Enhancing effects of different dosages of borneol on pharmacokinetics of salvanic acid B after oral administration to rats

The main purpose of this study was to illustrate the effect of borneol on pharmacokinetics of salvianolic acid B (SalB) in rats after oral administration of SalB with different doses of borneol. The concentrations of SalB in rat plasma were determined by an established and validated LC-MS/MS method. Our data showed that when 20, 40, and 80 mg kg^? 1 of borneol were orally administrated with SalB at 50 mg kg^? 1, C _max of SalB was increased by 18.4%, 55.8%, and 103.2% compared with that of SalB alone. And AUC_0 ? t of SalB in plasma was increased by 14.4%, 48.5%, and 123.3%, respectively. The results indicated that borneol is able to enhance the intestinal absorption and relative bioavailability of SalB, with a positive dose-dependent relationship. The described herb–drug interactions might prove the scientific rationality of the compatible ratio of traditional Chinese medicines.     

硝苯地平对美托洛尔大鼠体内药动学的影响

目的建立一种LC-MS/MS法测定大鼠血浆中美托洛尔的浓度,研究硝苯地平对美托洛尔在大鼠体内药动学的影响。方法采用C18柱分离,用普萘洛尔作内标,流动相:乙腈-水-甲酸(体积比为40.0∶60.0∶0.1),用乙酸乙酯提取处理,采用ESI源,正离子方式检测,扫描方式为多反应监测(multiple reaction monitoring,MRM)。结果单独给药组与联合给药组主要药动学参数如下:ρmax分别为(502.8±67.0)和(623.8±137.3)μg.L-1,tmax分别为(0.50±0.08)和(0.58±0.13)h,t1/2分别为(1.25±0.80)和(1.53±0.58)h,AUC0-t分别为(442.8±50.9)和(730.8±218.2)μg.h.L-1,MRT0-t分别为(1.24±0.14)和(1.68±0.41)h,Cl/F分别为(39.0±3.41)和(25.4±7.46)L.h-.1kg-1,AUC0-t、MRT0-t、Cl/F具有显著性差异(P<0.05),其他药动学参数无显著性差异(P>0.05)。结论硝苯地平影响美托洛尔在大鼠体内吸收和消除的药动学过程。     

Effect of long-term coadministration of compound glycyrrhizin tablets on the pharmacokinetics of mycophenolic acid in rats

1.?Mycophenolic acid (MPA), having high-protein affinity, is an immunodepressant and the genuine-active ingredient of enteric-coated mycophenolate sodium (EC-MPS) tablet that has been widely used in combination with tacrolimus or cyclosporine to prevent acute rejection after organ transplantation. Moreover, MPA mainly experiences glucuronidation and its metabolites are partly transported by multidrug resistance-associated protein (Mrp) 2 into bile then reforms MPA via enterohepatic circulation.

2.?Glycyrrhizin (GL), having high-protein affinity, is the main active ingredient of compound glycyrrhizin tablet, which is often prescribed with EC-MPS, tacrolimus or cyclosporine to prevent drug-induced hepatitis. In addition, GL can inhibit Mrp2 and selectively induce CYP3A and UGTs; and it also undergoes enterohepatic circulation.

3.?After 14 days of coadministration of compound GL tablets with the capsules of EC-MPS tablets, the AUC_0–48?h of total and free MPA was dramatically increased, and the clearance of total and free MPA was apparently decreased. It would seem reasonable that our data appear to support further investigation of this drug–drug interactions in the clinic and more careful monitoring of drug levels as well as clinical effect and toxicity in patients receiving the combination of these two agents.     

贝那普利对氨氯地平药代动力学的影响

目的：比较受试者口服复方贝那普利（含盐酸贝那普利10mg和苯磺酸氨氯地平5mg）和氨氯地平（5mg）后体内氨氯地平的药代动力学特征，研究氨氯地平和贝那普利之间的相互作用。方法：采用两制剂、两周期随机交叉试验设计，12名男性健康受试者自身对照，口服复方贝那普利或氨氯地平。应用LC／MS／MS方法测定氨氯地平的血药浓度，并采用WinNonLin软件计算药代动力学参数。结果：复方和单方制剂中氨氯地平的平均药代动力学参数如下：Cmax分别为（2．6±0．6）、（2．8±0．7）μg／L，tmax分别为（5．8±1．3）、（5．3±1．0）h，AUC0-144分别为（99±39）、（109±26）μg·L^-1·h，t1/2分别为（37±6）、（44±12）h。各参数在两制剂间均无统计学意义。结论：贝那普利对氨氯地平在人体内的药动学过程没有显著影响。     

