This study investigated the immune-enhancing effects of polysaccharides extracted from Gloiopeltis furcata (red seaweed) with different molecular weights. A crude polysaccharide mixture was hydrolyzed using acid treatment (0.1 N HCl) and three molecular weight fractions were generated and filtered using centrifugation: (≤10 kDa, 10 to 100 kDa, and 100 kDa. Nitric oxide (NO) production in RAW264.7 cells treated with 0.01-0.5 μg/mL polysaccharides ≥100 kDa was 12.28-19.05 μM. Treatment with polysaccharides ≥100 kDa increased cytokine levels, including TNF-α and IL-6 levels, in a dose-dependent manner. Polymerase chain reaction analysis also revealed marked increases in iNOS and COX-2 mRNA expression levels. These findings lead us to conclude that macrophage activation induced by polysaccharides ≥100 kDa was greater than that induced by polysaccharides ≤10 kDa or between 10 and 100 kDa. The polysaccharides ≥100 kDa extracted from Gloiopeltis furcata investigated herein are potentially useful as natural immune-enhancing agents. These findings provided further insights into the potential use of ≥100 kDa as immunopotentiator or new function food.

Introduction
 Materials and Methods
  Materials
  Extraction of crude polysaccharides
  Preparation of polysaccharides with different molecular weights
  Cell culture
  Cell proliferation
  Nitric oxide production
  Cytokines production
  PCR analysis of mRNA expression
 Results and Discussion
  Cell proliferation
  Nitric oxide production
  Cytokine production
  RT-PCR analysis of mRNA expression
 요 약
 References

• Dae-Hoon Lee(Department of Food Science and Technology, Daegu Catholic University) | 이대훈
• Joo-Heon Hong(Department of Food Science and Technology, Daegu Catholic University) | 홍주헌 Corresponding author