Ali Fan

Pharmacokinetics, Tissue Distribution, Excretion and Plasma Protein Binding Studies of Wogonin in Rats

Wogonin is a natural anticancer candidate. The purpose of this study was to explore the pharmacokinetic profiles, tissue distribution, excretion and plasma protein binding of wogonin in Sprague—Dawley rats. A rapid, sensitive, and specific LC-MS/MS method has been developed for the determination of wogonin in different rat biological samples. After i.v. dosing of wogonin at different levels (10, 20 and 40 mg/kg) the elimination half-life was approximately 14 min, the AUC0-∞ increased in a dose disproportional manner from 112.13 mg/L·min for 10 mg/kg to 758.19 mg/L·min for 40 mg/kg, indicating a non linear pharmacokinetic profile. After i.g. dosing at 100 mg/kg, plasma levels of wogonin peaked at 28 min with a Cmax value of 300 ng/mL and a very low oral bioavailability (1.10%). Following i.v. single dose (20 mg/kg), wogonin was detected in all examined tissues (including testis) with the highest levels in kidney and liver. Approximately 21% of the administered dose was excreted as unchanged drug (mainly via non-biliairy fecal route (16.33%). Equilibrium dialysis was used to evaluate plasma protein binding of wogonin at three concentrations (0.1, 0.5 and 2 µg/mL). Results indicated a very high protein binding degree (over 90%), reducing substantially the free fraction of the compound.

Investigation on pharmacokinetics, tissue distribution and excretion of a novel platinum anticancer agent in rats by Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

Abstract 1. DN604 is a new platinum agent with encouraging anticancer activity. The present study was to explore the pharmacokinetic profiles, distribution and excretion of platinum in Sprague–Dawley rats after intravenous administration of DN604. A sensitive and selective inductively coupled plasma mass spectrometry (ICP-MS) method was established for determination of platinum in biological specimens. The pharmacokinetic parameters were calculated by a non-compartmental method. 2. The area under concentration–time curve AUC0−t and AUC0−∞ for platinum originating from DN604 at 10 mg/kg were 25.15 ± 1.29 and 28.72 ± 1.04 μg/hml, respectively. The mean residence time MRT was 36.59 ± 6.65 h. The volume of distribution Vz was 11.42 ± 2.49 l/kg and clearance CL was 0.18 ± 0.01 l/h/kg. In addition, the elimination half-life T1/2z was 44.83 ± 9.75 h. After intravenous administration of DN604, platinum was extensively distributed in most of tested tissues except brain. The majority of platinum excreted via urine, and its accumulative excretion ratio during the period of 120 h was 63.5% ± 7.7% for urine, but only 6.94% ± 0.11% for feces. 3. The satisfactory half-life, wide distribution and high excretion made this novel platinum agent worthy of further research and development.

Co-delivery of docetaxel and palmitoyl ascorbate by liposome for enhanced synergistic antitumor efficacy

Palmitoyl ascorbate (PA) as an antioxidant has the potential for the treatment of cancer. In the present study, a nanocarrier system was developed for co-delivery of docetaxel (DOC) with palmitoyl ascorbate and the therapeutic efficacy of a combination drug regimen was investigated. For this purpose, different ratios of docetaxel and palmitoyl ascorbate were co-encapsulated in a liposome and they all showed high encapsulation efficiency. The average diameters of the liposomes ranged from 140 to 170 nm. Negative zeta potential values were observed for all systems, ranged from −40 mV to −56 mV. Studies on drug release and cellular uptake of the co-delivery system demonstrated that both drugs were effectively taken up by the cells and released slowly. Moreover, the liposome loading drugs with DOC/PA concentration ratio of 1:200 showed the highest anti-tumor activity to three different types of tumor cells. The higher in vivo therapeutic efficacy with lower systemic toxicity of the DOC-PA200-LPs was also verified by the H22 tumor bearing mice model. Our results showed that such co-loaded delivery systems could serve as a promising therapeutic approach to improve clinical outcomes against hepatic carcinoma.

Trace quantification of 1-triacontanol in beagle plasma by GC-MS/MS and its application to a pharmacokinetic study.

1-Triacontanol (TA), a member of long chain fatty alcohol, has recently been received great attention owing to its antitumor activity. In this study, an accurate, sensitive and selective gas chromatography-tandem mass spectrometry method was developed and validated for the quantification of TA in beagle plasma using 1-octacosanal as the internal standard (IS) for the first time. With temperature programming, chromatographic separation was carried out on an HP-5MS column, using helium as carrier gas and argon as collision gas, both at a flow rate of 1 mL/min. TA was analyzed using positive ion electrospray ionization in multiple-reaction monitoring mode, with the precursor to product ion transitions of m/z 495.6 → 97.0 and m/z 467.5 → 97.0 for TA and the IS, respectively. The lower limit of quantitation, linearity, intra- and interday precision, accuracy, stability, extraction recovery and matrix effect of TA were within the acceptable limits. The validated method was successfully applied to a pharmacokinetic study of TA in beagles.

