Effects of hydro-ethanolic extract of leaves of Maesa lanceolata (Mursinaceae) on acetic acid-induced ulcerative colitis in rats.

Ulcerative colitis is a form of inflammatory bowel disease that is characterized by acute and chronic inflammation. The aim of this work was to evaluate the efficacy of hydroethanolic extract of Maesa lanceolata leaves on acetic acid-induced colitis in rats. Colitis was induced by rectal administration of 1 mL of acetic acid (4%) in 25 male rats except the normal control group which received distilled water after 18 h of fasting followed by Ketamine (50 mg/kg)/Valium (10 mg/kg) anesthesia. Five hours later, the normal control and the negative control received distilled water, the positive control received prednisolone (5 mg/kg) and the three test groups received extract at 100, 200 and 400 mg/kg bw for eight days. During treatment, rectal temperature, the number and quality of the stools, and changes in body weight were assessed. At the end of the treatment, the animals were sacrificed, blood, colon, liver and spleen were collected for evaluation of hematological, inflammatory, antioxidant and histological parameters. Rectal temperature and the number of diarrheal, mucus and bloody stools were significantly reduced (P < 0.01) during treatment in the test and positive control groups with an increase in body weight change. The extract significantly (P < 0.01) reduced myeloperoxidase, TNF-α, interleukin 6, NO and MDA levels and significantly (P < 0.01) increased SOD levels, of GSH and catalase activity in the colon and blood. This extract also increased (P < 0.01) levels of red blood cells, hemoglobin, hematocrit, total white blood cells and blood platelets, prevented leukocyte infiltration in the liver and colon.