Antioxidant Responses Versus DNA Damage and Lipid Peroxidation in Golden Grey Mullet Liver: A Field Study at Ria de Aveiro (Portugal)

The present work aimed to investigate golden grey mullet (Liza aurata) liver protection versus damage responses at a polluted coastal lagoon, Ria de Aveiro (Portugal), as a tool to evaluate the human impacts on environmental health at five critical sites in Ria de Aveiro (Portugal) in comparison to a reference site (Torreira; TOR). Protection was evaluated by measuring non-enzymatic [total glutathione (GSHt) and non-protein thiols (NPT)] and enzymatic [catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione reductase (GR)] antioxidant defenses. Damage was assessed as DNA integrity loss and lipid peroxidation (LPO). No significant differences were found between sites in terms of non-enzymatic defenses (GSHt and NPT). CAT did not display significant differences among sites. However, GPx at Barra (BAR, associated with naval traffic), Gafanha (GAF, harbor and dry-dock activities area), Laranjo (LAR, metal contaminated associated with chlor–alkali plant), and Vagos (VAG, contaminated by polycyclic aromatic hydrocarbons) was significantly lower than the reference site. GST was lower at GAF, Rio Novo do Príncipe (RIO, pulp mill effluent area), LAR, and VAG, whereas GR was lower at RIO. The loss of antioxidant defenses was paralleled by higher LPO levels only at GAF and VAG. However, no DNA integrity loss was found. Results highlight the importance of the adopted multibiomarkers as applied in the liver of L. aurata in coastal water pollution monitoring. The integration of liver antioxidant defense and damage responses can improve the aquatic contamination assessment.     

Chemical Composition and Biological Activity of the Centipeda minima (Asteraceae)

The antimicrobial activity of the Centipeda minima L. (Asteraceae) extract was evaluated against seven microorganisms using the disc diffusion method. The extract showed a broad spectrum of antimicrobial activity against all the tested bacterial strains, especially Enterobacter aerogenes, Klebsiella pneumonia, Staphylococcus aureus and Yersinia enterocolitica. The chemical composition of the extract obtained from Centipeda minima was analysed by GC-MS. Twentythree compounds, constituting about 84.75 % of the total extract, were identified. The main constituents were palmitic acid (7.47%), (Z,Z)-9-,12-octadecatrienoic acid (6.52%), (Z,Z,Z)-9-,12-octadecatrienoic acid (7.01%), phytol (7.01%), naptho[2.3-b]furan-2-(3H)-on (6.21%), 1-(1,2,3,4,7,7a-hexahydro-1,4,4,5-tetramethyl-1,3a-ethano-3aH-inden-6-yl)etanon (7.95%), 1,3,5-tri-tertbutyl- benzene (4.52%), (3Z)-2-methyl-3-octen-2-ol (5.95%) and artemisia ketone (4.98%). The extract was also tested against brine shrimp for toxicity. There was no significant toxicity as it only recorded a LC50 value of 4.92 mg/ml. The study shows that the extract is a good antimicrobial agent with potential applications in public health against diseases.     

Aliphatic hydrocarbons in birds of prey from Galicia (NW Spain)

Eleven aliphatic hydrocarbons, unresolved over resolved ratio (U/R), carbon preference index (CPI), pristane/C17 ratio, and totals were determined in six classes of tissues (heart, liver, intestine, muscle, lung, and kidney) of 10 buzzards (Buteo buteo), 10 barn owls (Tyto alba), and five tawny owls (Strix aluco) from Galicia (NW Spain). Among individuals detected at quantifiable levels, in general, C18 was found to be the most abundant. Total aliphatic hydrocarbons were detected in 77% tissue samples. Phytane was detected in only three samples: intestine and muscle of two buzzards and lung of one barn owl. Pristane was found in 15% of total samples. Juveniles had higher concentrations than adults in the three species. Females had higher levels than males except for C32 and C36 in barn owl, C24 in tawny owls, and all hydrocarbons (except pristane) in buzzards. The highest concentrations of aliphatic hydrocarbons were detected in birds from La Coru?a     

Biological and Chemical Characterization of Metal Bioavailability in Sediments from Lake Roosevelt,Columbia River,Washington, USA

