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ARS Home » Northeast Area » Beltsville, Maryland (BHNRC) » Beltsville Human Nutrition Research Center » Diet, Genomics and Immunology Laboratory » Research » Publications at this Location » Publication #356886

Title: Pomegranate peel extract reduced the pathogenicity of Citrobacter rodentium-infections in mice

item Smith, Allen
item George, Nadja
item Cheung, Lumei
item BHAGAVATHY, GANGA - Former ARS Employee
item Luthria, Devanand - Dave
item JOHN, KOLLAKONDAN - Former ARS Employee
item Bhagwat, Arvind

Submitted to: Nutrition Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2019
Publication Date: 1/1/2020
Citation: Smith, A.D., George, N.S., Cheung, L., Bhagavathy, G.V., Luthria, D.L., John, K.M., Bhagwat, A.A. 2020. Pomegranate peel extract reduced the pathogenicity of Citrobacter rodentium-infections in mice. Nutrition Research. 73:27-37.

Interpretive Summary: Pomegranates are a good source of polyphenols, which are thought to be beneficial for your health. We took pomegranate peels, and extracted the polyphenols (PPX) and gave mice the extract for two weeks. Mice were then infected them with a bacteria, Citrobacter rodentium, that causes an infection in the colon called colitis that damages the colon and is similar to E. coli that causes disease in humans. Untreated, infected mice developed severe colitis with significant damage to the colon tissue that was significantly reduced in PPX treated infected mice. This changed occurred without any measureable change to the level of Citrobacter rodentium level in the colon or the immune response to the infection. However, untreated infected mice had significantly more bacteria breaking through the barrier in the colon causing a systemic infection that sometimes resulted in mortality. In addition to reducing the amount of damage to the colon, PPX treatment also helped preserve the ability of the colon to produce a protective substance called mucus. Thus, pomegranate peels are a source of compounds that can protect the colon from a common bacterial infection that is often obtained from contaminated food.

Technical Abstract: We investigated the effects of a pomegranate peel extract (PPX) on the pathogenicity of Citrobacter rodentium (Cr) infections in mice. Mice were orally administered PPX for 10-14 days prior to infection with Cr and for the duration of the experiment. Fecal excretion of Cr was monitored for 19 days and mice were also sacrificed on day 12 post-infection to assess Cr colonization of the colon and spleen, histological changes, and gene expression. Water-treated infected mice lost significant weight during the first two-weeks of infection compared to PPX-treated infected mice. Mortality was observed in water-treated but none of the PPX-treated infected mice. Cr colonization of the colon was similar between water- and PPX-treated mice. Consistent with this, PPX treatment did not alter the potent Th1/Th17 pro-inflammatory response elicited by Cr infection. Significant colonization of the spleen was only seen in water-treated mice. Spleen colonization was linearly correlated with the dose of PPX administered to the mice with increased spleen colonization occurring with decreasing concentrations of PPX. The examination of H&E stained colon sections indicated that PPX treatment decreased the extent of Cr-induced damage to the colon that is consistent with the reduced translocation of bacteria in PPX treated mice.