Chemical composition and toxicity of waste dump leachates using Selenastrum capricornutum Printz (Chlorococcales,Chlorophyta)

Chemical composition and toxicity of leachates from a municipal waste dump in Buenos Aires Province were analyzed. Three sets of samples, obtained in 1996 and 1997, were compared. Levels of nitrogen, phosphorus, and organics (expressed as COD) were distinctly lower in 1997. Such differences were mainly attributed to higher rainfall in that year. The Selenastrum capricornutum assay showed a high sensitivity to heavy metals (Cd=0.049 mg L⁻¹; Cr hexavalent=0.247 mg L⁻¹ and Zn=0.037 mg L⁻¹). Cu, Zn, and Pb concentrations were toxic to algae in leachate samples of the first year, while the EC₅₀ leachates were slightly toxic (86.6 and 99.31%). Most likely, high levels of organics (COD=4640 and 3470 mg L⁻¹) form complex mixtures with metals reducing their toxicity. The EC₅₀ leachate=48.5% in the last year may be explained by high concentrations of Pb and Cu. © 2000 John Wiley & Sons, Inc. Environ Toxicol 15: 76–80, 2000     

The toxicity of brass dust to the microalgae Ankistrodesmus falcatus and Selenastrum capricornutum

The toxicity of brass dust was examined by conducting 96 h growth inhibition tests. Two species of algae were used, Ankistrodesmus falcatus (EC50 = 0.316 mg brass/l) and Selenastrum capricornutum (EC50 = 0.056 mg brass/l). Brass dissociates into two components, Cu (68.5%) and Zn (27.5%). Enhanced algal growth was exhibited at concentrations of 0.01 and 0.001 mg brass/l. Available literature on the toxicity of copper to S. capricornutum (EC50 = 0.047 mg Cu/l), indicate that the toxicity of brass dust is due to the ionized copper. Reported toxicities of zinc are orders of magnitude lower than copper. The ionization of the brass is dependent on pH and hardness. The literature cites cases in which copper toxicity varies with pH, clay content and dissolved organics. At present little is known of the fate and distribution of brass dust upon the release into the environment. However, the presence of heavy metals has consistently been shown to impact aquatic systems.     

Ozone toxicity: Effect of dietary vitamin E and polyunsaturated fatty acids

The roles of vitamin E and dietary polyunsaturated fatty acids (PUFA) in the acute toxicity of ozone have been investigated. After equilibration on test diets, the lung lipids of male CD-1 mice had an altered peroxidizability index (PI) which was effected by the content of dietary PUFA but not by vitamin E acetate. Mice fed 0 or 10.5 vitamin E acetate had the same mortality (LT50 of 29–32 days) on exposure to 1 ppm ozone, regardless of the significant differences in lung PI between groups fed high or low PUFA diets. High supplemental levels (105.0 ) of vitamin E acetate were protective and delayed the LT50 to 1 ppm ozone by an average of 15 days. The mode of action of vitamin E and the interaction with high levels of PUFA and ozone appear complex.     

Preliminary toxicity tests using the green alga,Ankistrodesmus falcatus

The freshwater green alga Ankistrodesmus falcatus was cultured in increasing concentrations of Cr, Hg, Cd, Zn, and Al to evaluate the effect of these cations on its growth. Algal growth was estimated by absorbance at 750 nm. Potassium dichromate was used as reference for test reproducibility. The EC₅₀ for 3 tests was 1.890 mg L⁻¹ with a coefficient of variation of 40.25%. The 96 h static EC₅₀'s for heavy metals (in mg L⁻¹ of nominal concentrations) were as follows: Cr⁶⁺/K₂Cr₂O₇, 1.050; Hg²⁺/Hg(SCN)₂, 0.162; Hg²⁺/HgCl₂, 0.074; Cd²⁺/CdCl₂ · H₂O, 0.292; Zn²⁺/ZnSO₄ · ZH₂O, 2.432; and Al³⁺/Al₂(SO⁴)₀ · 18H₂O, 0.904. Thus yielding a toxicity series such that Hg > Cd > Al > Cr > Zn. These preliminary results suggest that bioassays using A. falcatus could be suitable for evaluating the toxicity of heavy metals in freshwaters. © 1997 by John Wiley & Sons, Inc. Environ Toxicol Water Qual 12: 11–14, 1997     

