The protective effect of the active components of ERPC on diabetic peripheral neuropathy in rats

Advances of traditional Chinese medicine preclinical mechanisms and clinical studies on diabetic peripheral neuropathy

CONTEXT

Diabetic peripheral neuropathy (DPN) results in an enormous burden and reduces the quality of life for patients. Considering there is no specific drug for the management of DPN, traditional Chinese medicine (TCM) has increasingly drawn attention of clinicians and researchers around the world due to its characteristics of multiple targets, active components, and exemplary safety.

OBJECTIVE

To summarize the current status of TCM in the treatment of DPN and provide directions for novel drug development, the clinical effects and potential mechanisms of TCM used in treating DPN were comprehensively reviewed.

METHODS

Existing evidence on TCM interventions for DPN was screened from databases such as PubMed, the Cochrane Neuromuscular Disease Group Specialized Register (CENTRAL), and the Chinese National Knowledge Infrastructure Database (CNKI). The focus was on summarizing and analyzing representative preclinical and clinical TCM studies published before 2023.

RESULTS

This review identified the ameliorative effects of about 22 single herbal extracts, more than 30 herbal compound prescriptions, and four Chinese patent medicines on DPN in preclinical and clinical research. The latest advances in the mechanism highlight that TCM exerts its beneficial effects on DPN by inhibiting inflammation, oxidative stress and apoptosis, endoplasmic reticulum stress and improving mitochondrial function.

CONCLUSIONS

TCM has shown the power latent capacity in treating DPN. It is proposed that more large-scale and multi-center randomized controlled clinical trials and fundamental experiments should be conducted to further verify these findings.

Functional and structural neurodegenerative activities of Ankaferd BloodStopper in a mouse sciatic nerve model

Traumatic and postoperative hemorrhages are life-threatening complications. Ankaferd BloodStopper (ABS) is a potent topical hemostatic agent to stop bleeding. However, ABS is associated with nerve toxicity. The present study aimed to investigate the functional and structural neurodegenerative effects of ABS in a mouse model. A total of 30 male BALB/c mice, aged 6-8 weeks, were randomly divided into control group (no treatment), a sham group (treated with saline) and an experimental group (treated with ABS). In the saline and the ABS groups, the right sciatic nerve was surgically exposed and treated with saline or ABS, respectively. No surgical procedure was performed in the control group. On day 7 post-treatment, functional changes of the sciatic nerve were evaluated by a horizontal ladder rung walking task. Structural changes were assessed with immunohistochemistry. In the horizontal ladder rung walking test, the gait impairment was proportional to the severity of sciatic nerve damage, with the ABS group showing a significantly higher rate of errors than the control and saline groups. Immunohistochemistry demonstrated extensive degeneration and deformation in the axons and myelin sheath of the sciatic nerve in the ABS group. The results provide compelling evidence for the neurotoxicity of ABS.

Transcriptome Profiling of miRNA-mRNA Interactions and Associated Mechanisms in Chemotherapy-Induced Neuropathic Pain

Chemotherapy-induced neuropathic pain (CINP) is a dose-limiting adverse event affecting 40% of chemotherapy patients. MiRNA-mRNA interaction plays an important role in various processes. However, detailed profiling of miRNA-mRNA interactions in CINP remains unclear. Here, a rat-based CINP model was established using paclitaxel, followed by nociceptive behavioral tests related to mechanical allodynia, thermal hyperalgesia, and cold allodynia. The landscape of miRNA-mRNA interaction in the spinal dorsal horn was investigated through mRNA transcriptomics and small RNA sequencing. Under CINP condition, 86 differentially expressed mRNAs and 56 miRNAs were identified. Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses indicated the activity of Odorant binding, postsynaptic specialization and synaptic density, extracellular matrix, mitochondrial matrix, retrograde endocannabinoid signaling, and GTPase activity. Protein-protein interaction (PPI), networks of circRNA-miRNA-mRNA, lncRNA-miRNA-mRNA, and TF-genes were demonstrated. We next explored the immune infiltration microenvironment and found a higher infiltration abundance of Th17 and a lower abundance of MDSC in CINP. RT-qPCR and dual-luciferase assays were used to verify the sequencing results, and single-cell analysis based on the SekSeeq database was conducted. Combined with bioinformatics analyses and experimental validations, Mpz, a protein-coding gene specifically expressed in Schwann cells, was found critical in maintaining CINP under miRNA regulation. Therefore, these data highlight the expression patterns of miRNA-mRNA, and the underlying mechanism in the spinal dorsal horn under CINP condition, and Mpz may serve as a promising therapeutic target for patients with CINP.

