Study on regulation of CYP450 enzyme system to reduce liver toxicity through compatibility of Aconiti Kusnezoffii Radix Cocta with Chebulae Fructus and Glycyrrhizae Radix et Rhizoma / 中国中药杂志

Aconiti Kusnezoffii Radix Cocta is one of the most commonly used medicinal materials in Mongolian medicine. Due to the strong toxicity of Aconiti Kusnezoffii Radix Cocta, Mongolian medicine often uses Chebulae Fructus, Glycyrrhizae Radix et Rhizoma to reduce the toxicity, so as to ensure the curative effect of Aconiti Kusnezoffii Radix Cocta while ensuring its clinical curative effect, but the mechanism is not clear. The aim of this study was to investigate the effects of Chebulae Fructus, Glycyrrhizae Radix et Rhizoma and Aconiti Kusnezoffii Radix Cocta on the mRNA transcription and protein translation of cytochrome P450(CYP450) in the liver of normal rats. Male SD rats were randomly divided into negative control(NC) group, phenobarbital(PB) group(0.08 g·kg~(-1)·d~(-1)), Chebulae Fructus group(0.254 2 g·kg~(-1)·d~(-1)), Glycyrrhizae Radix et Rhizoma group(0.254 2 g·kg~(-1)·d~(-1)), Aconiti Kusnezoffii Radix Cocta group(0.254 2 g·kg~(-1)·d~(-1))and compatibility group(0.254 2 g·kg~(-1)·d~(-1),taking Aconiti Kusnezoffii Radix Cocta as the standard). After continuous administration for 8 days, the activities of total bile acid(TBA), alkaline phosphatase(ALP), amino-transferase(ALT) and aspartate aminotransferase(AST)in serum were detected, the pathological changes of liver tissue were observed, and the mRNA and protein expression levels of CYP1 A2, CYP2 C11 and CYP3 A1 were observed. Compared with the NC group, the serum ALP, ALT and AST activities in the Aconiti Kusnezoffii Radix Cocta group were significantly increased, and the ALP, ALT and AST activities were decreased after compatibility. At the same time, compatibility could reduce the liver injury caused by Aconiti Kusnezoffii Radix Cocta. The results showed that Aconiti Kusnezoffii Radix Cocta could inhibit the expression of CYP1 A2, CYP2 C11 and CYP3 A1, and could up-regulate the expression of CYP1 A2, CYP2 C11 and CYP3 A1 when combined with Chebulae Fructus and Glycyrrhizae Radix et Rhizoma. The level of translation was consistent with that of transcription. The compatibility of Chebulae Fructus and Glycyrrhizae Radix et Rhizoma with Aconiti Kusnezoffii Radix Cocta could up-regulate the expression of CYP450 enzyme, reduce the accumulation time of aconitine in vivo, and play a role in reducing toxicity, and this effect may start from gene transcription.

Association between Maternal Drug Use and Cytochrome P450 Genetic Polymorphisms and the Risk of Congenital Heart Defects in Offspring / 生物医学与环境科学（英文）

OBJECTIVE@#This study aimed to assess the associations between maternal drug use, cytochrome P450 ( CYP450) genetic polymorphisms, and their interactions with the risk of congenital heart defects (CHDs) in offspring.@*METHODS@#A case-control study involving 569 mothers of CHD cases and 652 controls was conducted from November 2017 to January 2020.@*RESULTS@#After adjusting for potential confounding factors, the results show that mothers who used ovulatory drugs (adjusted odds ratio [a OR] = 2.12; 95% confidence interval [ CI]: 1.08-4.16), antidepressants (a OR = 2.56; 95% CI: 1.36-4.82), antiabortifacients (a OR = 1.55; 95% CI: 1.00-2.40), or traditional Chinese drugs (a OR = 1.97; 95% CI: 1.26-3.09) during pregnancy were at a significantly higher risk of CHDs in offspring. Maternal CYP450 genetic polymorphisms at rs1065852 (A/T vs. A/A: OR = 1.53, 95% CI: 1.10-2.14; T/T vs. A/A: OR = 1.57, 95% CI: 1.07-2.31) and rs16947 (G/G vs. C/C: OR = 3.41, 95% CI: 1.82-6.39) were also significantly associated with the risk of CHDs in offspring. Additionally, significant interactions were observed between the CYP450genetic variants and drug use on the development of CHDs.@*CONCLUSIONS@#In those of Chinese descent, ovulatory drugs, antidepressants, antiabortifacients, and traditional Chinese medicines may be associated with the risk of CHDs in offspring. Maternal CYP450 genes may regulate the effects of maternal drug exposure on fetal heart development.

