Improvement of immune function by means of Conger conger extract in an in vivo rat model of cold stress

Abstract

The sea eel, Conger conger is a common and widespread species all around the Adriatic, Mediterranean, North Atlantic and northern Africa's coasts. Biochemical analyses of fatty acid compositions in this species show a great content of polyunsaturated fatty acids (PUFAs), especially EPA and DHA, which makes its fatty acid profile more favourable. Since in recent years, n-3 PUFA have been acclaimed for greater potency in the amelioration of heart, cardiovascular disorders and immune functions, an acute experimental model of immune system stress induced by exposure of rats to a hypothermic shock (4 h at 4°C) was used to determine the capacity of Conger conger extracts to restore the function of peripheral T lymphocytes. After hypothermic shock, blood samples were collected and 100 µl of whole blood were exposed to 20 µg/ml and 100 µg/ml of Conger conger extracts and cultured in RPMI complete medium during 4, 16 and 24 h, respectively. After incubation, blood was stained with specific anti-rat CD4, CD8, CD25 and CD28 monoclonal antibodies at each time point. The percentages of antigen expression indicate significant differences in the group treated with both 20 µg/ml and 100 µg/ml mainly in CD4 and CD28 expressions, as compared to controls, suggesting an up-regulation of the immune function.