Effect of Diets Supplemented with Different Sources of Astaxanthin on the Gonad of the Sea Urchin Anthocidaris crassispina

The effect of the microalgae Haematococcus pluvialis and Chorella zofingiensis, and synthetic astaxanthin on the gonad of the sea urchin Anthocidaris crassispina was studied. The basal diet was supplemented with H. pluvialis, C. zofingiensis, or synthetic astaxanthin, at two levels of astaxanthin (approximately 400 mg/kg and 100 mg/kg), to obtain the experimental diets HP1, HP2, CZ1, CZ2, AST1, and AST2, respectively, for two months of feeding experiment. The results showed that the concentrations of astaxanthin in the gonads of the sea urchins fed these experimental diets ranged from 0.15 to 3.01 mg/kg dry gonad weight. The higher astaxanthin levels (>2.90 mg/kg) were found in the gonads of the sea urchins fed the diets HP1 (containing 380 mg/kg of astaxanthins, mostly mono- and diesters) and AST1 (containing 385 mg/kg of synthetic astaxanthin). The lowest astaxanthin level (0.15 mg/kg) was detected in the gonads of the sea urchins fed the diet CZ2 (containing 98 mg/kg of astaxanthins, mostly diesters). Furthermore, the highest canthaxanthin level (7.48 mg/kg) was found in the gonads of the sea urchins fed the diet CZ1 (containing 387 mg/kg of astaxanthins and 142 mg/kg of canthaxanthin), suggesting that astaxanthins, especially astaxanthin esters, might not be assimilated as easily as canthaxanthin by the sea urchins. Our results show that sea urchins fed diets containing astaxanthin pigments show higher incorporation of these known antioxidant constituents, with the resultant seafood products therefore being of potential higher nutritive value.     

Antioxidants in digestive tracts and gonads of green urchin (Strongylocentrotus droebachiensis)

Digestive tracts and gonads of green urchin (Strongylocentrotus droebachiensis) were evaluated for their antioxidant potential and total phenol and flavonoid contents. Antioxidant potentials of freeze-dried samples were evaluated using lipophilic and hydrophilic oxygen radical absorbance capacity (ORAC) assays. Analyzed samples showed antioxidant activity with total ORAC values of 864 and 885 μmol of TE/g d.w. for digestive tracts and gonads, respectively. Acetonitrile-rich and ethyl acetate extracts from freeze-dried samples showed ORAC values (1500-2100 μmol of TE/g) higher than crude tissues (∼870 μmol of TE/g), while water-rich extracts were less active (260-370 μmol of TE/g). Eluates 1 and 2 obtained from C₁₈ solid-phase extraction of the water-rich fraction showed ORAC values (650-1600 μmol of TE/g) up to 6 times higher than their parent extracts. Total phenol and flavonoid contents of freeze-dried samples ranged from 53 to 123 mg of GAE/100 g d.w. and 1.4-1.8 mg of RE/100 g, respectively. ORAC values from digestive tracts samples showed significant correlations with total phenols (r² = 0.76, p = 0.049, n = 12) and flavonoids (r² = 0.80, p = 0.021, n = 12), while a very weak correlation was observed for samples from gonads. This is the first study to quantify antioxidant properties of green urchin tissues, and show that edible gonads might provide valuable antioxidants to consumers while digestive tracts might be valorized as an alternative source of antioxidants in food additive ingredients.     

Metabolism of orally administered naphthalene in spawning English sole (Parophrys vetulus)

English sole (gravid females and ripe males) were force-fed [³H]naphthalene (NPH) in salmon oil and tissues were examined at 24, 48, and 168 hr. NPH was detected in all tissues and fluids examined (e.g., liver, blood, muscle, bile, testes, and ovaries) at 24 hr. There were no statistically significant differences in NPH concentrations, based on dry weight, between comparable tissues and fluids of the sexes, except for the gonads. Ovarian NPH concentrations were approximately three times higher than those in testes. The highest percentage (5%) of the total dose at 24 hr was present in the ovaries; liver and muscle contained about 1–2% of the dose. Concentrations of NPH in all tissues declined markedly from 24 to 168 hr. At 24 hr, male English sole had significantly higher hepatic NPH hydroxylase activity than did female sole. However, no significant sex differences were evident in tissue concentrations of total metabolites of NPH. In liver, blood, and testes, the metabolites at 24 hr were composed of approximately equal proportions of conjugates and nonconjugates. Nonconjugates were the predominant metabolites in the ovaries (>88% of the total). Thin-layer chromatography (TLC) of metabolites from liver, blood, ovaries, and testes revealed that the major nonconjugate metabolite was 1,2-dihydro-1,2-dihydroxynaphthalene (diol) and glucuronides were the major conjugate class present. Both TLC and high-performance liquid chromatography indicated that the glucuronide conjugate in the liver was derived from the diol. The naphthol conjugates were not detected. The ability of fish to rapidly accumulate orally administered NPH and its metabolites in the gonads may have significant implications with respect to fertilization and subsequent development of the embryo.     