Marine fatty acids aggravate hepatotoxicity of α-HBCD in juvenile female BALB/c mice

Oily fish, a source of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFAs), may contain persistent organic pollutants (POPs), including α-hexabromocyclododecane (α-HBCD). In experimental studies, marine LC n-3 PUFAs ameliorate fatty liver development while HBCD exposure was found to cause liver fatty acid (FA) changes. The present study investigated interactions of FAs and α-HBCD in juvenile female BALB/c mice using a factorial design. Mice (n = 48) were exposed for 28 days to a low (100 μg*kg body weight (BW)⁻¹*day⁻¹) or high dose (100 mg*kg BW⁻¹*day⁻¹) of α-HBCD in diets with or without LC n-3 PUFAs. High dose α-HBCD affected whole body lipid metabolism leading to changes in body weight and composition, and pathological changes in hepatic histology, which surprisingly were aggravated by dietary LC n-3 PUFAs. Hepatic FA profiling and gene expression analysis indicated that the dietary modulation of the hepatotoxic response to the high dose of α-HBCD was associated with differential effects on FA β-oxidation. Our results suggest that in a juvenile mouse model, marine FAs accentuate hepatotoxic effects of high dose α-HBCD. This highlights that the background diet is a critical variable in the risk assessment of POPs and warrants further investigation of dietary mediated toxicity of food contaminants.     

Acute and subchronic mammalian toxicity of naphthenic acids from oil sands tailings.

Naphthenic acids are the most significant environmental contaminants resulting from petroleum extraction from oil sands deposits. In this study, a mixture of naphthenic acids isolated from Athabasca oil sands (AOS) tailings pond water was used in acute and subchronic toxicity tests with rodents, in order to assess potential risks posed to terrestrial wildlife. Dosages were chosen to bracket worst-case environmental exposure scenarios. In acute tests, adult female Wistar rats were given single po dosages of naphthenic acids at either 3, 30, or 300 mg per kg body weight (mg/kg), while adult male rats received 300 mg/kg. Food consumption was temporarily suppressed in the high-dose groups of both sexes. Following euthanasia 14 days later, histopathology revealed a significant incidence of pericholangitis in the high-dose group of both sexes, suggesting hepatotoxicity as an acute effect. Other histological lesions included brain hemorrhage in high-dose males, and cardiac periarteriolar necrosis and fibrosis in female rats. In subchronic tests, naphthenic acids were po administered to female Wistar rats at 0.6, 6, or 60 mg/kg, 5 days per week for 90 days. Results again suggested the liver as a potential target organ. The relative liver weight in the high-dose group was 35% higher than in controls. Biochemical analysis revealed elevated blood amylase (30% above controls) and hypocholesterolemia (43% below controls) in high-dose rats. Excessive hepatic glycogen accumulation was observed in 42% of animals in this group. These results indicate that, under worst-case exposure conditions, acute toxicity is unlikely in wild mammals exposed to naphthenic acids in AOS tailings pond water, but repeated exposure may have adverse health effects.     

Reduced toxicity of diuron to the freshwater green alga Pseudokirchneriella subcapitata in the presence of black carbon

Black carbon (BC) is known to act as supersorbent for many organic contaminants. Its presence in surface waters at a level of a few mg/L, which may occur, e.g., after storm events in urban areas, might result in a reduced bioavailability of many contaminants and thus greatly impact their potential toxicity. Photosynthesis-inhibiting phenyl urea derivatives, such as diuron, are widely used as herbicides and diuron is regularly measured in European freshwater systems. In this study, the toxicity of diuron to the freshwater green alga Pseudokirchneriella subcapitata was investigated in the presence of BC in its native and combusted form. As a toxicity endpoint, the in vivo chlorophyll fluorescence was determined and used to indicate the bioavailability of diuron. Fifty milligrams native BC/L reduced effects of 5mugdiuron/L on photosynthesis by 10+/-2%, whereas photosynthesis was completely restored in the presence of the same concentration of combusted BC, suggesting a significantly enhanced adsorption of diuron to the BC fraction compared to the organic carbon fraction. Assuming an environmentally realistic concentration of approximately 1.5mg of combusted BC/L, diuron toxicity would be reduced by approximately 20% in surface waters due to the presence of BC. Higher BC concentrations after storm events might reduce the toxicity even further. A calculation of the Freundlich sorption coefficient K(F,BC,tox) via the toxicity endpoint, resulted in a log K(F,BC,tox) of the combusted BC of 5.7, which is comparable to values obtained by classical sorption experiments. This study contributes to a refined risk assessment of micropollutants in surface waters taking into account the presence of potentially relevant sorbents and, consequently, reduced bioavailability.     

