Tag: rat study

Hyperactivation of proprioceptors induces microglia-mediated long-lasting pain in a rat model of chronic fatigue syndrome

Abstract:

BACKGROUND: Patients diagnosed with chronic fatigue syndrome (CFS) or fibromyalgia experience chronic pain. Concomitantly, the rat model of CFS exhibits microglial activation in the lumbar spinal cord and pain behavior without peripheral tissue damage and/or inflammation. The present study addressed the mechanism underlying the association between pain and chronic stress using this rat model.

METHODS: Chronic or continuous stress-loading (CS) model rats, housed in a cage with a thin level of water (1.5 cm in depth), were used. The von Frey test and pressure pain test were employed to measure pain behavior. The neuronal and microglial activations were immunohistochemically demonstrated with antibodies against ATF3 and Iba1. Electromyography was used to evaluate muscle activity.

RESULTS: The expression of ATF3, a marker of neuronal hyperactivity or injury, was first observed in the lumbar dorsal root ganglion (DRG) neurons 2 days after CS initiation. More than 50% of ATF3-positive neurons simultaneously expressed the proprioceptor markers TrkC or VGluT1, whereas the co-expression rates for TrkA, TrkB, IB4, and CGRP were lower than 20%. Retrograde labeling using fluorogold showed that ATF3-positive proprioceptive DRG neurons mainly projected to the soleus. Substantial microglial accumulation was observed in the medial part of the dorsal horn on the fifth CS day. Microglial accumulation was observed around a subset of motor neurons in the dorsal part of the ventral horn on the sixth CS day. The motor neurons surrounded by microglia were ATF3-positive and mainly projected to the soleus. Electromyographic activity in the soleus was two to three times higher in the CS group than in the control group. These results suggest that chronic proprioceptor activation induces the sequential activation of neurons along the spinal reflex arc, and the neuronal activation further activates microglia along the arc. Proprioceptor suppression by ankle joint immobilization significantly suppressed the accumulation of microglia in the spinal cord, as well as the pain behavior.

CONCLUSION: Our results indicate that proprioceptor-induced microglial activation may be a key player in the initiation and maintenance of abnormal pain in patients with CFS.

Source: Yasui M, Menjyo Y, Tokizane K, Shiozawa A, Tsuda M, Inoue K, Kiyama H. Hyperactivation of proprioceptors induces microglia-mediated long-lasting pain in a rat model of chronic fatigue syndrome. J Neuroinflammation. 2019 Mar 30;16(1):67. doi: 10.1186/s12974-019-1456-x. https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-019-1456-x (Full article)

Effect of Swarna Jibanti (Coelogyne cristata Lindley) in alleviation of chronic fatigue syndrome in aged Wistar rats

Abstract:

BACKGROUND: Swarna Jibanti scientifically known as Coelogyne cristata Lindley (Orchidaceae), an orchid mentioned in Ayurvedic medicine is used to promote healthy life span.

OBJECTIVE: The present work was planned to study the efficacy of hydro-alcoholic extract of pseudobulbs of C.cristata (CCE) to assess its role on chronic fatigue syndrome (CFS) induced behavioural and biochemical changes in aged Wistar rats compared to Panax ginseng (PG), a prototype anti-stress agent.

MATERIALS AND METHODS: CFS was induced by forced swimming for consecutive 21 days for fixed duration (15 min sessions). The criteria of CFS due to fatigue were counted using locomotor activity, depression and anxiety through automated photactometer, immobility time and plus maze activity respectively. Acute toxicity study of CCE (upto 2 g/kg, Limit test) was also performed. For CFS, animals were divided into five groups, naive control, control, CCE treated (25 mg/kg b.w., 250 mg/kg b.w.) and standard PG treated (100 mg/kg b.w.) groups. All drugs were given orally for consecutive 21 days along with CFS. After assessing behavioural parameters, all animals were sacrificed at day 21 and in vivo antioxidant potential of CCE was determined by lipid peroxides, nitrite, catalase (CAT) and superoxide dismutase (SOD) in brain tissue.

