title: Anti-metastatic effect of polysaccharide isolated from Colocasia esculenta             is exerted through immunostimulation.
abstract: In the present study, an edible corm of the plant Colocasia esculenta, commonly known as Taro was extracted with cold water (4˚C). Finally, 10.44 g (1.04%) of the crude polysaccharide (Taro-0) was obtained from Taro. The purified active compound (Taro-4-I) was isolated using DEAE-Sepharose FF and Sephadex G-100. The anti-complementary activity of Taro-4-I (57.3±4.5%) was similar to that of polysaccharide K (used as the positive control). The molecular weight of Taro-4-I was 200 kDa and it was a polysaccharide composed of 64.4% neutral sugars and 35.6% uronic acid. Taro-4-I activated the complement system through the classical and alternative pathways. The treatment of peritoneal macrophages with Taro-4-I significantly increased the production of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) in a dose-dependent manner. However, IL-12 production showed maximal activity at 56 µg/ml and subsequently decreased. Splenocytes obtained from mice which were administered Taro-4-I intravenously showed a higher toxicity to Yac-1 cells compared to those obtained from untreated mice in a effector‑to‑target (E/T) ratio-dependent manner. The group treated with 50 µg/ml Taro-4-I showed a significantly increased toxicity to Yac-1 cells compared to the group treated with 500 µg/ml Taro-4-I. The administration of Taro-4-I significantly inhibited the lung metastasis of B16BL6 melanoma cells. However, the group treated with 50 µg/mouse Taro-4-I had a significantly lower number of tumors compared to the group injected with 500 µg/mouse Taro-4-I.
authors.affiliation: Department of Food Science and Biotechnology, Kyonggi University,                     Suwon-Si, Gyeonggi 443-760, Republic of Korea.
authors.forename: Hye-Ryung
authors.initials: HR
authors.lastname: Park
authors.forename: Hyun-Sun
authors.initials: HS
authors.lastname: Lee
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Cho
authors.forename: Yoon-Sook
authors.initials: YS
authors.lastname: Kim
authors.forename: Kwang-Soon
authors.initials: KS
authors.lastname: Shin
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D031060:Colocasia / Q000737:chemistry*; D003167:Complement Activation / Q000187:drug effects; D005260:Female; D018664:Interleukin-12 / Q000276:immunology; D008168:Lung / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology / Q000556:secondary*; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D008545:Melanoma / Q000188:drug therapy / Q000276:immunology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000972:Antineoplastic Agents, Phytogenic; D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12