Publications by authors named "Marcela Muñoz-Peñuela"

6 Publications

  • Page 1 of 1

Eutrophication effects on fatty acid profiles of seston and omnivorous fish in tropical reservoirs.

Sci Total Environ 2021 Mar 20;781:146649. Epub 2021 Mar 20.

Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 101, SP 05508-090, Brazil.

It has been postulated that eutrophication causes replacement of n3 highly unsaturated fatty acids (n3 HUFA) rich taxa, such as Bacillariophyta, Cryptophyta and Dinophyta, with taxa poor in these fatty acids (FA), such as Chlorophyta and Cyanobacteria. Such a change in community composition at the basis of the food web may alter the FA composition of consumer tissues. Here, we investigated the effects of eutrophication on phytoplankton composition and FA profiles of seston and muscle of two omnivorous fish species (Astyanax fasciatus and Astyanax altiparanae) from reservoirs of different trophic status in Southeast Brazil. The phytoplankton composition and seston FA profiles reflected the degree of eutrophication at most of the studied sites. Three of the five most eutrophic sites were dominated by cyanobacteria and had the highest saturated fatty acid (SFA) and lowest polyunsaturated fatty acid (PUFA) relative contents among all sites. In contrast, the remaining two sites presented a higher phytoplankton diversity and higher relative contribution of sestonic PUFAs with 18 carbons (C18) and HUFAs than less eutrophic systems. However, there were no clear effects of sestonic FA profiles on the FA profiles of muscle of both fish species. A higher percentage of n3 HUFAs was found in the fish samples from a hypereutrophic and cyanobacteria dominated reservoir than in those from sites with a more diverse phytoplankton community in which fish mainly showed higher percentages of C18 PUFA. These results suggest a lack of a direct relationship between the degree of eutrophication and the percentage of n3 HUFAs in both fish species, which can be caused by specific characteristics of the reservoirs that may modulate eutrophication effects. Therefore, consumer FA biochemistry seemed to be dictated by their ability to select, accumulate, and modify dietary FAs, rather than by the eutrophication degree of the studied tropical reservoirs.
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http://dx.doi.org/10.1016/j.scitotenv.2021.146649DOI Listing
March 2021

Nonsteroidal anti-inflammatory drugs act as endocrine disruptors in Astyanax lacustris (Teleostei: Characidae) reproduction: An ex vivo approach.

Aquat Toxicol 2021 Jan 29;232:105767. Epub 2021 Jan 29.

Escola de Ciências da Saúde, Universidade Anhembi Morumbi - R. Dr. Almeida Lima, 1134 - Parque da Mooca, 03164-000, São Paulo, SP, Brazil. Electronic address:

Pharmaceutical products can act as endocrine-disrupting compounds (EDCs), affecting the physiological processes of animals, such as development or reproduction. This study aimed to investigate the influence of different concentrations of nonsteroidal anti-inflammatory drugs (NSAIDs) diclofenac (DCF) and ibuprofen (IBU) alone and mixed (MIX) on gonadotropin gene expression and gonadal steroid release using Astyanax lacustris pituitary and testes explant systems, respectively. The explant organs were maintained for 12 h in Leibovitz (L-15) medium supplemented with 0, 0.1, 1, 10, 100, and 1000 ng L of DCF, IBU, and MIX (ratio 1:1 of the same concentrations of DCF and IBU alone) and gonadotropin releasing-hormone (cGnRH2) stimulation in pituitary explants and human chorionic gonadotropin (hCG) stimulation in testes explants. The pituitary glands and the media from the testicular explants were collected for gene expression analysis including the β subunit of the follicle-stimulating hormone (fshβ) and luteinizing hormone (lhβ) and secreted gonadal steroid concentration analysis, respectively. Both DCF and IBU (alone and mixed) decreased pituitary gene expression of fshβ and lhβ and this inhibitory effect was evident even at low concentrations. In the testes, DCF and IBU did not change the levels of estradiol, and both pharmaceuticals increased the release of 11-ketotestosterone at low doses, while only IBU decreased the levels of testosterone in all concentrations. IBU's inhibitory effect in the testes was not triggered by the mixture of the two drugs. These results suggest that NSAIDs, may interfere in fish reproduction by acting as EDCs, thereby negatively affecting A. lacustris spermatogenesis and maturation.
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http://dx.doi.org/10.1016/j.aquatox.2021.105767DOI Listing
January 2021

Integrated use of biomarkers to evaluate the reproductive physiology of Astyanax fasciatus and Hoplias malabaricus males (Teleostei: Characiformes) in polluted reservoirs.

