Biologically Active Components of Ganoderma lucidum and Its Antiprolifera-tion Action on the Human Peripheral Blood Lymphocytes

摘要

The traditional medicinal efficacies of Ganoderma lucidum are treatments of hepatopathy, nephritis, hypertension, hyperlipidemia, arthritis, neurasthenia, insomnia, bronchitis, asthma, gastric ulcer, arteriosclerosis and diabetes. Some of these efficacies, such as cytotoxicity on hepatoma cell, inhibition of platelet aggregation, antihypertension, hypocholesterolemic activity, inhibition of histamine release, and anti-HIV activity were scientifically proved to be true by virtue of isolation of the corresponding components. Although various components such as polysaccharides, proteins, minerals and sterols have been reported from this mushroom, triterpenoids are mainly responsible for the biological activities. More than 120 triterpenoids were reported in this medicinal fungus during the last three decades, there is a need to review most of the structures reported and their medicinal activities. The lanostane-type triterpenoids were divided into 10 groups according to their structural similarities and the known biological and medicinal activities were described in this article. There are few reports on the direct immuno-modulating effects of this mushroom on human peripheral blood immunocompetent cells. For elucidation of the im-munosuppressive mechanism of this mushroom, a methanolic extract of its basidiocarps was fractionated into six parts. When each of the six fractions was applied to the adherent and nonadherent cells of human peripheral blood mononuclear cells (PBMCs), proliferative arrest was observed and growth arrest was stronger in the non adherent cells than in the adherent cells. As the chloroform fraction of the fungus (GLE) arrested most strongly, it was further purified by silica gel column chromatography into seven subfractions. Among them, GLE1 fraction, the highest Rf value fraction, inhibited cell proliferation in a concentration-dependent manner. Anti proliferative activity of the GLE1 fraction was also observed in human allogeneic mixed lymphocyte culture(MLS). When secreted inter-leukin-2 (IL-2) of the culture supernatant of the MLC was measured by ELISA, the GLE1 fraction was found to inhibit IL-2 secretion, which was comparable to the effect of the GLE1 fraction blocked IL-2 secretion. The GLE1 fraction of G. lucidum therefore may have the potential to be developed into an immunomodulating agent.