Analgesic and neuroprotective effects of Baimai Ointment on diabetic peripheral neuropathy

ETHNOPHARMACOLOGY RELEVANCE

Baimai (BM) ointment, a traditional Tibetan medicine, has been widely used to treat "white vein" disease, paralysis, hemiplegia and claudication caused by trauma, because of its great effects on muscle stretching and collateral activation. As one of the most terrible complications in diabetes patients, diabetes peripheral neuropathy (DPN) is mainly manifested as abnormal pain or numbness in extremities. However, whether BM ointment is a potential drug for DPN treatment is unclear.

AIMS OF THE STUDY

The aim of this study was to investigate the therapeutic effects of BM on DPN in a high-fat diet/low-dose of streptozotocin induced type 2 diabetes rat model and explore underlying mechanisms.

METHODS

The chemical components of BM were determined by high performance liquid chromatography (HPLC), and the possible targets and related pathways candidates involved in the effects of BM on DPN were predicted using network pharmacology methods. Next, the effects of different doses (1.5, 3.0 and 6.0 g/kg) of BM on physiological changes, pain behaviors, motor nerve conduction velocity (MNCV) in DPN rats were assessed and compared with placebo- and mecobalamine (Meco)-treated DPN controls. Then, the effects of BM on the expression of pain associated genes as well as the phosphorylation of PI3K/AKT and MAPKs pathways in DRG of DPN rats were examined.

RESULTS

Through HPLC analysis, curcumin was identified as one of the primary contents of BM. The information from network pharmacology indicated a series of target candidates for BM including IL6, IL10, TNF, CCL2, CXCL12, EGF, VEGFA, BDNF, TGFβ1 and TNF, as well as PI3K-AKT and MAPK signaling pathways. Topical treatment of BM significantly improved the hypersensitivity of mechanical and thermal pain, MNCV and the morphological changes and demyelination of sciatic nerve fibers, without affecting the body weight, serum metabolism or blood glucose. The up-regulated levels of neuropeptides Cgrp, Sst, Sp and chemokines Ccl2 and Ccl3 along with the abnormal expression of p-P38, p-ERK and p-AKT in the DRG of DPN rats were alleviated by BM application.

CONCLUSION

BM ointment has great activities in relieving pain hypersensitivity, neuroprotecting peripheral nerves damage caused by DPN, which may be related to the inhibition of related neuropeptide (Cgrp, Sst, Sp) and chemokine (Ccl2, Ccl3) expression and the regulation of PI3K/AKT and MAPKs signaling pathways in DRG.

BuqiTongluo Granule for Ischemic Stroke, Stable Angina Pectoris, Diabetic Peripheral Neuropathy with Qi Deficiency and Blood Stasis Syndrome: Rationale and Novel Basket Design

Background: BuqiTongluo (BQTL) granules are herbal phenotypic drugs for Qi deficiency and blood stasis (QDBS) syndrome. Its discovery relied primarily on knowledge of observable phenotypic changes associated with diseases. Although BQTL granules have been widely advocated by Chinese Medicine (CM) practitioners, its use lacks empirical support.

Aim of the study: In this basket trial, the efficacy of BQTL granules in multiple diseases that have the QDBS syndrome in common will be compared with placebo.

Materials and Methods: The BuqiTongluo granule for Qi deficiency and blood stasis syndrome (BOSS) study is a basket herbal trial (ClinicalTrials.gov, NCT04408261). It will be a double-blinded, randomized, placebo-controlled, parallel, multicenter, clinical trial. In total, 432 patients (1:1:1 ischemic stroke, stable angina pectoris, and diabetic peripheral neuropathy), who meet the operationalized diagnostic criteria for QDBS syndrome, have been recruited and randomized in a ratio of 1:1 to receive 6 weeks’ treatment with BQTL granules or placebo. The primary outcome is the change in the QDBS syndrome score at week 6 from baseline. Secondary outcomes include objective outcome measures for the three diseases and adverse events. Omics will help to understand these responses by molecular events.