氨氯地平对贝那普利及其代谢物药动学的影响*

目的:比较受试者口服复方贝那普利(含盐酸贝那普利10mg和苯磺酸氨氯地平5mg)和贝那普利(10mg)后体内的药动学特征,研究贝那普利和氨氯地平之间的相互作用。方法:采用两制剂、两周期交叉实验设计,12例健康受试者自身对照,口服复方贝那普利或贝那普利。应用LC/MS/MS方法测定贝那普利的血药浓度,并采用WinNonLin软件计算药动学参数。结果:①复方和单方制剂中贝那普利原型的平均药动学参数如下:C_(max) (150.3±68.4)和(154.1±79.9)μg·L~(-1),T_(max)(0.53±0.18)和(0.46±0.16)h,AUC_(0-10b)(138.9±61.9)和(132.5±59.4)μg·h·L~(-1),t_(1/2)(1.2±0.7)和(1.5±1.1)h。②复方和单方制剂中代谢物贝那普利拉的平均药动学参数如下:C_(max)(146.7±79.8)和(119.3±50.9)μg·L~(-1),T_(max)(2.0±0.9)和(1.6±0.5)h,AUC_(0～10h)(546.7±218.5)和(515.1±230.9)μg·h·L~(-1),各参数在两制剂间均不存在显著性差异。结论:氨氯地平对贝那普利在人体内的药动学过程没有显著影响。     

苯磺酸氨氯地平片在健康人体的生物等效性

目的 研究苯磺酸氨氯地平片(抗高血压药)的相对生物利用度,并求证该制剂的生物等效性.方法 24名男性健康受试者随机交叉给药,先后口服单剂量试验制剂及参比制剂苯磺酸氨氯地平片剂5 mg,采用LC-MS/MS法测定血药浓度,计算2者的药代动力学参数及相对生物利用度,并评价2制剂的生物等效性.结果 口服试验制剂及参比制剂5 mg的主要药代动力学参数如下:t1/2分别为(47.15±17.28)、(43.22 ± 16.63)h;tmax分别为(5.81±2.09)、(6.38±2.33)h;Cmax分别为(4.77±1.28)、(4.37±1.14)ng·mL-1;AUC0-t分别为(176.39±57.95)、(182.55±58.36)ng·mL-1h;AUC0-t分别为(185.65±59.01)、(192.83±62.72)ng·mL-1h;试验制剂对于参比制剂的平均相对生物利用度F值:AUC0-t为(98.1±18.5)%,AUC0-∞为(98.6±20.0)%;tmax经非参数检验无显著性差异,试验制剂的平均生物利用度(AUC0-t、AUC0-∞)均大于98%,2种制剂的Cmax、AUC0-t和AUC0-∞双向单侧t检验和[1-2α]置信区间法的等效性分析均为合格,tmax经非参数秩和检验无显著性差异.结论 2种氨氯地平片剂为生物等效制剂.     

苯磺酸氨氯地平/阿托伐他汀钙片在健康人体的药代动力学

目的研究苯磺酸氨氯地平/阿托伐他汀钙片在中国健康人体的药代动力学。方法用随机、开放的拉丁方试验设计,12名健康受试者入选,男女各半,随机交叉单剂量口服苯磺酸氨氯地平/阿托伐他汀钙片、苯磺酸氨氯地平片、阿托伐他汀钙片。用LC-MS/MS测定2种成分的血药浓度,用DAS 2.1软件计算药代动力学参数。结果单次口服苯磺酸氨氯地平/阿托伐他汀钙片与苯磺酸氨氯地平片、阿托伐他汀钙片后药代动力学参数分别如下:t1/2为(46.11±11.05),(7.64±4.23)与(42.75±10.48),(8.42±4.24)h;Tmax为(8.67±3.11),(0.54±0.23)与(6.00±1.71),(1.13±1.55)h;Cmax为(4.13±1.86),(5.19±2.38)与(4.63±1.79),(3.46±2.23)ng.mL-1;AUC0-t为(200.25±91.89),(19.06±6.39)与(210.55±99.58),(19.26±6.55)ng.h.mL-1。结论苯磺酸氨氯地平与阿托伐他汀钙制成复方制剂,对阿托伐他汀的药代动力学无明显影响,氨氯地平的吸收速度略有加快。     

Influence of andrographolide on the pharmacokinetics of warfarin in rats

Context: Andrographolide and warfarin are often used together in clinics in China. However, the herb-drug interaction between andrographolide and warfarin is still unknown.

