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

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.

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Effects of Pulsed Radiofrequency on Nerve Repair and Expressions of GFAP and GDNF in Rats with Neuropathic Pain

BioMed Research International ◽

10.1155/2021/9916978 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Qing Zhu ◽

Yi Yan ◽

Daying Zhang ◽

Qingtian Luo ◽

Cuihua Jiang

Keyword(s):

Neuropathic Pain ◽

Sciatic Nerve ◽

Western Blot ◽

Pain Sensitivity ◽

Treatment Time ◽

Nerve Repair ◽

Nerve Fibers ◽

Nerve Tissue ◽

Control Group ◽

Pulsed Radiofrequency

Objective. To study the effect of pulsed radio frequency (PRF) on nerve repair and the expression of GFAP and GDNF in rats with neuropathic pain. Methods. Thirty SPF healthy SD rats were randomly divided into control group (Group C), PSNL group (partial ligation of sciatic nerve) + sham group (Group PS), and PSNL group (partial ligation of sciatic nerve) + PRF group (Group PR), with 10 rats in each group. In group C, the right sciatic nerve was exposed without ligation. In the PS group, the model of neuropathic pain was established by partial ligation of sciatic nerve. The mice in the PR group were treated with PRF after establishing the neuropathic pain model. The general behavior of rats during the treatment was observed. The mechanical and thermal hyperalgesia were measured before operation and 1, 3, 7, and 14 days after operation. The content of inflammatory factors in nerve tissue was detected by ELISA. The pathological condition of nerve tissue was observed by HE. The gene and protein changes of GFAP and GDNF in nerve tissue were determined by QRT PCR and Western blot. Results. Rats in the control group were free to move and in good condition. In the PS group, there were different degrees of claudication, weakness of the lower limbs, lateral toe valgus, nerve injury, and other behavioral changes. After the pulsed radiofrequency in the PR group, the above symptoms decreased gradually with the prolongation of the treatment time. The mechanical pain sensitivity and thermal allodynia of the PS group were reduced after the operation. The mechanical pain sensitivity and thermal pain sensitivity of the PR group gradually increased with the prolongation of the treatment time, and the 14 days were basically close to the control group. The levels of TNF-α and IL-6 in ELISA were significantly higher in the PS group than in the control group, and the content in the PR group was gradually reduced, which was close to the control group. HE staining showed that the sciatic nerve fibers disappeared, and the formation of nerve cavities was obvious in the 14-day PS group. The nerve fibers were found in the sciatic tissue of the PR group, and there was no obvious hemorrhagic edema and cell deformation. The expression of GFAP mRNA in the PS group was significantly higher than that in the control group and the PR group ( p < 0.05 ), and the expression of GDNF was opposite ( p < 0.05 ). The results of western blot showed that the expression of GFAP protein in the 14-day PS group was significantly higher than that in the control group. The expression of the PR group decreased compared with the control group, and the expression of GDNF was opposite ( p < 0.05 ). Conclusion. Pulsed radiofrequency ablation can promote neurological repair, promote GDNF, and reduce the expression of GFAP in rats with neuropathic pain.

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Conjugated Linoleic Acid Causes a Marked Increase in Liver α-Tocopherol and Liver α-Tocopherol Transfer Protein in C57BL/6 J Mice

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000007 ◽

2010 ◽

Vol 80 (1) ◽

pp. 65-73 ◽

Cited By ~ 10

Author(s):

Pei-Min Chao ◽

Wan-Hsuan Chen ◽

Chun-Huei Liao ◽

Huey-Mei Shaw

Keyword(s):

