PK-PD Correlation of Erigeron Breviscapus Injection in the Treatment of Cerebral Ischemia-Reperfusion Injury Model Rats.

By measuring the cerebral infarction rate and neurological behavioral score of rats in a sham operation group, an MCAO model control group and an Erigeron breviscapus injection treatment group, we explored the therapeutic effects of Erigeron breviscapus injection on brain tissue and neuroethological injury in rats. Plasma samples were collected at 18 time points after intravenous injection of Erigeron breviscapus. The levels of scutellarin, 4-caffeoylquinic acid, 5-caffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, chlorogenic acid and isochlorogenic acid B in rat plasma at the various time points were determined by an HPLC method, and drug concentration versus time plots were constructed to estimate the pharmacokinetic parameters. Finally, a PK-PD combined model was used to analyze the relationship between the blood concentration, time and therapeutic effects of the seven active components. The results of the pharmacodynamics studies showed that the cerebral infarction rate of rats in the Erigeron breviscapus injection group decreased significantly at 5 min, 10 min, 20 min, 6 h, 8 h, 18 h, 24 h, 32 h, 40 h and 48 h after cerebral ischemia. Abnormal neurological behavior scores were significantly reduced after 4 h of cerebral ischemia. The pharmacokinetics results showed that the seven chemical constituents in Erigeron breviscapus injection reached their highest detection value after 5 min of cerebral ischemia. The lowest detection values of scutellarin and isochlorogenic acid B appeared after 6 h of cerebral ischemia but could not be detected after 8 h. The lowest detection values of 5-caffeoylquinic acid and 4,5-dicaffeoylquinic acid were found in the third hour of cerebral ischemia but not after 4 h. The lowest detection values of 4-caffeoylquinic acid, 3,5-dicaffeoylquinic acid and chlorogenic acid were found during the second hour of cerebral ischemia but not at the third hour. However, at 18 h, 24 h, 32 h and 40 h of cerebral ischemia, the cerebral infarction rates of rats in the Erigeron breviscapus injection group were significantly reduced, with decreased values of 6.22%, 11.71%, 6.92% and 4.96%, respectively, and the effects were stronger than those after 5-20 min of cerebral ischemia. The decreased values reached their highest value after 24 h of cerebral ischemia. Our results show that the effects of Erigeron breviscapus injection on reducing the cerebral infarct rate in MCAO model rats are characterized by a fast onset and long maintenance time. The 5-min blood concentration in cerebral ischemia was the highest test value, and after this time, the cerebral infarction rate of MCAO rats began to decrease. However, the peak value of the effects lagged behind that of the plasma concentration. The maximum effective time for Erigeron breviscapus injection appeared 24 h after cerebral ischemia, which provides a reference for the screening of specific drugs for ischemic stroke, optimal dosing regimens and rational clinical drug use. Graphical Abstract.

ß-Glucuronidase- and OATP2B1-mediated drug interaction of scutellarin in Dengzhan Xixin Injection: A formulation aspect.

Scutellarin is the major and active constituent of Dengzhan Xixin Injection (DZXX), a traditional Chinese medicine prepared from the aqueous extract of Erigeron breviscapus and widely used for the treatment of various cerebrovascular diseases in clinic. In present study, the possible pharmacokinetic differences of scutellarin after intravenous administration of scutellarin alone or DZXX were explored. Additional, the potential roles of ß-glucuronidase (GLU) and OATP2B1 in drug-drug interaction (DDI) between scutellarin and constituents of DZXX were further evaluated in vitro. The plasma concentration, urinary and biliary excretion of scutellarin in rats after administration of DZXX, were significantly higher than those received scutellarin, while pharmacokinetic profile of Apigenin 7-O-glucuronide (AG) in rats was similar no matter AG or DZXX group. Furthermore, higher concentration in brain and plasma, however, lower level of scutellarin in intestine were observed after intravenous administration of DZXX. Finally, AG and caffeoylquinic acid esters were found to significantly inhibit GLU and OATP2B1 in vitro, which might explain, at least in part, the pharmacokinetic DDI between scutellarin and other chemical constituents in DZXX. The findings provided deep insight into the prescription-formulating principle in DZXX for treating the cerebrovascular diseases.

