Chemical constituents isolated from Paeonia lactiflora roots and their neuroprotective activity against oxidative stress in vitro

The methanolic extract of Paeonia lactiflora roots significantly protected primary cultures of rat cortical cells exposed to oxidative stress induced by H₂O₂. Seven monoterpenes, paeonilactone-B (1), paeonilactone-C (2), paeoniflorigenone (3), benzoylpaeoniflorin (4), paeoniflorin (5), oxypaeoniflorin (6) and albiflorin (7), were isolated by bioactivity-guided fractionation and further separation using chromatographic techniques. Among them, compounds 2 and 4 significantly protected primary cultures of rat cortical cells against H₂O₂-induced neurotoxicity.