Abstract
Background/Aims: Ulcerative colitis (UC) is a chronic inflammatory disorder with indefinite etiology; however, environmental, genetic, immune factors and microbial agents could be implicated in its pathogenesis. UC treatment is lifelong, therefore; the potential side effects and cost of the therapy are significant. Yarrow is a promising medicinal plant with the ability to treat many disorders, owing to its bioactive compounds especially the essential oil. The main aim of this research was to investigate the therapeutic effect of the yarrow oil on colitis including the involved mechanism of action. Methods: In 21-female C57BL/6 mice were divided into 3 groups; control group, colitis model group, and oil-treated group. Groups 2 and 3 received 5% dextran sulfate sodium (DSS) in drinking water for 9 days, and concomitantly, only group 3 was given 100 mg/kg yarrow oil. Mice were examined for their body weight, stool consistency and bleeding, and the disease activity indexes were calculated. Results: Oral administration of yarrow oil markedly repressed the severity of UC via the reduction of the inflammatory signs and restoring colon length. The oil was able to down-regulate nuclear factor kappa light chain enhancer of activated B cells (NF-kappa B), up-regulate peroxisome proliferator-activated receptor gamma (PPAR-gamma), and enhance transforming growth factor-beta expression. The oil normalized the tumor necrosis factor-a expression, restored the normal serum level of interleukin-10 (IL-10) and reduced the serum level of IL-6. Conclusions: Yarrow oil mitigated UC symptoms and regulated the inflammatory cytokines secretion via regulation of NF-kappa B and PPAR-gamma pathways in the mice model, however, this recommendation requires further investigations using clinical studies to confirm the use of the oil on humans.