Basic Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 14, 2020; 26(34): 5118-5129
Published online Sep 14, 2020. doi: 10.3748/wjg.v26.i34.5118
Acupuncture improved lipid metabolism by regulating intestinal absorption in mice
Jia Han, Xin Guo, Xiang-Jin Meng, Jing Zhang, Reimon Yamaguchi, Yoshiharu Motoo, Sohsuke Yamada
Jia Han, Xin Guo, Xiang-Jin Meng, Jing Zhang, Sohsuke Yamada, Department of Pathology and Laboratory Medicine, Kanazawa Medical University, Ishikawa 920-0293, Japan
Jia Han, Yoshiharu Motoo, Department of Oncology, Kanazawa Medical University, Ishikawa 920-0293, Japan
Xin Guo, Sohsuke Yamada, Department of Pathology, Kanazawa Medical University Hospital, Ishikawa 920-0293, Japan
Reimon Yamaguchi, Department of Dermatology, Kanazawa Medical University, Ishikawa 920-0293, Japan
Author contributions: Han J, Guo X and Yamada S conceptualized and designed the experiments; Han J, Guo X, Meng XJ, Zhang J and Yamaguchi R carried out the experiments; Han J, Guo X and Zhang J analyzed the data; Han J and Guo X wrote the manuscript; Guo X, Yamada S and Motoo Y edited the manuscript.
Supported by the Grants-in-Aid for Scientific Research, No. 19K16783; the Ministry of Education, Culture, Sports, Science and Technology, Tokyo, Japan, No. 20K07454 and No. 20K17363; Grant for Promoted Research from Kanazawa Medical University, No. S2018-6.
Institutional review board statement: The study was reviewed and approved by the Institutional Review Board at Kanazawa Medical University.
Institutional animal care and use committee statement: All animal experiments conformed to the internationally accepted principles for the care and use of laboratory animals.
Conflict-of-interest statement: The authors declare no conflicts of interest in association with the present study.
Data sharing statement: No additional data are available.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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/
Corresponding author: Xin Guo, PhD, Doctor, Department of Pathology and Laboratory Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Kahoku, Ishikawa 920-0293, Japan. tianqi11211216@yahoo.co.jp
Received: May 19, 2020
Peer-review started: May 19, 2020
First decision: June 20, 2020
Revised: June 30, 2020
Accepted: August 14, 2020
Article in press: August 14, 2020
Published online: September 14, 2020
Processing time: 113 Days and 1.6 Hours
Abstract
BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), in which abnormal lipid metabolism plays an important role in disease progression, has become a pandemic. Abnormal lipid metabolism, for example an increased fat intake, has been thought to be an initial factor leading to NAFLD. The small intestine is the main site of dietary lipid absorption. A number of clinical trials have shown that acupuncture has positive effects in the regulation of lipid metabolism, which is closely associated with the progression of NAFLD. We therefore hypothesized that, acupuncture can improve the conditions of NAFLD by regulating intestinal absorption of lipid.

AIM

To study the role of acupuncture treatment in the improvement of metabolic syndrome secondary to NAFLD by mouse model.

METHODS

8-wk-old male C57BL/6J mice were fed a methionine- and choline-deficient diet for 3 wk. Then, all mice were separated randomly into acupoints group (AG) or non-acupoints group (NG) with high fat diet feeding. Needling treatment was performed at Zu san li, Guan yuan and Yong quan acupoints as acupuncture treatment to AG mice while non-acupoints place to NG mice. Finally, mice were anesthetized with an injection of ketamine-medetomidine and euthanized by exsanguination.

RESULTS

An apparent improvement of obesity was found in AG mice after acupuncture treatment. In AG mice, the body weight was much lower (22.6 ± 1.2 g vs 28.1 ± 1.0 g, P < 0.005) in comparison to NG mice. The length of small intestine in AG mice was significantly shorter (26.7 ± 2.3 cm vs 32.7 ± 2.7 cm, P < 0.005). A large amount of chyme was observed in the lumen of the AG small intestine. The expression of microsomal triglyceride transfer protein, apolipoprotein B and apolipoprotein C2 was downregulated. Triacylglycerols (TGs), total cholesterol and nonesterified fatty acid (NEFA) levels of the small intestinal tissue were significantly higher in AG mice, but the serum TGs and NEFA levels were reduced in AG mice.

CONCLUSION

These results indicate that acupuncture at Zu san li, Guan yuan and Yong quan suppressed lipid absorption by downregulating the expression of apolipoproteins in the small intestine.

Keywords: Acupuncture; Non-alcoholic fatty liver disease; Small intestine; Lipid metabolism; Apolipoproteins

Core Tip: In the present study, our experimental data showed that acupuncture treatment suppressed high-fat-induced body weight gain, reduced the accumulation of intra-abdominal fat, inhibited lipid absorption in the small intestine and downregulated the blood lipid level in mice with non-alcoholic fatty liver disease, suggesting that acupuncture potentially had variable beneficial effects in improving the lipid metabolism in the presence of abnormal liver metabolism. Furthermore, we also found more fat deposition in the intestinal epithelium with the decreased expression of some intestinal apolipoproteins in acupuncture-treated mice, suggesting that acupuncture may suppress lipid absorption by downregulating the expression of apolipoproteins in the small intestine.