Targeted metabolomics reveals the aberrant energy status in diabetic peripheral neuropathy and the neuroprotective mechanism of traditional Chinese medicine JinMaiTong.

Diabetic peripheral neuropathy (DPN) is a common and devastating complication of diabetes, for which effective therapies are currently lacking. Disturbed energy status plays a crucial role in DPN pathogenesis. However, the integrated profile of energy metabolism, especially the central carbohydrate metabolism, remains unclear in DPN. Here, we developed a metabolomics approach by targeting 56 metabolites using high-performance ion chromatography-tandem mass spectrometry (HPIC-MS/MS) to illustrate the integrative characteristics of central carbohydrate metabolism in patients with DPN and streptozotocin-induced DPN rats. Furthermore, JinMaiTong (JMT), a traditional Chinese medicine (TCM) formula, was found to be effective for DPN, improving the peripheral neurological function and alleviating the neuropathology of DPN rats even after demyelination and axonal degeneration. JMT ameliorated DPN by regulating the aberrant energy balance and mitochondrial functions, including excessive glycolysis restoration, tricarboxylic acid cycle improvement, and increased adenosine triphosphate (ATP) generation. Bioenergetic profile was aberrant in cultured rat Schwann cells under high-glucose conditions, which was remarkably corrected by JMT treatment. In-vivo and in-vitro studies revealed that these effects of JMT were mainly attributed to the activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and downstream peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Our results expand the therapeutic framework for DPN and suggest the integrative modulation of energy metabolism using TCMs, such as JMT, as an effective strategy for its treatment.

The complete chloroplast genome sequence of Aspidopterys concava (Wall.) A. Juss. (Malpighiaceae).

Aspidopterys concava is related to a group of important medicinal plants in Malpighiaceae in southeast Asia. Here, we report the first chloroplast genome fully sequenced and annotated for Aspidopterys concava. The genome size was 160,441 bp and contained a large single-copy (LSC) region of 71,434 bp, a small single-copy (SSC) region of 53,544 bp, and a pair of inverted repeats (IRs) regions of 8943 bp. Total GC content was 37.9%. It contained 125 genes in total, comprising 82 protein-coding genes, 37 transfer RNA genes, and six ribosomal RNA genes. Phylogenetic analysis showed that A. concava was the most closely related to A. obcordata from the same genus.

Efficacy and Safety of Mulberry Twig Alkaloids Tablet for Treatment of Type 2 Diabetes: A Randomized, Double-Blind, Placebo-Controlled Multicenter Clinical Study.

OBJECTIVE: To assess the efficacy and safety of mulberry twig alkaloids (Sangzhi alkaloids, SZ-A) for treatment of type 2 diabetes in a randomized, double-blind, placebo-controlled multicenter clinical trial. METHODS: A total of 200 patients were randomized to receive SZ-A (n=100) or placebo (n=100) for 16 weeks. The data analysis system for electronic data capture clinical trial central randomization system was used for randomization and dispensing of drugs. The primary outcome was the change in glycosylated hemoglobin (HbA1c) level. The secondary outcome included the proportions of cases with HbA1c <7.0% and HbA1c <6.5%, fasting blood glucose (FBG), postprandial blood glucose (PBG), area under curve for the PBG (AUC0-2h), body weight, and body mass index (BMI). Adverse events (AEs), severe adverse events (SAEs), treatment-related adverse events (TAEs), gastrointestinal disorders (GDs), blood pressure, routine blood tests, and liver and kidney function were monitored. RESULTS: Compared with baseline, the change of HbA1c at week 16 was -0.80% (95% CI: -0.98% to -0.62%) and -0.09% (95% CI: -0.27% to 0.09%) in SZ-A group and placebo group, respectively. The proportion of patients with HbA1c <7% and <6.5% was higher in the SZ-A group than in the placebo group (46.8% vs. 21.6% and 29.9% vs. 10.8%). The observed values and changes in FBG, 1 h-PBG, 2 h-PBG, and AUC0-2h differed significantly between groups (P<0.001), but differences were not significant in body weight and BMI (P>0.05). The incidence rates of AEs, TAEs, and GDs differed significantly between groups (P=0.010, P=0.005, and P=0.006, respectively), whereas the incidence rates of SAEs showed no significant differences between groups (P=1.000). CONCLUSION: SZ-A are effective and safe for treatment of type 2 diabetes. The protocol was registered in http://www.chictr.org.cn/showproj.aspx?proj=60117 (ChiCTR2000038550).

