Effect of the flavonoid quercetin on inflammation and lipid peroxidation induced by Helicobacter pylori in gastric mucosa of guinea pig.
BACKGROUND
Helicobacter pylori infection induces an inflammatory response in the gastric mucosa. Activation of polymorphonuclear leukocytes can produce oxidative damage to gastric tissue through intermediary radicals of oxygen and nitrogen. Vegetable extracts containing polyphenols of the flavonoid family have antibacterial activity, and the flavonoid quercetin possesses anti-H. pylori activity in vitro. The aim of this study was to analyze the effect of oral administration of pure quercetin on inflammation and lipid peroxidation induced by H. pylori in the gastric mucosa of the guinea pig.


METHODS
Sixty days after oral infection with H. pylori guinea pigs received 200 mg/kg of quercetin daily by mouth for 15 days. The infiltration index of inflammatory cells and bacterial density in both the pyloric antrum and corpus were histologically determined by myeloperoxidase histochemistry, hematoxylin-eosin, and modified Giemsa stains. The lipid hydroperoxide content was assessed by the orange xylenol spectrophotometric method.


RESULTS
Quercetin significantly reduced the infiltration index of mononuclear cell and bacterial colonization in the pyloric antrum and corpus. In the antrum of infected quercetin-treated animals, a significant diminution of neutrophil leukocyte infiltration was observed compared with the infected nonquercetin-treated animals. In the antrum, the lipid hydroperoxide concentration was significantly decreased in infected animals treated with quercetin, whereas in the corpus no significant differences were observed.


CONCLUSIONS
Our results indicate that in vivo oral quercetin administration decreases H. pylori infection in the gastric mucosa and reduces both the inflammatory response and lipid peroxidation.
González-Segovia
Rodolfo
R
Department of Microbiology, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, Ciudad Universitaria, Av. Universidad 940., C.P. 20100, Aguascalientes Ags, México.
Quintanar
J Luis
JL
Salinas
Eva
E
Ceballos-Salazar
Rebeca
R
Aviles-Jiménez
Francisco
F
Torres-López
Javier
J
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D006168:Guinea Pigs; D016481:Helicobacter Infections / Q000378:metabolism / Q000382:microbiology / Q000473:pathology*; D016480:Helicobacter pylori / Q000187:drug effects; D007249:Inflammation; D015227:Lipid Peroxidation / Q000187:drug effects*; D011794:Quercetin / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D000975:Antioxidants; D011794:Quercetin