scholarly journals Novel Mechanism for Memantine in Attenuating Diabetic Neuropathic Pain in Mice via Downregulating the Spinal HMGB1/TRL4/NF-kB Inflammatory Axis

2021 ◽  
Vol 14 (4) ◽  
pp. 307
Author(s):  
Suliman Y. Alomar ◽  
Rehab E. Abo El Gheit ◽  
Eman T. Enan ◽  
Khaled S. El-Bayoumi ◽  
Mohamed Z. Shoaeir ◽  
...  

Diabetic neuropathic pain (DNP) is a common diabetic complication that currently lacks an efficient therapy. The aim of the current work was to uncover the anti-allodynic and neuroprotective effects of memantine in a model of mouse diabetic neuropathy and its ameliorative effect on the high-mobility group box-1 (HMGB1)/toll-like receptor 4 (TLR4)/nuclear factor-k B (NF-kB) inflammatory axis. Diabetes was prompted by an alloxan injection (180 mg/kg) to albino mice. On the ninth week after diabetes induction, DNP was confirmed. Diabetic mice were randomly allocated to two groups (six mice each); a diabetes mellitus (DM) group and DM+memantine group (10 mg/kg, daily) for five weeks. DNP-related behaviors were assessed in terms of thermal hyperalgesia and mechanical allodynia by hot-plate and von Frey filaments. Enzyme-linked immunosorbent assay (ELISA) kits were used to measure the spinal glutamate, interleukin-1 beta (IL-1β), and tumor necrosis factor-α (TNF-α). The spinal levels of N-methyl-D-aspartate type 1 receptor (NMDAR1), HMGB1, TLR4, and phosphorylated NF-kB were assessed using Western blotting. Histopathological investigation of the spinal cord and sciatic nerves, together with the spinal cord ultrastructure, was employed for assessment of the neuroprotective effect. Memantine alleviated pain indicators in diabetic mice and suppressed excessive NMDAR1 activation, glutamate, and pro-inflammatory cytokine release in the spinal cord. The current study validated the ability of memantine to combat the HMGB1/TLR4/NF-kB axis and modulate overactive glutamate spinal transmission, corroborating memantine as an appealing therapeutic target in DNP.

2020 ◽  
Vol 10 (10) ◽  
pp. 731
Author(s):  
Muhammad Faheem ◽  
Syed Hussain Ali ◽  
Abdul Waheed Khan ◽  
Mahboob Alam ◽  
Umair Ilyas ◽  
...  

The production and up-regulation of inflammatory mediators are contributing factors for the development and maintenance of neuropathic pain. In the present study, the post-treatment of synthetic 1,3,4 oxadiazole derivative (B3) for its neuroprotective potential in chronic constriction injury-induced neuropathic pain was applied. In-silico studies were carried out through Auto Dock, PyRx, and DSV to obtain the possible binding and interactions of the ligands (B3) with COX-2, IL-6, and iNOS. The sciatic nerve of the anesthetized rat was constricted with sutures 3/0. Treatment with 1,3,4-oxadiazole derivative was started a day after surgery and continued until the 14th day. All behavioral studies were executed on day 0, 3rd, 7th, 10th, and 14th. The sciatic nerve and spinal cord were collected for further molecular analysis. The interactions in the form of hydrogen bonding stabilizes the ligand target complex. B3 showed three hydrogen bonds with IL-6. B3, in addition to correcting paw posture/deformation induced by CCI, attenuates hyperalgesia (p < 0.001) and allodynia (p < 0.001). B3 significantly raised the level of GST and GSH in both the sciatic nerve and spinal cord and reduced the LPO and iNOS (p < 0.001). B3 attenuates the pathological changes induced by nerve injury, which was confirmed by H&E staining and IHC examination. B3 down-regulates the over-expression of the inflammatory mediator IL-6 and hence provides neuroprotective effects in CCI-induced pain. The results demonstrate that B3 possess anti-nociceptive and anti-hyperalgesic effects and thus minimizes pain perception and inflammation. The possible underlying mechanism for the neuroprotective effect of B3 probably may be mediated through IL-6.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hengtao Xie ◽  
Yingying Chen ◽  
Wei Wu ◽  
Xiaobo Feng ◽  
Kairong Du

