Minocycline reduces proinflammatory and oxidative stress markers in the spinal cord and morphology changes in sciatic nerve of Type 2 diabetic neuropathy rat model

doi:10.21203/rs.3.rs-4927479/v1

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Minocycline reduces proinflammatory and oxidative stress markers in the spinal cord and morphology changes in sciatic nerve of Type 2 diabetic neuropathy rat model

https://doi.org/10.21203/rs.3.rs-4927479/v1

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Aim: Diabetic neuropathy (DN) is a consequence of prolonged hyperglycemia due to inflammation process in nerve. Minocycline has been shown to act as anti-inflammatory agent but their effects on Type 2 diabetic (T2DM) neuropathy rats’ model are still unclear. This study investigated the effects of minocycline on proinflammatory cytokines and oxidative stress marker levels in the spinal cord and sciatic nerve morphology in T2DM neuropathy rats.

Methods: Male Sprague Dawley rats were randomly assigned to six groups (n=14 per groups): Control (C), T2DM control (STZ), T2DM treated with minocycline 40 mg/kg (STZ+ M40) and 80 mg/kg (STZ + M80), T2DM treated with gabapentin (STZ + G10) and non-painful T2DM neuropathy (NPDN). T2DM was induced in obese rats using a combination of high fat diet (HFD) and low dose streptozotocin (STZ) (40 mg/kg) injection. Then, the neuropathic pain behaviour, body weight and blood biochemical analysis were performed. Rats were sacrificed and the spinal cord and sciatic nerve were collected for ELISA and histology examination.

Results: After 6 weeks treatment with HFD diet, all T2DM rat groups were significantly increased body weight but significantly reduced from 8 until 9 weeks after STZ were injected compared to control group (p<0.05). The fasting blood glucose (FBG) level in all T2DM groups were significantly higher on day 3, day 14, and day 22 of the study compared to control group (p<0.05) consistent with HbA1c levels. T2DM groups also significantly increased MDA, TNF-α, IL-1β and C-Reactive Protein (CRP) but decreased SOD and Catalase levels in the spinal cord compared to control group (p<0.05). T2DM groups also showed significant abnormal histopathological changes in the sciatic nerve compared to control group (p<0.05). Administration of minocycline dependent on doses and gabapentin in T2DM rat significantly alleviated all these effects.

Conclusion: Dependent on dose, minocycline was found to reduce pro-inflammatory cytokines and oxidative stress markers level in the spinal cord and recovery sciatic nerve morphology changes of T2DM neuropathy rats. These findings suggest the neuroprotective effects of minocycline on T2DM neuropathy.

Type 2 diabetic neuropathy

minocycline

biochemical analysis

oxidative stress marker

pro-inflammatory cytokines

sciatic nerve histology

T2DM neuropathy rat increases proinflammatory cytokines and oxidative stress markers level in the spinal cord consistent with abnormal morphology changes in the sciatic nerve morphology.
Minocycline reduced proinflammatory cytokines and oxidative stress markers level in the spinal cord and improves the abnormal morphology changes of sciatic nerve back into normal condition.

Prolong hyperglycemia in diabetes mellitus (DM) contribute to the macrovascular and microvascular consequences to the diabetic patients. Microangiopathy, nephropathy, neuropathy and retinopathy are example of microvascular consequences of DM¹. Diabetic neuropathy (DN) is regarded as one of the most debilitating outcomes of DM and it is estimated that 50% of the diabetic patients develop signs of nerve damage after over 25 years of having DM ². The lesion and dysfunction of the peripheral and central somatosensory nervous system caused neuropathic pain, one type of chronic pain ³. Over one third of patients with DN will develop painful diabetic neuropathy (PDN) ⁴.

Hyperglycemia is a primary pathophysiological factor in the development of PDN. Hyperglycemia can activate some major pathways like polyol pathway ⁵, advanced glycation end products (AGE) ⁶, hexosamine flux ⁷, mitogen-activated protein kinase (MAPK) ⁸ and poly-ADP ribose polymerase (PARP)⁹. The combined impact of these cascades produces intense oxidative stress, cytokine release and neuroinflammation^3,10. Studies have demonstrated that hyperglycaemia in diabetes has activated glial cells (microglia and astrocytes) and released reactive oxygen species (ROS) that cause neurotoxicity, stimulated the release of proinflammatory cytokines and chemokines such as IL-1β, IL-6, tumour necrosis factor-α (TNFα), prostaglandin E2 (PGE2) and nitric oxide ^{11, 10}.

