Investigations into the cytotoxic effects of Australian indigenous mushrooms

The medical use of mushrooms has a very long tradition in Asia and is now becoming more accepted in the West. A variety of biological activities such as antimicrobial, anti-viral, anti-tumour, anti-allergic, immunomodulating, anti-inflammatory, anti-atherogenic, hypoglycaemic and hepatoprotective activities have been reported for extracts or isolated constituents from macrofungi [1]. The Australian environment is recognized as one of the most biologically diverse in the world. Indigenous Australian macrofungi are to a great extent unexplored with considerable numbers of un-described species of poorly known chemical, genetic and biological profiles [2]. Some species currently placed under northern hemisphere names are also expected to be novel once taxonomic revisions have been carried out. Ethanolic, cold and hot water extracts of Tricholoma sp., Hypholoma fasciculare, Agaricus bitorquis, Coprinus atramentarius and Coprinus comatus were screened for cytotoxic activity in normal mouse fibroblast cells (NIH 3T3), gastric adenocarcinoma cells (AGS), colorectal adenocarcinoma cells (HT-29) and MDA-MB-435S cells (ductal carcinoma) using a validated MTT assay with 25% DMSO as a positive control [3]. All of the extracts showed at least some cytotoxic activity. The hot water extracts of A. bitorquis and H. fasciculare showed the highest cytotoxicity against all cell lines with the IC₅₀ values of between 0.06–0.46mg/mL and 0.22–0.63mg/mL, respectively.

References: 1. Lindequist, U. et al. (2005) Evid. Based Complement. Alternat. Med. 2:285–299.

2. May, T.W. (2001) Australian Syst. Bot. 14: 329–356

3. Montoro, E. et al. (2005)J. Antimicrob. Chemother. 55: 500–505.