Identification and characterization of chemical constituents in Dengzhan Shengmai Capsule and their metabolites in rat plasma by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Dengzhan Shengmai Capsule (DZSMC) is a traditional Chinese medicine (TCM) formula with remarkable clinical effect in the treatment of stroke sequelae. Exploring the components of DZSMC and detecting the absorbed prototype constituents and metabolites in blood are of great significance to clarify the effective substances of this prescription. Here, a reliable method using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) was established for the comprehensive analysis of chemical constituents of DZSMC and their metabolites in rat plasma after gastric perfusion. Two acquisition modes, including MSE mode and Fast DDA mode, were performed for acquiring more precursor ions and cleaner precursor-product ions background during the study of constituents of DZSMC. As a result, a total of 125 constituents were unambiguously characterized or tentatively identified. For the first time, a total of 92 components, including 44 prototype components and 48 metabolites were unambiguously or tentatively identified in rat plasma. The metabolic pathways included phase I reactions (hydration, hydrogenation, oxidation, demethylation and hydroxylation) and phase II reactions (conjugation with glucuronide, sulfate and methyl). Furthermore, the metabolites from caffeic acid and scutellarin were characterized and validated by phase II metabolic reactions in vitro, which could be established as a simulated in vivo environment of metabolites identification and verification of TCM formula. It is the first systematic study on metabolism of DZSMC in vivo and could also provide a valid analytical strategy for characterization of the chemical compounds and metabolites of TCM formula.

A Novel Ileocolonic Release Peppermint Oil Capsule for Treatment of Irritable Bowel Syndrome: A Phase I Study in Healthy Volunteers.

INTRODUCTION: Peppermint oil (PO) has been shown to reduce abdominal pain in patients with irritable bowel syndrome (IBS). PO is assumed to induce intestinal smooth muscle relaxation and desensitization of nociceptive nerve afferents. To increase colonic PO concentration, an ileocolonic release peppermint oil (IC-PO) capsule has been developed. The aim of this study was to compare pharmacokinetic parameters of the currently available small intestinal release PO (SI-PO) and the novel IC-PO. METHODS: In this randomized, double-blind, crossover study, subjects received 182 mg of either SI-PO or IC-PO in a crossover design with a washout period of more than 14 days. Blood samples were collected to determine menthol glucuronide concentrations. RESULTS: Eight healthy volunteers (50% female, median age 22) were included. The time to reach the maximum concentration (Tmax) of IC-PO was significantly longer compared to SI-PO with a median (IQR) of 360 (360-405) versus 180 (120-180) min. The lag time (Tlag) was significantly longer with a median (IQR) of 225 (204-284) for IC-PO compared to 37 (6-65) min for SI-PO. The areas under the menthol glucuronide plasma concentration-time curves were significantly smaller with a median (IQR) of 2331 µg h/L (2006-2510) for IC-PO compared to 2623 µg h/L (2471-2920) for SI-PO. No significant differences were found in peak concentrations and elimination half-lives. CONCLUSION: IC-PO has a significantly delayed peak menthol glucuronide concentration and Tlag, both pointing to the release of PO in the more distal part of the intestine. This may enhance therapeutic efficacy as it results in increased exposure of colonic mucosal afferents to the PO. A randomized controlled trial investigating the efficacy of SI and IC-PO in IBS is currently ongoing. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02291445, EudraCT database 2014-004195-32.

Comparative pharmacokinetic study of baicalin and its metabolites after oral administration of baicalin and Chaiqin Qingning capsule in normal and febrile rats.

