EVALUATION OF CYTOTOXICITY AND GENOTOXICITY OF SELECTED MEDICINAL MUSHROOM USED IN TRADITIONAL MEDICINE N. Nur Shahirah* 1,2 , M.Y. Farida Zuraina 1 , R. Nor Fadilah 2 , C.F. Suziana Zaila 1,2 , L. Florinsiah 1,2 , M.N. Norfazlina 1,2 and L. Lek Mun 2 . 1 Faculty of Applied Sciences, Universiti Teknologi MARA,40450, Shah Alam, Selangor. 2 Toxicology Laboratory, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan, Malaysia. ABSTRACT The Agaricus Blazei, Grifola Frondosa and Hericium erinaceus are popular medicinal mushroom. They has been widely consumed in many countries, including Malaysia, because of its therapeutic properties and commonly used in traditional medicine. This study was carried out to determine the in vitro toxicity of these medicinal mushrooms that were cultivated in Malaysia and their possible risk to human health. The cytotoxic and genotoxic activity were evaluated against Chinese hamster fibroblast cell line (V79-4) using MTT assay and alkaline comet assay. Five different concentrations of the mushroom extracts (2mg/ml, 1mg/ml, 0.5mg/ml, 0.25mg/ml and 0.125mg/ml) in 70% methanol and aqueous solvent were used. The cytotoxicity was determined following 24 hours treatment. Our result demonstrated that all extracts show decreased in cell viability at the maximum concentration 2mg/ml. On the other hand, none of the extracts caused DNA damage to the V79-4 cells at 2mg/ml following 24 hour incubation, as compared to the positive control, menadione (tail moment-13.135±2.273). In conclusion, several mushroom extracts showed weak cytotoxic effect but did not cause DNA damage against Chinese hamster fibroblast cell line (V79-4), suggesting that these mushrooms are safe to consume. INTRODUCTION Alongside the mushrooms’ long history as a food source is an equally long history of beliefs about their curative abilities in traditional medicine systems. Although there are limited direct human intervention trials, there is a rapidly growing volume of in vitro and in vivo animal trials describing a range of possible health benefits. Lately, crop development in Malaysia attempt to produce its own organic medicinal fungus such as Agaricus blazei, Grifola frondosa and Hericium erinaceus to develop a wealth of expertise in the use of medicinal mushrooms for conjunctive therapy and also as a wellness product. Previous study have reported that some of mushroom extracts from geographic locations varied in genotoxic activity, some being more efficient while others had no protective effect (Elgorashi,2003). It is necessary to obtain epidemiological and experimental data on the beneficial effects of the extracts of the species studied. Assessment of the potential genotoxicity of traditional medicines is indeed an important issue as damage to the genetic material may lead to critical mutations and therefore increase the risk of cancer and other diseases. In vitro cytotoxicity tests such as MTT assay are useful to measure viability of cell and are considered as the initial step in toxicity study. MTT is a yellow water-soluble tetrazolium salt. Metabolically active cells are able to convert the dye to water-insoluble dark blue formazan by reductive cleavage of the tetrazolium ring. On the other hand, the comet assay or the single cell gel electrophoresis (SCGE) introduced by Ostling and Johanson in 1984 has been widely used for the assessment of the genotoxicity (Ostling and Johanson,1984). The alkaline version of the comet assay developed by Singh et al. in 1988 detects DNA single strand breaks and alkali-labile sites. It has been recognized as