Gemcitabine enhances pharmacokinetic exposure of the major components of Danggui Buxue Decoction in rat via the promotion of intestinal permeability and down-regulation of CYP3A for combination treatment of non-small cell lung cancer.

CONTEXT: Danggui Buxue Decoction (DBD), a traditional Chinese medicine formula, has the potential to enhance the antitumor effect of gemcitabine in non-small cell lung cancer (NSCLC) treatment by increasing gemcitabine's active metabolites. However, whether gemcitabine affects the pharmacokinetics of DBD's major components remains unclear. OBJECTIVE: This study evaluates the herb-drug interaction between DBD's major components and gemcitabine and validates the underlying pharmacokinetic mechanism. MATERIALS AND METHODS: The pharmacokinetics of 3.6 g/kg DBD with and without a single-dose administration of 50 mg/kg gemcitabine was investigated in Sprague-Dawley rats. The effects of gemcitabine on intestinal permeability, hepatic microsomal enzymes in rat tissues, and CYP3A overexpressing HepG2 cells were determined using western blot analysis. RESULTS: The combination of gemcitabine significantly altered the pharmacokinetic profiles of DBD's major components in rats. The Cmax and AUC of calycosin-7-O-ß-d-glucoside notably increased through sodium-glucose transporter 1 (SGLT-1) expression promotion. The AUC of ligustilide and ferulic acid was also significantly elevated with the elimination half-life (t1/2) prolonged by 2.4-fold and 7.8-fold, respectively, by down-regulating hepatic CYP3A, tight junction proteins zonula occludens-1 (ZO-1) and occludin expression. DISCUSSION AND CONCLUSIONS: Gemcitabine could modulate the pharmacokinetics of DBD's major components by increasing intestinal permeability, enhancing transporter expression, and down-regulating CYP3A. These findings provide critical information for clinical research on DBD as an adjuvant for NSCLC with gemcitabine and help make potential dosage adjustments more scientifically and rationally.

Toxicity and risk assessment of mercury exposures from cinnabar and Baizi Yangxin Pills based on pharmacokinetic and tissue distribution studies.

ETHNOPHARMACOLOGICAL RELEVANCE: Baizi Yangxin Pills (BZYXP), a popular cinnabar (α-HgS) contained Traditional Chinese Medicines (TCMs) is widely used in clinical trials. However, mercury is one of the most toxic elements. The adverse effects of cinnabar-containing TCMs have been occasionally reported in recent years, leading to the growing concerns about their toxicity and safety. AIM OF THE STUDY: The health risks of BZYXP and cinnabar related to the mercury exposures were evaluated through blood pharmacokinetic and tissue distribution studies in rats. MATERIALS AND METHODS: The distribution of absorbed mercury in rats' blood and tissues were measured by the developed cold-vapor atomic fluorescence spectrometric method. And the tissue damages were determined through the histopathological examinations. For single dose study, the low and high oral doses were equivalent to 1 and 10-fold therapeutic dose, respectively. The multiple doses study was conducted at low and high dose levels every 12 h for 30 consecutive days. RESULTS: Significant differences of mercury blood pharmacokinetic and tissue distribution characteristics were observed between the corresponding BZYXP and cinnabar groups. The herbal ingredients in BZYXP promoted the absorption of bio-accessible mercury of cinnabar and prolonged the elimination process, posing potential health risks. Although mercury was found easily accumulated in kidney, liver and brain tissues, kidney and liver didn't show obvious damages even after 30 days consecutive administration of BZYXP or cinnabar at 10-fold clinically equivalent doses. But brain did show some histopathological changes, and autonomic activities of rats decreased, pointing the potential neurotoxicity. CONCLUSIONS: Mercury tend to be accumulated especially when over-dose or prolonged medication with cinnabar-containing TCMs are given. The mercury exposures even at therapeutic doses of BZYXP or cinnabar do pose health risks from the neurotoxicity point of view.

[Pharmacokinetics of mercury after oral administration of cinnabaris and Fufang Niuhuang Xiaoyan capsule in rats].

