Roles and mechanisms of puerarin on cardiovascular disease：A review.

Cardiovascular diseases (CVDs) are now the leading cause of mortality and morbidity worldwide，resulting in a large global economic burden. Recently, complementary and alternative medicine, such as traditional Chinese medicine (TCM) have received great attention. Puerarin (Pue) is an isoflavone isolated from the roots of Pueraria lobata (Willd.) Ohwi (also named "Ge gen" in China), and is a versatile TCM herb used for the treatment of fever, diarrhea, diabetes mellitus CVDs and cerebrovascular diseases. Numerous lines ofin vitro studies, as well as in vivo animal experiments have established that Pue offers beneficial roles against the progression of atherosclerosis, ischemic heart diseases, heart failure hypertension and arrhythmia by inhibiting pathological processes, such as the mitigation of endothelium injury, protection against inflammation, the disturbance of lipid metabolism, protection against ischemic reperfusion injury, anti-myocardial remodeling and other effects. Here, we provide a systematic overview of the pharmacological actions and molecular targets of Pue in cardiovascular disease prevention and treatment, to provide insights into the therapeutic potential of Pue in treating cardiovascular diseases.

Simultaneous quantification and rat pharmacokinetics of formononetin-7-O-ß-d-glucoside and its metabolite formononetin by high-performance liquid chromatography-tandem mass spectrometry.

Formononetin-7-O-ß-d-glucoside has been proved to have significant anti-inflammatory effect. To evaluate its rat pharmacokinetics, a rapid, sensitive, and specific liquid chromatography-tandem mass spectrometry method has been developed and validated for the quantification of formononetin-7-O-ß-d-glucoside and its main metabolite formononetin in rat plasma. Samples were pretreated using a simple protein precipitation and the chromatographic separation was performed on a C18 column by a gradient elution using a mobile phase consisting of water and acetonitrile both containing 0.1% formic acid. Both analytes were detected using a tandem mass spectrometer in positive multiple reaction monitoring mode. The assay showed wide linear dynamic ranges of both 0.10-100 ng/mL, with acceptable intra- and inter-batch accuracy and precision. The lower limits of quantification were both 0.10 ng/mL using 50 µL of rat plasma for two analytes. The method has been successfully used to investigate the oral pharmacokinetic profiles of both analytes in rats. After oral administration of formononetin-7-O-ß-d-glucoside at the dose of 50 mg/kg, it was rapidly absorbed in vivo and metabolized to its metabolite formononetin. The plasma concentration-time profiles both showed double-peak phenomena, which would be attributed to the strong enterohepatic circulation of formononetin-7-O-ß-d-glucoside.

Effects of puerarin on the pharmacokinetics of astragaloside IV in rats and its potential mechanism.

Context: Puerarin and astragaloside IV (AS-IV) are sometimes used together for the treatment of disease in Chinese clinics, however, the drug-drug interaction between puerarin and AS-IV is still unknown.Objective: This study investigates the effects of puerarin on the pharmacokinetics of astragaloside IV in rats and clarifies its main mechanism.Materials and methods: The pharmacokinetic profiles of oral administration of astragaloside IV (20 mg/kg) in Sprague-Dawley rats, with or without pre-treatment of puerarin (100 mg/kg/day for 7 days) were investigated. The effects of puerarin on the transport and metabolic stability of AS-IV were also investigated using Caco-2 cell transwell model and rat liver microsomes.Results: The results showed that puerarin could significantly increase the peak plasma concentration (from 48.58 ± 7.26 to 72.71 ± 0.62 ng/mL), and decrease the oral clearance (from 47.5 ± 8.91 to 27.15 ± 9.27 L/h/kg) of AS-IV. The Caco-2 cell transwell experiments indicated that puerarin could decrease the efflux ratio of astragaloside IV from 1.89 to 1.26, and the intrinsic clearance rate of astragaloside IV was decreased by the pre-treatment with puerarin (34.8 ± 2.9 vs. 41.5 ± 3.8 µL/min/mg protein).Discussion and conclusions: These results indicated that puerarin could significantly change the pharmacokinetic profiles of astragaloside IV, via increasing the absorption of astragaloside IV or inhibiting the metabolism of astragaloside IV in rats.

