The anti-tumor effect of Ganoderma lucidum is mediated by cytokines released from activated macrophages and T lymphocytes.
The present study was to ascertain the immunomodulating and anti-tumor effects of Ganoderma (G.) lucidum. Polysaccharides (PS) from fresh fruiting bodies of G. lucidum (PS-G) were isolated and used to potentiate cytokine production by human monocytes-macrophages and T lymphocytes. Our results had shown that the levels of interleukin (IL)-1 beta, tumor necrosis factor (TNF)- alpha, and IL-6 in macrophage cultures treated with PS-G (100 micrograms/ml) were 5.1-, 9.8- and 29-fold higher, respectively, than those of untreated controls. In addition, the release of interferon (IFN)- gamma from T lymphocytes was also greatly promoted in the presence of PS-G (25-100 micrograms/ml). Furthermore, these cytokine-containing mononuclear cell-conditioned media (PSG-MNC-CM) were found to suppress the proliferation and clonogenicity of both the HL-60 and the U937 leukemic cell lines. DNA labeling and gel electrophoresis showed that treatment with PSG-MNC-CM markedly induced leukemic-cell apoptosis. Flow-cytometric analysis revealed that few (2.3 +/- 0.8%) apoptotic cells were seen in the control cultures, while PSG-MNC-CM treatment resulted in a significant increase in the apoptotic population both in the HL-60 (38.3 +/- 4.5%) and in the U937 (44.5 +/- 3.8%) cells. In addition, 40 to 45% of the treated leukemic cells were triggered to differentiate into mature monocytic cells expressing CD14 and CD68 surface antigens. However, PS-G alone had no such effects even at a higher dose of 400 micrograms/ml. Since untreated macrophages and T lymphocytes produced little or no cytokine, and normal MNC-CM did not suppress leukemic cell growth, it was suggestive that the anti-tumor activity of PSG-MNC-CM was derived from the elevated levels of cytokines. Antibody-neutralization studies further revealed that the anti-tumor cytokines in the PSG-MNC-CM were mainly of TNF- alpha and IFN- gamma, and these 2 cytokines acted synergistically on the inhibition of leukemic-cell growth.
Wang
S Y
SY
Department of Medical Research, Veterans General Hospital-Taipei, Taiwan, Republic of China.
Hsu
M L
ML
Hsu
H C
HC
Tzeng
C H
CH
Lee
S S
SS
Shiao
M S
MS
Ho
C K
CK
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001487:Basidiomycota / Q000737:chemistry*; D016207:Cytokines / Q000096:biosynthesis*; D003602:Cytotoxicity, Immunologic; D004354:Drug Screening Assays, Antitumor; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D007938:Leukemia / Q000188:drug therapy / Q000473:pathology; D018950:Lipopolysaccharide Receptors; D008262:Macrophage Activation / Q000187:drug effects / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects; D011134:Polysaccharides / Q000494:pharmacology*; D020940:Reishi; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D000097382:CD68 Molecule
D000276:Adjuvants, Immunologic; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000970:Antineoplastic Agents; D016207:Cytokines; D004365:Drugs, Chinese Herbal; D007375:Interleukin-1; D015850:Interleukin-6; D018950:Lipopolysaccharide Receptors; D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha; C067980:CD68 antigen, human; D000097382:CD68 Molecule