Jinmaitong Alleviates Diabetic Neuropathic Pain Through Modulation of NLRP3 Inflammasome and Gasdermin D in Dorsal Root Ganglia of Diabetic Rats.

Jinmaitong (JMT) is a compound prescription of traditional Chinese medicine that has been used to treat diabetic neuropathic pain (DNP) for many years. Here, we investigated the effects of JMT on the activation of NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome and pyroptosis in Dorsal root ganglia (DRG) of diabetic rats. Streptozotocin (STZ)-induced diabetic rats were gavaged with JMT (0.88 g/kg/d) or alpha-lipoic acid (ALA, positive control, 0.48 mmol/kg/d) for 12 weeks. Distilled water was administered as a vehicle control to both diabetic and non-affected control rats. Blood glucose levels and body weights were measured. Behavioral changes were tested with mechanical withdrawal threshold (MWT) and tail-flick latency (TFL) tests. Morphological injury associated with DRG was observed with hematoxylin and eosin (H&E) and Nissl's staining. mRNA and protein levels of NLRP3 inflammasome components (NLRP3, ASC, caspase-1), downstream IL-1ß and gasdermin D (GSDMD) were evaluated by immunohistochemistry, quantitative real time-PCR and western blot. The results showed that JMT had no effect on blood glucose levels and body weights, but significantly improved MWT and TFL behavior in diabetic rats, and attenuated morphological damage in the DRG tissues. Importantly, JMT decreased the mRNA and protein levels of components of NLRP3 inflammasome, including NLRP3, ASC and caspase-1. JMT also down-regulated the expression of IL-1ß and GSDMD in the DRG of DNP rats. In addition, ALA treatment did not perform better than JMT. In conclusion, JMT effectively relieved DNP by decreasing NLRP3 inflammasome activation and pyroptosis, providing new evidence supporting JMT as an alternative treatment for DNP.

Jinmaitong ameliorates diabetes-induced peripheral neuropathy in rats through Wnt/ß-catenin signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Jinmaitong (JMT) is a prescription of Traditional Chinese Medicine, which is composed of ten herbal drugs and two animal drugs. It has long been used for the treatment of diabetic peripheral neuropathy (DPN). AIM OF STUDY: Wnt/ß-catenin pathway is considered as an essential and direct driver of myelinogenesis. This study aims to evaluate the protective effect of JMT against DPN dynamically during a 16-weeks' treatment, and to investigate the underlying mechanism in which the Wnt/ß-catenin pathway is involved. MATERIALS AND METHODS: Diabetic model was induced by single intraperitoneal injection of Streptozotocin (STZ) using male Sprague-Dawley rats. The model rats were divided into five groups and administrated with JMT at three doses (0.437, 0.875, and 1.75 g/kg per day), neurotropin (positive drug, 2.67 NU/kg per day), and placebo (deionized water), respectively, for continuous 8 weeks (n = 9-10), 12 weeks (n = 8-10), or 16 weeks (n = 7-9). Meanwhile, rats in control group were administrated with placebo (n = 10 for 8 weeks, n = 9 for 12 and 16 weeks, respectively). Blood glucose and body weight were monitored every four weeks. Mechanical allodynia was assessed using mechanical withdrawal threshold (MWT) test. The morphological change of sciatic nerves were observed by transmission electron microscope (TEM) and hematoxylin and eosin (HE) stain. The mRNA and protein levels of targeted genes were evaluated by quantitative real time-PCR and western bolt, respectively. Myelin protein zero (MPZ) and mediators involved in Wnt/ß-catenin pathway, such as ß-catenin, glycogen synthase kinase 3ß (GSK-3ß), and WNT inhibitory factor-1 (WIF-1), were compared among different groups after treatment of 8, 12, and 16 weeks, respectively. RESULTS: The mechanical allodynia and peripheral nerve morphology were degenerated in DPN rats over time, and notably improved after JMT-treatment of 12 and 16 weeks. The decreased MPZ level in DPN rats were also significantly amended by JMT. More importantly, we found that the suppressed Wnt/ß-catenin pathway in sciatic nerves of DPN rats was overtly up-regulated by JMT in a time-dependent manner. Among the three doses, JMT at the middle dose showed the best effect. CONCLUSIONS: JMT effectively ameliorated diabetic-induced peripheral neuropathy, which was mediated by the activation of Wnt/ß-catenin signaling pathway. This study provided new perspective to understand the neuroprotective mechanism of JMT.