Pharmacokinetics, Tissue Distribution, and Druggability Prediction of the Natural Anticancer Active Compound Cytisine N-Isoflavones Combined with Computer Simulation.

Cytisine N-methylene-(5,7-dihydroxy-4'-methoxy)-isoflavone (CNF2) is a new compound isolated from the Chinese herbal medicine Sophora alopecuroides. Preliminary pharmacodynamic studies demonstrated its activity in inhibiting breast cancer cell metastasis. This study examined the pharmacokinetics, absolute bioavailability, and tissue distribution of CNF2 in rats, and combined computer-aided technology to predict the druggability of CNF2. The binding site of CNF2 and the breast cancer target human epidermal growth factor receptor-2 (HER2) were examined with molecular docking technology. Next, ACD/Percepta software was used to predict the druggability of CNF2 based on the quantitative structure-activity relationship (QSAR). Finally, a simple and effective HPLC method was used to determine plasma pharmacokinetics and tissue distribution of CNF2 in rats. Prediction and experimental results show that compared with the positive control HER2 inhibitor SYR127063, CNF2 has a stronger binding affinity with HER2, suggesting that its efficacy is stronger; and the structure of CNF2 complies with the Lipinski's Rule of Five and has good drug-likeness. The residence time of CNF2 in rats is less than 4 h, and the metabolic rate is relatively fast; But the absolute bioavailability of CNF2 in rats was 6.6%, mainly distributed in the stomach, intestine, and lung tissues, where the CNF2 contents were 401.20, 144.01, and 245.82 µg/g, respectively. This study constructed rapid screening and preliminary evaluation of active compounds, which provided important references for the development and further research of such compounds.

Enrichment of Polyglucosylated Isoflavones from Soybean Isoflavone Aglycones Using Optimized Amylosucrase Transglycosylation.

Isoflavones in soybeans are well-known phytoestrogens. Soy isoflavones present in conjugated forms are converted to aglycone forms during processing and storage. Isoflavone aglycones (IFAs) of soybeans in human diets have poor solubility in water, resulting in low bioavailability and bioactivity. Enzyme-mediated glycosylation is an efficient and environmentally friendly way to modify the physicochemical properties of soy IFAs. In this study, we determined the optimal reaction conditions for Deinococcus geothermalis amylosucrase-mediated α-1,4 glycosylation of IFA-rich soybean extract to improve the bioaccessibility of IFAs. The conversion yields of soy IFAs were in decreasing order as follows: genistein > daidzein > glycitein. An enzyme quantity of 5 U and donor:acceptor ratios of 1000:1 (glycitein) and 400:1 (daidzein and genistein) resulted in high conversion yield (average 95.7%). These optimal reaction conditions for transglycosylation can be used to obtain transglycosylated IFA-rich functional ingredients from soybeans.

LC-MS/MS analysis of puerarin and 18ß-glycyrrhetinic acid in human plasma after oral administration of Samso-eum and its application to pharmacokinetic study.

The aim of this study was to confirm pharmacokinetic screening of multiple components in healthy Korean subjects after oral administration of Samso-eum and perform quantitation of active components in the human plasma. Thirteen potential bioactive components [puerarin (PRR), daidzin, nodakenin, ginsenoside Rb1, 18ß-glycyrrhetinic acid (18ß-GTA), 6-shogaol, naringin, glycyrrhizin, hesperidin, platycodin D, naringenin, hesperetin, and 6-gingerol] were screened based on literature. The results showed that three analytes (daidzin, naringenin, and hesperetin) were detected in trace amounts. In addition, PRR and 18ß-GTA were detected in human plasma after the oral administration of Samso-eum. In this study, a liquid chromatography-electrospray ionization-tandem mass spectrometry method was validated for the simultaneous determination of PRR and 18ß-GTA in human plasma. This was the first study to evaluate pharmacokinetics of PRR and 18ß-GTA after the usual oral dose of Samso-eum (30 g containing 102.48 mg PRR, 48.18 mg glycyrrhizin) in human subjects.

An ultra high performance liquid chromatography with tandem mass spectrometry method for simultaneous determination of thirteen components extracted from Radix Puerariae in rat plasma and tissues: Application to pharmacokinetic and tissue distribution study.

