Protective effect of Melissa officinalis against acetic acid-induced ulcerative colitis in rat models: an experimental study.

Background: Inflammation and oxidative activities within the gut play major roles in the pathogenesis of ulcerative colitis (UC). We aimed to determine the effect of Melissa officinalis, an antioxidant and anti-inflammatory agent, on the colon histological characteristics in acetic acid (AA)-induced UC in rat models. Methods: Thirty-six male rats with AA-induced colitis were divided into 5 groups: no treatment (AA); daily treatment with 300 mg/kg Melissa officinalis orally (MO) and rectally (MR); and 100 mg/kg mesalamine orally (AO) and rectally (AR). Macroscopic and histopathological evaluation of the colon, along with a biochemical laboratory evaluation, were performed 10 days after UC induction. Results: All treatment groups demonstrated lower macroscopic grading scores compared to the AA group. After treatment with MO, 42.9% of cases demonstrated no macroscopic changes, while 14.3% demonstrated only mucosal erythema. In the MR group 28.6% of rats had no changes in their mucosal lining and 28.6% had only mucosal erythema. Following histopathological evaluation, the AO group had lower scores regarding the severity of ulcer, inflammation, destruction, crypt abscess, and disorganization compared to the MO group. (P=0.02) The MR group demonstrated lower microscopic scores compared to the MO group, and also lower macroscopic scores compared to the AR group, although not significantly (P>0.05). Conclusions: Both oral and topical administration of Melissa officinalis have satisfactory healing properties compared to mesalamine, with topical route having better results. Therefore, further studies are needed to establish the benefit of Melissa officinalis administration (both orally and topically) within a UC treatment protocol.

Evaluation of oral and topical bovine colostrum compared to mesalamine in the treatment of animal model of acetic acid-induced ulcerative colitis.

Background: Oxidative activity and inflammatory responses have been shown to play a pivotal role in the pathogenesis of ulcerative colitis (UC). Colostrum is a natural product with anti-inflammatory and antioxidative properties. Methods: UC was induced in 37 Sprague Dawley rats by administration of a 2 mL enema of 3% acetic acid (AA). The control groups received no treatment during the study, while the experimental groups received either oral or rectal administration of 100 mg/kg 5-aminosalicylic acid, or oral or rectal administration of 300 mg/kg of colostrum. Histopathological and serological analyses were performed 7 days following treatment. Results: A significant decrease in weight was seen in all rats except for the test groups receiving colostrum (P<0.001). After treatment, the level of superoxide dismutase increased more significantly in the test groups that received colostrum (P<0.05). All test groups had a reduction in C-reactive protein and white blood cell levels. The colostrum test groups also showed a decrease in inflammation rate, ulceration, destruction, disorganization, and crypt abscess of the colonic mucosa. Conclusions: The findings of this study show that the administration of colostrum can improve the pathological changes of the intestinal mucosa, as well as inflammatory responses, in animal models of UC. Further studies at both preclinical and clinical levels are suggested to confirm these findings.