Influence of Selected Natural Products on Neutral Endopeptidase Activity and beta-Amyloid Production in SK-N-SH Cells

摘要

Abstract Neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE) belong to the major Abeta-degrading enzymes. We currently demonstrate that apigenin, luteolin, and cur-cumin are able to enhance the activity of NEP and ACE. In this research, we examined the influence of these substances on the amount of endogenously produced and secreted Abeta of neuroblastoma cells. We found that treatment of the cells for 72 h with apigenin, luteolin, and curcumin decreases the endogenous Abeta1-42 level of SK-N-SH cells significantly, which indicates that the upregulation of both NEP and ACE activity leads to a decrease of A beta in the medium. Furthermore, we showed that all of these substances are able to increase the intracellular cAMP level, which verifies our previous supposition that the enhancement of cellular NEP activity is correlated with an increase of cAMP level.