RESUMO
This study evaluated the probiotic properties, safety profile, and antioxidative and immune system-enhancing effects of Enterococcus faecium strains isolated from human infant feces. E. faecium KU22001, E. faecium KU22002, and E. faecium KU22005 exhibited potential probiotic properties; however, to eliminate concerns about toxin production and antibiotic resistance, the E. faecium strains were heat-treated prior to experimental usage. E. faecium KU22001 showed the highest antioxidant activity and lowest reactive oxygen species production among the three strains. The immune system-enhancing effects of heat-killed E. faecium strains were evaluated using a nitric oxide assay. E. faecium KU22001 induced an increase in the mRNA expression of inducible nitric oxide synthase, cyclooxygenase-2, and proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1ß, and interleukin-6 in RAW 264.7 cells. Furthermore, E. faecium KU22001 activated the mitogen-activated protein kinase pathway, which was a key regulator of the immune system. These results demonstrate the potential use of E. faecium KU22001 as a multifunctional food material.
Assuntos
Antioxidantes , Citocinas , Enterococcus faecium , Fezes , Probióticos , Probióticos/farmacologia , Camundongos , Animais , Células RAW 264.7 , Humanos , Antioxidantes/metabolismo , Citocinas/metabolismo , Fezes/microbiologia , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Ciclo-Oxigenase 2/metabolismo , Ciclo-Oxigenase 2/genética , Temperatura Alta , Interleucina-6/metabolismo , Interleucina-6/genética , Fatores Imunológicos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/genética , Macrófagos/imunologia , Macrófagos/efeitos dos fármacos , Interleucina-1beta/metabolismo , Interleucina-1beta/genéticaRESUMO
The anti-cancer effects of heat-killed Enterococcus faecium KU22001 (KU22001), KU22002, and KU22005 isolated from human infant feces were investigated. The anti-proliferative activity of these strains against various cancer cell lines was evaluated using the MTT assay. To determine the production of exopolysaccharides (EPS) with potential anti-cancer effect, ethanol precipitation and phenol-sulfuric acid method was used with the cell free supernatant of strains grown at 25°C or 37°C. The EPS yield of E. faecium strains was higher at 25°C than at 37°C. Among these E. faecium strains, KU22001 grown at 25°C was associated with the highest bax/bcl-2 ratio, effective apoptosis rate, cell cycle arrest in the G0/G1 phase, and condensation of the nucleus in the cervical cancer HeLa cell line. In conclusion, these results suggest that KU22001 can be beneficial owing to the anti-cancer effects and production of functional materials, such as EPS.