Epigallocatechin-3-gallate decreases the transport and metabolism of simvastatin in rats

Abstract 1. This study aimed to investigate the potential impact of epigallocatechin-3-gallate (EGCG) on the pharmacokinetic behaviors of simvastatin and its metabolite simvastatin acid and explored the possible role of metabolizing enzymes and transporters of this food–drug interaction. 2. Female SD rats were intravenously administered with EGCG (5 mg/kg), ketoconazole (10 mg/kg) and rifampin (10 mg/kg), followed by intravenous administration of 2 mg/kg simvastatin. In vitro, the effects of EGCG on Cytochrome P450 enzymes (CYP450) and organic anion transporting polypeptides (OATPs) were studied using human hepatic microsomes and human embryonic kidney 293 (HEK293) cells overexpressing OATP1B1 or OATP1B3. The results showed that areas under concentration–time (AUC) curves of simvastatin and simvastatin acid increased by 2.21- and 1.4-fold while the clearance was reduced by 2.29- and 1.4-fold, respectively, when co-administered with EGCG. In vitro experiments suggested the inhibitory effect of EGCG on CYP enzymes (IC50: 18.37 ± 1.36 μM, 26.08 ± 1.51 μM for simvastatin and simvastatin acid, respectively). Simvastatin transport by OATP1B1 and OATP1B3 was also inhibited by EGCG (IC50: 8.68 ± 1.27 μM and 22.67 ± 1.42 μM, respectively). 3. The presently reported novel food–drug interaction between EGCG and simvastatin involves the inhibition of not only CYP450 enzymes but also OATPs by EGCG.

Investigation on pharmacokinetics, tissue distribution and excretion of 1-triacontanol in rats by gas chromatography-tandem mass spectrometry (GC-MS/MS)

Abstract 1. 1-Triacontanol (TA) recently shows promising anti-tumor activity. The present study was aimed to develop a sensitive gas chromatography-tandem mass spectrometry method to explore the pharmacokinetic profiles, distribution and excretion of TA in Sprague-Dawley rats after oral administration of TA. Chromatography separation was performed on a HP-5MS column. 1-Octacosanal was used as the internal standard (IS). Quantification of TA and IS was carried out at m/z 495.6 → 97.0 and m/z 467.5 → 97.0, respectively, in positive electron ionization and multiple reaction monitoring mode. The pharmacokinetic parameters were calculated by non-compartmental analysis. 2. The area under concentration-time curve AUC0–6 h and AUC0–∞ for TA at 60 mg/kg were 87.737±13.574 and 93.617±17.62, respectively. The mean residence time was 3.25 ± 0.17 h. In addition, the elimination half-lives (t1/2) were (2.37±1.23, 1.27±0.49, 2.07±0.93) h after single oral administration of 30, 60 and 120 mg/kg of TA. After oral administration, TA was extensively distributed in stomach and intestine. The majority of TA excreted via feces, and its accumulative excretion ratio during the period of 72 h was 26.68 ± 7.14%, but only 0.0023 ± 0.0015% and 0.0027 ± 0.0006% for urines and bile, respectively. The absolute bioavailability (F, %) of TA was about 2.0%.

Effect of triacontanol on the pharmacokinetics of docetaxel in rats associated with induction of cytochrome P450 3A1/2

Abstract 1. Triacontanol was confirmed to have a potential anti-cancer effect, the aim was to assess whether the co-administration of triacontanol alters the exposure of docetaxel via inducing hepatic CYP3A1/2 activity. The concentration of docetaxel in rats pretreated with triacontanol for seven successive days was determined, and the expression levels of CYP3A protein and mRNA were analyzed by the western blot and real time polymerase chain reaction (RT-PCR) technique, respectively. 2. The concentrations of docetaxel in rats pretreated with triacontanol were decreased, with 61.5%, 61.9% decrease in AUC0–24h and 65.7%, 54.9% reduction in Cmax (120 and 180 mg kg−1, respectively) compared with the control. Hepatic clearance of docetaxel was enhanced in vitro and in vivo at dosage of 120 and 180 mg kg−1, and CYP3A activity was up-regulated by measuring the formation rate of 1-hydroxymidazolam. Triacontanol preferentially induced protein expression level of CYP3A2 in a dose-dependent manner and of CYP 3A1 at dosage of 120 and 180 mg kg−1. The mRNA expression of CYP3A1 was moderately different with the western blot results, but the trends appeared similar. CYP3A2 mRNA level was not markedly affected by triacontanol. 3. The significant triacontanol–docetaxel interaction was largely due to the induction of CYP3A1/2, which brought useful information in the clinical therapy when the combination is administered in human.