Ecotoxicol Environ Saf 2021 Jan 22;208:111502. Epub 2020 Oct 22.

Laboratório de Metabolismo e Reprodução de Organismos Aquáticos, Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Trav.14, nº 321, 05508-090 São Paulo, SP, Brazil. Electronic address:

The reproductive physiology of fish can be changed by the presence of pollutants in the water, which act as endocrine disrupting compounds (EDC). We evaluated the impacts of water contaminants in polluted reservoirs acting as possible EDC on the reproductive physiology of Astyanax fasciatus and Hoplias malabaricus males. We used biomarkers with different levels of biological organization. Hoplias malabaricus adult males were collected in the summer and winter at five different sites in the Tietê River Basin: the Ponte Nova reservoir (PN), considered a reference site due to the low anthropogenic influence; the Billings reservoir (BIL) at two different branches; and the Guarapiranga reservoir (GUA) at two different branches. Astyanax fasciatus adult males were collected at PN and BIL. BIL and GUA are subjected to great anthropogenic action. We analyzed gonadal histomorphology, testosterone (T), 11-ketotestosterone (11-KT), estradiol (E) plasma levels, and gene expression of hepatic vitellogenin (vtgA) and pituitary follicle stimulating hormone (fshβ). In the PN reservoir (reference), the biomarkers analyzed in both species did not differ between the periods analyzed. This is an evidence that the animals keep the same reproductive activity during both seasons. The changes in the plasma concentration of gonadal steroids in both species in polluted reservoirs suggest the presence of EDC compounds in the water and/or adjusts of the physiological setpoint to allow the reproduction in such adverse conditions. The use of vtgA as biomarker suggests the presence of estrogenic compounds, mainly in BIL, but with a more evident response of H. malabaricus. However, even considering physiological changes, both species present testes during the maturation phase that allow the reproduction in an environment with a high degree of pollution.
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http://dx.doi.org/10.1016/j.ecoenv.2020.111502DOI Listing
January 2021

Diclofenac and caffeine inhibit hepatic antioxidant enzymes in the freshwater fish Astyanax altiparanae (Teleostei: Characiformes).

Comp Biochem Physiol C Toxicol Pharmacol 2021 Feb 10;240:108910. Epub 2020 Oct 10.

Universidade de São Paulo, Instituto de Biociências, Departamento de Fisiologia, Laboratório de Metabolismo e Reprodução de Organismos Aquáticos, Cidade Universitária, São Paulo, Brazil.

Although concentrations of pharmaceutical compounds in aquatic ecosystems are low, they can cause toxic effects on organisms. The aim of this study was to evaluate the effects of diclofenac (DCF), a non-steroidal anti-inflammatory drug, and caffeine (CAF), a central nervous system stimulant, both alone or combined, in Astyanax altiparanae males under acute exposure (96 h), measuring neurotoxicity biomarkers, antioxidant response and damage at biochemical and cellular levels. DCF concentration in water, separated and combined, was 3.08 mg L and that of CAF was 9.59 mg L. To assess neurotoxicity, brain and muscle acetylcholinesterase (AChE) activities were measured. To evaluate oxidative stress, the enzymatic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione S-transferase (GST), as well as lipoperoxidation (LPO), were analyzed in liver and gills. Activity of hepatic cyclooxygenase (COX) was also evaluated. Genotoxicity was assessed in blood using comet assay and micronucleus test, as well as nuclear abnormalities. DCF and CAF, alone or combined, had neither effect on AChE activity, nor in the activity of SOD, CAT, GPx and GST in gills. In liver, DCF inhibited SOD and GPx activity, CAF inhibited CAT activity, the mixture inhibited SOD and GST activity; although only fish exposed to CAF showed increased hepatic LPO. Under these experimental conditions, no effect on COX activity was observed, nor cytotoxic and genotoxic damage. The most pronounced effects were caused by the drugs separately, since both compounds altered the enzymes, but only CAF triggered LPO, showing more harmful effects.
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http://dx.doi.org/10.1016/j.cbpc.2020.108910DOI Listing
February 2021

Endocrine disruptive action of diclofenac and caffeine on Astyanax altiparanae males (Teleostei: Characiformes: Characidae).