A rapid and sensitive ultra high performance liquid chromatography with tandem mass spectrometry method was established and validated for simultaneous determination of thirteen bioactive components (gallic acid, protocatechuic acid, puerarin, p-hydroxycinnamic acid, daidzin, ononin, daidzein, naringenin, genistein, apigenin, formononetin, biochanin A, and ß-sitosterol) of Radix Puerariae extract in rat plasma and tissues. The plasma and tissues samples were pretreated by protein precipitation extraction, and umbelliferone and rutin were used as internal standards. Sample separation was performed on a ZORBAX RRHD Eclipse plus C18 column (2.1 mm × 50 mm, 1.8 µm, Agilent) with a mobile phase consisting of methanol-water (containing 0.1% formic acid). The mass spectrometry analysis was conducted in positive and negative ionization modes with multiple reaction monitoring. The lower limit of quantitation range for the 13 analytes was 0.2-35 ng/mL. The intra- and inter-day precision of all the analytes were less than 10.92%, with an accuracy ranging from -13.10 to 11.96%. Both the recovery and matrix effect were within acceptable limits. This method was successfully applied to pharmacokinetic and tissue distribution study of the 13 bioactive components in rats after oral administration of R. Puerariae extract.

Nanoparticles Mediating the Sustained Puerarin Release Facilitate Improved Brain Delivery to Treat Parkinson's Disease.

Recent work has highlighted the potential of puerarin (PU) as a valuable compound to treat Parkinson's disease (PD), but its undesirable water solubility and bioavailability have constrained its utility. In this study, we sought to develop nanoparticles (NPs) that could be used to encapsulate PU, thereby extending its in vivo half-life and improving its bioavailability and accumulation in the brain to treat the symptoms of PD. We prepared spherical NPs (88.36 ± 1.67 nm) from six-armed star-shaped poly(lactide-co-glycolide) (6-s-PLGA) NPs that were used to encapsulate PU (PU-NPs) with 89.52 ± 1.74% encapsulation efficiency, 42.97 ± 1.58% drug loading, and a 48 h sustained drug release. NP formation and drug loading were largely mediated by hydrophobic interactions, while changes in the external environment led these NPs to become increasingly hydrophilic, thereby leading to drug release. Relative to PU alone, PU-NPs exhibited significantly improved cellular internalization, permeation, and neuroprotective effects. Upon the basis of Förster resonance energy transfer (FRET) of NPs-administered zebrafish, we were able to determine that these NPs were rapidly absorbed into circulation whereupon they were able to access the brain. We further conducted oral PU-NPs administration to rats, revealing significant improvements in PU accumulation within the plasma and brain relative to rats administered free PU. In MPTP-mediated neurotoxicity in mice, we found that PU-NPs treatment improved disease-associated behavioral deficits and depletion of dopamine and its metabolites. These findings indicated that PU-NPs represent a potentially viable approach to enhancing PU oral absorption, thus improving its delivery to the brain wherein it can aid in the treatment of PD.

Pharmacokinetics and drug delivery systems for puerarin, a bioactive flavone from traditional Chinese medicine.

Pueraria lobata (Willd.) Ohwi is a medicinal and edible homologous plant with a long history in China. Puerarin, the main component isolated from the root of Pueraria lobata, possesses a wide range of pharmacological properties. Daidzein and glucuronides are the main metabolites of puerarin and are excreted in the urine and feces. As active substrates of P-gp, multidrug resistance-associated protein and multiple metabolic enzymes, the pharmacokinetics of puerarin can be influenced by different pathological conditions and drug-drug interactions. Due to the poor water-solubility and liposolubility, the applications of puerarin are limited. So far, only puerarin injections and eye drops are on the market. Recent years, researches on improving the bioavailability of puerarin are developing rapidly, various nanotechnologies and preparation technologies including microemulsions and SMEDDS, dendrimers, nanoparticles and nanocrystals have been researched to improve the bioavailability of puerarin. In order to achieve biocompatibility and desired activity, more effective quality evaluations of nanocarriers are required. In this review, we summarize the pharmacokinetics and drug delivery systems of puerarin up to date.

