Exploring in vitro effects of biotransformed isoflavones extracts: Antioxidant, antiinflammatory, and antilipogenic

The present study aimed to investigate, in in vitro assays, the antilipogenic and antiinflammatory potential as well as the antioxidant capacity of biotransformed soymilk by tannase and β‐glycosidase enzymes. The results showed a significant enhancement of the antioxidant capacity, especially by biotransformed soymilk with free tannase (SFT), corresponding to an increase of 2.3 and 1.25 times by oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays, respectively. The lipid accumulation reduction by 3T3‐L1 adipocytes assay was not significant. However, the antiinflammatory responses were expressive. In lipopolysaccharide‐stimulated RAW 264.7 macrophages, SFT reduced around 37 times TNF‐α expression at the highest tested concentration of the sample. Other inflammatory parameters, as IL‐6 and nitric oxide, were no longer detected when the cells were treated with SFT and soymilk with immobilized enzymes, respectively. The biotransformed soy extracts with tannase have great potential to act as a nutraceutical, protecting the cells against oxidative damage and helping maintain health under inflammatory stress. Practical applications Soy isoflavones have been associated with several beneficial effects on human health, including inhibition capacity of lipid accumulation in adipocytes, antiinflammatory properties, and antioxidant potential. However, the isoflavones bioavailability differs among their chemical forms, and studies have shown that the higher health benefits are conferred by aglycones and their metabolites, such as equol, compared to the other forms. For this reason, the enrichment of isoflavone aglycones and metabolites in soy‐based products has attracted growing attention. The present study was focused on developing a bioprocess able to produce a rich extract with soy isoflavones metabolites, with increased bioactive potential for application as a functional ingredient or a nutraceutical. Tannase biotransformation increased the aglycones and equol content of soymilk. Biotransformed soymilk by free tannase had higher antioxidant capacity. Biotransformed soy extracts presented expressive antiinflammatory activity.