Sacran: Novel sulfated polysaccharide as anti-allergic skincare biomaterial for atopic dermatitis

Abstract

Atopic dermatitis (AD) is a skin disease characterized by inflammation, pruritus, and chronic or relapsing eczematous lesions. AD negatively affects quality of life for both patients with AD and their caregivers. We conducted a review of the literature on the beneficial effects of sacran on allergic skin diseases using published biochemical, experimental, and clinical reports. Sacran is a marine alga-derived glycosaminoglycan-like sulfated polysaccharide; it is extracted from the Japanese indigenous cyanobacterium Aphanothece sacrum, which is mass-aquacultured in rivers with a high ionic concentration and possesses plenty of a jelly-like extracellular matrix with high water content (97.5-98.3%). Sacran is a heteropolysaccharide composed of various sugar residues (galactose, glucose, mannose, xylose, rhamnose, fucose, galacturonic acid, and glucuronic acid) and contains traces of alanine, galactosamine, uronic acids (these uronic acids have yet to be determined chemically), and muramic acid; 11% of the monosaccharides contain a sulfate group, and 22% of them contain a carboxyl group. Our previous studies have shown that topical sacran markedly reduced transepidermal water loss (TEWL) in dry skin human subjects and displayed similar anti-allergic effects than hydrocortisone and tacrolimus in animal experiments. Moreover, our recent clinical studies showed that topical sacran significantly decreased the severity of AD skin lesions, itch, and sleep disorder in AD patients within 4 weeks of topical treatment. Taken together, findings from these studies suggest that topical sacran may serve as an alternative adjuvant and therapeutic anti-allergic agent.