Jinmaitong ameliorates diabetic peripheral neuropathy in streptozotocin-induced diabetic rats by modulating gut microbiota and neuregulin 1.

Jinmaitong (JMT), a compound prescription of traditional Chinese medicine, has long been used as a therapy for diabetic peripheral neuropathy (DPN). However, the neuroprotective mechanisms of JMT and its effect on gut microbiota remained unknown. Here, we examined the effects of JMT on behavior, pathomorphology and gut microbiota in streptozotocin (STZ)-induced DPN rats. Compared to distilled water administration, JMT reversed decreases in mechanical withdraw threshold and intraepidermal nerve fiber density, improved neurological morphology of sciatic nerves, increased serum neuregulin 1 (NRG1) level and contactin-associated protein (Caspr)-positive paranodes, and decreased amyloid precursor protein (APP) accumulation in DPN rats. More importantly, JMT enriched nine species of the gut microbiota of DPN rats, helping to prevent dysbiosis. Among these species, p_Actinobacteria, p_Proteobacteria and c_Actinobacteria were negatively correlated with DPN phenotypes and positively correlated with serum NRG1 level. These results indicate that JMT may exert a neuroprotective effect by modulating phenotype-associated gut microbiota and increasing serum NRG1 level in STZ-induced DPN rats. JMT may therefore be an effective complementary and alternative anti-DPN therapy.

Combination of Quercetin, Hirudin and Cinnamaldehyde Promotes Schwann Cell Differentiation and Myelination against High Glucose by Inhibiting ERK Signaling Pathway.

OBJECTIVE: To investigate the therapeutic and synergistic effects of QHC (combination of quercetin (Q), hirudin (H) and cinnamaldehyd (C)) on Schwann cell differentiation and myelination against high glucose (HG) induced injury. METHODS: Primary-culture Schwann cells exposed to HG (50 mmol/L) for 72 h and Schwann cell-dorsal root ganglion (DRG) neuron cocultures exposed to HG (50 mmol/L) for 7 days were employed as in vitro model of diabetic neuropathy. The cells were randomly divided into 10 groups: control (CON, 25 mmol/L glucose), HG (50 mmol/L glucose), HG plus 10 µmol/L quercetin (Q), HG plus 0.04 IU/mL hirudin (H), HG plus 100 nmol/L cinnamaldehyd (C), HG plus 10 µmol/L quercetin and 0.04 IU/mL hirudin (QH), HG plus 10 µmol/L quercetin and 50 nmol/L cinnamaldehyd (QC), HG plus 0.04 IU/mL hirudin and 50 nmol/L cinnamaldehyd (HC), HG plus 10 µmol/L quercetin, 0.04 IU/mL hirudin and 50 nmol/L cinnamaldehyd (QHC) or 10 µmol/L U0126. Cell differentiation was evaluated by periaxin immunofluorescence staining. The protein expression levels of myelin protein zero (P0), myelin basic protein (MBP), myelin-associated glycoprotein (MAG), extracellular signal-regulated kinase (ERK), p-ERK, p-c-Jun, c-Jun, notch intracellular domain (NICD) and the mRNA expression levels of P0, MBP, MAG, Krox-20, Notch1 and Jagged1 were detected by Western blotting and real-time quantitative PCR analysis. The secretion of ciliary neurotrophic factor (CNTF) was determined by enzyme-linked immunosorbent assay (ELISA). The number and length of the myelin segments were evaluated by MBP immunofluorescence staining. The expression and the location of p-ERK in cocultures were detected by MAG and p-ERK immunofluorescence double staining. RESULTS: Co-treatment with Q, C, H and their combination promoted Schwann cell differentiation, increased CNTF secretion, up-regulated the protein and mRNA expressions of myelin, and increased the number and length of the myelin segments (P<0.01 or P<0.05). In particular, the combination therapy of Q, H and C was superior to the respective monotherapy (P<0.01). Combination therapy of QHC exhibited higher inhibitory activities for ERK signaling related molecules than each monomer or the combination of the two monomers (P<0.01). CONCLUSION: QHC combination yielded synergy in promoting Schwann cell differentiation and myelination and the protective effect may involve in the inhibition of ERK signaling pathway, providing scientific evidence for better understanding of combination of Q, H and C in clinical applications.

