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 H(2)O(2). 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 H(2)O(2)-induced neurotoxicity.