Simultaneous determination of eight constituents in rat plasma by HPLC-MS/MS and its application to a pharmacokinetic study after oral administration of Shejin-liyan Granule.

Shejin-liyan Granule (SJLY) is an effective traditional Chinese prescription medicine for the treatment of acute pharyngitis. In this study, a selective and convenient HPLC-MS/MS method was developed and validated for the simultaneous determination of the following eight constituents in the plasma: galuteolin, tectoridin, tectorigenin, iridin, irigenin, irisflorentin, arctiin and arctigenin. The plasma samples were prepared by a protein precipitation method using acetonitrile, and analysis was carried out on a C18 column using a gradient elution at a flow rate of 0.3 mL/min. The concentration of these analytes was quantified in the positive ion and multiple reaction monitoring modes. The method was validated for selectivity, linearity, accuracy, precision, recovery, matrix effect and sample stability. The obtained results were well within the acceptable limits. The established method was then successfully applied to study the pharmacokinetic profiles of the multiple constituents of Shejin-liyan Granule. According to the area under the curve and maximum concentration data, tectorigenin exhibited the highest exposure followed by arctigenin, irigenin, arctiin and irisflorentin. The concentrations of galuteolin, tectoridin and iridin were low, and a complete concentration-time curve could not be plotted. This research provides useful information for understanding the pharmacokinetics of Shejin-liyan Granule.

A network pharmacology integrated pharmacokinetics strategy for uncovering pharmacological mechanism of compounds absorbed into the blood of Dan-Lou tablet on coronary heart disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Dan-Lou tablet (DLT) is developed from the traditional Chinese medicine (TCM) formula Gualou Xiebai Baijiu Tang which has been used for at least 2000 years in China. DLT has been widely used in clinical practice to treat cardiovascular diseases. AIM OF THE STUDY: This study aimed to uncover the pharmacological mechanism of the compounds absorbed into the blood of Dan-Lou tablet (DLT) on coronary heart disease (CHD) using a network pharmacology integrated pharmacokinetics strategy. MATERIALS AND METHODS: A rapid and sensitive method was developed for the simultaneous determination of the six compounds (puerarin, formononetin, calycosin, paeoniflorin, cryptotanshinone and tanshinone IIA) in rat plasma by liquid chromatography tandem mass spectrometry (LC-MS/MS). Then, the pharmacology network was established based on the relationship between five compounds absorbed into the blood targets (puerarin, formononetin, calycosin, cryptotanshinone and tanshinone IIA) and CHD targets. RESULTS: The intra-and inter-day precision were less than 11% and the accuracy ranged from 88.2% to 112%, which demonstrated that the LC-MS/MS method could be used to evaluate the pharmacokinetic feature of the six compounds in rats after oral administration of DLT. The pathway enrichment analysis revealed that the significant bioprocess networks of DLT on CHD were positive regulation of estradiol secretion, negative regulation of transcription from RNA polymerase II promoter, lipopolysaccharide-mediated signaling pathway and cytokine activity. CONCLUSION: The proposed network pharmacology integrated pharmacokinetics strategy provides a combination method to explore the therapeutic mechanism of the compounds absorbed into the blood of multi-component drugs on a systematic level.

Simultaneous determination of five isoflavones in rat plasma by LC-MS/MS: Comparative pharmacokinetic characteristics of Puerariae lobatae radix in normal and type 2 diabetic rats.

A rapid and sensitive liquid chromatography with tandem mass spectrometry method was developed and validated for simultaneous determination of puerarin, daidzin, daidzein, 3'-hydroxy puerarin, and genistein in rat plasma after oral administration of Puerariae lobatae radix extract. The method of protein precipitation with acetonitrile was used for sample preparation. Chromatographic separation was achieved on a C18 column with the mobile phases of acetonitrile/water containing 0.1% formic acid. The analytes were detected by mass spectrometer with an electrospray ionization source operating in the negative ion mode. The linearity, precision, accuracy, dilution reliability, recovery, matrix effects, and stability of the method were within acceptable ranges. The developed method was successfully used to compare the pharmacokinetic characteristics of five analytes in normal and type 2 diabetics rats after oral administration of Puerariae lobatae radix extract. Several pharmacokinetic alterations were observed and this might be caused by the pathological state of type 2 diabetes.

