Proteinous pancreatic lipase inhibitor is responsible for the antiobesity effect of young barley (Hordeum vulgare L.) leaf extract.

Young barley leaves (Hordeum vulgare L.) have various health effects and are employed as an ingredient in the production of health-promoting foods. Promoting antiobesity is one such health effect; however, the mechanism and bioactive compounds are unclear. In this research, young barley leaf extract (YB) was demonstrated to possess pancreatic lipase inhibitory activity. The addition of YB to a high-fat diet in mice increased fecal lipid content, indicating reduced absorption of lipids as the mechanism underlying antiobesity effect. The investigation of bioactive compounds in YB resulted in the identification of fructose-bisphosphate aldolase as a proteinous lipase inhibitor. Maximum inhibition of the protein was 45%, but inhibition was displayed at a concentration as low as 16 ng/mL, which is a characteristic inhibition compared with other reported proteinous lipase inhibitors.