Japanese river alga Sujiaonori boasts anti-allergy, skincare benefits: Japanese study
The alga, which grows in Japan's Kochi prefecture, contains numerous bioactive compounds, such as omega-3 fatty acids, vitamins, and sulphated polysaccharides (ulvans).
Dietary intake of a Sujiaonori-based supplement has been said to "increase circulatory adiponectin, a salutary hormone that is reported to be associated with healthy longevity, and prevents a number of cardiovascular and metabolic disorders".
Researchers from the University of Kochi therefore aimed to determine the effects of Sujiaonori-derived ulvan (Tosalvan) on allergies, and those of a Sujiaonori-based supplement on skin health.
Tosalvan versus allergies
They used three different ulvan samples for allergy testing: those extracted from Sujiaonori growing in the Shimanto River in Kochi (Tosalvan 1), those from Sujianori grown at the Muroto Aonori Farm in Kochi (Tosalvan 2), and those from alga growing in the Yoshino River (Yoshino SP).
The samples were tested on mast cells, whose activation was used as a model of a skin allergy caused by Immunoglobulin E (IgE). All three were found to significantly reduce the cells’ release of the allergic inflammatory marker β-hexosaminidase, especially in comparison to the control group.
Tosalvan 1 and Tosalvan 2, in particular, inhibited this release by about 50 to 60%. Still, no significant difference was observed among the inhibitory effects of the three samples.
SBM for skin health
The researchers conducted a four-week clinical trial on 29 Japanese women who were divided into two groups: an intervention group whose participants were each supplemented with 3g of Sujiaonori algal biomaterial (SBM) powder twice daily, and a control group whose participants were each given 3g of a corn starch and spinach powder mixture twice daily.
Using trans-epidermal water (TEWL) loss as a skin health marker, they found that the women in the intervention group had significantly lower TEWL values after four weeks than when they’d first started the trial.
Their TEWL values were also markedly lower than those in the control group, and those in the intervention group below the age of 30 had lower TEWL values than those above 30. The same difference was not observed between the younger and older women in the control group.
The study stated that "bioactive materials from (the) river alga Sujiaonori (Tosalvan and an algal supplement) inhibited allergic reaction and improved skin health, respectively".
It concluded: "Future investigations are needed to confirm the beneficial effects of Sujiaonori biomaterials on human health."
Source: Journal of Functional Biomaterials
"Sujiaonori-Derived Algal Biomaterials Inhibit Allergic Reaction in Allergen-Sensitized RBL-2H3 Cell Line and Improve Skin Health in Humans"
Authors: Nlandu Roger Ngatu, et al.