An accurate, precise, selective, and sensitive high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) method was developed for the simultaneous determination of baicalin and its metabolite, baicalein 6-O-glucopyranuronoside, in normal and febrile rats plasma. Two analytes, along with hesperidin as an internal standard, were determined by multiple reactions monitoring (MRM) operated in the positive electrospray ionization (ESI) mode. Chromatographic separation was performed on an Agilent ZORBAX Extend-C18 column (100mm×2.10mm, 3.5µm) with a mobile phase of 0.1% formic acid solution and acetonitrile at a flow rate of 0.6mL/min. The calibration curves showed good linearity (r≥0.9974) with the concentration ranges of 2.000-2000ngmL-1 for baicalin and baicalein 6-O-glucopyranuronoside. The inter- and intra-day accuracies (relative error, RE%) were between -6.62% and 6.75%, and the precisions (relative standard deviation, RSD%) were less than 9.09% for quality control samples (QCs). The method also possessed good selectivity, recovery and stability, and was successfully applied to a comparative pharmacokinetic study of baicalin and baicalein 6-O-glucopyranuronoside in normal and febrile rats after oral administration of baicalin and Chaiqin Qingning capsule.

Alcohol Consumption-Related Metabolites in Relation to Colorectal Cancer and Adenoma: Two Case-Control Studies Using Serum Biomarkers.

Alcohol is a known carcinogen that may be associated with colorectal cancer. However, most epidemiologic studies assess alcoholic beverage consumption using self-reported data, leading to potential exposure misclassification. Biomarkers of alcohol consumption may provide an alternative, complementary approach that reduces misclassification and incorporates individual differences in alcohol metabolism. Therefore, we evaluated the relationship between previously identified alcohol consumption-related metabolites and colorectal cancer and adenoma using serum metabolomics data from two studies. Data on colorectal cancer were obtained from a nested case-control study of 502 US adults (252 cases, 250 controls) within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Data on colorectal adenoma were obtained from a case-control study of 197 US adults (120 cases, 77 controls) from the Navy Colon Adenoma Study. Unconditional multivariable logistic regression models were fit to calculate odds ratios (OR) and 95% confidence intervals (CI) for eight alcohol consumption-related metabolites identified in a previous analysis: ethyl glucuronide; 4-androstene-3beta,17beta-diol disulfate 1; 5-alpha-androstan-3beta,17beta-diol disulfate; 16-hydroxypalmitate; bilirubin (E,Z or Z,E); cyclo (-leu-pro); dihomo-linoleate (20:2n6); and palmitoleate (16:1n7). We found no clear association between these alcohol consumption-related metabolites and either endpoint. However, we did observe an inverse association between cyclo (-leu-pro) and colorectal adenoma that was only observed in the highest metabolite quantile (OR 4th vs. 1st Quantile = 0.30, 95% CI: 0.12-0.78; P-trend = 0.047), but no association for colorectal cancer. In conclusion, there were no adverse associations between alcohol consumption-related metabolites and colorectal cancer or adenoma.

Clinical tolerability and pharmacokinetics of Erigerontis hydroxybenzene injection: results of a randomized phase I study in healthy Chinese volunteers.

Multiple phenolic compounds in the extract of Erigeron breviscapus synergistically contribute to the neurovascular protective effects. We conducted a phase I and pharmacokinetic study with the phenolic compound-enriched product extracted from Erigeron breviscapus, Erigerontis hydroxybenzenes injection (EHI), in healthy Chinese volunteers. A randomized, open-label, single-center, double-arm, dose-escalation study of EHI was conducted. The tolerability of intravenously EHI administrated in single- or multiple-dose (once daily for 7 days) was studied in 40 healthy Chinese volunteers and the pharmacokinetics of EHI was studied in additional 10 volunteers. The tolerated dose of intravenous infusion of EHI in healthy Chinese volunteers was 6 vials (equivalent to 90 mg bioactive phenolic compounds). The main limitations to dose escalation of EHI were transit changes in electrocardiogram and mild, transit increase in alanine aminotransferase. After intravenous administration of EHI, the average systemic clearance of multiple phenolic compounds of scutellarin, 1,3-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, and 3,4-dicaffeoylquinic acid were 131, 29, 262, 112 L/h for male volunteers and 202, 28, 252, 117 L/h for female volunteers. The intervention of intravenous infusion of EHI in healthy Chinese volunteers was generally tolerated. The findings from this study provide data on the tolerability and pharmacokinetics of the extract from Erigeron breviscapus and support further trials.

