Dual oxidative stress and fatty acid profile impacts in Paracentrotus lividus exposed to lambda-cyhalothrin: biochemical and histopathological responses.

Lambda-cyhalothrin (λ-cyh) is a potential pyrethroid insecticide widely used in pest control. The presence of pyrethroids in the aquatic ecosystem may induce adverse effects on non-target organisms such as the sea urchin. This study was conducted to assess the toxic effects of λ-cyh on the fatty acid profiles, redox status, and histopathological aspects of Paracentrotus lividus gonads following exposure to three concentrations of λ-cyh (100, 250 and 500 µg/L) for 72 h. The results showed a significant decrease in saturated fatty acid (SFAs) with an increase in monounsaturated fatty acid (MUFAs) and polyunsaturated fatty acid (PUFAs) levels in λ-cyh treated sea urchins. The highest levels in PUFAs were recorded in the eicosapentaenoic acids (C20:5n-3), docosahexaenoic acids (C22:6n-3) and arachidonic acids (C20:4n-6) levels. The λ-cyh intoxication promoted oxidative stress with an increase in hydrogen peroxide (H2O2), malondialdehyde (MDA) and advanced oxidation protein products (AOPP) levels. Furthermore, the enzymatic activities and non-enzymatic antioxidants levels were enhanced in all exposed sea urchins, while the vitamin C levels were decreased in 100 and 500 µg/L treated groups. Our biochemical results have been confirmed by the histopathological observations. Collectively, our findings offered valuable insights into the importance of assessing fatty acids' profiles as a relevant tool in aquatic ecotoxicological studies.

The potential adverse effects of acrylamide on the oxidative stress response, fatty acids profile, and histopathological aspect of the Mediterranean Holothuria forskali respiratory tree.

Acrylamide (ACR), organic compound, has been widely used owing to its broad spectrum of chemical and industrial applications. This study aims at evaluating the response of the antioxidant defense system, fatty acid composition and histopathological aspect in the respiratory trees of Holothuria forskali against ACR exposure under laboratory conditions. Holothuries were exposed to 5, 10, and 20 mg L-1 ACR concentrations for 5 days. A significant increase in n-6 polyunsaturated fatty acids levels especially the arachidonic acid (ARA, C20:4n-6) and its precursor linoleic acid (LA, C18:2n-6) in ACR-treated organisms. Regarding the n-3 levels, eicosapentaenoic acid (EPA, C20:5n-3) levels were increased in treated groups despite an acute decrease in docosahexaenoic acid (DHA, C22:6n-3) levels was observed. Our results showed a significant increase in hydrogen peroxide, malondialdehyde, protein carbonyl, and metallothionein levels along with an alteration of the antioxidants status in all treated sea cucumbers. The exposure to ACR prompted the inhibition of Acetylcholinesterase activity in a concentration-dependent manner. The histopathological aspect was marked especially with the infiltration of coelomic cells which confirms our biochemical findings. Our study provided novel insights to create a link between redox status and fatty acid composition disruptions to better understand ACR-triggered toxicity.

Assessment of the impacts of glyphosate and its commercial formulation Roundup® on the respiratory tree of the sea cucumber Holothuria forskali using a multivariate biomarker approach.

In this study, the potential hazardous impacts of the technical grade glyphosate acid (GLY) and its commercial formulation roundup (RD®) were evaluated for the first time on holothurians. To do this, redox status, fatty acid (FA) profile, and histopathology aspects were assessed in the respiratory tree tissue of the sea cucumber Holothuria forskali following short-term exposure (96 h) to a series of concentrations (10, 100 and 1000 µg L-1) of GLY and RD® (glyphosate acid equivalent). Our results showed that both GLY and RD® promoted oxidative stress highlighted with an increase of hydrogen peroxide (H2O2), malondialdehyde (MDA), lipid peroxides (LOOH) and advanced oxidation protein product (AOPP) levels in all treated groups. In addition, both glyphosate forms were found to perturb the FA composition. However, changes in saturated (SFA) and polyunsaturated (PUFA) including some essential FA (LA, ARA, EPA and DHA) revealed differential compensatory/adaptive processes in H. forskali depending on the treatment. GLY and RD® were also found to modulate the enzymatic (glutathione S-transferases, glutathione peroxidase and catalase) and non-enzymatic (reduced glutathione and ascorbic acid) antioxidant defense status. Taken together, our results revealed that the commercial formulation produced more pronounced effects on H. forskali respiratory tree than the pure form. This finding was further confirmed by the histological observations.

Fatty acid profile and antioxidant status in Venus verrucosa gills as λ-cyhalothrin toxic effects.

The aim of this study was to analyze the biochemical alterations in the gills of Venus verrucosa under exposure for 6 days to three doses of lambda-cyhalothrin (λ-cyh) (100, 250, and 500 µg L-1). Malondialdehyde, lipid hydroperoxide, and hydrogen peroxide levels in the gills of treated groups increased. λ-Cyh exposure significantly increased the protein carbonyl and reduced glutathione levels in the gills of all treated groups. Moreover, the activities of superoxide dismutase and glutathione peroxidase were increased. In our study, the polyunsaturated fatty acid (FA), omega-6, eicosapentaenoic acid (C20:5n-3), and docosahexaenoic acid (C22:6n-3) were increased in the treated groups. A significant decrease in the saturated FAs, omega-3, and arachidonic acid (C20:4n-6) levels was observed. The content of monounsaturated FA was changed in the groups treated with 100 and 250 µg L-1 of λ-cyh. As a corollary, desaturase and elongase activities were significantly increased. Our study provides evidence of the underlying toxic mechanism of λ-cyh and its capacity to create oxidative stress and revealed that FA profiling is a new approach for elucidating the λ-cyh toxicity.

Redox status and fatty acid composition of Mactra corallina digestive gland following exposure to acrylamide.

Acrylamide (ACR), a ubiquitous agent, has various chemical and industrial applications, and it is found in backed or fried carbohydrate-rich food. It has been related to multiple toxicological effects, and it causes high cytotoxicity through oxidative stress. The present study aimed to investigate the potential effect of ACR toxicity administered at different concentrations (5, 10, and 20 mg/L), during 5 days, in order to evaluate the fatty acid (FA) composition and redox state in the digestive gland of Mactra corallina. The results showed, in ACR-treated clams, a significant increase in malondialdehyde, hydrogen peroxide, protein carbonyl, and metallothionein levels, as well as an alteration of the enzymatic (superoxide dismutase, glutathione peroxidase, and catalase) and non-enzymatic (reduced glutathione and ascorbic acid) antioxidant status. However, acetylcholinesterase activity was inhibited in a concentration-dependent manner. In our experiment, the n-3 (Omega-3) and n-6 (Omega-6) polyunsaturated fatty acid levels were significantly changed in all ACR-treated groups. A decrease in eicosapentaenoic acid (C20:5n-3, EPA) and docosahexaenoic acid (C22:6n-3, DHA) was observed in 10-mg/L and 20-mg/L ACR-treated groups. Nevertheless, arachidonic acid (C20:4n-6, ARA) and its precursor linoleic acid (C18:2n-6, LA) were increased. Besides oxidative stress parameters, FA composition may be an additional tool for assessing ACR contamination.