Nerve is made up of a cluster of nerve fibres, each of which contains many neurons. Axons are the elongated portions of the neuron that transmit signals. Schwann cells, the supporting glial cells of the peripheral nervous system produced myelin, which wraps around axons to form a thick myelin sheath. The degeneration and apoptosis of Schwann cell are prominent features of the onset and progression of PDN¹². As previously demonstrated in animal models and human patients, significant neuron damage, as defined by a decrease in nerve fibre density, was detected in PDN sciatic nerve tissues ^{13, 14}.

Many researchers have been drawn to minocycline, a well-established semisynthetic antibiotic from the tetracycline family, due to its potent anti-inflammatory effects in animal models for the treatment of ischaemia¹⁵, Huntington disease¹⁶, Parkinson disease¹⁷, amyotrophic lateral sclerosis¹⁸, and multiple sclerosis ¹¹. Furthermore, minocycline has been demonstrated can decrease neuropathic pain symptoms such as mechanical allodynia and hyperalgesia in PDN model from streptozotocin (STZ)-induced type 1 diabetic (T1DM) rat ^{19, 20}. In our previous studies, we discovered a similar result²¹. Minocycline has been found to have a strong inhibitory effect on microglial activation, which may explain the possible relief of neuropathic pain symptoms, most likely through the suppression of pro-inflammatory cytokines released by activated microglia during the pathogenesis of neuropathic pain ²².

However, most research on rat PDN model used T1DM rat that only develops insulin deficiency rather than insulin resistance that occurs in type 2 diabetes (T2DM) in human. Combination of high fat diet with low dose STZ has been successfully mimicked natural progress of diabetes development as well as metabolic features in T2DM rat model ²³. Whether similar mechanism of PDN in T1DM rat model ^{19,21, 20} can contribute to alteration of pain responses in T2DM rat model are still unclear. Thus, in the present study we investigated the effects of minocycline (microglia activation inhibitor) on proinflammatory cytokines and oxidative stress marker levels in spinal cord and sciatic nerve morphology of PDN in T2DM rat model.

2.1 Animals

The study was performed on eighty-four male Sprague-Dawley (SD) male rats weighing 200 to 230 g (8 to 10 weeks old). The animals were procured from the Animal Research and Service Centre (ARASC) and housed three rats per cage under standard conditions (12 h light/dark cycle, 25°C, 40–60% humidity). The experimental procedures conducted in the present study followed the Animal Ethics Approval (USM/IACUC/2020/ [125] [1101]).

2.2 Induction of type 2 diabetic rat model

After acclimatization, the animals were randomly assigned to one of two groups: treated with normal diet, chow pellet (control group) (n = 14) and treated with high fat diet (HFD) for six weeks, (obese group) (n = 70). Diabetes was developed in obese rats (n = 70) by injecting STZ (40 mg/kg) intraperitoneally. After 72 hours STZ injection, rats with the final blood glucose level ≥ 270 mg/dL were considered as diabetic. Diabetic rats were further divided into four groups: treated with STZ (n = 14), treated STZ with minocycline 40 mg/kg (STZ + M40) and minocycline 80 mg/kg (STZ + M80) intraperitoneal (n = 14 for each groups) ¹⁹, treated STZ with 100 mg/kg gabapentin (STZ + G100) (n = 14) ²⁴. Other rats were set aside for STZ-induced diabetic rats that did not develop PDN and were designated as the non-painful diabetic neuropathy group (NPDN; N = 14). The NPDN was the rat which have less than 15% of reduction in paw withdrawal threshold value by von-Frey test compared from baseline value before the diabetic was induced.

2.3 Fasting blood glucose

Fasting blood glucose (FBG) was measured in the blood obtained from the tail vein using a glucometer (Accu-check Performa, Roche Diagnostics, Paris, France). FBG was measured on day 0 (prior to injection of STZ), day 14 (prior to treatment begin) and day 22 post-injection of STZ or saline. The changes in the body weight of the rats throughout the study period also was recorded.