Comparative pharmacokinetic study on three formulations of Astragali Radix by an LC-MS/MS method for determination of formononetin in human plasma.

Astragali Radix (AR) is a widely used traditional Chinese medicine for healing the cardiovascular, liver and immune systems. Recently, superfine pulverizing technology has been applied to developing novel formulations to improve bioavailability of the active constituents in herbs, such as ultrafine granular powder of AR. In this study, a universal and sensitive quantitative method based on LC-MS/MS was employed for determining formononetin, the main flavonoid in AR, in human plasma for comparative pharmacokinetics of three oral formulations of AR. Formononetin and IS (quercetin) were extracted by ethyl acetate from human plasma and were separated on a C18 column with a mobile phase consisting of acetonitrile and 0.1% formic acid. Positive-ion electrospray-ionization mode was applied in mass spectrometric detection. The quantitative method was validated with regards to selectivity, linearity, accuracy and precision, matrix effect, extraction recovery and stability, and was applied to comparing the pharmacokinetics of ultrafine granular powder (UGP), ultrafine powder (UP) and traditional decoction pieces (TDP) of AR after oral administration. The peak concentration and areas under the concentration-time curve of formononetin in UGP and UP were significantly higher than those of TDP. UGP and UP could significantly improve the bioavailability of AR in human compared with TDP after oral administration.

Alteration of UDP-glucuronosyltransferase 1a1, 1a7 and P-glycoprotein expression in hepatic fibrosis rats and the impact on pharmacokinetics of puerarin.

BACKGROUND: Puerarin, derived from a traditional Chinese herb Pueraria lobata (Willd.) Ohwi which was distributed globally and planted in most parts of China, has been extensively applied in patients with cardiovascular diseases in China. Yet a considerable proportion of the patients were accompanied with liver illnesses simultaneously because of all sorts of reasons. HYPOTHESIS/PURPOSE: It had been implied by some previous research that the absorption and the metabolism of puerarin were susceptible to liver issues due to changed P-gp and Ugt1a level, but pharmacokinetics of puerarin under such conditions were few concerned. Our study aimed to make sure whether and how much the behavior of puerarin in vivo was affected by hepatic diseases, and to explore the potential mechanisms. METHODS: A CCl4 induced rat model of hepatic fibrosis (HF) was prepared and verified. Single low/high doses of oral and intravenous administration of puerarin to HF and normal rats were performed. Pharmacokinetics of puerarin were determined by a validated HPLC method. The expression of P-gp, Ugt1a1, and Ugt1a7 in both liver and intestines were determined by quantitative RT-PCR and Western blot analysis respectively. RESULTS: The systemic exposure of puerarin in HF rats of experimental groups were found decreased remarkably except for that of the high dose intravenous group. Moreover, the expression of P-gp, Ugt1a1, and Ugt1a7 in liver and intestines of HF rats were figured out increased. CONCLUSION: The results indicated that the HF originated overexpression of Ugt1a1, Ugt1a7, and P-gp level played important roles in pharmacokinetics of puerarin, suggested the clinical regimen of puerarin based on normal populations might be inappropriate for patients with chronic liver diseases. It was implied drugs whose absorption or elimination were related to P-gp, Ugt1a1, or Ugt1a7 might also be affected by hepatic illnesses.

Comparative pharmacokinetics of major bioactive components from Puerariae Radix-Gastrodiae Rhizome extracts and their intestinal absorption in rats.