Simultaneous determination of scutellarin and tetrahydropalmatine of Deng-yan granule in rat plasma by UFLC-MS/MS and its application to a pharmacokinetic study.

Deng-yan granule, consisting of Herba Erigerontis Breviscapi, Rhizoma Corydalis Yanhusuo and Radix Astragali Mongolici, is a widely used Traditional Chinese Medicine preparation for treatment of coronary heart disease. Scutellarin and tetrahydropalmatine are main active constituents in Herba Erigerontis Breviscapi and Rhizoma Corydalis Yanhusuo, and have been used as marker components for quality control of Deng-yan preparations. In order to make good and rational use of Deng-yan granule in the future, a rapid, sensitive and high throughput ultra-fast liquid chromatography with tandem mass spectrometry (UFLC-MS/MS) method was developed for the simultaneous determination of scutellarin and tetrahydropalmatine in rat plasma using rutin as internal standard (IS). The plasma samples were extracted by liquid-liquid extraction with ethyl acetate after acidification and separated on a Shim-pack XR-ODS C18 column (75mm×3.0mm, 2.2µm) with a mobile phase consisting of methanol-0.1% formic acid water (50:50, v/v) at a flow rate of 0.4mL/min. Mass spectrometric detection was conducted on an API 3200 QTRAP mass spectrometry equipped with electrospray ionization source in positive ionization mode. Quantification was performed using multiple reaction monitoring (MRM) by monitoring the fragmentation of m/z 463.2→287.1 for scutellarin, m/z 356.1→192.1 for tetrahydropalmatine and m/z 611.2→303.2 for IS, respectively. The linear range was 10-5000ng/mL for both scutellarin and tetrahydropalmatine with lower limit of quantitation (LLOQ) of 10ng/mL. The intra- and inter-day precisions were below 12.2% for scutellarin and below 9.7% for tetrahydropalmatine in terms of relative standard deviation (RSD), and the accuracy was within ±9.1% for scutellarin and within ±11.2% for tetrahydropalmatine in terms of relative error (RE). Extraction recovery, matrix effect and stability were satisfactory in rat plasma. The validated method was successfully applied to a pharmacokinetic study of scutellarin and tetrahydropalmatine after oral administration of Deng-yan granule to rats.

Pharmacokinetic interaction between scutellarin and valsartan in rats.

Scutellarin is the main effective constituent of breviscapine, a flavonoid mixture isolated from the dried whole plant of Erigeron breviscapus (Vant.) Hand-Mazz, and valsartan is used as an antihypertensive drug. These two drugs have already been clinically used together to treat diabetic nephropathy (DN) in China, and the combined medications showed some enhanced protection against DN. The aim of this study is to investigate the potential pharmacokinetic interaction between scutellarin and valsartan in rats. Breviscapine injection (20 mg x kg(-1), i.v.) and valsartan (15 mg x kg-, i.g.), either alone or together were given to 18 male Sprague-Dawley rats. Concentrations of scutellarin and valsartan were quantified by HPLC, and pharmacokinetic parameters were calculated by non-compartmental methods. We found that the pharmacokinetic parameters of scutellarin altered significantly after co-administration of oral valsartan. The plasma clearance (CL(p)) and the bile clearance (CL(b)) of scutellarin were reduced significantly in the presence of valsartan. After oral administration of valsartan with or without intravenous scutellarin, however, the pharmacokinetic parameters of valsartan were comparable. In conclusion, our data suggests that the concurrent use of valsartan reduces the biliary excretion of scutellarin, and this may be due to the inhibitory effect of valsartan on the biliary excretion of scutellarin mediated by Mrp2 (Multidrug resistance-associated protein 2).

