The plant extract aristolochic acid (AA), containing aristolochic acid I (AAI) and II (AAII) as major components, causes aristolochic acid nephropathy and Balkan endemic nephropathy, unique renal diseases associated with upper urothelial cancer. Differences in the metabolic activation and detoxification of AAI and AAII and their effects on the metabolism of AAI/AAII mixture in the plant extract might be of great importance for an individual's susceptibility in the development of AA-mediated nephropathies and malignancies. Here, we investigated in vivo metabolism of AAI and AAII after ip administration to Wistar rats as individual compounds and as AAI/AAII mixture using high performance liquid chromatography/electrospray ionization mass spectrometry. Experimental findings were supported by theoretical calculations using density functional theory. We found that exposure to AAI/AAII mixture affected the generation of their oxidative and reductive metabolites formed during Phase I biotransformation and excreted in rat urine. Several Phase II metabolites of AAI and AAII found in the urine of exposed rats were also analyzed. Our results indicate that AAI is more efficiently metabolized in rats in vivo than AAII. Whereas AAI is predominantly oxidized during in vivo metabolism, its reduction is the minor metabolic pathway. In contrast, AAII is mainly metabolized by reduction. The oxidative reaction only occurs if aristolactam II, the major reductive metabolite of AAII, is enzymatically hydroxylated, forming aristolactam Ia. In AAI/AAII mixture, the metabolism of AAI and AAII is influenced by the presence of both AAs. For instance, the reductive metabolism of AAI is increased in the presence of AAII while the presence of AAI decreased the reductive metabolism of AAII. These results suggest that increased bioactivation of AAI in the presence of AAII also leads to increased AAI genotoxicity, which may critically impact AAI-mediated carcinogenesis. Future studies are needed to explain the underlying mechanism(s) for this phenomenon.

• MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
• injekce intraperitoneální MeSH
• krysa rodu Rattus MeSH
• kyseliny aristolochové aplikace a dávkování   metabolismus   moč   MeSH
• potkani Wistar MeSH
• teorie funkcionálu hustoty MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aristolochic acid I MeSH Prohlížeč
• aristolochic acid II MeSH Prohlížeč
• kyseliny aristolochové MeSH

Exposure to aristolochic acid (AA) is associated with human nephropathy and urothelial cancer. The tumour suppressor TP53 is a critical gene in carcinogenesis and frequently mutated in AA-induced urothelial tumours. We investigated the impact of p53 on AAI-induced nephrotoxicity and DNA damage in vivo by treating Trp53(+/+), Trp53(+/-) and Trp53(-/-) mice with 3.5 mg/kg body weight (bw) AAI daily for 2 or 6 days. Renal histopathology showed a gradient of intensity in proximal tubular injury from Trp53(+/+) to Trp53(-/-) mice, especially after 6 days. The observed renal injury was supported by nuclear magnetic resonance (NMR)-based metabonomic measurements, where a consistent Trp53 genotype-dependent trend was observed for urinary metabolites that indicate aminoaciduria (i.e. alanine), lactic aciduria (i.e. lactate) and glycosuria (i.e. glucose). However, Trp53 genotype had no impact on AAI-DNA adduct levels, as measured by 32P-postlabelling, in either target (kidney and bladder) or non-target (liver) tissues, indicating that the underlying mechanisms of p53-related AAI-induced nephrotoxicity cannot be explained by differences in AAI genotoxicity. Performing gas chromatography-mass spectrometry (GC-MS) on kidney tissues showed metabolic pathways affected by AAI treatment, but again Trp53 status did not clearly impact on such metabolic profiles. We also cultured primary mouse embryonic fibroblasts (MEFs) derived from Trp53(+/+), Trp53(+/-) and Trp53(-/-) mice and exposed them to AAI in vitro (50 µM for up to 48 h). We found that Trp53 genotype impacted on the expression of NAD(P)H:quinone oxidoreductase (Nqo1), a key enzyme involved in AAI bioactivation. Nqo1 induction was highest in Trp53(+/+) MEFs and lowest in Trp53(-/-) MEFs; and it correlated with AAI-DNA adduct formation, with lowest adduct levels being observed in AAI-exposed Trp53(-/-) MEFs. Overall, our results clearly demonstrate that p53 status impacts on AAI-induced renal injury, but the underlying mechanism(s) involved remain to be further explored. Despite the impact of p53 on AAI bioactivation and DNA damage in vitro, such effects were not observed in vivo.

