Anti‑tumor effects of an aqueous extract of Ecklonia cava in BALB/cKorl syngeneic mice using colon carcinoma CT26 cells

Ecklonia cava (E. cava) is well known as one of edible alga that contains various unique polyphenols. The anti-tumor activity of an aqueous extract of E. cava (AEC) against colon carcinoma was evaluated by analyzing the alterations in tumor growth, histopathological structure and molecular mechanisms in CT26 tumor-bearing BALB/cKorl syngeneic mice after administrating AEC for five weeks. AEC contained high total phenolic contents and demonstrated significant scavenging activity against 2,2-diphenyl-1-picrylhydrazyl radicals. Marked anti-tumor effects were demonstrated in the AEC-treated CT26 cells. In the in vivo syngeneic model, the AEC treatment decreased the volume and weight of CT26 tumors, and expanded the necrotic region in the hematoxylin and eosin stained tumor sections. The inhibitory effects of AEC on tumor growth were reflected by the increased level of apoptotic proteins, inhibition of cell proliferation, suppression of metastasis ability and increase in tumor-suppressing activity in CT26 tumor-bearing BALB/cKorl syngeneic mice. The potential function of phlorotannin (PT), one of the primary active compounds in AEC, was demonstrated by the increased cytotoxicity, apoptosis and suppression of cell proliferation in PT-treated CT26 cells. Overall, the results of the present study provide novel scientific evidence that AEC can suppress the growth of CT26 colon cancer by activating apoptosis, suppressing cell proliferation, inhibiting cell migration and enhancing the tumor-suppressing activity.