We studied the bioavailability and toxicity of copper, zinc, arsenic, cadmium, and lead in sediments from Lake Roosevelt (LR), a reservoir on the Columbia River in Washington, USA that receives inputs of metals from an upstream smelter facility. We characterized chronic sediment toxicity, metal bioaccumulation, and metal concentrations in sediment and pore water from eight study sites: one site upstream in the Columbia River, six sites in the reservoir, and a reference site in an uncontaminated tributary. Total recoverable metal concentrations in LR sediments generally decreased from upstream to downstream in the study area, but sediments from two sites in the reservoir had metal concentrations much lower than adjacent reservoir sites and similar to the reference site, apparently due to erosion of uncontaminated bank soils. Concentrations of acid-volatile sulfide in LR sediments were too low to provide strong controls on metal bioavailability, and selective sediment extractions indicated that metals in most LR sediments were primarily associated with iron and manganese oxides. Oligochaetes (Lumbriculus variegatus) accumulated greatest concentrations of copper from the river sediment, and greatest concentrations of arsenic, cadmium, and lead from reservoir sediments. Chronic toxic effects on amphipods (Hyalella azteca; reduced survival) and midge larvae (Chironomus dilutus; reduced growth) in whole-sediment exposures were generally consistent with predictions of metal toxicity based on empirical and equilibrium partitioning-based sediment quality guidelines. Elevated metal concentrations in pore waters of some LR sediments suggested that metals released from iron and manganese oxides under anoxic conditions contributed to metal bioaccumulation and toxicity. Results of both chemical and biological assays indicate that metals in sediments from both riverine and reservoir habitats of Lake Roosevelt are available to benthic invertebrates. These findings will be used as part of an ongoing ecological risk assessment to determine remedial actions for contaminated sediments in Lake Roosevelt.     

Estrogenicity of alkylphenols and alkylated non-phenolics in a rainbow trout (Oncorhynchus mykiss) primary hepatocyte culture

Alkylphenols act as estrogen mimics by binding to and transactivating estrogen receptors (ERs) in fish. In the present study, activation of ER-mediated production of the estrogenic biomarker vitellogenin (vtg) in a primary culture of rainbow trout (Oncorhynchus mykiss) hepatocytes was used to construct a structure-activity relationship for this ubiquitous group of aquatic pollutants. The role of alkyl chain length and branching, substituent position, number of alkylated groups, and the requirement of a phenolic ring structure was assessed. The results showed that most alkylphenols were estrogenic, although with 3-300 thousand times lower affinity than the endogenous estrogen 17beta-estradiol. Mono-substituted tertiary alkylphenols with moderate (C4-C5) and long alkyl chain length (C8-C9) in the para position exhibited the highest estrogenic potency. Substitution with multiple alkyl groups, presence of substituents in the ortho- and meta-position and lack of a hydroxyl group on the benzene ring reduced the estrogenic activity, although several estrogenic alkylated non-phenolics were identified. Co-exposures with the natural estrogen 17beta-estradiol led to identification of additional estrogenic compounds as well as some anti-estrogens. A combination of low affinity for the ER and cytotoxicity was identified as factors rendering some of the alkylphenols non-estrogenic in the bioassay when tested alone.     

Population Structure and Dynamics of Gammarus fossarum (Amphipoda) Upstream and Downstream from Effluents of Sewage Treatment Plants

Two streams in Germany (Körsch and Lockwitzbach), each with two sampling sites above and below a sewage treatment plant (STP) discharging effluent, were investigated. Sampling sites were characterized, and exposure monitoring for chemicals with known or assumed endocrine disrupting potential was carried out. Both the population structure and the population dynamics of Gammarus fossarum were examined. The physicochemical parameters measured at the sampling sites of the Lockwitzbach and Körsch streams were found not to reach levels having an acute toxic impact on the development of gammarids. The calculated estrogenic potential in the stream water was 22- to 35-fold higher at the downstream site of the Körsch compared with the other sampling sites, mainly because of the concentrations of 17α-ethinylestradiol on two sampling dates. At both streams, an influence of the respective STP effluent on the sex ratio of G. fossarum was not observed. Moreover, intersexuality was not induced by these effluents. Differences in the structure and dynamics of G. fossarum populations were more pronounced at the Körsch than at the Lockwitzbach. At the downstream sampling site at the Körsch, gammarids reached their highest abundances. Particularly at the downstream sampling site of the Körsch, the proportion of breeding female gammarids and the proportion of juvenile gammarids in the smallest body length class were decreased compared with upstream. Adult gammarids were larger from the Lockwitzbach downstream site, but they were smaller from the Körsch downstream site compared with the respective upstream site. At the Körsch, the earlier onset of the autumnal reproductive resting period could be caused by the influence of the STP effluent.     