• Klíčová slova
• Aristolochic acid I, Carcinogen metabolism, DNA adducts, Mouse embryonic fibroblasts, Mouse models, Tumour suppressor p53,
• MeSH
• cytochrom P-450 CYP1A1 genetika   MeSH
• exprese genu účinky léků   MeSH
• fibroblasty účinky léků   metabolismus   patologie   MeSH
• kultivované buňky MeSH
• kyseliny aristolochové metabolismus   toxicita   MeSH
• mutageny metabolismus   toxicita   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• NAD(P)H dehydrogenasa (chinon) genetika   MeSH
• nádorový supresorový protein p53 genetika   MeSH
• poškození DNA * MeSH
• proximální tubuly ledvin účinky léků   metabolismus   patologie   MeSH
• vyšetření funkce ledvin MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aristolochic acid I MeSH Prohlížeč
• Cyp1a1 protein, mouse MeSH Prohlížeč
• cytochrom P-450 CYP1A1 MeSH
• kyseliny aristolochové MeSH
• mutageny MeSH
• NAD(P)H dehydrogenasa (chinon) MeSH
• nádorový supresorový protein p53 MeSH
• Nqo1 protein, mouse MeSH Prohlížeč
• Trp53 protein, mouse MeSH Prohlížeč

Aristolochic acid (AA) is a plant alkaloid that causes aristolochic acid nephropathy (AAN) and Balkan endemic nephropathy (BEN), unique renal diseases frequently associated with upper urothelial cancer (UUC). This review summarizes the significance of AA-derived DNA adducts in the aetiology of UUC leading to specific A:T to T:A transversion mutations (mutational signature) in AAN/BEN-associated tumours, which are otherwise rare in individuals with UCC not exposed to AA. Therefore, such DNA damage produced by AA-DNA adducts is one rare example of the direct association of exposure and cancer development (UUC) in humans, confirming that the covalent binding of carcinogens to DNA is causally related to tumourigenesis. Although aristolochic acid I (AAI), the major component of the natural plant extract AA, might directly cause interstitial nephropathy, enzymatic activation of AAI to reactive intermediates capable of binding to DNA is a necessary step leading to the formation of AA-DNA adducts and subsequently AA-induced malignant transformation. Therefore, AA-DNA adducts can not only be utilized as biomarkers for the assessment of AA exposure and markers of AA-induced UUC, but also be used for the mechanistic evaluation of its enzymatic activation and detoxification. Differences in AA metabolism might be one of the reasons for an individual's susceptibility in the multi-step process of AA carcinogenesis and studying associations between activities and/or polymorphisms of the enzymes metabolising AA is an important determinant to identify individuals having a high risk of developing AA-mediated UUC.

• Klíčová slova
• DNA adduct formation, aristolochic acid, carcinogenicity, mutagenesis, nephrotoxicity,
• MeSH
• adukty DNA metabolismus   MeSH
• balkánská nefropatie etiologie   metabolismus   MeSH
• biologické markery * MeSH
• karcinogeny chemie   metabolismus   MeSH
• kyseliny aristolochové chemie   metabolismus   MeSH
• lidé MeSH
• náchylnost k nemoci MeSH
• nádorová transformace buněk genetika   metabolismus   MeSH
• urologické nádory etiologie   metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• adukty DNA MeSH
• biologické markery * MeSH
• karcinogeny MeSH
• kyseliny aristolochové MeSH

