Enzymatic extract from Ecklonia cava induces the activation of lymphocytes by IL-2 production through the classical NF-κB pathway.

Activated nuclear factor-kappa B (NF-κB), a well-known transcription factor, leads to the development, differentiation, and proliferation of T and B lymphocytes and the secretion of cytokines by the classical pathway. We have examined here whether an enzymatic extract (ECK) from the brown seaweed, Alariaceae Laminariales Ecklonia cava may contribute to activating lymphocytes through the NF-κB pathway for participation in immune responses. In our study, ECK dose-dependently enhanced the proliferation of lymphocytes. ECK significantly increased the phosphorylation of inhibitors of κB at 0.25 and 0.5 h of exposure, followed by its gradual decrease. In addition, NF-κB p65 was gradually activated, and its binding to nuclear deoxyribonucleic acid was observed from 0.25 h after stimulation (up to 0.5 h). Further experiments showed that the application of N-p-tosyl-L: -phenylalanine chloromethyl ketone, an NF-κB inhibitor, significantly blocked ECK-induced lymphocyte's proliferation and the interleukin (IL)-2 productions. Accordingly, our results suggest that ECK increases the production of IL-2 through the activation of NF-κB then induces the proliferation of lymphocytes with the coordinated stimulation of IL-2.