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This study aimed to investigate the relationship between polymorphisms in the lipid metabolism-related gene PLA2G16 encoding Group XVI phospholipase A2 and the risk of colorectal cancer (CRC) in the Chinese population. A total of 185 patients with CRC and 313 healthy controls were enrolled. Thirteen single nucleotide polymorphisms (SNPs) of PLA2G16 were genotyped with SNPscan™. Linkage disequilibrium and haplotypes were analysed using Haploview software. Multivariate logistic regression was used to determine the association between the various genotypes and CRC risk. We identified five PLA2G16 SNPs (rs11600655, rs3809072, rs3809073, rs640908 and rs66475048) that were associated with CRC risk after adjusting for age, sex and body mass index. Two haplotypes (CTC and GGA) of rs11600655, rs3809073 and rs3809072, were relevant to CRC risk. The rs11600655 polymorphism was also associated with lymph node metastasis and CRC staging, while rs3809073 and rs3809072 may affect transcriptional regulation of PLA2G16 by altering transcription factor binding. These findings suggest that PLA2G16 polymorphisms-especially CTC and GGA haplotypes-increase CRC susceptibility. Importantly, we showed that the rs11600655 CC, rs640908 CT and rs66475048 GA genotypes are independent risk factors for CRC in the Chinese population.

Purpose: Itopride is an effective gastroprokinetic agent mainly used for the treatment of functional dyspepsia. Flavin-containing monooxygenase 3 (FMO3) has been confirmed to be the key enzyme involved in the main itopride metabolic pathway. We investigated whether the FMO3 genotypes can affect itopride metabolism in Chinese healthy volunteers., Methods: Twelve healthy volunteers who had been genotyped for FMO3 gene were selected to participate in our study. Volunteers were given 50 mg itopride orally and then blood samples were collected from 0 to 24 h. The plasma concentrations of itopride and itopride N-oxide were determined by HPLC-MS/MS method., Results: Itopride and itopride N-oxide both exhibit FMO3 genotype-dependent pharmacokinetic profiles. The area under the plasma concentration-time curve (AUC) of itopride increased by 127.82 ± 41.99 % (P < 0.001) and the AUC of itopride N-oxide decreased by 30.30 ± 25.70 % (P < 0.05) in homozygous FMO3 hhdd subjects (n = 6) compared with the HHDD group (n = 6). The CL/F value was lower in the hhdd group than that in the HHDD group (36.60 ± 7.06 vs. 80.20 ± 15.34 L/h, P < 0.001). But no significant differences in t1/2 value and tmax of itopride and itopride N-oxide were observed between these two genotypes., Conclusion: The FMO3 allele can significantly affect the metabolism of itopride. The pharmacokinetic parameters of both itopride and itopride N-oxide were significantly different between these two genotypes.

Purpose: As an inhibitor of HMG-CoA reductase that catalyses the first step of cholesterol synthesis, pitavastatin undergoes little hepatic metabolism; however, it is a substrate of uptake and efflux transporters. Since pitavastatin is potentially co-administered with agents that affect transporter activities, the pharmacokinetics of pitavastatin was investigated on the effects of a single-dose rifampin in healthy volunteers., Methods: Twelve Chinese healthy male volunteers took 4 mg pitavastatin orally with 150 ml water or with a single dose of 600 mg rifampin on separate occasions and the plasma concentrations of pitavastatin were measured over 48 h by HPLC-MS/MS., Results: A single dose of rifampin significantly increased the mean area under the plasma concentration-time curve(AUC)(0-48 h) and Cmax of pitavastatin by 573.5 %(95%CI, 373.3-773.7 %, p < 0.001) and 819.2 %(95 % CI, 515.4-1123.0 %, p < 0.001) respectively, while significantly decreased the t1/2 and CL/F of pitavastatin by 38.8 % (95 % CI, 18.2-59.4 %, p < 0.001) and 81.4 % (95 % CI, 75.0-87.7 %, p < 0.001) respectively., Conclusions: Co-administration of pitavastatin with a single dose of rifampin resulted in a significant increase in plasma levels of pitavastatin in Chinese healthy subjects.

