Preparation, chemical characterization and determination of crocetin's pharmacokinetics after oral and intravenous administration of saffron (Crocus sativus L.) aqueous extract to C57/BL6J mice

Objectives To prepare a lyophilized saffron aqueous extract (SFE) and determine its chemical profile and serum and tissue pharmacokinetics after intravenous and oral administration to C57/Bl6J mice. Methods Lyophilized SFE was prepared, characterized using semi-preparative HPLC and NMR analysis, and stability studies at room temperature, and was quantified for crocin content with an HPLC-PDA method. After intravenous and oral administration of SFE (60 mg/kg, reconstituted with water for injection) to C57/Bl6J mice, crocetin (derived from in vivo crocin hydrolysis) serum and tissue levels (unconjugated and total) were measured with an HPLC-PDA method and subjected to compartmental and non-compartmental PK analysis. Key findings Saffron aqueous extract was rich in all-trans-crocin (27.8 +/- 0.1% w/w) and stable for more than 15 months. One-compartment PK model described crocetin's (unconjugated) kinetics after intravenous administration of SFE, while a first-order kinetic parameter described the rate of crocetin biotransformation to crocetin metabolite (conjugated). Alpha omicron ne-compartment PK model with first-order absorption described crocetin and crocetin's metabolite kinetics after SFE oral administration. Relative oral bioavailability was calculated at 1.17 for total crocetin. Tissue NCA PK analysis revealed extensive crocetin distribution to liver and kidneys. Conclusions SFE is a stable lyophilized extract rich in all-trans-crocin. The PK study allowed the estimation of basic PK parameters and the bioavailability of SFE's main bioactive component, crocetin, after peros administration.