title: Antitumor activity of colloidal silver on MCF-7 human breast cancer cells.
abstract: BACKGROUND
  Colloidal silver has been used as an antimicrobial and disinfectant agent. However, there is scarce information on its antitumor potential. The aim of this study was to determine if colloidal silver had cytotoxic effects on MCF-7 breast cancer cells and its mechanism of cell death.
  
  
  METHODS
  MCF-7 breast cancer cells were treated with colloidal silver (ranged from 1.75 to 17.5 ng/mL) for 5 h at 37°C and 5% CO2 atmosphere. Cell Viability was evaluated by trypan blue exclusion method and the mechanism of cell death through detection of mono-oligonucleosomes using an ELISA kit and TUNEL assay. The production of NO, LDH, and Gpx, SOD, CAT, and Total antioxidant activities were evaluated by colorimetric assays.
  
  
  RESULTS
  Colloidal silver had dose-dependent cytotoxic effect in MCF-7 breast cancer cells through induction of apoptosis, shown an LD50 (3.5 ng/mL) and LD100 (14 ng/mL) (*P < 0.05), significantly decreased LDH (*P < 0.05) and significantly increased SOD (*P < 0.05) activities. However, the NO production, and Gpx, CAT, and Total antioxidant activities were not affected in MCF-7 breast cancer cells. PBMC were not altered by colloidal silver.
  
  
  CONCLUSIONS
  The present results showed that colloidal silver might be a potential alternative agent for human breast cancer therapy.
authors.affiliation: Laboratorio de Inmunología y Virología, Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas de la Universidad Autónoma de Nuevo León, San Nicolás de los Garza, N, L, México. moyfranco@gmail.com
authors.forename: Moisés A
authors.initials: MA
authors.lastname: Franco-Molina
authors.forename: Edgar
authors.initials: E
authors.lastname: Mendoza-Gamboa
authors.forename: Crystel A
authors.initials: CA
authors.lastname: Sierra-Rivera
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Gómez-Flores
authors.forename: Pablo
authors.initials: P
authors.lastname: Zapata-Benavides
authors.forename: Paloma
authors.initials: P
authors.lastname: Castillo-Tello
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Alcocer-González
authors.forename: Diana F
authors.initials: DF
authors.lastname: Miranda-Hernández
authors.forename: Reyes S
authors.initials: RS
authors.lastname: Tamez-Guerra
authors.forename: Cristina
authors.initials: C
authors.lastname: Rodríguez-Padilla
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003102:Colloids; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling; D012834:Silver / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D003102:Colloids; D012834:Silver