Abstract
We have examined the antitumor activity of extracts obtained from the fruiting body of Agaricus blazei Murill on Meth-A tumor (fibrosarcoma) cell growth using the double- or single-grafted mouse tumor system. Intra-tumoral administration of water-insoluble (fraction 1), water-ethanol-insoluble (fraction 2), the ammonium oxalate-soluble (fraction 3) and -insoluble fractions (fraction 4) resulted in an inhibition of tumor growth, in which fraction 3 contained the highest tumoricidal activity. However, oral administration of solid feed containing the respective fractions over prolonged periods (4-18 days), prior to tumor cell inoculation, resulted in no inhibition of tumor cell growth in the single-grafted tumor system. The fraction 3, after acid-treatment which resulted in no marked loss of tumoricidal acitivity as assessed by intra-tumor injection, also induced a significant inhibition of tumor growth via daily repetitive oral administrations 4 days prior to tumor inoculation, but not when given at the same time or after the tumor inoculation. Animals were totally unaffected at a single intravenous injection of this fraction. Simple acid-treatment of the fruiting bodies may contribute to increased absorption in the digestive organs, leading to increased transport to the tumor sites via the blood stream and tumorcytocidal activity in situ.
