Oral Administration of Edible Seaweed Undaria Pinnatifida (Wakame) Modifies Glucose and Lipid Metabolism in Rats: A DNA Microarray Analysis

Scope: Wakame is an edible seaweed that is a common constituent in the Japanese diet. Previous studies showed that wakame consumption is associated with the prevention of metabolic syndrome, but the molecular mechanisms underlying the protective effects are poorly understood. Methods and results: To determine if the expression of hepatic genes is affected by ingestion of the brown seaweed Undaria pinnatifida (wakame), rats were fed a diet containing 0, 0.1, or 1.0 g per 100 g dried wakame powder for 28 days. Administration of 1% wakame significantly decreased serum total cholesterol levels. Hepatic gene expression was investigated using DNA microarray analysis, and the results showed that wakame suppresses the lipogenic pathway by downregulating SREBF-1. Moreover, bile acid biosynthesis and gluconeogenesis were promoted by upregulation of the PPAR signaling pathway, which leads to a reduction in the accumulation of cholesterol and promotion of beta-oxidation. Conclusions: These results suggest that wakame ingestion affects glucose and lipid metabolism by altering the expression of SREBF-1 and PPAR signal-related genes.