Cloning, characterization of β-glucosidase from Furfurilactobacillus rossiae in bioconversion and its efficacy

Minor ginsenosides produced by β-glucosidase are interesting biologically and pharmacologically. In this study, new ginsenoside-hydrolyzing glycosidase from Furfurilactobacillus rossiae DCYL3 was cloned and expressed in Escherichia coli strain BL21. The enzyme converted Rb1 and Gyp XVII into Rd and compound K following the pathways: Rb1→Rd and Gyp XVII→F2→CK, respectively at optimal condition: 40 °C, 15 min, and pH 6.0. Furthermore, we examined the cytotoxicity, NO production, ROS generation, and gene expression of Gynostemma extract (GE) and bioconverted Gynostemma extract (BGE) in vitro against A549 cell lines for human lung cancer and macrophage RAW 264.7 cells for antiinflammation, respectively. As a result, BGE demonstrated significantly greater toxicity than GE against lung cancer at a dose of 500 µg/mL but in normal cells showed lower toxicity. Then, we indicated an enhanced generation of ROS, which may be boosting cancer cell toxicity. By blocking the intrinsic way, BGE increased p53, Bax, Caspase 3, 9, and while Bcl2 is decreased. At 500 µg/mL, the BGE sample was less toxic in normal cells and decreased the LPS-treated NO and ROS level to reduce inflammation. In addition, BGE inhibited the expression of pro-inflammatory genes COX-2, iNOS, IL-6, and IL-8 in RAW 264.7 cells than the sample of GE. In conclusion, FrBGL3 has considerable downstream applications for high-yield, low-cost, effective manufacture of minor ginsenosides. Moreover, the study's findings imply that BGE would be potential materials for anti-cancer and anti-inflammatory agent after consideration of future studies.