Figure 5.

Proposed model of resveratrol mode of action during oxidative stress and DNA damage in C6 cells. (a) During oxidative stress and DNA damage resveratrol protective properties involves inhibition of caspase-3 activity. Resveratrol does this potently (yellow thick line) during oxidative stress, but during DNA damage it is less effective (blue thin line) at inhibiting caspase-3 activity. Additionally, resveratrol works on the phosphorylation state of tau at Serine residue 422 by regulating a kinase(s) or phosphatase(s). Resveratrol works effectively (blue thick line) during DNA damage by hyper-phosphorylating tau at Serine 422, which is directly next to the caspase-3 cleavage site, Asp 421. This could potentially block the caspase cleavage site from being available for caspase-3. Resveratrol is less effective (yellow thin line) at regulating tau phosphorylation at Ser⁴²² during oxidative stress; (b) Diagram of human tau showing the caspase-3 cleavage site (Asp⁴²¹) and phosphorylation site (Ser⁴²²). DMVD is a peptide sequence caspases recognize on their substrates, with caspase-mediated protein/peptide cleavage occurring between Asp⁴²¹ and Ser⁴²².