PURPOSE: Upper-tract urothelial carcinoma (UTUC) is a relatively uncommon disease with limited available evidence on specific topics. The purpose of this article was to review the previous literature to summarize the current knowledge about UTUC epidemiology, diagnosis, preoperative evaluation and prognostic assessment. METHODS: Using MEDLINE, a non-systematic review was performed including articles between January 2000 and February 2016. English language original articles, reviews and editorials were selected based on their clinical relevance. RESULTS: UTUC accounts for 5-10 % of all urothelial cancers, with an increasing incidence. UTUC and bladder cancer share some common risk factors, even if they are two different entities regarding practical, biological and clinical characteristics. Aristolochic acid plays an important role in UTUC pathogenesis in certain regions. It is further estimated that approximately 10 % of UTUC are part of the hereditary non-polyposis colorectal cancer spectrum disease. UTUC diagnosis remains mainly based on imaging and endoscopy, but development of new technologies is rapidly changing the diagnosis algorithm. To help the decision-making process regarding surgical treatment, extent of lymphadenectomy and selection of neoadjuvant systemic therapies, predictive tools based on preoperative patient and tumor characteristics have been developed. CONCLUSIONS: Awareness regarding epidemiology, diagnosis, preoperative evaluation and prognostic assessment changes is essential to correctly diagnose and manage UTUC patients, thereby potentially improving their outcomes.

• Klíčová slova
• Diagnosis, Epidemiology, New technologies, Predictive tools, Prognosis, Risk factor, UTUC,
• MeSH
• dědičné nepolypózní kolorektální nádory epidemiologie   MeSH
• karcinom z přechodných buněk diagnostické zobrazování   epidemiologie   patologie   chirurgie   MeSH
• kyseliny aristolochové metabolismus   MeSH
• ledvinná pánvička diagnostické zobrazování   patologie   chirurgie   MeSH
• lidé MeSH
• lymfadenektomie MeSH
• nádory ledvin diagnostické zobrazování   epidemiologie   patologie   chirurgie   MeSH
• nádory močového měchýře epidemiologie   MeSH
• nádory močovodu diagnostické zobrazování   epidemiologie   patologie   chirurgie   MeSH
• neoadjuvantní terapie MeSH
• předoperační péče MeSH
• prognóza MeSH
• rizikové faktory MeSH
• ureteroskopie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• aristolochic acid I MeSH Prohlížeč
• kyseliny aristolochové MeSH

UNLABELLED: Aristolochic acid I (AAI) is a plant drug found in Aristolochia species that causes aristolochic acid nephropathy, Balkan endemic nephropathy and their associated urothelial malignancies. AAI is activated via nitroreduction producing genotoxic N-hydroxyaristolactam, which forms DNA adducts. The major enzymes responsible for the reductive bioactivation of AAI are NAD(P)H: quinone oxidoreductase and cytochromes P450 (CYP) 1A1 and 1A2. Using site-directed mutagenesis we investigated the possible mechanisms of CYP1A1/1A2/1B1-catalyzed AAI nitroreduction. Molecular modelling predicted that the hydroxyl groups of serine122/threonine124 (Ser122/Thr124) amino acids in the CYP1A1/1A2-AAI binary complexes located near to the nitro group of AAI, are mechanistically important as they provide the proton required for the stepwise reduction reaction. In contrast, the closely related CYP1B1 with no hydroxyl group containing residues in its active site is ineffective in catalyzing AAI nitroreduction. In order to construct an experimental model, mutant forms of CYP1A1 and 1A2 were prepared, where Ser122 and Thr124 were replaced by Ala (CYP1A1-S122A) and Val (CYP1A2-T124V), respectively. Similarly, a CYP1B1 mutant was prepared in which Ala133 was replaced by Ser (CYP1B1-A133S). Site-directed mutagenesis was performed using a quickchange approach. Wild and mutated forms of these enzymes were heterologously expressed in Escherichia coli and isolated enzymes characterized using UV-vis spectroscopy to verify correct protein folding. Their catalytic activity was confirmed with CYP1A1, 1A2 and 1B1 marker substrates. Using (32)P-postlabelling we determined the efficiency of wild-type and mutant forms of CYP1A1, 1A2, and 1B1 reconstituted with NADPH:CYP oxidoreductase to bioactivate AAI to reactive intermediates forming covalent DNA adducts. The S122A and T124V mutations in CYP1A1 and 1A2, respectively, abolished the efficiency of CYP1A1 and 1A2 enzymes to generate AAI-DNA adducts. In contrast, the formation of AAI-DNA adducts was catalyzed by CYP1B1 with the A133S mutation. Our experimental model confirms the importance of the hydroxyl group possessing amino acids in the active center of CYP1A1 and 1A2 for AAI nitroreduction.