Heavy metal (Cd, Pb, Zn) and metalloid (As) content in raptor species from Galicia (NW Spain)

As top consumers in food chains, birds of prey forage over large geographical areas and so might be expected to accumulate environmental contaminants which are distributed in the environment. These wild animals can offer opportunities to detect and assess the toxicological effects of different inorganic elements on terrestrial ecosystems. In this study, different raptor species, both diurnal and nocturnal, were investigated for heavy metal (Pb, Cd and Zn) and As concentrations in liver samples, with the aim of furnishing indirect information concerning contamination of their habitats. Dead animals were obtained with the special collaboration of the Wildlife Rehabilitation Centres from Galicia (NW Spain). After sample wet digestion, metal analysis was performed by inductively coupled plasma-mass spectrometry (ICP-MS). Hepatic concentrations of Zn and As, respectively, situated on the interval 147-298 and 1.21-6.88 ppm (dry weight, dw), could be considered as indicative of low and background amounts of both elements, with no ecotoxicological concern. Nevertheless, with respect to Pb, some diurnal raptors showed hepatic concentrations above the considered threshold value (6 ppm dw) for sublethal or lethal toxicity, the species with the highest hepatic level corresponding to a common buzzard (>18 ppm, dw). Similarly, nocturnal raptors exceeded the threshold value for Cd (3 ppm dw), with a maximum corresponding to an individual barn owl (39 ppm, dw). In both cases, although concentrations could not be directly related to lethal effect, they might constitute a serious environmental factor affecting the survival of the considered populations.     

Genotyping Characterization of Toxoplasma gondii in Cattle,Sheep, Goats and Swine from the North of Portugal

Background: Epidemiological investigations on Toxoplasma gondii infection have found a significant association between human toxoplasmosis and consumption of raw or undercooked meat. The present study aimed to characterize genotypes of T. gondii in 20 cattle, 40 sheep, 15 goats and 16 pigs from the North of Portugal.Methods: Nested PCR amplified the surface antigen 2 (SAG2) gene. Sequencing analysis was performed in order to assess the prevalence of SAG2 type strains (I, II and III). Results: Three and 4 strains of SAG2 type II were identified in heart samples of cattle and sheep, respectively. Three SAG2 type II strains were detected in brain, diaphragm and heart of 3 pigs. Three strains detected in heart samples of 3 goats belonged to SAG2 types I or II; with the same result being observed in heart samples from 2 sheep and in 2 brain and 1 heart samples from 3 pigs. Conclusion: SAG2 type II has been shown for the first time to infect cattle in North of Portugal. In addition, SAG2 type II has also been confirmed as the predominant strain in sheep and pigs in the same region. This is the first molecular report of T. gondii in goats from Portugal.Key Words: Genotypes, Portugal, Ruminants, Swine, Toxoplasma gondii     

Use of Japanese Medaka (Oryzias latipes) and Tilapia (Oreochromis mossambicus) in Toxicity Tests on Different Industrial Effluents in Taiwan

