Lorestan University of Medical Sciences Herbal Medicines Journal 2538-2144 2 2 2017 05 01 The Suppression of Adjuvant-induced Inflammation and the Inhibition of the Serum and Tissue IL-17, TNF-α and IL-1β levels by Thymol and Carvacrol 51 59 221556 10.22087/hmj.v0i0.613 EN Nasser Gholijani 1Autoimmune Disease Research Center, Shiraz University of Medical Sciences, Shiraz, Iran Zahra Amirghofran 1Autoimmune Disease Research Center, Shiraz University of Medical Sciences, Shiraz, Iran 2Department of Immunology and Medicinal and Natural Products Chemistry Research Center, Shiraz University of Medical Sciences, Shiraz, Iran Journal Article 2025 05 24 Background and Aim: Thymol and carvacrol are two important components of thyme that have multiple medicinal uses. This study investigates the in vivo effects of these natural products on adjuvant-induced inflammation and secretion of interleukin (IL)-17 and key inflammatory cytokines in rats.Materials and Methods: We injected complete Freund’s adjuvant (CFA) into the hind paws of rats in order to induce inflammation. Each of the CFA-treated rat groups received gavages of thymol, carvacrol, or vehicle (CFA-only group). Rats’ paws and ankle edema were measured and then we were able to determine an inflammatory score based on the results. After 72 h of inflammation induction, sera were collected and subsequently inflamed tissue extracts were prepared for cytokine assay by ELISA.Results: Both components significantly decreased paw edema in rats (p<0.01). Thymol decreased ankle edema to 61.6% of edema in CFA-only rats (p<0.001). We observed a decreased inflammatory score in the thymol and carvacrol-treated rats. The evaluation of the tissue and serum inflammatory cytokine levels showed that both components decreased tumor necrosis factor (TNF)-α levels (p<0.05). Thymol and carvacrol reduced interleukin (IL)-1β serum and tissue levels, respectively. These components reduced tissue levels of IL-17 from 148.4±13.4pg/ml in CFA-only rats to 90.1±18.9pg/ml (thymol) and 82.3±9.2pg/ml (carvacrol). Both components decreased serum IL-17 levels in rats (p<0.05). In comparison, the anti-inflammatory drug, indomethacin, reduced the inflammatory score and decreased tissue TNF-α and IL-1β levels but did not affect IL-17 production.Conclusion: Carvacrol and thymol could relieve inflammation symptoms possibly by downregulating serum and tissue IL-17 expression in addition to key pro-inflammatory cytokines, TNFα and IL-1β. https://hmj.lums.ac.ir/article_221556_2183845686b559c7a166933746a3a41b.pdf