Antioxidant Enzymes ◽

Linoleic Acid ◽

Conjugated Linoleic Acid ◽

Thiobarbituric Acid ◽

Control Group ◽

Thiobarbituric Acid Reactive Substances ◽

Control Groups ◽

Protein Levels ◽

Transfer Protein ◽

And Control

Conjugated linoleic acid (CLA) is a collective term for the positional and geometric isomers of a conjugated diene of linoleic acid (C18:2, n-6). The aims of the present study were to evaluate whether levels of hepatic α-tocopherol, α-tocopherol transfer protein (α-TTP), and antioxidant enzymes in mice were affected by a CLA-supplemented diet. C57BL/6 J mice were divided into the CLA and control groups, which were fed, respectively, a 5 % fat diet with or without 1 g/100 g of CLA (1:1 mixture of cis-9, trans-11 and trans-10, cis-12) for four weeks. α-Tocopherol levels in plasma and liver were significantly higher in the CLA group than in the control group. Liver α-TTP levels were also significantly increased in the CLA group, the α-TTP/β-actin ratio being 2.5-fold higher than that in control mice (p<0.01). Thiobarbituric acid-reactive substances were significantly decreased in the CLA group (p<0.01). There were no significant differences between the two groups in levels of three antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). The accumulation of liver α-tocopherol seen with the CLA diet can be attributed to the antioxidant potential of CLA and the ability of α-TTP induction. The lack of changes in antioxidant enzyme protein levels and the reduced lipid peroxidation in the liver of CLA mice are due to α-tocopherol accumulation.

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Conjugated linoleic acid enhanced the immune function in broiler chicks

British Journal Of Nutrition ◽

10.1079/bjn20051482 ◽

2005 ◽

Vol 94 (5) ◽

pp. 746-752 ◽

Cited By ~ 44

Author(s):

Haijun Zhang ◽

Yuming Guo ◽

Jianmin Yuan

Keyword(s):

Linoleic Acid ◽

Growth Performance ◽

Conjugated Linoleic Acid ◽

Antibody Production ◽

Peripheral Blood ◽

Lysozyme Activity ◽

Control Group ◽

Prostaglandin E ◽

Broiler Chicks ◽

Dietary Treatments

This study was undertaken to investigate the growth performance and immune responses of broiler chicks fed diets supplemented with conjugated linoleic acid (CLA). Two hundred and forty day-old Arbor Acre male broiler chicks were randomly allotted into four dietary treatments with different inclusion levels of CLA (0, 2·5, 5·0 or 10·0g pure CLA/kg) for 6 weeks. Growth performance, lysozyme activity, peripheral blood mononuclear cell (PBMC) proliferation, prostaglandin E2 (PGE2) synthesis and antibody production were investigated. There were no significant differences in growth performance among treatments (P>0·05). Chicks fed 10·0g CLA/kg diet produced 40% and 49% more lysozyme activity in serum and spleen than the control group at 21d of age (P<0·05). Dietary CLA enhanced the PBMC proliferation in response to concanavalin A at the age of 21 and 42d (P<0·05). Systemic and peripheral blood lymphocytic synthesis of PGE2 in chicks fed 10·0g CLA/kg diet was significantly decreased by 57% and 42% compared to chicks fed control diet (P<0·05). Antibody production to sheep red blood cell and bovine serum albumin were elevated in either 2·5 or 10·0g CLA/kg dietary treatments (P<0·05). The results indicated dietary CLA could enhance the immune response in broiler chicks, but did not alter the growth performance.

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Preemptive analgesic effect of lidocaine in a chronic neuropathic pain model

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x2009000600024 ◽

2009 ◽

Vol 67 (4) ◽

pp. 1088-1092 ◽

Cited By ~ 6

Author(s):

Leonardo M. Batista ◽

Igor M. Batista ◽

João P. Almeida ◽

Carlos H. Carvalho ◽

Samuel B. de Castro-Costa ◽

...