2.4 Blood serum level of Hba1c, C-Reactive Protein (CRP) and Insulin

After day 22 post-injections of STZ, the rat was sacrificed by decapitation with guillotine ²⁰. The blood sample was collected into a centrifuge tube. After 30 minutes, the blood sample was centrifuged for 5 minutes at 1200 xg at room temperature to collect the serum. The quantification of glycated haemoglobin A1c (HbA1c), C-reactive protein (CRP) and insulin in the rat serum was performed using commercial Rat ELISA test kit (RayBiotech).

2.5 IL-1β, TNF-α and oxidative stress marker level using ELISA

The lumbar enlargement of spinal cord (L5-L6) was collected and then weighted. The homogenates (10% w/v) of spinal cord were centrifuged with speed centrifugation (10,000 x g) for 10 min and the samples was kept at -80 ºC until assay. Proinflammatory cytokines (IL-1β and TNF-α) and oxidative stress markers (SOD, MDA and CAT) were measured using the commercially available ELISA kits (Cayman or Northwest Life Science Specialties, LLC).

2.6 Histopathological analysis of Sciatic Nerve

The rat hind paw sciatic nerve was isolated from surrounding tissues by separating the femoral biceps and gluteal muscles using blunt dissection. The sciatic nerve was taken and stored in 10% formalin for 24 hours. The specimen was dehydrated and placed in xylene for 1 hour (3 times) and later in ethyl alcohol (70%, 90%, and 100%) for 2 hours, respectively. The infiltration and impregnation were carried out by treating with paraffin wax twice, each time for 1 hour. Then, tissue specimens were cut into sections of 3 to 5 mm thickness and stained with haematoxylin and eosin. The specimen was mounted on a slide using mounting medium. Sections was examined under a light microscope (400x) to obtain a general impression of the histopathology features of specimen and infiltration of cells. The various changes in histological features and infiltration of cells were graded as grade 0 (not present); grade 1 (mild); grade 2 (moderate); and grade 3 (severe) ²⁵.

2.7 Statistical Analysis

The results were analysed using SPSS version 24 software. Numerical data was analyzed by descriptive statistics. The data distribution was analyzed using histogram and Kolmogorov-Smirnov test before conducting parametric or non-parametric tests. For this study, two-way repeated measured ANOVA was used to analyse body weight changes and fasting blood glucose level. While one-way repeated measure ANOVA was used to analyse IL-1β, TNF-α, SOD, MDA and catalase levels in the spinal cord and HbA1c, CRP and insulin level in blood serum. Probability values P < 0.05 are considered significant.

3.1 Body weight changes

Two-way repeated measures ANOVA demonstrated that there was a significant effect on body weight between experimental groups (p < 0.05) as shown in Fig. 1A. At 6 weeks after experiment began, all rats in obese groups treated with HFD were showed significant increased body weight compared to control groups (p < 0.05). However, at 8 weeks after experiments began, all this obese groups treated with HFD started showed significantly reduced its body weight compared to control group (p < 0.05), after 1 weeks STZ was injected. This effect continued until 9 weeks after experiment began, when all obese groups treated with HFD had developed into diabetes and showed significant reduced body weight compared to control group (p < 0.05).

3.2 Fasting blood glucose level

The fasting blood glucose changes throughout Day 0, Day 3, Day 14 and Day 22 is depicted in Fig. 1B. Two-way repeated measures ANOVA showed that there was significant difference on fasting blood glucose level between all groups (p < 0.05). The injection of STZ at a dose of 40 mg/kg intraperitoneally into the obese rats treated with HFD resulted in developing T2DM conditions started from day 3 and their FBG was significantly increased when compared to control group (p < 0.05) at days 3, 14 and 22. Administration of treatment with minocycline and gabapentin started at day 15, did not ameliorate the elevated fasting blood glucose in all these T2DM groups when compared to control group (p < 0.05) at day 22.

