Effect of fish oil supplementation on erythrocyte lipid pattern, malondialdehyde production and glutathione-peroxidase activity in psoriasis.

Erythrocytes from psoriatic patients have a significant increase in polyunsaturated fatty acids (p less than 0.001) especially in arachidonic acid (p less than 0.001). Glutathione peroxidase activity, in both erythrocytes and platelets, was stimulated when compared with normal cells (p less than 0.001, less than 0.02, respectively) and the production of malondialdehyde was also increased in psoriasis (p less than 0.01). The level of plasma selenium was significantly reduced (52.80 vs 72.49 ng/ml; p less than 0.001). alpha-Tocopherol and retinol were both normal in plasma of psoriatics. After two months of fish oil supplementation, the erythrocyte lipid pattern was changed, eicosapentaenoic and dochesaenoic acids substituting the arachidonate in the membrane. A reduction in malondialdehyde (p less than 0.01), a prolongation of bleeding time (p less than 0.05) and a further stimulation of glutathione-peroxidase (p less than 0.001) in both erythrocytes and platelets was also found.