Mechanistic studies on the absorption and disposition of scutellarin in humans: selective OATP2B1-mediated hepatic uptake is a likely key determinant for its unique pharmacokinetic characteristics.

Scutellarin [scutellarein-7-O-glucuronide (S-7-G)] displayed a unique pharmacokinetic profile in humans after oral administration: the original compound was hardly detected, whereas its isomeric metabolite isoscutellarin [scutellarein-6-O-glucuronide (S-6-G)] had a markedly high exposure. Previous rat study revealed that S-7-G and S-6-G in the blood mainly originated from their aglycone in enterocytes, and that the S-7-G/S-6-G ratio declined dramatically because of a higher hepatic elimination of S-7-G. In the present study, metabolite profiling in human excreta demonstrated that the major metabolic pathway for S-6-G and S-7-G was through further glucuronidation. To further understand the cause for the exposure difference between S-7-G and S-6-G in humans, studies were conducted to uncover mechanisms underlying their formation and elimination. In vitro metabolism study suggested that S-7-G was formed more easily but metabolized more slowly in human intestinal and hepatic microsomes. Efflux transporter study showed that S-6-G and S-7-G were good substrates of breast cancer resistance protein and multidrug resistance-associated protein (MRP) 2 and possible substrates of MRP3; however, there was no preference great enough to alter the S-7-G/S-6-G ratio in the blood. Among the major hepatic anion uptake transporters, organic anion-transporting polypeptide (OATP) 2B1 played a predominant role in the hepatic uptake of S-6-G and S-7-G and showed greater preference for S-7-G with higher affinity than S-6-G (K(m) values were 1.77 and 43.9 µM, respectively). Considering the low intrinsic permeability of S-6-G and S-7-G and the role of OATP2B1 in the hepatic clearance of such compounds, the selective hepatic uptake of S-7-G mediated by OATP2B1 is likely a key determinant for the much lower systemic exposure of S-7-G than S-6-G in humans.

[Simultaneous determination of isoorientin, scutellarin and cynaroside in rat plasma and pharmacokinetics by UPLC-MS/MS].

OBJECTIVE: To establish a UPLC-MS/MS analysical method for simultaneous determination of concentrations of isoorientin, scutellarin and cynaroside in rat plasma and to study their pharmacokinetic characteristics after intravenous injection of 3 doses of Fufang Hongcao in rats. METHOD: Acidified plasma samples were precipitated for protein with methanol. Waters Acquity BEH C18 column was adopted for spectrum, with mobile phase as 0. 1% formic acid acetonitrile-0. 1% formic acid-water gradient elution. Detection was carried out by the multiple reaction monitoring (MRM) positive ion mode with ESI ionization source. RESULT: Three flavonoids show a good linear relationship, with the extraction recovery ranging between 78.56% and 101.91% and a high intra-and inter-day precisions and accuracy. The MRT of the three flavonoids were all lower than 22 min in rats. CONCLUSION: The above men tioned method is so specific, rapid, sensitive that it is suitable for pharmacokinetic studies of Fufang Hongcao injection in rats.

[Intestinal lymphatic transport of breviscapine orally administered in rat].

Double cannulation model of conscious rat allowing simultaneous collection of mesenteric lymph and jugular venous blood was established to investigate the intestinal lymphatic transport of breviscapine orally administered in rat. The concentrations of breviscapine in plasma and lymph were determined by HPLC. The pharmacokinetics of breviscapine after oral and intravenous administration was evaluated in the conscious rat model. It was observed that scutellarin distributed from blood circulation to lymphatic system after intravenous injection. The cumulative lymphatic transport amount within 12 h was (2.78 +/- 0.25) microg, equivalent to 0.0792% of intravenous dose. After oral administration of scutellarin to double-cannulation rats, the cumulative lymphatic transport amount within 12 h was (0.92 +/- 0.08) microg, equal to 0.0083% of oral dose. The absolute bioavailability of breviscapine orally administered to double-cannulation rats was 4.91%, indicating that scutellarin was mainly absorbed into the bloodstream through the portal vein. Lymphatic transport of scutellarin appears to reflect high affinity for the lymph lipoproteins to chylomicron. This study provided a biopharmaceutics basis for developing oral lipid delivery system for the promotion of intestinal lymphatic transport to improve oral bioavailability of breviscapine.

