Evaluation of Active Compounds of Sideritis Trojana Ethanolic Extract and Their Protective Effects in Rats with Acetic Acid-Induced Ulcerative Colitis

Objective: In this study, we aimed to examine the effects of Sideritis trojana (ST) ethanolic extract in acetic acid (AA)-induced rat model of colitis. Design: Firstly, anti-DPPH and anti-ABTS free radical scavenging, anti-5-lipoxygenase (LOX) activities, and total secondary metabolite quantities of ST extract were measured. Secondly, while the sham control group (C) and 5% AA-infused (intrarectally) colitis group were treated with saline, other colitis groups were treated with sulfasalazine (100 mg/kg/orally) or ST (200 mg/kg/orally). At the end of the 72-h colonic myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA), TNF-α, IL-1β, IL-17, IL-10 levels, and macroscopic and histopathologic evaluations were done. Results: Results: ST had high total phenolic, total flavonoid, and total triterpene content, while it showed high antioxidant activity against ABTS or DPPH radicals and anti-5-LOX enzyme activity. Increased macroscopic and microscopic scores in the colitis group were reduced by treatments. TNF-α, IL-1β and IL-17 levels were increased in the colitis group compared with the control group, while these levels were decreased in the ST and sulfasalazine groups. Moreover, increased MPO, MDA and decreased GSH levels in the colitis group were reversed by ST and sulfasalazine treatments. Conclusion: ST extract alleviates ulcerative colitis, attributed to its rich composition of total flavonoids, phenolics, and triterpenes, as well as its anti-5-lipoxygenase (5-LOX) activity and potent free radical scavenging properties.