Inhibitory Activities of Essential Oil Obtained from Turmeric and Its Constituents against β-Secretase

Abstract

The need for a preventive agent against dementia led us to screen natural plant resources. Among the herbs and spices tested, turmeric, from rhizomes of Curcuma longa, showed high potency against β-secretase. The active principles were determined as α-turmerone, β-turmerone and ar-turmerone, with IC50 values of 39, 62 and 92 μM respectively. In this study, the efficiency of collecting the essential oil using steam distillation of the volatile substance was disclosed. The active principles were explored, and four sesquiterpenoids and five monoterpenoids were revealed as active principles against β-secretase. On the other hand, α-turmerone, β-turmerone and ar-turmerone were also investigated in a pharmacokinetic absorption experiment. After oral administration, these compounds were detected in an intact form in the brain and serum. These results suggest that consumption of turmeric constituents may prevent dementia.