P4-427 Ethanol extract of Alpinia oxyphylla fructus shows inhibition of tau protein phosphorylation in cell culture

Bushen Yizhi prescription (BSYZ) is a traditional Chinese compound prescription, which is commonly used in China for treating ShenXu and hypophrenia based on traditional Chinese medicine and Alzheimer's Disease according to modern Chinese medicine. Cnidium monnieri (L.) Cusson fruits (CM) is treated as the main herb of BSYZ, and its main active ingredient Osthole (OST) is considered as one of the major active ingredients of BSYZ. Even though OST plays an important role in the BSYZ its bioavailability is poor. In order to investigate whether the bioavailability of OST was influenced by BSYZ and CM extract, the comparative evaluations on pharmacokinetics of OST after oral administration of pure OST at different doses, CM and BSYZ extract were studied.30 rats were randomly assigned to five groups and orally administered with pure OST at different doses (15, 75 and 150 mg/kg), CM (15 mg/kg OST) and BSYZ (15 mg/kg OST) extract. At different predetermined time points after administration, the concentrations of OST in rat plasma were determined by using the HPLC–UV method, and main pharmacokinetic parameters were investigated.The results showed that the pharmacokinetic parameters of OST were significantly different (p<0.05) among the groups. The AUC0→t, AUC0→∞ and Cmax of OST were significantly increased after oral administration of BSYZ extract, followed by CM extract, in comparison to pure osthole at different doses.This present study indicated that the bioavailability of pure OST after oral administration was extremely low and it was dramatically enhanced because of the synergistic effect of the traditional Chinese Bushen Yizhi prescription.