In Taiwan, aquatic toxicity tests for industrial effluents are not required for discharge permits. However, relying on traditional chemical and physical characteristics of an effluent to monitor and regulate such discharges to manage water quality of a receiving water is insufficient. In this study, we used two fish species, Japanese medaka (Oryzias latipes) and tilapia (Oreochromis mossambicus), and three toxic endpoints, including acute and subacute toxicity, to determine toxicity of seven different types of industrial effluents. Prior to the study, two reference toxicants were tested on two fish species. The LC50s of CdCl₂ for tilapia and medaka juveniles were 29.6 ± 15.3 mg/L and 2.2 ± 1.2 mg/L, respectively. The sensitivity of medaka embryo mortality and hatching inhibition to CdCl₂ were about the same, with the LC50 and EC50 of 0.3 ± 0.1 mg/L and 0.1 ± 0.1 mg/L, respectively. The LC50s for tilapia and medaka juveniles to sodium dodecyl sulfate (SDS) were 19.7 ± 10.6 mg/L and 12.5 ± 5.9 mg/L. The medaka embryo was less sensitive to SDS than to CdCl₂. The embryo's LC50 for SDS was 5.8 ± 2.8 mg/L and the hatching inhibition EC50 was 1.3 ± 1.1 mg/L. Results of toxicity tests on different effluents showed that the electroplating effluent was the most toxic, followed by acrylonitrile manufacturing and pulp/paper mill discharges. The LC50s of the electroplating effluent to different assays were in the range of several percents of the whole effluent. The pulp/paper effluent was toxic only to the medaka embryo. The rest of the industrial effluents tested showed either moderate or no toxicity to the animals. Received: 12 June 2000/Accepted: 6 September 2000     

Toxicity Assessment of Two Soils from Jales Mine (Portugal) Using Plants: Growth and Biochemical Parameters

Contaminants in soils can enter food chains through primary producers. Bioavailable contaminants can induce growth, and reproductive or biochemical changes in plants. To evaluate the bioavailability of heavy metals in two soils from Jales mine surroundings, bioassays with the plants Brassica rapa (RCBr) and Avena sativa were performed. Biochemical parameters (protein and malondialdehyde [MDA] content, and catalase and peroxidase activities) were also measured. The soils had different heavy metal contents: JNC soil contained low heavy metal concentrations, whereas JC soil had high heavy metal contents. Results stressed the difference between species sensitivity, with A. sativa showing no toxicity effects when exposed to both soils. On the other hand, B. rapa presented a decrease in growth parameters when exposed to JNC soil and no changes when exposed to JC soil. A Life Cycle Bioassay confirmed this trend for B. rapa exposed to JNC soil, but also evidenced that JC soil was affecting B. rapa in terms of flower and seed pod production. Biochemical assays showed that plants affected by heavy metals also displayed oxidative stress, with an increase in MDA production, reduction of protein content, and reduction of catalase and peroxidase activities. All bioassays revealed that JNC soil, although with a lower heavy metal content, had a higher bioavailable fraction when compared to JC soil, which consequently increased its toxicity to plants.     

The Effect of Advanced Treatment of Sewage Effluents on Metal Speciation and (bio)Availability

The bioavailability of metals can be strongly influenced by dissolved organic carbon (DOC). Wastewater treatment effluents add considerable quantities of DOC and metals to receiving waters, and as effluent controls become more stringent advanced effluent treatments may be needed. We assessed the effects of two types of advanced treatment processes on metal availability in wastewater effluents. Trace metal availability was assessed using diffuse gradients in thin films and predicted through speciation modelling. The results show little difference in metal availability post-advanced treatment. EDTA-like compounds are important metal complexants in the effluents.     

黑升麻的雌激素活性及其对人类乳腺癌MCF-7细胞雌激素受体水平的影响

为了检测黑升麻 (CR)的雌激素活性及其对人类乳腺癌 MCF- 7细胞雌激素受体 (ERs)水平的影响 ,未成年雌性小鼠按体重以 75、15 0和 30 0 m g/ kg的 CR灌胃 14d,观察处于动情期的时间 ,第 15天处死后取子宫和卵巢称重。以 MTT实验筛选 CR的最佳细胞作用剂量 ,观察对照组、CR组 (4.75μg/ L )和 17β-雌二醇组 (0 .3nmol/ L)的细胞生长曲线 ,并在流式细胞仪上用间接免疫荧光法测定各组 ERs水平。结果发现子宫重量随 CR剂量增加而增加 ,30 0 mg/ kg的 CR可显著增加动情天数 (P<0 .0 5 )。 4.75 μg/ L CR对 MCF- 7细胞的促增殖作用最强 ,达 6 4.7% ;CR组和 17β-雌二醇组的细胞群体倍增时间 (TD)分别为 32 .1h和31.7h,明显低于对照组 (TD=35 .3h) ;4.75 μg/ L 的 CR可显著增加细胞的 ERs水平 (P<0 .0 1)。结果表明CR具有雌激素活性 ,其升高 ERs水平的作用可能是该物质可治疗更年期综合征的机制之一。