PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 21490593-6 2011 The maximum in vivo inhibition was 59%, suggesting that f(m,CYP3A4) for cortisol and cortisone 6beta-hydroxylation is ~60%. Hydrocortisone 72-80 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 60-66 22741198-2 2012 The activity of cytochrome P450 isoenzyme CYP3A4 was estimated by the ratio of 6-beta-hydroxycortisol and cortisol. Hydrocortisone 93-101 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 42-48 20515961-0 2010 Oxcarbazepine accelerates cortisol elimination via cytochrome P450 3A4 induction. Hydrocortisone 26-34 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 51-70 21114969-8 2011 CONCLUSION: CYP3A4 variant alleles are present at a low frequency in the Bangladeshi population whereas 50% of the Bangladeshi population carrying a CYP3A5*3/*3 genotype appear to show lower 6beta-hydroxy-cortisol/cortisol ratios compared with those with a CYP3A5*1/*1 genotype. Hydrocortisone 205-213 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 12-18 20515961-7 2010 This study shows that OXC-induced CYP3A4 activity increases cortisol elimination. Hydrocortisone 60-68 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 34-40 19959402-3 2010 The metabolic ratio (MR) of the concentration of 6beta-hydroxycortisol (6beta-OHC) to cortisol (MR 6beta-OHC/cortisol) in human urine had been proposed as an endogenous marker for CYP3A activity. Hydrocortisone 62-70 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 180-185 19959402-3 2010 The metabolic ratio (MR) of the concentration of 6beta-hydroxycortisol (6beta-OHC) to cortisol (MR 6beta-OHC/cortisol) in human urine had been proposed as an endogenous marker for CYP3A activity. Hydrocortisone 86-94 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 180-185 19690646-0 2007 Study of the Urinary Ratio of 6 beta-Hydroxycortisol/Cortisol as a Biomarker of CYP3A4 Activity in Egyptian Patients with Chronic Liver Diseases. Hydrocortisone 53-61 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 80-86 19701237-0 2009 Evaluation of CYP3A activity in humans using three different parameters based on endogenous cortisol metabolism. Hydrocortisone 92-100 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 14-19 19621007-2 2009 However, one should not expect any prediction success for drugs primarily metabolized by the major cytochrome P450 enzyme, CYP3A4, whether one uses an exogenous drug or an endogenous metabolic process, such as the oxidation of cortisol. Hydrocortisone 227-235 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 123-129 16433874-8 2006 CYP3A4 induction was assessed by ratios of urinary 6beta-hydroxycortisol : cortisol (6beta-OHC : C) obtained via 24 h and morning-spot sampling techniques. Hydrocortisone 64-72 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-6 16842393-1 2006 AIMS: A non-invasive proposed method for measuring CYP3A activity is the urinary 6beta-hydroxycortisol:cortisol ratio. Hydrocortisone 94-102 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 51-56 16842393-3 2006 This investigation evaluated the relationship between a validated, biomarker, intravenous midazolam clearance and the urinary cortisol ratio under constitutive conditions and with the influence of a moderate CYP3A inhibitor. Hydrocortisone 126-134 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 208-213 16842393-9 2006 Larger interindividual and intra-individual variability in CYP3A activity was observed in 6beta-hydroxycortisol:cortisol ratios compared with midazolam clearances. Hydrocortisone 103-111 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 59-64 17364054-5 2006 The 6betaOH-cortisol/cortisol ratio in an individual with CYP3A4*2/*2 genotype was 7.408, which corresponded to "slow metabolizer" phenotype in this sample. Hydrocortisone 12-20 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 58-64 17364054-5 2006 The 6betaOH-cortisol/cortisol ratio in an individual with CYP3A4*2/*2 genotype was 7.408, which corresponded to "slow metabolizer" phenotype in this sample. Hydrocortisone 21-29 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 58-64 16675933-6 2006 To add to the complexity, endocrine and paracrine cortisol levels and actions depend much on the activity of metabolizing enzymes, such as 11-beta-hydroxysteroid dehydrogenase type-1 and CYP3A. Hydrocortisone 50-58 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 187-192 16183337-0 2005 Simultaneous determination of 6beta-hydroxycortisol and cortisol in human urine and plasma by liquid chromatography with ultraviolet absorbance detection for phenotyping the CYP3A activity. Hydrocortisone 43-51 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 174-179 16454691-9 2006 Erythromycin, midazolam and cortisol are commonly used to monitor in vivo hepatic CYP3A activity. Hydrocortisone 28-36 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 82-87 15657405-2 2005 We developed a novel method for estimating the interpatient variability of CYP3A4 activity by the urinary metabolite of exogenous cortisol (6-beta-hydroxycortisol [6-beta-OHF]). Hydrocortisone 130-138 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 75-81 16261523-2 2005 It has been shown to induce the activity of cytochrome P-450 3A4 (CYP3A4) and to increase the clearance of numerous drugs and steroids such as cortisol and ethinyl estradiol. Hydrocortisone 143-151 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 44-64 16261523-2 2005 It has been shown to induce the activity of