Purpose: ORM1 is a plasma drug binding protein. Its polymorphism rs17650 (S>F) has been reported to be an important factor affecting the binding ability and effect of antiretroviral protease inhibitors. The aim of this study was to determine whether the ORM1 rs17650 polymorphism also influences warfarin therapy., Methods: A total of 191 Chinese patients with steady-dose warfarin therapy were enrolled in this study. The patients were studied for warfarin maintenance dose, the ORM1 rs17650 polymorphism, and two polymorphisms previously demonstrated to affect warfarin response [CYP2C9 rs1057910 (3) and VKORC1 rs7294 (-1639 G>A)]., Results: Warfarin dose was partially correlated with the VKORC1 rs7294, CYP2C9 rs1057910 and ORM1 rs17650 polymorphisms. Patients carrying the wild-type of these three genes (n = 96) took a mean dose of 3.0 ± 1.1 mg warfarin, which was significantly higher than that taken by the 52 S patients (2.7 ± 0.7) and 11 S S patients (2.5 ± 0.6 mg) (p = 0.048)., Conclusion: We identified ORM1 as another polymorphic gene affecting warfarin dose requirements. ORM1 S carriers require lower maintenance doses to achieve and maintain an optimal level of anticoagulation.

Purpose: To explore the impact of UDP-glucuronosyltransferase polymorphisms (UGT1A9-118(dT) 9/10 , UGT1A9 CI399T, UGT1A9 C-440T and UGT2B7 G211T) on the pharmacokinetics of mycophenolic acid (MPA) in healthy Chinese volunteers., Methods: We recruited ten healthy volunteers with no polymorphisms (control group), 11 homozygotes of mutants UGT1A9 CI399T and UGT1A9-118(dT) 9/10 , ten heterozygotes of UGT1A9 C440T and seven carriers of UGT2B7 211T from a total of 518 healthy Chinese volunteers. All the volunteers were orally administered a single dose of 1.5 g mycophenolate mofetil (MMF) after an overnight fast. Plasma was then collected 72 h after MMF administration. MPA, MPA-7-O-glucuronide (MPAG) and its acylglucuronide (AcMPAG) were detected by ultra-pressure liquid chromatography with UV detection., Results: Compared with the control group, the UGT1A9 CI399T and UGT1A9-118(dT) 9/10 mutant homozygotes had higher MPAG plasma concentrations. Subjects with UGT1A9-440TC had enhanced MPA exposure while carriers of UGT2B7 211T had higher concentrations of the toxic metabolite, AcMPAG., Conclusions: The current results indicate that UGT1A9 and UGT2B7 genotypes could significantly alter MPA pharmacokinetics in healthy Chinese volunteers after a single oral dose of MMF.

Purpose: Berberine is a plant alkaloid that is widely used to treat gastrointestinal infections, diabetes, hypertension, and hypercholesterolemia. Many studies have reported interactions between berberine-containing products and cytochromes P450 (CYPs), but little is known about whether berberine alters CYP activities in humans, especially after repeated doses., Methods: A two-phase randomized-crossover clinical study in healthy male subjects was performed. After 2 weeks of berberine (300 mg, t.i.d., p.o.) administration, midazolam, omeprazole, dextromethorphan, losartan, and caffeine were used to evaluate enzyme activities of CYP3A4, 2C19, 2D6, 2C9, and CYP1A2, respectively., Results: A decrease in CYP2D6 activity was observed as the 0-8 h urinary dextromethorphan/dextrorphan increased ninefold (P < 0.01). In addition, losartan/E-3174 ratio doubled (P < 0.01) after BBR administration, indicating a decrease in CYP2C9 activity. CYP3A4 activity was also inhibited, as the C(max), AUC(0-∞), and AUC(0-12) of midazolam were increased 38% (P < 0.05), 40% (P < 0.01), and 37% (P < 0.05) after BBR treatment, respectively. Compared with the placebo period, the T(max) and T(1/2) of midazolam during BBR administration were prolonged from 3.03 ± 0.27 to 3.66 ± 0.37 h and 0.66 ± 0.08 to 0.99 ± 0.09 h, respectively; the oral clearance of midazolam was decreased 27% (P < 0.05); and the phenotypic indices of 1 h midazolam/1'-hydroxymidazolam increased 59% (P < 0.01). There were no statistically significant differences in the pharmacokinetic parameters of the other probe drugs between placebo and the BBR-treated group., Conclusions: Repeated administration of berberine (300 mg, t.i.d., p.o.) decreased CYP2D6, 2C9, and CYP3A4 activities. Drug-drug interactions should be considered when berberine is administered.

