Thioflavones as novel neuroprotective agents.

Oxidative stress is associated with the pathology of neurodegenerative diseases. Identification of small molecules capable of protecting against oxidative stress is therefore of significant importance. In this context, a library of 76 hydroxy flavones, methoxy flavones and their 4-thio analogues has been evaluated for neuroprotection against HO-induced oxidative stress. This revealed the synthetic 7,8-dihydroxy 4-thioflavones as neuroprotective compounds, with 14d and 18d showing highest neuroprotective effects at lower concentrations (0.3μM). Neuroprotection was found to be mediated via activation of the anti-apoptotic cell survival proteins of the ERK1/2 and PI3K/Akt pathways. Structure-activity relationship analysis revealed the B-ring phenyl group as essential for greater neuroprotection. Replacing the 4-CO moiety with a 4-CS moiety also generally enhanced neuroprotection.