Metabolite profiling of hydroxycinnamate derivatives in plasma and urine after the ingestion of coffee by humans: identification of biomarkers of coffee consumption.

Human subjects drank coffee containing 412 mumol of chlorogenic acids, and plasma and urine were collected 0 to 24 h after ingestion and were analyzed by high-performance liquid chromatography-mass spectrometry. Within 1 h, some of the components in the coffee reached nanomole peak plasma concentrations (C(max)), whereas chlorogenic acid metabolites, including caffeic acid-3-O-sulfate and ferulic acid-4-O-sulfate and sulfates of 3- and 4-caffeoylquinic acid lactones, had higher C(max) values. The short time to reach C(max) (T(max)) indicates absorption of these compounds in the small intestine. In contrast, dihydroferulic acid, its 4-O-sulfate, and dihydrocaffeic acid-3-O-sulfate exhibited much higher C(max) values (145-385 nM) with T(max) values in excess of 4 h, indicating absorption in the large intestine and the probable involvement of catabolism by colonic bacteria. These three compounds, along with ferulic acid-4-O-sulfate and dihydroferulic acid-4-O-glucuronide, were also major components to be excreted in urine (8.4-37.1 mumol) after coffee intake. Feruloylglycine, which is not detected in plasma, was also a major urinary component (20.7 mumol excreted). Other compounds, not accumulating in plasma but excreted in smaller quantities, included the 3-O-sulfate and 3-O-glucuronide of isoferulic acid, dihydro(iso)ferulic acid-3-O-glucuronide, and dihydrocaffeic acid-3-O-glucuronide. Overall, the 119.9 mumol excretion of the chlorogenic acid metabolites corresponded to 29.1% of intake, indicating that as well as being subject to extensive metabolism, chlorogenic acids in coffee are well absorbed. Pathways for the formation of the various metabolites within the body are proposed. Urinary dihydrocaffeic acid-3-O-sulfate and feruloylglycine are potentially very sensitive biomarkers for the consumption of relatively small amounts of coffee.

[Pharmacokinetic and tissue distribution study of scutellarin in rats].

OBJECTIVE: To investigate the pharmacokinetic and distribution character of scutellarin in plasma and tissues in rats, in order to provide some references for rational drug use in the clinic. METHOD: The solution of scutellarin was administered to rats (80 mg x kg(-1)) by oral gavage. A high performance liquid chromatography method determinated the scutellarin concentration in rat plasma and tissue. The plasma samples were performed by solid phase extraction method. The other biological samples were extracted by ethyl acetate. RESULT: The range of scutellarin in plasma and tissue in rats were 10-1280 ng x mL(-1) (R2 > 0.99), 40-1280 ng x g(-1) (R2 > 0.99), respectively. The lowest detection of scutellarin were 10 ng x mL(-1) and 40 ng x g(-1), the precision were less than 8%. The main pharmacokinetic parameters of scutellarin were as follows: tmax, Cmax, AUC and MRT being (7.7 +/- 0.9) h, (288.0 +/- 75.2) microg x L(-1), (5.6 +/- 1.6) microg x mL(-1) x h(-1), (17.5 +/- 1.4) h(-1), respectively. CONCLUSION: These methods applied the study of pharmacokinetics of scutellarin. After oral the scutellarin in rats, the concentration-time course doesn't obey any compartment model. The concentration-time curve is the double peaks.

Two major urinary metabolites of scutellarin in rats.

