Determining toxicity of leachates from Florida municipal solid waste landfills using a battery-of-tests approach

The toxicity and physicochemical parameters of municipal solid-waste (MSW) landfill leachates from six sites in north and north-central Florida, United States, were determined. Landfill leachates are complex mixtures of organic and inorganic constituents. Leachate toxicity was assayed using the acute C. dubia (48-h) and Microtoxtrade mark (15-min) assays and the chronic S. capricornutum (96-h) assay. The landfill leachates were shown to be highly toxic to both C. dubia and S. capricornutum with an EC(50) < 10% and < 15%, respectively. However, Microtoxtrade mark was not as sensitive to the leachates. Based on these results, the assays were ranked for their sensitivities to the landfill leachates; C. dubia > S. capricornutum > Microtoxtrade mark. Chemical analyses showed high concentrations of un-ionized ammonia and salts in the landfill leachates but low concentrations of heavy metals. The toxicity of the landfill leachates varied between the sites sampled and within each of the landfill sites. A significant relationship was found between the total ammonia content of the leachates and toxicity as determined by the C. dubia and S. capricornutum assays. Although the chemical constituents in Florida MSW landfill leachates may be more dilute, the toxicity of the leachates is equivalent to that from industrial waste landfills.     

A comparison of techniques used to extract solid samples prior to acute toxicity analysis using the microtox test

To date, there has been no widely accepted or standardized procedure for preparing leachates of solid samples for acute toxicity bioassays such as Microtox. Leaching procedures reported in the literature were evaluated for use with nonspecific environmental sample submissions. Using toxic environmental samples, two experiments were conducted to compare the effect that varying selected parameters would have on the effectiveness of the leaching procedure in removing toxicants from a solid sample matrix. Parameters that were varied included the type of toxicant, aqueous solvent system used to leach the sample, ratio of solid:liquid, type of mixing action, length of extraction time, and method of removing suspended solids from the leachate. Results from these experiments demonstrated that unacceptable variations of measured toxicity of a solid sample occurs with simple modifications of the method. The most dramatic shifts in 15 min EC₅₀ values were observed between vacuum filtering (EC₅₀ mean = 55.8%) and centrifuging (EC₅₀ mean = 22.3%) samples to clarify leachates. This and other significant interactions, between sample contaminant and aqueous system, suggest that no standard procedure will give readily interpretable results for different types of contamination. Investigators should carefully consider the application of the assay (e.g., the detection of toxicants using a sensitive method, or modeling the leaching of toxicants under specific environmental conditions) before selecting a leaching procedure. © 1996 by John Wiley & Sons, Inc.     

Acute aquatic toxicity of tire and road wear particles to alga,daphnid, and fish

Previous studies have indicated that tire tread particles are toxic to aquatic species, but few studies have evaluated the toxicity of such particles using sediment, the likely reservoir of tire wear particles in the environment. In this study, the acute toxicity of tire and road wear particles (TRWP) was assessed in Pseudokirchneriella subcapita, Daphnia magna, and Pimephales promelas using a sediment elutriate (100, 500, 1000 or 10000 mg/l TRWP). Under standard test temperature conditions, no concentration response was observed and EC/LC₅₀ values were greater than 10,000 mg/l. Additional tests using D. magna were performed both with and without sediment in elutriates collected under heated conditions designed to promote the release of chemicals from the rubber matrix to understand what environmental factors may influence the toxicity of TRWP. Toxicity was only observed for elutriates generated from TRWP leached under high-temperature conditions and the lowest EC/LC₅₀ value was 5,000 mg/l. In an effort to identify potential toxic chemical constituent(s) in the heated leachates, toxicity identification evaluation (TIE) studies and chemical analysis of the leachate were conducted. The TIE coupled with chemical analysis (liquid chromatography/mass spectrometry/mass spectrometry [LC/MS/MS] and inductively coupled plasma/mass spectrometry [ICP/MS]) of the leachate identified zinc and aniline as candidate toxicants. However, based on the high EC/LC₅₀ values and the limited conditions under which toxicity was observed, TRWP should be considered a low risk to aquatic ecosystems under acute exposure scenarios.     

