and N-nitrosodimethylamine N-demethylase activities while decreasing ethoxyresorufin O-deethylase and aromatase activities. These alterations in drug metabolizing enzymes can contribute to the varying susceptibility and response of sulphite-sensitive individuals to different drugs and/or therapeutics used for treatments.

Drug interaction potential of the seed extract of Urtica urens L. (dwarf nettle)

Dwarf nettle (Urtica urens) seed extract was examined in vivo in the rat for its potential to modulate drug metabolizing enzymes including aminopyrine N-demethylase (APND; CYP2C6), aniline 4-hydroxylase (A4H; CYP2E1), nitrosodimethylamine N-demethylase (NDMA-ND; CYP2E1) erythromycin N-demethylase (ERND; CYP3A1) CYP2D1/2 and glutathione S-transferase (GST). RT-PCR data and western blotting studies clearly demonstrated that CYP2C6 and CYP2E1 mRNA levels were substantially increased after Urtica treatment, while the level of CYP3A1 mRNA decreased and that of CYP2D1/2 remained unchanged. Urtica treatment significantly induced GST activity in the liver, lung and kidney (66-, 46- and 31-fold, respectively) while decreasing that of APND (35-, 61- and 94-fold) and NDMA-ND (23, 28 and 54-fold). ERND activity in liver was reduced 45-fold, but increased in the lung and kidney (78- and 144-fold) after Urtica treatment. These results indicate that Urtica seed extract may have the potential to inhibit and/or induce the metabolism of certain co-administered drugs.