Keyword(s):

Neuropathic Pain ◽

Sciatic Nerve ◽

Control Group ◽

Thermal Stimulus ◽

Lidocaine Group ◽

Local Infiltration ◽

Neuropathic Pain Model ◽

Group 3 ◽

Group 2 ◽

The Right

Preemptive analgesia inhibits the progression of pain caused by surgical lesions. To analyze the effect of lidocaine on postoperative pain relief, we performed compression of the right sciatic nerve in Wistar rats and observed the differences on behavior between the group that received lidocaine and the group that was not treated with the local anesthetics pre-operatively. Group 1 was not operated (control); group 2 underwent the sciatic nerve ligature without lidocaine; group 3, underwent surgery with previous local infiltration of lidocaine. Group 2 showed significantly longer scratching times with a peak on day 14 post-operative (p=0.0005) and reduction in the latency to both noxious (p=0.003) and non-noxious (p=0.004) thermal stimulus. Group 3 presented significantly shorter scratching times (p=0.004) and longer latency times when compared to Group 2. Preemptive use of lidocaine 2% can potentially reduce the postoperative neuropathic pain associated with sciatic nerve compression.

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Internal-Specific Morphological Analysis of Sciatic Nerve Fibers in a Radiofrequency-Induced Animal Neuropathic Pain Model

PLoS ONE ◽

10.1371/journal.pone.0073913 ◽

2013 ◽

Vol 8 (9) ◽

pp. e73913 ◽

Cited By ~ 7

Author(s):

Samjin Choi ◽

Hyuk Jai Choi ◽

Youjin Cheong ◽

Young-Jin Lim ◽

Hun-Kuk Park

Keyword(s):

Neuropathic Pain ◽

Sciatic Nerve ◽

Morphological Analysis ◽

Nerve Fibers ◽

Pain Model ◽

Neuropathic Pain Model

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Functional and electron-microscopic changes after differential traction injury in the sciatic nerve of a rat

Maxillofacial Plastic and Reconstructive Surgery ◽

10.1186/s40902-021-00297-4 ◽

2021 ◽

Vol 43 (1) ◽

Author(s):

Soo-Hwan Byun ◽

Kang-Min Ahn

Keyword(s):

Sciatic Nerve ◽

Weight Ratio ◽

Control Group ◽

Muscle Weight ◽

Traction Injury ◽

Fiber Number ◽

Group A ◽

Myelin Thickness ◽

Group B ◽

G Ratio

Abstract Background During maxillofacial trauma or oral cancer surgery, peripheral nerve might be damaged by traction injury. The purpose of this study was to evaluate functional and histomorphometric changes after traction nerve injury in the sciatic nerve of a rat model. Methods A total of 24 Sprague-Dawley rats were equally divided into three groups: unstretched (sham/control, group A), stretched with 0.7N (group B) and 1.5N (group C). Traction injury was performed for 10 min in B and C groups. Functional recovery of the sciatic nerve was evaluated by walking track analysis, toe spread test, and pinprick test 2 weeks after injury. The weight of gastrocnemius muscles of both sides was measured to evaluate weight ratio (ipsilateral/contralateral). Total number of axons, axon fiber size, myelin thickness, G-ratio, axon number/mm2, diameter of fiber, changes of longitudinal width, and formation of the edema and hematoma were evaluated by transmission electron microscopy. Results The sciatic function indexes were −11.48±4.0, −15.11±14.84, and −49.12±35.42 for groups A, B, and C, respectively. Pinprick test showed 3.0, 2.86±0.38, and 1.38±0.52 for A, B, and group C. Muscle weight ratios were 0.98±0.13 for group A, 0.70±0.10 for group B, and 0.54±0.05 for group C. There were significant differences in toe spread test, pinprick test, and muscle weight ratio between control group and experimental group (p<0.001). In the experimental group, fiber number, fiber size, G-ratio, fiber number/mm2, myelin thickness, diameter of fiber, and longitudinal width were decreased with statistical significance. Conclusion The present study demonstrated that the nerve traction injury in the rat sciatic nerve damaged the motor and sensory function and axonal integrity. The amount of functional nerve damage was proportional to the amount of traction power and dependent on the initial tensile strengths (0.7N and 1.5N).

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Diazoxide Attenuates Postresuscitation Brain Injury in a Rat Model of Asphyxial Cardiac Arrest by Opening Mitochondrial ATP-Sensitive Potassium Channels

BioMed Research International ◽

10.1155/2016/1253842 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Haidong Wu ◽

Peng Wang ◽

Yi Li ◽

Manhui Wu ◽

Jiali Lin ◽

...

