Oleuropein Aglycone (3,4-DHPEA-EA) is a polyphenol and the aglycone form of oleuropein , formed by enzymatic, acidic or acetylated hydrolysis of oleuropein. Dietary intake of oleuropein Aglycone (50 mg/kg diet) increases the number of neuronal autophagic vesicles, reverses cognitive deficits in the TgCRND8 transgenic mouse model of Alzheimer's disease, and reduces the levels of histone deacetylase 2 (HDAC2) in the cortex and hippocampus. Oleuropein Aglycone increases urinary norepinephrine, interscapular brown adipose tissue epinephrine, and UCP1 protein levels, and reduced plasma leptin levels and total abdominal adipose tissue weight in a rat model of high-fat diet-induced obesity. Oleuropein Aglycone also reduced lung neutrophil infiltration, lipid peroxidation, and IL-1β levels in a mouse model of carrageenan-induced pleurisy.