Fufang Niuhuang Xiaoyan capsule was a classical compound prescription with the efficacy of heat-clearing, detoxification, sedation and anti-inflammation, with cinnabaris as one of its active ingredients. The study focuses on the pharmacokinetics of mercury in rats after oral administration of cinnabaris and Fufang Niuhuang Xiaoyan capsule, in order to explore the effect of combined traditional Chinese medicines on mercury metabolism. In this study, the method of nitric-perchloric acid digestion system coupled with cold atomic-atomic fluorescence spectroscopy (CV-AFS) was adopted to accurately determine mercury in whole blood of rats. Fufang Niuhueng Xiaoyan capsule had three dose schemes of oral administration, namely equivalent clinical dose, 3 times of equivalent clinical dose and 10 times of equivalent clinical dose; And the doses of oral administration of cinnabaris was calculated according to that of Fufang Niuhuang Xiaoyan capsule. SPF grade healthy SD rats were fasted overnight before the oral administration with cinnabaris suspension (or Fufang Niuhuang Xiaoyan capsule suspension). After oral administration of different doses of cinnabaris, no obvious changes in tmax and MRT were observed, while Cmax/dose, AUC0-48 h/dose and AUC0-∞/dose decreased with the increase in dose, indicating that total mercury absorption in body was declining. As the dose increased, Ke, CL/F decreased, and t1/2 increased, indicating that the elimination slowed down, and mercury metabolism showed non-linear dynamic characteristics within a certain range of dose (22-220 mg•kg⁻¹). The total mercury metabolism in the whole blood of rats after oral administration with different doses of Fufang Niuhuang Xiaoyan capsule also showed non-linear dynamic characteristics. The results were correlated with the low solubility of cinnabaris in the body. Compared with cinnabaris, Fufang Niuhuang Xiaoyan capsule showed no obvious changes in V/F and MRT, while Ke, CL/F, tmax decreased, and t1/2, Cmax/dose, AUC0-48 h/dose, AUC0-∞/dose increased significantly. The results showed that Fufang Niuhuang Xiaoyan capsule accelerated absorption, slowed down elimination and improved the total absorption of mercury in the whole blood, indicating that Fufang Niuhuang Xiaoyan capsule may contain components for promoting absorption and alleviating elimination of mercury. Fufang Niuhuang Xiaoyan capsule had an impact on the pharmacokinetics of cinnabaris, and long-term administration of cinnabaris (Fufang Niuhuang Xiaoyan capsule) was possible to cause accumulation of mercury in the body. This study could explain changes in efficacy of Fufang Niuhuang Xiaoyan capsule, evaluate the rationality of compound medicines containing toxic elements and provide scientific basis for the rational and safe use of Fufang Niuhuang Xiaoyan capsule.

Simultaneous LC-MS/MS determination of five tripterygium pyridine alkaloids in dog plasma and its application to their pharmacokinetic study after oral administration of tripterygium glycosides tablets.

A sensitive and selective liquid chromatography tandem mass spectrometric method was developed and validated for the simultaneous determination of five pyridine alkaloids contained in tripterygium glycosides tablets (triptolide, wilforine, wilforgine, wilfording and wilfortrine) in dog plasma. The analysis was carried out on a Sepax GP-Phenyl column using a mixture of methanol and 10mmol/L ammonium formate buffer solution containing 0.1% formic acid (75:25, v/v) as the mobile phase pumped at a flow-rate of 1.0mL/min. All MS data were obtained in the positive ESI mode with selective multiple reaction monitoring of ion transitions. The method was fully validated to be accurate and precise with a linear range of 0.2-1000ng/mL for triptolide and 0.05-1000ng/mL for the other four pyridine alkaloids. The intra-day and inter-day precisions (relative standard deviation, RSD, %) were within 10.6% and 14.0%, respectively, and the relative error (RE, %) were all less than 13.1%. The method was successfully applied to multi-components pharmacokinetic study of the five pyridine alkaloids in beagle dogs after a single oral administration of 3mg/kg and 30mg/kg tripterygium glycosides tablets, respectively, and a multiple oral administration of 30mg/kg for 6 consecutive days.

Rapid and sensitive analysis of multiple bioactive constituents in tripterygium glycosides tablets using liquid chromatography coupled with time-of-flight mass spectrometry.