RESULTS: CCE was found to be non-toxic. CCE treated aged rats significantly improved (p < 0.001) the spontaneous locomotor movement with respect to control rats, while, decreased the mobility period or depression score. In CFS, CCE also enhanced the time spent (p < 0.001) in open arms while reducing the time spent in closed arm as compared to CFS control, indicating lowering anxiety score. Moreover, marked diminution in lipid peroxidation, nitrite and SOD level was exhibited after CCE treatment and significantly enhanced catalase level significantly (p < 0.01) with respect to CFS control. PG also showed similar actions.

CONCLUSION: The results confirmed the potential therapeutic actions of CCE against experimentally induced CFS in aged rats that might be due to its CNS mediatory antioxidant properties.

Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

Source: Mitra A, Sur TK, Upadhyay S, Bhattacharyya D, Hazra J. Effect of Swarna Jibanti (Coelogyne cristata Lindley) in alleviation of chronic fatigue syndrome in aged Wistar rats. J Ayurveda Integr Med. 2017 Nov 1. pii: S0975-9476(17)30217-6. doi: 10.1016/j.jaim.2017.06.011. [Epub ahead of print] http://www.sciencedirect.com/science/article/pii/S0975947617302176 (Full article)

Effect of Acupuncture on the Expression of Transcription Factor T-bet/GATA-3 in Plasma of Rats with Chronic Fatigue Syndrome

Abstract:

OBJECTIVE: To observe the effect of acupuncture on the expression of T-box expressed in T cell (T-bet)/GATA binding factor-3 (GATA-3) in plasma of rats with chronic fatigue syndrome (CFS) and explore the mechanism of acupuncture treatment for CFS.

METHODS: Forty-eight healthy male SD rats were randomly divided into blank control group, CFS model group, acupuncture group, and ginsenoside group (12 rats in each group). CFS rat model was established by combining restriction and cold water swimming. Acupuncture was applied to “Baihui”(GV 20), “Guanyuan” (CV 4) and “Zusanli” (ST 36, bilate-ral) acupoints, once a day for two weeks. The ginsenoside group was gavage administrated with ginsenoside, once a day for two weeks. After 14 days, behavioural changes were observed, and the expression levels of T-bet/GATA-3 genes in plasma were detected by RT-PCR.

RESULTS: Compared with the blank control group, the time for immobility of forced suspensory test was signi-ficantly longer (P<0.05) and the time for exhaustive swimming was significantly shortened (P<0.05) in the CFS model group. Compared with the model group, the two indexes above-mentioned were reversed (P<0.05) both in the acupuncture group and the ginsenoside group, and the effects in the acupuncture group were more significant than those in the ginsenoside group (P<0.05). Compared with the blank control group, the expression level of T-cell transcription factor T-bet gene in plasma was higher in the CFS model group (P<0.05), companied with lower GATA-3 gene expression (P<0.05). The ratio of T-bet/GATA-3 was higher in the model group than in the blank control group(P<0.05). Compared with the CFS model group, all the indexes above-mentioned were reversed (P<0.05) in the two treatment groups. Acupuncture group showed a better effect on reducing T-bet gene expression than the ginsenoside group (P<0.05).

CONCLUSIONS: Acupuncture can decrease the expression level of T-bet gene while increase the expression of GATA-3 gene, which may be associated with its role in treating CFS.

Source: Wang XY, Liu CZ, Lei B. Effect of Acupuncture on the Expression of Transcription Factor T-bet/GATA-3 in Plasma of Rats with Chronic Fatigue Syndrome. Zhen Ci Yan Jiu. 2017 Jun 25;42(3):246-8. [Article in Chinese] https://www.ncbi.nlm.nih.gov/pubmed/29071982

The variation of the 5-hydroxytryptamine system between chronic unpredictable mild stress rats and chronic fatigue syndrome rats induced by forced treadmill running

Abstract:

The aim of this study was to observe the variation in the 5-hydroxytryptamine (5-HT) system between a chronic unpredictable mild stress (CUMS) model and a chronic fatigue syndrome (CFS) model. The total distance, the crossing pieces, and rearing times in the open-field test of the CUMS group and the CFS group were all less than those of the control group to different degrees.