红毛菜的氨基酸和脂肪酸分析

分析了红毛菜中氨基酸和脂肪酸的组成与含量，结果表明，红毛菜氨基酸含量为40．27％，必需氨基酸含量为20．30％，且组成十分均衡，游离氨基酸含量为4992．68ug.g^-1干品，其中大部分是呈味氨基酸和牛磺酸，不饱和脂肪酸占总脂肪酸的83．98％，EPA占51．739％，因此红毛菜是一种味道鲜美，营养丰富的天然保健食品。     

Omega-3 fatty acids and hypertension in humans

1. Population studies and clinical trials provide compelling evidence that omega-3 (omega3) fatty acids have cardioprotective effects. The strongest evidence is from DART and GISSI-P, two secondary prevention trials in patients with previous myocardial infarctions. Data from these trials support a reduction in ventricular fibrillation as a primary mechanism for the decreased incidence of myocardial infarction. 2. Evidence suggests that w3 fatty acids may also provide protection against stroke, particularly ischaemic stroke. 3. The cardioprotective effects of omega3 fatty acids relate to improvements in blood pressure, cardiac function, arterial compliance and vascular function, as well as improved lipid metabolism, antiplatelet and anti-inflammatory effects. 4. Clinical trials in humans have shown that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have different haemodynamic properties. Docosahexaenoic acid may be more favourable in lowering blood pressure and heart rate, as well as improving vascular function. However, the effects of EPA and DHA may also differ depending on the target population.     

高效液相色谱法测定人和小鼠粪便中短链脂肪酸

目的建立高效液相色谱测定人和小鼠粪便中短链脂肪酸的方法。方法样品进行衍生化处理,采用高效液相色谱法测定乙酸、丙酸、丁酸以及戊酸。YMC-Pack FA型色谱柱(250 mm×6.0 mm,5μm),流动相甲醇–水(60∶40,0.1%三氟乙酸调节p H值至4.5),检测波长400 nm,体积流量1.0 m L/min,柱温50℃,进样量20μL。结果乙酸、丙酸、丁酸、戊酸分别在0.300~6.005 mg/L(r=0.999 2)、0.370~7.408 mg/L(r=0.998 5)、0.441~8.811 mg/L(r=0.997 3)、0.511~10.210 mg/L(r=0.997 9)线性关系良好;平均加样回收率分别为93.27%、96.40%、95.67%、95.43%,RSD值分别为4.62%、5.42%、3.64%、3.92%。结论方法操作简单,精密度、稳定性、重复性良好,可用于测定人、小鼠粪便中短链脂肪酸。     

