Effect of Phlorotannins Isolated from the Ethyl Acetate Fraction of Ecklonia stolonifera on Peritoneal Macrophage Polarization

Inflammation is a protective response to infection or injury. However, prolonged inflammation can contribute to the pathogenesis of many diseases, such as cancer, diabetes, arthritis, atherosclerosis, and Alzheimer's disease. Recent studies have shown that activated macrophages, inflammatory effector cells, can react to tissue insults in a polarized manner, in which their phenotypes are polarized into two major subtypes, categorized as M1 or M2. Classical M1 activation involves the production of pro-inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor (TNF)-${\alpha}$, and free radicals, while M2 or alternative activation is an anti-inflammatory phenotype involved in homeostatic processes, such as wound healing, debris scavenging, and the dampening of inflammation via the production of very low levels of pro-inflammatory cytokines and high levels of anti-inflammatory mediators, including IL-10. As part of our ongoing effort to isolate anti-inflammatory compounds from seaweeds, we investigated the effects of phlorotannins isolated from the brown alga Ecklonia stolonifera on macrophage polarization. Mouse peritoneal macrophages were treated with various concentrations of the extracts, and real-time RT-PCR analyses were performed to examine the expression of polarization markers: IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ for M1 and arginase-1, peroxisome proliferator-activated receptor (PPAR)-${\gamma}$, found inflammatory zone-1 (Fizz-1), chitinase 3-like 3 (Ym1), and$Kr{\ddot{u}}ppel$-like factor 4 (Klf-4) for M2. The pretreatment of cells with eckol, dieckol, and phlorofucofuroeckol-A (PFF-A), isolated from the ethyl acetate fraction of E. stolonifera ethanolic extract, potentiated the anti-inflammatory M2 phenotype of the macrophages. These results indicate that phlorotannins derived from E. stolonifera can be used to enrich macrophages with markers of the M2 anti-inflammatory state.

복강대식세포의 염증성 표현형에 대한 곰피(Ecklonia stolonifera) 유래 Phlorotannins의 효과