Immune-enhancing activities of chondroitin sulfate in murine macrophage RAW 264.7 cells

As a representative sulfated glycosaminoglycan (GAG), chondroitin sulfate (CS) has been reported playing vital roles in the immune response in vivo and in vitro. However, limited information is available about their immune-enhancing activity. This study was to achieve more precise understandings about the immuno-stimulating activity of CS. In in vitro experiments, CS was found to significantly promote the pinocytic, phagocytic activity and ROS production of RAW264.7 cells at the dose range of 100-1000 μg/mL compared with the untreated group (p < 0.05). Further experiments showed that CS could increase the secretion levels of NO, TNF-α, IL-6 and IL-10 via activating the corresponding mRNA expression in macrophages through the toll-like receptor 2 (TLR2). These results indicated that CS could function as an immunostimulator to enhance the immune responses and might be a potential candidate for application in immunological diseases or functional foods.