Influencia del polimorfismo de CYP3A4 y CYP3A5 en la farmacocinética de tacrolimus en receptores de trasplante renal. Revisión narrativa / Influence of CYP3A4 and CYP3A5 polymorphism of the pharmacokinetics of tacrolimus in renal transplant recipients. Narrative review

El uso de inhibidores de calcineurina, en particular de tacrolimus como terapia inmunosupresora se ha generalizado a nivel mundial, permitiendo mejorar la tasa de sobrevida del injerto y la calidad de vida del paciente trasplantado. Con el acceso a los estudios de farmacogenética, los grupos de trasplante a nivel mundial se han visto motivados a realizar estudios genéticos que permitan interpretar la influencia de polimorfismos de genes como mTOR, PPP3CA, FK BP1A, FKBP2, y FOXP3, sin embargo, los más estudiados en la población trasplantada para optimizar la dosis de tacrolimus y ciclosporina son los polimorfismos del citocromo p450, CYP3A4 y CYP3A5.El objetivo de la presente revisión narrativa es examinar publicaciones recientes que estudien la relación entre el polimorfismo de CYP3A4/5 y el metabolismo de tacrolimus en pacientes trasplantados renales.Se revisó literatura reciente extraída de los sitios NCBI PubMed y PharmGKB.org en la que se hubiera investigado la influencia de los polimorfismos de CYP3A4/5 en el metabolismo de tacrolimus en trasplantados renales. Se identificó variaciones genéticas de CYP3A4/5 en pacientes trasplantados tratados con tacrolimus que permitirán a los médicos trasplantólogos dosificar de manera precisa el inmunosupresor. El uso de análisis farmacogenéticos permite determinar las variables genéticas del CYP3A4/5, y por lo tanto la toma de decisiones personalizadas en la dosis de inicio y de mantenimiento del inmunosupresor tacrolimus para alcanzar los niveles óptimos y con ello disminuir el riesgo de rechazo, de infecciones asociadas a inmunosupresión, y de toxicidad por el medicamento.

The use of the calcineurin inhibitor tacrolimus as immunosuppressive therapy, has become widespread world-wide, improving the graft's survival rate and the quality of life of the transplanted patient. With access to pharmacogenetic studies, transplant groups worldwide have been motivated to conduct genetic studies to inter-pret the influence of polymorphisms of genes such asmTOR, PPP3CA, FK BP1A, FKBP2, and FOXP3, however the most studied in the transplanted population to optimize the dose of tacrolimus and cyclosporine are those of cytochrome p450,CYP3A4 and CYP3A5. The objective of this narrative review is to examine recent publications studying the relationship betweenCYP3A4/5polymorphism, and tacrolimus metabolism in renal transplant patients. Literature extracted from the NCBI PubMed site and PharmGKB.org, from the past five years, which investigated the influence ofCYP3A4/5polymorphism on tacrolimus metabolism in renal transplants had been reviewed. Genetic variations ofCYP3A4/5 were identified in transplant patients treated with tacrolimus that will allow transplant physicians to dose the immunosuppressant accurately. The use of pharmacogenetic analyses makes it possible to determine the genetic polymorphisms ofCYP3A4/5, and therefore the decision-making cus-tomized at the starting and maintenance dose of the tacrolimus immunosuppressant to achieve optimal levels and thereby reduce the risk of rejection, immunosuppression-associated infections, and drug toxicity.

