title: Bactericidal activity of soymilk fermentation broth by in vitro and animal models.
abstract: Soybean fermentation broth (SFB) exhibits potent antibacterial activity against different species of bacteria in in vitro assays and animal models. Four isoflavone compounds-daidzin, genistin, genistein, and daidzein-of SFB were analyzed and quantified by high-performance liquid chromatography. In the in vitro test, daidzin and daidzein had more potent antibacterial activity than genistin. The minimum inhibition concentration values for these bacteria of SFB ranged from 1.25% to 5%, and the minimum bactericidal concentration values of strains ranged from 2.5% to 10%, depending on the species or strain. Vancomycin-resistant Entercoccus faecalis (VRE) strains were also tested for susceptibility to SFB in two species of animal model: the Sprague-Dawley rat and the BALB/c mouse. SFB-fed Sprague-Dawley rats showed excellent elimination efficiency against VRE, close to 99% compared with the phosphate-buffered saline-fed control group. In the BALB/c mouse model, SFB antibacterial activity was 65-80% against VRE compared with the control. In conclusion, SFB contains natural antibacterial substances such as daidzin, genistin, and daidzein that inhibit bacterial growth.
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Chin
authors.forename: Ko-Chung
authors.initials: KC
authors.lastname: Tsui
authors.forename: Mei-Chieh
authors.initials: MC
authors.lastname: Chen
authors.forename: Cheng-Yi
authors.initials: CY
authors.lastname: Wang
authors.forename: Chin-Yuh
authors.initials: CY
authors.lastname: Yang
authors.forename: Yuh-Ling
authors.initials: YL
authors.lastname: Lin
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004195:Disease Models, Animal; D013293:Enterococcus faecalis / Q000187:drug effects*; D005285:Fermentation; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D007529:Isoflavones / Q000032:analysis / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008826:Microbial Sensitivity Tests; D051381:Rats; D017207:Rats, Sprague-Dawley; D041942:Soy Milk / Q000494:pharmacology*; D013025:Glycine max / Q000737:chemistry*; D020713:Vancomycin Resistance / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D007529:Isoflavones