Compressional-puffing pretreatment enhances neuroprotective effects of fucoidans from the brown seaweed sargassum hemiphyllum on 6-hydroxydopamine-induced apoptosis in SH-SY5Y cells

Abstract

In this study, a compressional-puffing process (CPP) was used to pretreat Sargassum hemiphyllum (SH) and then fucoidan was extracted from SH by hot water. Three fucoidan extracts, namely SH1 (puffing at 0 kg/cm2); SH2 (puffing at 1.7 kg/cm2); and SH3 (puffing at 10.0 kg/cm2) were obtained, and their compositions and biological activities were evaluated. The results indicate that CPP increased the extraction yield, total sugar content, and molar ratios of sulfate/fucose of fucoidan and decreased molecular weight and impurities of fucoidan. The SH1–SH3 extracts exhibited characteristics of fucoidan as demonstrated by the analyses of composition, FTIR spectroscopy, NMR spectroscopy, and molecular weight. All SH1–SH3 extracts showed antioxidant activities. The SH1–SH3 extracts protected SH-SY5Y cells from 6-hydroxydopamine (6-OHDA)-induced apoptosis as illustrated by cell cycle distribution, cytochrome c release, activation of caspase-8, -9, and -3, and DNA fragmentation analyses. Additional experiments revealed that phosphorylation of Akt is involved in the opposing effects of SH1–SH3 on 6-OHDA-induced neurotoxicity. SH3 exhibited a relatively high extraction yield, the lowest levels of impurities, and was the most effective at reversing the 6-OHDA-induced neurotoxicity of SH-SY5Y cells among SH1–SH3, which taken together indicate that it may have potential as a candidate therapeutic agent for the preventive therapy of neurodegenerative diseases.