Genetic diversity of protopine-6-hydroxylase in three medicinal Papaver plants / 中国中药杂志

Sanguinarine is the main active component of the Papaver plants, and protopine-6-hydroxylase(P6 H), involved in the sanguinarine biosynthetic pathway, can oxidize protopine to 6-hydroxyprotopine. The investigation on the diversity of P6 H genes in the medicinal Papaver plants contributes to the acquirement of P6 H with high activity to increase the biosynthesis of sanguinarine. Five P6 H genes in P. somniferum, P. orientale, and P. rhoeas were discovered based on the re-sequencing data of the Papaver species, followed by bioinformatics analysis. With the elongation factor 1α(EF-1α), which exhibits stable expression in the root and stem, as the internal reference gene, the transcription levels of P6H genes in roots and stems of the Papaver plants were detected by real-time fluorescent quantitative PCR. As indicated by the re-sequencing results, there were two genotypes of P6H in P. somniferum and P. orientale, respectively, and only one in P. rhoeas. The bioinformatics analysis showed that the P6 H proteins of the three Papaver plants contained the conserved domain cl12078, which is the characteristic of p450 supergene family, and transmembrane regions. The existence of signal peptide remained verification. Real-time fluorescent quantitative PCR results revealed that the transcription level of P6 H in roots of P. somniferum was about 1.44 times of that in stems(α=0.05). The present study confirmed genetic diversity of P6 H in the three medicinal Papaver plants, which lays a basis for the research on the biosynthesis pathway and mechanism of sanguinarine in Papaver species.

Association of CYP2J2 polymorphism with susceptibility to psoriasis in Turkish population: a case-control study

Abstract Background: Cytochrome P450 2J2 is mostly expressed in extrahepatic tissues; it metabolizes arachidonic acid to epoxyeicosatrienoic acids, with various cardio protective and anti-inflammatory effects. CYP2J2 polymorphism has been identified as a risk factor for cardiovascular diseases, but its association with psoriasis remains unknown. Objective: To evaluate CYP2J2 polymorphism as a risk factor for psoriasis in the Turkish population. Methods: There were 94 patients with psoriasis and 100 age- and sex-matched healthy controls included in the study. Detailed demographic and clinical characteristics were recorded, and Psoriasis Area and Severity Index (PASI) scores were calculated for psoriasis patients. Venous blood samples were collected from all the participants and CYP2J2 50G>T (rs890293) polymorphism was analyzed using polymerase chain reaction (PCR). Results: Both T allele and TT + GT genotype frequencies were increased in psoriasis vulgaris patients compared to the control group (p = 0.024 and p = 0.029 respectively, OR = 2.82, 95% CI: 1.11-7.15) No association between CYP2J2 polymorphism and clinical features of psoriasis was identified. Study limitations: A limited number of patients were included in the study. Conclusion: CYP2J2 50G>T (rs890293) polymorphism was associated with an increased risk for PsV in the Turkish population.

Relationship of anti-tuberculosis drug-induced liver injury and genetic polymorphisms in CYP2E1 and GST

ABSTRACT Setting: Treatment of tuberculosis (TB) can result in Drug-Induced Liver Injury (DILI) since hepatotoxic metabolites are formed during the biotransformation of isoniazid (INH).DILI can be related to the genetic profile of the patient. Single nucleotide polymorphisms in the CYP2E1 gene and GSTM1 and GSTT1 deletion polymorphisms have been associated with adverse events caused by INH. Objective: To characterize the genetic polymorphisms of CYP2E1, GSTT1 and GSTM1 in TB carriers. Design: This is an observational prospective cohort study of 45 patients undergoing treatment of TB. PCR-RFLP and multiplex-PCR were used. Results: The distribution of genotypic frequency in the promoter region (CYP2E1 gene) was: 98% wild genotype and 2% heterozygous. Intronic region: 78% wild genotype; 20% heterozygous and 2% homozygous variant. GST enzyme genes: 24% Null GSTM1 and 22% Null GSTT1. Patients with any variant allele of the CYP2E1 gene were grouped in the statistical analyses. Conclusion: Patients with the CYP2E1 variant genotype or Null GSTT1 showed higher risk of presenting DILI (p = 0.09; OR: 4.57; 95% CI: 0.75-27.6). Individuals with both genotypes had no increased risk compared to individuals with one genotype.