The concentrations of tryptophan, 5-HT, and 5-HIAA of the CUMS group were obviously lower than those of the control group. In the CFS model, the concentrations of tryptophan, 5-HT, and 5-HIAA were obviously higher than those of the control group. The expressions of tryptophan hydroxylase-2 (TPH-2) and 5-HT1A receptor in protein level and mRNA level were also different among the three groups. The expressions of TPH-2 and 5-HT1A were higher in the CFS group than in the CUMS group. The expressions of TPH-2 and 5-HT1A receptor were lower in the CUMS group than in the control group. We can find that in different situations of mood disorders, the variation of 5-HT system may also be opposite.

Source: Cao Y, Li Q. The variation of the 5-hydroxytryptamine system between chronic unpredictable mild stress rats and chronic fatigue syndrome rats induced by forced treadmill running. Neuroreport. 2017 May 12. doi: 10.1097/WNR.0000000000000797. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28505018

Detection of Urine Metabolites in a Rat Model of Chronic Fatigue Syndrome before and after Exercise

Abstract:


Purpose. The aim of the present study was to elucidate the metabolic mechanisms associated with chronic fatigue syndrome (CFS) via an analysis of urine metabolites prior to and following exercise in a rat model.

Methods. A rat model of CFS was established using restraint-stress, forced exercise, and crowded and noisy environments over a period of 4 weeks. Behavioral experiments were conducted in order to evaluate the model. Urine metabolites were analyzed via gas chromatography-mass spectrometry (GC-MS) in combination with multivariate statistical analysis before and after exercise.

Results. A total of 20 metabolites were detected in CFS rats before and after exercise. Three metabolic pathways (TCA cycle; alanine, aspartate, and glutamate metabolism; steroid hormone biosynthesis) were significantly impacted before and after exercise, while sphingolipid metabolism alone exhibited significant alterations after exercise only.

Conclusion. In addition to metabolic disturbances involving some energy substances, alterations in steroid hormone biosynthesis and sphingolipid metabolism were detected in CFS rats. Sphingosine and 21-hydroxypregnenolone may be key biomarkers of CFS, potentially offering evidence in support of immune dysfunction and hypothalamic-pituitary-adrenal (HPA) axis hypoactivity in patients with CFS.


Source: Shao C, Ren Y, Wang Z, Kang C, Jiang H, Chi A. Detection of Urine Metabolites in a Rat Model of Chronic Fatigue Syndrome before and after Exercise. Biomed Res Int. 2017;2017:8182020. doi: 10.1155/2017/8182020. Epub 2017 Mar 22. https://www.hindawi.com/journals/bmri/2017/8182020/ (Full article)

 

Characterization of a protein-bound polysaccharide from Herba Epimedii and its metabolic mechanism in chronic fatigue syndrome

Abstract:

OBJECTIVES: Herba Epimedii is one of the famous Traditional Chinese Medicines used to treat the chronic fatigue syndrome (CFS). The polysaccharides are the main active components in Herba Epimedii. The aim of this study is to discover the therapeutic effect and metabolic mechanism of Herba Epimedii polysaccharides against CFS.

METHODS: The polysaccharide conjugates named HEP2-a were isolated from the leaves of Herba Epimedii using a water extraction method, and the general physicochemical properties of HEP2-a were analysed. In addition, a CFS rat model was established, and then, urinary metabonomic studies were performed using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) in combination with multivariate statistical analysis.

RESULTS: The physicochemical properties revealed that HEP2-a had an average molecular weight of 13.6×104 Da and consisted of mannose (4.41%), rhamnose (5.43%), glucose (31.26%), galactose (27.07%), arabinose (23.43%), and galacturonic acid (8.40%). The amino acids in HEP2-a include glutamate, cysteine, leucine, tyrosine, lysine, and histidine. Molecular morphology studies revealed many highly curled spherical particles with diameters of 5-10µm in solids and 100-200nm for particles in water. Five metabolites in the HEP2-a group were oppositely and significantly changed compared to the CFS model group.

