title: Antitumor and immunostimulating effects of Anoectochilus formosanus Hayata.
abstract: The water extract of Anoectochilus formosanus Hayata showed a potent tumor inhibitory activity in BALB/c mice after subcutaneous transplantation of CT-26 murine colon cancer cells. The tumor-inhibition ratios of mice pre-administered with A. formosanus for 2 days before tumor transplantation, and treated further for 12 consecutive days, were 55.4% and 58.9% at the oral dose of 50 and 10 mg/mouse per day, respectively. Even for the tumor-bearing mice, after oral administration of the water extract of A. formosanus for 12 consecutive days, the tumor inhibition ratios were still 23.8% and 40.5% at doses of 50 and 10 mg/mouse, respectively. Because the low-concentration water extract of A. formosanus does not show direct cytotoxicity in CT-26 tumor cells, we observed further that oral administration of the water extract of A. formosanus may activate murine immune responses, such as stimulating the proliferation of lymphoid tissues and activating the phagocytosis of peritoneal macrophages against Staphylococcus aureus. This study suggests that the antitumor activity of A. formosanus may be associated with its potent immunostimulating effect. It is worth further analyzing the immunomodulating component purified from A. formosanus, and evaluating its potential value for the treatment of human cancers.
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: C-C
authors.initials: CC
authors.lastname: Tseng
authors.forename: H-F
authors.initials: HF
authors.lastname: Shang
authors.forename: L-F
authors.initials: LF
authors.lastname: Wang
authors.forename: B
authors.initials: B
authors.lastname: Su
authors.forename: C-C
authors.initials: CC
authors.lastname: Hsu
authors.forename: H-Y
authors.initials: HY
authors.lastname: Kao
authors.forename: K-T
authors.initials: KT
authors.lastname: Cheng
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor / Q000187:drug effects; D003110:Colonic Neoplasms / Q000188:drug therapy*; D005260:Female; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects*; D017737:Macrophages, Peritoneal / Q000187:drug effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D029595:Orchidaceae / Q000737:chemistry*; D010587:Phagocytosis / Q000187:drug effects; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000276:immunology; D018675:Toxicity Tests / Q000379:methods
chemical_list: D000276:Adjuvants, Immunologic; D000970:Antineoplastic Agents; D010936:Plant Extracts