Lipofuscin-Like Pigment in Gonads of Sea Urchin <Emphasis Type="Italic">Strongylocentrotus intermedius</Emphasis> as a Potential Biomarker of Marine Pollution: A Field Study

Accumulation of lipofuscin-like pigments (LLPs) has been shown to be an appropriate index of both age and stress in some aquatic invertebrates. In the present study, LLP was quantified by measuring its autofluorescence intensity (ex 450 nm/em 512 nm) in nutritive phagocytes (NPs) of sea urchins Strongylocentrotus intermedius inhabiting polluted and relatively clean areas of Japan Sea. To avoid variations in LLP content related to sea urchin reproductive condition, only developing gonads with acini occupied mostly by NPs were used for LLP quantification as well as semiquantitative histopathological analysis. LLP concentrations ranged from 0.0 to 4.57 ± 0.53% area fraction in female gonads and from 0.0 to 4.61 ± 0.35% in male gonads. The presence of specimens with extremely high LLP concentrations (>1.5%) in all examined samples, including specimens from the reference station, as well as the absence of strong correlations between LLP concentrations and several parameters related to pollution (heavy-metal concentrations in sea urchin gonads and concentrations of heavy metals, DDT, hexachlorocyclohexane, and total petroleum hydrocarbons in sediments), allow us to conclude that LLP content in sea urchin NPs can not be used as a biomarker in marine pollution monitoring.     

Broodstock diet effect on sea urchin Paracentrotus lividus (Lamarck, 1816) endotrophic larvae development: potential for their year-round use in environmental toxicology assessment

The effect of captive broodstock diet on fertilization and endotrophic larvae development of the sea urchin Paracentrotus lividus was assessed. Maize grain and five inert pelleted diets were tested, during a three-month experimental period. Maize flour, wheat flour, soybean flour, maize/wheat flour (MWF) and maize/soybean flour mixes were used as vegetal sources for inert feed. Gonad index, percent egg fertilization and larvae malformation occurrence were compared with the results obtained from wild sea urchins (W). Whole egg total amino acid composition was concomitantly analyzed as a tool to explain eventual endotrophic larvae malformations caused by lack of specific nutrients. For all treatment groups (wild and captive), percent egg fertilization values above 96% were always observed, fulfilling the requisites (70-90%) necessary to conduct environmental monitoring bioassays, according to USEPA (2002). Similar values for normal percent larval development were only obtained from P. lividus broodstock subjected to an inert feeding diet based on a maize/wheat flour mix (85.0±1.45%), in comparison to wild P. lividus (82.5±1.75%). Likewise, no statistical differences on resultant whole egg total amino acid composition were observed between P. lividus fed MWF and wild treatments. Moreover, statistical differences between MWF and all the other captive feeding treatments were found for six out of the seventeen amino acids analyzed. This study demonstrates the possibility to obtain high values for P. lividus endotrophic larvae percent normal development based on broodstock held in captivity as long as an appropriate inert diet is provided.     

The disposition of p-nitroanisole by the sea urchin,Strongylocentrotus purpuratus: II. Biotransformation and bioconcentration

Biotransformation and bioconcentration of p-nitroanisole (PNA) in sea urchins, Strongylocentrotus purpuratus, was studied using short-term exposures in static and dynamic, flowing water, studies and under steady-state conditions. The metabolic pathway was characterized by reduction of the nitro group with subsequent acetylation of the formed p-anisidine. The extent of metabolism was less than 2.5% of the excreted material, total excretion 73 ± 11%. The metabolism varied with season, corresponding to the reproductive cycle, and with length of time held in the laboratory. The PNA had a relative weight of distribution (anagolous to volume of distribution) of 1.73 ± 0.95 and the gonads acted as the storage site. The bioconcentration factor for PNA was 6.1 ± 4.7 and had a range of 1.9–25.9. The bioconcentration factor also varied with the reproductive cycle of the sea urchin. The sea urchin demonstrated a decreased excretion of PNA with an increase in metabolism which implies that long-term exposure to PNA could be potentially harmful. These studies along with the kinetics demonstrated the usefulness of our testing protocol to distinguish the differences in the disposition of PNA in the sea urchin under different physiological states.     