CONCLUSION: Two metabolic pathways were identified as significant metabolic pathways involved with HEP2-a. The therapeutic effects of HEP2-a on CFS were partially due to the restoration of these disturbed pathways.

Copyright © 2017. Published by Elsevier B.V.

 

Source: Chi A, Shen Z, Zhu W, Sun Y, Kang Y, Guo F. Characterization of a protein-bound polysaccharide from Herba Epimedii and its metabolic mechanism in chronic fatigue syndrome. J Ethnopharmacol. 2017 Mar 27. pii: S0378-8741(16)31138-2. doi: 10.1016/j.jep.2017.03.041. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28359851

 

Metabolic mechanism of a polysaccharide from Schisandra chinensis to relieve chronic fatigue syndrome

Abstract:

Schisandra chinensis fruits are a famous traditional Chinese medicine to treat all kinds of fatigue. This study aimed to investigate the therapeutic effect and metabolic mechanism of a polysaccharide (SCP) from Schisandra chinensis fruits on chronic fatigue syndrome (CFS). SCP was isolated and the physicochemical properties were analyzed.

A CFS model of rats was established and the urinary metabonomic studies were performed using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) in combination with multivariate statistical analysis. The results showed that SCP is a protein-bound polysaccharide. The amino acid composition of SCP consisted of 12 amino acids.

The growth and the behaviors of the rats in the CFS model group were worse than those in the control group and improved after SCP treatment. Analysis of the GC-TOF-MS revealed that twelve metabolites were significantly changed, and six metabolites were oppositely and significantly changed after the SCP treatment. The TCA cycle metabolic pathways and the alanine, aspartate and glutamate metabolism were identified as significant metabolic pathways involved with SCP. The therapeutic mechanism of SCP against CFS was partially due to the restoration of these disturbed pathways.

Copyright © 2016 Elsevier B.V. All rights reserved.

 

Source: Chi A, Zhang Y, Kang Y, Shen Z. Metabolic mechanism of a polysaccharide from Schisandra chinensis to relieve chronic fatigue syndrome. Int J Biol Macromol. 2016 Dec;93(Pt A):322-332. doi: 10.1016/j.ijbiomac.2016.08.042. Epub 2016 Aug 18. https://www.ncbi.nlm.nih.gov/pubmed/27545408

 

Investigation of the effects of vanilloids in chronic fatigue syndrome

Abstract:

AIM OF THE STUDY: To assess the effectiveness of TRPV1 modulators in animal model of Chronic fatigue syndrome (CFS). To assess central and peripheral behavioral activity of TRPV1 modulators.

MATERIAL AND METHODS: CFS was induced by forcing the rats to swim for 10min for 21 consecutive days. The rats were treated with capsaicin (TRPV1 agonist, 2.5mg/kg) and n-tert-butylcyclohexanol (TRPV1 antagonist, 10mg/kg) for 21days 30min before the exposure to stress procedure. The behavioral consequence of CFS was measured in terms of immobility time, grip strength, locomotor activity, and anxiety level using Rota rod, Actophotometer, and Elevated plus maze model respectively. The other parameters include Plasma corticosterone, adrenal gland and spleen weight, complete blood count, blood urea niterogen (BUN), Lactate dehydrogenase (LDH), Lipid peroxidation, catalase and reduced glutathione (GSH).

RESULTS AND DISCUSSION: TRPV1 modulators reversed (p<0.05) the increase in immobility period, anxiety, spleen weight, BUN and LDH levels, and MDA levels along with decrease in grip strength, locomotor activity, plasma corticosterone, adrenal gland weight, catalase, and GSH. There was also significant increase in total WBC count when compared with the disease control group. The reversal was attributed to modulation of HPA axis, oxidative stress, anaerobic respiration product, muscle degradation product.

CONCLUSION: The present study reveals the effectiveness of n-tert-butylcyclohexanol and capsaicin against chronic fatigue syndrome. The mechanism of action can be attributed to inhibition of TRPV1 channel and thereby modulating pain perception, neuroendocrine function, oxidative stress and immune function.