3.3 HbA1C level

One -way repeated measures ANOVA showed that there was significant difference on HbA1C level between all groups (p < 0.05). The injection of STZ at a dose of 40 mg/kg intraperitoneally into the obese rats treated with HFD resulted in developing T2DM conditions and their HbA1C level was significantly increased when compared to control group (p < 0.05). Administration of treatment with minocycline and gabapentin did not ameliorate the elevated HbA1C level in all these T2DM groups when compared to control group.

3.4 Insulin level

Hyperinsulinemia is one characteristic for T2DM condition. In this study, insulin level in all T2DM groups showed slightly higher compared to control group, however not significantly difference. The insulin level not very much affected in this study may be due to early phase of development to T2DM.

3.5 Pro-inflammatory cytokines (IL-1β, TNF-α) level.

One-way repeated measures ANOVA showed that there was significant difference on pro-inflammatory cytokines (IL-1β, TNF-α) in the spinal cord and inflammation level (CRP) in the blood serum between all groups (p < 0.05). The STZ group was showed significantly increased on IL-1β and TNF-α levels in their spinal cord when compared to control group (p < 0.05). Administration of treatment with minocycline (STZ + M40, STZ + M80) and gabapentin (STZ + G100) significantly alleviate the increased IL-1β and TNF-α level in spinal cord when compared to STZ group (p < 0.05). Similar like upregulation of IL-1β and TNF-α, CRP level in blood serum also was significantly increased in STZ group compared to control group (p < 0.001). The high level of CRP in STZ group was alleviated by administration of minocycline and gabapentin. CRP level in STZ + M40, STZ + M80 and STZ + G100 were significantly decreased compared to STZ group (p < 0.001) as showed in Fig. 2.

3.6 Oxidative stress level

One-way repeated measures ANOVA showed that there was significant difference on oxidant (MDA) and antioxidant (SOD, CAT) levels in the spinal cord between all groups (p < 0.05). The STZ group was showed significantly increased on MDA (p < 0.05) but decreased SOD and CAT levels (p < 0.05) in their spinal cord when compared to control group. Administration of treatment with minocycline (STZ + M80) and gabapentin (STZ + G100) significantly reduced the MDA level (p < 0.05) and increased SOD and CAT levels (p < 0.05) compared to STZ group. Whereas NPDN group showed similar effects like STZ group on MDA, SOD and CAT level in their spinal cord.

3.7 Morphological features of T2DM rats

Figure 4 and Table 1 showed the morphology of sciatic nerve from control group with features like absence of infiltration of inflammatory cells and necrosis of nerve. Nerve fibres were also closely packed. Intraperitoneal administration of STZ resulted in significant morphological changes assessed in cross-sectional section of sciatic nerve of STZ group. It showed the presence of inflammatory cells and edema in the nerve cells. It also showed the necrosis in the nerve cell with vacuolization which results in loss and swelling of nerve fibres. Administration of minocycline (40 and 80 mg/kg) for 1 weeks resulted in reduction of inflammatory cells infiltration, edema, necrosis and vacuolation in sciatic nerve. Gabapentin (100 mg/kg) treated group showed the similar kind of attenuated in morphological changes that were associated with the STZ-induced diabetic neuropathy. While NPDN group showed obvious morphological alteration after STZ administration similar like STZ group.

Table 1

The scores for morphological changes on sciatic nerve of control and T2DM neuropathy rats treated with minocycline and gabapentin.
	Infiltration of inflammatory cell	edema	Necrotic change in nerve	Nerve vacuolation
Control	-	+	-	-
STZ	+++ ^a	+++ ^a	+++ ^a	+++ ^a
STZ + M40	+++^a	+++ ^a	+++ ^a	++ ^a
STZ + M80	+ ^{a, b, c}	+ ^{a, b}	+ ^{a, c}	+ ^{a, b, c}
STZ + G100	+ ^{a, b, c}	+^b	+^c	+ ^{a, b, c}
NPDN	+++ ^{a, d, e}	+++ ^a	+++ ^{a, d, e}	+++ ^{a, d, e}
STZ: Streptozotocin, M: minocycline, G: gabapentin, NPDN: non painful diabetic neuropathy. ^ap<0.05 vs. control group; ^bp<0.05 vs. STZ group, ^cp<0.05 vs. STZ + M40 group, ^dp<0.05 vs. STZ + M80 group, ^ep<0.05 vs. STZ + G100 group. +, severity.

