The pharmacokinetic characteristics and excretion studies of fucosterol from Sargasssum fusiforme in rats.

Fucosterol is the main phytosterol in brown algae with various pharmacological effects such as cholesterol-lowering, anticancer, hepatoprotection and neuroprotection. Little is known about the pharmacokinetics and excretion characteristics of fucosterol. In this study, a GC-MS method was developed and validated for the determination of fucosterol in rat plasma, urine and feces. The method effectively avoids the interference of Δ 5 -avenasterol, a cis-trans-isomer of fucosterol derived from feed, by using a TG-5 capillary column (a nonpolar column with 5% phenyl-methylpolysilicone as stationary phase material). The linearity ranges were fucosterol 0.300-18.0 μg/ml (R 2  = 0.9960) for plasma, 0.0500-2.50 μg/ml for the urine sample (R 2  = 0.9963) and 0.100-8.00 μg/mg (R 2  = 0.9923) for the feces sample. With good extraction recoveries and stability, this rapid and sensitive method was successfully applied to the pharmacokinetic and excretion studies of fucosterol in Sprague-Dawley rats. Fucosterol from Sargassum fusiforme had poor absorption and slow elimination with an absolute oral bioavailability of 0.74%, and was mainly eliminated through fecal excretion.