Supplementation with Selenium yeast on the prooxidant-antioxidant activities and anti-tumor effects in breast tumor xenograft-bearing mice.
Selenium (Se) is essential for antioxidant activity involved in immune function and anti-carcinogenic action, whereas at higher concentrations, Se may have pro-oxidant properties. The present study was aimed at determining the effects of Se supplementation, as Se yeast, on oxidative stress in non-tumor/tumor tissues, as well as regulation of the apoptotic process, and immune responses in mice-bearing breast tumor xenografts. Female BALB/cByJNarl mice were divided into control (CNL and CNL-con), Se-supplemented control (CNL-HS, given as a single oral dose of 912 ng Se daily), breast tumor-bearing (TB and TB-con), TB-LS (228 ng Se), TB-MS (456 ng Se) and TB-HS (912 ng Se) groups. All mice were treated with/without Se for 14 days. A number of variables were further measured. Compared with the TB groups, tumor bearing mice with Se supplement had increased plasma Se concentrations, reduced erythrocyte Se-dependent glutathione peroxidase (GPx) activity and malondialdehyde (MDA) products and inhibited tumor growth. They have also higher Se concentrations in non-tumor and tumor tissues. Significantly elevated concentrations of MDA and reduced GPx activities, as well as increased anti-apoptotic bcl-2 and tumor suppressor p53 concentrations in tumor tissues were observed as Se accumulated in tumor, whereas lower MDA products were found in various non-tumor tissues than did the corresponding values. Further, there were elevated concentrations of Th1-derived cytokines and decreased Th2-type interleukin (IL)-4 in tumor-bearing mice with the treatment of Se. In conclusion, accumulation of Se in tumors may induce oxidative stress and p53-dependent pro-oxidative apoptosis, thus inhibiting the growth of breast tumor.
Institute of Biomedical Nutrition, Hung-Kuang University, Taichung, 433, Taiwan; Department of Medical Research, China Medical University Hospital, Taichung, 404, Taiwan; Department of Health and Nutrition Biotechnology, Asia University, Taichung, 413, Taiwan; Taiwan Nutraceutical Association, Taipei 115, Taiwan. Electronic address: eillyguo@sunrise.hk.edu.tw.
Chih-Hung
CH
Guo
Institute of Biomedical Nutrition, Hung-Kuang University, Taichung, 433, Taiwan; Taiwan Nutraceutical Association, Taipei 115, Taiwan.
Simon
S
Hsia
Department of Nursing, Hung-Kuang University, Taichung, 404, Taiwan; School of Nursing, China Medical University, Taichung, 404, Taiwan.
Der-Yun
DY
Hsiung
Taiwan Nutraceutical Association, Taipei 115, Taiwan; College of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan; College of Engineering, National Chiao Tung University, Hsinchu, 300, Taiwan. Electronic address: chenpc.hk@gmail.com.
Pei-Chung
PC
Chen
D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry; D000975:Antioxidants / Q000737:chemistry*; D017209:Apoptosis; D001835:Body Weight; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D016207:Cytokines / Q000378:metabolism; D019587:Dietary Supplements; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D007249:Inflammation; D008315:Malondialdehyde / Q000737:chemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D016877:Oxidants / Q000737:chemistry*; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D012643:Selenium / Q000737:chemistry*; D018417:Th1 Cells / Q000166:cytology; D018418:Th2 Cells / Q000166:cytology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays; D015003:Yeasts / Q000737:chemistry
D000970:Antineoplastic Agents; D000975:Antioxidants; D016207:Cytokines; D016877:Oxidants; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D012643:Selenium; D010100:Oxygen
Apoptosis; Breast cancer; Mice; Oxidative stress; Selenium yeast