Evaluation of the pharmacokinetics, tissue distribution and excretion studies of YMR-65, a tubulin polymerization inhibitor with potential anticancer activity, in rats using UPLC-MS/MS

Abstract 1. YMR-65, 5-(5-bromo-1-methyl-1H-indol-3-yl)-3-(3-methoxyphenyl)-4, 5-dihydro-1H-pyrazole-1-carboxamide, is a new tubulin polymerization inhibitor with encouraging anticancer activity. 2. The validated ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) method was successfully applied to the pharmacokinetics, tissue distribution and excretion study of YMR-65 after oral and intravenous administration. The area under concentration-time curve (AUC0-∞) for YMR-65 were 151.67 ± 54.48 and 459.45 ± 49.23 ng/ml*h for oral and intravenous administration at the dosage of 1.5 mg/kg, respectively and the oral bioavailability was about 33.01%. Moreover, YMR-65 was extensively distributed in heart, liver, spleen, lung, kidney, stomach, intestine and testis and the highest were detected in heart, followed by stomach, intestine and liver. The majority of YMR-65 was excreted via feces and its accumulative excretion ratio during the period of 96 h was 19.83 ± 3.01%, but only 1.54 ± 0.37 and 0.215 ± 0.026% for urine within 96 h and bile within 10 h after intravenous administration, respectively, though the fecal and urine excretion were incomplete within 96 h. 3. In summary, this study defined the pharmacokinetic characteristics of YMR-65 in vivo and the important data can be a useful resource for further research and development.

Hydrophilic interaction liquid chromatography-tandem mass spectrometry method for the determination of intact oxaliplatin in cells: validated and applied in colon cancer HCT-116 cell line

HIGHLIGHTSA novel sensitive HILIC‐MS/MS method was developed for quantification of intact oxaliplatin in cells for the first time.The method was fully validated and provided increased selectivity, sensitivity and high throughput.The uptake of intact oxaliplatin by HCT‐116 cell line was described successfully.Our findings may prospectively support low concentration measurement of intact oxaliplatin in the clinic. ABSTRACT Oxaliplatin is a platinum compound that is frequently prescribed for the chemotherapeutic treatment of colorectal cancer. In tumor cells, cellular uptake is the first step of oxaliplatin action. Cellular accumulation of oxaliplatin is considered to play an important role in anti‐cancer efficacy. However, limited information about cellular accumulation of intact oxaliplatin is available. In this study, a sensitive hydrophilic interaction liquid chromatography‐tandem mass spectrometry (HILIC‐MS/MS) approach for the quantification of oxaliplatin in cells was developed and validated. The method allowed for a rapid and simple determination of intact oxaliplatin in cell lysate. The retention time of oxaliplatin was 3.04min, which was achieved by applying a chromatographic gradient elution of 5min. The lower limit of quantification (LLOQ) was 2ng/mL and the analytical range of oxaliplatin was linear between 2–200ng/mL. The intra‐day precision and inter‐day precision (RSD (relative standard deviation)) ranged from 0.52 to 7.89%, and the accuracy (RE (relative error)) was within±4.5%. Matrix effects and recovery were acceptable. The method was successfully used for the determination of intact oxaliplatin uptake by HCT‐116 colon cancer cells. Thus, our findings may prospectively support a celluar pharmacokinetic study and low concentration measurement of intact oxaliplatin in the clinic.

Determination of oroxylin A and oroxylin A 7-O-d-glucuronide in HepG2 cell lysate and subcellular fractions with SPE-UPLC–MS/MS: Cellular pharmacokinetic study to indicate anti-cancer mechanisms

HIGHLIGHTSA SPE‐UPLC–MS/MS method was proposed in HepG2 cell lysate and subcellular fractions.The validated method showed high accuracy, specificity and sensitivity for OA and OG.High sensitivity is represented by the LLOQ at 0.5nM in subcellular organelles.OA and OG mainly distributed into nuclei.OG redistributed into mitochondria and cytoplasm. ABSTRACT Targeting therapy of anti‐cancer drugs has been gaining increasing attention. Cell pharmacokinetics have been used for in vitro disposition evaluation, as well as drug–drug interaction for anti‐cancer drugs, revealing their fate after entering tumor. Flavonoid compound oroxylin A (OA) possesses strong anti‐cancer effects especially on the liver and breast cancer. However, despite the low bioavailability, the disposition of OA and its active metabolite in the target cancer cells remained unclear. In current study, a highly sensitive and selective solid phase extraction (SPE)‐UPLC–MS/MS method was developed and validated to simultaneously quantify the concentrations of OA and its major active metabolite oroxylin A 7‐O‐d‐glucuronide (OG) in HepG2 cell lysate and multiple subcellular organelle fractions. The proposed method appeared to be suitable for the analysis with desirable linearity(R2>0.99). The relative standard deviations (RSDs) of intra‐ and inter‐assay precision and accuracy were less than 9.9% and −7.7%, 8.4% and 11% for OA and OG in cell lysate respectively. The intra‐ precision and accuracy was less than 9.5% and −11.3%, 9.4% and 12.3% for OA and OG in subcellular organelles respectively. The range of absolute recovery of this method in the cell lysate was from 73.1%±1.4% to 87.9%±6.7%. The RSDs of matrix effects of the quality control (QC) samples were below 15%. The uptake and distribution experiments demonstrated a time‐dependent transport characteristic in HepG2 cell lines. Furthermore, both OA and OG were mainly distributed into nuclei after taken up by the tumor cells. In addition, OG was also distributed into mitochondria, which indicates another potential target of OG. The present study, for the first time, reports the in vitro cell pharmacokinetics profiles of OA and OG in tumor cell lines in vitro.