Water soluble extract of P. linteus (WA) treatment reduces IgE secretion by B cells. (A) Dried mycelium of P. linteus was extracted sequentially with chloroform, methanol, water and boiling water and then the fractions were freeze-dried resulting in a powdered extract. The yield of each fraction was indicated in the bracket. (B) The effect of each extract of P. linteus, ME (methanol soluble fraction), WA (water soluble fraction), BW (boiling water soluble fraction) on the secretion of IgE from U266B1 cell line was measured by ELISA. (C) B220+ B cells were isolated from lymph nodes and spleen of BALB/c mice. These primary B cells were stimulated with LPS (10 μg/ml), IL-4 (5 ng/ml) and various concentrations of WA for 72 hrs and IgE level was measured by ELISA. Error bars indicated S.D. One (*), two (**) and three asterisk (***) indicates P < 0.05, P < 0.005, P < 0.001, respectively. Data are representative of three independent experiments.