Copyright © 2016 Elsevier Inc. All rights reserved.

 

Source: Sarvaiya K, Goswami S. Investigation of the effects of vanilloids in chronic fatigue syndrome. Brain Res Bull. 2016 Oct;127:187-194. doi: 10.1016/j.brainresbull.2016.09.015. Epub 2016 Sep 28. https://www.ncbi.nlm.nih.gov/pubmed/27693335

 

Immunomodulating and antioxidant effects of polysaccharide conjugates from the fruits of Ziziphus Jujube on Chronic Fatigue Syndrome rats

Abstract:

To detect the treatment effect of the fruits of Ziziphus Jujube in Chronic Fatigue Syndrome (CFS). Jujube polysaccharide conjugates (JPC) were isolated from the fruits of Z. Jujube. General physicochemical properties of JPC were analyzed.

A four-week rats CFS model was established and JPC were orally administrated, the behavior experiments were conducted after CFS. The activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the levels of malondialdehyde (MDA) in serum were elevated and T lymphocyte proliferation, CD4(+)/CD8(+) ratio and natural killer (NK) cells activity were analyzed.

JPC markedly improved behaviors of CFS rats, also decreased MDA levels in serum, and elevated T lymphocyte proliferation, CD4(+)/CD8(+) ratio and natural killer (NK) cells activities. This suggests that JPC can improve the immune system and antioxidant activity of CFS rats and might be regarded as a biological response modifier.

Copyright © 2015 Elsevier Ltd. All rights reserved.

 

Source: Chi A, Kang C, Zhang Y, Tang L, Guo H, Li H, Zhang K. Immunomodulating and antioxidant effects of polysaccharide conjugates from the fruits of Ziziphus Jujube on Chronic Fatigue Syndrome rats. Carbohydr Polym. 2015 May 20;122:189-96. doi: 10.1016/j.carbpol.2014.12.082. Epub 2015 Jan 14. https://www.ncbi.nlm.nih.gov/pubmed/25817658

 

Effect of manual acupuncture stimulation of “Baihui” (GV 20), etc. on serum IFN-gamma and IL-4 contents in rats with chronic fatigue syndrome

Abstract:

OBJECTIVE: To observe the effect of manual acupuncture stimulation of “Baihui” (GV 20), etc. on serum IFN- gamma and IL-4 contents in rats with chronic fatigue syndrome (CFS).

METHODS: A total of 24 male SD rats were equally randomized into control group, model group and acupuncture group. CFS model was established by bounding and forced swimming in cold water once daily for 14 days. Rats in the acupuncture group were treated by manual acupuncture stimulation of bilateral “Zusanli” (ST 36), “Baihui” (GV 20), and “Guanyuan” (CV 4), once daily for 14 days. Serum IFN-gamma and IL-4 contents were detected by ELISA.

RESULTS: Compared with the control group, the contention of serum IFN-gamma and ratio of IFN-gamma/IL-4 were significant decreased in the model group (P<0.01). While in comparison with the model group, the contention of IFN-gamma and ratio of IFN-gamma/IL-4 were obviously increased in the acupuncture group (P<0.05). No significant differences were found among the three groups in serum IL-4 levels (P>0.05).

CONCLUSION: Manual acupuncture can inhibit CFS induced reduction of serum IFN-gamma level and the ratio of IFN-gamma/IL-4 in CFS rats, suggesting a favorable adjustment of acupuncture intervention for CFS by balancing the ratio of IFN-gamma/IL-4.

 

Source: Wang C, Xie WJ, Liu M, Yan J, Zhang JL, Liu Z, Guo LN. Effect of manual acupuncture stimulation of “Baihui” (GV 20), etc. on serum IFN-gamma and IL-4 contents in rats with chronic fatigue syndrome. Zhen Ci Yan Jiu. 2014 Oct;39(5):387-9. [Article in Chinese] https://www.ncbi.nlm.nih.gov/pubmed/25518113