A simultaneous determination method based on liquid chromatography coupled with time-of-flight mass spectrometry was developed for the analysis of 11 bioactive constituents in tripterygium glycosides tablets, an immune and inflammatory prescription used in China. The analysis was fully optimized on a 1.8 µm particle size C18 column with linear gradient elution, permitting good separation of the 11 analytes and two internal standards in 21 min. The quantitation of each target constituent was carried out using the narrow window extracted ion chromatograms with a ±l0 ppm extraction window, yielding good linearity (r(2) > 0.996) with a linear range of 10-1000 ng/mL. The limits of quantitation were low ranging from 0.25 to 5.02 ng/mL for the 11 analytes, and the precisions and repeatability were better than 1.6 and 5.3%, respectively. The acceptable recoveries obtained were in the range of 93.4-107.4%. This proposed method was successfully applied to quantify the 11 bioactive constituents in commercial samples produced by nine pharmaceutical manufacturers to profile the quality of these preparations. The overall results demonstrate that the contents of the 11 bioactive constituents in different samples were in great diversity, therefore, the quality, clinical safety, and efficacy of this drug needs further research and evaluation.

Impact on L-carnitine Homeostasis of Short-term Treatment with the Pivalate Prodrug Tenofovir Dipivoxil.

Pivalate-generating prodrugs have been suggested to cause clinically significant hypocarnitinaemia. Tenofovir dipivoxil, a novel ester prodrug of tenofovir, can be used for treatment for hepatitis B and HIV infection and it was necessary to evaluate the effect of its treatment on carnitine homeostasis. We sought to investigate the effect of Class 1 drug tenofovir dipivoxil on endogenous L-carnitine level during a 72-hr test in healthy Chinese volunteers and to establish a suitable dose of L-carnitine nutritional supplement for patients who were administered short-term tenofovir dipivoxil tablets for treatment for hepatitis B and herpes simplex virus infection. Tenofovir dipivoxil was administered in one of eight dosing regimens (single dose 150, 300 and 600 mg, multiple dose 300, 450, and 600 mg, multiple dose 450 (600) mg tenofovir dipivoxil and 0.5 g L-carnitine) to gender-balanced groups of 84 healthy Chinese volunteers. Plasma concentrations of L-carnitine were quantified before, during and after treatment. Plasma L-carnitine concentrations fell during tenofovir dipivoxil dosing. The nadir in L-carnitine concentration was dependent on the dose of tenofovir dipivoxil and it decreased from 6.1 ± 0.6 to 4.4 ± 0.8 µg/ml, 6.1 ± 1.8 to 3.3 ± 1.2 µg/ml, 6.2 ± 0.6 to 2.5 ± 0.5 µg/ml for single doses of 150, 300, 600 mg tenofovir dipivoxil tablets and from 6.0 ± 1.4 to 2.1 ± 1.5 µg/ml, 6.2 ± 0.4 to 0.9 ± 0.5 µg/ml for multiple doses of 450, 600 mg tenofovir dipivoxil tablets, respectively. Short-term administration of tenofovir dipivoxil results in hypocarnitinaemia and increased losses of carnitine in resulting of minor adverse events of decreased food appetite, nausea, abdominal distention and muscle weakness.

[Effects of combination of Salvia miltiorrhiza and Panax notoginseng on the pharmacokinetics of their major bioactive components in Beagle dog].

After oral administration of Salvia miltiorrhiza (Danshen in Chinese), Panax notoginseng (Sanqi in Chinese) and Danshen Sanqi combination suspensions to Beagle dogs, the plasma concentration-time profiles of danshensu, tanshinone II(A), cryptotanshinone, notoginsenoside R1, ginsenoside Rg1 and Rb1 were analyzed by LC-MS/MS. Pharmacokinetic parameters were calculated and analyzed with BAPP 2.0 software. The results showed that the Cmax and AUC of danshensu, notoginsenoside R1, ginsenoside Rg1 and Rb1 in Danshen Sanqi combination group all decreased in comparison with those of Danshen or Sanqi given alone, while the CLz/F and Vz/F increased to some extent. No significant differences of the pharmacokinetics of tanshinone II(A) and cryptotanshinone were observed between groups.