• Klíčová slova
• 1A2 and 1B1, DNA adduct formation, aristolochic acid I, aristolochic acid nephropathy, nitroreduction, site-directed mutagenesis of cytochromes P450 1A1,
• MeSH
• adukty DNA metabolismus   MeSH
• aromatické hydroxylasy genetika   metabolismus   MeSH
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P-450 CYP1A2 MeSH
• cytochrom P450 CYP1B1 MeSH
• katalytická doména genetika   MeSH
• katalýza MeSH
• kyseliny aristolochové metabolismus   MeSH
• lidé MeSH
• mutace * MeSH
• mutageneze cílená MeSH
• oxidace-redukce MeSH
• rekombinantní proteiny MeSH
• substrátová specifita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adukty DNA MeSH
• aristolochic acid I MeSH Prohlížeč
• aromatické hydroxylasy MeSH
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P-450 CYP1A2 MeSH
• cytochrom P450 CYP1B1 MeSH
• kyseliny aristolochové MeSH
• rekombinantní proteiny MeSH

Aristolochic acid I (AAI) is a plant alkaloid causing aristolochic acid nephropathy, Balkan endemic nephropathy and their associated urothelial malignancies. AAI is detoxified by cytochrome P450 (CYP)-mediated O-demethylation to 8-hydroxyaristolochic acid I (aristolochic acid Ia, AAIa). We previously investigated the efficiencies of human and rat CYPs in the presence of two other components of the mixed-functions-oxidase system, NADPH:CYP oxidoreductase and cytochrome b₅, to oxidize AAI. Human and rat CYP1A are the major enzymes oxidizing AAI. Other CYPs such as CYP2C, 3A4, 2D6, 2E1, and 1B1, also form AAIa, but with much lower efficiency than CYP1A. Based on velocities of AAIa formation by examined CYPs and their expression levels in human and rat livers, here we determined the contributions of individual CYPs to AAI oxidation in these organs. Human CYP1A2 followed by CYP2C9, 3A4 and 1A1 were the major enzymes contributing to AAI oxidation in human liver, while CYP2C and 1A were most important in rat liver. We employed flexible in silico docking methods to explain the differences in AAI oxidation in the liver by human CYP1A1, 1A2, 2C9, and 3A4, the enzymes that all O-demethylate AAI, but with different effectiveness. We found that the binding orientations of the methoxy group of AAI in binding centers of the CYP enzymes and the energies of AAI binding to the CYP active sites dictate the efficiency of AAI oxidation. Our results indicate that utilization of experimental and theoretical methods is an appropriate study design to examine the CYP-catalyzed reaction mechanisms of AAI oxidation and contributions of human hepatic CYPs to this metabolism.

