Simone Maria Teixeira de Sabóia-Morais

Histopathological assessment and inflammatory response in the digestive gland of marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dots.

Although tissue-level biomarkers have been widely applied in environmental toxicology studies, the knowledge using this approach in marine invertebrates exposed to engineered nanomaterials (ENMs) remains limited. This study investigated histopathological alterations and inflammatory responses induced by Cd-based quantum dots (QDs), in comparison with their dissolved counterparts, in the marine mussel Mytilus galloprovincialis. Mussels were exposed to CdTe QDs and dissolved Cd at the same concentration (10μg Cd L(-1)) for 14days and a total of 15 histopathological alterations and 17 histomorphometric parameters were analysed in the digestive gland along with the determination of histopathological condition indices (Ih). A multivariate analysis showed that the mussel response to QDs was more related to exposure time, inflammatory conditions (frequency of haemocytic infiltration and granulocytomas) and changes of cell-type composition (especially the rate between basophilic and digestive cells) when compared to dissolved Cd, while the response to dissolved Cd was associated with histomorphometric parameters of the epithelium and lumen of digestive tubules and increase of the atrophic tubule frequency. Both Cd forms induced higher Ih compared to unexposed mussels indicating a significant decrease in the health status of digestive gland in a Cd form and time-dependent pattern. Results indicate that the multiparametric tissue-level biomarkers in the digestive gland provide a suitable approach to assess the ecotoxicity and mode of action of metal-based ENMs in marine bivalves.

Proteomic and histopathological response in the gills of Poecilia reticulata exposed to glyphosate-based herbicide

Glyphosate-based herbicides (GBH) are one of the most used herbicide nowadays, whilst there is growing concern over their impact on aquatic environment. Since data about the early proteomic response and toxic mechanisms of GBH in fish is very limited, the aim of this study was to investigate the early toxicity of GBH in the gills of guppies Poecilia reticulata using a proteomic approach associated with histopathological index. Median lethal concentration (LC50,96 h) was determined and LC50,96h values of guppies exposed to GBH were 3.6 ± 0.4 mg GLIL(-1). Using two-dimensional gel electrophoresis associated with mass spectrometry, 14 proteins regulated by GBH were identified, which are involved in different cell processes, as energy metabolism, regulation and maintenance of cytoskeleton, nucleic acid metabolism and stress response. Guppies exposed to GBH at 1.82 mg GLIL(-1) showed time-dependent histopathological response in different epithelial and muscle cell types. The histopathological indexes indicate that GBH cause regressive, vascular and progressive disorders in the gills of guppies. This study helped to unravel the molecular and tissue mechanisms associated with GBH toxicity, which are potential biomarkers for biomonitoring water pollution by herbicides.

Effects of the 2,4-D herbicide on gills epithelia and liver of the fish Poecilia vivipara

The 2,4-dichlorophenoxyacetic acid, usually named 2,4-D is one of the most widely used herbicides in the world. Acute toxicity of 2,4-D herbicide was investigated through its effects on guppies (Poecilia vivipara Bloch et Schneider 1801). Fish were exposed to the herbicide at concentrations of 10, 20 and 40µl per liter of water for 24 hours to determine its effects on gills and liver epithelia. The estimated LC50 was 34.64µl of 2,4-D per liter of water. Histochemical analyses and Feulgens reaction were conducted to detect glycoconjugates and DNA, respectively, in gills and liver epithelia. Histochemistry revealed qualitative variations of glycoconjugates present on mucous cells and granules. The four types of mucous cells contained neutral granules, acids, or both. Increasing amounts of syalomucins were observed from the control group to the group exposed to the highest concentration of 2,4-D, suggesting increased mucous viscosity and the formation of plaques that could inhibit gas exchange and osmoregulation. Lamellar fusion observed in the group exposed to 40µl of 2,4-D suggests a defense mechanism. Hepatocytes showed vacuolization in the 10 and 20µl/L groups. The 40 µl/L group showed normal hepatocytes as well as changed ones, many Ito cells, micronuclei, and nuclear swelling. These effects may be associated with toxicity or adaptative processes to cellular stress. The data from this study indicates the importance of assessing similar risks to aquatic species and suggests that Poecilia vivipara is an adequate biological model for analysis of environmental contamination.