Vincristine (Vin) is a well-known antitumor agent that frequently evokes neuropathic pain and decreases the quality of life of patients. Polysaccharides (GBP) extracted from Gastrodia elata Blume have been demonstrated to possess anti-inflammatory and neuroprotective effects in vivo; however, the effects of GBP on Vin-induced neuropathic pain remain unknown. The present study is aimed at exploring the alleviative potential of GBP against chemotherapy-evoked peripheral neuropathy to better understand and extend its pharmacological application. Vin was administered intraperitoneally to evoke neuropathic pain. GBP was orally administered for 21 days. The mechanical allodynia and thermal hyperalgesia were assessed using the Von Frey test and hot-plate test. Histopathological changes were assessed by hematoxylin and eosin staining. ELISA kits were used to measure the levels of inflammatory cytokines in the sciatic nerve, spinal cord, and dorsal root ganglion (DRG). qRT-PCR was employed to examine the expression of inflammatory cytokines and Sirtuin1 (SIRT1) in the sciatic nerve, spinal cord, and DRG. Our findings revealed that GBP treatment enhanced the paw withdrawal latency and paw withdrawal threshold and restored Vin-induced sciatic nerve damage in rats. GBP also attenuated the Vin-induced increase of proinflammatory cytokine levels, including IL-6, IL-8, TNF-α, IL-1β, and NF-κB. On the molecular level, treatment with GBP downregulated the mRNA levels of IL-6, IL-8, TNF-α, and IL-1β in the sciatic nerve, spinal cord, and DRG. Meanwhile, GBP increased SIRT1 activity and mRNA expression levels. Our data indicated that GBP exerted a potential protective effect against chemotherapy-induced neuropathic pain which might be mediated via the inhibition of neuroinflammation.


2019 ◽  
Vol 33 ◽  
pp. 205873841986637 ◽  
Author(s):  
Mei Liu ◽  
Linlin Gao ◽  
Na Zhang

We aimed to analyze the action of berberine on the neuropathic pain and neuroglia activation in experimental diabetes mellitus (DM) model. Diabetes in mice was induced by intraperitoneal injection of streptozotocin (STZ) followed by the administration of berberine. Mechanical allodynia and thermal hyperalgesia and activations of microglia and astrocytes were evaluated. The levels of pro-inflammatory cytokines and protein expressions of inflammatory proteins were assessed by enzyme-linked immunosorbent assay (ELISA) and western blot, respectively. Our results revealed the anti-nociceptive effects of berberine in DM mice, supported by the improved mechanical threshold and thermal latency. In addition, berberine suppressed the activations of microglia and astrocytes in the spinal cords of diabetic mice. Berberine inhibited the expression of pro-inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), and interleukin-1β (IL-1β), along with inflammatory proteins including iNOS and COX-2. Berberine suppressed neuropathic pain in STZ-induced diabetic mice, and this effect is related to the reduction on the neuroglia activation and inflammation associated with DM.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yu-Qing Ma ◽  
Yi-Rong Chen ◽  
Yu-Fang Leng ◽  
Zhi-Wei Wu

Fifty-four Sprague-Dawley rats weighing 200~240 g were randomly divided into sham-operated group (sham group), vehicle-treated SNL group (model group), and Tan IIA-treated SNL group (Tan IIA group). Tan IIA was administered intraperitoneally to rats in the Tan IIA-treated group at a dose of 30 mg/kg daily for 14 days after SNL surgery. Paw withdrawal mechanical thresholds (PWTs) and paw withdrawal thermal latencies (PWLs) were measured. High-mobility group box 1 (HMGB1) and Toll-like Receptor 4 (TLR4) mRNA and protein expression in the spinal cord were measured. Tumour necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-10 (IL-10) in the spinal cord were measured, too. Both the mechanical and heat pain thresholds were significantly decreased. After Tan IIA treatment, HMGB1, and TLR4 mRNA and protein levels, the expression of TNF-αand IF-1βwas reduced significantly. In conclusion, Tanshinone IIA reversed SNL-induced thermal hyperalgesia and mechanical allodynia and downregulated HMGB1 and TLR4 levels and inhibited the HMGB1-TLR4 pathway. Tanshinone IIA inhibited TNF-αand IL-1βexpression but not IF-10 expression in the spinal cords of SNL rats. These results indicate that Tanshinone IIA inhibited SNL-induced neuropathic pain via multiple effects, and targeting the HMGB1-TLR4 pathway could serve as the basis of new antinociceptive agents.