• Klíčová slova
• contribution of cytochromes P450 in detoxification of aristolochic acid I in human and rat livers, cytochrome P450-mediated detoxification of aristolochic acid I, molecular modeling, plant nephrotoxin and carcinogen aristolochic acid I,
• MeSH
• inhibitory cytochromu P450 farmakologie   MeSH
• jaterní mikrozomy účinky léků   metabolismus   MeSH
• játra účinky léků   metabolismus   MeSH
• katalytická doména MeSH
• katalýza MeSH
• krysa rodu Rattus MeSH
• kyseliny aristolochové škodlivé účinky   chemie   metabolismus   MeSH
• lidé MeSH
• metabolická aktivace MeSH
• metabolická inaktivace MeSH
• metylace účinky léků   MeSH
• molekulární konformace MeSH
• molekulární modely MeSH
• nemoci ledvin etiologie   metabolismus   MeSH
• oxidace-redukce účinky léků   MeSH
• systém (enzymů) cytochromů P-450 chemie   metabolismus   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aristolochic acid I MeSH Prohlížeč
• inhibitory cytochromu P450 MeSH
• kyseliny aristolochové MeSH
• systém (enzymů) cytochromů P-450 MeSH

UNLABELLED: Exposure to the plant nephrotoxin and carcinogen aristolochic acid (AA) leads to the development of AA nephropathy, Balkan endemic nephropathy (BEN) and upper urothelial carcinoma (UUC) in humans. Beside AA, exposure to ochratoxin A (OTA) was linked to BEN. Although OTA was rejected as a factor for BEN/UUC, there is still no information whether the development of AA-induced BEN/UUC is influenced by OTA exposure. Therefore, we studied the influence of OTA on the genotoxicity of AA (AA-DNA adduct formation) in vivo. AA-DNA adducts were formed in liver and kidney of rats treated with AA or AA combined with OTA, but no OTA-related DNA adducts were detectable in rats treated with OTA alone or OTA combined with AA. Compared to rats treated with AA alone, AA-DNA adduct levels were 5.4- and 1.6-fold higher in liver and kidney, respectively, of rats treated with AA combined with OTA. Although AA and OTA induced NAD(P)H: quinone oxidoreductase (NQO1) activating AA to DNA adducts, their combined treatment did not lead to either higher NQO1 enzyme activity or higher AA-DNA adduct levels in ex vivo incubations. Oxidation of AA I (8-methoxy-6-nitrophenanthro[3,4-d]-1,3-dioxole-5-carboxylic acid) to its detoxification metabolite, 8-hydroxyaristolochic acid, was lower in microsomes from rats treated with AA and OTA, and this was paralleled by lower activities of cytochromes P450 1A1/2 and/or 2C11 in these microsomes. Our results indicate that a decrease in AA detoxification after combined exposure to AA and OTA leads to an increase in AA-DNA adduct formation in liver and kidney of rats.

• Klíčová slova
• Aristolochic acid, Aristolochic acid nephropathy, Balkan endemic nephropathy, DNA adducts, Ochratoxin A,
• MeSH
• adukty DNA účinky léků   MeSH
• játra účinky léků   metabolismus   MeSH
• karcinogeny metabolismus   toxicita   MeSH
• krysa rodu Rattus MeSH
• kyseliny aristolochové metabolismus   toxicita   MeSH
• ledviny účinky léků   metabolismus   MeSH
• metabolická inaktivace účinky léků   MeSH
• NAD(P)H dehydrogenasa (chinon) metabolismus   MeSH
• ochratoxiny farmakologie   MeSH
• oxidace-redukce MeSH
• potkani Wistar MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adukty DNA MeSH
• aristolochic acid I MeSH Prohlížeč
• karcinogeny MeSH
• kyseliny aristolochové MeSH
• NAD(P)H dehydrogenasa (chinon) MeSH
• NQO1 protein, rat MeSH Prohlížeč
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH

