Quantitative determination of puerarin in dog plasma by HPLC and study on the relative bioavailability of sustained release tablets

Comparative Pharmacokinetics of Puerarin Alone and in Pueraria mirifica Extract in Female Cynomolgus Monkeys

Pueraria mirifica is an endemic Thai plant that has been used for rejuvenation and in the relief of various aging diseases. Puerarin is one of the major isoflavones found in this plant and shows several pharmacological activities in relation to the Thai traditional use of P. mirifica. Therefore, comparative pharmacokinetics of pure puerarin alone and that in a P. mirifica extract in cynomolgus monkeys were conducted in order to investigate the pharmacokinetic profiles of the 2 preparations. To this end, puerarin and P. mirifica extract, at an equivalent dose of 10 mg/kg of puerarin, were orally dosed to adult female monkeys for 7 consecutive days. A single intravenous injection of puerarin at a dose of 1 mg/kg was also peformed. Serial blood samples and excreta were collected from 0 - 24 h and 0 - 48 h after dosing. Determination of the puerarin levels and its metabolites in biological samples was conducted by liquid chromatography tandem mass spectrometry. Plasma levels of aspartate aminotransferase, alanine aminotransferase, and creatinine fluctuated in the normal range, with no abnormal physical signs in the animal. The absolute oral bioavailability of puerarin was approximately 1% in both preparations. Accumulation of puerarin was found after oral dosing for 7 consecutive days in both groups. Major metabolites of puerarin found in monkeys were hydroxylation and deglycosylation products. A negligible amount of unchanged puerarin was detected in urine and feces. Pharmacokinetic profiles obtained from this study could help to design the prescribed remedy of puerarin and P. mirifica extract phytopharmaceutical products for human use.

Absolute oral bioavailability and disposition kinetics of puerarin in female rats

Background

Pueraria candollei var. mirifica is a medicinal plant that is promoted as a “Champion Product” by the Government of Thailand. This plant has been reported to relieve postmenopausal symptoms, prevent and reverse bone loss, inhibit the growth of breast cancer, and alleviate cardiovascular diseases in preclinical and clinical studies. However, there is little information on the oral bioavailability and tissue distribution of puerarin with respect to its pharmacodynamic activities. Therefore, the aim of this study was to determine the pharmacokinetics of puerarin, including absorption, distribution, metabolism, and elimination, in rats. Moreover, this is the first study to examine the tissue distribution of puerarin in the hippocampus, femur, tibia, and mammary gland.

Methods

Adult female rats were administered puerarin at 1 mg/kg intravenously or 5 and 10 mg/kg orally. Blood, tissue, urine, and feces were collected and analyzed by liquid chromatography–tandem mass spectrometry.

Results

Puerarin reached a maximum concentration in the blood of 140–230 μg/L within 1 h of oral dosing, and had an absolute oral bioavailability of approximately 7%. Following intravenous administration, puerarin was widely distributed in several tissues, including the hippocampus, heart, lung, stomach, liver, mammary gland, kidney, spleen, femur, and tibia. Approximately 50% of the intravenous dose was excreted as glucuronide metabolites via the urinary route.

Conclusions

The absolute oral bioavailability of puerarin was approximately 7% at doses of 5 and 10 mg/kg. Puerarin was widely distributed to several organs related to the diseases of aging, including the hippocampus, femur, tibia, and mammary gland. Glucuronides were the major metabolites of puerarin and were mainly excreted in the urine. These results are useful for the development of puerarin and Pueraria candollei var. mirifica as phytopharmaceutical products.

