MASS SPECTROMETRY-BASED PERSONALIZED DRUG THERAPY.

Personalized drug therapy aims to provide tailored treatment for individual patient. Mass spectrometry (MS) is revolutionarily involved in this area because MS is a rapid, customizable, cost-effective, and easy to be used high-throughput method with high sensitivity, specificity, and accuracy. It is driving the formation of a new field, MS-based personalized drug therapy, which currently mainly includes five subfields: therapeutic drug monitoring (TDM), pharmacogenomics (PGx), pharmacomicrobiomics, pharmacoepigenomics, and immunopeptidomics. Gas chromatography-MS (GC-MS) and liquid chromatography-MS (LC-MS) are considered as the gold standard for TDM, which can be used to optimize drug dosage. Matrix-assisted laser desorption ionization-time of flight-MS (MALDI-TOF-MS) significantly improves the capability of detecting biomacromolecule, and largely promotes the application of MS in PGx. It is becoming an indispensable tool for genotyping, which is used to discover and validate genetic biomarkers. In addition, MALDI-TOF-MS also plays important roles in identity of human microbiome whose diversity can explain interindividual differences of drug response. Pharmacoepigenetics is to study the role of epigenetic factors in individualized drug treatment. MS can be used to discover and validate pharmacoepigenetic markers (DNA methylation, histone modification, and noncoding RNA). For the emerging cancer immunotherapy, personalized cancer vaccine has effective immunotherapeutic activity in the clinic. MS-based immunopeptidomics can effectively discover and screen neoantigens. This article systematically reviewed MS-based personalized drug therapy in the above mentioned five subfields. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.

Relationship between polymorphisms of the lipid metabolism-related gene PLA2G16 and risk of colorectal cancer in the Chinese population.

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.

Comparative pharmacokinetic study on three formulations of Astragali Radix by an LC-MS/MS method for determination of formononetin in human plasma.

Astragali Radix (AR) is a widely used traditional Chinese medicine for healing the cardiovascular, liver and immune systems. Recently, superfine pulverizing technology has been applied to developing novel formulations to improve bioavailability of the active constituents in herbs, such as ultrafine granular powder of AR. In this study, a universal and sensitive quantitative method based on LC-MS/MS was employed for determining formononetin, the main flavonoid in AR, in human plasma for comparative pharmacokinetics of three oral formulations of AR. Formononetin and IS (quercetin) were extracted by ethyl acetate from human plasma and were separated on a C18 column with a mobile phase consisting of acetonitrile and 0.1% formic acid. Positive-ion electrospray-ionization mode was applied in mass spectrometric detection. The quantitative method was validated with regards to selectivity, linearity, accuracy and precision, matrix effect, extraction recovery and stability, and was applied to comparing the pharmacokinetics of ultrafine granular powder (UGP), ultrafine powder (UP) and traditional decoction pieces (TDP) of AR after oral administration. The peak concentration and areas under the concentration-time curve of formononetin in UGP and UP were significantly higher than those of TDP. UGP and UP could significantly improve the bioavailability of AR in human compared with TDP after oral administration.

The potent mechanism-based inactivation of CYP2D6 and CYP3A4 with fusidic acid in in vivo bioaccumulation.

1. The accumulation of fusidic acid (FA) after multiple doses of FA has been reported on in previous studies but the related mechanisms have not been clarified fully. In the present study, we explain the mechanisms related to the mechanism-based inactivation of CYP2D6 and CYP3A4. 2. The irreversible inhibitory effects of FA on CYP2D6 and CYP3A4 were examined via a series of experiments, including: (a) time-, concentration- and NADPH-dependent inactivation, (b) substrate protection in enzyme inactivation and (c) partition ratio with recombinant human CYP enzymes. Metoprolol α-hydroxylation and midazolam 1'-hydroxylation were used as marker reactions for CYP2D6 and CYP3A4 activities, and HPLC-MS/MS measurement was also utilised. 3. FA caused to the time- and concentration-dependent inactivation of CYP2D6 and CYP3A4. About 55.8% of the activity of CYP2D6 and 75.8% of the activity of CYP3A4 were suppressed after incubation with 10 µM FA for 15 min. KI and kinact were found to be 2.87 µM and 0.033 min-1, respectively, for CYP2D6, while they were 1.95 µM and 0.029 min-1, respectively, for CYP3A4. Inhibition of CYP2D6 and CYP3A4 activity was found to require the presence of NADPH. Substrates of CYP2D6 and CYP3A4 showed that the enzymes were protected against the inactivation induced by FA. The estimated partition ratio for the inactivation was 7 for CYP2D6 and 12 for CYP3A4. 4. FA is a potent mechanism-based inhibitor of CYP2D6 and CYP3A4, which may explain the accumulation of FA in vivo.

