ABSTRACT
Aims: To evaluate the antitumor potential of metal silver and polyvinilpyrrolidone nanoparticle-encapsulated silver on L5178Y-R murine lymphoma cell growth and survival of tumor-bearing mice. Study Design: In vitro and in vivo (pre-clinical) study. Place and Duration of Study: Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Departamento de Microbiología e Inmunología, San Nicolás de los Garza, N.L., México, from January 2009 to December 2011. Methodology: Concentration-response cell viability assay was performed in vitro and mice survival studies were done using a L5178Y-R tumor-bearing mouse model. The PROBIT regression analysis was performed to determine the in vitro LC50. In vivo survival distributions were calculated by Kaplan-Meier and Cutler-Ederer analysis, and survival curves comparisons and hypothesis testing was done using the log-rank method. Results: Metal silver induced up to 100% L5178Y-R cells cytotoxicity, with an LC50 of 1.8 X 10-8 M, whereas silver nanoparticles caused up to 78% cytotoxicity, with an LC50 of 14.4 X 10-8 M. In addition, Intramuscular administration of metal silver and silver nanoparticles administered at the time of tumor injection significantly (P = .05) increased mice survival, where 70% and 60% of mice survived at day 35 respectively, as compared with such treatments administered 7 days after tumor induction (55% and 25% survival respectively); vincristine treatment caused 50% mice survival and tumor-bearing control mice had 20% survival. These results open further approaches on treating several types of cancer using free and nanoparticle-encapsulated silver-based therapies
ABSTRACT
Aims: To determine the antibacterial effect of Oenothera rosea against Escherichia coli, Salmonella enteritidis and Vibrio cholerae. Study Design: In vitro antibacterial study. Place and Duration of Study: Universidad Autónoma de Nuevo León, Facultad de Ciencias Biológicas, Departamento de Microbiología e Inmunología and Departamento de Química, San Nicolás de los Garza, NL. México, from June 2010 to June 2011. Methodology: The antibacterial in vitro effect of methanol and aqueous extracts of the Mexican plant O. rosea against strains of E. coli, S. enteritidis and V. cholerae was evaluated in liquid medium by the colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium bromide (MTT) reduction assay. Results: Methanol and aqueous extracts significantly inhibited growth of all bacterium strains tested. The methanol extract caused up to 55%, 66% and 87% growth against E. coli, S. enteritidis and V. cholerae, respectively, whereas the aqueous extract induced up to 54%, 69% and 88% bacterial growth inhibition, respectively. Methanol and aqueous vehicle controls did not alter bacterial growth. Conclusion: The observed antibacterial effect of O. rosea extracts may be of benefit as an adjuvant treatment of diseases caused by the studied enterobacteria.