Linalyl acetate restores colon contractility and blood pressure in repeatedly stressed-ulcerative colitis rats

BACKGROUND: Ulcerative colitis (UC) is related to stress, but few studies have evaluated the influence of stress on factors affecting colon contractility in rats with UC. Also, there have been no studies investigating beneficial effects of linalyl acetate (LA), the major component of lavender essential oil, in repeatedly stressed-ulcerative colitis rats. Therefore, we investigated the differences in factors affecting colon contractility of UC rats with or without repeated restraint stress (RRS) and the effects of LA on these parameters in repeatedly stressed-UC rats. METHODS: Rats were assigned to following groups: control, RRS, UC, RRS+UC, and RRS+UC treated with LA or sulfasalazine. To induce UC, rats were administered 2% dextran sodium sulfate (DSS) water on days 1–5, followed by tap water on days 6–15 and DSS water on days 16–20. RRS was induced by immobilizing rats for 2 hr/day on days 1–20. LA or sulfasalazine were daily administered on days 16–20. RESULTS: Disease activity index (DAI) was markedly increased in RRS+UC. Serum interleukin-6 levels and acetylcholine-induced colon contraction were higher in RRS+UC than in control, RRS and UC. Colon nitrite levels also significantly increased in RRS+UC compared to the control and RRS. Blood pressure (BP) was higher in RRS+UC than in the control and UC. Both LA and sulfasalazine was effective in decreasing DAI, colon nitrite levels, acetylcholine-induced colon contraction in RRS+UC. Sulfasalazine significantly reduced serum IL-6 levels in RRS+UC with decreasing tendency in RRS+UC treated by LA. Only LA significantly reduced BP in RRS+UC. CONCLUSIONS: Our findings emphasize the importance of stress management in UC patients. Also, LA may be beneficially used in repeatedly stressed-UC patients with high BP.