[Study on HPLC fingerprint of flavonoids from Houttuynia cordata by comparing with fingerprint reference].

OBJECTIVE: To establish a stable and repeatable HPLC fingerprint standard and evaluate the flavonoids from Houttuynia cordata qualitatively and quantitatively. METHODS: HPLC separation was performed on a C18 column with methanol-0.1% phosphoric acid mixed solution as mobile phase in gradient elution mode. The fingerprint reference was determined as one of the most typical chromatograms and used to be compared with other samples through Cosine and Relative Euclid Distance methods, thus the chromatographic fingerprints of flavonoids from Houttuynia cordata were evaluated by constitutes and contents, respectively. RESULTS: Fourteen mutual peaks were fixed in the HPLC fingerprint of flavonoids from Houttaynia cordata. It showed good results in validation tests in which the quercitrin's peak was set as the reference peak to calculate relative retention time and area of other peaks in the chromatograms, and the RSD were less than 0.2% and 5.0%, respectively. The linear ranges for quercitrin was 1.07-83.4 microg/mL (r=0.9999) and the average recovery was 100.3%. CONCLUSION: The method shows good repeatability, ruggedness and reliability. Comparing with the established reference fingerprint, the evaluation system including Cosine and Relative Euclid Distance methods lays dependable foundation for controlling the quality of Houttuynia cordata.

[HPLC tandem-mass spectrometric analysis of the chemical components and decomposition products of allicin extract of garlic].

To analyze the chemical components and decomposition products in allicin extract of garlic, the chemical components screening and identification were made with HPLC-MS/MS method by full scan TIC MS, HPLC retention time, product MS spectra and chemical reference standards. The stability of the extract in water and alcoholic solutions was also investigated. There were five major components in allicin extract which were all identified as thiosulfinates. The extract was stable for at least 3 months when stored at -20 degrees C as water solution, but obvious decomposition was observed with the increase of alcoholic concentration. The decomposition products were also identified by HPLC-MS/MS.

Effects of the coexisting diterpenoid tanshinones on the pharmacokinetics of cryptotanshinone and tanshinone IIA in rat.

Tanshinone II(A) and cryptotanshinone are the main pharmacologically active components in the Chinese herb drug Salvia miltiorrhiza Bge. The objective of this study was to investigate the effect of coexisting tanshinones in liposoluble ethanol extract of S. miltiorrhiza Bge. on the rat pharmacokinetics of tanshinone II(A) and cryptotanshinone after oral intra-gavage administration of the tanshinones extract. Rats were given the tanshinones extract 23.3 mg/kg (equivalent to 5.7 mg/kg cryptotanshinone and 8.0mg/kg tanshinone II(A)), cryptotanshinone 5.7 mg/kg, or tanshinone II(A) 8.0 mg/kg orally under overnight fasted conditions. Blood samples were taken at predetermined sampling time interval and the concentrations of cryptotanshinone and tanshinone II(A) were determined by a validated LC-MS/MS method. The peak plasma concentrations of cryptotanshinone and tanshinone II(A) were considerably increased (about 8 and 10 folds) after oral administration of the extract in comparison with the equivalent dose of single component administration, respectively. The areas under the plasma concentration-time curve (AUC) of cryptotanshinone and tanshinone II(A) were both significantly increased (P<0.001) as well. Tanshinone II(A) was also found after the administration of cryptotanshinone alone, and the fraction of metabolism of tanshinone II(A) was 21.0+/-4.1%. Therefore, the pharmacokinetics of cryptotanshinone and tanshinone II(A) in rats after administration of the tanshinones extract were significantly affected by the coexisting tanshinones. In conclusion, the herb-drug interactions occurred between coexisting tanshinones and cryptotanshinone or tanshinone II(A) affected their absorption, transformation and metabolism.

[Pharmacokinetic interactions between the main components in the extracts of Salvia miltiorrhiza Bge. in rat].

