title: Tumoricidal effects of a selenium (Se)-polysaccharide from Ziyang green tea on human osteosarcoma U-2 OS cells.
abstract: Selenium(Se)-enriched green tea consumption in human diets is well-known to reduce the risk of a variety of diseases. Here, we isolated a Se-polysaccharide (Se-ZYTP) from Se-enriched Ziyang green tea and investigated its antitumor activity on human osteosarcoma U-2 OS cells in vitro and in vivo. Se-ZYTP contained 94.5% of carbohydrate and 2.1% of uronic acid, as well as 2.14 μg/g Se, revealing that Se-ZYTP was an acidic Se-conjugated polysaccharide. Monosaccharide composition analysis indicated that Se-ZYTP consisted of mannose, rhamnose and fucose in molar ratios of 2.4:1.5:1.2:0.2:0.1:0.3:0.3. In vitro, both MTT and LTH assays proved that Se-ZYTP (25, 50, 100 and 200 μg/ml) could significantly inhibit the proliferation of human osteosarcoma U-2 OS cells in a concentration-dependent fashion (P<0.05 or P<0.01). In U-2 OS cancer xenograft model in BALB/c athymic mice, Se-ZYTP oral administration at three doses of 100, 200 and 400mg/kg body weight (B.W.) daily for 28 days resulted in obvious tumor regression as compared to model control (P<0.05 or P<0.01). In addition, body weights of mice in control or Se-ZYTP treated groups did not differ significantly and no mice died during experiment, suggesting the safety of Se-ZYTP. Therefore, we postulate that Se-ZYTP might have cancer-preventive and cancer-therapeutic benefit for human osteosarcoma.
authors.affiliation: Department of Orthopaedic Surgery, Tangdu Hospital, the Fourth Military Medical University, Xi'an 710038, China.
authors.forename: Yucai
authors.initials: Y
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Dianzhong
authors.initials: D
authors.lastname: Zhang
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Wen
authors.forename: Lihong
authors.initials: L
authors.lastname: Li
authors.forename: Lianhe
authors.initials: L
authors.lastname: Zheng
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D006801:Humans; D051379:Mice; D016566:Organoselenium Compounds / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D012516:Osteosarcoma / Q000473:pathology*; D011134:Polysaccharides / Q000737:chemistry*; D013662:Tea / Q000737:chemistry*; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D016566:Organoselenium Compounds; D011134:Polysaccharides; D013662:Tea
keywords: Osteosarcoma; Purification; Selenium-polysaccharide; Tumoricidal; Ziyang green tea