The Antioxidant Activity and the Anti-inflammatory Effect of Citrus sinensis L. Fruit on Intestinal Inflammation Induced by Hyperhomocysteinemia in Mice

Abstract Hyperhomocysteinemia is considered to be one of the risk factors for inflammatory bowel disease (IBD), it is a chronic, relapsing, and remittent inflammatory disease of the gastrointestinal tract. Citrus sinensis L. has been used traditionally to treat bowel disorders. The present study aims to quantify the phenolic and flavonoid contents of the Citrus sinensis L. fruit (ORF) extract and to evaluate in vitro the antioxidant activity and the anti-inflammatory effect of ORF in vivo on intestinal inflammation induced by hyperhomocysteinemia. The total phenolic and flavonoid contents of the extract were determinated using the spectrophotometric method and the evaluation of antioxidant activity was performed by four methods: DPPH, ABTS, CUPRAC, and reducing power. The inflammatory marker (plasma homocysteine), the reduced glutathione (GSH) content in the liver tissue were measured and the histological sections of the intestines of the mice used were examined to assess the anti-inflammatory activity of ORF. The results of this study showed that the ethanolic extract of ORF possessed high phenolic content and exhibited good antioxidant activity. The use of ORF powder in the in vivo study showed an increase in GSH levels, a decrease in plasma homocysteine levels, and a restoration of the integrity of the intestinal epithelium. Keywords: Hyperhomocysteinemia, Intestinal Inflammation, Citrus sinensis L. fruit, Antioxidant activity, Anti-inflammatory