Protective effect of (-)clausenamide against Aβ-induced neurotoxicity in differentiated PC12 cells

The neurotoxicity of aggregated beta-amyloid (A beta) has been implicated as a critical cause in the pathogenesis of Alzheimer's disease (AD). In the present study, we investigated the effect of (-)clausenamide ((-)Clau), an aqueous extract of leaves of Clausena lassium (lour) skeel, on the neurotoxicity of A beta(25-35). The viability of differentiated PC12 cells was determined by MTT assay. Apoptosis was detected by flow cytometry. DCFH-DA was used for assessment of intracellular ROS generation, JC-1 and Rhodamine 123 for measurement of mitochondrial transmembrane potential (MMP). The intracellular calcium was determined with Fluo-3. The phosphorylation of p38 MAPK and the expression of Bcl-2, Bax, P53, Caspase 3 were examined by Western blot. The results showed that (-)Clau significantly elevated cell viability. Furthermore, (-)Clau arrested the apoptotic cascade by reversing overload of calcium, preventing ROS generation, moderated the dissipation of MMP and the misbalance of Bcl-2 and Bax, inhibiting the activation of p38 MAPK and the expression of P53 and cleaved Caspase 3. Our results suggested that (-)Clau may be a therapeutic agent for AD. (C) 2010 Elsevier Ireland Ltd. All rights reserved.