The uptake metabolism and biological half-life of benzo[a]pyrene in different tissues of sea bass, Dicentrarchus labrax

The disposition of polycyclic aromatic hydrocarbons in aquatic organisms is of interest from the viewpoint of both animal and human health. The kinetics of uptake and metabolism of benzo[a]pyrene (BaP) were studied in various tissues of the marine fish, sea bass, upon intraperitoneal injection of the compound. A decrease in radioactivity occurred in all tissues and the calculated half-lives were 12.4 days for fat, 6.5 for kidney, 5.1 for intestine, 4.8 for gallbladder, 4.5 for spleen, 2.9 for muscle, 2.4 for whole body, 2.3 for gonads, 2.3 for gills, and 2.2 for liver. The kinetics of distribution of radioactivity between alkali and hexane tissue extracts were determined in order to assess the overall metabolic potential of various organs. The liver, intestine, gills, and kidney displayed a relatively high metabolic potential in comparison with the spleen, muscle, gonads, and fat. The significance of the observations with respect to understanding mechanisms of toxicity is briefly discussed. Attention is specifically drawn to the presence of a fairly active metabolism or metabolite redistribution system in the muscle and the potential for exposure of blood cells to metabolites via hydrocarbon transformation processes in the spleen. This in vivo study, in which hydrocarbon disposition was studied in various tissues, also supports the hypothesis that polycyclic aromatic hydrocarbons should not bioaccumulate to any significant degree in fish and that exposure of humans to such compounds through the consumption of fish products can be expected to be minimal.     

Impact of tributyltin and triphenyltin on ivory shell (Babylonia japonica) populations

We histopathologically examined gonads and chemically determined organotin compounds in tissues of the ivory shell, Babylonia japonica. Imposex (a superimposition of male-type genital organs on females) occurred in approximately 80-90% of B. japonica specimens that we examined, with the penis and vas deferens both well developed. No oviduct blockage by vas deferens formation was observed. Ovarian spermatogenesis and suppressed ovarian maturation were observed in the females that exhibited imposex, although no histopathological abnormalities were found in males. Tissue distributions of organotin compounds [tributyltin (TBT), triphenyltin (TPhT), and their metabolites] were different for butyltins and phenyltins; a remarkably high accumulation of TBT was observed in the ctenidium, osphradium, and heart, whereas high concentrations of TPhT were detected in the ovary and digestive gland. More than one-third of TBT accumulated in the digestive glands of both males and females, followed by the testis, ctenidium, muscle, and heart tissues in males and in the muscle, ovary, ctenidium, and head tissues (including the central nervous system ganglia) in females. In both males and females, more than half of total TPhT accumulated in the digestive glands, followed by the gonads. The next highest values were in the muscle, ctenidium, and heart tissues in males and in the muscle, oviduct, and head tissues in females. Both TBT and TPhT concentrations in the gonads were positively correlated with penis length in females. Our findings strongly suggest that reproductive failure in adult females accompanied by imposex, possibly induced by TBT and TPhT from antifouling paints, may have caused the marked decline of B. japonica populations in Japan.     

Accumulation and metabolism of carbon-14 labeled benzene,naphthalene, and anthracene by young coho salmon (Oncorhynchus kisutch)

Carbon-14 labeled benzene, naphthalene, and anthracene were administered to young coho salmon (Oncorhynchus kisutch) in the food and by intraperitoneal injection. Regardless of the mode of application the accumulated carbon-14 (% administered dose) in key organs (e.g., liver and brain) increased in the order anthracene > naphthalene > benzene over various time periods. The metabolic fate of the hydrocarbons after intraperitoneal injection was studied. It was shown that the highest percentages of metabolites occurred in the gall bladder; however, significant amounts were also found in the liver, brain, flesh, and carcass. Solvent partition and thin-layer chromatographic techniques were developed to determine the structure of individual metabolites. In brain, liver, and gall bladder, 1-naphthol and 1-naphthyl glucuronic acid were major products of naphthalene metabolism; however, glycoside/sulfate fractions and mercapturic acid were indicated. The heart and flesh were rich in 1-naphthol and the former organ contained significant amounts of 1,2-dihydro-1,2-dihydroxynaphthalene. The findings indicated that the aromatic hydrocarbons in key organs increased in relation to the number of benzenoid rings. Further, it appears that aromatic metabolites are broadly distributed throughout fish exposed to polynuclear aromatic hydrocarbons.     