Bioactivity-guided isolation and identification of anti-adipogenic compounds from Sanguisorba officinalis

Context: Sanguisorba officinalis Linne (Rosaceae) is a medicinal plant used traditionally for the treatment of inflammatory and metabolic diseases in Korea, China, and Japan. In our previous study, a 50% ethanol extract inhibited fat accumulation in 3T3-L1 adipocytes.

Objective: This study investigates bioassay-guided fractionation, isolation, and identification of anti-adipogenic bioactive compounds in S. officinalis.

Materials and methods: The bioassay-guided fractionation was conducted using effective differentiation of 3T3-L1 cells into adipocytes (with 50?μg/mL test material for 8 days) to isolate the inhibitory compounds from ethyl acetate fraction of S. officinalis 50% ethanol extract. The cytotoxicity of each fraction and isolated compound was tested using MTT assay (with 25–300?μg/mL test material). Structures of the isolated active compounds were elucidated using ¹H NMR, ^13?C NMR, HSQC, HMBC, FT-IR, and MS.

Results: An active ethyl acetate fraction obtained with solvent partition of the extract inhibited lipid accumulation (44.84%) on 3T3-L1 cells without cytotoxicity (102.3%) at the concentration of 50?μg/mL. The ethyl acetate fraction was determined to be mainly composed by isorhamnetin-3-O-d-glucuronide (1) and ellagic acid (2). Pure isorhamnetin-3-O-d-glucuronide (IC₃₀ is 18.43?μM) and ellagic acid (IC₃₀ is 19.32?μM) showed lipid accumulation inhibition on 3T3-L1 cells without cytotoxicity (117.5% and 104.3%) at the concentration of 20?μM, respectively.

Discussion and conclusions: These results suggested that S. officinalis is a potential natural ingredient for the prevention of obesity, which may due to bioactive compounds such as isorhamnetin-3-O-d-glucuronide and ellagic acid.     

Comparison and evaluation of urinary biomarkers for occupational exposure to spray adhesives containing 1-bromopropane

Three metabolites of 1-bromopropane (1-BP) were measured in urine samples collected from 30 workers exposed to 1-BP at two facilities making furniture seat cushions and evaluated for use as biomarkers of exposure. The mercapturic acid metabolite, N-acetyl-S-(n-propyl)-l-cysteine (AcPrCys), 3-bromopropionic acid (3-BPA), and bromide ion levels (Br^?) were quantitated for this evaluation. The high exposure group consisted of 13 workers employed as adhesive sprayers who assembled foam cushions using 1-BP containing spray adhesives and the low exposure group consisted of 17 non-sprayers, who worked in various jobs without spraying adhesives. All workers’ urine voids were collected over the same 48 h period at work, and at home before bedtime, and upon awakening. Urinary AcPrCys and Br^? levels were elevated in the sprayers compared to that of non-sprayers. Following HPLC-MS/MS analysis of mercapturic acid metabolite levels, 50 urine samples having the highest levels of AcPrCys were analyzed for 3-BPA. No 3-BPA was detected in any of the samples. The data collected from this study demonstrate that AcPrCys and Br^? are effective biomarkers of 1-BP exposure, but 3-BPA is not.     

Use of Microtox® and Ceriodaphnia bioassays in wastewater fractionation

Collection system and nonchlorinated secondary effluent samples from a large municipal wastewater system were fractionated using a scheme that included filration, EDTA treatment, C₁₈ solid-phase extraction columns, and air stripping. Microtox required less time than Ceriodaphnia dubia bioassay for determining the toxicity of the numerous test samples generated by the fractionation procedure. Its usefulness was limited to collection system samples, however. Secondary effluent samples, which caused significant mortality of C. dubia, were nontoxic to Microtox. Diazinon was tentatively identified as one of the causative toxicants present. Its LC₅₀ to C. dubia (0.5 μg/L) is within the range of concentrations detected (0.1–0.6 μg/L), whereas the EC₅₀ of diazinon to Microtox is much higher (> 18,000 μg/L).     