Puerariae Radix (PR) and Gastrodiae Rhizome (GR) is frequently used in traditional herbal formulas to treat cardio-cerebral vascular diseases due to their synergistic effects. In this study, to elucidate the action mechanism of PR-GR in vivo, a simple and reliable ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for simultaneous determination of nine bioactive ingredients from PR-GR in plasma was developed and applied to a comparative pharmacokinetic study following oral administration of PR, GR, and PR-GR aqueous extracts in rats. The effect of GR on the absorption of components of PR was also investigated by single-pass intestinal perfusion study. Results showed that comparing to the single herbs, PR-GR extract significantly increased the systemic exposure of puerarin, 3'-hydroxypuerarin, 3'-methoxypuerarin, 6″-O-xylosylpuerarin, daidzin, genistein, and gastrodin. Moreover, the intestinal absorption of puerarin and daidzin could be improved by GR extract and inhibitors of P-glycoprotein and multidrug resistanceassociated protein 2, respectively. These results indicate that the combination of PR and GR increases the levels of their bioactive ingredients exposed in the blood, and GR increases the absorption of ingredients of PR may by inhibition of the efflux mediated by P-glycoprotein and multidrug resistanceassociated protein 2. This is the first report for the pharmacokinetics and intestinal absorption of PR-GR, which may explain their synergetic effects in the treatment of circulatory systematic diseases and provide a meaningful insight for their clinical applications.

A pharmacokinetic study on oleracone C after oral and intravenous administration.

Oleracone C, a new homoisoflavanone recently isolated from the plant Portulaca oleracea L., has obvious pharmacological activities. Subsequently, its pharmacokinetic profiles in rats' plasma after oral and intravenous administrations were studied by a simple and rapid ultra high-performance liquid chromatography electrospray ionization quadrupole-time of flight mass spectrometry (UHPLC-ESI-Q-TOF/MS) with apigenin as an internal standard (IS). The analysis was performed on an Agilent Zorbax Eclipse Plus C18 Column (2.1 × 50 mm, 1.8 µm) by elution with acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.3 mL/min. Electrospray ionization in negative ion mode was used to quantify oleracone C and apigenin, with monitored ion m/z values of 299.0915 [M - H]- and 269.0455 [M - H]-. The linear range was established over the concentration range 10-2000 ng/mL (r = 0.9971). The limit of detection (LOD) and limit of quantification (LOQ) were 3 and 10 ng/mL for oleracone C, respectively. The RSD and RE of intra- and inter- day accuracy and precision were all less than 15%. The pharmacokinetic results indicated that oleracone C was rapidly distributed with the time to peak concentrations of 0.03 h and 0.33 h, respectively after intravenous and oral administrations and presented a low absolute bioavailability of 8.32%. This is the first study to successfully examine the pharmacokinetics of homoisoflavanone in rats' plasma after oral and intravenous administrations, using rapid, sensitive and specific UHPLC-ESI-Q-TOF/MS method.

Quantification of isoflavone glycosides and aglycones in rat plasma by LC-MS/MS: Troubleshooting of interference from food and its application to pharmacokinetic study of Semen Sojae Praeparatum extract.

The isoflavones widely exist in the daily diets and interferences are usually inevitable in the determination of the in vivo level of the same analytes. A new strategy to eliminate the dietary interference was established to evaluate the exposure of isoflavones including daidzin, glycitin, genistin, daidzein, glycitein, and genistein in rats fed with Semen Sojae Praeparatum (SSP) extract. Plasma samples were pretreated by liquid-liquid extraction with ethyl acetate using quercetin as the internal standard (IS). The chromatographic separation was achieved on a Symmetry C18 column (100 mm × 3.0 mm) using a gradient mobile phase consisting of acetonitril and water (containing 0.1% formic acid) with a run time of 13.0 min at a flow rate of 0.4ml/min. The detection was carried out by a triple-quadrupole tandem mass spectrometer in multiple reaction monitoring (MRM) mode via polarity switching between negative (for and positive (for daidzin glycitin) ionization mode. All calibration curves exhibited good linearity (r> 0.99) over a wide concentration range for all components. The lower limit of quantitation (LLOQ) was in the range of 0.1-0.4 ng/ml. The intra-day and inter-day precisions (RSD) at three different levels were both less than 14.9% and the accuracies (RE) ranged from -9.3% to 14.5%. The extraction recoveries of the analytes and the IS ranged from 85.7% to 100.2%. The validated method was first successfully applied to pharmacokinetic study of the six isoflavones in rat plasma after oral administration of SSP extract. The dynamic baseline levels of six isoflavones in blank plasma from rats consuming food containing dietary isoflavones were measured for the correction of the plasma concentrations. The principle pharmacokinetic parameters were calculated from rats with or without regular commercial food, and found to be altered by the dietary food containing some isoflavones.