cytochrome P-450 3A4 (CYP3A4) and to increase the clearance of numerous drugs and steroids such as cortisol and ethinyl estradiol. Hydrocortisone 143-151 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 66-72 15545313-1 2004 The present study determined the interindividual and intrandividual variability of the urinary 6beta-hydroxycortisol/cortisol ratio, a useful marker for CYP3A induction and inhibition in Chinese subjects. Hydrocortisone 108-116 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 153-158 15650881-6 2005 CYP3A4 activity was determined by the ratio of 6-hydroxycortisol to free cortisol (6-OHC/FC) in the morning spot urine with a high-throughput liquid chromatography-tandem mass spectrometry method. Hydrocortisone 56-64 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-6 15770075-12 2005 The urinary 6beta-hydroxycortisol/cortisol concentration ratio following ITZ administration for 7 consecutive days was about half of that before the start of ITZ administration, indicating that CYP3A4 metabolic activity was inhibited by administration of ITZ. Hydrocortisone 25-33 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 194-200 14751784-0 2004 Simultaneous determination of 6beta-hydroxycortisol and cortisol in human urine by liquid chromatography with ultraviolet absorbance detection for phenotyping the CYP3A activity determined by the cortisol 6beta-hydroxylation clearance. Hydrocortisone 43-51 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 163-168 15266218-3 2004 In addition, the inhibitory effect of these constituents on CYP3A4-mediated metabolism was determined by using cortisol as a model compound. Hydrocortisone 111-119 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 60-66 15016124-1 2004 The urinary ratio of 6beta-hydroxycortisol to cortisol (6beta-OHF/F) is considered to be the simplest and most practical method for estimation of hepatic cytochrome P450 3A4 (CYP3A4) activity as a non-invasive marker of human in vivo CYP3A4 activity. Hydrocortisone 34-42 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 175-181 15016124-1 2004 The urinary ratio of 6beta-hydroxycortisol to cortisol (6beta-OHF/F) is considered to be the simplest and most practical method for estimation of hepatic cytochrome P450 3A4 (CYP3A4) activity as a non-invasive marker of human in vivo CYP3A4 activity. Hydrocortisone 34-42 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 234-240 15025748-5 2004 RESULTS: The ratios of the treatment to baseline values for CYP3A4 using cortisol as the probe were 1.5 [95% confidence interval (CI) 1.3, 1.9] for males, and 1.9 (1.1, 3.0) for females. Hydrocortisone 73-81 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 60-66 15016124-1 2004 The urinary ratio of 6beta-hydroxycortisol to cortisol (6beta-OHF/F) is considered to be the simplest and most practical method for estimation of hepatic cytochrome P450 3A4 (CYP3A4) activity as a non-invasive marker of human in vivo CYP3A4 activity. Hydrocortisone 34-42 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 154-173 14605865-12 2004 All subjects demonstrated a marked induction of hepatic microsomal CYP3A analyzed by the excretion ratio of 6beta-hydroxycortisol to cortisol from a mean baseline concentration of 5.6 U to 50.5 U. Hydrocortisone 121-129 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 67-72 14570755-1 2003 This study uses stable isotope methodology to evaluate the validity of 6beta-hydroxylation clearance of endogenous cortisol as a new index for in vivo CYP3A phenotyping in humans. Hydrocortisone 115-123 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 151-156 14715379-1 2004 Cortisol is metabolized to 6beta-hydroxycortisol by human cytochrome p450-3A4 (CYP3A4), an important enzyme involved in the metabolism of a variety of exogenous and endogenous compounds. Hydrocortisone 0-8 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 58-77 14715379-1 2004 Cortisol is metabolized to 6beta-hydroxycortisol by human cytochrome p450-3A4 (CYP3A4), an important enzyme involved in the metabolism of a variety of exogenous and endogenous compounds. Hydrocortisone 0-8 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 79-85 14715379-8 2004 These results indicated that urinary 6beta-hydroxycortisol to cortisol ratios measured in a spot urine sample may reflect the level of this biomarker over a relatively longer time period in Caucasian women, and thus, it can be used in epidemiologic studies as a biomarker to evaluate the association between CYP3A4 activity and disease risk. Hydrocortisone 50-58 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 308-314 14570755-8 2003 5-fold) in the labeled cortisol renal clearance suggest that the urinary ratio 6beta-OHF/F, a function of 6beta-hydroxylation clearance and renal clearance of cortisol, does not always reflect the in vivo CYP3A activity. Hydrocortisone 23-31 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 205-210 14570755-9 2003 When a macrolide antibiotic, clarithromycin, was administered to a healthy volunteer in a dose of 200 mg every 12 h for 6 days, the inhibitory effects of clarithromycin on the in vivo CYP3A activity were clearly seen by the 6beta-hydroxylation clearance of endogenous cortisol but not by the urinary ratio 6beta-OHF/F. Hydrocortisone 268-276 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 184-189 12167569-5 2002 CYP3A genes lack a consensus glucocorticoid receptor response element and yet are highly induced by classical glucocorticoids such as hydrocortisone