Characterization of bioactive components from arsenic-lower Jeju Hizikia fusiforme

Abstract

Traditional medical application becomes potential supplement which is widely used as therapies for avoiding diseases in oriental countries [1]. Ocean is regarded as a life blood of all living creature with more than 70% of water mass surrounded on earth [2]. There are predicts 2.2 million eukaryotic species living under the water [3], hence marine product is a promising resource for medical application [4]. Seaweed, also named algae, refers to three types, Rhodophyta (red seaweed), Phaeophyta (brown seaweed), and Chlorophyta (green seaweed) [5]. Hizikia fusiforme, Hijiki, is a well-known brown seaweed that has been consumed as a marine resource for hundred years in Korea, Japan, and China [6, 7]. Hijiki is used as functional food because of its widely range of bioactivities [8, 9]. It is rich in nutrients including polysaccharides and mineral elements, and shows beneficial effects such as anticancer, immunomodulating activities, and anti-mutagenic effects [10-12]. Hijiki contains higher amounts of mineral elements than other foods [13]. At certain doses, most of mineral elements are regarded as nutrition, but some metals are human toxicants such as inorganic arsenic (iAs). iAs tend to be more toxic than organic arsenic, and the concentrations of iAs in Hijiki are as high as hundreds of ppm. It is indicated that the As concentration is greatly exceeds the limit stated under the provisional tolerable weekly intake, as advised by the World Health Organization (WHO) [14]. Chronic and acute exposure to arsenic leads to cancer, neurological disorders, liver disease, renal disease, and other health disorders [15, 16]. Acid-wash and hot water cooking are the most widely used methods to iAs removal [17-20], and the level of iAS intake allows the limits recommended by the WHO. In this work, one percentage of citric acid- and hot water processing was performed to remove AS in Hijiki. The As-lower Hijiki was used for separated and isolated different bioactive fractions depend on their polarity. There are three active fractions: polysaccharides, saringosterol acetate, and fucoxanthin, which were isolated from water, hexane, and chloroform extraction, respectively. In water extraction, polysaccharides are the high amounts and bioactivities fractions. In polysaccharides, alginic acid and fucoidan are the two major active compounds. Alginic acid is a protonized water-insoluble polysaccharide, and comprises a family of unbranched binary copolymers of (1→4) linked β-D-mannuronic acid and α-L-guluronic acid [21]. Fucoidan is a sulfate-rich polysaccharide [22], which have been investigated its biological properties such as antioxidant, antiviral, anticancer, anti-inflammatory, anti-coagulant, anti-angiogenic, and anti-adhesive effects [23-27]. In seaweeds, the molecular weight, sulfate content, and monosaccharide composition are the three main factors linked to the biological activity of fucoidan [28]. Moreover, the structural characteristics of fucoidan differ depending on the extract method, seaweed species, harvest season, geographic area, and algal maturity [24, 29-31]. Therefore, in the presence work, the bioactivities of polysaccharides from AS-lower Hijiki were evaluated. In hexane extraction, saringosterol acetate was isolated by using centrifugal partition chromatography, and the anticancer and anti-obesity effects of saringosterol acetate were evaluated. In chloroform extraction, fucoxanthin-riched fraction was isolated and evaluated its anti-inflammatory effect against FD-induced inflammatory responses. Taken together, the aim of this study is to explore and discover the various properties of compounds of AS-lower Hijiki from different collected locations.