The pharmacokinetics of the main components of protocatechualdehyde, salvianolic acid B, tanshinone II(A), cryptotanshinone, and the hydrophilic or lipophilic extracts of Salvia Miltiorrhiza Bge., in rat plasma were studied after oral administration separately to explore the interactions between them. Some components in the hydrophilic extract depress the absorption of the protocatechualdehyde, on the contrary, enhance the absorption of the salvianolic acid B and depress its elimination rate. The concomitant components in the lipophilic extract might enhance the absorption of cryptotanshinone and its distribution from the centre compartment to the peripheral compartment, and the metabolism to tanshinone II(A). The 'concomitant components' in the extract of Chinese material medica had significant effect on the pharmacokinetics of its 'marker components'. It can not only be rival, synergic, but also have the effects on metabolism. Therefore the traditional Chinese medicine was a complicated system, It should be taken a scientific and dialectic view in the research and development processes.

[Excretion of (-)-clausenamide in rats].

AIM: To study the excretion of (-)-clausenamide in rats. METHODS: The urine, feces and bile were collected at predetermined time points after (-)-clausenamide was orally administrated to 6 rats (30 mg x kg(-1)). The concentrations of (-)-clausenamide and its metabolite 6-OH-(-)-clausnamide were determined by HPLC-MS/MS method using glipzide as the internal reference, and the accumulative excretion amount of (-)-clausenamide and 6-OH-(-)-clausenamide was calculated in the urine, feces and bile, separately. RESULTS: (-)-Clausenamide was recovered mostly (44%) from feces in 112 hours, 7.1% was found from urine in 120 hours and 0.013% was detected from bile in 24 hours. The accumulative excretions of 6-OH-(-)-clausenamide were 0.92% , 0.46% and 0.0003% of the administered dose from feces, urine and bile, respectively. CONCLUSION: The major amount of (-)-clausenamide was recovered from feces after (-)-clausenamide was orally administrated to rats (30 mg kg(-1)).

[Pharmacokinetics of (-)-clausenamide and its major metabolite 6-hydroxyl-clausenamide in beagle dogs by HPLC/MS].

UNLABELLED: To establish a sensitive and accurate method to study the pharmacokinetics of (-)-clausenamide [(-)-clau] and its major metabolite 6-hydroxyl-clausenamide (6-OH-clau) in the plasma of the Beagle dog. METHODS: (-)-Clau was orally administered to six Beagle dogs at the dose of 30 mg x kg(-1), venous blood from front leg was sampled and plasma was separated for analysis. After extraction with ethyl acetate, the plasma samples were analyzed by HPLC/MS and the mobile phase was a mixture of methanol-water-acetic acid (60: 40: 0. 8) at the flow rate of 1.0 mL x min(-1). The API-ES positive ion SIM detection was carried out for the detection of both (-)-clau ([M + H] (+), m/z 298 ) and 6-OH-clau ([M + H - H2 O](+), m/z 296) with glipzide (glip) ([M + H](+), m/z 446) as internal standard. The pharmacokinetic parameters were calculated by 3P97 software. RESULTS: There was good linear relationship ( r > 0. 999) between the SIM responses and the concentrations for (-)-clau and 6-OH-clau at the range from 1.0 to 200 ng x mL(-1) and 0.2 to 40.0 ng x mL(-1), respectively. The absolute recovery was greater than 85%. The plasma concentration-time curves of (-)-clau and 6-OH-clau were both best fitted to a two-compartment model. The C(max) of (-)-clau and 6-OH-clau were (21 +/- 10) ng x mL(-1) and (3.9 +/- 2.2) ng x mL(-1), T(max) were (0.8 +/- 0.5) h and (1.3 +/- 0.5) h, T 1/2 alpha were (0.9 +/- 0.6) hand (1.4 +/- 0.6) h, T 1/2 beta were (19 +/- 23) hand (13 +/- 12) h, AUC(0-24 h) were (69 +/- 14) h x ng x mL(-1) and (12 +/- 7) h x ng x mL(-1) respectively. CONCLUSION: The established HPLC/MS method was sensitive and specific for the determination of (-)-clau. It was shown that the absorption and first phase elimination of (-)-clau were very quick in Beagle dogs, but the terminal elimination was very slow. The plasma concentration profile of its major metabolite 6-OH-clau was similar to (-)-clau and the AUC was relatively small in comparison with (-)-clau.