In this study, we induced the T2DM rat model by being given a high fat diet for six weeks. At 6 weeks all rats in this HFD had increased their body weight compared to the control group. However, when we started to induce diabetes by injecting streptozotocin (40 mg/kg) at 8 weeks, the body weight of all this HFD group was significantly reduced compared to control group. The reduced body weight was consistent until the end of experimentation which is at 9 weeks. This effect is consisted with other studies, showed that rats given HFD can increased their body weight and after injected with STZ, the rats were reduced their body weight, which is characteristic of development into T2DM ²⁶^,²⁷. The reduced body weight in diabetic animals may be attributed to the metabolic disorder associated with diabetes. Study has been reported that diabetes induced oxidative stress led to partial destruction of insulin β cells and insulin deficiency that caused an extravagant breakdown of tissue proteins causing he observed in bodyweight that was associated with wasting muscle mass ²⁸. However, the minocycline and gabapentin treatments given in this study showed no changes in body weight. Body weight in NPDN group showed a reduced pattern compared to control group, similar with others HFD groups that turn to T2DM.

After injected with STZ, the blood glucose level started to increase in all HFD groups (STZ, STZ+M40, STZ+M80, STZ+G100) compared to control group at 14 and 22 days of experiments. Whereas, in NPDN group, there was increased in blood glucose level but not as higher as compared to all HFD groups that develop into T2DM. Treatment with minocycline and gabapentin did not ameliorate the increased blood glucose level in these groups. The higher HbA1c level in all HFD groups (STZ, STZ +M40, STZ + M80, STZ+G100) compared to control group, is the evidence to confirm that all these groups had developed into T2DM. Their insulin level was not drastically reduced if compared to control group, but seemly similar or even higher compared to control group. This could be due to the early development of T2DM in these groups. Hyperinsulinemia is one of the characteristics of insulin resistance which occurred in T2DM, in contrast to hypoinsulinemia condition that usually occurred in T1DM. Therefore, we could suggest that the model for T2DM had been successfully developed in this study by modified the diet. Interesting, NPDN group also got similar characteristics with these T2DM groups, except their blood glucose level not increased as much as others T2DM groups.

Studies have shown that persistent hyperglycemia can increased the level of oxidative stress markers and reduced antioxidants levels at the spinal cord of T1DM rat ¹⁹^, ²¹. This effect is consistent with this study, when STZ group showed increased in their spinal cord MDA levels but reduced the SOD and Catalase levels. Treatment with minocycline and gabapentin can alleviate this effect. The MDA level at spinal cord of STZ + M40, STZ + M80 and STZ +G100 groups significantly reduced, whereas SOD and Catalase level of these groups significantly increased when compared to control group. This effect is consistent with other studies that showed, minocycline can reduce oxidative marker and elevated the antioxidant level in various tissues due to many diseases such as neurodegenerative ²⁹^, ³⁰ and also diabetes ²¹^,¹⁹. The changes of oxidative and anti-oxidant markers levels in NPDN group looked similar with the STZ group.

In this study, we found that there is upregulation of the inflammation process in the spinal cord of T2DM group (STZ group) compared to other groups. Serum C-reactive protein, TNF-α and IL-1β levels in the spinal cord, which are the markers for inflammation have been increased in STZ group. Administration of minocycline and gabapentin successfully ameliorate these effects. Serum CRP, TNF-α and IL-1β levels in the spinal cord of the STZ +M40, STZ + M80 and STZ + G100 groups significantly reduced compared to STZ group (Figure 3). Many studies have showed that during diabetes condition, there is increases in the proinflammatory mediators in our tissues like spinal cord and brain ⁹^,²¹^, ²⁰. Similar like T2DM (STZ groups), Serum CRP, TNF-α and IL-1β levels in the spinal cord of NPDN groups is also upregulated in similar pattern.