2021 ◽  
Vol 17 ◽  
pp. 174480692199652
Author(s):  
Feng Zhou ◽  
Xian Wang ◽  
Baoyu Han ◽  
Xiaohui Tang ◽  
Ru Liu ◽  
...  

Microglia activation and subsequent pro-inflammatory responses play a key role in the development of neuropathic pain. The process of microglia polarization towards pro-inflammatory phenotype often occurs during neuroinflammation. Recent studies have demonstrated an active role for the gut microbiota in promoting microglial full maturation and inflammatory capabilities via the production of Short-Chain Fatty Acids (SCFAs). However, it remains unclear whether SCFAs is involved in pro-inflammatory/anti-inflammatory phenotypes microglia polarization in the neuropathic pain. In the present study, chronic constriction injury (CCI) was used to induce neuropathic pain in mice, the mechanical withdrawal threshold, thermal hyperalgesia were accomplished. The levels of microglia markers including ionized calcium-binding adaptor molecule 1 (Iba1), cluster of differentiation 11b (CD11b), pro-inflammatory phenotype markers including CD68, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and anti-inflammatory phenotype markers including CD206, IL-4 in the hippocampus and spinal cord were determined on day 21 after CCI. The results showed that CCI produced mechanical allodynia and thermal hyperalgesia, and also increased the expressions of microglia markers (Iba1, CD11b) and pro-inflammatory phenotype markers (CD68, IL-1β, and TNF-α), but not anti-inflammatory phenotype marker (CD206, IL-4) in the hippocampus and spinal cord, accompanied by increased SCFAs in the gut. Notably, antibiotic administration reversed these abnormalities, and its effects was also bloked by SCFAs administration. In conclusion, data from our study suggest that CCI can lead to mechanical and thermal hyperalgesia, while SCFAs play a key role in the pathogenesis of neuropathic pain by regulating microglial activation and subsequent pro-inflammatory phenotype polarization. Antibiotic administration may be a new treatment for neuropathic pain by reducing the production of SCFAs and further inhibiting the process of microglia polarization.


2012 ◽  
Vol 18 (S5) ◽  
pp. 5-6 ◽  
Author(s):  
Carla Morgado ◽  
João Silva ◽  
André Miranda ◽  
Patrícia Pereira-Terra ◽  
Diogo Raposo ◽  
...  

Diabetes is a major health problem with an alarming increasing prevalence, and is the most frequent cause of neuropathy worldwide. Neuropathy affects 50–60% of diabetic patients, being a major life-quality impairment for a quarter of these patients. Diabetic neuropathic pain (DNP) is characterized by spontaneous pain, mechanical hyperalgesia and tactile allodynia and is accompanied by functional and neurochemical changes at the peripheral nerves, spinal cord and supraspinal pain control areas. Regarding the effects of diabetic neuropathy in the central somatossensory system, it was shown that streptozotocin (STZ)-diabetic rats present spontaneous hyperactivity and hyperexcitability of spinal nociceptive neurons, which may be subserving the exacerbated pain responses. The spinal functional changes and pain may be due to increased peripheral input(2), changes in spinal nociceptive modulatory mechanisms and altered supraspinal descending pain modulation. Noradrenergic descending pain modulation seems to be impaired since STZ-diabetic rats present decreased numbers of noradrenergic neurons at the A5 and A7 pontine cell groups, along with lower levels of noradrenaline at the spinal cord and higher behavioral responses to pain. This is consistent with the strong noradrenergic projection from A5 and A7 neurons to the spinal dorsal horn and the modulation of nociceptive transmission by local release of noradrenaline. The mechanisms underlying the decrease in noradrenergic neurons in the brainstem during diabetes remain unclear. Our recent findings that diabetes induces oxidative stress damage in neurons from those areas, lead us to hypothesize that it may contribute to their loss. Thereafter, with the present study we aimed to evaluate the effects of Epigallocathechin Gallate (EGCG), a potent antioxidant present in green tea, on spinal noradrenaline levels, on A5 and A7 noradrenergic neurons and on behavioral pain responses of STZ-diabetic rats.


