Neuroprotection by herbal formula FBD and its active compounds

FBD, a Chinese herbal formula, composed of Fu Ling [the sclerotium of the fungus of Poria cocos (Schw.) Wolf (Polyporaceae)], Bai Zhu [the rhizome of Atractylodes macrocephala Koidz.(Compositae)], and Danggui [the root of Angelica sinensis (Oliv.) Diels (Umbelliferae)], has been found beneficial in treating brain ischemia-reperfusion (I/R). In this work, oral pretreatment with supercritical CO2 extract (FBD-CO2, 37.5 mg/kg) twice daily for 3.5 days, significantly attenuated brain infarction (p < 0.05), blocked neuron specific enolase (NSE) efflux (p < 0.05) in mice subjected to repetitive 10 min of common carotid artery occlusion following 24 h reperfusion, whether coupled with aqueous extract (FBD-H2O, 150 mg/kg) or not. Except atractylenolide I and pachymic acid, atractylenolide II, III, levistolid A, and ferulic acid isolated from FBD-CO2 alone protected neuron-like PC12 cells obviously and concentration-dependently against I/R-like insults (p < 0.05 similar to 0.01) induced by sodium dithionite (10 mM), monosodium glutamate (2 mM), KCl (0.2 M), or hydrogen peroxide (0.2 mM) at 1-100 mu M. Even though at sub-active concentrations (< 1 mu M), the combination of the six components contained in FBD-CO2 (10 mu g/mL), protected markedly PC12 cells (p < 0.01), in a synergistic fashion. Moreover, intraperitoneal treatment with dual doses of 37.5 mg/kg FBD-CO2 and 1.2 mg/kg combination reduced both infarct size (p < 0.01 and p > 0.05, respectively) and NSE efflux (p < 0.05 and p > 0.05, respectively). Therefore, neuroprotection by FBD on I/R induced neuronal injury originated partially from the synergies of its compounds atractylenolide II, atractylenolide III, levistolid A and ferulic acid.