Objective: This study investigates the herb-drug interaction between andrographolide and warfarin in vivo and in vitro.

Materials and methods: A sensitive and reliable LC-MS/MS method was developed for the determination of warfarin in male Sprague-Dawley rats plasma, and then the pharmacokinetics of orally administered warfarin (0.5?mg/kg) with or without andrographolide (30?mg/kg/day for 7?days) pretreatment was investigated. In addition, Sprague-Dawley rat liver microsomes incubation systems were used to support the in vivo pharmacokinetic data and investigate its potential mechanism.

Results: The method validation results showed that a sensitive and reliable LC-MS/MS method was developed for the determination of warfarin in rat plasma samples. The pharmacokinetic results indicated that co-administration of andrographolide could increase the systemic exposure of warfarin significantly, including area under the curve (118.92?±?18.08 vs. 60.58?±?9.46?μg?×?h/mL), maximum plasma concentration (3.32?±?0.41 vs. 2.35?±?0.25?μg/mL) and t_1/2 (22.73?±?3.28 vs. 14.27?±?2.67?h). Additionally, the metabolic stability of warfarin increased from 23.5?±?4.7 to 38.7?±?6.1?min with the pretreatment of andrographolide, and the difference was significant (p?Discussion and conclusion: In conclusion, andrographolide could increase the systemic exposure of warfarin in rats when andrographolide and warfarin were co-administered, and possibly by slowing down the metabolism of warfarin in rat liver by inhibiting the activity of CYP3A4 or CYP2C9.     

不同剂量薯蓣皂苷元的大鼠体内药动学研究

目的： 研究不同剂量薯蓣皂苷元的大鼠体内药物动力学特征,为阿尔茨海默病的临床前研究提供理论依据。方法： 大鼠灌胃低（17.5 mg·kg^-1）、中（35 mg·kg^-1）、高剂量（70 mg·kg^-1）薯蓣皂苷元后,于不同时间眼眶取血,以延龄草苷作为内标,血浆样品经液-液萃取后采用LC-MS/MS进行测定。利用DAS 2.0计算药动学参数。色谱、质谱条件：采用Sun Fire C₁₈（150 mm×2.1 mm,5 μm）为色谱柱,以甲醇-乙腈-10 mmol·L^-1乙酸铵（86∶11∶3）为流动相,流速为0.3 mL·min^-1,柱温40℃。采用电喷雾离子源（ESI源）,以选择反应监测（MRM）方式并在正离子模式下进行检测,用于定量的离子对分别为m/z 415.5→271.5（薯蓣皂苷元）和m/z 577.5→271.5（内标延龄草苷）。结果： 薯蓣皂苷元血药浓度在1~2 000 ng·mL^-1内线性关系良好,方法回收率在81.7%~83.9%之间,定量下限（LLOQ）为1 ng·mL^-1,日内、日间精密度RSD小于10%。药动学结果表明不同剂量薯蓣皂苷元药-时曲线符合二室模型,主要药动学参数为AUC_0-t分别为1 872,3 144,6 625 ng·min·mL^-1;C_max分别为136,276,470 ng·mL^-1;t_1/2分别为5.73,5.31,6.42 h。结论： 薯蓣皂苷元在17.5~70.0 mg·kg^-1范围内其药动学行为呈线性相关,无动力学行为差异。     