A Metabolic Insight Into the Neuroprotective Effect of Jin-Mai-Tong (JMT) Decoction on Diabetic Rats With Peripheral Neuropathy Using Untargeted Metabolomics Strategy.

Jin-Mai-Tong (JMT) decoction is a traditional Chinese compound prescription for treating diabetic peripheral neuropathy (DPN). The aim of this study is to investigate the neuroprotective effect of JMT decoction on diabetic rats with peripheral neuropathy and to elucidate the potential mechanism based on a metabolomics approach. Sprague-Dawley (SD) rats were randomly divided into four groups: control group, Streptozotocin (STZ) induced model group, JMT low dose (JMT-L) treated group and JMT high dose (JMT-H) treated group. After 12 weeks of treatment, behavioral changes, small fiber loss, and histopathological damages of sciatic nerves were estimated. Serum samples were collected for untargeted metabolomics analysis based on UPLC/QTOF-MS and multivariate statistics. As a result, JMT treatment at two dosages (13.9 and 27.8 g/kg⋅d) evidently improved the mechanical pain threshold (P < 0.05), increased the intraepidermal nerve fiber density (IENFD) and subepidermal nerve fiber density (SNFD) (P < 0.05), and renovated the demyelination and axonal atrophy of sciatic nerves on DPN rats. Furthermore, metabolomics study revealed that the serum metabolic profiles altered significantly among the control group and the STZ-induced model group. A total of 21 metabolites were identified as potential biomarkers related to the therapeutic effect of JMT decoction. Among them, 16 biomarkers were found in both JMT-H and JMT-L treated groups, while the five others were specific to JMT-H group. These metabolites mainly involved in lipid metabolism, tricarboxylic acid (TCA) cycle, amino acid metabolism, and so on. Besides, correlation analysis indicated that both mechanical pain threshold and distal nerve fiber density were negatively correlated with the serum levels of metabolites from lipid metabolism and TCA cycle. In conclusion, the results demonstrated that JMT decoction has an obvious protective effect against DPN, which could be mediated via ameliorating the metabolic disorders in diabetic rats with peripheral neuropathy.

Effects of Hirudin on High Glucose-Induced Oxidative Stress and Inflammatory Pathway in Rat Dorsal Root Ganglion Neurons.

