Basic Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 28, 2015; 21(48): 13457-13465
Published online Dec 28, 2015. doi: 10.3748/wjg.v21.i48.13457
Fenugreek lactone attenuates palmitate-induced apoptosis and dysfunction in pancreatic β-cells
Jing Gong, Hui Dong, Shu-Jun Jiang, Ding-Kun Wang, Ke Fang, De-Sen Yang, Xin Zou, Li-Jun Xu, Kai-Fu Wang, Fu-Er Lu
Jing Gong, Hui Dong, Shu-Jun Jiang, Ding-Kun Wang, Ke Fang, Xin Zou, Li-Jun Xu, Kai-Fu Wang, Fu-Er Lu, Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
De-Sen Yang, Department of Pharmacology, Hubei University of Chinese Medicine, Wuhan 430065, Hubei Province, China
Author contributions: Gong J, Dong H and Lu FE designed and wrote the article; Lu FE instructed on the whole study; Jiang SJ, Wang DK, Fang K, Yang DS, Xu LJ, Zou X and Wang KF offered proposals critically for important intellectual content; and all authors approved the final version to be published.
Supported by The National Natural Science Foundation of China, No. 81273683 and No. 81473637.
Institutional review board statement: The study was reviewed and approved by the Tongji Medical College of Huazhong University of Science and Technology Institutional Review Board.
Conflict-of-interest statement: There is no conflict of interest to disclose.
Data sharing statement: Technical appendix, statistical code, and dataset are available. Participants gave informed consent for data sharing. No additional 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: Dr. Fu-Er Lu, Institute of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1037 Jiefang Road, Wuhan 430030, Hubei Province, China. felu@tjh.tjmu.edu.cn
Telephone: +86-27-83663237 Fax: +86-27-83663237
Received: June 14, 2015
Peer-review started: June 16, 2015
First decision: July 19, 2015
Revised: August 9, 2015
Accepted: September 28, 2015
Article in press: September 30, 2015
Published online: December 28, 2015
Abstract

AIM: To investigate the effect of fenugreek lactone (FL) on palmitate (PA)-induced apoptosis and dysfunction in insulin secretion in pancreatic NIT-1 β-cells.

METHODS: Cells were cultured in the presence or absence of FL and PA (0.25 mmol/L) for 48 h. Then, lipid droplets in NIT-1 cells were observed by oil red O staining, and the intracellular triglyceride content was measured by colorimetric assay. The insulin content in the supernatant was determined using an insulin radio-immunoassay. Oxidative stress-associated parameters, including total superoxide dismutase, glutathione peroxidase and catalase activity and malondialdehyde levels in the suspensions were also examined. The expression of upstream regulators of oxidative stress, such as protein kinase C-α (PKC-α), phospho-PKC-α and P47phox, were determined by Western blot analysis and real-time PCR. In addition, apoptosis was evaluated in NIT-1 cells by flow cytometry assays and caspase-3 viability assays.

RESULTS: Our results indicated that compared to the control group, PA induced an increase in lipid accumulation and apoptosis and a decrease in insulin secretion in NIT-1 cells. Oxidative stress in NIT-1 cells was activated after 48 h of exposure to PA. However, FL reversed the above changes. These effects were accompanied by the inhibition of PKC-α, phospho-PKC-α and P47phox expression and the activation of caspase-3.

CONCLUSION: FL attenuates PA-induced apoptosis and insulin secretion dysfunction in NIT-1 pancreatic β-cells. The mechanism for this action may be associated with improvements in levels of oxidative stress.

Keywords: Fenugreek lactone, Diabetes, Oxidative stress, Insulin secretion, Apoptosis

Core tip: Fenugreek is a widely used traditional Chinese medicine that can improve hyperglycemia. The hypoglycemic active ingredients and mechanisms of fenugreek remain unclear. We studied an ingredient of fenugreek, fenugreek lactone, and our results suggest that fenugreek lactone attenuates palmitate-induced apoptosis and insulin secretion dysfunction in NIT-1 pancreatic β-cells by improving oxidative stress.