Hesperetin Inhibits Expression of Virulence Factors and Growth of Helicobacter pylori

Abstract

<i>Helicobacter pylori</i> (<i>H. pylori</i>) is a bacterium known to infect the human stomach. It can cause various gastrointestinal diseases including gastritis and gastric cancer. Hesperetin is a major flavanone component contained in citrus fruits. It has been reported to possess antibacterial, antioxidant, and anticancer effects. However, the antibacterial mechanism of hesperetin against <i>H. pylori</i> has not been reported yet. Therefore, the objective of this study was to determine the inhibitory effects of hesperetin on <i>H. pylori</i> growth and its inhibitory mechanisms. The results of this study showed that hesperetin inhibits the growth of <i>H. pylori</i> reference strains and clinical isolates. Hesperetin inhibits the expression of genes in replication (<i>dna</i>E, <i>dna</i>N, <i>dna</i>Q, and <i>hol</i>B) and transcription (<i>rpo</i>A, <i>rpo</i>B, <i>rpo</i>D, and <i>rpo</i>N) machineries of <i>H. pylori</i>. Hesperetin also inhibits the expression of genes related to <i>H. pylori</i> motility (<i>flh</i>A, <i>fla</i>A, and <i>flg</i>E) and adhesion (<i>sab</i>A, <i>alp</i>A, <i>alp</i>B, <i>hpa</i>A, and <i>hop</i>Z). It also inhibits the expression of urease. Hespereti n downregulates major virulence factors such as cytotoxin-associated antigen A (CagA) and vacuolating cytotoxin A (VacA) and decreases the translocation of CagA and VacA proteins into gastric adenocarcinoma (AGS) cells. These results might be due to decreased expression of the type IV secretion system (T4SS) and type V secretion system (T5SS) involved in translocation of CagA and VacA, respectively. The results of this study indicate that hesperetin has antibacterial effects against <i>H. pylori</i>. Thus, hesperetin might be an effective natural product for the eradication of <i>H. pylori.</i>