and dexamethasone. Hydrocortisone 134-148 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-5 12451288-1 2002 The frequency distribution of CYP3A activity was investigated by measuring ratios of urinary 6beta-hydroxycortisol to free cortisol in 487 healthy subjects to determine whether a genetic polymorphism for this cytochrome enzyme exists in "native-born" Japanese persons. Hydrocortisone 106-114 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 30-35 11160617-4 2001 In cultured cells, the presence of pgp increased the apparent K(m) for the 6beta-hydroxylase activity of CYP3A4 toward testosterone and cortisol by a factor of 1.7 and 4, respectively. Hydrocortisone 136-144 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 105-111 11181494-13 2001 When compared with healthy Chinese population data, the 6beta-hydroxycortisol to free cortisol ratio data suggested that these alleles (CYP3A4*4, CYP3A4*5, and CYP3A4*6) may decrease the CYP3A4 activity. Hydrocortisone 69-77 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 136-142 11549205-1 2001 OBJECTIVE: The urinary ratio of 6beta-hydroxycortisol to cortisol is known as a possible marker of CYP3A4 activity. Hydrocortisone 45-53 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 99-105 11303593-1 2001 The ratio of urinary 6beta-hydroxycortisol:cortisol is a measure of the activity of cytochrome p450 3A4 (CYP3A4). Hydrocortisone 34-42 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 84-103 11303593-1 2001 The ratio of urinary 6beta-hydroxycortisol:cortisol is a measure of the activity of cytochrome p450 3A4 (CYP3A4). Hydrocortisone 34-42 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 105-111 10772626-0 2000 Regulation of the CYP3A4 gene by hydrocortisone and xenobiotics: role of the glucocorticoid and pregnane X receptors. Hydrocortisone 33-47 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 18-24 11522047-2 2001 To accomplish this goal, the in vivo activity of CYP3A was estimated by measuring the 24-hour urinary excretion of 6beta-hydroxycortisol (6beta-OHC) and by calculating 24-hour ratio of 6beta-hydroxycortisol to urinary free cortisol (6beta-OHC/UFC ratio). Hydrocortisone 128-136 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 49-54 10829051-3 2000 We developed a new method for the estimation of CYP3A4 activity by measuring urinary cortisol metabolite after administration of exogenous cortisol. Hydrocortisone 85-93 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 48-54 10829051-3 2000 We developed a new method for the estimation of CYP3A4 activity by measuring urinary cortisol metabolite after administration of exogenous cortisol. Hydrocortisone 139-147 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 48-54 10829051-14 2000 CONCLUSION: The interpatient variability of CYP3A4 activity and docetaxel CL could be predicted by measuring T6beta-OHF after cortisol administration. Hydrocortisone 126-134 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 44-50 10772626-3 2000 Hydrocortisone produces a dose-dependent increase in CYP3A4 activation, a response that is increased in the presence of either receptor. Hydrocortisone 0-14 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 53-59 10772626-5 2000 In addition, the hydrocortisone dose-response curve falls within the physiological blood level concentration of this steroid, implicating a regulatory role for hydrocortisone in the basal level of CYP3A4 expression. Hydrocortisone 17-31 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 197-203 10772626-5 2000 In addition, the hydrocortisone dose-response curve falls within the physiological blood level concentration of this steroid, implicating a regulatory role for hydrocortisone in the basal level of CYP3A4 expression. Hydrocortisone 160-174 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 197-203 10611140-9 2000 This has been confirmed subsequently in a clinical study, with 6beta-hydroxycortisol/cortisol ratios as marker of CYP3A4 activity. Hydrocortisone 76-84 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 114-120 10805065-0 2000 Circadian variation of the urinary 6beta-hydroxycortisol to cortisol ratio that would reflect hepatic CYP3A activity. Hydrocortisone 48-56 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 102-107 10805065-2 2000 The aim of this study was to assess the intra-individual diurnal variation and day-to-day variation of the urinary 6beta-hydroxycortisol to cortisol ratio, a noninvasive index of human CYP3A activity. Hydrocortisone 128-136 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 185-190 10073736-1 1999 AIMS: To assess CYP3A enzyme activity in human neonates by measuring the urinary 6beta-hydroxycortisol/cortisol (6beta-OHF/C) ratio. Hydrocortisone 94-102 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-21 10354961-1 1999 The urinary ratio of 6-beta-hydroxycortisol/cortisol has been used as a noninvasive probe for human cytochrome P450 3A4 isoforms (CYP3A4). Hydrocortisone 35-43 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 100-119 10354961-1 1999 The urinary ratio of 6-beta-hydroxycortisol/cortisol has been used as a noninvasive probe for human cytochrome P450 3A4 isoforms (CYP3A4). Hydrocortisone 35-43 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 130-136 8349787-1 1993 Placenta and endometrium carry out steroidogenic biotransformation reactions such as 6-beta-hydroxylation of cortisol, a reaction characteristic of the dominant family of cytochromes P450 in human liver, CYP3A. Hydrocortisone 