The proteasome is a promising therapeutic target in the treatment of malignant diseases. Inasmuch as cancer cells are characterized by a rapid synthesis of some proteins, which must be subsequently degraded. A brief description of and some methods for determination of enzymatic activity of proteasomes are given. The methods are used in kinetics studies of proteasome and in the screening of potentially active compounds. Future progress in development of these methods can contribute to more detailed studies of the pathological status of cells as well as to effective pharmacological regimens for patients treated with proteasome inhibitors.
- MeSH
- fluorescenční spektrometrie metody využití MeSH
- lidé MeSH
- management farmakoterapie MeSH
- posttranslační úpravy proteinů MeSH
- proteasomový endopeptidasový komplex * analýza MeSH
- screeningové testy protinádorových léčiv MeSH
- signální dráha UPR MeSH
- ubikvitinace MeSH
- ubikvitinované proteiny * analýza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Anthocyans are biologically active constituents of various berry fruits and they are also contained in nutritional supplements derived from extracts or dry matter from berry fruits. In this study we evaluated the effects of anthocyans on the expression of selected drug-metabolizing phase II genes in primary cultures of human hepatocytes by qRT-PCR. Most of the tested anthocyanidins (6) and anthocyanins (21) did not induce the expression of mRNA of UGT1A/2B members in human hepatocytes. The same can be stated for expression of selected GST genes on the mRNA level. However, some of them e.g. cyanidin-3-O-rutinoside consistently decreased the level of GSTP1 mRNA in all tested cultures. In conclusion, most of the anthocyans did not affect the expression of selected phase II metabolizing enzymes in vitro.
- MeSH
- anthokyaniny farmakologie MeSH
- glukuronosyltransferasa genetika metabolismus MeSH
- hepatocyty účinky léků enzymologie metabolismus MeSH
- II. fáze biotransformace * MeSH
- kultivované buňky MeSH
- lidé MeSH
- xenobiotika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Anthocyanidins and anthocyanins are pharmacologically active constituents of various berry fruits, such as blueberry and cranberry. These compounds are also contained in massively used nutritional supplements based on extracts or dry matter from berry fruits. The current study evaluated the effects of anthocyanidins and anthocyanins on the expression and catalytic activity of major drug-metabolizing enzymes CYP2C9, CYP2A6, CYP2B6, and CYP3A4 in primary cultures of human hepatocytes and human liver microsomes. Expression of mRNA was quantified by qRT-PCR. Expression of proteins was evaluated by Western blotting and immunochemiluminescence. The catalytic activity of CYP enzymes was measured by HPLC using specific enzyme substrates. Tested anthocyanidins (6) and anthocyanins (21) did not induce the expression of mRNA and protein of CYP2C9, CYP2A6, CYP2B6, and CYP3A4 genes in human hepatocytes. Catalytic activities of CYP2C9, CYP2A6, CYP2B6, and CYP3A4 enzymes were inhibited by all anthocyanidins to different extents (e.g., delphinidin inhibits CYP3A4 by >90% at 100 μM with IC50 = 32 μM). Of 21 anthocyanins tested, only cyanidin-3-O-rhamnoside (CYP3A4 by >75% at 100 μM with IC50 = 44 μM) and two glycosides of delphinidin significantly inhibited examined cytochromes P450. It may be concluded that in the ranges of common ingestion of either food or dietary supplement an induction or significant inhibition of CYP2C9, CYP2A6, CYP2B6, and CYP3A4 activity is most probably not expected.
- MeSH
- anthokyaniny farmakologie MeSH
- biokatalýza MeSH
- brusnice s jedlými plody chemie MeSH
- cytochrom P-450 CYP3A genetika metabolismus MeSH
- cytochrom P450 CYP2B6 genetika metabolismus MeSH
- cytochrom P450 CYP2C9 genetika metabolismus MeSH
- hepatocyty enzymologie MeSH
- jaterní mikrozomy enzymologie MeSH
- lidé MeSH
- regulace genové exprese enzymů účinky léků MeSH
- rostlinné extrakty farmakologie MeSH
- Vaccinium macrocarpon chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Proton pump inhibitors omeprazole and lansoprazole contain chiral sulfur atom and they are administered as a racemate, i.e. equimolar mixture of S- and R-enantiomers. The enantiopure drugs esomeprazole and dexlansoprazole have been developed and introduced to clinical practice due to their improved clinical and therapeutic properties. Since omeprazole and lansoprazole are activators of aryl hydrocarbon receptor (AhR) and inducers of CYP1A genes, we examined their enantiospecific effects on AhR-CYP1A pathway in human cancer cells and primary human hepatocytes. We performed gene reporter assays for transcriptional activity of AhR, RT-PCR analyses for CYP1A1/2 mRNAs, western blots for CYP1A1/2 proteins and EROD assay for CYP1A1/2 catalytic activity. Lansoprazole and omeprazole enantiomers displayed differential effects on AhR-CYP1A1/2 pathway. In general, S-enantiomers were stronger activators of AhR and inducers of CYP1A genes as compared to R-enantiomers in lower concentrations, i.e. 1-10 µM for lansoprazole and 10-100 µM for omeprazole. In contrast, R-enantiomers were stronger AhR activators and CYP1A inducers than S-enantiomers in higher concentrations, i.e. 100 µM for lansoprazole and 250 µM for omeprazole. In conclusion, we provide the first evidence of enantiospecific effects of omeprazole and lansoprazole on AhR signaling pathway.
- MeSH
- buněčné linie MeSH
- hepatocyty účinky léků metabolismus MeSH
- inhibitory protonové pumpy chemie farmakologie MeSH
- lanzoprazol chemie farmakologie MeSH
- lidé MeSH
- omeprazol chemie farmakologie MeSH
- receptory aromatických uhlovodíků metabolismus MeSH
- stereoizomerie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