Conclusion: QDBS syndrome is a common phenotypic marker that was hypothesized to predict whether patients with multiple diseases would respond to this targeted therapy. No previous basket trial has assessed the potential efficacy of an herbal intervention for multiple diseases. The unique promise of the trial is its ability to exploit a disease phenotype to discover novel treatments for three diseases for which the root cause is unknown, complex, or multifactorial, and for which scientific understanding is insufficient to provide valid molecular targets.

HuoXue JieDu formula improves diabetic retinopathy in rats by regulating microRNAs

ETHNOPHARMACOLOGICAL RELEVANCE

HuoXue JieDu Formula (HXJDF) originates from classical formulas and was formed based on clinical experience. It is composed of Euonymus alatus (Thunb.) Siebold, Panax notoginseng (Burkill) F.H. Chen, the roots of Anguina kirilowii (Maxim.) Kuntze, and Coptis omeiensis (C. Chen) C.Y.Cheng. HXJDF prevents the deterioration of diabetic retinopathy.

AIM OF THE STUDY

To evaluate the effects of HXJDF on diabetic retinopathy in rats and investigate the roles of miRNAs in the effects of HXJDF.

MATERIALS AND METHODS

A single intraperitoneal injection of streptozotocin (STZ) (65 mg/kg) was used to induce diabetes in rats. Rats were divided into three groups: normal, diabetic, and diabetic + HXJDF. Rats were treated with HXJDF (15.4 g/kg) or water by oral gavage for twelve weeks. At the end of the treatment, rats were anaesthetized, and retinal haemodynamic changes were measured. Then, the retinas were removed and examined by haematoxylin and eosin (HE) staining and TUNEL assays. In addition, miRNA expression profiling was performed using miRNA microarrays and further validated by quantitative real-time PCR (qRT-PCR).

RESULTS

Diabetes reduced peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV) and central retinal vein velocity (CRV) but increased the resistance index (RI) and pulsatility index (PI). In addition, in the diabetic group, retinal cell arrangement was disordered and loosely arranged, the retinal thickness and retinal ganglion cell (RGC) number decreased, and retinal cell apoptosis increased. In addition, 11 miRNAs were upregulated and 4 miRNAs were downregulated. After treatment, HXJDF improved retinal haemodynamics and morphologic changes, restored retinal thickness and RGC number and decreased retinal cell apoptosis. Furthermore, the changes in miRNA expression were significantly abolished by HXJDF.

CONCLUSION

HXJDF may prevent DR by regulating the expression of miRNAs.

Diabetes and plant-derived natural products: From ethnopharmacological approaches to their potential for modern drug discovery and development

Diabetes is a disease of serious concern faced by the health care industry today. Primary diabetes mellitus and its complications are still costly to manage with modern drugs. Extensive research on the screening of anti-diabetic agents in past decades established natural products as one of the major potential sources of drug discovery. However, only a few drugs of plant origin have been scientifically validated. Therefore, the development of new anti-diabetic drugs is of great demand. Hence, natural products could be explored as potential anti-diabetic drugs. Natural plants derived extracts and molecules like berberine, ginsenosides, curcumin, stevioside, gingerols, capsaicin, catechins, simple phenolic compounds, anthocyanins, resveratrol, genistein and hesperidin obtained from different species are used for curing diabetes and found to possess different action mechanisms. In this review, the importance of medicinal plants and their active constituents for anti-diabetic agents are described. The present study also emphasized the importance of diabetes control, reduction in its complications and use of the anti-diabetic agents. The detailed action mechanism of these extracts/compounds for their activities are also described. However, the anti-diabetic drugs from plant origin require scientific validation through animal and clinical studies to exploit in terms of modern commercial medicines.

