Tanshinone IIA attenuates Aβ-induced neurotoxicity by down-regulating COX-2 expression and PGE2 synthesis via inactivation of NF-κB pathway in SH-SY5Y cells.

Amyloid-β (Aβ)-induced neurotoxicity is a major pathological mechanism of Alzheimer's disease (AD). Tanshinone IIA (Tan IIA), extracted from traditional Chinese herb , possesses anti-oxidant and anti-inflammatory actions, as well as neuroprotective effects. The present study aims to explore the possible mechanism by which Tan IIA attenuated Aβ-induced neurotoxicity. Exposure of SH-SY5Y cells to different concentrations of Aβ led to neurotoxicity by reducing cell viability, inducing cell apoptosis and increasing neuroinflammation in a dose-dependent manner. Moreover, Aβ treatment promoted cyclooxygenase-2 (COX-2) expression and Prostaglandin E2 (PGE2) secretion, and activated nuclear transcription factor kappa (NF-κB) pathway in SH-SY5Y cells. However, pretreatment of SH-SY5Y cells with Tan IIA prior to Aβ prevented these Aβ-induced cellular events noticeably. These data suggested that Tan IIA exerted its neuroprotective action by alleviating Aβ-induced increase in COX-2 expression and PGE2 secretion via inactivation of NF-κB pathway.