Cylindrospermopsin exposure promotes redox unbalance and tissue damage in the liver of Poecilia reticulata, a neotropical fish species.

There is a growing concern regarding the adverse risks exposure to cylindrospermopsin (CYN) might exert on animals and humans. However, data regarding the toxicity of this cyanotoxin to neotropical fish species are scarce. Using the fish species Poecilia reticulata, the influence of CYN concentrations equal to and above the tolerable for drinking water may produce on liver was determined by assessing biomarkers of antioxidant defense mechanisms and correlated to qualitative and semiquantitative histopathological observations. Adult females were exposed to 0.0 (Control); 0.5, 1 and 1.5 µg/L pure CYN for 24 or 96 hr, in triplicate. Subsequently the livers were extracted for biochemical assays and histopathological evaluation. Catalase (CAT) activity was significantly increased only by 1.5 µg/L CYN-treatment, at both exposure times. Glutathione -S-transferase (GST) activity presented a biphasic response for both exposure times. It was markedly decreased after exposure by 0.5 µg/L CYN treatment but significantly elevated by 1.5 µg/L CYN treatment. All CYN treatments produced histopathological alterations, as evidenced by hepatocyte cords degeneration, steatosis, inflammatory infiltration, melanomacrophage centers, vessel congestion, and areas with necrosis. Further, an IORG >35 was achieved for all treatments, indicative of the presence of severe histological alterations in P. reticulata hepatic parenchyma and stroma. Taken together, data demonstrated evidence that CYN-induced hepatotoxicity in P. reticulata appears to be associated with an imbalance of antioxidant defense mechanisms accompanied by histopathological liver alterations. It is worthy to note that exposure to low environmentally-relevant CYN concentrations might constitute a significant risk to health of aquatic organisms.

Treatment of cosmetic industry wastewater by flotation with Moringa oleifera Lam. and aluminum sulfate and toxicity assessment of the treated wastewater.

The production of personal hygiene and body products generates wastewater with a high load of surfactants, a high chemical oxygen demand (COD), and abundant oils and greases. Aluminum sulfate (AS) and two solutions of natural coagulant from Moringa oleifera Lam. seeds prepared with a 1M NaCl solution and 1.5M NaCl solution were used. Aluminum sulfate, Moringa oleifera Lam. in 1M NaCl, and Moringa oleifera Lam. in 1.5M NaCl solutions reduced turbidity at rates 94.48%, 98.07%, and 97.87%; reduced COD at rates 46.36%, 49.15%, and 42.7%; and reduced oil and grease at rates 98.72%, 78.65%, and 97.41%, respectively. Mutagenicity tests with guppies showed a lower toxicity of Moringa oleifera Lam. extract compared with aluminum sulfate. This work shows that Moringa oleifera Lam. extract has high potential for use as an alternative to aluminum sulfate; therefore, this study will contribute to proposals for the sustainable treatment of effluents from the cosmetic industry.

Melanomacrophage response and hepatic histopathologic biomarkers in the guppy Poecilia reticulata exposed to iron oxide (maghemite) nanoparticles.

Although iron oxide nanoparticles (IONPs) have been widely used in nanomedicine and nanoremediation, their ecotoxicological effects on aquatic organisms remain unclear. In this study, the melanomacrophage center (MMC) response and hepatic histopathologic biomarkers were investigated in female guppies, Poecilia reticulata, exposed to citrate-functionalized IONPs (γ-Fe2O3) at an environmentally relevant iron concentration (0.3 mg L-1) over 21 days. The animals were collected at the beginning of the experiment and after 3, 7, 14, and 21 days of exposure. Guppies exposed to IONPs showed increases in the number, area, and perimeter of MMC when compared with the unexposed ones, especially after 7 days of exposure. The results showed an increase in the frequency of histopathologic changes in fish after 7 days of exposure to IONPs, such micro- and macro-vesicular steatosis, melanomacrophage aggregates, exudate, and hemorrhagic foci. The acute (3 and 7 days) and long-term (14 and 21 days) exposure of P. reticulata to IONPs induced high histopathologic indexes associated with circulatory disorders and inflammatory responses. Results showed that the MMC response and histopathologic index are important biomarkers to indicate the environmental impact of IONPs, confirming that the guppy P. reticulata is a target of ecotoxicity of IONPs.

Genotoxic and mutagenic assessment of iron oxide (maghemite-γ-Fe2O3) nanoparticle in the guppy Poecilia reticulata.