OBJECTIVE: To investigate protective effects of hirudin on oxidative stress and apoptosis of spinal dorsal root ganglion cells in high-glucose rats at the cellular and molecular level. METHODS: Dorsal root ganglion neurons (DRGn) were harvested from embryonic day in 15 SD rats, purified and identificated after primary culture. They were divided into the normal control group, high-glucose (HG) group, positive control (alpha-lipoic acid, ALA) group, low-dose hirudin group (H1), medium-dose hirudin group (H2) and high-dose hirudin group (H3). The control group was cultured by neuron specific culture medium, while the HG group was cultured by neuron specific culture medium and 20 mmol/L glucose (HG medium). The hirudin groups were cultured by HG medium+0.25 IU/mL hirudin (H1), HG medium+0.5 IU/mL hirudin (H2) and HG medium+1 IU/mL hirudin (H3). The ALA group was cultured by HG medium+100 µ mol/L ALA. 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenylt etrazolium bromide (MTT) assay was used to explore the optimum concentration and intervention time. Flow cytometry assay was used to detect the level of reactive oxygen series (ROS). Western blot and quantificational realtime polymerase chain reaction (qRT-PCR) were used to detect the expression of protein and mRNA of nuclear factor erythroid 2-related factor 2 (Nrf-2), hemeoxygence-1 (HO-1), nuclear factor-κ B (NF-κ B) and Caspase-3. TUNEL assay was used to test the apoptosis rate of different groups. RESULTS: After 24 h of culture, the cell activity of hirudin and ALA groups were higher than that of HG group, and there was a statistical difference between the H1 group and HG group (P<0.05). In hirudin groups, the apoptosis rate of cells, the expression of activated Caspase-3 protein and Caspase-3 mRNA were lower than those of HG group (P<0.01), higher than those of ALA group (P<0.01 or P<0.05). The ROS level of hirudin groups was higher than that of ALA group (P<0.01), lower than that of HG group (P<0.01 or P<0.05). The expression of NF-κ B (P65) protein in H3 group were lower than those of HG group (P<0.05). The expression of Nrf-2 protein in hirudin groups was higher than that of HG group (P<0.01), lower than that of ALA group (P<0.01 or P<0.05). The expression of HO-1 protein in hirudin groups was lower than that of ALA group (P<0.01 or P<0.05), higher than that of HG group (P<0.01 or P<0.05). CONCLUSIONS: The activity of DRGn cells can be promoted by hirudin under HG conditions. The effects of hirudin on the inhibition of HG on DRGn cells damage mainly include scavenging ROS, up-regulating Nrf-2/HO-1 pathway, inhibiting activation of NF-κ B pathway, down-regulating the expression of and Caspase-3 and reducing DRGn cell apoptosis.

Humanistic Spirit Contained in Traditional Chinese Medicine should Be Valued.

Medicine is a science studying human's health and diseases as well as the regularity between them. Its research subject is human, who possess natural attribute, psychological attribute and social attribute. Therefore, medicine is bound to possess humanistic attribute. Rooted in Chinese traditional culture, Traditional Chinese Medicine contains abundant humanistic thoughts, for instance, pursuing the unity of human and nature, advocating the vital importance of life, sticking to the virtue of "medicine being humane art", abiding by the principle of "Benevolence prior to interest", complying with the medical rule of "Respecting peers". These are the very concrete reflections of medical humanistic spirit. In this article we aim to explore the humanistic thoughts contained in Traditional Chinese Medicine, and try to inherit and carry forward the spirit to better relieve the tensions between doctors and patients and improve the quality of medical services.

Effects of Mitochondrial Dysfunction via AMPK/PGC-1 α Signal Pathway on Pathogenic Mechanism of Diabetic Peripheral Neuropathy and the Protective Effects of Chinese Medicine.

Diabetic peripheral neuropathy (DPN) is a progressive neurodegenerative disease of peripheral nervous system with high energy requirement. The adenosine monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor- γ coactivator 1 α (PGC-1 α) axis plays a key role in regulating mitochondrial energy metabolism. Increasing preclinical evidences have shown that inhibition of AMPK/PGC-1 α pathway leading to mitochondrial dysfunction in neurons or Schwann cells contributes to neuron apoptosis, distal axonopathy and nerve demyelination in DPN. Some Chinese medicine formulae or extracts from herbs may have potential neuroprotective effects on DPN via activating AMPK/PGC-1 α pathway and improving mitochondrial function.

Strategies and Research Progress of Chinese Medicine in Prevention and Treatment of Diabetic Peripheral Neuropathy.

Diabetic peripheral neuropathy (DPN) seriously affects the quality of life in patients with type 2 diabetes mellitus. This paper reviews the role of Chinese medicine in the main treatment goal of DPN, including protecting pancreatic ß-cells, in the use of antioxidation therapy to delay disease progression, and in the endpoint of neural repair and regeneration. We propose that protecting the body from injury caused by high glucose and oxidative stress, and promoting repair and regeneration of nerves should be the research direction for the prevention and treatment of DPN.

