_1704005677 20231231065437000 Rovedar Daryoushbabazadeh@gmail.com Rovedar Journal of Lab Animal Research J Lab Anim. Res 2980-9703 12 25 2023 2 6 Ahmad Asadi Ardebili https://orcid.org/0009-0003-5910-2108 Introduction: Pain is one of the primary and fundamental issues associated with various diseases that every individual will encounter throughout their lifetime. Non-steroidal anti-inflammatory drugs (NSAIDs) and opioids are commonly used for pain control, but they have significant side effects. The current study aimed to evaluate the effect of systemic administration of monoterpenes on visceral pain in an animal model. Materials and methods: In this experimental study, 30 male albino rats weighing approximately 21 to 25 grams were used. The rats were randomly divided into three groups of 10. The control group did not receive any drug, while the first treatment group received d-limonene orally at a dose of 10 milligrams per kilogram, known as a monoterpene compound. The second treatment group received tramadol orally at a dose of 20 milligrams per kilogram. To assess the effects of monoterpenes on colonic pain, intraperitoneal injection of 6% acetic acid (4 mg/kg) was used, and the number of reflex contractions, which could be easily distinguishable and lasted for several seconds, was observed and counted for 90 minutes. Data were collected and averaged every 5 minutes and then subjected to initial statistical analysis. Results: A significant difference in terms of visceral pain was observed between these two groups. The rats in the first treatment group that received limonene perceived significantly less visceral pain than those in the control group. The findings indicated a significant difference between treatment groups 1 and 2, meaning that tramadol creates a greater analgesic effect. Conclusion: This finding suggests that monoterpenes cannot produce the same level of analgesic effects on visceral pain as opioids. 12 25 2023 100 103 https://creativecommons.org/licenses/by/4.0 10.58803/jlar.v2i6.35 https://jlar.rovedar.com/index.php/JLAR/article/view/35 https://jlar.rovedar.com/index.php/JLAR/article/download/35/75 https://jlar.rovedar.com/index.php/JLAR/article/download/35/75 10.1016/S0140-6736(21)00392-5 Dydyk A, Sizemore D, Trachsel L, Dulebohn S, Porter B. Tennessee controlled substance prescribing for acute and chronic pain. StatPearls. 2023. Available at: https://www.ncbi.nlm.nih.gov/books/NBK567756/ 10.2217/pme-2018-0116 10.1016/j.bcp.2020.114147 10.2174/1381612825666190717152226 Doneddu PE, Pensato U, Iorfida A, Alberti C, Nobile-Orazio E, Fabbri A, et al. Neuropathic Pain in the Emergency Setting: Diagnosis 10.3390/jcm12186028 10.1016/S0140-6736(21)00393-7 10.1016/j.bja.2019.03.023 10.1038/s41583-021-00536-7 10.2147/JPR.S223893 10.3390/molecules28207089 10.58803/jlar.v1i1.8 10.17582/journal.pjar/2021/34.2.381.392 Sharmeen JB, Mahomoodally FM, Zengin G, Maggi F. Essential oils as natural sources of fragrance compounds for cosmetics 10.3390/molecules26030666 10.3390/su11195483 10.1016/B978-0-12-824109-7.00001-7 10.5530/pres.14.2.15 10.5958/2349-2988.2020.00049.2 10.1002/ptr.7697 10.3390/ijms21197078 10.1016/j.microc.2022.107470 10.2174/1381612826666200320130443 10.1038/s41598-020-64032-1 10.1111/jfbc.13566 Soulimani R, Bouayed J, Joshi RK. Limonene: natural monoterpene volatile compounds of potential therapeutic interest. Am J Essent Oils Nat Prod. 2019; 7(4): 1-10. Available at: https://www.essencejournal. com/pdf/2019/vol7issue4/PartA/7-4-2-526.pdf 10.14814/phy2.15194 10.1177/1744806919866529 10.1016/j.drudis.2020.09.036 10.22270/jddt.v12i3-S.5502 10.3390/futurepharmacol3010009