Acute toxicity to freshwater organisms of antiparasitic drugs for veterinary use

The acute toxicity of five antiparasitic drugs used in the veterinary field-amprolium hydrochloride (APH), bithionol (BT), levamisole hydrochloride (LVH), pyrimethamine (PYM) and trichlorfon (TRC)-to the aquatic organisms Oryzias latipes, Daphnia magna, and Brachionus calyciflorus was examined. The toxicity test with O. latipes was conducted in accordance with the OECD Guidelines for the Testing of Chemicals (1993) to determine the 24-, 48-, 72-, and 96-h LC(50) values. In addition, 24- and 48-h EC(50) values for D. magna and a 24-h EC(50) for B. calyciflorus were determined with the DAPHTOXKIT F(trade mark) magna (Creasel, Belgium) and the ROTOXKIT F(trade mark) (Creasel, Belgium), respectively. High-performance liquid chromatographic analysis revealed that APH, LVH, and PYM were stable in water, but BT was unstable, decreasing by 84% on average at 24 h. TRC rapidly decomposed, with only 0.7% of the initial concentration remaining after 96 h, forming dichlorvos. The toxicity of TRC to O. latipes was determined in two ways: exposure to the same medicated water for 96 h (static test) and exposure to medicated water replaced every 24 h (semistatic test). AMP, LVM, and PYM were tested in the static condition, and BT was tested in the semistatic condition. BT was most toxic to O. latipes, with a 96-h LC(50) of 0.24 mg L(-1), followed by PYM, with a 96-h LC(50) of 5.6 mg L(-1). The 24-, 48-, 72-, and 96-h LC(50) values of TRC in the static test were 92.0, 45.2, 29.5, and 17.6 mg L(-1), respectively, which tended to be lower than those in the semistatic test, especially late in the observation period. D. magna was the most susceptible to TRC, with a 48-h EC(50) as low as 0.00026 mg L(-1). The 48-h EC(50) values of BT, PYM, and LVH for D. magna were 0.3, 5.2, and 64.0 mg L(-1), respectively. B. calyciflorus was the most susceptible to BT, with an EC(50) of 0.063 mg L(-1), followed by PYM, with an EC(50) of 15.0 mg L(-1). Among the test compounds, APH was the least toxic to all the freshwater organisms tested, with a 96-h LC(50) of >600 mg L(-1) for O. latipes, a 48-h EC(50) of 227 mg L(-1) for D. magna, and an EC(50) of 403 mg L(-1) for B. calyciflorus.     

非诺贝特和辛伐他汀对酒精性脂肪肝血清游离脂肪酸谱的影响

目的　研究非诺贝特和辛伐他汀对酒精性脂肪肝大鼠模型血清游离脂肪酸谱的影响。方法　以酒精灌胃加橄榄油饮食的方法建立酒精性脂肪肝大鼠模型 ,模型组分为非诺贝特治疗组 (80mg·kg-1)、辛伐他汀治疗组 (4mg·kg-1)以及未治疗组。 4wk后处死大鼠 ,用气相色谱方法测定血清游离脂肪酸谱。结果　非诺贝特治疗组明显改善由乙醇引起的血清多不饱和脂肪酸的降低 [油酸 :(38 2 12± 7 788) μg·L-1vs (31 6 2 0± 6 14 2 ) μg·L-1,亚油酸 :(37 2 6 9± 8 0 6 5 ) μg·L-1vs (30 2 5 4± 9 0 6 3) μg·L-1,花生四烯酸 :(11 6 4 6±2 6 0 1) μg·L-1vs (9 0 12± 1 2 36 ) μg·L-1) ;同时肝脏病理改善。辛伐他汀治疗组则加重血清多不饱和脂肪酸的降低 ,并使饱和脂肪酸增加。结论　非诺贝特和辛伐他汀对酒精性脂肪肝血清游离脂肪酸谱作用不同 ;血清多不饱和脂肪酸在酒精性脂肪肝的发病机制以及治疗反应中可能起着重要的作用     

饱和脂肪酸与心血管疾病关系的研究进展

摘要： 关于饱和脂肪酸 （SFA） 对心血管疾病的作用现在观点不一, 食物种类来源、 SFA碳链的奇偶和链长是很大的影响因素。本文回顾了饱和脂肪酸对心血管疾病危险因素的影响, 除了中链饱和脂肪酸 （MCSFA）, 其余类型的 SFA可使血压升高, SFA对血管功能中度有害, 随着摄入时间的延长, 乳制品导致血脂异常的风险将增大, 纯棕榈油和椰子油对降低血脂有帮助, 摄入SFA碳链的奇偶和长度不同的SFA, 罹患2型糖尿病的风险不同; 同时总结了SFA 对心血管疾病 （CVD） 患病风险的影响, 总体SFA的摄入会增加CVD的风险, 但不同食物有不同的影响, 富含SFA的椰子油会导致心肌纤维化, 乳制品尤其是奶酪的摄入可降低CVD的发病风险, 红肉对心血管健康中度有害。     

Acute toxicity and bioaccumulation of arsenic in freshwater clam Corbicula fluminea