Effects of quercetin on pharmacokinetics of cefprozil in Chinese-Han male volunteers.

1. The primary objective of this study was to evaluate the effects of quercetin on the pharmacokinetics of cefprozil. The secondary objective was to evaluate the safety of the combined use of cefprozil and quercetin. 2. An open-label, two-period, crossover phase I trial among 24 Han Chinese male subjects was conducted. Participants were given 500 mg of quercetin orally once daily for 15 d followed by single dose of cefprozil (500 mg) on day 15. Serum concentrations of cefprozil were then measured in all participants on day 15. A 15-d washout period was then assigned after which a 500 mg dose of cefprozil was administered and measured in the serum on day 36. 3. All subjects completed the trial, and no serious adverse events were reported. We measured mean serum concentrations of cefprozil in the presence and absence of quercetin in all participants. The maximum serum concentration of cefprozil in the presence of quercetin was 8.18 ug/ml (95% CI: 7.55-8.81) versus a maximum cefprozil concentration of 8.35 ug/ml (95% CI: 7.51-9.19) in the absence of quercetin. We conclude that the concurrent use of quercetin has no substantial effect on serum concentrations of orally administered cefprozil. 4. Co-administration of quercetin showed no statistically significant effects on the pharmacokinetics of cefprozil in healthy Chinese subjects.

Effect of two-linked mutations of the FMO3 gene on itopride metabolism in Chinese healthy volunteers.

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.

A high-throughput inhibition screening of major human cytochrome P450 enzymes using an in vitro cocktail and liquid chromatography-tandem mass spectrometry.

A sensitive and high-throughput inhibition screening liquid chromatography-mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous quantification of five probe metabolites (7-hydroxycoumarin, CYP2A6; 4-hydroxytolbutamide, CYP2C9; 4'-hydroxymephenytoin, CYP2C19; α-hydroxymetoprolol, CYP2D6; and 1-hydroxymidazolam, CYP3A4) for in vitro cytochrome P450 activity determination in human liver microsome and recombinant. All the metabolites and the internal standard, tramadol, were separated on a Waters 2695 series liquid chromatograph with a Phenomenex Luna C18 column (150 × 2.0 mm, 5 µm). Quality control samples and a positive control CYP inhibitor were included in the method. The IC50 values determined for typical CYP inhibitors were reproducible and in agreement with the literature. The method was selective and showed good accuracy (99.13-103.37%), and inter-day (RSD < 6.20%) and intra-day (RSD < 6.13%) precision. Also, the incubation extracts of the sample were stable at room temperature (20 °C) for 48 h and for 96 h in the autosampler (4 °C). The presented method is the first HPLC-MS/MS method of this combination for simultaneous detection of the five metabolites 7-hydroxycoumarin, 4-hydroxytolbutamide, 4'-hydroxymephenytoin, α-hydroxymetoprolol and 1-hydroxymidazolam in a single-run process. It is possible that the high-quality and -throughput cocktail provides suitable information in drug discovery and screening for new drug entities.

Validation of a liquid chromatography-electrospray ionization-tandem mass spectrometry method for determination of all-trans retinoic acid in human plasma and its application to a bioequivalence study.