Increases in oxidative stress marker and higher inflammatory mediators in T2DM (STZ group) seem to affect the morphology of sciatic nerve. Study has shown that diabetic rats also have elevated oxidative stress markers and proinflammatory cytokines in sciatic nerve ³¹ . The sciatic nerve of STZ group in this study increased with the infiltration of inflammatory cells like eosinophil and neutrophil. The cell also became necrotic and filled with vacuolation and it also found that edema has occurred. Treatment with minocycline especially higher dose (80 mg/kg) and gabapentin ameliorate these morphological changes in sciatic nerve. There is reduced the infiltration of inflammatory cells, necrotic and vacuolation in the cells and edema also less occurred in STZ + M80 and STZ+ G100 groups compared to other groups. Studies have been reported the morphological changes of sciatic nerve in diabetic patient and animals model ³²^, ³³^, ¹³. However, it is not sure whether minocycline and gabapentin ameliorate these morphological changes in sciatic nerve through downregulated the oxidative stress markers and proinflammatory cytokines level, since the level of these factors not measured on the sciatic nerve. However, we believe that downregulation of oxidative stress markers and proinflammatory cytokines level in the spinal cord after minocycline and gabapentin could also give similar effect on the sciatic nerve of diabetic rats in this study.

As conclusion, minocycline has potential to be use as symptomatic PDN treatment. However, the modulation of minocycline on the oxidative stress markers, proinflammatory cytokines in the spinal cord and degeneration of sciatic nerve and the relation to the pain behaviour responses and the signalling pathways that involved or activated during this process in T2DM rat model induced PDN still unclear and need further investigation.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest concerning the research, authorship, and/or publication of this article.

Acknowledgment

This study was supported by Fundamental Research Grant Scheme (FRGS) Ministry of Higher Education Malaysia (FRGS/1/2020/SKK0/USM/03/5).

Author Contribution

NAH and IL analysed and wrote the main manuscript text, prepared figures 1-4 and table 1. NSO, CAN, IL reviewed the manuscript.