Antiestrogenicity and estrogenicity in leachates from solid waste deposits

A great deal of effort has been devoted to developing new in vitro and in vivo methods to identify and classify endocrine disrupting chemicals that have been identified in environmental samples. In this study an in vitro test based on recombinant yeast strains transfected with genes for the human estrogen receptor α was adapted to examine the presence of estrogenic and antiestrogenic substances in six Swedish landfill leachates. Antiestrogenic effects were measured as inhibition of the estradiol induced response with the human estrogen receptor α, and quantified by comparison with the corresponding inhibitory effects of a known antiestrogen, hydroxytamoxifen. The estrogenicity was within the range of that determined in domestic sewage effluents, from below the limit of detection to 29 ng estradiol units L^?1. Antiestrogenicity was detected in some of the investigated landfill leachates, ranging between <38 and 3800 μg hydroxytamoxifen equivalents L^?1. There was no apparent relation between the type of waste deposited on the landfills and the antiestrogenic effect. Fractionation of a landfill leachate showed that estrogenic compounds were located in two dominant fractions. Three estrogenic compounds were found that accounted for the estrogenic activity in extracts of leachates: bisphenol A, estradiol, and ethinylestradiol. The bisphenol may have been released from decomposing plastic waste and the estrogenic steroids from earlier deposits of municipal sewage sludge and pharmaceutical waste. Fractionation of leachates from three parts of a landfill showed that the antiestrogenic activity was distributed in at least four fractions and somewhat different in different flows of leachate. This indicated a heterogeneous mixture of antiestrogenic substances. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2011.     

Evaluation of the toxic and genotoxic potential of landfill leachates using bioassays

Landfill leachates are liquid effluents with elevated concentrations of chemical compounds that can cause serious environmental pollution. In the south of the state of Santa Catarina, Brazil, a sanitary landfill was installed that employs a system of anaerobic/facultative lagoons for the treatment of its leachate. The present work examined the toxic and genotoxic potential of untreated and treated landfill leachates using bioassays. The chemical, toxic, genotoxic and mutagenic properties of the untreated leachate and the treated leachate were determined. Examination of the chemical properties showed a marked decrease in parameters after treatment, as well as in toxicity towards all the organisms tested. The results of the comet assay demonstrated that both leachates showed genotoxicity in all of the organisms tested, indicating the persistence of genotoxic substances even after treatment. A significant decrease in micronucleated cells was detected in Geophagus brasiliensis exposed to the treated leachate compared to untreated.     

Molluscicidal and antischistosomal activities of methanol extracts and isolated compounds from Eucalyptus globulus and Melaleuca styphelioides

Context: Schistosomiasis is a parasitic disease that results in severe organ damage. Snail control is the best measure to control schistosomiasis. Plant-derived molluscicides have gained increasing attention for the control of schistosomiasis because they have low toxicity towards non-target organisms. Tannins are particularly suitable for snail control because they are less toxic than saponins to non-target organisms.

Objective: To identify the most toxic components of two plants belonging to the family Myrtaceae, namely Eucalyptus globulus Labill. and Melaleuca styphelioides Sm against the different developmental stages of Schistosoma mansoni and its snail host.

Materials and methods: The 80% MeOH leaf extracts of the tested plants and their isolated compounds were screened for their molluscicidal activity (expressed as LC₅₀ and LC₉₀ after 24?h exposure) against the snail Biomphalaria alexandrina. The anti-schistosomal activity of the tested samples was determined at 20?ppm (after 1 or 2?h exposure) against the different developmental stages of S. mansoni, including the miracidia, cercariae and worms. Biochemical parameters were measured to determine the toxicity mechanisms of the treated snails. The structures of the isolated compounds were elucidated based on NMR, UV and HRESI-MS/MS data.

Results: Potent molluscicidal activity was observed for the ellagitannin dimer eucalbanin B (12), with an LC₅₀ value of 55?ppm. Treatment of the snails with the LC₂₅ of eucalbanin B (30.8?ppm) resulted in a significant decrease in the protein level by 22.7% and 25.8% in the snail tissues and hemolymph, respectively. The decreased protein content was attributed to destruction of the snail tissue and impairment in protein synthesis under stress conditions of intoxication with eucalbanin B. Alterations in the activities of the transaminases and phosphatases in the treated snails indicated destruction and intoxication of the snail tissues. A significant increase in the levels of the transaminases alanine aminotransferase (ALT) (57.8%) and aspartate aminotransferase (AST) (113.2%) in the snail hemolymph and a significant decrease in their tissue levels to 7.4 and 48.6%, respectively, were attributed to their release from the damaged tissue into the hemolymph. Alkaline phosphatase (ALP) was significantly increased by 38.5 and 181.4% in the hemolymph and tissues, respectively. Acid phosphatase (ACP) was also significantly increased by 48.4 and 21.2% in the hemolymph and tissues, respectively. The 80% MeOH extract of E. globulus together with mallophenol B (3), 2,2,8-trimethyl-6-formyl-chrom-3-ene-7-O-β-d-glucopyranoside (5) and benzyl alcohol 7-O-(3′,4′,6′-tri-O-galloyl)-β-d-glucopyranoside (10) exhibited miracidicidal activity with almost 100% toxicity at 20?ppm for the three compounds and 80% toxicity for the extract. Moreover, E. globulus extract showed cercaricidal and schistosomicidal activity with 100 and 40% mortality, respectively.