Polycyclic aromatic hydrocarbons degradation by marine-derived basidiomycetes: optimization of the degradation process

ABSTRACT Pyrene and benzo[a]pyrene (BaP) are high molecular weight polycyclic aromatic hydrocarbons (PAHs) recalcitrant to microbial attack. Although studies related to the microbial degradation of PAHs have been carried out in the last decades, little is known about degradation of these environmental pollutants by fungi from marine origin. Therefore, this study aimed to select one PAHs degrader among three marine-derived basidiomycete fungi and to study its pyrene detoxification/degradation. Marasmiellus sp. CBMAI 1062 showed higher levels of pyrene and BaP degradation and was subjected to studies related to pyrene degradation optimization using experimental design, acute toxicity, organic carbon removal (TOC), and metabolite evaluation. The experimental design resulted in an efficient pyrene degradation, reducing the experiment time while the PAH concentration applied in the assays was increased. The selected fungus was able to degrade almost 100% of pyrene (0.08 mg mL-1) after 48 h of incubation under saline condition, without generating toxic compounds and with a TOC reduction of 17%. Intermediate metabolites of pyrene degradation were identified, suggesting that the fungus degraded the compound via the cytochrome P450 system and epoxide hydrolases. These results highlight the relevance of marine-derived fungi in the field of PAH bioremediation, adding value to the blue biotechnology.

Pretentious genomic selection signatures in CYP19A1 gene associated with silent estrous behavior in water buffalo in Pakistan

Background: Poor reproductive efficiency of river buffalos hampers the production capabilities of animals. Buffalos are mainly considered poor breeders owing to the constrained expression of estrus behavior. Failure to display heat signs is an indication of improper functionality of signaling peptides to trigger on a series of behavioral changes, which can be detectable by breeders for timely insemination of females. This might cause an animal to be a repeat breeder. Genomic variations underlying synthesis of signaling peptides can be a useful marker to select superior animals with better reproductive efficiency. In this context, the current study was designed to analyze the CYP19A1 gene in Nili-Ravi buffalo. Results: A total of 97 animals were selected and were divided into two groups on the basis of their heat score. PCR amplification and sequencing of the amplicons were performed using the specific sets of primer, and then, sequences were analyzed for novel variants. A total of 11 polymorphic sites were identified illustrating phenotypic variation in the heat score. Most of the loci were found homologous. Single Nucleotide Polymorphisms (SNPs) were analyzed for association with silent estrus. A three-dimensional protein model was also generated to locate the position of exonic SNPs. Conclusion: This study illustrated that polymorphic sites in the CYP19A1 gene provided potential markers for selection of buffalos with better estrus behavior.

Genetic polymorphisms in the Cytochrome P450 family and squamous cell carcinoma of the oral cavity, pharynx and larynx / Polimorfismos genéticos da família Citocromo P450 e carcinoma de células escamosas de cavidade oral, faringe e laringe

Objective: To analyze the genetic polymorphisms of the cytochrome P450 family and their relationship with squamous cell carcinoma of the oral cavity, pharynx and larynx. Methods: We present a narrative literature review, conducted in Pubmed, Lilacs and Cochrane Databases of articles published in the last five years correlating genetic polymorphisms of the cytochrome P450 family and cancer risk in different populations worldwide. Results: We initially found 65 articles and, after selection criteria, 20 case-control studies with various populations worldwide were eligible. The most studied polymorphisms were those of CYP2E1 and CYP1A1 subfamilies. There is little about the other subfamilies. The association found between polymorphisms and cancer risk amounted to a countless number of variables, amongst them: population, selection methods, racial factors and different modes of exposure to carcinogens, genotyping methods, and nomenclature of the polymorphisms. Conclusion: so far, there is no proven link between genetic polymorphisms of cytochrome P450 family and squamous cell carcinoma of the oral cavity, pharynx and larynx relationship. .

Objetivo: analisar os polimorfismos genéticos da família Citocromo P450 e sua relação com o carcinoma de células escamosas de cavidade oral, faringe e laringe. Métodos: por meio de uma Revisão Narrativa de literatura, realizada nas principais bases de dados Pubmed, Lilacs, e Cochrane Database, de artigos publicados nos últimos cinco anos, correlacionando polimorfismos genéticos da família citocromo P450 e risco de câncer nas diversas populações mundiais. Resultados: foram encontrados inicialmente 65 artigos, que, após critérios de seleção, tornaram elegíveis 20 artigos do tipo caso-controle em diversas populações mundiais. Os polimorfismos mais estudados foram os das subfamílias CYP1A1 e CYP2E1. Pouco existe sobre as demais subfamílias. A associação entre os polimorfismos encontrados e risco de câncer sofreu um incontável número de variáveis, entre elas, população estudada, métodos de seleção, fatores raciais e diferentes modos de exposição aos carcinógenos, métodos de genotipagem, e nomenclatura dos polimorfismos. Conclusão: até o momento, não existe relação comprovada entre os polimorfismos genéticos da família Citocromo P450 e o carcinoma de células escamosas de cavidade oral, faringe e laringe. .