Urinary metabolites of scutellarin, the main effective constituent of breviscapine, a cerebrovascular and cardiovascular drug consisting of total flavonoids of Erigeron breviscapus, were investigated in rats. Two major metabolites were isolated from the urine of rats following oral administration of scutellarin and identified as scutellarein 6,7-di- O-beta-D-glucuronide (M1) and scutellarein (M2), respectively, on the basis of chemical and spectroscopic evidence. M1 was reported as a metabolite of scutellarin for the first time.

[Pharmacokinetics of breviscapine liposomes following intravenous injection in Beagle dogs].

AIM: To prepare the breviscapine liposomes and study the pharmacokinetics of breviscapine liposomes in Beagle dogs. METHODS: The cross-over design (two periods) was employed. Six Beagle dogs were administrated a single intravenous dosage of 28 mg of breviscapine liposomes and reference preparation, respectively, scutellarin in plasma of 6 dogs at different sampling time was determined by RP-HPLC. The pharmacokinetic parameters were calculated by 3P97 program and compared by statistic analysis. RESULTS: The mean concentration-time curves of breviscapine liposomes and reference preparation were both fitted to two-compartment model with the main pharmacokinetic parameters as follows: T 1/2 alpha were (4.4 +/- 0.7) min and (1.8 +/- 1.3) min respectively; T 1/2 beta were (55 +/- 27) min and (28 +/- 23) min respectively; V(c) were (1 580 +/- 265) mL and (2 460 +/- 2 200) mL respectively; CL(s) were (88 +/- 10) mL x min(-1) and (324 +/- 69) mL x min(-1) respectively; and AUC(0-720) were (363 +/- 42) microg x min x mL(-1) and (102 +/- 19) microg x min x mL(-1) respectively. The T 1/2 alpha, CL(s) and AUC(0-720) of breviscapine liposomes all had significant difference from those of reference preparation, after the data were examined by a one-way analysis of variance (ANOVA). CONCLUSION: Compared with the reference preparation, breviscapine liposomes had a much more higher concentration in plasma and contained characteristic of sustained-release, which ameliorated the pharmacokinetic properties of scutellarin.

[Study on the pharmacokinetics of scutellarin in dogs].

AIM: To determine scutellarin in dog plasma and study the pharmacokinetics of scutellarin in the dog. METHODS: Scutellarin in plasma of six dogs at different sampling time was determined after single dose of 120 mg i.v. by RP-HPLC. The mean plasma concentration-time curve was protracted and pharmacokinetic parameters were calculated. RESULTS: The concentration-time curve of scutellarin can be fitted to a three-compartment model with the main pharmacokinetic parameters as follows: T1/2 gamma, T1/2 alpha and T1/2 beta were (1.1 +/- 0.8) min, (7.0 +/- 2.8) min and (52 +/- 29) min, respectively, Vc was (880 +/- 508) mL, CL was (190 +/- 54) mL.min-1, AUC0-90 and AUC0-infinity were (574 +/- 134) mg.min.L-1 and (559 +/- 132) mg.min.L-1 respectively. CONCLUSION: The concentration of scutellarin in plasma declined rapidly after single dose of 120 mg i.v. in dogs, and this suggested that the T1/2 of scutellarin should be taken into account in preparation exploitation and drug administration.

Ethyl glucuronide concentration in serum of human volunteers, teetotalers, and suspected drinking drivers.

The kinetic profile of ethanol and ethyl glucuronide (EtG) in serum was investigated in three subject groups: 1) Healthy, moderately drinking volunteers (daily intake less than 30 g ethanol) who ingested a single dose of ethanol. In this group the maximum of serum ethyl glucuronide concentration (SEtGC) and of serum ethanol concentration (SEC) did not exceed 3.7 mg/L and 1.5 g/L respectively. EtG peaked 2 to 3.5 h later than ethanol. EtG was eliminated with a terminal half-life of 2 to 3 h. EtG decreased slower than ethanol--the metabolite could still be determined in serum up to 8 h after complete ethanol elimination. 2) In serum samples of teetotalers neither ethanol nor EtG could be found. 3) In 37 of 50 serum samples of drivers suspected of driving under the influence of ethanol, SEtGC was found between the limit of detection (0.1 mg/L) and 20 mg/L. If the SEC is less than 1 g/L and the SEtGC is significantly higher than 5 mg/L, we assume alcohol misuse.