Influence of time and mode of exposure on biotransformation of naphthalene by Juvenile starry flounder (Platichthys stellatus) and rock sole (Lepidopsetta bilineata)

Juvenile starry flounder (Platichthys stellatus) and rock sole (Lepidopsetta bilineata) were force-fed 56 Ci each of 1-³H-naphthalene dissolved in salmon oil. Values for radioactivity associated with naphthalene and the metabolite fraction were determined for various tissues and body fluids. Results show that these pleuronectids extensively metabolize dietary naphthalene. The rates of decline in naphthalene concentrations (expressed as disintegrations per minute per milligram of dry tissue) were greater than the rates of decline in metabolite concentrations (dpm/mg) in liver, blood, and skin; therefore, relative proportion of metabolites to naphthalene increased with time and at 168 hr after the initiation of the naphthalene-exposure, more than half of the total radioactivity in both species of fish was associated with the metabolites.Profiles of metabolites in liver, skin, and bile were obtained using thin-layer chromatography. 1,2-Dihydro-1,2-dihydroxynaphthalene constituted 38.7 and 39.7%, respectively, of the total extracted metabolites in livers of the naphthalene-exposed rock sole and starry flounder at 24 hr, whereas the bile from both species contained primarily (>90%) conjugates. From 24 to 168 hr, a significant (P < 0.05) decrease in the proportion of the dihydrodiol derivative and a concomitant increase in the proportion of conjugates—specifically, sulfate/glucoside fraction-were observed with livers of both rock sole and starry flounder. No significant change occurred in the spectrum of biliary metabolites with time. The pattern of metabolites in skin of both species was qualitatively similar to that in liver; however, the proportion of the dihydrodiol was greater in skin than in liver at 24 hr.When naphthalene (56Ci) dissolved in salmon oil was administered to starry flounder via intraperitoneal injection, the extent of biotransformation was less than after dietary exposure. Moreover, metabolites in the livers of the fish in the injection study were predominantly (76.7% of total extracted metabolites) non-conjugates at 24 hr. Once again, from 24 to 168 hr, an increase in the proportion of the sulfate/glucoside fraction and a concomitant decrease in the proportion of the dihydrodiol was observed with liver.These studies demonstrate that the extent of biotransformation of naphthalene and the types of metabolites remaining in tissues (e.g., liver) of flatfish are greatly influenced by both the mode of exposure and the time elapsed after the exposure is initiated. It appears therefore, that different exposures (e.g., in water, food, or sediment) of pleuronectids to polycyclic aromatic hydrocarbons may result in different degrees of alteration in genetic material because of variability in accumulation of non-conjugated metabolites, some of which are implicated in covalent binding with DNA in terrestrial mammals.     

Effect of environmental temperature on naphthalene metabolism by Juvenile Starry flounder (Platichthys stellatus)