Inter and intra ethnic variation of vitamin K epoxide reductase complex and cytochrome P450 4F2 genetic polymorphisms and their prevalence in South Indian population.

BACKGROUND: Genetic variation in the vitamin K epoxide reductase complex (VKORC1) and cytochrome P450 4F2 (CYP4F2) genes were found to be strongly associated with the oral anticoagulant (OA) dose requirement. The distribution of genetic variation in these two genes was found to show large inter‑ and intra‑ethnic difference. MATERIALS AND METHODS: A total of 470 unrelated, healthy volunteers of South Indians of either sex (age: 18‑60 years) were enrolled for the study. A 5 ml of venous blood was collected and the genomic deoxyribonucleic acid (DNA) was extracted by using phenol‑chloroform extraction method. Real‑time quantitative polymerase chain reaction (RT‑PCR) method was used for genotyping. RESULTS: The variant allele frequencies of VKORC1 rs2359612 (T), rs8050894 (C), rs9934438 (T) and rs9923231 (A) were found to be 11.0%, 11.8%, 11.7% and 12.0%, respectively. The variant allele VKORC1 rs7294 was (80.1%) more frequent and the variant allele CYP4F2 * 3 was found to be 41.8% in South Indians. The allele, genotype and haplotype frequencies of VKORC1 and CYP4F2 gene were distinct from other compared HapMap populations (P < 0.0001). CONCLUSION: The findings of our study provide the basic genetic information for further pharmacogenetic based investigation of OA therapy in the population.

Complex genetic mechanisms in glaucoma: An overview.

Glaucomas comprise a group of hereditary optic neuropathies characterized by progressive and irreversible visual field loss and damage to the optic nerve head. It is a complex disease with multiple molecular mechanisms underlying its pathogenesis. Genetic heterogeneity is the hallmark of all glaucomas and multiple chromosomal loci have been linked to the disease, but only a few genes have been characterized, viz. myocilin (MYOC), optineurin (OPTN), WDR36 and neurotrophin-4 (NTF4) in primary open angle glaucoma (POAG) and CYP1B1 and LTBP2 in congenital and developmental glaucomas. Case-control-based association studies on candidate genes involved in different stages of glaucoma pathophysiology have indicated a very limited involvement. The complex mechanisms leading to glaucoma pathogenesis indicate that it could be attributed to multiple genes with varying magnitudes of effect. In this review, we provide an appraisal of the various efforts in unraveling the molecular mystery in glaucoma and also some future directions based on the available scientific knowledge and technological developments.

CYP2C9 polymorphism studies in the Saudi population

To determine the prevalence of CYP2C9 polymorphism in normal Saudis [controls], in Saudi patients with venous thrombosis, in patients requiring low dose warfarin [study group] for anticoagulation, and to compare our results to those from other populations. Blood from the "control and study" groups was collected from November 2001 to November 2008. The DNA was extracted, stored at -70°C and later tested for the CYP2C9 polymorphism using established methods. Clinical data were collected through direct interview, chart review, and the Saudi Thrombosis and Familial Thrombophilia Registry. All individuals consented. The prevalence of CYP2C9 polymorphisms in the Saudi population was similar to Caucasians and higher than Asian and African. The control [n=670] and patients with venous thrombosis [n=110] groups showed similar prevalence of the normal wild type CYP2C9 and the 2 polymorphisms tested [CYP2C9*2 and CYP2C9*3]. The group that required low dose warfarin [n=25] showed significantly higher CYP2C9 polymorphism, required 40% less warfarin and had a higher rate of bleeding [5% versus 1.8%]. The prevalence of the abnormal polymorphism in the Saudi population of 35.5% is similar to that in Caucasians. Patients with the CYP2C9 polymorphism required 40% less warfarin and had more serious bleeds

effect of thymoquinone on the activities of drug metabolizing enzymes following gentamicin - induced nephrotoxicity in rats