Purpose: This study investigated the effect of 1 g genistein daily for 14 days on caffeine-based metrics of cytochrome P4501A2 (CYP1A2), cytochrome P4502A6 (CYP2A6), N-acetyltransferase 2 (NAT2), and xanthine oxidase (XO)., Methods: A single dose of 100 mg caffeine was administered once before and once on the last day of a 14-day treatment regime with 1 g genistein once daily to 18 healthy female volunteers. Urine and blood samples were collected up to 12 and 24 h, respectively, after each caffeine dose. Using high-performance liquid chromatography (HPLC), caffeine and 1,7-dimethylxanthine (17X) were quantified in plasma, whereas 17X, 1,7-dimethylurate (17U), 1-methylxanthine (1X), 1-methylurate (1U), and 5-acetylamino-6-formylamine-3-methyluracil (AFMU) were quantified in urine. Urinary metabolite ratios were calculated to assess enzyme activities and compared between administrations using analysis of variance (ANOVA)., Results: Genistein decreased the urinary caffeine metabolite ratio used to assess CYP1A2 activity by 41% [90% confidence interval (CI) 28-51%). The urinary ratio indicating XO activity decreased by 29% (90% CI 24-32%), whereas urinary ratio for CYP2A6 activity increased by 47% (90% CI 29-66%) after 2 weeks of genistein. The NAT2 urinary caffeine metabolite ratio did not change significantly., Conclusions: Two weeks of intake of 1 g genistein daily led to decreases in CYP1A2 and XO activity and an increase in CYP2A6 activity, whereas NAT2 activity did not change in healthy Chinese female volunteers. Pharmacokinetics of other substrates of the enzymes investigated here may be influenced in a similar manner.

Purpose: To assess the impacts of erythromycin on the pharmacokinetics of voriconazole and its association with CYP2C19 genotypes in healthy Chinese male subjects., Methods: A single-center, open, crossover clinical study with two treatment phases was carried out. Eighteen healthy male volunteers, including 6 CYP2C19 homozygous extensive metabolizers (EMs, *1/*1), 6 heterozygous EMs (HEMs, *1/*2 or *1/*3), and 6 CYP2C19 poor metabolizers (PMs, *2/*2 or *2/*3), were enrolled in this study. A single oral dose of 200 mg voriconazole was administrated to all subjects after 3-day pretreatment with either 500 mg erythromycin or placebo three times daily. Periods were separated by a washout period of 14 days. Serial venous blood samples were collected, and plasma concentrations of voriconazole were determined by HPLC., Results: C(max), AUC(0-24), and AUC(0-infinity) of voriconazole were increased significantly, while oral clearance of voriconazole was decreased significantly by erythromycin administration (p < 0.001, respectively). Compared with individuals with CYP2C19 PM genotypes, individuals with CYP2C19 EM and HEM genotypes showed significantly decreased T(½), AUC(0-24), AUC(0-infinity), and increased oral clearance of voriconazole (p < 0.05, respectively). In addition, significant increases in AUC(0-24) and AUC(0-infinity) and decreases in oral clearance of voriconazole after erythromycin treatment were observed in CYP2C19 HEMs and PMs (p < 0.05, respectively), but not in CYP2C19 EMs., Conclusion: Both CYP2C19 genotypes and CYP3A4 inhibitor erythromycin can influence the plasma concentration of voriconazole, and erythromycin increases plasma concentration of voriconazole in a CYP2C19 genotype-dependent manner.

Background: Glycyrrhizin is a major ingredient of licorice which is widely used in the treatment of various diseases such as chronic hepatitis. Licorice or glycyrrhizin has been shown to alter the activity of CYP3A in rodents. The influence of glycyrrhizin on CYP3A has not been elucidated in humans., Objective: To investigate the effects of repeated glycyrrhizin ingestion on the oral pharmacokinetics of midazolam, a probe drug for CYP3A activity in humans., Methods: Sixteen healthy adult male subjects were enrolled in a two-phase randomized crossover design. In each phase the volunteers received placebo or glycyrrhizin for 14 days. On the 15th day, midazolam was administered and blood samples were obtained to determine midazolam plasma concentrations. Bioequivalence was assessed by determining geometric mean ratios (GMRs) and 90% confidence intervals (90% CI)., Results: The geometric mean (geometric coefficient of variation) for the AUC(0-infinity) of midazolam in the placebo group was 196.4 ng x h/ml (30.3%) and after glycyrrhizin treatment, 151.3 ng x h/ml (34.7%). The GMRs and 90% CI for AUC(0-infinity) and Cmax of midazolam in the presence/ absence of glycyrrhizin were 0.77 (0.70, 0.89) and 0.83 (0.74, 1.01), respectively. The 90% CI for AUC(0-infinity) and Cmax for the GMR of glycyrrhizin over placebo were both out of the no-effect boundaries of 0.80-1.25., Conclusions: Administration of glycyrrhizin resulted in a modest induction of CYP3A that was clinically relevant according to the bioequivalence analysis.