Juvenile starry flounder (Platichthys stellatus) maintained at 4° or 12°C were forced-fed³H-1-naphthalene. At 24 hr, after the initiation of exposure, significantly (p < 0.05) higher concentrations (2 to 15 times) of naphthalene were present in tissues of starry flounder at 4°C than those present in fish held at 12°C. The influence of lowering of water temperature on naphthalene retention was even more marked after one week. At this time, muscle and liver of fish at 4°C contained 26 and 34 times, respectively, more naphthalene than did muscle and liver of fish at 12°C. Concentrations of total metabolites, in most tissues were not substantially higher at the lower temperature either 24 or 168 hr after the naphthalene-exposure.Thin-layer Chromatographic separation of the metabolites revealed that at 24 hr, 1,2-dihydro-1,2-dihydroxynaphthalene (dihydrodiol) was the major component in liver (40 to 50% of extracted metabolites) and muscle (-80% of extracted metabolites) regardless of the temperature. Bile contained, primarily, conjugates (e.g., glucuronides), which yielded the dihydrodiol as the principal metabolite on enzymatic hydrolysis. From 24 to 168 hr, the concentrations of each metabolite class did not vary directly with the concentrations of total metabolites. Accordingly, at 168 hr, the ratio of total metabolite concentrations in liver of fish at 4°C compared to 12°C was 1.6, whereas the ratios for the dihydrodiol, sulfate/glucoside conjugates and glucuronide conjugates were 4.5, 0.6 and 3.8 respectively.Generally, lowered water temperature increased tissue concentrations of the parent hydrocarbon and its metabolites. However, the magnitude of the increase was dependent upon the compound, the tissue, and the time after the initiation of the exposure. The results emphasize the importance of determining concentrations of individual metabolites together with parent hydrocarbons in tissues of fish when assessing effects of environmental parameters on xenobiotic toxicity.     

Biomarkers of PAHs exposure in crabs Ucides cordatus: Laboratory assay and field study

Pyrene metabolites in urine and micronucleus in haemocytes of crabs (Ucides cordatus) were tested as biomarkers of exposure to oil derived PAHs in mangrove sediments. The goal was to verify how well pyrene metabolites in urine represent levels of oil contamination in mangroves and whether the micronuclei assay indicates exposure. For this, bioassays were performed using crabs from clean and contaminated areas, and field studies were conducted in four mangroves. Results of the bioassay show that U. cordatus assimilates, metabolises, and excretes pyrene in urine as pyrene-1-glucoside, pyrene-sulphate and pyrene-conjugate. OH-pyrene-sulphate was the major metabolite produced/excreted over 120 h of observation by crabs from the clean mangrove. The production/excretion of pyrene-1-glucoside in this case increased linearly with time at a rate of 2.3×10⁻¹⁰ mol L⁻¹ day⁻¹. The number of micronuclei in haemocytes also increased with the time after pyrene inoculation, indicating that exposure to pyrene triggers genotoxic and mutagenic response. In crabs from a heavily oil-contaminated mangrove pyrene-1-glucoside was the major metabolite, an indication that production/excretion of a certain metabolite varies depending on adaptation of the animal to the environment. A highly significant correlation was found between the concentration of pyrene metabolites in urine of field crabs expressed as OH-pyrene equivalents and the sum of 38 PAHs determined in hepatopancreas/sediments (r=0.825, n=23, p<0.05). The response of these crabs to the micronuclei assay was not significantly related to concentration of individual or total PAHs. Nevertheless, metabolite results prove U. cordatus as excellent bioindicator for evaluating environmental quality in mangrove areas as related to PAHs and oil contamination.     

The effects of cadmium-accumulated chlorella on the reproduction of Moina macrocopa (cladocera)

Chlorella cultured for 6 days in a medium containing cadmium at 0.02, 0.1, and 0.5 ppm accumulated approximately 14, 70, and 340 μg/g (in dry wt) of cadmium, respectively. These chlorella were supplied as food to Moina macrocopa everyday after washing with artificial soft water. Reproductive impairment was not observed in M. macrocopa fed chlorella containing 14 μg/g of cadmium. Slight reproductive impairment was observed in M. macrocopa fed chlorella containing 70 gmg/g of cadmium at initial and late stages of the experiment. However, survival rate, growth rate, and reproductive rate were significantly affected in M. macrocopa fed chlorella containing 340 μg/g of cadmium. The accumulation level of cadmium in chlorella which causes 50% reproductive impairment of M. macrocopa was estimated to be 280 μg/g (in dry wt). The cadmium accumulation level in M. macrocopa fed these chlorella was measured throughout the 8-day experiment. The rate of accumulation of cadmium by Moina through chlorella was considerably lower than that through the water containing dissolved cadmium.     

