The aim of this study was to optimize the extraction parameters of Fomes officinalis Ames polysaccharides (FOAPs) and evaluate their antitumor activity. FOAPs were extracted using the hot water extraction, acid extraction and alkali extraction methods, respectively. Alcohol precipitation and acetone washes were conducted to separate and purify the FOAPs. The FOAP content was determined using the phenol-sulfuric acid method. The effects of raw material particle size, extraction time and material-liquid ratio on the yield of FOAPs were investigated, and the effects of FOAPs on the immune function of S180 tumor-bearing mice and their antitumor activity were evaluated. The yield of FOAPs obtained with the hot water extraction method was higher compared with the yields of the other methods. The optimum extraction conditions were as follows: a raw material particle size of 24 mesh; an extraction time of 2.5 h; and a material-liquid ratio of 1 g:12 ml. Under these conditions, the yield of FOAPs was 1.13%. FOAPs significantly inhibited tumor growth and enhanced the immune function in S180 tumor-bearing mice. FOAPs extracted using the hot water extraction method have antitumor activity.
Keywords: Fomes officinalis Ames; S180 tumor-bearing mice; extraction; immune function; polysaccharide.