Conclusion: E. globulus is a potential source for biocidal compounds against S. mansoni and its snail host. This is the first study to test the biocidal activity of the isolated compounds.     

Contributors to estrogenic activity in wastewater from a large wastewater treatment plant in Beijing, China

Wastewater at various stages of treatment was sampled from a large wastewater treatment plant (WWTP) in Beijing, China. A fractionation method was conducted to identify the dominant contributors to estrogenic activity of those samples using silica gel column chromatography combined with a recombinant yeast bioassay for detecting estrogenic activity and gas chromatography-mass spectrometry (GC/MS) for quantifying estrogenic substances. Total estradiol equivalents (EEQ) found in the influent and effluent of the WWTP were 15.7±2.0 and 10.4±0.4ng/L, indicating the low removal efficiency of the WWTP. The endocrine disrupting chemicals (EDCs) most frequently detected in the wastewater by GC/MS included phthalate esters, PAHs and phenolic compounds, while the natural and synthetic estrogens such as estradiol (E2), estrone (E1), and ethinylestradiol (EE2) were not detected. The concentrations of nonylphenol (NP), octylphenol (OP) and bisphenol A (BPA) were 13.4, 1.4 and 89.0μg/L in the influent and 0.41, 0.11 and 0.32μg/L in the effluent, respectively. Based on the concentrations and estradiol equivalency factors (EEF) of NP, OP and BPA, 60% of the total estrogenic activity in GBD-WWTP influent could be explained by the calculated EEQ, showing that BPA, OP and NP were mainly responsible for estrogenic activity in the influent. However, their contributions to estrogenic activity in the effluent were only 3%, indicating that some unknown estrogenic components were still present in the wastewater.     

Influence of changes in amine substitution on the β-adrenoceptor stimulant activity of soterenol and related compounds in the anaesthetized cat

1. Three 3-methanesulphonamido, 4-hydroxy ring substituted phenylethanol-amines with n -isopropyl (soterenol), n -t-butyl (MJ7999–1) and n -(1-phenyl-t-butyl) (MJ9184–1) amine substituents have been compared with (—)-isoprenaline for their ability to produce β-receptor mediated reductions in serotonin-induced increases in pulmonary resistance, decreases in soleus muscle contractility, and increases in heart rate in anaesthetized cats. For each parameter, the dose of a compound required to produce 50% of its maximal response (ED₅₀) was calculated. 2. For all three parameters (—)-isoprenaline was the most potent of the compounds studied, and the rank order of potency of the methanesulphonanilides was MJ9184–1 (n -(1-phenyl-t-butyl))?MJ7999–1 (n -t-butyl)> soterenol (N-isopropyl). 3. For each individual drug, molar dose-ratios [drug: (—)-isoprenaline] were calculated. Ratios for the effects of the compounds on the soleus muscle and in the bronchi were similar. With each compound higher dose-ratios were found in the heart. The rank order for relative β₂-selectivity was soterenol (n -isopropyl)> MJ7999–1 (n -t-butyl)?MJ9184–1 (n -(1-phenyl-t-butyl)).     