The environmental risk of nanomaterials (NMs) designed and used in nanoremediation process is of emerging concern, but their ecotoxic effects to aquatic organism remains unclear. In this study, the citrate-coated (maghemite) nanoparticles (IONPs) were synthesized and its genotoxic and mutagenic effects were investigated in the female guppy Poecilia reticulata. Fish were exposed to IONPs at environmentally relevant iron concentration (0.3 mg L-1) during 21 days and the animals were collected at the beginning of the experiment and after 3, 7, 14 and 21 days of exposure. The genotoxicity and mutagenicity were evaluated in terms of DNA damage (comet assay), micronucleus (MN) test and erythrocyte nuclear abnormalities (ENA) frequency. Results showed differential genotoxic and mutagenic effects of IONPs in the P. reticulata according to exposure time. The IONP induced DNA damage in P. reticulata after acute (3 and 7 days) and long-term exposure (14 and 21 days), while the mutagenic effects were observed only after long-term exposure. The DNA damage and the total ENA frequency increase linearly over the exposure time, indicating a higher induction rate of clastogenic and aneugenic effects in P. reticulata erythrocytes after long-term exposure to IONPs. Results indicated that the P. reticulata erythrocytes are target of ecotoxicity of IONPs.

A glyphosate-based herbicide induces histomorphological and protein expression changes in the liver of the female guppy Poecilia reticulata.

Glyphosate-based herbicides (GBH) are among the most common herbicides found in aquatic systems, but limited data are available about their mode of action and hepatotoxicity in fish. This study investigated the hepatotoxicity induced by GBH in the guppy Poecilia reticulata using a histopathological assessment associated with a proteomic approach. Guppies were exposed to GBH for 24 h at 1.8 mg of glyphosate L-1, corresponding to 50% of the LC50, 96 h. The results indicate that the GBH at 1.8 mg of glyphosate L-1 induce the development of hepatic damage in P. reticulata, which is exposure-time dependent. The histopathological indexes demonstrate that GBH cause inflammatory, regressive, vascular and progressive disorders in the liver of guppies. Using 2D gel electrophoresis associated with mass spectrometry, 18 proteins that changed by GBH were identified and were related to the cellular structure, motility and transport, energy metabolism and apoptosis. The results show that the acute exposure to GBH causes hepatic histopathological damage related to protein expression profile changes in P. reticulata, indicating that a histopathological assessment associated with a proteomic analysis provides a valuable approach to assess the toxic effects of GBH in sentinel fish species.

In vitro activity of 3ß-O-tigloylmelianol from Guarea kunthiana A. Juss (Meliaceae) on oogenesis and ecdysis of the cattle tick Rhipicephalus (Boophilus) microplus (Canestrini) (Acari: Ixodidae).

We evaluated the effects of 3ß-O-tigloylmelianol from Guarea kunthiana A. Juss (Meliaceae) on oogenesis, as a larvicide and on ecdysis of the larvae and the nymphs of the cattle tick Rhipicephalus (Boophilus) microplus (Canestrini) (Acari: Ixodidae). On the oogenesis' test, 48 engorged females were divided into three groups, evaluated at 24, 48 and 72 h post-treatment. Half of the females were treated with 0.01% 3ß-O-tigloylmelianol diluted in distilled water and 5% dimethyl sulfoxide (DMSO), while the other half (controls) were exposed to distilled water and 5% DMSO. After treatment, the ovaries were weighed in order to measure the gonadosomatic index (GSI) and were also subjected to standard histological technical tests. On the larvicide and ecdysis' tests, 3ß-O-tigloylmelianol was tested at concentrations of 0.01, 0.005, 0.0025 and 0.00125%. Compared with the controls, there was a reduction of GSI of approximately 50% on the treated group, which started at 48 h post treatment. Overall, the protolimonoid 3ß-O-tigloylmelianol has caused a significant reduction in the number of oocytes. It has also caused alteration of the cytoplasmic and germinal vesicle diameters. Morphological changes, such as vacuolization, chorion irregularity which has modified the oocytes' morphology as well as alterations on the yolk's granules were also observed. The compound was not larvicide, however, interfered in the ecdysis of the larvae and the nymphs. This study shows that the protolimonoid 3ß-O-tigloylmelianol from G. kunthiana acts on oogenesis and ecdysis of R. (B.) microplus, but not as larvicide, indicating that it acts on the endocrine system of the tick.

Mutagenicity and genotoxicity in gill erythrocyte cells of Poecilia reticulata exposed to a glyphosate formulation.

Poecilia reticulata were exposed to herbicide Roundup Transorb(®) for micronucleus test, nuclear abnormalities and comet assay. The exposure-concentrations were based on CL50-96 h following 0, 1.41, 2.83, 4.24 and 5.65 µL L(-1) for 24 h. Micronucleus and comets were significantly increased in the gill erythrocyte cells after herbicide exposure compared with the non-exposed group. Results showed a gradual increase in the number of damaged cells, indicating a concentration-dependent effect and that this herbicide was mutagenic and genotoxic to P. reticulata and this effect could be attributed to a combination of compounds contained in the formulation with the active ingredient glyphosate.