A sensitive, reliable and specific LC-MS-MS method was developed and validated for the identification and quantitation of all-trans retinoic acid (ATRA) in human plasma. Acitretin was used as the internal standard (IS). After liquid-liquid extraction of 500 µL plasma with methyl tert-butyl ether (MTBE), ATRA and the IS were chromatographed on a HyPURITY C18 column (150 mm×2.1 mm, 5 µm) with the column temperature set at 40 °C. The mobile phase was consisted of 40% phase A (MTBE-methanol-acetic acid, 50:50:0.5, v/v) and 60% phase B (water-methanol-acetic acid, 50:50:0.5, v/v) with a flow rate of 0.3 mL/min. The API 4000 triple quadrupole mass spectrometer was operated in multiple reaction monitoring (MRM) mode via the positive electrospray ionization interface using the transition m/z 301.4→123.1 for ATRA and m/z 326.9→177.1 for IS, respectively. The calibration curve was linear over the range of 0.45-217.00 ng/mL (r≥0.999) with a lower limit of quantitation (LLOQ) of 0.45 ng/mL. The intra- and inter-day precisions values were below 8% relative standard deviation and the accuracy was from 98.98% to 106.19% in terms of relative error. The validated method was successfully applied in a bioequivalence study of ATRA in Chinese healthy volunteers.

The effect of Na+/taurocholate cotransporting polypeptide (NTCP) c.800C > T polymorphism on rosuvastatin pharmacokinetics in Chinese healthy males.

This study was designed to investigate the potential association between NTCP c.800C >T polymorphism and rosuvastatin pharmacokinetics in Chinese healthy males. 305 individuals were enrolled to identify NTCP c.800C > T, OATP1B1 c.521T > C and BCRP c.421C > A genotypes by direct sequencing and pyrosequencing methods, respectively. 17 healthy volunteers who were OATP1B1 c.521TT and BCRP c.421CC wild-type homozygotes with different NTCP c.800C > T genotype were selected to participate in this pharmacokinetic study. Nine were NTCP c.800CC wild-type homozygotes and the other eight subjects were carriers with at least one c.800T variant allele (seven subjects with c.800CT genotype and one was homozygote of c.800TT). All the subjects received a single oral dose of 10 mg rosuvastatin. The plasma concentrations of rosuvastatin were measured up to 72 h by a LC-MS method. NTCP c.800C > T genetic polymorphism markedly effected rosuvastatin pharmacokinetics. The AUC(o-72) and AUC(0 --> ∞) in subjects with NTCP c.800CT + TT genotype were 56% (162.64 ± 37.55 vs. 103.99 ± 28.15 ng x h/ml, P = 0.016) and 57% greater (178.51 ± 42.75 vs. 113.60 ± 33.73 ng x h/ml, P = 0.020) than those in the c.800CC wild-type subjects, respectively. In the c.800CT + TT mutant group, the C(max) was about 78% higher than those in c.800CC genotype (14.31 ± 3.63 vs. 8.04 ± 1.72 ng x h/ml, P = 0.004). The oral clearance (CL/F) of rosuvastatin in subjects with the c.800CT+TT genotype was only 63% of those in the c.800CC genotype (58.32 ± 12.16 vs. 93.04 ± 20.61 ng x h/ml, P = 0.009). The half-time (T1/2) and the T(max) had no significant difference between two groups (p = 0.466 and 0.713, respectively). NTCP c.800C > T polymorphism play a critical role in the individual variability of rosuvastatin pharmacokinetics in Chinese healthy males after excluding the impact of OATP1B1 c.521T > C and BCRP c.421C > A polymorphisms.

Polymorphisms of UGT1A9 and UGT2B7 influence the pharmacokinetics of mycophenolic acid after a single oral dose in healthy Chinese volunteers.

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.

Effect of a single-dose rifampin on the pharmacokinetics of pitavastatin in healthy volunteers.

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.

Influence of ORM1 polymorphisms on the maintenance stable warfarin dosage.

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.

Assessment of a pharmacokinetic and pharmacodynamic interaction between simvastatin and Ginkgo biloba extracts in healthy subjects.