Berberine restored nitrergic and adrenergic function in mesenteric and iliac arteries from streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Perivascular neuropathy was reported to involve in the vascular disorders associated with diabetes. The dried rhizomes of Coptis chinensis Franch. (Latin name: Coptidis Rhizoma; common name: Huang Lian in China), used frequently in Traditional Chinese medicine to treat diabetes (Xiaoke), have been confirmed to possess beneficial effects on diabetic peripheral neuropathy by modern clinical and pharmacological studies. Berberine (BBR), the main effective component of Huang Lian in the treatment of diabetes, is reported to ameliorate diabetic central and peripheral neuropathy. However, the effects of BBR on nerve function of mesenteric and iliac arteries are unclear.

AIM OF THE STUDY

To investigate the effects of BBR on the diabetes-induced changes in nitrergic and adrenergic function in mesenteric and iliac arteries.

MATERIALS AND METHODS

In this study, the animals were randomized into three groups: control rats, diabetic rats, and diabetic rats gavaged with BBR. We established diabetic rat model using intraperitoneal injection of streptozotocin (STZ, 55 mg kg^-1). Two weeks after model establishment, those in the BBR-treated groups were gavaged with berberine chloride (Sichuan Xieli Fharmaceutical. Co., Ltd; 200 mg·kg^-1·day^-1) diluted in distilled water for another 2 weeks. The superior mesenteric artery and iliac artery were excised. Electric field stimulation (EFS) was used to induce arterial vasoconstriction and explore (1) the diabetes-induced changes in neurogenic function of the superior mesenteric artery and iliac artery; (2) the effects of BBR on neurovascular dysfunction in the early stage of STZ-induced diabetic rats. Nitric oxide (NO) and noradrenaline (NA) released from the nitrergic and adrenergic nerves were quantified using fluorescence assays and ELISA, respectively.

RESULTS

EFS induced frequency-dependent vasoconstrictions in both superior mesenteric and iliac artery, and the contractile responses of arteries were abolished by 0.1 μmol·L^-1 tetrodotoxin (TTX), or inhibited by 1 μmol·L^-1 phentolamine or increased by 0.1 mmol·L^-1 N^ω-Nitro-L-arginine methyl ester hydrochloride (L-NAME). In superior mesenteric artery, but not in iliac artery, the changes of contractile responses with L-NAME were significantly decreased in diabetic rats, and NO release was less also. In contrast, in iliac artery of diabetic rats, but not in superior mesenteric artery, the changes of contractile responses with phentolamine were increased, and NA release was increased significantly. All these changes in diabetic rats on both superior mesenteric artery and iliac artery were reversed by treated with BBR.

CONCLUSIONS

In the STZ-induced early diabetic rats, neural control of mesenteric and iliac vasomotor tone are altered differently. The diminished nitrergic nerve in superior mesenteric artery and enhanced adrenergic nerve in iliac artery both contributed to increased vasocontrictor responses. All these changes in diabetic rats were reversed by BBR, suggesting a novel mechanism of BBR in balance of neural regulation of vascular tone.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

Microarray analyses of lncRNAs and mRNAs expression profiling associated with diabetic peripheral neuropathy in rats

Diabetic peripheral neuropathy (DPN) is considered to be the most frequent neuropathic complication of diabetes, and severely affects the quality of life of patients. Long noncoding RNAs (lncRNAs) participate in various pathophysiological processes and associate with many diseases. However, the exact impact of lncRNAs on DPN remains obscure. To discover a potential connection, a microarray study was conducted to analyze the expression profiling of lncRNAs and messenger RNAs (mRNAs) in dorsal root ganglia (DRG) from streptozotocin-induced diabetic rats with DPN. As a result, 983 lncRNAs and 1357 mRNAs were aberrantly expressed compared with control samples. Using bioinformatics analyses, we identified 558 Gene Ontology terms and 94 Kyoto Encyclopedia of Genes and Genomes pathways to be significantly enriched. Additionally, the signal-net analysis indicated that integrin receptors, including Itgb3, Itgb1, Itgb8, and Itga6, might be important players in network regulation. Furthermore, the lncRNA-mRNA network analysis showed dynamic interactions between the dysregulated lncRNAs and mRNAs. This is the first study to present an overview of lncRNA and mRNA expressions in DRG tissues from DPN rats. Our results indicate that these differentially expressed lncRNAs may have crucial roles in pathological processes of DPN by regulating their coexpressed mRNAs. The data may provide novel targets for future studies, which should focus on validating their roles in the progression of DPN.