Morphologic analysis of developmental phases and gill ontogenesis in neotropical species Poecilia vivipara (Cyprinodontiformes: Poeciliidae) exposed to different salinities

The present study evaluated and characterized the different phases of development and the cell types present in the gill epithelium of embryos, larvae, and fingerlings of guppy (Poecilia vivipara Bloch & Schneider, 1801) specimens exposed to water with salinity ranging from 0‰ to 20‰. The development of P. vivipara was classified into eight phases. The yolk was intensely eosinophilic, with glycidic and lipidic components between phases 1 to 7. After the development of their branchial epithelium, the presence of pavement cells, mitochondria-rich cells, and mucous cells (MCs) was observed. The understanding of ontogenesis indicates the sequence of cellular origin. Only type IV MCs located in the gill rays was detected from phase 3 through phase 7. Other types of MCs were observed only when the fingerlings were exposed to salinity changes and showed to be lectin-reactive, thus indicating that P. vivipara modulates the cellular behavior when submitted to salinity changes. Exposure to variable saline concentrations did not interfere in the initial development of guppies. The presence of a yolk sac until the fingerling phase characterized this species as ovoviviparous.

Índice mitótico em células epiteliais da brânquia de Guaru (Poecilia vivipara) tratados com frações da casca do caule e da folha de pequi (Caryocar brasiliensis)

Many wild plants of the Cerrado bioma are used as medicinal plants. The pequi (Caryocar brasiliensis) is representative of those equipped with molluscicidal action against schistosomiasis. This paper sets out to verify the toxic action of pequi fractions in other aquatic animals before they are used in rivers or lakes. Analysis were made of the alterations to the mitotic index of epithelia cells in the gills of guppy (Poecilia vivipara) exposed to ethyl-acetate fraction of leaf pequi and bark. Animals exposed to ethyl-acetate fraction (leaf), no significant change was observed in the mitotic index when compared with the control group, whereas in fish exposed to ethyl-acetate fraction (bark) we detected an increase in mitotic index of the epithelia cells in two regions of the branchial filaments. Thus, ethyl-acetate fractions (leaf) could be used against schistosomiasis, given their high efficacy and low action as piscicide.

Análise tecidual e celular das brânquias de Oreochromis niloticus L. tratadas com extrato etanólico bruto e frações das folhas da pitanga (Eugenia uniflora L.) - Myrtaceae

ABSTRACT: Tissue and cell analysis of O reochromis niloticus L. gill treated with crudeethanol extract and fractions from pitanga ( Eugenia uniflora L.) leaves – Myrtaceae. Eugenia uniflora L. (Myrtaceae) is a plant found in the Cerrado biome and traditionally used in thetreatment of diarrheas, inflammations, hyperglycemia and hypertension. Previous studies haverevealed in vitro antimicrobial activity of E. uniflora. Considering its popular use, this study aimedto assess possible systemic cellular and tissue activities of the crude extract and the fractionsfrom the leaves of this plant on Oreochromis niloticus L. (Nile tilapia) gill. Thus, ethanol extractand fractions from the leaves of this plant were orally administered to the fish in their rations. After24 hours, the fish were sacrificed and the second gill arch of each fish was dissected, fixed inneutral formalin, dehydrated, embedded in paraffin and sectioned. Masson’s trichome andhematoxylin and eosin (HE) were used in the histological analyses. Qualitative analyses using alight microscope led to the conclusion that the crude ethanol extract and the fractions from

The effect of crude ethanol extract and fractions of Hyptidendron canum (Pohl ex Benth.) Harley on the hepatopancreas of Oreochromis niloticus L

Hyptidendron canum (Pohl ex Benth.) Harley is a native tree of the Brazilian Savannah. The fish Oreochromis niloticus L. was used as an experimental model to determine the bioactivity of the crude ethanol extract as well as ethyl acetate, hexanic and chloroform fractions obtained from its leaves. The plant ethanol extract and fractions were administered to the fish orally with their feed. Twenty four hours later, the fish were sacrificed and their livers dissected, fixed in neutral formalin, embedded in paraffin and sectioned. Histological analyses were performed using Massons trichrome and Haematoxylin-Eosin. Histochemical studies were performed using Feulgen, PAS (Periodic Acid Schiff) and PAS + salivary amylase and Sudan IV stain. The qualitative analysis of the material showed that both the crude ethanol extract and the fractions from H. canum induced vasoactive activity, causing vasodilation and vascular congestion, and the hexanic fraction also caused an apparent proliferation of capillaries. Hepatopancreas toxicity was evident through inflammatory processes. Pancreatic (chloroform fraction) and hepatic alterations, hemorrhagic spots and necroses were observed in fish treated with-ethanol extract and fractions. This study is the first description of the biologic action of the crude ethanol extract and the hexane, ethyl acetate and chloroform fractions in fish.