Keyword(s):

Cardiac Arrest ◽

Brain Injury ◽

Cell Apoptosis ◽

Brain Cell ◽

Vehicle Group ◽

Control Group ◽

Tunel Staining ◽

Sham Operation ◽

Sprague Dawley ◽

Mitokatp Channels

Objective. We investigated whether and how diazoxide can attenuate brain injury after cardiopulmonary resuscitation (CPR) by selective opening of mitochondrial ATP-sensitive potassium (mitoKATP) channels.Methods. Adult male Sprague-Dawley rats with induced cerebral ischemia (n=10per group) received an intraperitoneal injection of 0.1% dimethyl sulfoxide (1 mL; vehicle group), diazoxide (10 mg/kg; DZ group), or diazoxide (10 mg/kg) plus 5-hydroxydecanoate (5 mg/kg; DZ + 5-HD group) 30 min after CPR. The control group (sham group,n=5) underwent sham operation, without cardiac arrest. Mitochondrial respiratory control rate (RCR) was determined. Brain cell apoptosis was assessed using TUNEL staining. Expression of Bcl-2, Bax, and protein kinase C epsilon (PKCε) in the cerebral cortex was determined by Western blotting and immunohistochemistry.Results. The neurological deficit scores (NDS) in the vehicle group decreased significantly at 24 h and 48 h after CPR. Diazoxide significantly improved NDS and mitochondrial RCR after CPR at both time points; 5-HD cotreatment abolished these effects. Diazoxide decreased TUNEL-positive cells following CPR, upregulated Bcl-2 and PKCε, downregulated Bax, and increased the Bcl-2/Bax ratio; 5-HD cotreatment reversed these effects.Conclusions. Diazoxide attenuates postresuscitation brain injury, protects mitochondrial function, inhibits brain cell apoptosis, and activates the PKC pathway by opening mitoKATP channels.

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Flaxseed oil prevents trans-10, cis-12-conjugated linoleic acid-induced insulin resistance in mice

British Journal Of Nutrition ◽

10.1017/s0007114508027451 ◽

2008 ◽

Vol 101 (5) ◽

pp. 701-708 ◽

Cited By ~ 34

Author(s):

Darshan S. Kelley ◽

Madhuri Vemuri ◽

Yuriko Adkins ◽

Sher Himmat S. Gill ◽

Dawn Fedor ◽

...

Keyword(s):

Insulin Resistance ◽

Linoleic Acid ◽

Conjugated Linoleic Acid ◽

Cell Function ◽

Flaxseed Oil ◽

Control Group ◽

Β Cell ◽

Liver Lipids ◽

Alcoholic Fatty Liver ◽

Β Cell Function

Insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD) are found in 35 and 30 % of US adults, respectively. Trans-10, cis-12-conjugated linoleic acid (CLA) has been found to cause both these disorders in several animal models. We hypothesised that IR and NAFLD caused by CLA result from n-3 fatty acid deficiency. Pathogen-free C57BL/6N female mice (aged 8 weeks; n 10) were fed either a control diet or diets containing trans-10, cis-12-CLA (0·5 %) or CLA+flaxseed oil (FSO) (0·5 %+0·5 %) for 8 weeks. Weights of livers, concentration of circulating insulin, values of homeostatic model 1 (HOMA1) for IR and HOMA1 for β cell function were higher by 160, 636, 985 and 968 % in the CLA group compared with those in the control group. FSO decreased fasting glucose by 20 % and liver weights by 37 % compared with those in the CLA group; it maintained circulating insulin, HOMA1-IR and HOMA1 for β cell function at levels found in the control group. CLA supplementation decreased n-6 and n-3 wt% concentrations of liver lipids by 57 and 73 % and increased the n-6:n-3 ratio by 58 % compared with corresponding values in the control group. FSO increased n-6 and n-3 PUFA in liver lipids by 33 and 342 % and decreased the n-6:n-3 ratio by 70 % compared with corresponding values in the CLA group. The present results suggest that some adverse effects of CLA may be due to n-3 PUFA deficiency and that these can be corrected by a concomitant increase in the intake of α-linolenic acid, 18 : 3n-3.

