Dados do Trabalho

Título

BIOTRANSFORMED SOY ISOFLAVONES MODULATING MICROGLIA INFLAMMATION

Introdução

Soy isoflavones have attracted special attention owing to their potential benefits on human health. Since isoflavones predominantly exist in glycoside forms in soybeans, our research group has been investigating the application of tannase in biotransformation processes of soy polyphenols in order to generate rich aglycones extracts. Studies have demonstrated the protective effects of soy isoflavones in neuronal disorders and the microglial in vitro model has been widely used for this purpose. In this context, this study assessed, using an in vitro cell model, the expression of pro-inflammatory markers on microglia M1 phenotype in response to the treatment of enzymatically biotransformed soymilk. As microglia cells are involved with the modulation of synaptic structures, the expression of synapsin I in neurons was also explored.

Material e Métodos

For evaluating the mRNA expression of pro-inflammatory markers (TNF-α, IL-1β, IL-6, iNOS, and MCP1) by real-time PCR, LPS-stimulated N9 microglial cells were treated with enzymatically biotransformed soy extracts by β-glycosidase and tannase, in immobilized and free forms, or 17β-estradiol. After that, SH-SY5Y neuroblastoma cells were exposed to the microglial conditioned medium for investigation of synapsin I neuronal transcription.

Resultados e Discussão

The results showed that all enzymatically biotransformed samples, especially biotransformed soymilk with free tannase (SFT), presented a decrease in the expression of pro-inflammatory markers compared to LPS control, being as effective and, most of the time, acting better than the 17β-estradiol hormone. A major reduction was observed by SFT sample to IL-1β and TNF-α mRNA expressions, corresponding to a decrease of 2.8 and 3.1 times, respectively. However, in the studied conditions, microglia-neuron interaction was not observed.
Discussion and conclusions

Conclusão

Our results corroborate those found by Chen et al. (2008) and Chinta et al. (2013), that also observed a reduction of pro-inflammatory mediators after treatment with isoflavones in microglial cells induced by LPS. Biotransformed soymilk rich in aglycones showed an expressive increase in anti-inflammatory power on microglia cells and appears as a possible neurotherapeutic strategy. This is the first in vitro evaluation that shows the protective effect of biotransformed soymilk by tannase in the modulation of microglial inflammation.