1. Ginkgo biloba extract (GBE) is one of the most commonly used herbal remedies worldwide. It is usually concomitantly administrated with statins to treat diseases in geriatric patients. We aim to determine the influence of GBE on the pharmacokinetics (PK) and pharmacodynamics of simvastatin, which is currently unknown. 2. An open-label, randomized, two-period, two-treatment, balanced, crossover study was performed in 14 healthy volunteers. Subjects received simvastatin 40 mg once daily, co-treated with placebo or GBE 120 mg twice daily. Each treatment was administered for 14 d, separated by a wash-out period of 1 month. Simvastatin, simvastatin acid and lipoprotein concentrations were assessed. 3. GBE administration reduced mean simvastatin area under the curve (AUC)0-24, AUC0-∞ and Cmax by 39% (p = 0.000), 36%(p = 0.001) and 32% (p = 0.002), respectively, but did not cause significant differences in simvastatin acid PK or its cholesterol-lowering efficacy. 4. GBE consumption decreased simvastatin system exposure, but did not affect simvastatin acid PK. However, we cannot rule out the possibility for a pharmacodynamic interaction between GBE and simvastatin in vivo.

Effect of pitavastatin in different SLCO1B1 backgrounds on repaglinide pharmacokinetics and pharmacodynamics in healthy Chinese males.

The effect of pitavastatin and SLCO1B1 genetic background on the pharmacokinetic and pharmacodynamic properties of repaglinide was investigated. In this randomized, placebo-controlled, crossover study, twelve healthy Chinese males were administered with pitavastatin 4 mg/d or the placebo for 5 d followed by repaglinide 4 mg given orally on d 5. Plasma repaglinide and glucose levels were measured by liquid chromatography-tandem mass spectrometry (LC/MS/MS) and the glucose oxidase method, respectively. Treatment with pitavastatin significantly increased the peak plasma concentration (Cmax) of repaglinide (P=0.003) in SLCO1B1*1b homozygotes (P=0.015) and SLCO1B1*15 carriers (P=0.031). Treatment with pitavastatin led to a marginal increase in the area under plasma concentration-time curve from 0 h to infinity (AUC0⇒∞) of repaglinide (P=0.091). There was no significant difference in pharmacokinetic parameters or hypoglycemic effects of repaglinide among SLCO1B1 genotypes in either the pitavastatin or control group. Pitavastatin increased the Cmax of the plasma concentration of repaglinide in an SLCO1B1 genotype dependent manner, but had no apparent effect on the pharmacodynamics of repaglinide in healthy volunteers. The p values for this statement were not reported.

Inhibition of the organic anion-transporting polypeptide 1B1 by quercetin: an in vitro and in vivo assessment.

AIM: To investigate the effect of quercetin on organic anion transporting polypeptide 1B1 (OATP1B1) activities in vitro and on the pharmacokinetics of pravastatin, a typical substrate for OATP1B1 in healthy Chinese-Han male subjects. METHODS: Using human embryonic kidney 293 (HEK293) cells stably expressing OATP1B1, we observed the effect of quercetin on OATP1B1-mediated uptake of estrone-3-sulphate (E3S) and pravastatin. The influence of quercetin on the pharmacokinetics of pravastatin was measured in 16 healthy Chinese-Han male volunteers receiving a single dose of pravastatin (40 mg orally) after co-administration of placebo or 500 mg quercetin capsules (once daily orally for 14 days). RESULTS: Quercetin competitively inhibited OATP1B1-mediated E3S uptake with a K(i) value of 17.9 ± 4.6 µm and also inhibited OATP1B1-mediated pravastatin uptake in a concentration dependent manner (IC(50) , 15.9 ± 1.4 µm). In healthy Chinese-Han male subjects, quercetin increased the pravastatin area under the plasma concentration - time curve (AUC(0,10 h) and the peak plasma drug concentration (C(max)) to 24% (95% CI 15, 32%, P < 0.001) and 31% (95% CI 20, 42%, P < 0.001), respectively. After administration of quercetin, the elimination half-life (t(1/2) ) of pravastatin was prolonged by 14% (95% CI 4, 24%, P = 0.027), with no change in the time to reach C(max) (t(max) ). Moreover, quercetin decreased the apparent clearance (CL/F) of pravastatin by 18% (95% CI 75, 89%, P < 0.001). CONCLUSIONS: These findings suggest that quercetin inhibits the OATP1B1-mediated transport of E3S and pravastatin in vitro and also has a modest inhibitory influence on the pharmacokinetics of pravastatin in healthy Chinese-Han male volunteers. The effects of quercetin on other OATP1B1 substrate drugs deserve further investigation.

Rapid clinical induction of bupropion hydroxylation by metamizole in healthy Chinese men.

