A mechanism of low molecular weight fucoidans degraded by enzymatic and acidic hydrolysis for the prevention of UVB damage

Fucoidans have been long used as a food supplement due to their diverse pharmacological effects on human health. Low molecular weight fucoidan (LF) is a common form of fucoidans that has been shown to have enhanced biological activity. In the present study, fucoidans were extracted from the brown alga Sargassum hemiphyllum and enzyme-hydrolyzed into low and high molecular weight fucoidans (HF). The skin protective effects of LF, HF, and other fucoidans derivatives against ultraviolet B (UVB) damage were determined by measuring the expression levels of matrix metalloproteinase genes encoding collagenases (MMP-1, MMP-2, MMP-8, MMP-9, MMP-13), transforming growth factor beta receptor II (TGF beta RII), and type I procollagen. The results show that LF protects against UVB damage to the skin by inhibiting UVB-induced transcription factor activator protein-1 (AP-1)-stimulated transcription of MMP genes encoding collagenases (MMP-1, MMP-8, and MMP-13) and increasing TGF beta RII mRNA levels to prevent the loss of TGF beta RII that occurs during UVB-induced collagen degradation. Moreover, this study reveals that the biological properties of fucoidans are highly dependent on the fucose content, sulfate content, and molecular weight.