[Tetrahydropalmatine alleviated diabetic neuropathic pain by inhibiting activation of microglia via p38 MAPK signaling pathway].

Neuropathic pain is one of the common complications of diabetes. Tetrahydropalmatine(THP) is a main active component of Corydalis Rhizoma with excellent anti-inflammatory and pain-alleviating properties. This study aims to investigate the therapeutic effect of THP on diabetic neuropathic pain(DNP) and the underlying mechanism. High-fat and high-sugar diet(4 weeks) and streptozotocin(STZ, 35 mg·kg~(-1), single intraperitoneal injection) were employed to induce type-2 DNP in rats. Moreover, lipopolysaccharide(LPS) was used to induce the activation of BV2 microglia in vitro to establish an inflammatory cellular model. Fasting blood glucose(FBG) was measured by a blood glucose meter. Mechanical withdrawal threshold(MWT) was assessed with von Frey filaments, and thermal withdrawal latency(TWL) with hot plate apparatus. The protein expression levels of OX42, inducible nitric oxide synthase(iNOS), CD206, p38, and p-p38 were determined by Western blot, the fluorescence expression levels of OX42 and p-p38 in the dorsal horn of the rat spinal cord by immunofluorescence, the mRNA content of p38 and OX42 in rat spinal cord tissue by qRT-PCR, and levels of nitric oxide(NO), interleukin-1ß(IL-1ß), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), interleukin-10(IL-10), and serum fasting insulin(FINS) by enzyme-linked immunosorbent assay(ELISA). RESULTS:: showed that the mo-del group demonstrated significant decrease in MWT and TWL, with pain symptoms. THP significantly improved the MWT and TWL of DNP rats, inhibited the activation of microglia and p38 MAPK signaling pathway in rat spinal cord, and ameliorated its inflammatory response. Meanwhile, THP promoted the change of LPS-induced BV2 microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, suppressed the activation of the p38 MAPK signaling pathway, decreased the expression levels of inflammatory factors NO, IL-1ß, IL-6, and TNF-α, and increased the expression level of anti-inflammatory factor IL-10. The findings suggested that THP can significantly ameliorate the pain symptoms of DNP rats possibly by inhibiting the inflammatory response caused by M1 polarization of microglia via the p38 MAPK pathway.

Acupuncture attenuates the development of diabetic peripheral neuralgia by regulating P2X4 expression and inflammation in rat spinal microglia.

Diabetic peripheral neuropathy (DPN) is a chronic microvascular complication of diabetes. The purpose of this study is to find the underlying mechanism for the effects of acupuncture in DPN rats. Rats were rendered diabetic with a single injection of 35 mg/kg streptozotocin (STZ). These STZ-diabetic rats were treated with acupuncture for 20 min once daily. The therapeutic efficacy of acupuncture was assessed using mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) evaluations. After 14 days treatment, acupuncture markedly reduced the pathological injury in STZ-diabetic rats. Moreover, it significantly down-regulated P2X4 and OX42 expression along with the reduced levels of inflammatory factors (CXCR3, TNF-α, IL-1ß, IL-6), GSP and lipid metabolisms in the spinal cord of the DPN rats. Acupuncture could relieve DPN in rats by regulating P2X4 expression and inflammation in spinal microglia.

Effects of traditional Chinese exercises on blood glucose and hemoglobin A1c levels in patients with prediabetes: A systematic review and meta-analysis.

BACKGROUND: Traditional Chinese exercises (TCEs) have a positive effect on glycemic control and hemoglobin A1c (HbA1c), but there is no consensus on the benefits of TCEs for patients with prediabetes. OBJECTIVE: The objective of this study was to systematically investigate the effects of TCEs on blood glucose control in patients with prediabetes. SEARCH STRATEGY: Comprehensive retrieval of randomized controlled trials (RCTs) was carried out using PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals, Wanfang Data Knowledge Service Platform, China Biology Medicine disc, Google Scholar and Baidu academic databases. The retrieval window ranged from the establishment of the database to December 2018, and references related to the included trials were searched without language restrictions. INCLUSION CRITERIA: The study included RCTs with a clinical diagnosis of prediabetes that was also treated with TCEs. DATA EXTRACTION AND ANALYSIS: Literature screening, data extraction and literature quality assessment were performed independently by two researchers. In the case of disagreement, a third party was invited to negotiate and make a decision. Standardized mean difference (SMD) was used to estimate the therapeutic effect. Meta-analysis was performed using Review Manager 5.3.5 and Stata 15.0. Heterogeneity was assessed using Q test and I2, and the source of heterogeneity was determined using Galbraith diagram and sensitivity analysis. A Q test resulting in P < 0.1 and I2 > 50% indicated significant difference and random effect model analysis was performed. Otherwise, a fixed effect model was applied. Begg's and Egger's tests were used to assess publication bias. RESULTS: Nine RCTs involving 485 participants were included in this study. The results showed that TCEs could reduce fasting blood glucose (FBG), 2 h blood glucose (2hPBG) and HbA1c in patients with prediabetes. The treatment subgroup showed that an intervention of 6 months had better results, while the Gongfa subgroup showed that the TCE Baduanjin yielded better results. (1) FBG: SMD = -0.73, 95% confidence interval (CI) [-0.97, -0.50], P < 0.00001; Baduanjin: SMD = -0.83, 95% CI [-1.13, -0.53], P < 0.00001; 6 month treatment: SMD = -0.73, 95% CI [-1.20, -0.26], P = 0.002. (2) 2hPBG: SMD = -0.75, 95% CI [-0.94, -0.57], P < 0.00001; Baduanjin: SMD = -0.62, 95% CI [-0.91, -0.32], P < 0.00001; 6 month treatment: SMD = -0.91, 95% CI [-1.39, -0.44], P = 0.0002. (3) HbA1c: SMD = -0.56, 95% CI [-0.89, -0.23], P = 0.00008; Baduanjin: SMD = -0.46, 95% CI [-0.83, -0.08], P = 0.02; 6 month treatment: SMD = -0.77, 95% CI [-1.24, -0.29], P = 0.002. CONCLUSION: TCEs had positive effects in improving blood glucose levels in patients with prediabetes. Hence, TCEs may be of potential therapeutic value for patients with prediabetes, as an adjuvant therapy along with other treatments. Although the evidence suggests that the intervention is effective for 6 months, the mechanism of TCEs on glycemic control, the minimum exercise dose and their safety remain to be further studied.

Understanding the Signaling Pathways Related to the Mechanism and Treatment of Diabetic Peripheral Neuropathy.

Worldwide, the most prevalent metabolic disorder is diabetes mellitus (DM), an important condition that has been widely studied. Diabetic peripheral neuropathy (DPN), a complication that can occur with DM, is associated with pain and can result in foot ulcers and even amputation. DPN treatments are limited and mainly focus on pain management. There is a clear need to develop treatments for DPN at all stages. To make this progress, it is necessary to understand the molecular signaling pathways related to DPN. For this review, we aimed to concentrate on the main signaling cascades that contribute to DPN. In addition, we provide information with regard to treatments that are being explored.