Comp Biochem Physiol C Toxicol Pharmacol 2020 May 28;231:108720. Epub 2020 Jan 28.

Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, Trav.14, n° 321, 05508-090 São Paulo, SP, Brazil. Electronic address:

Diclofenac (DCF) and caffeine (CAF) are persistent pharmaceuticals that occur in mixtures in the aquatic ecosystems causing effects in the reproductive physiology of aquatic organisms. This study evaluated the physiological reproductive responses of Astyanax altiparanae males exposed to nominal concentrations of DCF (3.08 mg L) and CAF (9.59 mg L) separately and combined, for 96 h. The steroids profile, estrogenic biomarker vitellogenin (vtgA), testes and liver morphology, and also mortality of males were assessed. DCF and CAF degradation was 5% of the initial concentration for 24 h. The LC of the DCF and CAF were 30.8 mg L and 95.9 mg L, respectively. Males exposed to DCF and CAF exhibited a reduction of 17β-Estradiol (E) concentration compared to control (CTL). Similarly, testosterone (T) was also reduced in the DCF treatment, but this response was not observed in 11-Ketotestosterone (11-KT). Males exposed to DCF + CAF combined did not exhibit differences in T, E and 11-KT steroids. The vtgA gene expression and the sperm concentration did not change among the treatments. Moreover, acute exposure revealed a hypertrophy of hepatocytes cells in the DCF and DCF + CAF treatments. In conclusion, DCF and CAF, isolated, exhibit an endocrine disruptive activity in A. altiparanae male, an opposite response observed with the mixture of both compounds that abolishes the endocrine disruptive effects. DCF seems to be more toxic for this species, altering also hepatocytes morphology.
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http://dx.doi.org/10.1016/j.cbpc.2020.108720DOI Listing
May 2020

Water temperature and acid pH influence the cytotoxic and genotoxic effects of aluminum in the freshwater teleost Astyanax altiparanae (Teleostei: Characidae).

Chemosphere 2019 Apr 20;220:266-274. Epub 2018 Dec 20.

Universidade de São Paulo, Institute of Biosciences, Department of Physiology, Laboratory of Metabolism and Reproduction of Aquatic Organisms - LAMEROA; Matão Street, 14 lane, number 101 - room 220, Cidade Universitária, São Paulo, SP, Brazil. Electronic address:

The toxicity of metals, including aluminum (Al), can be potentiated by temperature and acid pH, a concern in view of the current global warming scenario. The aim of this study was to evaluate the bioconcentration of Al in the testes and semen of Astyanax altiparanae and the potential of this metal, at different environmental temperatures and acid pH, to cause cytotoxicity and genotocixity in erythrocytes and spermatozoa. A. altiparanae males were divided into nine experimental groups: at each of three different water temperatures (20, 25 and 30 °C), the fish were exposed to a neutral pH, an acid pH and acidic water containing Al (0.5 mg.L). The fish were subjected to subacute, semi-static exposure and sampled at 24 and 96 h. After each exposure period the comet assay (blood and semen) and micronucleus test (blood) were performed. Bioconcentration of Al was evaluated in the testes and semen. Exposure time and temperature influenced the Al bioconcentration pattern in the testes. Al concentration in the semen was higher in fish exposed at 20 and 25 °C (24 h). The DNA fragmentation score for the semen and blood was higher in fish exposed to Al at 20 (24 h) and 30 °C (96 h). The frequency of nuclear abnormalities in erythrocytes was higher in the group exposed to Al at 30 °C (96 h). It was concluded that Al bioconcentrates in the testes and semen of A. altiparanae at different temperatures and is potentially cytotoxic and genotoxic to erythrocytes and spermatozoa in this species.
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http://dx.doi.org/10.1016/j.chemosphere.2018.12.143DOI Listing
April 2019