Anxiolytic and anti-colitis effects of Moringa oleifera leaf-aqueous extract on acetic acid-induced colon inflammation in rat

Abstract

Moringa oleifera decoction is believed to alleviate gastrointestinal tract diseases. This study investigated antioxidant and anxiolytic activities of its leaves aqueous extract on acetic acid-induced colitis in rats. Rats (36) were randomly divided into six groups and received (20 days) distilled water, 10 mL/kg; Moringa oleifera leaf-aqueous extract (25, 50, and 100 mg/kg) or Loperamide (5 mg/kg). On days 1, 8, 17, and 20, behavioral parameters were evaluated. Colitis was induced (day 15, except in normal group) through acetic acid (4%, 1 mL) intra-rectal administration. After sacrifice (day 21), lesion number, weight/length ratio of the colon were recorded. Oxidative stress biomarkers were evaluated. On day 20, Moringa oleifera (100 mg/kg) reduced the number of head dipping and the duration in opened arms, respectively 2.00 ± 0.37 and 5.00 ± 0.37 s against 14.50 ± 0.72 and 2.17 ± 0.48 s in the control. It decreased colon weight/length ratio: 112.29 ± 9.46 against 185.93 ± 5.28 mg/cm in the control; malondialdehyde level (P < 0.01) and nitric oxide concentration (P < 0.001), in the brain: respectively 25.60 ± 0.60 and 36.34 ± 1.19 against 34.00 ± 0.33 and 46.17 ± 3.25 µmol/mg of tissue in the control. In the serum, the extract (50 mg/kg) significantly (P < 0.05) increased the catalase activity (0.10 ± 0.00 against 0.03 ± 0.00 µmol/mg of protein in the negative control group). At 100 mg/kg, it increased (P < 0.001) reduced glutathione concentration to 5.07 ± 0.31 against 3.26 ± 0.08 µmol/mg of protein in the negative control group. The improvement on colitis pathophysiology, the antioxidant and the anxiolytic effects noted therefore suggest that Moringa oleifera can be a potential source of drugs alleviating anxiety and oxidative stress associated to ulcerative colitis.

Keywords

• Moringa oleifera
• Acetic acid
• Ulcerative colitis
• Oxidative stress
• Anxiety