109-117 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 204-209 9753209-3 1998 Known inducers of CYP3A, such as rifampin, phenytoin, carbamazepine, and phenobarbital, increase the urinary excretion of 6beta-hydroxycortisol and the ratio of 6beta-hydroxycortisol to cortisol. Hydrocortisone 135-143 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 18-23 9492385-7 1998 A high CYP3A4 activity in the patient is consistent with the repeated administration of methylprednisolone for 14 days before paclitaxel treatment, a compound known to induce the CYP3A isoform, and with the increased ratio of 6beta-hydroxycortisol/cortisol in urine, an index of CYP3A activity. Hydrocortisone 239-247 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 7-13 9492385-7 1998 A high CYP3A4 activity in the patient is consistent with the repeated administration of methylprednisolone for 14 days before paclitaxel treatment, a compound known to induce the CYP3A isoform, and with the increased ratio of 6beta-hydroxycortisol/cortisol in urine, an index of CYP3A activity. Hydrocortisone 239-247 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 7-12 8608525-2 1996 This study investigated CYP3A4 activity, which metabolically activates procarcinogens such as aflatoxin B1, by measuring the urinary 6 beta-hydroxycortisol (6 beta OHF) to free cortisol (F) ratio in patients with hepatocellular carcinoma (HCC) and other chronic liver diseases. Hydrocortisone 147-155 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 24-30 9855326-0 1998 Cytochrome P450 3A4 activity in premenopausal and postmenopausal women, based on 6-beta-hydroxycortisol:cortisol ratios. Hydrocortisone 95-103 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-19 9855326-1 1998 STUDY OBJECTIVE: To characterize cytochrome P450 (CYP) 3A4 activity in premenopausal and postmenopausal women by evaluating the urinary 6-beta-hydroxycortisol:cortisol ratio. Hydrocortisone 150-158 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 33-58 9855326-7 1998 CONCLUSION: Cytochrome P450 3A4 activity as measured by 6-beta-hydroxy cortisol:cortisol ratio did not differ by week of menstrual cycle, suggesting no menstrual cycle-related changes. Hydrocortisone 71-79 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 12-31 8700118-1 1996 It has been proposed that excessive intrarenal conversion of cortisol to 6 beta-hydroxycortisol by CYP3A may mediate increased tubular reabsorption of sodium, leading to a state of mild volume expansion and the clinical phenotype of salt-sensitive hypertension. Hydrocortisone 61-69 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 99-104 7858720-1 1994 The ratio of the hydrophilic metabolite 6 beta-hydroxycortisol to its parent compound cortisol has recently been demonstrated to be a specific marker for human CYP3A oxygenase activity. Hydrocortisone 54-62 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 160-165 8265621-1 1993 Human cytochrome P450 3A4 is recognized as the catalyst for the oxygen-dependent metabolism of a diverse group of medically important chemicals, including the immunosuppressive agent cyclosporin; macrolide antibiotics, such as erythromycin; drugs such as benzphetamine, nifedipine, and cocaine; and steroids; such as cortisol and testosterone to name but a few. Hydrocortisone 317-325 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 6-25 1732074-0 1992 Heterogeneity of CYP3A isoforms metabolizing erythromycin and cortisol. Hydrocortisone 62-70 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 17-22 1302569-0 1992 Urinary 6 beta-hydroxycortisol/cortisol ratios measured by high-performance liquid chromatography for use as a biomarker for the human cytochrome P-450 3A4. Hydrocortisone 22-30 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 135-155 1302569-1 1992 Cortisol is metabolized to 6 beta-hydroxycortisol by the human cytochrome P-450 3A4, an enzyme implicated in the critical epoxidation reactions of aflatoxin B1 and certain polycyclic aromatic hydrocarbons. Hydrocortisone 0-8 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 63-83 1302569-4 1992 Using the 6 beta-hydroxycortisol:cortisol ratio as a marker of cytochrome P-450 3A4 activity adjusts for the circadian fluctuation in cortisol levels, providing a determination that is consistent over a 24-h period, obviating the need for 24-h urine collections. Hydrocortisone 24-32 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 63-83 1302569-4 1992 Using the 6 beta-hydroxycortisol:cortisol ratio as a marker of cytochrome P-450 3A4 activity adjusts for the circadian fluctuation in cortisol levels, providing a determination that is consistent over a 24-h period, obviating the need for 24-h urine collections. Hydrocortisone 33-41 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 63-83 1454750-6 1992 However, CYP3A is composed of at least four enzymes and as the enzyme(s) responsible for cortisol 6 beta-hydroxylation is (are) not perfectly known, it can not be excluded that a genetic polymorphism does exist for one enzyme of this family. Hydrocortisone 89-97 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 9-14 1732074-4 1992 New noninvasive tests of CYP3A strongly suggest cortisol 6 beta-hydroxylation and erythromycin N-demethylation are performed by distinct CYP3A isoforms. Hydrocortisone 48-56 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 25-30 1732074-4 1992 New noninvasive tests of CYP3A strongly suggest cortisol 6 beta-hydroxylation and erythromycin N-demethylation are