齐多夫定对大鼠内源性左卡尼汀水平及左卡尼汀药动学的影响

目的研究齐多夫定对大鼠内源性左卡尼汀水平及左卡尼汀药动学的影响。方法 Wistar大鼠18只,随机分为A、B、C 3组。A组为空白对照组,不给药;B组单独给予齐多夫定;C组联合给予齐多夫定和左卡尼汀。连续给药45 d,采用LC-MS/MS法测定和比较各组大鼠肌肉和心脏中内源性左卡尼汀水平。另取Wistar大鼠12只,随机分成2组,一组给予左卡尼汀,另一组联合给予左卡尼汀和齐多夫定,采用LC-MS/MS法分别测定2组大鼠给药后左卡尼汀血药质量浓度的经时变化,用DAS 2.1.1软件计算主要药动学参数,并进行统计分析和比较。结果大鼠长期给予齐多夫定后,肌肉中左卡尼汀水平较对照组显著降低,心脏中左卡尼汀水平无显著变化;联合给予齐多夫定和左卡尼汀后,大鼠肌肉中左卡尼汀水平与对照组比较差异无统计学意义,心脏中左卡尼汀水平显著升高。大鼠单独给予左卡尼汀和联合给予齐多夫定和左卡尼汀后的主要药动学参数差异无统计学意义。结论齐多夫定能抑制肌肉组织对左卡尼汀的摄取,接受齐多夫定治疗的同时补充左卡尼汀能减轻齐多夫定引起的不良反应,齐多夫定对大鼠体内左卡尼汀的药动学无显著影响。     

克拉霉素对兰索拉唑及其代谢产物在大鼠体内药动学特征的影响

目的研究克拉霉素对兰索拉唑及其代谢产物5-羟基兰索拉唑和兰索拉唑砜药动学特征的影响。方法 24只大鼠随机分为4组,分别十二指肠给予兰索拉唑(8 mg·kg^-1)+生理盐水、兰索拉唑(8 mg·kg^-1)+酮康唑(5 mg·kg^-1)、兰索拉唑(8 mg·kg^-1)+反苯环丙胺(5 mg·kg^-1)、兰索拉唑(8 mg·kg^-1)+克拉霉素(8 mg·kg^-1)。于给药后不同时间点采集血样,用LC-MS/MS法测定药物浓度。通过对兰索拉唑及5-羟基兰索拉唑和兰索拉唑砜血药浓度的测定,计算大鼠体内药动学参数。以5-羟基兰索拉唑、兰索拉唑砜与兰索拉唑AUC_0→4h的比值分别作为原药经CYP2C19和CYP3A4代谢程度的指标,研究克拉霉素对兰索拉唑代谢的影响。结果克拉霉素显著增加兰索拉唑的AUC_0→4h、MRT和t_1/2,显著降低其CLz。克拉霉素显著降低兰索拉唑砜与兰索拉唑AUC_0→4h的比值,从0.63±0.17降至0.15±0.09（P<0.05）,兰索拉唑砜的ρ_max显著降低,MRT和t_1/2显著延长。克拉霉素对5-羟基兰索拉唑的药动学参数无明显影响。结论克拉霉素在大鼠体内对兰索拉唑CYP3A4主导的磺化代谢抑制作用明显,可明显增加兰索拉唑的生物利用度,对临床治疗消化性溃疡有积极意义。     

苯磺酸氨氯地平片在中国健康受试者中的生物等效性研究

目的:在空腹和餐后条件下,评价两种苯磺酸氨氯地平片在中国健康受试者中的生物等效性。方法:入组24例健康受试者,采用随机、开放、两周期自身交叉试验设计,分别在空腹和餐后条件下给予受试制剂或参比制剂,用液质联用法(LC-MS/MS)测定给药后氨氯地平的血浆浓度,计算主要药代动力学参数,评价受试制剂与参比制剂的生物等效性。结果:健康受试者在空腹口服氨氯地平片后,受试制剂和参比制剂C_max、AUC_0-t、AUC_0-∞的均值分别为(3 462.08±683.46) pg/mL、(159 891.00±45 951.00)pg·mL^-1·h、(194 850.00±63 829.00) pg·mL^-1·h和(3 346.09±710.09) pg/mL、(159 065.00±45 214.00) pg·mL^-1·h、(190 461.00±66 160.00) pg·mL^-1·h;几何均值的比值及其90%置信区间分别为104.82%(100.35%,109.50%)、103.32%(98.13%,108.78%)、103.98%(97.95%,110.38%)。餐后服用盐酸氨氯地平片后,受试制剂和参比制剂C_max、AUC_0-t、AUC_0-∞的均值分别为(2 785.00±600.91) pg/mL、(138 289.00±30 684.00) pg·mL^-1·h、(158 765.00±39 260.00) pg·mL^-1·h和(2 960.00±671.27) pg/mL、(140 990.00±33 326.00) pg·mL^-1·h、(163 996.00±43 606.00) pg·mL^-1·h;几何均数的比值及其90%置信区间分别为94.89%(88.94%,101.23%)、97.96%(92.85%,103.34%)、97.26%(91.61%,103.25%)。结论:在空腹和餐后状态下受试制剂和参比制剂的吸收速度和程度均一致,两制剂生物等效,同时两制剂在中国健康受试人群中具有相似的安全性和耐受性。     

