Pharmacokinetics, tissue distribution and excretion study of a furostanol glycoside-based standardized fenugreek seed extract in rats

The furostanol glycoside isolated from the seed of fenugreek (SFSE-G) has an array of pharmacological activities. To date, no validated high-performance liquid chromatography (HPLC) method has been reported for quantification of SFSE-G in biological samples. Hence, the aim of the present study was to study the pharmacokinetics, tissue distribution and excretion profiles of SFSE-G after oral administration in rats. A rapid, sensitive, selective, robust and reproducible HPLC method has been developed for determination of SFSE-G in the rat biological samples. The chromatographic separation was accomplished on a reversed-phase C18 column using formic acid and acetonitrile (80:20) as mobile phase at a flow rate of 1.0 mL/min and 274 nm as a detection wavelength. The assay was linear for SFSE-G with the correlation coefficients (R²) >0.996. The analytes were stable during samples storage and handling, and no matrix effects were observed. After oral dosing of SFSE-G at a dose of 200 mg/kg, the elimination half-life was app. 40.10 h. It showed relatively slowly distribution and eliminated in urine and feces after 24 h, and could be detected until 108 h post-dosing. Following oral single dose (200 mg/kg), SFSE-G was detected in lung and brain which indicated that it could cross the blood–brain barrier. It is a major route of elimination is excretion through urine and feces. In conclusion, oral administration of SFSE-G showed slow distribution to tissues, such as lung and brain, but showed fast renal elimination.