Objectives: Radix Polygoni Multiflori Praeparata (RPMP) and Dioscorea Bulbifera Rhizomes (DBR) are used in Chinese herbal medicine and have been frequently reported for adverse reactions on liver. In this research, we...Objectives: Radix Polygoni Multiflori Praeparata (RPMP) and Dioscorea Bulbifera Rhizomes (DBR) are used in Chinese herbal medicine and have been frequently reported for adverse reactions on liver. In this research, we aimed to evaluate in vivo effects of RPMP and DBR on rat cytochrome P450 enzymes (CYP1A2, CYP2E1 and CYP3A2) with their respective substrates as probes. Methods: Rats were orally administered RPMP, DBR and RPMP/DBR combination at 12, 10 and (12 + 10) g/kg, respectively, or saline as a control, once daily for 7 days. Thereafter, a cocktail containing 10 mg/kg caffeine, 20 mg/kg chlorzoxazone and 10 mg/kg dapsone was tail vein injected to rats. At defined time points, plasma drug concentrations were simultaneously evaluated by HPLC. Pharmacokinetic parameters simulated by DAS software were used to assess RPMP and/or DBR effects on cytochrome P450 enzymes activity. ANOVA and Dunnett’s test were used for data analysis. Results: Caffeine metabolism was enhanced in RPMP animals and reduced after pretreatment with DBR, but no effect was observed in RPMP/DBR combination group. Chlorzoxazone and dapsone metabolism was enhanced in both RPMP and DBR groups and consequently in combination group. The data suggested that RPMP independently induces rat CYP1A2, CYP2E1 and CYP3A2 activity, while DBR independently inhibits activity of rat CYP1A2 and induces that of CYP2E1 and CYP3A2. RPMP/DBR combination showed no significant benefit compared with the two drugs alone and even showed a neutralized effect in CYP1A2 activity. Conclusions: Caution is needed when RPMP and/or DBR are co-administered with drugs metabolized by human CYP1A2, CYP2E1 and CYP3A4.展开更多
In this study,three-probe error separation was developed with three chromatic confocal displacement sensors for roundness measurement.Here,the harmonic suppression is discussed first to set suitable orientation angles...In this study,three-probe error separation was developed with three chromatic confocal displacement sensors for roundness measurement.Here,the harmonic suppression is discussed first to set suitable orientation angles among three sensors.Monte Carlo simulation is utilized to test the error separation and optimize the orientation angles and off-axial distance.The experimental setup is established using chromatic confocal sensors with a precise rotary platform.The experimental results show that the measured roundness with an orientation-angle combination of(0°,90.1°,and 178.6°)is much better than that of another nonoptimal selection(0°,90.4°,and 177.4°).The roundness error is only 0.7%between the proposed measurement system and an expensive ultraprecision roundness meter.Furthermore,it is proven that the eccentricity distance should be decreased as small as possible to improve the measurement accuracy.In sum,this paper proposes a feasible method for roundness measurement with reliable simulations,easily integrated sensors,and an ordinary precision rotary platform.展开更多
文摘Objectives: Radix Polygoni Multiflori Praeparata (RPMP) and Dioscorea Bulbifera Rhizomes (DBR) are used in Chinese herbal medicine and have been frequently reported for adverse reactions on liver. In this research, we aimed to evaluate in vivo effects of RPMP and DBR on rat cytochrome P450 enzymes (CYP1A2, CYP2E1 and CYP3A2) with their respective substrates as probes. Methods: Rats were orally administered RPMP, DBR and RPMP/DBR combination at 12, 10 and (12 + 10) g/kg, respectively, or saline as a control, once daily for 7 days. Thereafter, a cocktail containing 10 mg/kg caffeine, 20 mg/kg chlorzoxazone and 10 mg/kg dapsone was tail vein injected to rats. At defined time points, plasma drug concentrations were simultaneously evaluated by HPLC. Pharmacokinetic parameters simulated by DAS software were used to assess RPMP and/or DBR effects on cytochrome P450 enzymes activity. ANOVA and Dunnett’s test were used for data analysis. Results: Caffeine metabolism was enhanced in RPMP animals and reduced after pretreatment with DBR, but no effect was observed in RPMP/DBR combination group. Chlorzoxazone and dapsone metabolism was enhanced in both RPMP and DBR groups and consequently in combination group. The data suggested that RPMP independently induces rat CYP1A2, CYP2E1 and CYP3A2 activity, while DBR independently inhibits activity of rat CYP1A2 and induces that of CYP2E1 and CYP3A2. RPMP/DBR combination showed no significant benefit compared with the two drugs alone and even showed a neutralized effect in CYP1A2 activity. Conclusions: Caution is needed when RPMP and/or DBR are co-administered with drugs metabolized by human CYP1A2, CYP2E1 and CYP3A4.
基金This work was supported by the National Natural Science Foundation of China(61905129)Start-up Funding of Tsinghua Shenzhen International Graduate School,Tsinghua University(QD2020001N)Shenzhen Stable Supporting Program(WDZC20200820200655001).
文摘In this study,three-probe error separation was developed with three chromatic confocal displacement sensors for roundness measurement.Here,the harmonic suppression is discussed first to set suitable orientation angles among three sensors.Monte Carlo simulation is utilized to test the error separation and optimize the orientation angles and off-axial distance.The experimental setup is established using chromatic confocal sensors with a precise rotary platform.The experimental results show that the measured roundness with an orientation-angle combination of(0°,90.1°,and 178.6°)is much better than that of another nonoptimal selection(0°,90.4°,and 177.4°).The roundness error is only 0.7%between the proposed measurement system and an expensive ultraprecision roundness meter.Furthermore,it is proven that the eccentricity distance should be decreased as small as possible to improve the measurement accuracy.In sum,this paper proposes a feasible method for roundness measurement with reliable simulations,easily integrated sensors,and an ordinary precision rotary platform.