OBJECTIVES: Balkan endemic nephropathy (BEN) is a chronic progressive fibrosis associated with upper urothelial carcinoma (UUC). Aetiology of BEN is still not fully explained. Although carcinogenic aristolochic acid I (AAI) was proven as the major cause of BEN/UUC, this nephropathy is considered to be multifactorial. Hence, we investigated whether other factors considered as potential causes of BEN [a mycotoxin ochratoxin A (OTA), Cd, Pb, Se and As ions and organic compounds (i.e. phthalates) released from lignite deposits in BEN areas] can influence detoxication of AAI, whose concentrations are crucial for BEN development. METHODS: Oxidation of AAI to 8-hydroxyaristolochic acid I (AAIa) in the presence of Cd, Pb, Se, As ions, dibutylphthalate (DBP), butylbenzylphthalate (BBP), bis(2-ethylhexyl)phthalate (DEHP) and OTA by rat liver microsomes was determined by HPLC. RESULTS: Only OTA, cadmium and selenium ions, and BBP inhibited AAI oxidation by rat liver microsomes. These compounds also inhibited activities of CYP1A1 and/or CYP2C6/11 catalysing AAI demethylation in rat livers. Therefore, these CYP inhibitions can be responsible for a decrease in AAIa formation. When the combined effects of these compounds were investigated, the most efficient inhibition was caused by OTA combined with BBP and selenium ions. CONCLUSION: The results show low effects of BBP, cadmium and selenium ions, and/or their combinations on AAI detoxication. No effects were produced by the other metal ions (Pb, As) and phthalates DBP and DEHP. This finding suggests that they do not influence AAI-mediated BEN development. In contrast, OTA might influence this process, by inhibition of AAI detoxication.

• MeSH
• arsen farmakologie   MeSH
• balkánská nefropatie * MeSH
• ionty MeSH
• jaterní mikrozomy metabolismus   MeSH
• kadmium farmakologie   MeSH
• karcinogeny metabolismus   MeSH
• krysa rodu Rattus MeSH
• kyseliny aristolochové metabolismus   MeSH
• kyseliny ftalové farmakologie   MeSH
• ochratoxiny farmakologie   MeSH
• olovo farmakologie   MeSH
• oxidace-redukce účinky léků   MeSH
• selen farmakologie   MeSH
• těžké kovy farmakologie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aristolochic acid I MeSH Prohlížeč
• arsen MeSH
• ionty MeSH
• kadmium MeSH
• karcinogeny MeSH
• kyseliny aristolochové MeSH
• kyseliny ftalové MeSH
• ochratoxin A MeSH Prohlížeč
• ochratoxiny MeSH
• olovo MeSH
• selen MeSH
• těžké kovy MeSH

UNLABELLED: This review summarizes the results found in studies investigating the enzymatic activation of two genotoxic nitro-aromatics, an environmental pollutant and carcinogen 3-nitrobenzanthrone (3-NBA) and a natural plant nephrotoxin and carcinogen aristolochic acid I (AAI), to reactive species forming covalent DNA adducts. Experimental and theoretical approaches determined the reasons why human NAD(P)H: quinone oxidoreductase (NQO1) and cytochromes P450 (CYP) 1A1 and 1A2 have the potential to reductively activate both nitro-aromatics. The results also contributed to the elucidation of the molecular mechanisms of these reactions. The contribution of conjugation enzymes such as N,O-acetyltransferases (NATs) and sulfotransferases (SULTs) to the activation of 3-NBA and AAI was also examined. The results indicated differences in the abilities of 3-NBA and AAI metabolites to be further activated by these conjugation enzymes. The formation of DNA adducts generated by both carcinogens during their reductive activation by the NOQ1 and CYP1A1/2 enzymes was investigated with pure enzymes, enzymes present in subcellular cytosolic and microsomal fractions, selective inhibitors, and animal models (including knock-out and humanized animals). For the theoretical approaches, flexible in silico docking methods as well as ab initio calculations were employed. The results summarized in this review demonstrate that a combination of experimental and theoretical approaches is a useful tool to study the enzyme-mediated reaction mechanisms of 3-NBA and AAI reduction.

