Antibacterial activity of the soy isoflavone genistein

Abstract

Genistein, a radioprotective soy isoflavone and protein kinase inhibitor, blocks the invasion of pathogenic bacteria in mammalian epithelial cells. The purpose of this study was to evaluate the direct effect of genistein on the survival and growth of the probiotic Lactobacillus reuteri and selected opportunistic bacteria in vitro as a prelude to in vivo use for managing postirradiation sepsis. We evaluated the opportunistic bacterial enteropathogens Escherichia coli, Shigella sonnei, and Staphylococcus aureus as well as Klebsiella pneumoniae and the non-pathogenic organism, Bacillus anthracis (Sterne). The latter two bacteria are found in the environment and may be of concern in irradiated individuals. A standard in vitro test was employed to evaluate the direct effect of genistein on the bacteria. This test involved determining bacterial colony forming unit (CFU) counts at a single concentration of genistein. In the CFU assays, significant reductions in CFUs were found for S. aureus and B. anthracis when cultured in the presence of 100 muM genistein. However, L. reuteri, E. coli, S. sonnei, and K. pneumoniae were not altered by in vitro culturing in the presence of 100 muM genistein. These results demonstrate the in vitro antimicrobial activity of genistein. Furthermore, the use of genistein in combination with probiotics may augment the effectiveness of antimicrobial therapies currently used in the management of infections, including those induced by ionizing irradiation.

Antibacterial Potential of Capparis spinosa and Capparis decidua Extracts

“…Recently, many plants have been explored and reported for their ability to inhibit the growth of microorganisms, which can replace the chemically manufactured drugs (Ilic et al, 2004;Mandalari et al, 2007). Consequently, plant based compounds like isoflavones, gamma thionin and homoisoflavinoids have been discovered and studied extensively (Hong et al, 2006;Franco et al, 2006;Mhaeswara et al, 2006). Additionally, sulfur rich plant extracts have been studied and their potential against bacterial pathogens has been reported (Iscan et al, 2002;Kalemba and Kunicka, 2003).…”

CAROB (Ceratonia siliqua): HEALTH, MEDICINE, CHEMISTRY

“…For example, n-nonadecanol from Schinus lentiscifolius, 185 lupeol from Albizia adianthifolia, 186 genisstein from soybean (Glycine max), 187 geraldone from Flourensia oolepis, 188 and liquiritigenin from Dalbergia odorifera. (Figure 2) from the methnolic extract of Carob leaves.…”

Genistein Derivatization – From a Dietary Supplement to a Pharmaceutical Agent

“…Antimicrobial properties of genistein are described in many papers, although the exact mechanism of this activity remains largely unknown (Hong et al, 2006;Ulanowska et al, 2006;Verdrengh et al, 2004). Cell survival studies suggest that genistein is a bacteriostatic, rather than a bactericidal agent (Ulanowska et al, 2007).…”