注射用酒石酸长春瑞滨胶束及注射用长春瑞滨在比格犬体内的毒动学比较

目的 测定连续给予注射用酒石酸长春瑞滨胶束的毒动学参数，并与注射用酒石酸长春瑞滨进行比较。方法 选取16只比格犬随机分为4组，雌雄各半，分别连续iv给予注射用酒石酸长春瑞滨胶束低、中、高剂量（0.29、0.58、1.174 mg/kg）与注射用酒石酸长春瑞滨1.174 mg/kg，建立测定比格犬血浆中酒石酸长春瑞滨浓度的液相色谱-串联质谱（LC-MS/MS）法，测定血药浓度，采用DAS3.1.4药动学软件计算动力学参数。结果 比格犬iv给予注射用酒石酸长春瑞滨胶束低、中、高3个剂量，血药浓度、AUC_（0-t）、C_max随给药剂量的增加而增大；连续iv给药，低、中、高剂量组动物血药浓度、AUC_（0-t）、C_max在给药第1、29、71天时均变化不大，无明显蓄积倾向。而注射用长春瑞滨胶连续iv给药后随给药时间延长，动物血药浓度、AUC_（0-t）、C_max有上升趋势，AUC_（0-t）蓄积因子分别为2.08、1.80，C_max蓄积因子分别为2.58、2.32，均有蓄积倾向。结论 注射用酒石酸长春瑞滨胶束与普通注射用酒石酸长春瑞滨毒动学参数比较，无明显的蓄积倾向，可降低长期服药的毒性风险。     

Antimicrobial and antioxidant effects of phenolic constituents from Klainedoxa gabonensis

Bioassay-guided fractionation of the methanol extract of the stem bark of Klainedoxa gabonensis Pierre ex Engl. (Irvingiaceae) afforded 12 compounds, namely, ellagic acid (1), ellagic acid 3,3′-dimethylether (2), gallic acid (3), methyl gallate (4), lupeol (5), β-amyrin (7), erythrodiol (8), oleanolic acid (9), betulinic acid (6), hederagenin (10), bayogenin acid (11), and stigmasterol-3-O-β-d-glucopyranoside (12). Compounds 1-3 and 7-12 were isolated for the first time from this genus. The structures were established on the basis of 1D/2D NMR experiments and mass spectrometric data. Crude extract, fractions (A, B, C and D) and pure compounds were tested for their antimicrobial activity using paper disk agar diffusion assay. The test delivered a range of low to high activities for phenolic compounds 1-4, low or missing activities for terpenoid compounds 5-11, and impressive very high antibacterial/antifungal values for two fractions C and D probably due to synergistic effects of compounds. The broth microdilution assay revealed MICs of 15.4-115.1?μg/mL for phenolic compounds, MICs higher than 1?mg/mL for terpenoids and MICs of 4.5-30.3?μg/mL for fractions C and D. The determination of the radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay gave high antioxidant values for the methanol extract and fraction D (IC₅₀ 10.45 and 5.50?μg/mL) as well as for the phenolic compounds 1-4 (IC₅₀ 45.50-48.25?mM) compared to the standard 3-t-butyl-4-hydroxyanisole (BHA) (IC₅₀ 44.20?mM).     

Detection and metabolic investigations of a novel designer steroid: 3‐chloro‐17α‐methyl‐5α‐androstan‐17β‐ol

In 2012, seized capsules containing white powder were analyzed to show the presence of unknown steroid‐related compounds. Subsequent gas chromatography–mass spectrometry (GC‐MS) and nuclear magnetic resonance (NMR) investigations identified a mixture of 3α‐ and 3β‐ isomers of the novel compound; 3‐chloro‐17α‐methyl‐5α‐androstan‐17β‐ol. Synthesis of authentic reference materials followed by comparison of NMR, GC‐MS and gas chromatography‐tandem mass spectrometry (GC‐MS/MS) data confirmed the finding of a new ‘designer’ steroid. Furthermore, in vitro androgen bioassays showed potent activity highlighting the potential for doping using this steroid. Due to the potential toxicity of the halogenated steroid, in vitro metabolic investigations of 3α‐chloro‐17α‐methyl‐5α‐androstan‐17β‐ol using equine and human S9 liver fractions were performed. For equine, GC‐MS/MS analysis identified the diagnostic 3α‐chloro‐17α‐methyl‐5α‐androstane‐16α,17β‐diol metabolite. For human, the 17α‐methyl‐5α‐androstane‐3α,17β‐diol metabolite was found. Results from these studies were used to verify the ability of GC‐MS/MS precursor‐ion scanning techniques to support untargeted detection strategies for designer steroids in anti‐doping analyses. Copyright © 2015 John Wiley & Sons, Ltd.     