The Occurrence, Fate and Biological Activities of C-glycosyl Flavonoids in the Human Diet

The human diet contains a wide variety of plant-derived flavonoids, many of which are glycosylated via an O- or less commonly a C-glycosidic linkage. The distribution, quantity, and biological effects of C-glycosyl flavonoids in the human diet have received little attention in the literature in comparison to their O-linked counterparts, however, despite being present in many common foodstuffs. The structural nature, nomenclature, and distribution of C-glycosyl flavonoids in the human diet are, therefore, reviewed. Forty-three dietary flavonoids are revealed to be C-glycosylated, arising from the dihydrochalcone, flavone, and flavan-3-ol backbones, and distributed among edible fruits, cereals, leaves, and stems. C-linked sugar groups are shown to include arabinose, galactose, glucose, rutinose, and xylose, often being present more than once on a single flavonoid backbone and occasionally in tandem with O-linked glucose or rutinose groups. The pharmacokinetic fate of these compounds is discussed with particular reference to their apparent lack of interaction with hydrolytic mechanisms known to influence the fate of O-glycosylated dietary flavonoids, explaining the unusual but potentially important appearance of intact C-glycosylated flavonoid metabolites in human urine following oral administration. Finally, the potential biological significance of these compounds is reviewed, describing mechanisms of antidiabetic, antiinflammatory, anxiolytic, antispasmodic, and hepatoprotective effects.

Simultaneous determination of acetylpuerarin and puerarin in rat plasma by liquid chromatography-tandem mass spectrometry: Application to a pharmacokinetic study following intravenous and oral administration

A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the simultaneous determination of acetylpuerarin (AP) and its major metabolite puerarin (PUE) in rat plasma using genistein as the internal standard (IS). Plasma samples were pretreated by protein precipitation with a mixture of methanol and acetonitrile. Chromatographic separation was performed on a CAPCELL PAK C18 MGШ column with a mixture of 0.1% formic acid in water and methanol (35:65, v/v) as the mobile phase. The analytes were detected using a tandem mass spectrometer in the positive ionization and multiple-reaction monitoring mode. The ion transition of m/z 669.4→627.3, 417.5→297.6 and 271.3→153.0 was utilized to quantify AP, PUE and the IS, respectively. The calibration curves showed good linearity over the plasma concentration range of 1-2000ng/mL for AP and 2.5-5000ng/mL for PUE. The intra- and inter-day precisions (RSD %) for each analyte were less than 6.91%, and the accuracies ranged from -2.17% to 2.93%. The validated LC-MS/MS method was further successfully applied to a pharmacokinetic study of AP and PUE in rats following intravenous and oral administration.

Comparative pharmacokinetics of puerarin, daidzin, baicalin, glycyrrhizic acid, liquiritin, berberine, palmatine and jateorhizine by liquid chromatography-mass spectrometry after oral administration of Gegenqinlian decoction and active components alignment (ACA) to rats

An LC-MS/MS method was developed for simultaneous analysis of puerarin, daidzin, baicalin, glycyrrhizic acid, liquiritin, berberine, palmatine and jateorhizine of Gegenqinlian Decoction (GQD) and active components alignment (ACA) in rat plasma using hesperidin as the internal standard (I.S.). Chromatography was performed using a C18 column, with gradient elution with 1% acetic acid-0.001 mol/L ammonium acetate and acetonitrile at 0.2 ml/min. All analytes including I.S. were monitored under positive ionization conditions by selected reaction monitoring with an electrospray ionization source. The optimized mass transition ion-pairs (m/z) for quantitation were 471/297 for puerarin, 471/255 for daidzin, 447/271 for baicalin, 823/453 for glycyrrhizic acid, 419/257 for liquiritin, 336/320 for berberine, 352/336 for palmatine, 338/322 for jateorhizine and 611/303 for hesperidin. The calibration curves were linear over the concentration ranges from 0.15-63.0 to 6.3-6340.0 ng/mL. Intra-day and inter-day precisions (RSD%) were within 15.0%, and accuracy (RE%) ranged from -7.4 to 13.2%. The extraction recoveries were ranged from 60.4 to 93.3%. The proposed method was further applied to compare the pharmacokinetics of all analytes following a single oral administration of GQD and ACA. In conclusion, the eight analytes of GQD and ACA had partly similar pharmacokinetics, which were different from single composition (such as puerarin).