Purpose: To investigate the effects of silymarin on the pharmacokinetics of losartan and its active metabolite E-3174 and its relationship with CYP2C9 genotypes., Methods: Twelve healthy adult men of known CYP2C9 genotype (six CYP2C9*1/*1 and six CYP2C9*1/*3) were recruited in a two-phase randomized crossover design study. The pharmacokinetics of losartan and E-3174 were measured before and after a 14-day treatment with 140 mg of silymarin three times daily., Results: The area under the plasma concentration-time curve (AUC) of losartan increased significantly following a 14-day silymarin treatment in subjects with the CYP2C9*1/*1 genotype, but not in those with the CYP2C9*1/*3 genotype. The AUC of E-3174 decreased significantly with a silymarin pretreatment in both CYP2C9*1/*1 and the CYP2C9*1/*3 subjects. The metabolic ratio of losartan (ratio of AUC(0-infinity) of E-3174 to AUC(0-infinity) of losartan) decreased significantly after a 14-day treatment with silymarin in individuals with the CYP2C9*1/*1 genotype (p < 0.05), but not in those with the CYP2C9*1/*3 genotype (p = 0.065)., Conclusion: Silymarin inhibits the metabolism of losartan to E-3174, with the magnitude of the interaction differing in individuals with different CYP2C9 genotypes.

Objective: To investigate the interaction between allicin and omeprazole and to observe the effects of allicin on CYP2C19 and CYP3A4 activity in healthy Chinese male volunteers with different CYP2C19 genotypes., Methods: Eighteen subjects (six CYP2C19*1/CYP2C19*1, four CYP2C19*1/CYP2C19*2, two CYP2C19*1/ CYP2C19*3, and six CYP2C19*2/ CYP2C19*2) were enrolled in a two-phase randomized crossover trial. In each phase, all subjects received placebo or a 180 mg allicin capsule once daily for 14 consecutive days. The pharmacokinetics of omeprazole (20 mg orally on day 15) was determined for up to 12 h following administration by high-performance liquid chromatography., Results: In carriers of the CYP2C19*1/CYP2C19*1 and CYP2C19*1/CYP2C19*2 or *3 genotype, allicin treatment increased the peak plasma concentration (C(max)) of omeprazole by 49.7 +/- 7.2 (p < 0.001) and 54.2 +/- 9.2% (p < 0.001), and increased the area under the plasma time-concentration curve (AUC(0-infinity)) of omeprazole by 48.1 +/- 9.0 (p = 0.001) and 73.6 +/- 26.7% (p < 0.001), respectively. The ratio of AUC(0-infinity) of 5-hydroxyomeprazole to omeprazole (a marker for CYP2C19 activity) decreased significantly (p < 0.001 and p = 0.001, respectively). However, no pharmacokinetic parameters were significantly changed by allicin in CYP2C19*2/CYP2C19*2. The C(max) and AUC(0-infinity) of omeprazole sulfone were unchanged in all three genotypes., Conclusions: Allicin reduced the metabolism of omeprazole by inhibiting CYP2C19 activity in individuals with the CYP2C19*1/CYP2C19*1 and CYP2C19*1/CYP2C19*2 or *3 genotypes, but not in those with the CYP2C19*2/ CYP2C19*2 genotype. Allicin did not significantly affect the activity of CYP3A4 in all subjects.

Purpose: This study investigated the effect of the herbal medicine baicalin on bupropion hydroxylation, a probe reaction for CYP2B6 activity related to different CYP2B6 genotype groups., Method: Seventeen healthy male volunteers (6 CYP2B6*1/*1, 6 CYP2B6*1/*6, and 5 CYP2B6*6/*6) received orally administered bupropion alone and during daily treatment with baicalin. Blood samples were taken up to 72 h after each bupropion dose, and pharmacokinetics profiles were determined on days 1 and 25 for bupropion and hydroxybupropion., Result: Baicalin administration increased hydroxybupropion maximum plasma concentration (C(max)) by 73% [90% confidence interval (CI), 44-108%; P < 0.01] and the area under the concentration time curve extrapolated to infinity (AUC(0-infinity)) of hydroxybupropion by 87% (90% CI, 48-137%; P < 0.01), with no change in the elimination half-life of hydroxybupropion. Baicalin increased the AUC(0-infinity) ratio of hydroxybupropion to bupropion by 63% (90% CI, 38-92%; P < 0.01)., Conclusion: Baicalin significantly induced CYP2B6-catalyzed bupropion hydroxylation, and the effects of baicalin on other CYP2B6 substrate drugs deserve further investigation.

