Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Conjugated linoleic acid attenuates neuropathic pain induced by sciatic nerve in mice

Qingbin Shi , Xiuying Cai, Changchun Li, Zhen Wang, Xingle Lv

Department of Encephalopathy, Zhangqiu District of Traditional Chinese Medicine Hospital, Jiâ€™nan, 250200, China;

For correspondence:- Qingbin Shi Email: shiqingbinchxw@163.com

Accepted: 30 August 2019 Published: 30 September 2019

Citation: Shi Q, Cai X, Li C, Wang Z, Lv X. Conjugated linoleic acid attenuates neuropathic pain induced by sciatic nerve in mice. Trop J Pharm Res 2019; 18(9):1895-1901 doi: 10.4314/tjpr.v18i9.16

© 2019 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: Conjugated linoleic acid (CLA) has been suggested to be necessary for human health, but there is limited research regarding its effect on neuropathic pain (NP). Here, we aim to investigate the potential effect of CLA administration on NP development and nerve recovery.

Methods: Forty mice were divided into four equal groups randomly. The mice in control group underwent a sham operation to achieve a unilateral sciatic nerve cut. Other groups were subjected to partial sciatic nerve ligation (PSNL) surgery followed by 4 weeks of CLA treatment. Behavioral tests were performed shortly before mice were sacrificed. Blood, sciatic nerve and spinal cord tissues were collected after sacrifice. Electron microscopy was performed to determine myelin thickness and calculate myelin thickness/axon diameter ratio.

Results: Mice that received daily oral CLA treatment for 4 weeks after PSNL surgery showed less mechanical and thermal allodynia than mice in PSNL surgery alone group. Behavioral tests showed that CLA treatment was associated with marked increases in both nerve conduction velocity (NCV) and force of gastrocnemius contraction. In addition, CLA reduced the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), sciatic myeloperoxidase (MPO) activity, and activating transcription factor-3 (ATF-3) expression. CLA also restored mitochondrial manganese superoxide dismutase (MnSOD) activity which was decreased in the sciatic nerves and spinal cords of the PSNL surgery group. Regeneration of myelins and axons in nerve fibers in CLA group was faster and more complete than that in the vehicle group.

Conclusion: The current study demonstrates that CLA effectively attenuates NP and significantly inhibits neuro-inflammation and oxidative stress. This treatment improves sciatic nerve form and function after injury, suggesting that it can attenuate NP.

Keywords: Conjugated linoleic acid, Nerve pain, Oxidative stress, Neuro-inflammation