performed by distinct CYP3A isoforms. Hydrocortisone 48-56 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 137-142 34664787-0 2021 Studies on CYP3A activity during the menstrual cycle as measured by urinary 6beta-hydroxycortisol/cortisol. Hydrocortisone 98-106 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 11-16 34880651-5 2021 The activity of CYP3A4 isoenzyme was measured as the ratio of the concentrations of cortisol and 6beta-hydroxycortisol. Hydrocortisone 84-92 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-22 34881490-13 2021 The 6beta-OHF/cortisol ratio could be an index of CYP3A activity in clinical setting. Hydrocortisone 14-22 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 50-55 34664787-1 2021 The 6beta-OH-cortisol/cortisol ratio (6beta-OHC/C) in urine is an endogenous marker of drug-metabolizing enzyme cytochrome P450 3A (CYP3A). Hydrocortisone 22-30 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 112-130 34664787-1 2021 The 6beta-OH-cortisol/cortisol ratio (6beta-OHC/C) in urine is an endogenous marker of drug-metabolizing enzyme cytochrome P450 3A (CYP3A). Hydrocortisone 22-30 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 132-137 35589097-1 2022 The feasibility of taking the ratio of 6beta-hydroxycortisol (6beta-OHCOR) to cortisol (COR) in plasma as a biomarker to reflect CYP3A4 activity needs to be verified, but the low concentration of 6beta-OHCOR which is an endogenous substance in plasma presents a challenge for determination. Hydrocortisone 78-86 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 129-135 34092821-10 2021 The activity of CYP3A was evaluated using the HPLC-MS/MS method by the content of the endogenous substrate of the given isoenzyme and its metabolite in urine (6b-HC/cortisol). Hydrocortisone 162-164 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-21 34092821-10 2021 The activity of CYP3A was evaluated using the HPLC-MS/MS method by the content of the endogenous substrate of the given isoenzyme and its metabolite in urine (6b-HC/cortisol). Hydrocortisone 165-173 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-21 34633961-2 2021 This situation can be triggered by different causes including the use of CYP3A4-inducing drugs, which accelerate hydrocortisone clearance. Hydrocortisone 113-127 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 73-79 34633961-6 2021 Modafinil has the ability to induce the activity of CYP3A4 and consequently decrease the bioavailability of hydrocortisone. Hydrocortisone 108-122 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 52-58 34390638-6 2021 The activity of CYP3A4 isoenzyme was measured as the ratio of the concentrations of 6beta-hydroxycortisol and cortisol. Hydrocortisone 110-118 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-22 35589097-11 2022 The validated method was applied to evaluate the inhibitory effect of voriconazole to CYP3A by the ratio of 6beta-OHCOR to COR. Hydrocortisone 123-126 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 86-91 33622083-8 2021 CONCLUSION: Possible relationship between the CYP3A activity, evaluated by the content of the urinary endogenous substrate of the given isoenzyme and its metabolite, the 6-beta-hydroxy cortisol (6-beta-HC) / cortisol ratio, and the efficacy of diazepam was demonstrated. Hydrocortisone 185-193 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 46-51 32656158-4 2020 To specifically and quickly measure CYP3A activity, we developed method based on gas chromatography interfaced with triple-quadrupole mass spectrometry for the quantification of cortisol, cortisone, 6beta-hydroxycortisol, and 6beta-hydroxycortisone simultaneously in urine and 4beta-hydroxycholesterol in plasma. Hydrocortisone 178-186 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 36-41 33897064-10 2021 The activity of CYP3A was evaluated using the HPLC-MS/MS method by the content of the endogenous substrate of the given isoenzyme and its metabolite in urine (6b-HC/cortisol). Hydrocortisone 162-164 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-21 33897064-10 2021 The activity of CYP3A was evaluated using the HPLC-MS/MS method by the content of the endogenous substrate of the given isoenzyme and its metabolite in urine (6b-HC/cortisol). Hydrocortisone 165-173 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-21 32112986-4 2020 OBJECTIVE: The objective of our study was to investigate the effect of 99366316G>A polymorphism of the CYP3A4 gene on the concentration/dose indicator of alprazolam in patients with anxiety disorders comorbid with alcohol use disorder, using findings on enzymatic activity of CYP3A (as evaluated by the 6-beta-hydroxy-cortisol/cortisol ratio measurement) and on CYP3A4 expression level obtained by measuring the miR-27b plasma concentration levels in patients with anxiety disorders comorbid with alcoholism. Hydrocortisone 318-326 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 103-109 32112986-4 2020 OBJECTIVE: The objective of our study was to investigate the effect of 99366316G>A polymorphism of the CYP3A4 gene on the concentration/dose indicator of alprazolam in patients with anxiety disorders comorbid with alcohol use disorder, using findings on enzymatic activity of CYP3A (as evaluated by the 6-beta-hydroxy-cortisol/cortisol ratio measurement) and on CYP3A4 expression level obtained by measuring the miR-27b plasma concentration levels in patients with anxiety disorders comorbid with alcoholism. Hydrocortisone 318-326 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 