en Genetics Genetics پژوهشي Orginal research papers <span lang="TR" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""><span style="color:black">The increasing prevalence of antibiotic resistance has led researchers to search for pharmaceutical products that can replace antibiotics or be used in combination with them. Among natural compounds, brown algae extract can have inhibitory effects on bacteria. In the present study, the effect of <i>Sargassum glaucescens</i> extract on virulence gene expression and its anticancer potential was investigated. Stool samples were collected from gastrointestinal infection individuals referred to Imam Khomeini and Milad Hospitals in Tehran from March 21, 2022, to September 21, 2022. <i>Salmonella typhi</i> isolates were identified using phenotypic and chemical tests. Next, <i>Vir</i> gene was confirmed through a polymerase chain reaction (PCR). In the next step, the minimum inhibitory concentration (MIC) of the methanolic extract of <i>S</i>. <i>glaucescens</i> was determined<i>.</i> Furthermore, the expression level of Vir, P53, and Bcl-2 was investigated using the Real-Time PCR method. Among 110 collected samples, 60 isolates of <i>S</i>. <i>typhi</i> were identified, all of which had the <i>Vir</i> gene. The MIC of the methanolic extract was <i>S</i>. <i>glaucescens</i> 16 &mu;g/ml. The expression level of Vir and Bcl-2 in Caco₂ cells infected with S. typhi, and treated with <i>S</i>. <i>glaucescens </i>extract was significantly decreased (<i>p</i>˂0.001). </span></span></span><span lang="EN" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""><span style="color:black">Besides, the expression level of P53 showed a significant increase </span></span></span><span lang="TR" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""><span style="color:black">(<i>p</i><0.0001). The obtained results showed that</span></span></span><span lang="TR" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> <span style="color:black">the methanolic extract of</span> <i><span style="color:black">S. glaucescens</span></i> <span style="color:black">has strong anti-bacterial and anti-cancer effects.</span></span></span> Salmonella typhi, Vir, Brown algae, Real-Time PCR, Sargassum glaucescens, Virulence genes 1495 1509 http://jifro.ir/browse.php?a_code=A-10-4196-2&slc_lang=en&sid=1 M. Hassannia mohidream76@gmail.com 100319475328460058206 100319475328460058206 No Department of Biology, East Tehran Branch, Islamic Azad University, Tehran, Iran E. Aliasgari e.asgari@gmail.com 100319475328460058207 100319475328460058207 Yes Department of Biology, East Tehran Branch, Islamic Azad University, Tehran, Iran M. Kavousi mahsa kavosi 100319475328460058208 100319475328460058208 No Department of Biology, East Tehran Branch, Islamic Azad University, Tehran, Iran