Anti-obesity Effects of Wasabi Leaf Extract on Rats Fed a High-fat Diet are Related to Upregulation of mRNA Expression of β3-adrenergic Receptors in Interscapular Brown Adipose Tissue

Wasabi is a plant of Japanese origin belonging to the Brassicaceae family. Although the wasabi rhizome is a popular condiment in Japan, the leaf is typically discarded. For utilization of the wasabi leaf, we investigated its anti-obesity effect on Wistar rats fed a high-fat diet containing wasabi leaf extract (WLE) prepared with 50% ethanol. At the experimental endpoint, WLE had significantly decreased the body weight of rats and upregulated the mRNA expression of the β3-adrenergic receptor (Adrb3) in the interscapular brown adipose tissue (BAT). WLE may have promoted lipid absorption from the dietary fat, as the fecal lipid content was considerably lower in the WLE group. These results suggest that WLE suppressed obesity in rats fed a high-fat diet, which was related to the upregulation of Adrb3 mRNA expression in the interscapular BAT without increased fecal lipid excretion. Thus, wasabi leaves may be used as a functional food material for the suppression of obesity.