scholarly journals Human cytochromes P450 in health and disease

2013 ◽  
Vol 368 (1612) ◽  
pp. 20120431 ◽  
Author(s):  
Daniel W. Nebert ◽  
Kjell Wikvall ◽  
Walter L. Miller
Keyword(s):  
Vitamin D ◽  
Cytochrome P450 ◽  
Fatty Acid ◽  
Bile Acid ◽  
Cytochromes P450 ◽  
Gene Families ◽  
The Other ◽  
Chemical Inducers ◽  
Eicosanoid Metabolism ◽  
Health And Disease

There are 18 mammalian cytochrome P450 ( CYP ) families, which encode 57 genes in the human genome. CYP2 , CYP3 and CYP4 families contain far more genes than the other 15 families; these three families are also the ones that are dramatically larger in rodent genomes. Most (if not all) genes in the CYP1 , CYP2 , CYP3 and CYP4 families encode enzymes involved in eicosanoid metabolism and are inducible by various environmental stimuli (i.e. diet, chemical inducers, drugs, pheromones, etc.), whereas the other 14 gene families often have only a single member, and are rarely if ever inducible or redundant. Although the CYP2 and CYP3 families can be regarded as largely redundant and promiscuous, mutations or other defects in one or more genes of the remaining 16 gene families are primarily the ones responsible for P450-specific diseases—confirming these genes are not superfluous or promiscuous but rather are more directly involved in critical life functions. P450-mediated diseases comprise those caused by: aberrant steroidogenesis; defects in fatty acid, cholesterol and bile acid pathways; vitamin D dysregulation and retinoid (as well as putative eicosanoid) dysregulation during fertilization, implantation, embryogenesis, foetogenesis and neonatal development.

scholarly journals Vitamin D deficiency promotes nonalcoholic steatohepatitis through impaired enterohepatic circulation in animal model

2014 ◽  
Vol 307 (9) ◽  
pp. G883-G893 ◽  
Author(s):  
Ming Kong ◽  
Longdong Zhu ◽  
Li Bai ◽  
Xiaohui Zhang ◽  
Yu Chen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Fatty Acid ◽  
Bile Acid ◽  
Vitamin D Deficiency ◽  
Bile Acids ◽  
Nonalcoholic Steatohepatitis ◽  
Enterohepatic Circulation ◽  
Biliary Tree ◽  
Hepatic Lipogenesis ◽  
Endogenous Fatty Acid

Vitamin D deficiency (VDD) or insufficiency is recognized for its association with nonalcoholic steatohepatitis (NASH), whereas the underlying mechanism remains unknown. Using animal models, we found that vitamin D deficiency promoted the high-fat diet (HFD)-initiated simple steatosis into typical NASH, characterized by elevated hepatic inflammation and fat degeneration. The NASH derived from VDD + HFD was related to poor retention of bile acids in the liver and biliary tree, in line with downregulation of the ileal apical sodium-dependent bile acid cotransporter (iASBT). The impediment of hepatic bile acids by the VDD + HFD mice was related to increased expression of hepatic SREBP-1c and fatty acid synthase, suggesting that VDD may upregulate endogenous fatty acid synthesis into NASH through impaired enterohepatic circulation. Administration of 1,25(OH)2VD3 (calcitriol) corrected the NASH phenotypes in line with restoration of iASBT, promotion of bile filling in the biliary tree, suppression of hepatic lipogenesis, and inflammation. Moreover, administration of a bile acid-sequestering agent suppressed ileal fibroblast growth factor 15 expression, leading to increased iASBT expression to restore bile filling in the liver and biliary tree, which ameliorates steatosis and inflammation in the liver. These results suggest a novel mechanism for NASH development, by which VDD downregulates iASBT expression, resulting in a poor bile acid pool and elevation of hepatic lipogenesis and inflammation. In conclusion, vitamin D and bile acid sequestration may be explored as new strategies to treat or prevent NASH.

Agni - Key factor for Shodhananga Snehapana.

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Pavithra. S. ◽  
H. G. Gouda ◽  
Rajalakshmi M. G.
Keyword(s):  
Operative Procedure ◽  
The Other ◽  
Successful Outcome ◽  
Other Hand ◽  
Key Factor ◽  
Health And Disease

Agni is termed as Vaishwanara as it takes the person from Mruthyuloka to Swargaloka. It is an important factor and is equitant to Prana; is one among Dashaprana Ayatana. Agni in Shareera is present in different forms with different actions. It is the responsible factor for both health and disease; on the other hand the successful outcome of treatment is also dependant on Agni. Chikitsa (treatment) is the process of bestowing normalcy which is either brought by Shodhana (purificatory) or Shamana (palliative) Karma. Snehapana is a pre-operative procedure for Shodhana Chikitsa where in Sneha Dravya (medicated fat) is administered for attainment of Upasthita Dosha Avastha and further ease in elimination of the vitiated Doshas. Assessment of Dosha, Dushya, Vyadhi Avastha, Roga Bala, Rogi Bala, Agni, Koshta etc. factors are essential for the attainment of Chikitsa Phala. Assessment of Agni not only helps in understanding Vyadhi but also enables to plan the dosage of Sneha to be administered. Thus this paper is an attempt to throw light on the importance of Agni, assessment of Agni and Agni Bala prior to Shodhananga Snehapana.

