Bioconversion of glycosides isoflavones to aglycone isoflavones by Lactobacillus rhamnosus BHN-LAB 76 under anaerobic conditions

Abstract

Isoflavones exhibit an estrogenic activity and have been reported extensively for their potential role in preventing chronic diseases, such as cancer, osteoporosis, and postmenopausal syndrome. Pueraria is a medicinally important leguminous plant producing several glycoside isoflavones, such as daidzin, daidzein, genistin, and puerarin. However, daidzin and genistin mainly exist as nonabsorbable and biologically inactive glycosides. The bioavailability of glucosides is increased by hydrolysis of the sugar moiety using β-glucosidase. Furthermore, intestinal microorganisms can enhance the biological activity of these isoflavones through biotransformation. Lactic acid bacteria (LAB) are typical probiotic microorganisms used in fermented foods, as feed additives, and in pharmaceuticals. Therefore, we isolated Lactobacillus rhamnosus BHN-LAB 76 from Korean traditional fermented food and assessed its isoflavone-transforming activity in the production of daidzein using HPLC. The Pueraria lobata extract was fermented with L. rhamnosus BHN-LAB 76 for 72 h at 37℃ under anaerobic conditions. L. rhamnosus BHN-LAB 76 could convert about 25% of daidzin to daidzein. These results confirmed the potential of L. rhamnosus BHN-LAB 76 as a probiotic culture, which can be utilized in the manufacture of fermented and functional foods.

Antioxidant Effect via Bioconversion of Isoflavonoid in Astragalus membranaceus Fermented by Lactiplantibacillus plantarum MG5276 In Vitro and In Vivo

“…Calycosin and formononetin are bound to 7-O-glucoside, which can be degraded by the β-glucosidase produced by L. plantarum [25]. In addition, many studies have been conducted using lactic acid bacteria for the bioconversion of glycosides to aglycones of bioactive compounds [23,26,27]. In our previously study, we only confirmed that calycosin content was increased by MG5276 fermentation [15].…”

“…pathway [28]. Isoflavonoid glycosides have a very low absorption rate in the body; therefore, a bioconversion process that converts them into an isoflavonoid aglycone is urgently needed to compensate for this [27]. Therefore, conversion to aglycone is important for increasing bioactivity by increasing absorption in the body.…”