Combination of quercetin, cinnamaldehyde and hirudin protects rat dorsal root ganglion neurons against high glucose-induced injury through Nrf-2/HO-1 activation and NF-κB inhibition.

OBJECTIVE: To examine the effects of the combination of quercetin (Q), cinnamaldehyde (C) and hirudin (H), a Chinese medicine formula on high glucose (HG)-induced apoptosis of cultured dorsal root ganglion (DRG) neurons. METHODS: DRG neurons exposed to HG (45 mmol/L) for 24 h were employed as an in vitro model of diabetic neuropathy. Cell viability, reactive oxygen species (ROS) level and apoptosis were determined. The expression of nuclear factor of Kappa B (NF-κB), inhibitory kappa Bα(IκBα), phosphorylated IκBα and Nf-E2 related factor 2 (Nrf2) were examined using reverse transcription-polymerase chain reaction (RT-PCR) and Western blot assay. The expression of hemeoxygenase-1 (HO-1), interleukin-6 (IL-6), tumor necrosis factor (TNF-α) and caspase-3 were also examined by RT-PCR and Western blot assay. RESULTS: HG treatment markedly increased DRG neuron apoptosis via increasing intracellular ROS level and activating the NF-κB signaling pathway (P<0.05). Co-treatment with Q, C, H and their combination decreased HG-induced caspase-3 activation and apoptosis (P<0.05 or P<0.01). The expressions of NF-κB, IL-6 and TNF-α were down-regulated, and Nrf2/HO-1 expression was up-regulated (P<0.05 or P<0.01). QCH has better effect in scavenging ROS, activating Nrf-2/HO-1, and down-regulating the NF-κB pathway than other treatment group. CONCLUSIONS: DRG neurons' apoptosis was increased in diabetic conditions, which was reduced by QCH formula treatment. The possible reason could be activating Nrf-2/HO-1 pathway, scavenging ROS, and inhibition of NF-κB activation. The effect of QCH combination was better than each monomer or the combination of the two monomers.

New developments in the pharmacodynamics and pharmacokinetics of combination of Chinese medicine and Western medicine.

It is very common to use Chinese medicine (CM) combined with Western medicine (WM) in clinical practice. The appropriate combination of CM with WM can reduce toxicity and enhance effects in order to make the best use of advantages and bypass the disadvantages. However, an inappropriate combination can not only affect the curative effect but even cause death. Therefore, strengthening the complementary advantages of the CM and WM to improve the therapeutic efficacy and reduce side effects has become an important research topic of clinical medicine and pharmacy. Many researchers try to clarify the effects of combining CM with WM on therapeutic efficacy and absorption, distribution, metabolism and excretion by pharmacodynamics and pharmacokinetics studies, providing evidence for clinical application. This review focuses on the new developments in the pharmacodynamics and pharmacokinetics of the combination of CM with WM in order to give references for clinical treatment.

Effects of Chinese Medicinal Compound Jinmaitong on the Expression of Nitrotyrosine andNerve Growth Factor in the Dorsal Root Ganglia of Diabetic Rats.

Objective To study the effects of Chinese medicinal compound Jinmaitong(JMT) on the expressions of nitrotyrosine (NT) and nerve growth factor (NGF) in dorsal root ganglia of diabetic rats. Methods Experimental rat diabetic models were established by the intraperitoneal injection of streptozotocin. Rat models were then randomly divided into four groups including normal control group (Con group),diabetes mellitus group (DM group),Jinmaitong group(JMT group)(treated with JMT similar to the fifteen-fold dose of adult recommended dosage),and taurine group(Tau group)(treated with Taurine similar to the fifteen-fold dose of adult recommended dosage),with 10 rats in each group. The Con and DM groups were treated with distilled water at a daily dose of 1 ml/100 g. All rats were given intragastric administration for 16 weeks and then killed. Body weight and blood glucose were detected before and at the 4th,8th,12th,and 16th week after treatment. The pain threshold to mechanical stimulation with von Frey filament were carried out before death. The expressions of NT and NGF in dorsal root ganglion were detected by immunohistochemistry and Western blot analysis,respectively. Results Immunohistochemistry showed that the average optical density (AOD) of NT expression in DM group were significantly higher than those in control group (P=0.000),and the AOD of NGF was significantly lower than the control group (P=0.006).The AOD of NT(P=0.000,P=0.000) in both treatment groups decreased significantly and the AOD of NGF(P=0.000, P=0.004)significantly increased compared with DM group. The AOD of NT in JMT group was significantly lower than Tau group (P=0.004). Western blot analysis showed that the protein level of NT in DM group was significantly higher than that in control group (P=0.000),and the protein level of NGF was significantly lower than that in control group (P=0.000). Compared with the DM group,the protein level of NT in both treatment groups significantly decreased (P=0.001,P=0.000),and the protein level of NGF increased significantly (P=0.000,P=0.001). Conclusion Traditional Chinese medicine JMT can obviously up-regulate the expressions of NGF and reduce the NT levels in dorsal root ganglia of diabetic rats.

