¹Mugla Sıtkı Koçman University, Faculty of Milas Veterinary Medicine, Department of Animal Nutrition and Nutritional Disease, TR-48200 Muğla - TÜRKİYE
²Afyon Kocatepe University, Faculty of Veterinary Medicine, Department of Anatomy, TR-03200 Afyonkarahisar - TÜRKİYE
³Mugla Sıtkı Koçman University, Faculty of Milas Veterinary Medicine, Department of Physiology, TR-48200 Muğla - TÜRKİYE DOI : 10.9775/kvfd.2023.29460 The aim of this study was to investigate the effects of peppermint (Mentha piperita L.) essential oil on duodenal and colonic contractions of broilers in vitro. For this purpose, 10 broiler intestines (42 days old) obtained from a slaughterhouse were brought to the laboratories by immersed in Krebs solution (NaCl, 118 mmol/L; KCl, 4.7 mmol/L; CaCl2, 2.5 mmol/L; MgSO4, 1 mmol/L; KH2PO4, 1 mmol/L; glucose, 11 mmol/L; NaHCO3, 25 mmol/L) at +4°C. Isolated duodenal and colon tissue strips were placed in a fourchannel, isolated organ bath system, where they were exposed to Krebs solution aerated with a gas mixture of 95% O2 - 5% CO2, at 39°C. The effect of peppermint essential oil (PEO) obtained by hydrodistillation method on spontaneous duodenum and colon contractions was evaluated in the concentration range of 0.1-1000 μg/mL. Subsequently, the effects of 300 and 1000 μg/mL PEO were reevaluated on acetylcholine-induced contractions after incubation with Nω-Nitro-L-arginine (L-NNA, NOS inhibitor) and Methylene Blue (MB, cGC inhibitor). It was determined that the PEO dose-dependently decreased the amplitude of spontaneous and acetylcholine-induced contractions in both isolated tissues. This relaxant effect persisted after L-NNA and MB incubations. In conclusion, PEO induced relaxation in isolated duodenum and colon intestinal smooth muscles not through the nitric oxide-sGMP pathway. Keywords : Broiler, Colon, Contraction, Duodenum, Peppermint essential oil