Planta Med 2007; 73 - P_037
DOI: 10.1055/s-2007-986819

Investigations on the anti-leukemia and immunomodulating activities of Agaricus blazei extract

JJ Jiang 1, CF Kim 1, KP Fung 2, KN Leung 2, CBS Lau 1
  • 1School of Pharmacy
  • 2Department of Biochemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong

The medicinal mushroom Agaricus blazei (AB) is traditionally used as a remedy against various cancer, infection, and immune related diseases [1–3]. In present study, we investigated both the anti-leukemia and immunomodulatory effects of an ethanol-water extract of Agaricus blazei.

In MTT and tritiated thymidine incorporation assays, the AB extract showed statistical significant suppression on the growth of human acute promyelocytic leukemia NB-4 (IC50 values at 82.2±23.5µg/ml and 109.6±51.7µg/ml respectively) and the chronic myelogenous K-562 cells (IC50 values at 219.2±87.6µg/ml and 138.3±16.5µg/ml respectively) but has no growth-inhibitory effect on human normal liver cells WRL 68. In an attempt to clarify the underlying mechanisms, NB-4 cells were treated with AB extract and resulted in apoptosis characteristic DNA laddering using gel electrophoresis (20, 100 and 400µg/ml, 72h) and enrichment of nucleosome to maximum of 2.5-folds (250µg/ml, 48h) using cell death detection ELISA.

To investigate the immunomodulatory effect of AB extract, BALB/c mice were orally fed with water (as control) or extract (100 or 500mg/kg/day, n=7) for 28 days. Splenic lymphocytes isolated from these mice on day-14 and day-28 were incubated with mitogens LPS or Con A for 72h. Our results indicated that both AB extract treated groups significantly lowered the ex-vivo mitogen-stimulated lymphocyte proliferation in tritiated thymidine incorporation assay, with p<0.0001 in all cases using two-way ANOVA.

In conclusion, AB extract inhibited the growth of leukemia cells, at least in part, by induction of apoptosis. This is also the first report of AB extract in suppressing ex-vivo mitogen-stimulated lymphocyte proliferation.

Acknowledgements: This study is supported by HKSAR RGC Competitive Earmarked Research Grant CUHK4531/05M.

References: [1] Bernardshaw, S. et al. (2005) Scand. J. Immunol. 62(4):393–8. [2] Higaki, M. et al. (1997) Nippon Yakurigaku Zasshi 110 Suppl 1: 98–103. [3] Mizuno, T. (2002) Int. J. Med. Mushroom 4: 299–312.