Low Molecular Weight, 4--Sulfation, and Sulfation at Meta-Fucose Positively Promote the Activities of Sea Cucumber Fucoidans on Improving Insulin Resistance in HFD-Fed Mice.

Abstract

Fucoidans from sea cucumber (SC-FUC) have been proven to alleviate insulin resistance in several species. However, there are few studies that clarify the relationship between their structure and bioactivity. The present study evaluated the influence of molecular weight (Mw), sulfation concentrations (Cs), and sulfation position on improving insulin resistance using SC-FUC. Results showed that fucoidans with lower Mw exerted stronger effects. Having a similar Mw,fucoidans (-FUC) with lower Cs andfucoidans with higher Cs showed similar activities. However,fucoidans (higher Cs) activity was superior to that of low-Mwfucoidans (-LFUC, lower Cs). Eliminating the effects of Mw and Cs, the bioactivity of-FUC with sulfation at meta-fucose exceeded that of-FUC with sulfation at ortho-position. Moreover, the effects offucoidans with 4--sulfation were superior to those of-LFUC with 2--sulfation. These data indicate that low Mw, 4--sulfation, and sulfation at meta-fucose contributed considerably to insulin resistance alleviation by SC-FUC, which could accelerate the development of SC-FUC as a potential food supplement to alleviate insulin resistance.