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Nociceptive and Neuronal Evaluation of the Sciatic Nerve of Wistar Rats Subjected to Compression Injury and Treated with Resistive Exercise

Pain Research and Management ◽

10.1155/2016/6487160 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 3

Author(s):

Juliana Sobral Antunes ◽

Keli Lovison ◽

Jhenifer Karvat ◽

Ana Luiza Peretti ◽

Lizyana Vieira ◽

...

Keyword(s):

Sciatic Nerve ◽

Physical Exercise ◽

Resistance Exercise ◽

Wistar Rats ◽

Treated Group ◽

Nerve Fibers ◽

Lesion Group ◽

Control Group ◽

Compression Injury ◽

Inflammatory Infiltration

Background. To investigate the climb stairs resistance exercise on nociception and axonal regeneration in the sciatic nerve of rats.Methods. 24 Wistar rats were divided: control group (CG—no injury), exercise group (EG—no injury with physical exercise), lesion group (LG—injury, but without exercise), and treated group (LEG—injury and physical exercise). LG and LEG were subjected to sciatic nerve compression with hemostat. From the 3rd day after injury began treatment with exercise, and after 22 days occurs the removal of a nerve fragment for morphological analysis.Results. Regarding allodynia, CG obtained values less than EG(p=0.012)and larger than LG and LEG(p<0.001). Histological results showed that CG and EG had normal appearance, as LG and LEG showed up with large amounts of inflammatory infiltration, degeneration and disruption of nerve fibers, and reduction of the myelin sheath; however LEG presented some regenerated fibers. From the morphometric data there were significant differences, for nerve fiber diameter, comparing CG with LG and LEG and comparing axon diameter and the thickness of the myelin of the CG to others.Conclusion. Climb stairs resistance exercise was not effective to speed up the regenerative process of axons.

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Conjugated linoleic acid induces lipid peroxidation in men with abdominal obesity

Clinical Science ◽

10.1042/cs0990511 ◽

2000 ◽

Vol 99 (6) ◽

pp. 511-516 ◽

Cited By ~ 50

Author(s):

S. BASU ◽

U. RISÉRUS ◽

A. TURPEINEN ◽

B. VESSBY

Keyword(s):

Lipid Peroxidation ◽

Linoleic Acid ◽

Conjugated Linoleic Acid ◽

Abdominal Obesity ◽

Experimental Studies ◽

Prostaglandin F2α ◽

Control Group ◽

Acid Oxidation ◽

Middle Aged ◽

Urinary Levels

Conjugated linoleic acid (CLA) has been shown in experimental studies to have chemoprotective properties, and may decrease the deposition of body fat. CLA is prone to oxidation, and it has been suggested that increased lipid oxidation may contribute to the anti-tumorigenic effects of this agent. The present study investigates the urinary levels of 8-iso-prostaglandin F2α (8-iso-PGF2α), a major isoprostane, and of 15-oxo-dihydro-PGF2α, a major metabolite of PGF2α, as indicators of non-enzymic and enzymic arachidonic acid oxidation respectively after dietary supplementation with CLA in middle-aged men (mean age 53 years) with abdominal obesity for 1 month in a randomized controlled trial. Significant increases in the levels of both 8-iso-PGF2α and 15-oxo-dihydro-PGF2α in urine (P < 0.0001 and P = 0.0013 respectively) were observed after 1 month of daily CLA intake (4.2 g/day) as compared with the control group. The lipid peroxidation parameters had returned to their basal levels at 2 weeks after the cessation of CLA intake, and remained at the same levels for a further 2 weeks until the end of the study. CLA had no effect on serum α-tocopherol and γ-tocopherol levels, or on the urinary levels of 2,3-dinor-thromboxane B2. Thus CLA may induce both non-enzymic and enzymic lipid peroxidation in vivo in middle-aged men with abdominal obesity, without any side effects. The consequences of the increased lipid peroxidation after CLA supplementation are unknown.

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