Determination of urinary metabolites of polycyclic aromatic hydrocarbons (PAH) for the risk assessment of PAH-exposed workers

A method for the simultaneous determination of urinary phenanthrene, fluoranthene, pyrene, chrysene and benzo[a]pyrene metabolites has been developed for individual risk assessment at polycyclic aromatic hydrocarbon (PAH)-burdened workplaces. The concentration of urinary metabolites as a measure for individual PAH exposure takes account not only of PAH masses resorbed by the respiratory tract but also those incorporated percutaneously. The method allows the determination of 25 different components with a low margin of error; the individual metabolite profiles thereby allow conclusions on the individual characteristics of PAH-oxidizing enzymes (monooxygenases). The coefficients of variation are lower than 10%. After enzymatic treatment of the urine with glucuronidase and arylsulfatase one part of the benzene or toluene extract is treated with diazomethane to convert phenols into methylethers, while another part is used to convert dihydrodiols into phenols. After further purification the metabolites are determined by means of a combination of gas chromatography and mass spectrometry. The PAH exposure of coke plant workers during several consecutive days resulted in fairly constant individual urinary metabolite profiles which, however, exhibited significant inter-individual variability. This held true also for Wistar rats exposed to tar pitch aerosol on 5 days during a period of 10 days. It was also demonstrated that in the case of coke plant workers there is a correlation between inhaled PAH and metabolites excreted. Mass relationships between inhaled PAH and metabolites excreted were found to differ from one individual to another. Received: 10 October 1995 / Accepted: 26 February 1996     

Urine and Plasma Metabolome of Healthy Adults Consuming the DASH (Dietary Approaches to Stop Hypertension) Diet: A Randomized Pilot Feeding Study

We aimed to identify plasma and urine metabolites altered by the Dietary Approaches to Stop Hypertension (DASH) diet in a post-hoc analysis of a pilot feeding trial. Twenty adult participants with un-medicated hypertension consumed a Control diet for one week followed by 2 weeks of random assignment to either Control or DASH diet. Non-missing fasting plasma (n = 56) and 24-h urine (n = 40) were used to profile metabolites using untargeted gas chromatography/mass spectrometry. Linear models were used to compare metabolite levels between the groups. In urine, 19 identifiable untargeted metabolites differed between groups at p < 0.05. These included a variety of phenolic acids and their microbial metabolites that were higher during the DASH diet, with many at false discovery rate (FDR) adjusted p < 0.2. In plasma, eight identifiable untargeted metabolites were different at p < 0.05, but only gamma-tocopherol was significantly lower on DASH at FDR adjusted p < 0.2. The results provide insights into the mechanisms of benefit of the DASH diet.     

PCBs and Organochlorines in Tissues of Silverside (Odontesthes bonariensis) from a Coastal Lagoon in Argentina

A freshwater fish species, silverside (Odontesthes bonariensis) from Mar Chiquita coastal lagoon, Argentina, was analyzed for concentrations of several organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) in liver, gonads, mesenteric fat and muscle, and the contents of the digestive tract over several stages of sexual maturation. PCBs and OCs were detected at ng/g concentrations (wet weight) in pooled samples, with levels generally in the order of fat > liver > gonad > muscle, reflecting the differences in tissue lipid content. Lipid-normalized concentrations of the analytes were relatively consistent among tissues, except for significantly higher concentrations of PCBs (e.g., 447.7 ng/g lipid wt) in the ovaries of female silverside. DDT and its metabolites, γ-HCH, and several insecticides from the cyclodiene class, including endosulfan and endosulfan sulfate, were the predominant OCs in fish tissues and the contents of the digestive tract, reflecting recent and past pesticide use in this region. The ratio of OCs to PCBs in all tissues was >1; consistent with contamination of the region with OC pesticides. However, PCBs were dominated by penta- and hexachlorobiphenyls, which is consistent with direct (i.e., nonatmospheric) inputs. Biomagnification of penta- and hexachlorobiphenyl PCB congeners was noted in fish tissues relative to the contents of the digestive tract. Total OC and PCB concentrations in the ovaries and muscle of silverside were below concentrations associated with reproductive impairment in fish or the limits for human consumption, respectively.     

In vivo metabolism of benzo(a)pyrene in the mussel Mytilus galloprovincialis

The capacity of the mussel Mytilus galloprovincialis to metabolize benzo(a)pyrene (BaP) in vivo was investigated from a qualitative point of view. BaP metabolites extracted from digestive gland and gills of mussel injected with [³H]BaP included polar metabolites, 9–10, 4–5 and 7–8 BaP diols (17%), 1–6, 3–6 and 6–12 BaP quinones (47%), and 9, 1, and 3 BaP phenols (36%). BaP metabolites conjugated to both glucuronic acid and sulfate, and covalently bound to macromolecules in the 9000g supernatant and pellet, respectively, were measured in mussel 2, 8, 24 and 48 h after injection with [³H]BaP. These measurements have been demonstrated to evolve with time, suggesting that mussel is able to develop a well balanced phase I and phase II xenobiotic metabolism limitating the accumulation of reactive metabolites.     

