For several years, industrialization and its activities have undoubtedly raised our standard of living, but this has come at the expense of environmental pollution. Chromium (Cr) stands out among the various contaminants resulting from industrial activities. This metal primarily exists in trivalent and hexavalent forms, which can have significant toxic effects on organisms. The hexavalent form is known as an aquatic contaminant due to its widespread use in industries such as refineries, petroleum combustion, wood preservation, and power plants. Cr is a major concern in ecotoxicology due to its non-biodegradable nature, which leads to its accumulation in organisms and subsequent transfer through the food chain. Regarding this topic, the present study assessed the potential of potassium dichromate (K2Cr2O7) induced gonadotoxicity in Paracentrotus lividus. Urchin species were divided into four groups of 30 each: group 1, serving as controls; groups 2,3 and 4 exposed to K2Cr2O7 at 1, 10 and 100 µg L− 1, respectively. Results indicated that urchin exposure to different K2Cr2O7 doses contained high levels of hydrogen peroxide (H2O2) along with a strong macromolecule alteration and total antioxidant activities. At this point, malondialdehyde (MDA), lipid hydroperoxide (LOOH), in the treated gonads increased significantly mainly under 100 µg L− 1. K2Cr2O7 exposure significantly increased the metallothionein (MT) levels in the gonads of all treated groups. The exposed P. lividus also modified the gonadic antioxidant systems such as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and vitamin C (Vit C) due to K₂Cr₂O₇ toxicity. Gaz chromatography analysis identified 28 compounds, including oleic, stearic, eicosatetraenoic, and docosahexaenoic acids. The comparison of fatty acid profiles showed a change in saturated fatty acids under K2Cr2O7 exposure. Additionally, exposure of P. lividus to K2Cr2O7 lowered the monounsaturated fatty acids. Increases in levels of polyunsaturated fatty acids and the major groups mainly n-3 PUFA and n-6 PUFA were recorded under K2Cr2O7 exposure. The K2Cr2O7 effects in P. lividus were demonstrated by histopathological injuries of the gonads. These findings highlight the potential ecotoxicological impacts of chromium (VI) on marine organisms and underline the necessity for effective regulations and mitigation strategies to protect coastal ecosystems.

Differential Impacts of Potassium Dichromate on Fatty Acid Composition, Redox Status, and Histopathological Structure in Paracentrotus Lividus Gonads

期刊论文
发表日期：

2025年8月20日

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Amira Soltani,
Chaima Fouzai,
Safa Bejaoui,
Wafa Trabelsi,
Dalya Belhassen,
Rym Baati,
Nejla Soudani

摘要

For several years, industrialization and its activities have undoubtedly raised our standard of living, but this has come at the expense of environmental pollution. Chromium (Cr) stands out among the various contaminants resulting from industrial activities. This metal primarily exists in trivalent and hexavalent forms, which can have significant toxic effects on organisms. The hexavalent form is known as an aquatic contaminant due to its widespread use in industries such as refineries, petroleum combustion, wood preservation, and power plants. Cr is a major concern in ecotoxicology due to its non-biodegradable nature, which leads to its accumulation in organisms and subsequent transfer through the food chain. Regarding this topic, the present study assessed the potential of potassium dichromate (K₂Cr₂O₇) induced gonadotoxicity in Paracentrotus lividus. Urchin species were divided into four groups of 30 each: group 1, serving as controls; groups 2,3 and 4 exposed to K₂Cr₂O₇ at 1, 10 and 100 µg L^− 1, respectively. Results indicated that urchin exposure to different K₂Cr₂O₇ doses contained high levels of hydrogen peroxide (H₂O₂) along with a strong macromolecule alteration and total antioxidant activities. At this point, malondialdehyde (MDA), lipid hydroperoxide (LOOH), in the treated gonads increased significantly mainly under 100 µg L^− 1. K₂Cr₂O₇ exposure significantly increased the metallothionein (MT) levels in the gonads of all treated groups. The exposed P. lividus also modified the gonadic antioxidant systems such as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and vitamin C (Vit C) due to K₂Cr₂O₇ toxicity. Gaz chromatography analysis identified 28 compounds, including oleic, stearic, eicosatetraenoic, and docosahexaenoic acids. The comparison of fatty acid profiles showed a change in saturated fatty acids under K₂Cr₂O₇ exposure. Additionally, exposure of P. lividus to K₂Cr₂O₇ lowered the monounsaturated fatty acids. Increases in levels of polyunsaturated fatty acids and the major groups mainly n-3 PUFA and n-6 PUFA were recorded under K₂Cr₂O₇ exposure. The K₂Cr₂O₇ effects in P. lividus were demonstrated by histopathological injuries of the gonads. These findings highlight the potential ecotoxicological impacts of chromium (VI) on marine organisms and underline the necessity for effective regulations and mitigation strategies to protect coastal ecosystems.