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©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
Curcumin improves regulatory T cells in gut-associated lymphoid tissue of colitis mice
Hai-Mei Zhao, Rong Xu, Xiao-Ying Huang, Shao-Min Cheng, Min-Fang Huang, Hai-Yang Yue, Xin Wang, Yong Zou, Ai-Ping Lu, Duan-Yong Liu
Hai-Mei Zhao, Shao-Min Cheng, School of Basic Medical Sciences, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, Jiangxi Province, China
Rong Xu, Min-Fang Huang, Hai-Yang Yue, Xin Wang, Yong Zou, Department of Postgraduate, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, Jiangxi Province, China
Xiao-Ying Huang, Key Laboratory of Modern Preparation of Traditional Chinese Medicine, Ministry of Education, Jiangxi university of Traditional Chinese Medicine, Nanchang 330004, Jiangxi Province, China
Ai-Ping Lu, School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China
Duan-Yong Liu, Science and Technology College, Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, Jiangxi Province, China
Author contributions: Zhao HM is primary author of the manuscript, and designed, performed the research; Zhao HM, Huang XY and Lu AP contributed to analysis of data, as well as writing and reviewing the final manuscript; Xu R, Huang MF, Yue HY, Wang X and Zou Y performed the research; and Liu DY was involved in project conception/design and data analysis, as well as writing and reviewing the final manuscript.
Supported by Project of National Natural Science Foundation of China, No. 81260595 and No.81460679; and Chinese Scholarship Council and Jiangxi Province as visiting scholar, No. 201408360106 and No. 201408360110; and Project of Jiangxi University of Traditional Chinese Medicine, No. JZYC15S13.
Institutional review board statement: All routine colonic biopsy specimens and gut-associated lymphoid tissue samples from the mice were taken after ethical permission was obtained for participation in the study.
Institutional animal care and use committee statement: The experimental protocols (IACUC protocol number: JZ2015-016) were approved by Institutional Animal Care and Use Committee of Jiangxi University of Traditional Chinese Medicine.
Conflict-of-interest statement: All authors have declared that there is no conflict of interests.
Data sharing statement: No additional unpublished data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Duan-Yong Liu, Associate Professor, Science and Technology College, Jiangxi University of Traditional Chinese Medicine, 819 Xingwan Road, Nanchang 330004, Jiangxi Province, China. liuduanyong@163.com
Telephone: +86-791-86588407 Fax: +86-791-86588407
Received: February 27, 2016
Peer-review started: February 28, 2016
First decision: March 21, 2016
Revised: March 29, 2016
Accepted: April 15, 2016
Article in press: April 15, 2016
Published online: June 21, 2016
AIM: To explore the probable pathway by which curcumin (Cur) regulates the function of Treg cells by observing the expression of costimulatory molecules of dendritic cells (DCs).
METHODS: Experimental colitis was induced by administering 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)/ethanol solution. Forty male C57BL/6 mice were randomly divided into four groups: normal, TNBS + Cur, TNBS + mesalazine (Mes) and TNBS groups. The mice in the TNBS + Cur and TNBS +Mes groups were treated with Cur and Mes, respectively, while those in the TNBS group were treated with physiological saline for 7 d. After treatment, the curative effect of Cur was evaluated by colonic weight, colonic length, weight index of the colon, and histological observation and score. The levels of CD4+CD25+Foxp3+ T cells (Treg cells) and costimulatory molecules of DCs were measured by flow cytometry. Also, related cytokines were analyzed by enzyme-linked immunosorbent assay.
RESULTS: Cur alleviated inflammatory injury of the colonic mucosa, decreased colonic weigh and histological score, and restored colonic length. The number of Treg cells was increased, while the secretion of TNF-α, IL-2, IL-6, IL-12 p40, IL-17 and IL-21 and the expression of costimulatory molecules (CD205, CD54 [ICAM-1], TLR4, CD252[OX40 L], CD256 [RANK] and CD254 [RANK L]) of DCs were notably inhibited in colitis mice treated with Cur.
CONCLUSION: Cur potentially modulates activation of DCs to enhance the suppressive functions of Treg cells and promote the recovery of damaged colonic mucosa in inflammatory bowel disease.
Core tip: The low level of regulatory T (Treg) cells plays an important role in pathogenic process of inflammatory bowel disease (IBD). In our and other previous studies, curcumin (Cur) can effectively attenuate inflammation in humans and animals with colitis. However, whether Cur can improve the level of Treg cells and the pathway by which Cur regulates Treg cells are unclear. In the present study, we have shown that Cur potentially modulates activation of dendritic cells to enhance the suppressive functions of Treg cells and promote the recovery of damaged colonic mucosa in IBD.