Kharroubi AT. Diabetes mellitus: The epidemic of the century. World J Diabetes. 2015;6(6):850. doi:10.4239/wjd.v6.i6.850
Feldman EL, Nave KA, Jensen TS, Bennett DLH. New Horizons in Diabetic Neuropathy: Mechanisms, Bioenergetics, and Pain. Neuron. 2017;93(6):1296-1313. doi:10.1016/j.neuron.2017.02.005
Calcutt NA. Diabetic Neuropathy and Neuropathic Pain: A (CoN) Fusion of Pathogenic Mechanisms? Vol 161.; 2020. doi:10.1097/j.pain.0000000000001922
Yang H, Sloan G, Ye Y, Wang S, Duan B, Tesfaye S, et al. New Perspective in Diabetic Neuropathy: From the Periphery to the Brain, a Call for Early Detection, and Precision Medicine. Front Endocrinol (Lausanne). 2020;10(January):1-13. doi:10.3389/fendo.2019.00929
Ramana K V. Aldose reductase: New insights for an old enzyme. Biomol Concepts. 2011;2(1-2):103-114. doi:10.1515/bmc.2011.002
Puddu A, Sanguineti R, Durante A, Nicolò M, Viviani GL. Vascular endothelial growth factor-C secretion is increased by advanced glycation end-products: Possible implication in ocular neovascularization. Mol Vis. 2012;18(October):2509-2517.
Brownlee M. Biology of Diabetic Complications. Nature. 2001;414(December):813-820.
Lim AKH, Ma FY, Nikolic-Paterson DJ, Ozols E, Young MJ, Bennett BL, et al. Evaluation of JNK blockade as an early intervention treatment for type 1 diabetic nephropathy in hypertensive rats. Am J Nephrol. 2011;34(4):337-346. doi:10.1159/000331058
Abdelkader NF, Ibrahim SM, Moustafa PE, Elbaset MA. Inosine mitigated diabetic peripheral neuropathy via modulating GLO1/AGEs/RAGE/NF-κB/Nrf2 and TGF-β/PKC/TRPV1 signaling pathways. Biomed Pharmacother. 2022;145(August 2021):112395. doi:10.1016/j.biopha.2021.112395
Ab Hamid N, Omar N, Ismail CAN, Long I. Insight of Mechanism and Signaling Pathway in Pathogenesis of Diabetic Neuropathy: A Review. IIUM Med J Malaysia. 2021;20(4):95-103. doi:10.31436/imjm.v20i4.1947
Zhao H, Alam A, Chen Q, Eusman MA, Pal A, Eguchi S, et al. The role of microglia in the pathobiology of neuropathic pain development: What do we know? Br J Anaesth. 2017;118(4):504-516. doi:10.1093/bja/aex006
Zhang X, Liang Z, Zhou Y, Wang F, Wei S, Tan B, et al. Artesunate Inhibits Apoptosis and Promotes Survival in Schwann Cells via the PI3K/AKT/mTOR Axis in Diabetic Peripheral Neuropathy. Biol Pharm Bull. 2023;46(6):764-772. doi:10.1248/BPB.B22-00619
Jende JME, Kender Z, Mooshage C, Groener JB, Alvarez-Ramos L, Kollmer J, et al. Diffusion Tensor Imaging of the Sciatic Nerve as a Surrogate Marker for Nerve Functionality of the Upper and Lower Limb in Patients With Diabetes and Prediabetes. Front Neurosci. 2021;15(March):1-11. doi:10.3389/fnins.2021.642589
Colcimen N, Altindag F. Evaluation of the effects of sinapic acid and ellagic acid on sciatic nerve in experimental diabetic rats by immunohistochemical and stereological methods. J Chem Neuroanat. 2023;131(January):102274. doi:10.1016/j.jchemneu.2023.102274
Lechpammer M, Manning SM, Samonte F, Nelligan J, Sabot E, Talos DM, et al. Minocycline treatment following hypoxic/ischaemic injury attenuates white matter injury in a rodent model of periventricular leucomalacia. Neuropathol Appl Neurobiol. 2008;34(4):379-393. doi:10.1111/j.1365-2990.2007.00925.x
Cudkowicz M. A futility study of minocycline in huntington’s disease. Mov Disord. 2010;25(13):2219-2224. doi:10.1002/mds.23236
Diguet E, Fernagut PO, Wei X, Du Y, Rouland R, Gross C, et al. Deleterious effects of minocycline in animal models of Parkinson’s disease and Huntington’s disease. Eur J Neurosci. 2004;19(12):3266-3276. doi:10.1111/j.0953-816X.2004.03372.x
Metz LM, Li DKB, Traboulsee AL, Duquette P, Eliasziw M, Cerchiaro G, et al. Trial of Minocycline in a Clinically Isolated Syndrome of Multiple Sclerosis. N Engl J Med. 2017;376(22):2122-2133. doi:10.1056/nejmoa1608889
Pabreja K, Dua K, Sharma S, Padi SSV, Kulkarni SK. Minocycline attenuates the development of diabetic neuropathic pain: Possible anti-inflammatory and anti-oxidant mechanisms. Eur J Pharmacol. 2011;661(1-3):15-21. doi:10.1016/j.ejphar.2011.04.014
Ismail CAN, Suppian R, Aziz CBA, Long I. Minocycline attenuates the development of diabetic neuropathy by modulating DREAM and BDNF protein expression in rat spinal cord. J Diabetes Metab Disord. 2019;18(1):181-190. doi:10.1007/s40200-019-00411-4
