Antitumor Activity Exhibited by Orally Administered Extract from Fruit Body of Grifola frondosa (Maitake)
Hishida, I, Nanba, H, Kuroda, H
Laboratory of Microbiology, Kobe Women’s College of Pharmacy, Japan
The acid-insoluble, alkali-soluble, hot water-extractable polymer (a polysaccharide containing approximately 30% of protein; D-fraction) obtained from the fruit bodies of Grifola frondosa ( maitake ) exhibited antitumor activities against allogenic and syngeneic tumors on oral administration to mice. Winn assay conducted to examine the tumor growth-suppressing effect revealed a complete inhibition of the tumor by the oral administration of D-fraction. This fact indicates that stimulation of the immune response system triggered by the tumor-bearing state is activated by D-fraction. Consequently, the activity of D-fraction on cells associated with immune response was examined. The cytolytic activity and interleukin-1 productivity of macrophages or T cells which exhibit antigen-specific cytotoxicity were enhanced. D-fraction was found to potentiate the delayed-type hypersensitivity response which is associated with tumor growth suspension.