Anti-Diabetic and Anti-Inflammatory Potential of the Edible Brown Alga Hizikia Fusiformis

Hizikia fusiformis, an edible brown alga, is found abundantly in Korea, Japan and China. We investigated the methanolic (MeOH) extract of H.fusiformis and its different fractions for anti-diabetic and anti-inflammatory activity. Of these, the CH₂Cl₂ and EtOAc fractions exhibited remarkable inhibitory activities against ONOO^- free radicals, PTP1B and α-glucosidase. Repeated column chromatography based on bioactivity-guided fractionation yielded fucosterol and fucoxanthin from the CH₂Cl₂ fraction and these two compounds inhibited tyrosine nitration in a dose-dependent manner. Furthermore, the CH₂Cl₂ fraction inhibited nitric oxide production and significantly suppressed expression of inducible nitric oxide synthase (iNOS) protein, whereas the EtOAc fraction effectively inhibited t-butyl hydroperoxide (t-BHP)-induced generation of reactive oxygen species in RAW 264.7 cells. The results demonstrate the potential anti-diabetic and anti-inflammatory activities of H.fusiformis. Practical Applications: Hizikia fusiformis has been used as a health food for hundreds of years in northwest Pacific areas. It is well known for its distinctive flavor and high content of calcium, vitamin A, inorganic salt, iodine and dietary fiber, all of which enable prevention of various diseases including diabetes, high blood pressure, colorectal cancer, constipation, thyroid cancer and beriberi. Modern research has suggested its potential for treatment of arteriosclerosis and osteoporosis. The findings of this study demonstrate the anti-diabetic and anti-inflammatory activities of the methanolic (MeOH) extracts of H.fusiformis and supports use of this seaweed as a functional food and a potential anti-diabetic.