Absorption and pharmacokinetic study of two sulphated triterpenoid saponins in rat after oral and intravenous administration of saponin extracts of Pearsonothuria graeffei by HPLC-MS

Echinoside A (EA) and holothurin A (HA) are the major saponins found in sea cucumbers. Their pharmacokinetics were studied following intravenous and oral administration of saponin extracts in rats. The serum and liver of rat were pretreated by protein precipitation and performed on ENVI-18 SPE cartridges. The compounds were analyzed by using a high-performance liquid chromatography-mass spectrometry (HPLC-MS) method in the single ion monitoring (SIM) mode. The results demonstrated that serum EA concentration rapidly reduced in 5 min after intravenous administration. HA serum concentration reduced to its lowest level after 1 h. After oral administration, EA reached its peaks at 3 h and 7 h. The first peak of HA occurred at 3 h and reached a second peak at 9 h. In the liver, there were two peaks for EA at 2 h and 9 h, and only one peak for HA at 9 h.