Aim: To study the pharmacokinetic characteristics of voriconazole in healthy Chinese male volunteers in relation to cytochrome P450 (CYP) 2C19 genotype status, including ultra-rapid metabolizers (URMs), homozygous extensive metabolizers (EMs), and poor metabolizers (PMs)., Method: Twenty healthy Chinese male volunteers were recruited for the study. Of these, four were CYP2C19 heterozygous URMs (*1/*17), eight were CYP2C19 homozygous EMs (*1/*1), and eight were CYP2C19 PMs (*2/*2). After a single oral dose of 200 mg voriconazole, plasma concentrations of voriconazole were determined for a 24-h period by liquid chromatography-mass spectrometry/mass spectrometry., Result: In Chinese male subjects, the allele frequencies of the CYP2C19*17 and CYP2C19*2 alleles were 0.64 and 35.6%, respectively, and both alleles were in Hardy-Weinberg equilibrium. The area under the concentration-time curve (AUC) from predose to 24 h (AUC(0-24)) and from predose to infinity (AUC(0-infinity)), and apparent oral clearance (CL/F) of voriconazole were statistically different among all three genotypic groups (P < 0.001, respectively). The maximum plasma concentration (C(max)) value of URMs also showed statistically significant differences from those of EMs and PMs (P = 0.036 and P = 0.035, respectively). The elimination half-life (t(1/2)) in URMs was 87% (P = 0.58) of that in EMs and 51% (P= 0.002) of that in PMs., Conclusion: Our data indicate that the presence of the CYP2C19*17 allele results in ultra-rapid metabolism of voriconazole after a single oral dose.

Objectives: To determine the frequencies of CYP3A4 alleles (CYP3A4*4,*5 and *6) in Chinese hyperlipidemic patients and to observe the impact of CYP3A4*4 (Ile118Val) genetic polymorphism on the lipid-lowering effects of simvastatin and on the activity of CYP3A4., Methods: From hospitalized and non-hospitalized patients, 211 unrelated hyperlipidemic patients were recruited for genotyping. CYP3A4 genotypes were determined by means of polymerase chain reaction and restriction fragment length polymorphism analysis. Of the non-hospitalized hyperlipidemic patients, 8 with CYP3A4*1/*1 and 8 with CYP3A4*1/*4 genotypes were selected to be treated with 20 mg simvastatin daily for 4 weeks. Serum triglycerides (TG), cholesterol (CHO) and low-density lipoprotein (LDL) levels were determined using an automated analyzer (Hitachi 747, Boehringer Mannheim, Mannheim, Germany). 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., Results: Of 211 subjects, 14 (allele frequency 3.32%) were heterozygous for CYP3A4*4 (Ile118Val). Nevertheless, no subjects with a CYP3A4*5 or CYP3A4*6 allele or homozygous for CYP3A4*4 were identified. The ratio of 6beta-OHC/FC was 9.9 +/- 13.7 and 56.6 +/- 35.7 in subjects with the Ile118Val variant (n = 8) and in CYP3A4 wild-type subjects (n = 8), respectively (P = 0.0039). After oral intake of simvastatin 20 mg daily for 4 weeks, the change of serum lipids in CYP3A4*1/*1 and CYP3A4*1/*4 groups showed a significant difference, with a mean decrease in triglycerides and total cholesterol of 38.1 +/- 7.6% versus 25.1 +/- 8.3% (P = 0.034) and of 35.8 +/- 9.6% versus 22.0 +/-20.4% (P = 0.0015) (means +/- SD), respectively. We found no statistically significant difference in the reductions of LDL between subjects carrying the *1 and *4 genotypes (29.0 +/- 7.4% versus 36.8 +/- 8.8%, P = 0.0721)., Conclusions: The allele frequency of CYP3A4*4 was 3.32% among the hyperlipidemic patients from the Chinese mainland. CYP3A4*4 was an allelic variant related to a functional decrease of CYP3A4 activity, and *4 expression seemed to increase the lipid-lowering effects of simvastatin.