Effect of rosmarinic acid on diarrhea and tissue damage in mice caused by Salmonella enteritidis

ZHAO Linyi; YI Dandan; WANG Menghui; LI Yueyue; JIANG Nan; LIU Niu; LIANG Zhengmin; HE Jiakang

doi:10.13557/j.cnki.issn1002-2813.2025.13.013

Abstract：This experiment aimed to investigate the protective effect of rosmarinic acid(RA)against diarrhea and tissue damage in mice caused by Salmonella enteritidis(SE).A strain of SE was isolated and identified from the intestinal contents of diseased chickens through bacterial isolation and purification,biochemical identification,and 16S rRNA sequence analysis.A total of twenty-four 6 to 8 week old mice were randomly divided into four groups,with six replicates per group,and one mouse per replicate.Mice receive intraperitoneal injections of SE at concentrations of 108,109,1010,and 1011 CFU/mL,respectively.The time to diarrhea onset,diarrhea incidence,and survival rate were observed.Thirty mice were randomly divided into three groups,with 10 replicates per group,and one mouse per replicate.RA group was intragastrically administered with 20 mg/kg RA every day,control group(CON)and SE group were intragastrically administered with equal volume of normal saline for seven days.After 24 hours of administration on the seventh day,SE group and RA group were intraperitoneally injected with 0.2 mL SE(1010 CFU/mL),CON group was intraperitoneally injected with 0.2 mL normal saline.Body weight gain rate,fecal water content,diarrhea index,organ indices,histopathological examination,bacterial load in organs,and serum concentrations of inflammatory cytokines were monitored.The results showed that mice infected with SE developed clinical symptoms including diarrhea of varying severity.RA ameliorated the decrease in body weight,reduced fecal water content and diarrhea index,decreased the bacterial load in the liver,kidney,spleen,and lung,relieved damage to the liver,kidney,spleen,lung,duodenum,and colon,and reduced the serum concentrations of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),and interleukin-1β(IL-1β).The study indicates that RA exerted a protective effect against SE induced diarrhea and tissue damage in mice.