Immunomodulating activity of Sargassum horneri extracts in RAW264.7 macrophages

Purpose: Sargassum horneri (S. horneri) is a species of brown macroalgae that is common along the coast of Japan and Korea. The present study investigated the immuno-modulatory effects of different types of S. horneri extracts in RAW264.7 macrophages. Methods: S. horneri was extracted by three different methods, hot water extraction, 50% ethanol extraction, and supercritical fluid extraction. Cell viability was then measured by MTT assay, while the production levels of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and nitric oxide (NO) were measured by enzyme-linked immunosorbent assay and Griess assay, respectively. The expression and activation levels of inducible NO synthase (iNOS), mitogen-activated protein kinase (MAPK) and nuclear factor ${\kappa}B$ ($NF-{\kappa}B$) were examined by western blot analysis. Results: The three different S. horneri extracts were nontoxic against RAW 264.7 cells up to $50{\mu}g/mL$, among which treatment with hot water extract (HWE) of S. horneri significantly enhanced the production of TNF-${\alpha}$, IL-6, and NO in a dose-dependent manner. Hot water extract of S. horneri also increased the expression level of iNOS, suggesting that up-regulation of iNOS expression by HWE of S. horneri was responsible for the induction of NO production. In addition, treatment of RAW 264.7 macrophages with HWE of S. horneri increased the phosphorylation levels of ERK, p38 and JNK. Furthermore, the activation and subsequent nuclear translocation of $NF-{\kappa}B$ was enhanced upon treatment with HWE of S. horneri, indicating that HWE of S. horneri activates macrophages to secrete TNF-${\alpha}$, IL-6 and NO and induces iNOS expression via activation of the $NF-{\kappa}B$ and MAPKs signaling pathways. Conclusion: Taken together, these findings suggest that HWE of S. horneri possesses potential as a functional food with immunomodulatory activity.

RAW264.7 대식세포에서 괭생이 모자반 추출물의 면역활성 증진 효과

본 연구에서는 모자반목 모자반과 갈조류인 괭생이 모자반의 3가지 서로 다른 추출물의 면역활성 가능성을 비교연구하기 위하여 RWA264.7 대식세포에 서로 다른 괭생이 모자반 추출물을 처리하여 $TNF-{\alpha}$, IL-6 및 NO 분비능과 MAPK 신호전달경로 및 $NF-{\kappa}B$ 활성화 수준을 측정하였다. 괭생이 모자반 열수추출물, 주정추출물, 그리고 초임계추출물 중 괭생이 모자반 열수추출물이 세포독성은 없는 농도 ($50{\mu}g/mL$)에서 $TNF-{\alpha}$, IL-6의 생성뿐 아니라 iNOS 활성화를 통한 NO 분비를 촉진하였다. 이러한 괭생이 모자반 열수추출물의 면역증진 효과는 MAPK 신호전달경로 및 $NF-{\kappa}B$ 활성화를 통해 이루어지고 있음을 확인하였다. 본 연구결과는 괭생이 모자반 열수추출물의 면역활성 증진 가능성을 제시하여 향후 대식세포의 활성 유도를 통한 면역증진 치료에 유용하게 사용될 수 있음을 보여주는 것이다.