Quercetin prevents small intestinal damage and enhances intestinal recovery during methotrexate-induced intestinal mucositis of rats

Background: Gastrointestinal mucositis occurs as a consequence of cytotoxic treatment. Quercetin (QCT) is a bioflavonoid that exerts significant antioxidant activity and anti-inflammatory as well as anti-malignancy properties. Objective: To evaluate the effects of oral QCT consumption in preventing intestinal mucosal damage and stimulating intestinal recovery following methotrexate (MTX)-induced intestinal damage in a rat model. Design: Male Sprague-Dawley rats were divided into four groups: Control Group A (CONTR) - rats were treated with 2 cc of saline given by gavage for 6 days. Group B (CONTR-QCT) - rats were treated with QCT (100 mg/kg in 2 ml saline) given by gavage 3 days before and 3 days after intraperitoneal (IP) injection of saline. Group C (MTX) - rats were injected a single dose (25 mg/kg) of MTX IP. Group D (MTX-QCT) rats were treated with QCT (similar to Group B) 3 days before and 3 days after IP MTX injection. Intestinal mucosal parameters (bowel and mucosal weight, mucosal DNA and protein content, and villus height and crypt depth), enterocytes proliferation, and enterocyte apoptosis degree were investigated at sacrifice on the 4th day after MTX or saline injection. Results: Administration of QCT to MTX-treated rats resulted in: (1) significant decrease in intestinal injury score, (2) significant increase in intestinal and mucosal weight in jejunum and ileum, (3) increase on the protein content of the ileum, (4) increase in the villus height in the ileum, (5) increase of crypt depth of jejunum and ileum, and (6) increase in cell proliferation in the jejunum and ileum compared to MTX-nontreated group. Conclusions: Administration of QCT prevents intestinal damage and improves intestinal recovery following MTX-induced intestinal damage in a rat. We surmise that the effect of QCT is based on induction of cell proliferation in the crypt rather than inhibition of apoptosis.