The present study investigated the effects of thymoquinone on the renal activities of drug-metabolizing enzyme following gentamicin-induced nephrotoxicity in Wistar breed rats. Intraperitoneal administration of thymoquinone alone in rats at the dose rate of 10 mg/kg daily for ten consecutive days did not produce toxic effects in the kidney or change its drug metabolizing capacity. However, nephrotoxicity was produced in Rats injected intraperitoneally with gentamicin daily at the dose rate of 80 mg/kg body weight for ten consecutive days, where there was significant increase in the concentrations of serum creatinine and blood urea compared to control rats [P < 0.0005] and those treated with thymoquinone alone [P < 0.0005], or those given thymoquinone and gentamicin concomitantly [10 mg/kg and 80 mg/kg intraperitoneally daily for ten consecutive days, respectively] [P < 0.0005]. In addition, injection of gentamicin illustrated a tendency to decrease, although not statistically significant, in the kidney concentration of reduced glutathione. Furthermore, gentamicin administration resulted in a significant decrease in the renal concentration of cytochrome P-450 [P < 0.05], while it could not produce significant changes in the renal activities of phase II drug metabolizing enzymes namely, UDP-glucuronyltransferase and glutathione-S-transferasc compared to values obtained for control rats and those treated with thymoquinone alone or coadministered with gentamicin. These findings confirm the nephrotoxic effects of gentamicin and its ability to decrease the renal activities of phase I drug metabolizing enzymes as shown by the significant reduction in the concentration of cytochrome P-450 in the kidneys of treated rats. It can be concluded that thymoquinone coadministration with gentamicin can induce protective effects against gentamicin nephrotoxicity accompanied with restoration of the concentration of cytochrome P-450 to normal levels in the kidneys of treated rats

Drugs impact on CYP-450 enzyme family: A pharmacogenetical study of response variation.

Pharmacogenetics is the study of genetic basis in the individual response to drugs. A thorough knowledge of this will lead to a future where tailor-made drugs, suiting an individual, can be used. Scandinavian countries have been known for wide usage of pharmacogenetics and the most widely used application is for genotyping CYP2D6 in treating psychiatric illness. The CYP-450 enzyme, a super family of microsomal drug-metabolizing enzymes, is the most important of enzymes that catalyzes phase-I drug metabolism reaction. CYP2D6 is a member of this family and it has been most intensively studied and the best example of pharmacogenetics variation in drug metabolism. Neuro-transmitter and drug acting CNS viz. codeine, dextromethorphan, metoprolol and tryptyline etc. are well metabolized by this enzyme. Thus, CYP2D6 is one of the most important and responsible enzymes which regulates bioavailability and metabolism of drug. Presently 75 alleles of CYP2D6 have been described which are responsible for variance of metabolism and toxicity of drugs. Thus, by determining variance of CYP2D6 using molecular approaches viz., PCR, real-time PCR, DNA micro-array and molecular docking can determine the adverse effects, drug toxicity, bioavailability and therapeutic potential of new drug.

Association of CYP1A1, CYP1A2, GSTM1 and NAT2 gene polymorphisms with colorectal cancer and smoking.