Effects of verapamil on the pharmacokinetics of puerarin in rats

Abstract

1. The oral bioavailability of puerarin is poor which hindered its clinical performance.

2. This study investigates the effects of verapamil on the pharmacokinetics of puerarin in rats.

3. The pharmacokinetics of orally administered puerarin (50?mg/kg) with or without verapamil pretreatment (10?mg/kg/day for 7?days) were investigated. The plasma concentration of puerarin was determined using LC-MS/MS method, and the pharmacokinetics profiles were calculated and compared. Caco-2 cell transwell model was also used to investigate the effects of verapamil on the transport pf puerarin.

4. The results showed that when the rats were pretreated with verapamil, the maximum concentration (C_max) of puerarin increased from 683.7?±?51.2 to 933.5?±?75.8?ng/mL (p?<?0.05), and the area under the concentration-time curve from zero to infinity (AUC_0-inf) also increased from 3687.3?±?444.6 to 5006.1?±?658.6?μg·h/L (p?<?0.05). The Caco-2 cell transwell experiments indicated that verapamil could decrease the efflux ratio of puerarin from 1.90 to 1.19 through inhibiting the activity of P-gp.

5. In conclusion, these results indicated that verapamil could affect the pharmacokinetics of puerarin, possibly by increasing the systemic exposure of puerarin by inhibiting the activity of P-gp.

     

Effects of glycyrrhizin on the pharmacokinetics of puerarin in rats

1. Puerarin has been reported to possess a wide range of pharmacological activities. This study investigated the effects of glycyrrhizin on the pharmacokinetics of puerarin in rats.

2. The pharmacokinetics of orally administered puerarin (50?mg/kg) with or without glycyrrhizin pretreatment (100?mg/kg/day for 7?days) were investigated. The plasma concentration of puerarin was determined using a sensitive and reliable LC-MS/MS method. The pharmacokinetics profiles were calculated and compared. Additionally, a Caco-2 cell transwell model was used to investigate the potential mechanism of glycyrrhizin’s effects on the pharmacokinetics of puerarin.

3. The results showed that when the rats were pretreated with glycyrrhizin, the maximum concentration (C_max) of puerarin decreased from 761.25?±?52.34 to 456.32?±?34.75?ng/mL, and the area under the concentration–time curve from zero to infinity (AUC_0–inf) also decreased from 4142.15?±?558.51 to 2503.74?±?447.57?μg·h/L. The oral clearance of puerarin increased significantly from 12.20?±?1.53 to 20.47?±?3.25?L/h/kg (p?4. In conclusion, these results indicated that glycyrrhizin could affect the pharmacokinetics of puerarin, possibly by decreasing the systemic exposure of puerarin by inducing the activity of P-gp.     

Effects of berberine on the pharmacokinetics of losartan and its metabolite EXP3174 in rats and its mechanism

Context: Losartan and berberine (BBR) are often simultaneously used for the treatment of senile diabetic nephropathy in clinics. However, the potential herb–drug interaction between losartan and BBR is unknown.

Objective: This study investigates the influence of BBR on the pharmacokinetics of losartan and EXP3174, and investigates the effects of BBR on the metabolic stability of losartan.

Materials and methods: The pharmacokinetic profiles losartan and EXP3174 of orally administered losartan (10?mg/kg) with and without pretreatment with BBR (20?mg/kg) within 24?h were determined in Sprague-Dawley rats. The inhibitory effects of BBR on the metabolic stability of losartan were investigated using rat liver microsomes.