Gender-specific histopathological response in guppies Poecilia reticulata exposed to glyphosate or its metabolite aminomethylphosphonic acid: Gender-specific histopathological response in Poecilia reticulata

Ecotoxicity of glyphosate (GLY) and its metabolite aminomethylphosphonic acid (AMPA) was investigated in guppies, Poecilia reticulata. We tested the effects of these chemicals on the gills and liver of both male and female guppies using qualitative and quantitative histopathological analyses associated with histopathological condition indexes. Both genders showed similar median lethal concentration (LC50) at 96 h for GLY (68.78 and 70.87 mg l−1) and AMPA (180 and 164.32 mg l−1). However, the histopathological assessment of both fish organs exposed to sublethal concentrations of GLY (35 mg l−1) and AMPA (82 mg l−1) for 96 h showed a tissue‐ and gender‐specific histopathological response. In both exposure assays, fish presented mainly progressive changes, such as proliferation of the interlamellar epithelium, partial and total fusion of secondary lamellae. The liver showed mainly regressive changes, such as steatosis, pyknotic nuclei and high distribution of collagen fibers. Unusually large hepatocytes as degenerated cells were also detected. Histopathological changes in gills were similar for the males and females, but the liver response was different between the genders. The hepatic inflammatory changes were more common in males. The increase in the area of hepatocyte vacuoles is gender dependent with higher values in the male compared to the female guppies exposed to GLY and AMPA. Multiparametric analysis indicated that the male guppies are more sensitive than females, particularly in the presence of AMPA. Our study shows that the histopathological assessment associated with gender‐specific response can be successfully used in ecotoxicological assessment of GLY and the metabolite AMPA. Copyright

Análise do desenvolvimento e das glicoproteínas presentes nos folículos ovarianos de Poecilia vivipara (Cyprinodontiformes, Poeciliidae)

The morphofunctional aspects of oogenesis of Poecilia vivipara were studied aiming to understand the reproductive biology and development of species with internal fertilization, particularly those belonging to the family Poeciliidae. The stages of gonadal maturation and follicular development were characterized using mesoscopic, histological, histochemical, and lectin cytochemical analyses. Through mesoscopic evaluation the ovarian development was classified in six phases of development: immature, in maturation I, in maturation II, mature I, mature II, and post-spawn. Based on microscopic examination of the ovaries, we identified the presence of oocytes types I and II during the previtellogenic phase and types III, IV, and V during the vitellogenic phase. As oogenesis proceeded the oocyte cytosol increased in volume and presented increased cytoplasmic granule accumulation, characterizing vitellogenesis. The zona radiata (ZR) increased in thickness and complexity, and the follicular epithelium, which was initially thin and consisting of pavimentous cells, in type III oocytes exhibited cubic simple cells. The histochemical and cytochemical analyses revealed alterations in the composition of the molecular structures that form the ovarian follicle throughout the gonadal development. Our study demonstrated differences in the female reproductive system among fish species with internal and external fertilization and we suggest P. vivipara can be used as experimental model to test environmental toxicity.

Composition and Chemical Variability in the Essential Oils of Hyptidendron canum (Pohl ex Benth.) Harley

Abstract The leaves and inflorescences of the ornamental and medicinal aromatic plant Hyptidendron canum were collected from four sites in the Brazilian Cerrado and their essential oils were analyzed by GC and GC/MS. Results obtained by Principal Component and Cluster analysis indicated a high chemovariability in the oils from different sites. Ses-quiterpene hydrocarbons (42.6–94.6%) were the main group of volatiles, although differences in quantities of the major constituents were observed, mainly β-caryophyllene (6.0–41.6%) and amorpha-4,7(11)-diene (6.1–30.1%), and bicyclogermacrene (3.7–24.8%) with the highest levels in leaves from Bela Vista and inflorescence from the Silvânia site, respectively. On the other hand, sabinene (0–11.7%) and β-copaene-4α-ol (0–10.3%), and δ-3-carene (0–13.0%) showed the highest percentages in oil inflorescences from the Silvânia and Hidrolândia populations. High amounts of α-humulene (1.4–13.9%) and carotol (0–12.4%) were observed in leaf oils from Silvânia and Hidrolândia, respectively.