103-108 32112986-10 2020 The activity of CYP3A was evaluated using the HPLC-MS/MS method by the content of the endogenous substrate of the given isoenzyme and its metabolite in urine (6- beta-hydroxy-cortisol/cortisol). Hydrocortisone 175-183 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-21 32112986-17 2020 In addition, we revealed the relationship between the CYP3A enzymatic activity (as evaluated by 6-beta-hydroxycortisol/ cortisol ratio measurement) and the miR-27b plasma concentration: rs = -0.27, p = 0.006. Hydrocortisone 110-118 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 54-59 31608377-9 2020 For cortisol metabolism indices, the following heritability was observed: for the A-ring reductases (5alpha-and 5beta-reductases), broad-sense heritability increased with age (to >50%), while for the other indices (renal 11beta-HSD2, global 11beta-HSD, and CYP3A4), the contribution of genetic factors was highest (68%, 18%, and 67%, respectively) at age 12. Hydrocortisone 4-12 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 257-263 31721244-3 2020 METHODS: A random forest (RF) algorithm which incorporated an endogenous CYP3A4 phenotype (assessed by urinary ratio of 6beta-hydroxycortisol and 6beta-hydroxycortisone to cortisol and cortisone), CYP3A5*3 genotype and other clinical determinants of tacrolimus disposition was performed in 182 medically stable renal transplant recipients. Hydrocortisone 133-141 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 73-79 32001245-1 2020 Hydroxylation activity at the 6beta-position of steroid hormones (testosterone, progesterone, and cortisol) by human cytochromes P450 (CYP) 3A4, polymorphic CYP3A5, and fetal CYP3A7 were compared to understand the catalytic properties of the major forms of human CYP3A subfamily. Hydrocortisone 98-106 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 117-143 32001245-2 2020 Testosterone, progesterone, and cortisol 6beta-hydroxylation activities of recombinant CYP3A4, CYP3A5, and CYP3A7 were determined by liquid chromatography. Hydrocortisone 32-40 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 87-93 30919109-10 2019 These data indicate that PXR plays a central role in cortisol-mediated induction of CYP3A activity during pregnancy and suggests that other enzymes and transporters, such as CYP2B6 and P-glycoprotein, may also be induced during pregnancy via the same mechanism(s). Hydrocortisone 53-61 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 84-89 31102151-3 2019 The activity of CYP3A4/5 was expressed as the ratio of the concentrations of cortisol and 6beta-hydroxycortisol was performed by using high performance liquid chromatography. Hydrocortisone 77-85 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-22 30683357-2 2019 We have shown that CYP3A4 substrate - hydrocortisone - and its 6beta-hydroxylated product have different emission wavelengths at an excitation lambdaex = 365 nm after treatment with sulfuric acid:ethanol (3:1) mixture (lambdaem = 525 +- 2 nm and lambdaem = 427 +- 2 nm, respectively). Hydrocortisone 38-52 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 19-25 30919109-4 2019 To determine the mechanism(s) by which cortisol induces CYP3A activity, HepaRG cells were pre-incubated in dexamethasone-free medium and then incubated for 72 h with cortisol (798 nM). Hydrocortisone 39-47 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 56-61 30919109-4 2019 To determine the mechanism(s) by which cortisol induces CYP3A activity, HepaRG cells were pre-incubated in dexamethasone-free medium and then incubated for 72 h with cortisol (798 nM). Hydrocortisone 166-174 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 56-61 30919109-6 2019 CYP3A4, and not CYP3A5, was found to be the dominant contributor to total CYP3A activity in control- and cortisol-treated HepaRG cells. Hydrocortisone 105-113 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-6 30919109-6 2019 CYP3A4, and not CYP3A5, was found to be the dominant contributor to total CYP3A activity in control- and cortisol-treated HepaRG cells. Hydrocortisone 105-113 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-5 30919109-8 2019 Cortisol-mediated CYP3A4 induction in HepaRG cells was primarily mediated by GR-dependent PXR induction pathway and to a smaller extent via a PXR-independent pathway. Hydrocortisone 0-8 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 18-24 31603853-7 2019 The quantification of the 6beta-OHC/cortisol metabolic ratio as a biomarker of CYP3A4 activity in human urine was used for the assessment of CYP3A4 catalytic activity as a non-invasive test. Hydrocortisone 36-44 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 79-85 31603853-13 2019 Results The ratio of 6-6beta-OHC/cortisol was used as a biomarker to study the taurine and L-carnitine influence on CYP3A4 metabolism of cortisol. Hydrocortisone 137-145 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 116-122 31603853-15 2019 Seven days after the administration of taurine in a dose of 500 mg twice a day, the 6beta-OCH/cortisol ratio was 3.3 +- 0.2, which indicated the increased catalytic activity of CYP3A4 towards cortisol. Hydrocortisone 94-102 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 177-183 31603853-15 2019 Seven days after the administration of taurine in a dose of 500 mg twice a day, the 6beta-OCH/cortisol ratio was 3.3 +- 0.2, which indicated the increased catalytic activity of CYP3A4 towards cortisol. Hydrocortisone 192-200 