Acute Toxicity Study and the In Vitro Cytotoxicity of a Black Lingzhi Medicinal Mushroom, Amauroderma rugosum (Agaricomycetes), from Malaysia

Amauroderma rugosum is a wild medicinal mushroom also known as budak cendawan sawan. Members of the indigenous Malaysian Temuan community wear the fresh stipes as a necklace to prevent epileptic seizure and unremitting crying by babies. In our previous studies, A. rugosum exhibited significant antioxidant and anti-inflammatory activities. The aim of this study was to determine the toxicity (in the event that a stipe is accidentally bitten) and cytotoxicity of this mushroom on Sprague-Dawley rats and selected cell lines. A. rugosum was orally administered to test chemicals according to Organisation for Economic and Co-operation and Development guidelines (TG 425, adopted October 3, 2008). Blood samples were hematologically and biochemically analyzed and multiple tissue sections from each organ were examined using light microscopy. Cytotoxicity of various A. rugosum extracts was also determined against MCF-7 and A-549 cell lines. Our results showed that oral administration of a single dose of mycelial powder (2000 mg/kg) had no adverse effect on the growth rate or hematological and clinical biochemical parameters. Histological studies showed that the treatments did not induce any pathological changes in the organs of the tested animals. All the treated rats survived beyond the 14-day observation period. Methanol and cold and hot water extracts of the freeze-dried mycelial culture of A. rugosum exhibited no or little cytotoxic effect against the MCF-7 and A-549 cell lines.