A simple and sensitive LC-MS/MS approach for simultaneous quantification of six bioactive compounds in rats following oral administration of aqueous extract and ultrafine powder of Astragalus propinquus: Application to a comparative pharmacokinetic study.

A rapid, simple and selective approach based on ultra-high performance liquid chromatography tandem with mass spectrometry was established and validated for simultaneous quantification of six compounds in rat plasma, including astragaloside I, astragaloside II, astragaloside IV, calycosin­7­O­ß­d­glucoside, ononin and formononetin. The approach was applied to a comparative pharmacokinetic investigation of routine aqueous extract and ultrafine powder of Astragalus propinquus. Six compounds were extracted from plasma by using one-step protein precipitation. Chromatographic separation was conducted with a Waters BEH C18 UHPLC column using mobile phases of acetonitrile/0.1% formic acid-water. Multiple reaction monitoring (MRM) was optimized for mass quantification in a triple quadrupole mass spectrometer. The approach elicited good linearity for the six compounds (r2 > 0.9991) in the concentration ranges. The lower limits of quantification (LLOQ) of astragaloside IV, astragaloside II, astragaloside I, calycosin­7­O­ß­d­glucoside, ononin and formononetin were determined as 6.0, 9.6, 11.8, 5.8, 6.9, and 9.4 ng/mL, respectively. Intra- and inter-day precision, accuracy, selectivity and stability of the method met the required limits. The extraction recoveries of the six compounds were from 91.1% to 107.5% and the matrix effects ranged from 92.1% to 106.7%. The normalized Cmax and AUC0-t values of calycosin­7­O­ß­d­glucoside, and formononetin of the ultrafine powder group was much higher than that of the routine aqueous extract. Administration of Astragalus propinquus in the form of ultrafine powder showed enhanced bioavailability than that of routine aqueous extract.

Effects of isoflavones on breast tissue and the thyroid hormone system in humans: a comprehensive safety evaluation.

Isoflavones are secondary plant constituents of certain foods and feeds such as soy, linseeds, and red clover. Furthermore, isoflavone-containing preparations are marketed as food supplements and so-called dietary food for special medical purposes to alleviate health complaints of peri- and postmenopausal women. Based on the bioactivity of isoflavones, especially their hormonal properties, there is an ongoing discussion regarding their potential adverse effects on human health. This review evaluates and summarises the evidence from interventional and observational studies addressing potential unintended effects of isoflavones on the female breast in healthy women as well as in breast cancer patients and on the thyroid hormone system. In addition, evidence from animal and in vitro studies considered relevant in this context was taken into account along with their strengths and limitations. Key factors influencing the biological effects of isoflavones, e.g., bioavailability, plasma and tissue concentrations, metabolism, temporality (pre- vs. postmenopausal women), and duration of isoflavone exposure, were also addressed. Final conclusions on the safety of isoflavones are guided by the aim of precautionary consumer protection.

[Intestinal absorption of puerarin nanocrystalline self-stabilizing pickering emulsion in rats].

To study the intestinal absorption characteristics of drug's nanocrystalline self-stabilizing Pickering emulsion (NSSPE) in situ in rats. Rat single-pass intestinal perfusion model was established, and high performance liquid chromatography (HPLC) was used to detect the concentration of puerarin in rat intestinal perfusion solution, assay the absorption rate constant (Ka) and the intestinal apparent permeability coefficient (Papp) of NSSPE in duodenum, jejunum, ileum, and colon, which were compared with those of raw material, nanocrystal and normal emulsion, respectively. For NSSPE, the Ka and Papp values were in the following order: duodenum>jejunum>ileum (P<0.05)>colon (P<0.01). However, there was no obvious difference between jejunum and ileum. As compared with raw material, nanocrystal and normal emulsion, the Ka and Papp values of NSSPE in duodenum were significantly higher than those of other three preparations (P<0.05); and the Ka and Papp values of NSSPE in jejunum and colon were significantly higher than those of raw material, nanocrystal and normal emulsion (P<0.01); and the Ka and Papp of NSSPE in ileum were also higher than those of raw material and normal emulsion (P<0.05), but had no obvious difference with nanocrystal. The results showed that NSSPE could significantly improve the absorption of puerarin in the intestine of rats.