Discovery of common urinary biomarkers for hepatotoxicity induced by carbon tetrachloride, acetaminophen and methotrexate by mass spectrometry-based metabolomics

Liver toxicity represents an important healthcare issue because it causes significant morbidity and mortality and can be difficult to predict before symptoms appear owing to drug therapy or exposure to toxicants. Using metabolomic techniques, we discovered common biomarkers for the prediction of hepatotoxicity in rat urine using mass spectrometry. For this purpose, liver toxicity was induced by 5 days of oral administration of carbon tetrachloride (1 ml kg^?1 per day), acetaminophen (1000 mg kg^?1 per day) and methotrexate (50 mg kg^?1 per day). Serum levels of alkaline phosphatase aspartate aminotransferase, alanine aminotransferase and histopathology in liver tissue were then checked to demonstrate liver toxicity. Global metabolic profiling with UPLC‐TOF‐MS (ultraperformance liquid chromatography–mass spectrometry), multivariate analysis (partial least square‐discriminant analysis, hierarchical analysis) and database searching were performed to discover common biomarkers for liver toxicity induced by these three compounds. Urinary concentrations of the newly discovered biomarkers were then quantified to confirm them as biomarkers of hepatotoxicity with targeted metabolic profiling using GC (gas chromatography)–MS and CE (capillary electrophoresis)–MS. In the results, steroids, amino acids and bile acids were metabolically changed between the control and drug‐treated groups in global metabolic profiling; 11β‐hydroxyandrosterone, epiandrosterone, estrone, 11‐dehydrocorticosterone, glycine, alanine, valine, leucine, dl ‐ornithine, 3‐methylhistidine, cholic acid and lithocholic acid were selected as liver toxicity biomarkers after performing targeted metabolic profiling. In conclusion, we discovered metabolite biomarkers belonging to three different metabolic pathways to check for liver toxicity with mass spectrometry from a metabolomics study that could be used to evaluate hepatotoxicity induced by drugs or other toxic compounds. Copyright © 2011 John Wiley & Sons, Ltd.     

栀子-闹羊花配伍对大鼠血浆中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的药动学影响

目的考察栀子与闹羊花配伍对闹羊花中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ药动学的影响。方法建立LC-MS/MS测定大鼠血浆中闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的分析方法,并用此方法测定大鼠口服给予闹羊花与栀子配伍液及闹羊花单煎液后大鼠体内的闹羊花毒素Ⅱ和闹羊花毒素Ⅲ的血药浓度,计算其药动学参数并统计分析。结果闹羊花毒素Ⅱ在1～200 ng·mL^–1、闹羊花毒素Ⅲ在1～100 ng·mL^–1内线性关系良好(r>0.999),质控样本精密度均<12%,准确度RSD<20%。栀子配伍闹羊花给药和单独给药后体内闹羊花毒素Ⅱ的AUC_0–t分别为(260.44±51.67)和(213.39±59.03) h·ng·mL^–1,闹羊花毒素Ⅲ的AUC_0–t分别为(60.97±22.78)和(22.38±5.55)h·ng·mL^–1。与闹羊花单煎给药相比,栀子与闹羊花配伍给药后闹羊花毒素Ⅱ的T_1/2和MRT₍(0–t))显著升高,闹羊...     

脑心通胶囊联合阿替普酶治疗急性脑梗死的临床研究

目的 研究银杏内酯滴丸中的主要成分银杏内酯A、B在健康受试者体内的药动学特征,为制定合理的临床给药方案提供依据。方法 采用随机、开放的试验设计,10例健康受试者单次口服银杏内酯滴丸后,按预定时间点采集血样,肝素锂抗凝,离心分离血浆。采用LC-MS/MS法测定血浆样品中银杏内酯A、B的开闭环总质量浓度,以及银杏内酯A、B闭环质量浓度,并应用WinNonlin 6.3软件非房室模型计算药动学参数。结果 健康受试者单次口服银杏内酯滴丸后,银杏内酯A闭环及开闭环总量的t_max分别为（3.05±1.40）、（3.40±1.22）h,C_max分别为（84.3±32.8）、（92.2±35.0）ng/mL,C_max比值为91.4%,AUC_0～t分别为（636±183）、（753±205）ng·h/mL,AUC_0～t比值为84.5%,t_1/2分别为（13.00±10.30）、（12.90±8.49）h;银杏内酯B闭环及开闭环总量的t_max分别为（3.15±1.42）、（3.35±1.25）h,C_max分别为（74.10±31.50）、（148.00±60.10）ng/mL,C_max比值为50.1%,AUC_0～t分别为（627±202）、（1 410±431）ng·h/mL,AUC_0～t比值为44.5%,t_1/2分别为（13.20±5.83）、（13.7±5.83）h。结论 健康受试者口服银杏内酯滴丸后,银杏内酯A、B吸收速率适中,消除速率适中,在人血浆中银杏内酯A主要以闭环形式存在,而银杏内酯B以开、闭环2种形式存在、暴露量相当。     

