INTRODUCTION

For many years, mushrooms have been consumed by man, not only as food but also as medicinal remedies. The use of the hot water extracts of fungi for treatment by the Chinese has a long history and the curative effects of mushrooms were recorded in many medicinal books, including the famous Shinnoh-Honsoh-Kyo (approx. 500 A.D), Honsoh-Kohhmoku (1552) and Ri Yong Ben Cao Vol. 3 (1620) [1, 2]. In recent years, some medicinal fungi were even used to treat cancer in the USSR, USA, Canada, China and Japan. Among them, the shiitake mushroom, Lentinus edodes, has been extensively studied for its valuable medicinal traits.

The most important anti-tumour component in Lentinus edodes is Lentinan, a ?-1,3-D glucan, which was extracted by Chihara and colleagues in 1969 [3, 4, 5]. Lentinan shows prominent anti-tumour activity against both allogenic tumors such as sarcoma 180, as well as synergic and autochthonous tumours, and it exerts its effect by stimulating the host s immune system. Many of the past studies [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 16] were carried out using the intravenous (i.v.) or intraperitoneal (i.p.) route of administration. Oral administration appeared to be a more attractive mode to introduce lentinan into the host s body since it is easier, more convenient, painless, requires no expertise and is...