Results: The C_max (1.26?±?0.37 versus 1.96?±?0.45?mg/L) and the AUC_(0–t) (8.25?±?0.89 versus 12.70?±?1.42?mg h/L) of losartan were significantly (p?<?0.05) increased by BBR compared to the control, while the C_max (0.97?±?0.15 versus 0.77?±?0.06?mg/L) of EXP3174 was significantly decreased compared to the control (p?<?0.05). The T_max of losartan was prolonged from 0.41?±?0.12 to 0.52?±?0.18?h, but the difference was not significant. However, the T_max of EXP3174 was decreased significantly (p?<?0.05) from 8.14?±?0.36 to 3.33?±?0.28?h. The metabolic stability of losartan was increased from 37.4 to 59.6?min.

Discussion and conclusion: We infer that BBR might increase the plasma concentration of losartan and decrease the concentration of EXP3174 through inhibiting the activity of CYP3A4 or CYP2C9.     

高脂饮食对非洛地平在中国健康受试者体内药动学的影响

目的研究高脂饮食对非洛地平在健康中国人体内的药动学影响。方法 10名健康男性受试者随机分成2组,分别于空腹或进食高脂餐后口服非洛地平缓释片1片(10 mg/片),采用液相色谱-串联质谱(LC-MS/MS)法测定血浆中非洛地平的浓度,用DAS 2.1.1软件计算主要药动学参数,用SPSS 19.0软件对主要药动学参数进行统计学分析。结果受试者于空腹和进食高脂餐后口服非洛地平缓释片的主要药动学参数ρmax、tmax、AUC0-36 h分别为(5.78±3.22)μg·L-1和(9.29±3.47)μg·L-1、(3.11±1.27)h和(5.33±1.80)h、(46.6±24.2)μg·h·L-1和(58.7±18.6)μg·h·L-1;对空腹与进食高脂餐后给药的主要药动学参数采用配对t检验进行统计分析,ρmax和tmax具有显著性差异(P<0.05)。结论高脂饮食可显著降低非洛地平的吸收速度,并显著提高峰浓度。     

阿霉素对去甲斑蝥素在大鼠体内药动学的影响

目的研究大鼠静脉给予阿霉素（ADM）对去甲斑蝥素（NCTD）体内药物动力学的影响。方法用HPLC-MS方法测定ADM和NCTD合并给药与NCTD单独给药大鼠血浆中的NCTD浓度,比较两者的药动学参数。结果ADM和NCTD合并给药组与NCTD单独给药组相比在分布速度常数（α）、分布相半衰期（t1/2α）、中央室向周边室的转运速度常数（k12）3个药动学参数有统计学差异（P〈0.05）,其余药动学参数之间无显著差异（P〉0.05）。结论NCTD与ADM合用时,ADM不会显著影响NCTD在大鼠体内的药动学过程,两药合用增效的原因主要在于药效学上的协同作用。     

Effects of astragaloside IV on the pharmacokinetics of puerarin in rats

Abstract

1. Radix astragali and puerarin are always used together for cardiovascular disease in China clinics.

2. This study investigates the effects of astragaloside IV (AS-IV, the main components of radix astragali) on the pharmacokinetics of puerarin in rats.

3. The pharmacokinetics of orally administered puerarin (50?mg/kg) with or without AS-IV pretreatment (100?mg/kg/day for seven days) were investigated. The plasma concentration of puerarin was determined using LC–MS/MS method, and the pharmacokinetics profiles were calculated and compared. Caco-2 cell transwell model was also used to investigate the effects of AS-IV on the transport pf puerarin.

4. The results showed that when the rats were pretreated with AS-IV, the maximum concentration (C_max) of puerarin decreased from 760 to 467?ng/mL (p?<?.05, n?=?6, 90% CI, 293?±?61.28), and the area under the concentration-time curve from zero to infinity (AUC_0–inf) also decreased from 4097 to 2330?μg·h/L (p?<?.05, n?=?6). The oral clearance of puerarin increased significantly from 11.9 to 22.4?L/h/kg (p?<?.05, n?=?6). The Caco-2 cell transwell experiments indicated that AS-IV could increase the efflux ratio of puerarin from 1.81 to 2.79 through inducing the activity of P-gp.

