Evaluation of the neuroprotective potential of caffeic acid phenethyl ester in a cellular model of Parkinson's disease

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease, and oxidative stress and mitochondrial dysfunction play a major role in the pathogenesis of PD. Since conventional therapeutics are not sufficient for the treatment of PD, the development of new agents with anti-oxidant potential is crucial. Caffeic Acid Phenethyl Ester (CAPE), a biologically active flavonoid of propolis, possesses several biological properties such as immunomodulatory, anti-inflammatory and anti-oxidative. In the present study, we investigated the neuro-protective effects of CAPE against 6-hydroxydopamine (6-OHDA)-induced SH-SY5Y cells. The neuroprotective effects were detected by using cell viability, Annexin V, Hoechst staining, total caspase activity, cell cycle, as well as western blotting. Besides, the anti-oxidative activity was measured by the production of reactive oxygen species and mitochondrial function was determined by measurement of mitochondrial membrane potential (AIPm). We found that CAPE significantly increased cell viability and decreased apoptotic cell death (similar to 20%) after 150 mu M 6-OHDA exposure following 24 h. 1.25 mu M CAPE also prevented 6-OHDA-induced changes in condensed nuclear morphology. Furthermore, treatment with 1.25 mu M CAPE increased mitochondrial membrane potential in 6-OHDA-exposed cells. CAPE inhibited 6-OHDA-induced caspase activity (similar to 2 fold) and production of reactive oxygen species. In addition, 150 mu M 6-OHDA-induced down-regulation of Bcl-2 and Akt levels and up-regulation of Box and cleaved caspase-9/caspase-9 levels were partially restored by 1.25 mu M CAPE treatment. These results revealed a neuroprotective potential of CAPE against 6-OHDA-induced apoptosis in an in vitro PD model and may be a potential therapeutic candidate for the prevention of neurodegeneration in Parkinson's Disease.