Antiproliferative activity of extracts prepared from three species of Reishi on cultured human normal and tumor cell lines.

The present study investigated the growth of human fibrosarcoma (HT-1080) and fibroblast (SF-TY) cells in combination with water-soluble (WS) and high molecular component (HMC) fractions prepared from Reishi (R), Rokkaku-Reishi (2R) and Apple Rokkaku-Reishi (A2R). Each WS fraction exhibited dose-and time-dependent inhibition of the growth of the HT-1080 and SF-TY cells. The extracts exhibited marked antiproliferative activity against the HT-1080 cells. The HMC fractions inhibited cell growth dose-and time-dependently in the HT-1080 cells only, and not in the SF-TY cells, suggesting that HMC fractions selectively inhibit HT-1080 cells. Among the HMC fractions, A2R is a strong candidate for anti-tumor targeting since its fraction exhibited better inhibition than the R and 2R fractions. Furthermore, the volume of the A2R fraction was approximately five times greater than that of the others, and included four proteins (molecular mass 9, 13, 22 and 40 kDa) detected by SDS-PAGE. Three of these (13, 22 and 40 kDa) were confirmed to be glycosylated with the Periodic Acid-Schiff Stain kit. These results suggest that A2R may possess anti-tumor activity and, in particular, that the protein components of A2R may act to selectively inhibit the growth of HT-1080 cells.