The activation effects of fucoidan from sea cucumber Stichopus chloronotus on RAW264.7 cells via TLR2/4-NF-κB pathway and its structure-activity relationship

• Published in: Carbohydrate polymers 2021-10, Vol.270, p.118353-118353, Article 118353
• Main Authors: Jiang, Shuxin, Yin, Huanan, Li, Rui, Shi, Weiwei, Mou, Jiaojiao, Yang, Jie
• Format: Article
• Language: English
• Subjects: Fucoidan; Raw264.7 cells; Stichopus chloronotus; Structure-activity relationship; TLR2/4-NF-κB pathway
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2021.118353

Sea cucumber Stichopus chloronotus is a traditional tonic food with high nutritive value in Southern China. Fucoidan from sea cucumber Stichopus chloronotus (Fuc-Sc) is its main bio-active polysaccharide, the immune-activation effects of which have been fully investigated on RAW264.7 cells in the present study. The results indicated that Fuc-Sc could stimulate the RAW264.7 cells by promoting the production of NO, TNF-α, IL-6 and IL-10. Western blot and RT-PCR analysis revealed that TLR4 and TLR2 were involved in the recognition of Fuc-Sc and activation of downstream NF-κB signal pathway. Moreover, the chemical structure parameter molecular weight showed obvious impact on the stimulation effects of Fuc-Sc on NO production. Degraded product of Fuc-Sc with weight average molecular weight of 113.1 × 104 Da exhibited higher activities than that of intact Fuc-Sc, suggesting the existent of optimum chain length to exert its highest activities. Taken together, Fuc-Sc exerted its immunostimulating activity via TLR2/4 activation of NF-κB pathway and showed potentials to be a good immunoadjuvant. •Fuc-Sc induces the production of proinfammactory factors from RAW264.7 cells.•Fuc-Sc activates RAW264.7 cells via TLR2/4-NF-κB pathway.•The molecular weight of Fuc-Sc shows obvious impact on its stimulated NO production.