ABSTRACTÂ
The role of free radicals can be observed in the inflammatory process which is a complex process that results to various diseases. Inflammation is majorly divided into acute and chronic inflammation depending on the various inflammatory processes and cellular mechanisms. SOD constitutes a crucial antioxidant defense against oxidative stress in the body, the enzyme acts as a good therapeutic agent against reactive oxygen species-mediated diseases. The auto-oxidation is dependent on the presence of superoxide anions (O2-). SOD inhibits this auto-oxidation by catalyzing the breakdown of superoxide anions. Hence, the degree of inhibition is a measure of SOD activity. Anti-inflammatory, immuno-modulatory and anti-oxidant properties of Moringa oleifera suggest that it might have promising effects on colitis. In this study, the effect of Moringa oleifera leaves extract on superoxide dismutase (SOD) activity of acetic acid-induced colitis rats was investigated. The experiment was divided into two phases, which are; acute toxicity (phase one) and sub chronic toxicity (phase two). Phase one of the study was conducted to know the appropriate oral dosage of Moringa oleifera leaves extract to use for the treatment of acetic acid induced colitis in the second phase. In phase one, a total of 16 wistar albino rats were used and they were divided in fourgroups (A,B,C and D) based on their average weight. Group A which was the control group received oral administration of distilled water (0.5 ml/kg) for seven days, group B received oral administration of Moringa oleifera leaves extract ( 150 mg/kg/day) for seven days, group C received oral administration of Moringa oleifera leaves extract (300 mg/kg/day) for seven days, and group D received oral treatment of Moringa oleifera leaves extract (500 mg/kg/day) for seven days as well. After fasting for 24 hours, the rats were sacrificed and the liver, colon and kidneys were extracted and isolated in ice for biochemical analyses, and some in formalin for histopathological assessment. The blood was also analyzed for liver function test. On completion of the various analyses on the samples, a dosage of 150 mg/kg/day of Moringa oleifera leaves extract was taken as the appropriate dose for use in the next phase of the study due to its mild effects on the rats. The experimental design of phase 2 involved the division of 12 male Wistar albino rats based on their weight. The rats were grouped in 3and each group had a total of 4 rats (group A, B and C). Group A (control group) received oral administration of distilled water (0.5ml/kg) for seven days. Group B received oral administration of Moringa oleifera leaves extract (150 mg/kg/day) for seven days, and then group C received oral administration of distilled water (0.5ml/kg) for seven days. On day 8, colitis was induced by a extract single intrarectal administration of 0.5ml of acetic acid (4% v/v) in the rats. Distilled water and extract administration continued for an additional 4 days making the period of study of this phase a total of 11 days. Rats were sacrificed on day 12 and the kidneys, colon and liver were collected for antioxidant enzymes (SOD) activity assessment. The results obtained from this study revealed a depletion in SOD activity in the organs(colon, liver and kidneys) of the rats induced with acetic acid compared to the normal control, whereas, there was an observation of significant increase in the SOD activity in the organs of the groups treated with Moringa oleifera leaves extract compared to the negative control. This increase in SOD activity in the acetic acid-induced rats upon treatment with Moringa oleifera leaves extract indicates that Moringa oleifera leaves possess antioxidant and anti-inflammatory properties and thus, can help to reduce inflammation.
