Inhibitory effects of ergosterol isolated from the edible mushroom Hypsizigus marmoreus on TPA‐induced inflammatory ear oedema and tumour promotion in mice

An antitumour‐promoting activity in two‐stage carcinogenesis, was found in the methanol and ethyl acetate extracts of the Japanese edible mushroom ‘Buna‐shimeji’, Hypsizigus marmoreus (Tricholomataceae). From the active fractions of the extracts, two sterols, ergosterol and ergosterol peroxide, were isolated. The isolates showed inhibitory activity against 12‐O‐tetradecanoylphorbol‐13‐acetate induced ear inflammation in mice, and ergosterol markedly inhibited tumour promotion in a two‐stage carcinogenesis experiment. These sterols may be useful in developing an effective method of cancer prevention.