(P30-017-23) The Antioxidant and Anti-Inflammatory Effects of Sargassum hemiphyllum in LPS-Stimulated Macrophage Cells

Objectives: Sargassum Hemiphyllum Extract (SHE) has anti-inflammatory and antioxidant effects in Lipopolysaccharide(LPS)-induced macrophage cells, and inhibits the expression of inflammatory cytokines by interfering with the inflammation-related signaling system (NF-κB, MAPK pathway) in inflammatory cells and will increase the expression of antioxidant-related markers.

Methods: RAW 264.7 macrophage cells were induced by LPS to increase the expression of inflammatory cytokines(TNFα, IL-1β, iNOS, COX2). Real-time PCR and Western blot experiments were performed to measure the expression of inflammatory cytokines at mRNA and protein levels.
Furthermore, BMDM cells were induced with LPS and Interferon Gamma (IFN-γ) to differentiate into inflammatory cells, and the anti-inflammatory effect of SHE was confirmed.
The cell cycle was measured using a Muse Cell Cycle kit (EMD Millipore, Billerica, MA, USA)

Results: In RAW 264.7 cell macrophages stimulated with LPS, treatment of SHE increased mRNA expression of antioxidant-related enzymes SOD1 and CAT, while expression of antioxidant-related regulator nuclear factor erythroid 2-related factor 2 (Nrf2) was not increased. In LPS and (Interferon Gamma) IFN-γ-induced RAW 264.7 cell macrophages and bone marrow-derived macrophages (BMDMs), the mRNA expression of CD86, the M1 polarization gene, and pro-inflammatory cytokines (TNFα, IL1β, iNOS, COX2) mRNA expression were increased. However, the Sargassum Hemiphyllum hexane fraction (HEX) at concentrations of 25, 50, and 100 μg/mL suppressed the mRNA expression of CD86 and pro-inflammatory cytokines. LPS stimulation arrested macrophage cell cycling. LPS decreased the G0/G1 phase of the macrophage cell and increased the S phase. After that, the G0/G1 phase recovered and the S phase decreased by treatment with SHE at the concentrations of 25 and 50 μg/mL.

Conclusions: The various inflammatory cytokines expressed in inflammation-induced cells induced by LPS were sufficiently decreased by SHE, and SHE also had an effect on the inflammation expression mechanisms (NF-κB, MAPK). In addition, the effect of SHE inducing a decrease in the S phase of the cell cycle indicates that SHE may be involved in DNA synthesis during the cell growth cycle.

Funding Sources: This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT).