Biochemical and Histopathological Evidence for Beneficial Effects of Pelargonium graveolens Essential Oil on the Rat Model of Inflammatory Bowel Disease

Background and objectives: Pelargonium graveolens L'Hér. is an essential oil bearing plant used in traditional medicine of Iran for the treatment of inflammatory disease and pain, anxiety, sadness and also for the relief of gastrointestinal symptoms. Its pharmaceutical product is presently used in Iran for the treatment of depression disorders. Since colitis is a brain-gut interactive disorder, the authors were prompted to investigate the preventive effect of P. graveolens essential oil product (Deproherb®) to control the induced inflammatory bowel disease (IBD) in rats. Methods: Experimentally ulcerative colitis was induced by acetic acid in animals pretreated with three different doses of Deproherb® (100, 200 and 400 mg/kg, p.o.) for five consecutive days. Anti-inflammatory effects of Deproherb® were compared with orally administrated sulfasalazine (4 mg/kg). Biochemical [Myeloperoxidase (MPO) activity] and macroscopic and microscopic examinations of the colon was performed. Deproherb® was also analyzed by GC and GC/MS in order to identify the potentially responsible compounds for observed property. Results: The obtained results indicated that the activity of MPO increased in acetic acid-treated groups, while it was recovered by pretreatment with Deproherb® (100-400 mg/kg) and sulfasalazine. All doses of Deproherb® and sulfasalazine-treated groups showed significant lower score values of macroscopic and microscopic characters when compared to the acetic acid-treated group. It was concluded that Deproherb® inhibited the acetic acid toxic reactions in the rat bowel. Conclusions: The present study proved the anti-inflammatory potential of Deproherb® Oral Drop, in the experimentally induced colitis. Proper clinical investigations are suggested to confirm the observed activities in human.