Simultaneous determination of puerarin and its active metabolite in human plasma by UPLC-MS/MS: application to a pharmacokinetic study

A rapid, selective and sensitive ultra-performance liquid chromatography (UPLC)-tandem mass spectrometry method about the simultaneous determination of puerarin and its major active metabolite, daidzein, in human plasma was developed and validated in order to investigate the pharmacokinetics (PKs) of Gegen after the usual oral dose administration to human. Chromatography was carried out on a Kinetex C18 column (2.1mm×50mm, 1.7μm) using 0.05% acetic acid in water and 0.05% acetic acid in methanol as mobile phase with a gradient elution. Liquid-liquid extraction with ethyl acetate in acidic condition could remove the interference and minimize the matrix effect of human plasma. The lower limit of quantification in human plasma was 0.2ng/mL for both of compounds, puerarin and daidzein. The calibration curves for puerarin and daidzein in human plasma were linear over all the concentration range of 0.2-100ng/mL with correlation coefficients greater than 0.998. This assay procedure was successfully applied to the PKs of puerarin and daidzein, after the usual oral dose of Gegen extract powder (2.56g, containing 9.984mg puerarin) in human subjects.

Biotransformation of puerarin into puerarin-6″-O-phosphate by Bacillus cereus

The biotransformation of puerarin catalyzed by Bacillus cereus NT02 was studied. A primary screening was carried out using 307 strains of bacteria isolated from soil which were able to grow in the presence of puerarin. Strain NT02, identified as B. cereus, was able to convert puerarin into puerarin-6″-O-phosphate. Under the optimum conditions, resting cells of B. cereus NT02 converted 27% of added 0.4 g/l puerarin into puerarin-6″-O-phosphate that was characterized by MS, 13C NMR, 31P NMR. The activity of puerarin-6″-O-phosphate was 25 times higher than that of puerarin in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging system. The water solubility of puerarin-6″-O-phosphate was 85.4 times higher than that of puerarin.

Determination of puerarin in rabbit aqueous humor by liquid chromatography tandem mass spectrometry using microdialysis sampling after topical administration of puerarin PAMAM dendrimer complex

To study pharmacokinetic properties of puerarin poly(amido amine) (PAMAM) dendrimer complex, a sensitive liquid chromatography tandem mass spectrometry method (LC-MS/MS) was developed and validated to determine puerarin in rabbit aqueous humor using microdialysis sampling. Astilbin was used as the internal standard. The linear range for puerarin was from 2 to 1000ng/mL (r=0.9986) based on 20μL of aqueous humor. The coefficients of variations for intra-day and inter-day precisions were less than 10.0%, and the relative error of accuracy was within ±6.3%. The mean extraction recovery of puerarin varied from 80.4% to 85.5%. Microdialysis provides a complete concentration versus time profile. A significant difference was observed in main pharmacokinetic parameters of C(max), AUC and t(1/2) between puerarin solution and puerarin PAMAM dendrimer complex. Complex formation resulted in an obvious increase in bioavailability of puerarin after topical administration to rabbit according to the above LC-MS/MS assay method.

New perspectives on chinese herbal medicine (zhong-yao) research and development

Synthetic chemical drugs, while being efficacious in the clinical management of many diseases, are often associated with undesirable side effects in patients. It is now clear that the need of therapeutic intervention in many clinical conditions cannot be satisfactorily met by synthetic chemical drugs. Since the research and development of new chemical drugs remain time-consuming, capital-intensive and risky, much effort has been put in the search for alternative routes for drug discovery in China. This narrative review illustrates various approaches to the research and drug discovery in Chinese herbal medicine. Although this article focuses on Chinese traditional drugs, it is also conducive to the development of other traditional remedies and innovative drug discovery.