Cadmium uptake by the crayfish, Orconectes propinquus propinquus (Girard)

Orconectes propinquus was exposed to 10, 100, and 1000 ppb Cd(Cl₂) containing 0.09 μCi/liter ¹⁰⁹ Cd(Cl₂) for 1.5, 4.5, 10.5, 22.5, 46.5, 94.5, and 190.5 hours. At 10 ppb, total Cd uptakes between 1.5 and 94.5 hours were not significantly different. By 190.5 hours, the organisms had accumulated a mean concentration of 18.4 ppm Cd, which was significantly higher than the concentrations accumulated at earlier times. At 100 ppb, Cd uptake at 1.5 hours was significantly less (P < 0.05) than that at 22.5–190.5 hours and uptake at 4.5 hours was significantly less than that at 94.5 and 190.5 hours. Also, uptake at 10.5 hours was significantly less than that at 190.5 hours. Uptakes were not significantly different between 22.5 and 94.5 hours; but were significantly higher than at 1.5 hours and lower than at 190.5 hours. At 1000 ppb, uptake increased with time and was significantly greater (P < 0.05) at every time interval monitored. By 190.5 hours, the organisms had accumulated a mean Cd concentration of 534.4 ppm. At all time intervals at 1000 ppb, Cd uptake was significantly higher (P < 0.01) than that at 100 and 10 ppb. Uptakes at 100 and 10 ppb were not significantly different.     

Piceatannol and Its Metabolite,Isorhapontigenin, Induce SIRT1 Expression in THP-1 Human Monocytic Cell Line

Piceatannol is a phytochemical that is present in large amounts in passion fruit (Passiflora edulis) seeds, and is an analog of resveratrol. Recently, the absorption and metabolism of piceatannol were investigated in rats, and isorhapontigenin, O-methyl piceatannol, was detected as a piceatannol metabolite in rat plasma. To elucidate the function of piceatannol and its metabolites, we investigated the expression of sirtuin 1 (SIRT1) in THP-1 monocytic cells after treatment with piceatannol and its metabolites, and compared their effects with those of resveratrol and its metabolites. Piceatannol and resveratrol upregulated the expression levels of SIRT1 mRNA and SIRT1 protein. An extract of passion fruit seeds, which contained high levels of piceatannol, also upregulated SIRT1 mRNA expression. As for the metabolites, isorhapontigenin upregulated SIRT1 mRNA expression, whereas resveratrol glucuronides and sulfate did not affect SIRT1 expression. These findings indicate that after intake of piceatannol, not only piceatannol itself, but also its metabolite, isorhapontigenin, contributed to the upregulation of SIRT1 expression.     

Shewanella harboring antimicrobial and copper resistance genes in sea urchins (Paracentrotus lividus) from the Crozon peninsula (Brittany,France)

Shewanella is a genus of aquatic non-fermenting Gram-negative bacteria with increasing numbers of reports of infections in humans and appearance of antimicrobial resistant strains. Cases of infection show a relatively strong association with seafood consumption or exposure to seawater. This study aimed to analyze Shewanella spp. isolated from the sea urchin Paracentrotus lividus collected from the Crozon peninsula (France) with the intention of obtaining insights into the role of this genus as a reservoir of antimicrobial and heavy metal resistance genes. Five among seven Shewanella isolates were resistant to antimicrobials, mainly to broad spectrum beta-lactams. Four isolates displayed multiple resistance to at least three of these antimicrobial classes: broad spectrum beta-lactams, aminoglycosides, macrolide, quinolones and/or tetracycline. Three antimicrobial resistance genes were detected in just one isolate encoding resistance to beta-lactam (bla_SHV and bla_TEM-1) and macrolide (ermB). In addition, the copper resistance gene cusB, was observed in this isolate which is also a plasmid carrier. Another copper resistance encoding gene, copA, was found among the isolates. These results indicate that the multidrug-resistant (MDR) Shewanella isolates and resistance genes could be potential risks to public health, due to the carrying of these MDR bacteria by sea urchins through human consumption.