Physiological changes in dehydroepiandrosterone are not reflected by serum levels of active androgens and estrogens but of their metabolites: intracrinology.

This study analyzes in detail the serum concentration of the active androgens and estrogens, as well as a series of free and conjugated forms of their precursors and metabolites, after daily application for 2 weeks of 10 mL 20% dehydroepiandrosterone (DHEA) solution on the skin to avoid first passage through the liver. In men, DHEA administration caused 175%, 90%, 200% and 120% increases in the circulating levels of DHEA and its sulfate (DHEA-S), DHEA-fatty acid esters, and androst-5-ene-3 beta,17 beta-diol, respectively, with a return to basal values 7 days after cessation of the 14-day treatment. Serum androstenedione increased by approximately 80%, whereas serum testosterone and dihydrotestosterone (DHT) remained unchanged. In parallel with the changes in serum DHEA, the concentrations of the conjugated metabolites of DHT, namely androsterone glucuronide, androstane-3 alpha,17 beta-diol-G, and androstane-3 beta,17 beta-diol-G increased by about 75%, 50%, and 75%, respectively, whereas androsterone-sulfate increased 115%. No consistent change was observed in serum estrone (E1) or estradiol (E2) in men receiving DHEA, whereas serum E1-sulfate and E2-sulfate were slightly and inconsistently increased by about 20%, and serum cortisol and aldosterone concentrations were unaffected by DHEA administration. Almost superimposable results were obtained in women for most steroids except testosterone, which was about 50% increased during DHEA treatment. This increase corresponded to about 0.8 nM testosterone, an effect undetectable in men because they already have much higher (approximately 15 nM) basal testosterone levels. In women, the serum levels of the conjugated metabolites of DHT, namely androsterone glucuronide, androstane-3 alpha,17 beta-diol-G, androstane-3 beta,17 beta-diol-G, and androsterone-sulfate were increased by 125%, 140%, 120% and 150%, respectively. The present study demonstrates that the serum concentrations of testosterone, DHT, E1, and E2 are poor indicators of total androgenic and estrogenic activity. However, the esterified metabolites of DHT appear as reliable markers of the total androgen pool, because they directly reflect the intracrine formation of androgens in the tissues possessing the steroidogenic enzymes required to transform the inactive precursors DHEA and DHEA-S into DHT. As well demonstrated in women, who synthesize almost all their androgens from DHEA and DHEA-S, supplementation with physiological amounts of exogeneous DHEA permits the biosynthesis of androgens limited to the appropriate target tissues without leakage of significant amounts of active androgens into the circulation. This local or intracrine biosynthesis and action of androgens eliminates the inappropriate exposure of other tissues to androgens and thus minimizes the risks of undesirable masculinizing or other androgen-related side effects of DHEA.

Toxic impact of effluents from petrochemical industry.

The toxicity of effluents from a petrochemical industry center in southern Finland was tested by conducting bioassays on organisms from three different trophic levels. In fish tests, rainbow trout (Salmo gairdneri) were caged at the discharge site and simultaneously at a reference area. The only clear differences, among the measurements of 25 metabolic parameters, were observed in fish liver where activities of two detoxication enzymes were significantly increased in the exposed group. The water flea (Daphnia magna) was used both in acute (EC50) and long-term reproduction tests. No acute lethal toxicity was detected in any of the wastewater samples investigated. A combined effluent, however, caused a reduction in the reproduction rate with an EC50 of 3%. No mutagenic activity was observed with the Ames test (Salmonella typhimurium, strains TA 97, TA 98, and TA 100) in concentrated effluents, in sediment samples, or in liver samples from predator fish caught from the discharge site.