Characterization and selectivity studies of molecular imprinted membranes of Puerarin using scanning electron microscopy

Molecular-imprinted membranes of Puerarin were prepared by phase inversion technique with acrylonitrile-acrylic acid copolymer (P (AN-co-AA)). To characterize P (AN-co-AA), ubbelohde viscometer was used to measure its viscosity-molecular weight. P (AN-co-AA) with different molecular weight was used to prepare membranes. The copolymer-dimethyl sulfoxide solution with Puerarin (PU) template was coagulated in water at various temperatures. The increase in P (AN-co-AA) molecular weight and the decrease in coagulation temperature caused an increase in PU recognition property of the resultant membrane. The PU imprinted membrane prepared with P (AN-co-AA) showed good selective ability to PU. The purity of PU increased from 56.51 to 98.41 wt%. Surface and cross-section morphology of the membranes were analyzed by using scanning electron micrograph. High-performance liquid chromatography was used for the quantification of Puerarin in isolated fraction.

Pharmacokinetic comparison of puerarin after oral administration of Jiawei-Xiaoyao-San to healthy volunteers and patients with functional dyspepsia: influence of disease state

Objectives

An investigation has been designed and conducted to compare the pharmaco-kinetics of puerarin after oral administration of Jiawei-Xiaoyao-San to healthy volunteers and to patients with functional dyspepsia.

Methods

Quantification of puerarin in serum was achieved using a simple and rapid HPLC method for pharmacokinetic study.

Key findings

After oral administration of decoctions of Jiawei-Xiaoyao-San to healthy volunteers and patients with functional dyspepsia, puerarin was absorbed and reached a maximum concentration of 56.47 ± 15.60 and 29.40 ± 8.89 ng/ml at 51.00 ± 8.22 and 50.00 ± 12.25 min, respectively. Compared with the value of AUC0–360 (5.55 ± 1.47 μg/ml min) in healthy volunteers, a smaller value of AUC0–360 (3.35 ± 1.17 μg/ml min) was observed in patients with functional dyspepsia.

Conclusions

There were statistically significant differences in the pharmacokinetic parameters of puerarin including the values for Cmax, AUC0–360, Cl/F and MRT0–360 between healthy volunteers and patients with functional dyspepsia. The pharmacokinetic parameters showed that functional dyspepsia reduced the absorption of puerarin after oral administration of Jiawei-Xiaoyao-San.

Pharmacokinetic study of puerarin in rat serum by liquid chromatography tandem mass spectrometry

A highly sensitive and specific atmospheric pressure chemical ionization liquid chromatography-tandem mass spectrometry method was developed for serum pharmacokinetic studies of puerarin in rats. Chromatography was carried out on a reversed-phase Phenomenex Synergi 4 microm Fusion-RP80 column (150 x 2.0 mm i.d.) using a mobile phase consisting of acetonitrile-water (10:90, v/v) in 10 mm NH(4)OAc with a flow rate of 0.2 mL/min. Puerarin was analyzed in the multiple reaction monitoring mode with a precursor/product ion transition of m/z 415/267. The method was demonstrated to be specific and sensitive, and a linear response was observed over a range of 2-5000 ng/mL in rat serum. The validated method was successfully applied to the characterization of the pharmacokinetics of puerarin in rat serum after oral administration to spontaneously hypertensive rats. The blood concentration-time profile of puerarin showed a rapid initial increase, reaching a maximum and then declining within 1 h. Puerarin could not be detected after 24 h. The main pharmacokinetic parameters for puerarin after oral administration were as follows: C(max) (3.54 +/- 2.03 mg/L), T(max) (0.68 +/- 0.37 h), AUC(0-t) (7.29 +/- 3.79 mg h/L), AUC(0-infinity) (9.17 +/- 4.87 mg h/L), T(1/2) (1.7 +/- 0.6 h), CL/F (7.24 +/- 4.27 L/h/kg) and V/F (17.88 +/- 13.55 L/h/kg).