Pharmacokinetic and tissue distribution profile of curculigoside after oral and intravenously injection administration in rats by liquid chromatography-mass spectrometry.

Curculigoside has an extensive pharmacological activity, including estrogen-like, improving sexual behavior, antiosteoporotic, antioxidant, immunomodulatory and neuroprotective effects. However, few investigations have been conducted about the pharmacokinetics and tissue distribution of curculigoside to better understand its behavior and action mechanism in vivo. Thus, a sensitive and reliable liquid chromatography with mass spectrometry (HPLC-MS) method was established and validated for the quantification of curculigoside in rat plasma and tissue samples. Biological samples were processed with methanol precipitation, and naringin was used as the internal standard. Chromatographic separation was performed on an Agilent XDB-C18 chromatography column (3.0mm×50mm, 1.8µm) with a mobile phase consisting of acetonitrile and 0.1% formic acid. Quantification was performed by selected ion monitoring with m/z 511.1 [M+HCO2](-) for curculigoside and m/z 579.1 [M-H](-) for the internal standard. The validated method was successfully applied to the pharmacokinetic and tissue distribution study of curculigoside in rats. Non-compartmental pharmacokinetic parameters indicated that curculigoside had rapid distribution, extensive tissue uptake, and poor absorption into systemic circulation. The values of absolute bioavailability were 0.38%, 0.22% and 0.27% for oral doses of 100, 200 and 400mg/kg, respectively. The results of the tissue distribution study suggested that curculigoside was distributed into the heart, lung, spleen, intestine, stomach, kidney, thymus, liver, brain, testis, and bone marrow after oral administration of 150mg/kg. In conclusion, the present study may provide a material basis for study of the pharmacological action of curculigoside, and meaningful insights into further study on clinical application.