Seasonal changes of two biomarkers of oxidative stress (LDH, MDA) in the edible mollusc Donax trunculus (Mollusca: Bivalvia) from the Gulf of Annaba (Algeria): correlation with carbohydrate and lipid contents

The aim of the study was to determine seasonal variations of two biomarkers of oxidative stress, lactate dehydrogenase (LDH) and malondialdehyde (MDA), and their correlation with lipid-carbohydrate metabolism in the edible bivalve Donax trunculus. The samples were collected during the four seasons in 2014 at two sites in the Gulf of Annaba (northeast of Algeria): El Battah, which is some distance from any source of pollution, is considered a relatively clean site, while Sidi Salem is a site exposed to various sources of industrial, urban and harbour pollution. The results show a significant decrease in LDH activity in Sidi Salem D. trunculus compared with those at El Battah. Moreover, carbohydrate levels increased significantly in Sidi Salem. The MDA rate increased significantly in Sidi Salem relative to El Battah, while the amounts of lipid showed a significant decrease. The lipid and carbohydrate metabolism was negatively correlated with LDH and MDA. This difference between the two sites was observed for all seasons, with more effect in spring and summer. The results obtained showed that under stressful conditions due to anthropogenic factors, some physiological processes of D. trunculus can be affected. Thus, D. trunculus appears to be a suitable sentinel species for the assessment of ecotoxicological risk in the Gulf of Annaba.