Arsenic is a potent human carcinogen of skin, lung, and urinary bladder. Freshwater clam Corbicula fluminea is a commercially important native species in Taiwan. C. fluminea is also a suitable biomonitoring test organism. Little is known, however, about the actual effects of arsenic on C. fluminea. The objectives of this study were to provide information on the acute toxicity and bioaccumulation kinetics of arsenic in C. fluminea. We carried out a 14-day exposure experiment to obtain bioaccumulation parameters. Uptake was very rapid when C. fluminea was first exposed and then slightly decayed during the uptake phase of the experiment and an uptake rate constant of 1.718 +/- 6.70 (mean +/- SE) mL g(-1) d(-1) was estimated. The elimination of arsenic from C. fluminea obeyed first-order depuration kinetics (r(2) = 0.85, p < 0.05) with a calculated half-life of 6.80 days. The derived bioaccumulation factor of 16.84 suggests that arsenic has a high potential for bioaccumulation in C. fluminea. This had important implications for dietary exposure of arsenic to humans who eat contaminated clams, because the soft tissue usually constitutes the majority of tissue consumed. The 96-h LC50 value was estimated to be 20.74 (95% CI: 11.74-30.79) mg L(-1) obtained from a 7-day acute toxicity bioassay. We also kinetically linked an acute toxicity model and a Hill sigmoid model to reconstruct an internal effect concentration based dose-response profile to assess the effect of soft tissue arsenic burden on the C. fluminea mortality. This result could be used to support the establishment of an ecological risk assessment to prevent possible ecosystem and human health consequences.     

Exposure of fatty acids after a single oral administration of sacha inchi (Plukenetia volubilis L.) and sunflower oil in human adult subjects

Context: Sacha inchi (Plukenetia volubilis L.) is a potential oilseed crop because it is rich in α-linolenic acid (ALA) (omega-3 fatty acid).

Objective: To evaluate the exposure of fatty acids after a single oral administration of sacha inchi or sunflower oil in healthy volunteers.

Material and methods: Plasma fatty acids concentrations were assayed by Gas Chromatography with Flame Ionization Detector in 18 adult subjects. After fasting, blood samples were obtained at 0, 0.5, 1, 2, 4, 8 and 24?h after ingestion of 10 or 15?ml of sacha inchi oil or sunflower oil.

Results: The proportion ALA/linoleic acid was 1.37 in sacha inchi oil and 0.01 in sunflower oil. ALA, lauric acid, palmitic acid, linolelaidic acid, cis-8,11,14-eicosatrienoic acid, cis-13,16-docosadienoic acid and cis-4,7,10,13,16,19-docosahexaenoic acid (DHA) levels changed over time after sacha inchi oil ingestion but not with sunflower oil. The time at maximal concentration (t_max) for ALA was 2?h after sacha inchi oil ingestion. No ALA in plasma was observed after sunflower oil consumption. The maximal concentration of ALA was 2.84?±?0.36?mg/ml in women and 0.94?±?0.57?mg/ml in men, p?p?>?0.05). There is a trend for higher plasma ALA levels with 15?ml sacha inchi oil. After 2?h of consumption, plasma delta triacylglycerol were reduced with sunflower oil but slightly increased with sacha inchi oil. A reduction in plasma delta triacylglycerol-rich lipoprotein cholesterol was observed with both oils.

Conclusion: Consumption of sacha inchi oil increased ALA and DHA in plasma.     

猫爪草中脂肪酸成分的GC—MS分析

目的:采用 GC-MS 法对猫爪草中的脂肪酸进行分析。方法:使用 RTX-5MS(30 m×0.25 mm,0.25 μm)弹性石英毛细管色谱柱,采用程序升温,进样口温度为280℃,分流比为20:1,流速为1.1 mL·min~(-1),分析时间共20 min,对猫爪草提取物的甲酯化样品进行 GC-MS 分析,质谱图用 NIST 谱库检索,鉴定各种脂肪酸,并用色谱峰面积归一化方法测定其相对含量。结果:鉴定出18种脂肪酸,主要成分亚油酸、软脂酸、油酸、亚麻酸和硬脂酸的相对百分含量分别为48.11%,21.37%,13.75%,8.86%,1.75%。结论:本法简便、快速,灵敏度高。