Comprehensive analysis of differentially expressed microRNAs and mRNAs in dorsal root ganglia from streptozotocin-induced diabetic rats

Diabetic peripheral neuropathy is a common complication associated with diabetes mellitus with a pathogenesis that is incompletely understood. By regulating RNA silencing and post-transcriptional gene expression, microRNAs participate in various biological processes and human diseases. However, the relationship between microRNAs and the progress of diabetic peripheral neuropathy still lacks a thorough exploration. Here we used microarray microRNA and mRNA expression profiling to analyze the microRNAs and mRNAs which are aberrantly expressed in dorsal root ganglia from streptozotocin-induced diabetic rats. We found that 37 microRNAs and 1357 mRNAs were differentially expressed in comparison to non-diabetic samples. Bioinformatics analysis indicated that 399 gene ontology terms and 29 Kyoto Encyclopedia of Genes and Genomes pathways were significantly enriched in diabetic rats. Additionally, a microRNA-gene network evaluation identified rno-miR-330-5p, rno-miR-17-1-3p and rno-miR-346 as important players for network regulation. Finally, quantitative real-time polymerase chain reaction analysis was used to confirm the microarray results. In conclusion, this study provides a systematic perspective of microRNA and mRNA expression in dorsal root ganglia from diabetic rats, and suggests that dysregulated microRNAs and mRNAs may be important promotors of peripheral neuropathy. Our results may be the underlying framework of future studies regarding the effect of the aberrantly expressed genes on the pathophysiology of diabetic peripheral neuropathy.

Electrophysiological measurements of diabetic peripheral neuropathy: A systematic review

INTRODUCTION

Peripheral neuropathy is one of the main complications of diabetes mellitus. One of the features of diabetic nerve damage is abnormality of sensory and motor nerve conduction study. An electrophysiological examination can be reproduced and is also a non-invasive approach in the assessment of peripheral nerve function. Population-based and clinical studies have been conducted to validate the sensitivity of these methods. When the diagnosis was based on clinical electrophysiological examination, abnormalities were observed in all patients.

METHOD

In this research, using a review design, we reviewed the issue of clinical electrophysiological examination of diabetic peripheral neuropathy in articles from 2008 to 2017. For this purpose, PubMed, Scopus and Embase databases of journals were used for searching articles.

RESULTS/FINDINGS

The researchers indicated that diabetes (both types) is a very disturbing health issue in the modern world and should be given serious attention. Based on conducted studies, it was demonstrated that there are different procedures for prevention and treatment of diabetes-related health problems such as diabetic polyneuropathy (DPN). The first objective quantitative indication of the peripheral neuropathy is abnormality of sensory and motor nerve conduction tests. Electrophysiology is accurate, reliable and sensitive. It can be reproduced and also is a noninvasive approach in the assessment of peripheral nerve function.

CONCLUSION

The methodological review has found that the best method for quantitative indication of the peripheral neuropathy compared with all other methods is clinical electrophysiological examination. For best results, standard protocols such as temperature control and equipment calibration are recommended.

HuoXueJieDu Formula Alleviates Diabetic Retinopathy in Rats by Inhibiting SOCS3-STAT3 and TIMP1-A2M Pathways

HuoXueJieDu (HXJD) formula exerts protective effects against diabetic retinopathy (DR) in rats, but its underlying mechanism remains unknown. In the present study, the diabetic rats were established using streptozocin. The administration of HXJD was initiated at 20 weeks after diabetes induction and continued for 12 weeks. Whole genome expression profiles in rat retinas were examined using microarray technology. Differential gene expression and pathway enrichment analysis were conducted on the microarray data, with validation through real-time PCR and immunohistochemical staining. The results showed that 170 genes and several IPA canonical pathways related to inflammation, matrix metabolism, and phototransduction were regulated by HXJD. PCR validation of selected genes, including SOCS3, STAT3, TIMP1, and A2M, confirmed the gene expression changes influenced by HXJD. In addition, the immunohistochemical staining results suggested that critical members of the SOCS3-STAT3 pathway were also affected by HXJD. Taken together, these results indicated that SOCS3-STAT3 and TIMP1-A2M pathways might mediate the alleviation of HXJD activities in rats with diabetic retinopathy.