Jinmaitong alleviates the diabetic peripheral neuropathy by inducing autophagy.

OBJECTIVE: To observe the deregulation of autophagy in diabetic peripheral neuropathy (DPN) and investigate whether Jinmaitong ( JMT) alleviates DPN by inducing autophagy. METHODS: DPN models were established by streptozotocin-induced diabetic rats and Schwann cells (SCs) cultured in high glucose medium. The pathological morphology was observed by the improved Bielschowsky's nerve fiber axonal staining and the Luxol fast blue-neutral red myelin staining. The ultrastructure was observed by the transmission electron microscopy. Beclin1 level was detected by immunohistochemistry and Western blot. The proliferation of cultured SCs was detected by methylthiazolyldiphenyl-tetrazolium bromide. RESULTS: Diabetic peripheral nerve tissues demonstrated pathological morphology and reduced autophagic structure, accompanied with down-regulation of Beclin1. JMT apparently alleviated the pathological morphology change and increased the autophagy [in vivo, Beclin1 integral optical density (IOD) value of the control group 86.6±17.7, DM 43.9±8.8, JMT 73.3 ±17.8, P<0.01 or P<0.05, in vitro Beclin1 IOD value of the glucose group 0.47±0.25 vs the control group 0.88±0.29, P<0.05]. Consequently, inhibition of autophagy by 3-methyladenine resulted in a time- and concentration-dependent decrease of the proliferation of SCs (P<0.05, P<0.01). CONCLUSIONS: Down-regulation of autophagy in SCs might contribute to the pathogenesis of DPN. JMT alleviates diabetic peripheral nerve injury at least in part by inducing autophagy.

Anti-oxidative and anti-inflammatory effects of cinnamaldehyde on protecting high glucose-induced damage in cultured dorsal root ganglion neurons of rats.

OBJECTIVE: To examine the mechanism underlying the beneficial role of cinnamaldehyde on oxidative damage and apoptosis in high glucose (HG)-induced dorsal root ganglion (DRG) neurons in vitro. METHODS: HG-treated DRG neurons were developed as an in vitro model of diabetic neuropathy. The neurons were randomly divided into five groups: the control group, the HG group and the HG groups treated with 25, 50 and 100 nmol/L cinnamaldehyde, respectively. Cell viability was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and apoptosis rate was evaluated by the in situ TdT-mediated dUTP nick end labeling (TUNEL) assay. The intracellular level of reactive oxygen species (ROS) was measured with flow cytometry. Expression of nuclear factor-kappa B (NF-κB), inhibitor of κB (IκB), phosphorylated IκB (p-IκB), tumor necrosis factor (TNF)-α, interleukin-6 (IL-6) and caspase-3 were determined by western blotting and real-time quantitative reverse transcription polymerase chain reaction (RT-PCR). Expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase-1 (HO-1) were also measured by western blotting. RESULTS: Cinnamaldehyde reduced HG-induced loss of viability, apoptosis and intracellular generation of ROS in the DRG neurons via inhibiting NF-κB activity. The western blot assay results showed that the HG-induced elevated expressions of NF-κB, IκB and p-IκB were remarkably reduced by cinnamaldehyde treatment in a dose-dependent manner (P <0.01). The HG-induced over-expression of NF-κB p65 mRNA was remarkably attenuated after cinnamaldehyde treatment in a dose-dependent manner (P <0.01). However, the expressions of Nrf2 and HO-1 were not upregulated. Treatment with cinnamaldehyde not only attenuated caspase-3 activation and the caspase cleavage cascade in DRG neurons, but also lowered the elevated IL-6, TNF-α, cyclo-oxygenase and inducible nitric oxide synthase levels, indicating a reduction in inflammatory damage. CONCLUSIONS: Cinnamaldehyde protected DRG neurons from the deleterious effects of HG through inactivation of NF-κB pathway but not through activation of Nrf2/HO-1. And thus cinnamaldehyde may have potential application as a treatment for DPN.

