Enhanced Oral Bioavailability and Tissue Distribution of a New Potential Anticancer Agent, Flammulina velutipes Sterols, through Liposomal Encapsulation

This study innovatively investigated the anticancer effect of Flammulina velutipes sterols (FVSs), the in vivo pharmacokinetics, and the tissue distribution of FVS-loaded liposomes. The FVS consisting of mainly 54.8% ergosterol and 27.9% 22,23-dihydroergosterol exhibited evident in vitro antiproliferative activity (liver HepG-2, IC50 = 9.3 μg mL–1; lung A549, IC50 = 20.4 μg mL–1). To improve the poor solubility of FVS, F. velutipes sterol liposome (FVSL) was originally prepared. The encapsulation efficiency of ergosterol was 71.3 ± 0.1% in FVSL, and the encapsulation efficiency of 22,23-dihydroergosterol was 69.0 ± 0.02% in FVSL. In comparison to its two free sterol counterparts, the relative bioavailability of ergosterol and 22,23-dihydroergosterol in FVSL was 162.9 and 244.2%, respectively. After oral administration in Kunming mice, the results of tissue distribution demonstrated that the liposomal FVS was distributed mostly in liver and spleen. The drug was eliminated rapidly within 4 h. These findings support the fact that FVS, a potential nutraceutical and an effective drug for the treatment of liver cancer, could be encapsulated in liposomes for improved solubility and bioavailability.