5. In conclusion, these results indicated that AS-IV could affect the pharmacokinetics of puerarin, possibly by decreasing the systemic exposure of puerarin by inducing the activity of P-gp.

     

Effects of epigallocatechin-3-gallate combined with ascorbic acid and glycerol on the stability and uric acid-lowering activity of epigallocatechin-3-gallate

ContextEpigallocatechin-3-gallate (EGCG) is unstable and easily oxidized, which limits its applications. Ascorbic acid (Vc) is a natural antioxidant.ObjectiveThe effects of EGCG combined with Vc and glycerol on stability and uric acid-lowering activity of EGCG were examined.Materials and methodsEGCG (aqueous solution), EGCG + Vc (aqueous solution), EGCG (glycerol solution) and EGCG + Vc (glycerol solution) were prepared and incubated under different conditions in vitro. The recovery rate of EGCG was calculated by HPLC. Kunming mice were randomly divided into normal control group, model group, allopurinol (5 mg/kg), EGCG (10 mg/kg), EGCG + Vc (both 10 mg/kg), EGCG (10 mg/kg) + glycerol (60%), and EGCG (10 mg/kg) + Vc (10 mg/kg) + glycerol (60%) (n = 6). Allopurinol was injected intraperitoneally to mice, others were administered intragastrically to (2 cases) mice. All mice were continuously administrated for 7 days, once a day.ResultsEGCG recovery rates of EGCG group and EGCG + Vc + glycerol group respectively reached to 32.34 ± 1.86% and 98.90 ± 0.64% when they were incubated for 4 h at 80 °C. EGCG recovery rates reached to 91.82 ± 5.13% (incubated for 6 h at pH 8) and 88.85 ± 2.63% (incubated for 4 h in simulated intestinal fluid) when EGCG incubated with Vc and glycerol. Compared with the model group, UA values of EGCG + Vc + glycerol group reduced by 43.49% while EGCG group reduced by 25.63%. The activities of xanthine oxidase (XOD, 31.41 U/gprot) and adenosine deaminase (ADA, 10.05 U/mgprot), and the mRNA expression levels of glucose transporter 9 (GLUT9, 1.03) and urate transporter 1 (URAT1, 0.44) in EGCG + Vc + glycerol group were notably lower than those of EGCG group (38.12 U/gprot, 13.16 U/mgprot, 1.54, and 0.55). The mRNA expression levels of ATP-binding cassette superfamily G member 2 (ABCG2, 1.39) and organic anion transport 1/2 (OAT1/2, 2.34, 2.53) in EGCG + Vc + glycerol group were notably higher than those of EGCG group (0.57, 1.13, and 1.16).Discussion and conclusionsOur findings suggest that when EGCG used in combination with Vc and glycerol could effectively increase its biology activities and can be generalized to the broader pharmacological studies. This sheds light on the development and application of EGCG in the fields of food and medicine.     

Effects of Danshen tablets on pharmacokinetics of atorvastatin calcium in rats and its potential mechanism

Context: Danshen tablets (DST), an effective traditional Chinese multi-herbal formula, are often combined with atorvastatin calcium (AC) for treating coronary heart disease in the clinic.

Objective: This study investigated the effects of DST on the pharmacokinetics of AC and the potential mechanism.

Materials and methods: The pharmacokinetics of AC (1?mg/kg) with or without pretreatment of DST (100?mg/kg) were investigated using LC-MS/MS. The effects of DST (50?μg/mL) on the metabolic stability of AC were also investigated using rat liver microsome incubation systems.

Results: The results indicated that C_max (23.87?±?4.27 vs. 38.94?±?5.32?ng/mL), AUC_(0–t) (41.01?±?11.32 vs. 77.28?±?12.92?ng h/mL), and t_1/2 (1.91?±?0.18 vs. 2.74?±?0.23?h) decreased significantly (p?t_1/2) of AC was also decreased (25.7?±?5.2 vs. 42.5?±?6.1) with the pretreatment of DST.

Discussion and conclusions: This study indicated that the main components in DST could accelerate the metabolism of AC in rat liver microsomes and change the pharmacokinetic behaviors of AC. So these results showed that the herb-drug interaction between DST and AC might occur when they were co-administered. Therefore, the clinical dose of AC should be adjusted when DST and AC are co-administered.