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.

New insight into the toxic effects of lithium in the ragworm Perinereis cultrifera as revealed by lipidomic biomarkers, redox status, and histopathological features.

Lithium (Li) is a toxic monovalent alkaline metal used in household items common to industrial applications. The present work was aimed at investigating the potential toxic effects of LiCl on the redox status, fatty acid composition, and histological aspects of the marine ragworm Perinereis cultrifera. Sea worms were exposed to LiCl graded doses (20, 40, and 80 mg/L) for 48 h. Compared with the control group, the saturated fatty acids (SFA) decreased while monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) increased upon exposure to LiCl. The increase in PUFA n-3 and PUFA n-6 was concomitant to an increase in docosahexaenoic (DHA: C22:6n-3), eicosapentaenoic (EPA: C20:5n-3), and docosapentaenoic acid (C22:5n-6) fatty acids. Results showed that LiCl-treated specimens accumulate lithium with increasing exposure gradient. Indeed, the exposure to LiCl doses promoted oxidative stress with an increase of the ferric reducing antioxidant power (FRAP), malondialdehyde (MDA), hydrogen peroxide (H2O2), advanced oxidation protein product (AOPP), and protein carbonyl (PCO) as well as the enzymatic and non-enzymatic antioxidants (non-protein thiols (NPSH), catalase (CAT), superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione S-transferase (GST), and metallothionein (MT)) levels in all treated groups. Our biochemical findings have been affirmed by the histopathological observations showing hyperplasia and loss of the intestine structure in treated specimens. Overall, our findings give new insights on the toxic effect of LiCl on the redox status of P. cultrifera body tissue and highlighted the usefulness of the FA composition as an early sensitive bioindicators to better understand LiCl mechanism of toxicity in marine polychaetes.

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.

Exposure of Mactra corallina to acute doses of lead: effects on redox status, fatty acid composition and histomorphological aspect.

The aim of this study is to elucidate the toxicity induced by PbCl2, administered in graded doses (1; 2.5; 5 mg/L), in the redox state, in the fatty acid composition and in the histological structure of Mactra corallina digestive glands. Our findings showed a progressive accumulation of Pb in the M. corallina digestive glands in all treated groups. After 5 days of treatment with PbCl2, an increase in H2O2, MDA, PCO, GSH, NPSH and MT levels was observed in the digestive glands of treated groups. Moreover, activities of antioxidant enzymes, such as GPx and CAT, increased while SOD activity decreased in all treated groups, indicating a failure of the antioxidant defense system. Furthermore, the cholinergic function was evaluated by assessing the acetylcholinesterase activity, which was inhibited in all the treated digestive glands compared to the control group. In our experiment, the levels of n-3 (Omega-3) and n-6 (Omega-6) polyunsaturated fatty acids were greatly altered in the groups treated with 5 mg/L of PbCl2 (p < 0.001). Indeed, DHA and EPA decreased significantly in the digestive glands treated with 2.5 and 5 mg/L of PbCl2, respectively. On the other hand, under exposure to the medium and high doses (2.5 and 5 mg/L), arachidonic acid (ARA) and linoleic acid (LA) significantly increased (p < 0.001). These changes in PUFA were confirmed by significant modifications in the polyene and peroxidation indices. The histological findings confirmed the biochemical results.HighlightsIntegrated parameters were used to explore the toxic effect of PbCl2 graded doses in Mactra corallina digestive gland.Metals accumulation in digestive glands of M. corallina was greatly dependent to dose of PbCl2.Metabolic and macromolecules damaging of clams digestive glands were more sensitive at higher PbCl2 doses.Fatty acids composition especially polyunsaturated fatty acids (PUFA) and essentials fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in clams digestive glands were intensively altered at higher PbCl2 doses.Inflammation responses revealed in studied tissue.

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.

The potential toxic effects of hexavalent chromium on oxidative stress biomarkers and fatty acids profile in soft tissues of Venus verrucosa.

Hexavalent chromium (chromium (VI)), a highly toxic heavy metal, is a common pollutant of aquatic ecosystems. The present study aimed to elucidate the potential toxic effects of chromium (VI) on oxidative stress biomarkers and fatty acids profile in the gills and digestive gland of Venus verrucosa, an ecologically and economically important bivalve species. Three doses of chromium (VI) (1, 10 and 100 µg.L-1) were chosen for V. verrucosa exposure during 7 days under controlled conditions. A significant increase in the levels of malondialdehyde, lipid hydroperoxides and hydrogen peroxide was observed in the gills and digestive gland of chromium (VI)-exposed V. verrucosa as compared to the control group. Furthermore, an induction of enzymatic antioxidant activities (superoxide dismutase, glutathione peroxidase and glutathione S-transferase) and an enhancement of non-enzymatic antioxidant levels (non-protein thiols, glutathione and vitamin C) were marked. An alteration of fatty acids composition was also noted following chromium (VI) exposure. The obtained results highlighted the importance of assessing oxidative damage biomarkers and fatty acids profile in the study of chromium (VI)-induced toxicity in V. verrucosa.

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.

Effects of acute mercury exposure on fatty acid composition and oxidative stress biomarkers in Holothuria forskali body wall.

Mercury is one of the most harmful pollutant that threat marine biota. This study assessed the Hg impact on the fatty acid (FA) composition and the antioxidant statues in Holothuria forskali body wall tissue. Specimens were exposed to HgCl2 graded doses (40, 80 and 160 µg L-1) for 96 h. A decrease in linoleic, arachidonic and eicosapentaenoic acid levels and an increase of docosahexaenoic acid were mainly observed at the nominal tested dose. The exposure to the upper dose promoted oxidative stress with an increase of malondialdehyde, hydrogen peroxide, advanced oxidation protein product, glutathione and non-protein thiols levels. Moreover, a decrease in catalase and an increase in superoxide dismutase and glutathione peroxidase activities were observed. Yet, an increase of the metallothionein level was registered in all treated groups. This study confirmed the Hg toxicity on the redox statue of H. forskali and highlighted the usefulness of the FA composition as an early sensitive bioindicators.