Metabolism and pharmacokinetics in rats of ganoderiol F,a highly cytotoxic and antitumor triterpene from <Emphasis Type="Italic">Ganoderma lucidum</Emphasis>

The metabolism of ganoderiol F (GF), a cytotoxic and antitumor triterpene from Ganoderma lucidum, by intestinal bacteria and its pharmacokinetics in rats were investigated by using liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS). GF was converted to ganodermatriol by anaerobic incubation with bacterial mixtures from rats and humans. This metabolite was detected in rat feces, but not in plasma and urine, after oral administration of GF. The fate of GF after oral (p.o.) and intravenous (i.v.) administration to rats was examined in pharmacokinetics studies. Plasma samples pretreated by solid-phase extraction were quantified by HPLC/MS/MS over a GF concentration range of 1.25–100 ng/ml (S/N = 5). The intra- and interday precision (CV%) was below 8% and accuracy was within the range of 95.9–103.6% for all samples. The range of recovery ratios was 89.2–98.2%. After the administration of GF at 0.5 mg/kg i.v., the plasma concentrations of GF quickly declined and the elimination half-life values (t _1/2α and t _1/2β) were about 2.4 and 34.8 min. On the other hand, the elimination half-life values (t _1/2α) after p.o. administration of GF at doses of 20 and 50 mg/kg were 14.4 and 143.3 min for the former, and 18.6 and 114.6 min for the latter. The AUC_0–t value was 11.17 (ng/ml) h at a GF dose of 0.5 mg/kg i.v., but 49.4 and 111.6 (ng/ml) h at GF doses of 20 and 50 mg/kg p.o., respectively, indicating that the AUC_0–t value is proportional to the administered oral doses. The estimated absolute bioavailability of GF in rats was F = 0.105.     

In vitro profiling of endocrine disrupting effects of phenols

Some phenols have been suspected to modulate the endocrine systems of wildlife and humans, but less is known about their interactions with different types of nuclear receptors. In this study, the ability of 2-tert-butylphenol, 2-isopropylphenol, 4-tert-octylphenol (4-t-OP), 2,4-dichlorophenol (2,4-DCP), 3,4-dichlorophenol (3,4-DCP), pentachlorophenol (PCP), bisphenols A (BPA), tetrabromobisphenol A (TBBPA), tetrachlorobisphenol A (TCBPA) and 4-phenylphenol to activate estrogen receptor (ER), androgen receptor (AR), progesterone receptor (PR) and estrogen-related receptor (ERR) were determined using a set of recombined yeast strains. It was found that 4-t-OP, 3,4-DCP, PCP, BPA, TBBPA, TCBPA and 4-phenylphenol were ERα agonists, while 4-t-OP, PCP and 4-phenylphenol showed ERα antagonistic activities. 2-tert-Butylphenol, 4-t-OP, 2-isopropylphenol, 2,4-DCP, 3,4-DCP, BPA, TCBPA and 4-phenylphenol were antagonists for AR, whereas none of the compounds studied were found to be an AR agonist. TCBPA, TBBPA and PCP were PR antagonists, and 2-tert-butylphenol, 3,4-DCP, 4-t-OP, 4-phenylphenol and 2-isopropylphenol were weak inhibitors on expression under control of the PR. None of the phenols were PR agonists. 2-tert-Butylphenol, 4-t-OP and PCP were ERRγ inverse agonists, while 2,4-DCP, 3,4-DCP, PCP, BPA, TBBPA and TCBPA exhibited the ability to reverse the ERR inhibition induced by 4-hydroxytamoxifen. Based on the functional agonistic or antagonistic receptor-mediated effects, we further discussed the possible action mechanisms of these phenols as endocrine disrupting chemicals.