• MeSH
• acetyltransferasy metabolismus   MeSH
• adukty DNA chemie   metabolismus   MeSH
• aromatické hydroxylasy metabolismus   MeSH
• benz(a)anthraceny chemie   metabolismus   MeSH
• biokatalýza MeSH
• enzymy metabolismus   MeSH
• kyseliny aristolochové chemie   metabolismus   MeSH
• lidé MeSH
• molekulární modely * MeSH
• NAD(P)H dehydrogenasa (chinon) metabolismus   MeSH
• sulfotransferasy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• 3-nitrobenzanthrone MeSH Prohlížeč
• acetyltransferasy MeSH
• adukty DNA MeSH
• aristolochic acid I MeSH Prohlížeč
• aromatické hydroxylasy MeSH
• benz(a)anthraceny MeSH
• enzymy MeSH
• kyseliny aristolochové MeSH
• NAD(P)H dehydrogenasa (chinon) MeSH
• sulfotransferasy MeSH

UNLABELLED: 1. Aristolochic acid I (AAI) is the predominant component in plant extract of Aristolochia genus that is involved in development of aristolochic acid nephropathy, Balkan endemic nephropathy and urothelial cancer. The diseases do not develop in all individuals exposed to AAI and patients exhibit different clinical outcomes. Differences in the activities of enzymes catalyzing the metabolism of AAI might be one of the reasons for this individual susceptibility. 2. Understanding which human enzymes are involved in reductive activation of AAI generating AAI-DNA adducts, and/or its detoxication to the O-demethylated metabolite, aristolochic acid Ia (AAIa), is necessary in the assessment of the susceptibility to this compound. 3. This review summarizes the results of the latest studies utilizing genetically engineered mouse models to identify which human and rodent enzymes catalyze the reductive activation of AAI to AAI-DNA adducts and its oxidative detoxication to AAIa in vivo. 4. The use of hepatic cytochrome P450 (Cyp) reductase null (HRN) mice, in which NADPH:Cyp oxidoreductase (Por) is deleted in hepatocytes, Cyp1a1((-/-)), Cyp1a2((-/-)) single-knockout, Cyp1a1/1a2((-/-)) double-knockout and CYP1A-humanized mice revealed that mouse and human CYP1A1 and 1A2, besides mouse NAD(P)H: quinone oxidoreductase, were involved in the activation of AAI but CYP1A1 and 1A2 also oxidatively detoxified AAI.

• MeSH
• adukty DNA metabolismus   MeSH
• cytochrom P-450 CYP1A1 genetika   metabolismus   MeSH
• cytochrom P-450 CYP1A2 genetika   metabolismus   MeSH
• enzymy genetika   metabolismus   MeSH
• inhibitory enzymů farmakologie   MeSH
• karcinogeny metabolismus   farmakokinetika   MeSH
• kyseliny aristolochové metabolismus   farmakokinetika   toxicita   MeSH
• lidé MeSH
• metabolická inaktivace * MeSH
• myši knockoutované * MeSH
• myši MeSH
• NAD(P)H dehydrogenasa (chinon) antagonisté a inhibitory   MeSH
• NADPH-cytochrom c-reduktasa genetika   metabolismus   MeSH
• nemoci ledvin chemicky indukované   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• adukty DNA MeSH
• aristolochic acid I MeSH Prohlížeč
• CYP1A1 protein, human MeSH Prohlížeč
• CYP1A2 protein, human MeSH Prohlížeč
• cytochrom P-450 CYP1A1 MeSH
• cytochrom P-450 CYP1A2 MeSH
• enzymy MeSH
• inhibitory enzymů MeSH
• karcinogeny MeSH
• kyseliny aristolochové MeSH
• NAD(P)H dehydrogenasa (chinon) MeSH
• NADPH-cytochrom c-reduktasa MeSH
• NQO1 protein, human MeSH Prohlížeč