Ismail CAN, Aziz CBA, Suppian R, Long I. Imbalanced oxidative stress and pro-inflammatory markers differentiate the development of diabetic neuropathy variants in streptozotocin-induced diabetic rats. J Diabetes Metab Disord. 2018;17(2):129-136. doi:10.1007/s40200-018-0350-x
Tsuda M. Microglia in the spinal cord and neuropathic pain. J Diabetes Investig. 2016;7(1):17-26. doi:10.1111/jdi.12379
Azemi AK, Mokhtar SS, Rasool AHG. Clinacanthus nutans Leaves Extract Reverts Endothelial Dysfunction in Type 2 Diabetes Rats by Improving Protein Expression of eNOS. Oxid Med Cell Longev. 2020;2020. doi:10.1155/2020/7572892
Barragán-Iglesias P, Oidor-Chan VH, Loeza-Alcocer E, Pineda-Farias JB, Velazquez-Lagunas I, Salinas-Abarca AB, et al. Evaluation of the neonatal streptozotocin model of diabetes in rats: Evidence for a model of neuropathic pain. Pharmacol Reports. 2018;70(2):294-303. doi:10.1016/j.pharep.2017.09.002
Kandhare AD, Raygude KS, Shiva Kumar V, Rajmane AR, Visnagri A, Ghule AE, et al. Ameliorative effects quercetin against impaired motor nerve function, inflammatory mediators and apoptosis in neonatal streptozotocin-induced diabetic neuropathy in rats. Biomed Aging Pathol. 2012;2(4):173-186. doi:10.1016/j.biomag.2012.10.002
Ishak NA, Ismail M, Hamid M, Ahmad Z, Abd Ghafar SA. Antidiabetic and hypolipidemic activities of Curculigo latifolia fruit:Root extract in high fat fed diet and low dose STZ induced diabetic rats. Evidence-based Complement Altern Med. 2013;2013. doi:10.1155/2013/601838
Azemi AK, Mokhtar SS, Rasool AHG. Clinacanthus nutans Leaves Extract Reverts Endothelial Dysfunction in Type 2 Diabetes Rats by Improving Protein Expression of eNOS. Lillig CH, ed. Oxid Med Cell Longev. 2020;2020:7572892. doi:10.1155/2020/7572892
Balamurugan R, Ignacimuthu S. Antidiabetic and hypolipidemic effect of methanol extract of Lippia nodiflora L. in streptozotocin induced diabetic rats. Asian Pac J Trop Biomed. 2011;1(SUPPL. 1). doi:10.1016/S2221-1691(11)60117-2
Abdo Qaid EY, Abdullah Z, Zakaria R, Long I. Minocycline protects against lipopolysaccharide-induced glial cells activation and oxidative stress damage in the medial prefrontal cortex (mPFC) of the rat. Int J Neurosci. 2022;0(0):1-10. doi:10.1080/00207454.2022.2084092
Qaid EYA, Abdullah Z, Zakaria R, Long I. Minocycline Protects Against Lipopolysaccharide-Induced Cognitive Impairment and Oxidative Stress: Possible Role of the CREB-BDNF Signaling Pathway. Neurochem Res. 2023;48(5):1480-1490. doi:10.1007/s11064-022-03842-3
Arisha S. Sciatic Histological, Ultrastructural and Biochemical Investigations on Improving the Effect of Pregabalin by Flaxseed Oil on Diabetic Peripheral Neuropathy Induced in Albino Rats. Egypt Acad J Biol Sci D Histol Histochem. 2022;14(2):85-103. doi:10.21608/eajbsd.2022.267166
Wright A, Nukada H. Sciatic nerve morphology and morphometry in mature rats with streptozocin-induced diabetes. Acta Neuropathol. 1994;88(6):571-578. doi:10.1007/BF00296495
Srilatha K, Reddy KP. Sciatic Nerve Structural and Functional Recovery with Extract of Phyllanthus amarus and Esculetin in STZ-Induced Hyperglycemic Rats. Ann Neurosci. 2019;26(3-4):17-29. doi:10.1177/0972753120911840

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Minocycline reduces proinflammatory and oxidative stress markers in the spinal cord and morphology changes in sciatic nerve of Type 2 diabetic neuropathy rat model

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Abstract

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1. Introduction

2. Methods

2.1 Animals

2.2 Induction of type 2 diabetic rat model

2.3 Fasting blood glucose

2.4 Blood serum level of Hba1c, C-Reactive Protein (CRP) and Insulin

2.5 IL-1β, TNF-α and oxidative stress marker level using ELISA

2.6 Histopathological analysis of Sciatic Nerve

2.7 Statistical Analysis

3. Results

3.1 Body weight changes

3.2 Fasting blood glucose level

3.3 HbA1C level

3.4 Insulin level

3.5 Pro-inflammatory cytokines (IL-1β, TNF-α) level.

3.6 Oxidative stress level

3.7 Morphological features of T2DM rats

4. Discussion

Declarations

References

Additional Declarations

Status:

Version 1