Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Thymol exerts anti-inflammatory effect in dextran sulfate sodium-induced experimental murine colitis

De-Ming Liu¹, Chun-Yan Zhou², Xian-Li Meng¹, Ping Wang¹, Wen Li¹

¹School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 610037; ²School of Nursing, North Sichuan Medical College, Nanchong 637300, China.

For correspondence:- Wen Li Email: wenlitcm@163.com Tel:+862887786551

Accepted: 22 August 2018 Published: 30 September 2018

Citation: Liu D, Zhou C, Meng X, Wang P, Li W. Thymol exerts anti-inflammatory effect in dextran sulfate sodium-induced experimental murine colitis. Trop J Pharm Res 2018; 17(9):1803-1810 doi: 10.4314/tjpr.v17i9.18

© 2018 The authors.
This is an Open Access article that uses a funding model which does not charge readers or their institutions for access and distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) and the Budapest Open Access Initiative (http://www.budapestopenaccessinitiative.org/read), which permit unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited..

Abstract

Purpose: To investigate the effect of thymol on dextran sulfate sodium (DSS)-induced experimental colitis in mice.

Methods: Colitis in mice was induced by drinking water with 2.5 % (w/v) DSS. The levels of myeloperoxidase (MPO), malondialdehyde (MDA), glutathione (GSH) and superoxide (SOD) in colonic tissues were determined using commercial kits. Histological changes were evaluated by hematoxylin and eosin staining. The production of nitric oxide (NO) was measured by Griess assay. The levels of pro-inflammatory cytokines including TNF-α, IL-1β and IL-6 were assessed by quantitative PCR and ELISA kits. Nuclear factor-kappaB (NF-κB) pathway activation was determined by Western blot.

Results: Thymol markedly reduced disease activity index (DAI) scores, and recovered the colon length. Histological damage and MPO levels in the colonic tissues were markedly inhibited (p < 0.05) by thymol, which also reduced mRNA expressions of TNF-α, IL-1β and IL-6 in the colon. In addition, it down-regulated MDA level but elevated GSH and SOD levels. Moreover, in vitro data showed that thymol significantly inhibited (p < 0.05) lipopolysaccharide-induced secretion of NO, TNF-α, IL-1β and IL-6 in macrophages, and suppressed (p < 0.05) the activation of NF-κB pathway.

Conclusion: Thymol attenuates experimental colitis by down-regulating the activation of NF-κB pathway. Therefore, thymol is a potential candidate drug for the management of ulcerative colitis.

Keywords: Thymol, Ulcerative colitis, Dextran sulfate sodium, Macrophages, Nuclear factor-kappaB