2002 ◽  
Vol 87 (6) ◽  
pp. 2726-2733 ◽  
Author(s):  
Shao-Rui Chen ◽  
Hui-Lin Pan

Diabetic neuropathic pain is often considered to be caused by peripheral neuropathy. The involvement of the CNS in this pathological condition has not been well documented. Development of hypersensitivity of spinal dorsal horn neurons is involved in neuropathic pain induced by traumatic nerve injury. In the present study, we determined the functional changes of identified spinothalamic tract (STT) neurons and their correlation to diabetic neuropathic pain. Diabetes was induced in rats by intraperitoneal injection of streptozotocin. Hyperalgesia and allodynia were assessed by the withdrawal responses to pressure, radiant heat, and von Frey filaments applied to the hindpaw. Single-unit activity of STT neurons was recorded from the lumbar spinal cord in anesthetized rats. The responses of STT neurons to mechanical and thermal stimuli and the sensitivity to intravenous morphine were determined in diabetic and normal rats. In 12 diabetic rats, mechanical allodynia and hyperalgesia, but not thermal hyperalgesia, developed within 2 wk after streptozotocin injection and lasted for ≥7 wk. Compared to the 32 STT neurons recorded in normal animals, the 37 STT neurons in diabetic rats displayed a higher spontaneous discharge activity and enlarged receptive fields. Also, the STT neurons in diabetic rats exhibited lower thresholds and augmented responses to mechanical stimulation. Intravenous injection of 2.5 mg/kg of morphine suppressed significantly the responses of STT neurons to noxious stimuli in 12 nondiabetic rats. However, such an inhibitory effect of morphine on the evoked response of STT neurons was diminished in 14 diabetic animals. This electrophysiological study provides new information that development of hypersensitivity of spinal dorsal horn projection neurons may be closely related to neuropathic pain symptoms caused by diabetes. Furthermore, the attenuated inhibitory effects of morphine on evoked responses of STT neurons in diabetes likely accounts for its reduced analgesic efficacy in this clinical form of neuropathic pain.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Jianyu Zhou ◽  
Linyuan Wang ◽  
Jingxia Wang ◽  
Chun Wang ◽  
Zhihui Yang ◽  
...  

Neuropathic pain remains as the most frequent cause of suffering and disability around the world. The isomers paeoniflorin (PF) and albiflorin (AF) are major constituents extracted from the roots ofPaeonia (P.) lactifloraPall. Neuroprotective effect of PF has been demonstrated in animal models of neuropathologies. However, only a few studies are related to the biological activities of AF and no report has been published on analgesic properties of AF about neuropathic pain to date. The aim of this study was to compare the effects of AF and PF against CCI-induced neuropathic pain in rat and explore the underlying mechanism. We had found that both PF and AF could inhibit the activation of p38 mitogen-activated protein kinase (p38 MAPK) pathway in spinal microglia and subsequent upregulated proinflammatory cytokines (interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α)). AF further displayed remarkable effects on inhibiting the activation of astrocytes, suppressing the overelevated expression of phosphorylation of c-Jun N-terminal kinases (p-JNK) in astrocytes, and decreasing the content of chemokine CXCL1 in the spinal cord. These results suggest that both PF and AF are potential therapeutic agents for neuropathic pain, which merit further investigation.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Mao-yin Zhang ◽  
Yue-peng Liu ◽  
Lian-yi Zhang ◽  
Dong-mei Yue ◽  
Dun-yi Qi ◽  
...  

Objective. The present study is to investigate the analgesic roles of L-THP in rats with bone cancer pain caused by tumor cell implantation (TCI).Methods. Thermal hyperalgesia and mechanical allodynia were measured at different time points before and after operation. L-THP (20, 40, and 60 mg/kg) were administrated intragastrically at early phase of postoperation (before pain appearance) and later phase of postoperation (after pain appearance), respectively. The concentrations of TNF-α, IL-1β, and IL-18 in spinal cord were measured by enzyme-linked immunosorbent assay. Western blot was used to test the activation of astrocytes and microglial cells in spinal cord after TCI treatment.Results. TCI treatment induced significant thermal hyperalgesia and mechanical allodynia. Administration of L-THP at high doses significantly prevented and/or reversed bone cancer-related pain behaviors. Besides, TCI-induced activation of microglial cells and the increased levels of TNF-αand IL-18 were inhibited by L-THP administration. However, L-THP failed to affect TCI-induced astrocytes activation and IL-1βincrease.Conclusion. This study suggests the possible clinical utility of L-THP in the treatment of bone cancer pain. The analgesic effects of L-THP on bone cancer pain maybe underlying the inhibition of microglial cells activation and proinflammatory cytokines increase.


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