Jinmaitong decreases sciatic nerve DNA oxidative damage and apoptosis in a streptozotocin-induced diabetic rat model.

Diabetic peripheral neuropathy (DPN) is a common chronic complication of diabetes. Jinmaitong (JMT), a Traditional Chinese Medicine, improves certain symptoms of DPN, such as limb pain and numbness. The aim of the present study was to investigate the effects of JMT on DNA oxidative damage and apoptosis in the sciatic nerve of diabetic rats. The rats were divided into a normal and a diabetic group. Diabetes was induced using streptozotocin (60 mg/kg). The diabetic model (DM) rats received vitamin C (0.05 g/kg/day) or JMT [low-dosage (L), 0.44 g/kg/day; medium-dosage (M), 0.88 g/kg/day or high-dosage (H), 1.75 g/kg/day]. After 16 weeks, the mechanical pain threshold of the rats was evaluated. The expression of 8-hydroxy-deoxyguanosine (8-OHdG), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase p22phox, B-cell lymphoma 2 (Bcl-2), caspase 3 and cleaved-poly(ADP-ribose) polymerase 1 (PARP-1) in the sciatic nerve tissues was measured using the reverse transcription-quantitative polymerase chain reaction, immunohistochemistry and western blotting. JMT had no effect on body weight and fasting blood glucose levels. Following treatment, the rats in the JMT groups had an improved pain threshold compared with the DM controls (JMT-L, 52.9±6.5 g; JMT-M, 74.7±9.3 g; and JMT-H, 61.7±2.0 g vs. DM control, 35.32±12.06 g; all P<0.01), while the threshold in the JMT-M rats was similar to that of normal controls (P>0.05). 8-OHdG and NADPH oxidase p22phox expression was significantly decreased in the three JMT groups compared with that in the DM controls (all P<0.05). Following JMT treatment, Bcl-2 levels were increased, while caspase 3 and cleaved-PARP-1 levels were decreased compared with those in the DM controls (all P<0.01). In conclusion, JMT may reduce DNA oxidative damage to the sciatic nerve in diabetic rats, as well as regulate genes involved in peripheral neuronal cell apoptosis, suggesting that JMT could be used to prevent or treat DPN in diabetic patients.

[Progress in study of antioxidant effects of Coptis chinensis and its major contributions to diabetes treatment/therapy].

Coptis chinensis, a traditional Chinese medicine, has been found to have multiple pharmacological effects recently. Some research showed that C. chinensis has antioxidant effects, including scavenging oxygen free radicals, alleviating lipid peroxidation, enhancing activity of antioxidant enzymes, et al. C. chinensis may inhibit several classical pathological pathways in diabetes. C. chinensis is a potential medicine to prevent and treat diabetes mellitus and its complications. This review focuses on the recent research progress in the study of antioxidant effects of C. chinensis and its major contributions to diabetes treatment/therapy.

The Effects of Chinese Medicine on Activation of Wnt/ß-Catenin Signal Pathway under High Glucose Condition.

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycemia and a series of complications. The Wnt/ß-catenin signaling pathway is a complex protein interaction network, which is also a key regulator of cell proliferation and differentiation. Many scholars have found that high glucose can activate the Wnt signaling pathway. However, the effects of activation of this pathway in the presence of high glucose levels during the progression of diabetes still remained unclear. Here, we provide a review of the study on the effects of high glucose state on the Wnt/ß-catenin signal pathway and the influence of Chinese medicine on it.