Peroxidases from Tulip Bulbs (Tulipa fosteriana, L.) Oxidize Xenobiotics NNitrosodimethylamine and N-Nitroso-N-methylaniline in vitro

1997 ◽  
Vol 62 (11) ◽  
pp. 1804-1814 ◽  
Author(s):  
Marie Stiborová ◽  
Hana Hansíková
Keyword(s):  
Cytochromes P450 ◽  
Kinetic Studies ◽  
The Other ◽  
Maximal Velocity ◽  
Michaelis Constant ◽  
Other Hand ◽  
Plant Peroxidases ◽  
Tulip Bulbs

Tulip bulbs (Tulipa fosteriana, L.) contain peroxidases catalyzing the oxidation of the xenobiotics N-nitrosodimethylamine (NDMA) and N-nitroso-N-methylaniline (NMA). Three anionic (A1, A2, A3) and four cationic (B, C, D, E) peroxidases were purified from this tissue, partially characterized and used for kinetic studies. Demethylation of NDMA and NMA producing formaldehyde is catalyzed by one anionic (A1) and three cationic (C, D, E) peroxidases. The oxidation of NDMA by tulip peroxidases exhibits the Michaelis-Menten kinetics. The apparent Michaelis constant and the maximal velocity values for this substrate were determined. On the other hand, non-Michaelian kinetics for the NMA oxidation were observed with tulip peroxidases. The most abundant cationic peroxidase (peroxidase C) was used for detailed enzymatic studies. In addition to formation of formaldehyde, methylaniline, aniline, 4-aminophenol and phenol were found to be metabolites formed from NMA. Phenol was formed presumably by N-demethylation via a benzenediazonium ion, while methylaniline, aniline and 4-aminophenol were products of denitrosation of the substrate. The efficiencies of plant peroxidases to oxidize NDMA and NMA in vitro are compared with those of cytochromes P450 and discussed.

Chicken Egg Yolk as an Excellent Source of Highly Specific Antibodies Against Cytochromes P450

2004 ◽  
Vol 69 (3) ◽  
pp. 659-673 ◽  
Author(s):  
Petr Hodek ◽  
Tomáš Koblas ◽  
Helena Rýdlová ◽  
Božena Kubíčková ◽  
Miroslav Šulc ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Cytochromes P450 ◽  
Egg Yolk ◽  
Good Alternative ◽  
Invasive Technique ◽  
Cytochrome P450 1A1 ◽  
Orconectes Limosus ◽  
Chicken Egg ◽  
Cytochrome P450 2B4 ◽  
Human Livers

Using chicken antibodies IgY (purified from egg yolks) against mammalian cytochromes P450 and by means of cytochrome P450 marker substrates, we found for the first time the presence of hepatopancreatic cytochrome P450 in crayfishOrconectes limosus(an inducible cytochrome P450 2B-like enzyme) and we were able to detect and quantify cytochrome P450 1A1 in microsomes of human livers. Expression levels of cytochrome P450 1A1 in human livers constituted less than 0.6% of the total hepatic cytochrome P450 complement. The results obtained in our study are clear examples that chicken IgY are suitable for cytochrome P450 detection and quantification. Due to the evolutionary distance, chicken IgY reacts with more epitopes on a mammalian antigen, which gives an amplification of the signal. Moreover, this approach offers many advantages over common mammalian antibody production since chicken egg is an abundant source of antibodies (about 100 mg IgY/yolk) and the egg collection is a non-invasive technique. In the case of antibodies against cytochrome P450 2B4, we documented fast and steady production of highly specific immunoglobulins. Thus, chicken antibodies should be considered as a good alternative to and/or superior substitute for conventional polyclonal antibody produced in mammals.

Five genetic polymorphisms of cytochrome P450 enzymes in the Czech non-Roma and Czech Roma population samples

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Lucie Dlouhá ◽  
Věra Adámková ◽  
Lenka Šedová ◽  
Věra Olišarová ◽  
Jaroslav A. Hubáček ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Genetic Polymorphisms ◽  
Metabolic Pathways ◽  
Cytochromes P450 ◽  
Taqman Assay ◽  
Cytochrome P450 Enzymes ◽  
Roma Population ◽  
Czech Population ◽  
Genotype Frequencies ◽  
Pcr Rflp

AbstractObjectivesCytochromes P450 play a role in human drugs metabolic pathways and their genes are among the most variable in humans. The aim of this study was to analyze genotype frequencies of five common polymorphisms of cytochromes P450 in Roma/Gypsy and Czech (non-Roma) population samples with Czech origin.MethodsRoma/Gypsy (n=302) and Czech subjects (n=298) were genotyped for CYP1A2 (rs762551), CYP2A6 (rs4105144), CYP2B6 (rs3745274) and CYP2D6 (rs3892097; rs1065852) polymorphisms using PCR-RFLP or Taqman assay.ResultsWe found significant allelic/genotype differences between ethnics in three genes. For rs3745274 polymorphism, there was increased frequency of T allele carriers in Roma in comparison with Czech population (53.1 vs. 43.7%; p=0.02). For rs4105144 (CYP2A6) there was higher frequency of T allele carriers in Roma in comparison with Czech population (68.7 vs. 49.8%; p<0.0001). For rs3892097 (CYP2D6) there was more carriers of the A allele between Roma in comparison with Czech population (39.2 vs. 38.2%; p=0.048). Genotype/allelic frequencies of CYP2D6 (rs1065852) and CYP1A2 (rs762551) variants did not significantly differ between the ethnics.ConclusionsThere were significant differences in allelic/genotype frequencies of some, but not all cytochromes P450 polymorphisms between the Czech Roma/Gypsies and Czech non-Roma subjects.

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