We investigated CYP1A1*2A, CYP1A1*2C, CYP1A2*1C, CYP1A2*1F, GSTM1 and NAT2 gene polymorphisms, involving enzymes which metabolize many carcinogens, with reference to colorectal cancer risk. The distribution of these genotypes was not associated with risk overall. However, the CYP1A1*2A T/C genotype showed a significant association with colorectal cancer risk in never-smokers (odds ratio [OR], 3.06; 95% confidence interval [95% CI], 1.11-8.40; p = 0.030). The risk of the NAT2 rapid genotype in never-smokers was also statistically significantly increased (OR, 5.38; 95%CI, 1.80-16.1; p = 0.003). Furthermore, the joint effects of NAT2 rapid plus other genotypes were associated with colorectal cancer overall (OR, 3.12; 95%CI, 1.15-8.51; p = 0.026, for NAT2 rapid plus combined CYP1A1*2C Ile/Val and Val/Val, OR, 3.25; 95%CI, 1.09-9.74; p = 0.035, for NAT2 rapid plus CYP1A2*1C G/G, and OR, 4.20; 95%CI, 1.09-16.1; p = 0.037, for NAT2 rapid plus GSTM1 null, respectively). In never-smokers, the joint effects of NAT2 rapid plus other genotypes were remarkable (OR, 15.9; 95%CI, 1.87-135.8; p = 0.011, for NAT2 rapid plus combined CYP1A1*2A T/C and C/C, OR, 5.71; 95%CI, 1.49-21.9; p = 0.011, for NAT2 rapid plus combined CYP1A1*2C Ile/Val and Val/Val, and OR, 9.14; 95%CI, 2.05-40.7; p = 0.004, for NAT2 rapid plus CYP1A2*1F A/A, respectively). The joint effect of CYP1A2*1F A/A plus CYP1A2*1C G/G genotypes was also increased in never-smokers (OR, 6.16; 95%CI, 1.26-30.1; p = 0.025). Our findings suggest that the CYP1A1*2A T/C and NAT2 rapid genotypes is associated with colorectal cancer susceptibility without smoking exposure. These results also indicate that the NAT2 in combination with CYP1A1*2C, CYP1A2*1C, or GSTM1 genotypes may strongly confer susceptibility to colorectal cancer. In particular, the combination of NAT2 plus CYP1A1*2A, CYP1A1*2C, or CYP1A2*1F genotypes, and that of CYP1A2*1F plus CYP1A2*1C genotype may define a group of persons who are genetically susceptible to colorectal cancer in never smokers.

Cytochrome P450 enzyme isoforms and their therapeutic implications: an update.

Clinicians should be cognizant of potential drug drug interactions and become familiar with the substrates, inhibitors and inducers of the common enzymatic pathways responsible for drug metabolism. Our knowledge of and ability to predict drug interactions have improved with growing understanding of substrates, inhibitors and inducers of cytochrome P450 (CYP-450) isoenzymes. These isoenzymes are a major determinant of the pharmacokinetic behavior of numerous drugs. In addition to inhibition and induction, microsomal drug metabolism is affected by genetic polymorphisms, age, nutrition, hepatic disease and endogenous chemicals. Prescribing physicians by understanding the unique characteristics of these isoenzymes may better anticipate and manage drug drug interactions.

The prospect of application of toxicogenetics/pharmcogenetics theory and methods in forensic practice / 法医学杂志

Individual response to drugs, toxicants, environmental chemicals and allergens varies with genotype. Some respond well to these substances without significant consequences, while others may respond strongly with severe consequences and even death. Toxicogenetics and toxicogenomics as well as pharmacogenetics explain the genetic basis for the variations of individual response to toxicants by sequencing the human genome and large-scale identification of genome polymorphism. The new disciplines will provide a new route for forensic specialists to determine the cause of death.

Cytochrome P450's pharmacogenetics in drug development and clinical aspects [review]

cytochrome P450s [CYPs] are members associated heme protein and hepatic microsomal enzymes, which play important role in drugs metabolism and detoxification. Seven of the 57 known human isoforms of P450s responsible for metabolism of more than 90% of the currently used drugs, CYP1A2, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1 and CYP3A4. Some. of them, CYP2D6, CYP2C9 and CYP2C19, have been shown to be polymorphic as a result of single nuclcotide polymorphisms [SNPs], gene deletions, and gene duplications. The effect of the polymorphisms ranges from a complete loss of functional protein to an increase in enzyme activity and can impact the drug development and clinical application. Most pharmaceutical companies have increasingly screened out compounds that are metabolized solely by polymorphic CYPs. Retrospective studies showed that one of the major causes of the new chemical entities [NCE] failure to reach the clinical stage was related to pharmacokinetic and toxicological issues. Therefore the industry has invested in the science and technology of absorption, distribution, metabolism, excretion and toxicity [ADMET] in order to reduce NCE attribution rates.. Drug metabolism is the most important determinant of the ADMET of most compounds and the role CYP450 is predominant. Overall, current trends in the industry have been fueled by increased managed healthcare, the desire to minimize the need for therapeutic drug monitoring and CYP genotyping in medical practice, and a very competitive marketplace