AIMS: This study aimed to investigate the effect of metamizole on bupropion hydroxylation related to different CYP2B6 genotype groups in healthy volunteers. METHODS: Sixteen healthy male volunteers (6 CYP2B6*1/*1, 6 CYP2B6*1/*6 and 4 CYP2B6*6/*6) received orally administered bupropion alone and during daily treatment with metamizole 1500 mg day(-1) (500 mg tablet taken three times daily) for 4 days. Serial blood samples were obtained up to 48 h after each bupropion dose. RESULTS: After metamizole treatment relative to bupropion alone, the geometric mean ratios (GMRs) and 90% confidence interval (CI) of the AUC(0,∞) ratio of 4-hydroxybupropion over bupropion were 1.99 (1.57, 2.55) for the CYP2B6*1/*1 group, 2.15 (1.53, 3.05) for the CYP2B6*1/*6 group and 1.86 (1.36, 2.57) for the CYP2B6*6/*6 group. The GMRs and 90% CI of bupropion were 0.695 (0.622, 0.774) for AUC(0,∞) and 0.400 (0.353, 0.449) for C(max) , respectively. The corresponding values for 4-hydroxybupropion were 1.43 (1.28, 1.53) and 2.63 (2.07, 2.92). The t(1/2) value was significantly increased for bupropion and decreased for 4-hydroxybupropion. The t(max) values of bupropion and 4-hydroxybupropion were both significantly decreased. The mean percentage changes in pharmacokinetic parameters among the CYP2B6 genotype groups were not significantly different. CONCLUSIONS: Oral administration of metamizole for 4 days significantly altered the pharmacokinetics of both bupropion and its active metabolite, 4-hydroxybupropion, and significantly increased the CYP2B6-catalyzed bupropion hydroxylation in all of the subjects. Cautions should be taken when metamizole is co-administered with CYP2B6 substrate drugs.

Repeated administration of berberine inhibits cytochromes P450 in humans.

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.

Pharmacokinetic interactions between ilaprazole and clarithromycin following ilaprazole, clarithromycin and amoxicillin triple therapy.

AIM: To investigate the drug interactions between ilaprazole, a new proton pump inhibitor, and clarithromycin following ilaprazole, clarithromycin and amoxicillin combination therapy. METHODS: Twelve healthy Chinese volunteers were recruited in a randomized, open-label, 3-period crossover study. All subjects were administered ilaprazole (5 mg), clarithromycin (500 mg) or a triple therapy, including ilaprazole (5 mg), clarithromycin (500 mg) and amoxicillin (1 g), twice daily for 6 consecutive days. On the 7th day, the drugs were given once, and blood samples were collected and analyzed using a well-validated HPLC/MS/MS method. RESULTS: Following the triple therapy, the peak concentration (C(max)) and the area under the concentration-time curve from 0 h to 12 h (AUC(0→12)) of ilaprazole were significantly decreased, as compared with the single medication group (C(max):1025.0±319.6 vs 1452.3±324.6 ng/mL; AUC(0→12): 9777.7±3789.8 vs 11363.1±3442.0 ng·h/mL). Similar changes were found for ilaprazole sulfone (C(max): 5.9±0.5 vs 9.3±1.7 ng/mL; AUC(0→12): 201.4±32.1 vs 277.1±66.2 ng·h/mL). The triple therapy significantly elevated the C(max) of clarithromycin (3161.5±702.2 vs 2541.9±476.2 ng/mL). CONCLUSION: The H pylori eradication therapy with clarithromycin, amoxicillin and ilaprazole may cause pharmacokinetic interactions that decrease the amount of ilaprazole and its metabolites and elevate that of clarithromycin.

Tunable cyano substituents in D-A conjugated polymers accessed via direct arylation for photocatalytic hydrogen production.

2-Styrylthiophene-based donor-acceptor linear conjugated polymers with tunable cyano substituents are atom-economically obtained via direct C-H arylation for platinum-free photocatalytic hydrogen production, affording a HER of up to 9.79 mmol h-1 g-1.

Correction: EDOT-based conjugated polymers accessed via C-H direct arylation for efficient photocatalytic hydrogen production.

[This corrects the article DOI: 10.1039/D1SC05784G.].