Journal of Ethnopharmacology 138 (2011) 192–200 Contents lists available at SciVerse ScienceDirect Journal of Ethnopharmacology jo ur nal homep age : www.elsevier.com/locate/jethpharm Evaluation of the sub-acute toxicity of the sclerotium of Lignosus rhinocerus (Cooke), the Tiger Milk mushroom Sook Shien Lee a , Nget Hong Tan a,∗ , Shin Yee Fung a , Jayalakshmi Pailoor b , Si Mui Sim c a CENAR and Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia b Department of Pathology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia c Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia a r t i c l e i n f o Article history: Received 2 June 2011 Received in revised form 15 July 2011 Accepted 4 September 2011 Available online 10 September 2011 Keywords: Lignosus rhinocerus Sub-acute toxicity Sclerotium a b s t r a c t Ethnopharmacological relevance: Lignosus rhinocerus (known locally as ‘Tiger Milk mushroom’) is the most important medicinal mushroom used by the indigenous communities of Malaysia to treat fever, cough, asthma, cancer, food poisoning and as a general tonic. The sclerotium of the mushroom is the part with medicinal value. Lignosus rhinocerus was hitherto unexploited commercially because of limited supply. Recently, the mushroom was successfully cultivated. Materials and methods: Sprague Dawley rats (5 rats/group/sex) were fed orally with 250, 500 and 1000 mg/kg TM02, 1000 mg/kg TM03 as well as 1000 mg/kg wild type Lignosus rhinocerus sclerotial powder. Sclerotial powder was orally administered once daily and consecutively for 28 days. Body weight of each animal was measured and any gross behavioral change was observed daily. Hemato- logical and clinical biochemical parameters as well as histopathological analysis were carried out on 29th day. Results: The results showed that oral administration of the sclerotial powder at daily dose of up to 1000 mg/kg had no adverse effect on the growth rate, hematological and clinical biochemical param- eters (including renal and liver function parameters). Histological studies showed that the treatments did not induce any pathological changes in the liver, kidney, heart, spleen and lung of the animals. Conclusion: In conclusion, our results show that there was no treatment-related sub-acute toxicity in rats following 28-days oral administration of 250, 500 and 1000 mg/kg TM02, 1000 mg/kg TM03 as well as 1000 mg/kg wild type Lignosus rhinocerus sclerotial powder. As the highest tested dose of 1000 mg/kg was not associated with any toxicity concern, the NOAEL dose is higher than 1000 mg/kg. © 2011 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Lignosus rhinocerus (Tiger Milk mushroom), belongs to the Poly- poraceae family, is an important medicinal mushroom in Southeast Asia and China. In Malaysia, it is also known as ‘cendawan susu rimau’ and is the most popular medicinal mushroom used by the indigenous communities of Peninsular Malaysia (Lee et al., 2009). It was used to treat a variety of diseases, including fever, cough, asthma, cancer, food poisoning and as a general tonic (Lee et al., 2009). Phylogenetic analysis indicated that the mushroom is closely related to Ganoderma lucidum and Trametes versicolor, the two most popular medicinal mushrooms used in Asia (Tan et al., 2010). The sclerotium of Lignosus rhinocerus is the part with medici- nal value. The existence of this mushroom in the jungle is always ∗ Corresponding author. Tel.: +60 379674912; fax: +60 379674957. E-mail address: tanngethong@yahoo.com.sg (N.H. Tan). solitary and this makes collection of the mushroom’s sclerotia a difficult task. As a result, the sclerotium is costly and its supply is limited. Recently, Tan (2009) reported a successful cultivation of the mushroom in agar, solid and spawn medium with good yield, thus overcoming the supply problem. The antiproliferative effects of the sclerotium of Lignosus rhinocerus have been investigated. Lai et al. (2008) demonstrated that sclerotial polysaccharides from Polyporus rhinocerus (synonym of Lignosus rhinocerus) exhibited antiproliferative effects on several kinds of leukemic cell lines. Wong et al. (2009) reported that the hot water extract of Polyporus rhinocerus exhibited immunomod- ulatory effect by stimulating human innate immune cells. Our preliminary studies also demonstrated that the cold water extract of Lignosus rhinocerus sclerotium exhibited direct cytotoxicity on human breast carcinoma (MCF-7) and human lung carcinoma (A549) cell lines (Lee et al., 2010). Furthermore, Gao et al. (2009) showed that the nondigestible carbohydrates might function as novel prebiotics. 0378-8741/$ – see front matter © 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jep.2011.09.004