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 177-183 31603853-17 2019 Conclusions The results obtained demonstrated the influence of taurine on 6beta-OCH/cortisol metabolic ratio as a biomarker of CYP3A4 catalytic activity to cortisol. Hydrocortisone 84-92 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 127-133 31603853-17 2019 Conclusions The results obtained demonstrated the influence of taurine on 6beta-OCH/cortisol metabolic ratio as a biomarker of CYP3A4 catalytic activity to cortisol. Hydrocortisone 156-164 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 127-133 31581123-8 2019 The tuberculostatic drug rifampicin is a CYP3A4 inducer, increasing the metabolism of hydrocortisone. Hydrocortisone 86-100 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 41-47 31339834-2 2019 METHODS: Testosterone, progesterone, and cortisol 6beta-hydroxylation activities of recombinant CYP3A4 and CYP3A5 were determined by liquid chromatography. Hydrocortisone 41-49 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 96-102 31339834-1 2019 PURPOSE: Hydroxylation activity at the 6beta-position of steroid hormones (testosterone, progesterone, and cortisol) by human cytochromes P450 (P450 or CYP) 3A4 and CYP3A5 and their molecular docking energy values were compared to understand the catalytic properties of the major forms of human CYP3A, namely, CYP3A4 and CYP3A5. Hydrocortisone 107-115 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 165-170 31339834-1 2019 PURPOSE: Hydroxylation activity at the 6beta-position of steroid hormones (testosterone, progesterone, and cortisol) by human cytochromes P450 (P450 or CYP) 3A4 and CYP3A5 and their molecular docking energy values were compared to understand the catalytic properties of the major forms of human CYP3A, namely, CYP3A4 and CYP3A5. Hydrocortisone 107-115 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 310-316 28787271-7 2017 CYP2D6 and CYP3A were phenotyped with HPLC-MS using the concentration of endogenous substrate of the enzyme and its urinary metabolites [6-hydroxy-1,2,3,4-tetrahydro-beta-carboline(6-HO-THBC) to pinoline ratio for CYP2D6 and 6-beta-hydroxycortisol to cortisol ratio for CYP3A]. Hydrocortisone 239-247 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 11-16 29780235-5 2018 In clinical practice, the process of phenotyping of CYP isoenzymes and some endogenous substrates in the ratio of cortisol to 6beta-hydroxycortisol in urine for the evaluation of CYP3A4 activity has been deemed to be a quite promising, safe and minimally invasive method for patients nowadays. Hydrocortisone 114-122 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 179-185 29606886-10 2018 CYP3A isoenzyme group activity was evaluated by determining urinary concentration of endogenous substrate of the enzyme and its metabolite (6-beta-hydroxycortisol to cortisol ratio). Hydrocortisone 154-162 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-5 29343979-5 2018 The activity of CYP3A was evaluated by determining the concentrations of an endogenous substrate of this isoenzyme (cortisol) and its urinary metabolite (6-beta-hydroxycortisol, 6-B-HC). Hydrocortisone 116-124 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-21 30607725-1 2018 A method for determination of hydroxylase activity of cytochrome P450 3A4 (CYP3A4) towards its substrate hydrocortisone using fluorescent analysis of the product was developed. Hydrocortisone 105-119 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 54-73 30607725-1 2018 A method for determination of hydroxylase activity of cytochrome P450 3A4 (CYP3A4) towards its substrate hydrocortisone using fluorescent analysis of the product was developed. Hydrocortisone 105-119 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 75-81 30607725-2 2018 6beta-hydroxycortisol, formed during CYP3A4-dependent electrocatalysis, has a characteristic fluorescent peak at lambda = 427 +- 2 nm after treating with the sulfuric acid : ethanol (3 : 1) mixture and excitation at lambda = 365 nm, which is different from the substrate (hydrocortisone) fluorescence (lambda = 525 +- 2 nm). Hydrocortisone 272-286 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 37-43 30607725-4 2018 The developed analytical approach was used to determine the kinetic parameters of CYP3A4-dependent hydrocortisone hydroxylation. Hydrocortisone 99-113 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 82-88 29075133-3 2017 CYP3A4 isoenzyme activity was determined by urine cortisol and 6-beta-hydroxycortisol levels. Hydrocortisone 50-58 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-6 29075133-5 2017 RESULTS: Low mean 6-beta-hydroxycortisol/cortisol ratio is indicative of impaired CYP3A4 activity and was associated with higher risk of thrombosis (b coefficient=0.022, SE 0.009, p=0.021 in the linear regression model). Hydrocortisone 32-40 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 82-88 26924289-3 2016 The endogenous CYP3A4 phenotype was assessed by the ratio of 6beta-hydroxycortisol and 6beta-hydroxycortisone to cortisol and cortisone in urine. Hydrocortisone 74-82 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 15-21 28157069-7 2017 We monitored CYP2C9 and CYP3A activities over their clinical courses by measuring the metabolic clearance of S-warfarin to S-7-hydroxywarfarin and that of cortisol to 6beta-hydroxycortisol, respectively. Hydrocortisone 155-163 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 24-29 27511886-0 2016 Associations of the CYP3A5*3 and CYP3A4*1G polymorphisms with the pharmacokinetics of oral midazolam and the urinary 6beta-hydroxycortisol/cortisol ratio as markers of CYP3A activity in healthy male Chinese. Hydrocortisone 130-138 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 20-25 27317471-0 2016 Urinary 6beta-Hydroxycortisol/Cortisol Ratio Most Highly Correlates With Midazolam Clearance Under Hepatic CYP3A Inhibition and Induction in Females: A Pharmacometabolomics Approach. Hydrocortisone 30-38 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 107-112 27317471-7 2016 Of the urine and plasma metabolites measured, the 6beta-hydroxycortisol/cortisol ratio was most significantly correlated with midazolam clearance during hepatic CYP3A inhibition and induction. Hydrocortisone 63-71 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 161-166 27317471-8 2016 Our results suggest that the urinary 6beta-hydroxycortisol/cortisol ratio is the best predictor of hepatic CYP3A activity under both maximal inhibition and maximal induction. Hydrocortisone 50-58 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 107-112 27317471-9 2016 Furthermore, the predictive model including 6beta-hydroxycortisol/cortisol as a covariate could be applied to predict the magnitude of CYP3A-mediated drug interactions. Hydrocortisone 57-65 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 135-140 24611975-3 2014 The activity of CYP3A can be assessed by the urinary ratio of 6beta-hydroxycortisol to cortisol. Hydrocortisone 75-83 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 16-21 25678418-3 2015 6beta-Hydroxylation of many steroids, including cortisol, cortisone, progesterone and testosterone, was catalyzed primarily by CYP3A4. Hydrocortisone 48-56 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 127-133 25407158-2 2015 The urinary ratio of 6-beta hydroxycortisol to cortisol (6betaHF : F) is a marker of CYP3A4 induction. Hydrocortisone 35-43 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 85-91 26639694-14 2015 Determination of CYP3A4 activity was performed using high performance liquid chromatography with mass spectrometry (HPLC/ MS) by determination of endogenous substrate of this isoenzyme and its metabolite in urine - the ratio: cortisol/6-beta-hydroxycortisol. Hydrocortisone 226-234 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 17-23 26639694-31 2015 LIMITATIONS OF THE STUDY: It should be noted that in this research the activity of CYP3A4 was determined using high performance liquid chromatography with mass spectrometry (HPLC/MS) by determination the ratio of cortisol/6-beta-hydroxycortisol for the fist time. Hydrocortisone 213-221 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 83-89 24468605-1 2014 BACKGROUND: Antiepileptics may affect cortisol metabolism through CYP3A4. Hydrocortisone 38-46 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 66-72 23223499-2 2013 Placental growth hormone (PGH), estrogens (primarily 17beta-estradiol), cortisol, and progesterone have the potential to modulate CYP3A activity. Hydrocortisone 72-80 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 130-135 23223499-5 2013 Of all the hormones, cortisol was the most potent inducer of CYP3A activity and CYP3A4, CYP3A5 mRNA expression. Hydrocortisone 21-29 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 61-66 23223499-5 2013 Of all the hormones, cortisol was the most potent inducer of CYP3A activity and CYP3A4, CYP3A5 mRNA expression. Hydrocortisone 21-29 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 80-86 23223499-6 2013 The combination of PGH/growth hormone and cortisol induced CYP3A activity and expression significantly more than did cortisol alone. Hydrocortisone 42-50 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 59-64 23404385-16 2013 This is the first study to report the genetic polymorphism of CYP3A5 in a North Indian population and its association with urinary 6beta-OH-CS/CS ratio reflecting the CYP3A phenotypes. Hydrocortisone 140-142 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 62-67 23162091-7 2013 RESULTS: We found a sharp increase in the excretion of 6beta-hydroxycortisol over cortisol (P < 0.001), indicative of a strong induction of the major drug-metabolizing enzyme cytochrome P450 3A4. Hydrocortisone 68-76 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 178-197 23162091-12 2013 CONCLUSIONS: Cytochrome P450 3A4 induction by mitotane results in rapid inactivation of more than 50% of administered hydrocortisone, explaining the need for doubling hydrocortisone replacement in mitotane-treated patients. Hydrocortisone 118-132 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 13-32 23162091-12 2013 CONCLUSIONS: Cytochrome P450 3A4 induction by mitotane results in rapid inactivation of more than 50% of administered hydrocortisone, explaining the need for doubling hydrocortisone replacement in mitotane-treated patients. Hydrocortisone 167-181 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 13-32 22120734-6 2012 CYP3A4 enzyme activity in urine samples was assessed through determination of 6beta-hydroxycortisol/cortisol free ratio (6betaOHC/FC). Hydrocortisone 91-99 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 0-6 22253426-8 2012 Glucocorticoids, including dexamethasone, cortisol, corticosterone, and cortisone all induced the expression of CYP3A7 mRNA, whereas rifampicin, an activator of PXR and an inducer of CYP3A4 in adult liver, had no effect on CYP3A7 expression. Hydrocortisone 42-50 cytochrome P450 family 3 subfamily A member 4 Homo sapiens 183-189