Metformin attenuates diabetic neuropathic pain via AMPK/NF-κB signaling pathway in dorsal root ganglion of diabetic rats.

Neuropathic pain is a common complication of diabetes mellitus with poorly relieved by conventional analgesics. Metformin, a first-line drug for type 2 diabetes, reduces blood glucose by activating adenosine monophosphate protein kinase (AMPK) signalling system. However, the effect of Metformin on diabetic neuropathic pain is still unknown. In the present study, we showed that Metformin was capable of attenuating diabetes induced mechanical allodynia, and the analgesia effect could be blocked by Compound C (an AMPK inhibitor). Importantly, Metformin enhanced the phosphorylation level of AMPK in L4-6 DRGs of diabetic rats but not affect the expression of total AMPK. Intrathecal injection of AICAR (an AMPK agonist) could activate AMPK and alleviate the mechanical allodynia of diabetic rats. Additionally, phosphorylated AMPK and NF-κB was co-localized in small and medium neurons of L4-6 DRGs. Interestingly, the regulation of NF-κB in diabetic rats was obviously reduced when AMPK was activated by AICAR. Notably, Metformin could decrease NF-κB expression in L4-6 DRGs of diabetic rats, but the decrease was blocked by Compound C. In conclusion, Metformin alleviates diabetic mechanical allodynia via activation of AMPK signaling pathway in L4-6 DRGs of diabetic rats, which might be mediated by the downregulation of NF-κB, and this providing certain basis for Metformin to become a potential drug in the clinical treatment of diabetic neuropathic pain.

Serum Fibroblast Growth Factor 19 and Total Bile Acid Concentrations Are Potential Biomarkers of Hepatocellular Carcinoma in Patients with Type 2 Diabetes Mellitus.

PURPOSE: Type 2 diabetes mellitus (T2DM) carries a high risk of hepatocellular carcinoma (HCC). Both serum fibroblast growth factor 19 (FGF19) and bile acid concentrations are associated with T2DM and HCC. We aimed at evaluating the relationships between FGF19 and bile acid concentrations and HCC in patients with T2DM. METHODS: Twenty-seven healthy volunteers (control group), 27 patients with T2DM (T2DM group), 16 patients with newly diagnosed HCC (HCC group), and 10 T2DM patients with newly diagnosed HCC (T2DM-HCC group) were studied at the Affiliated Hospital of Nantong University between June 2016 and June 2017. The serum concentrations of serum FGF19 and total bile acids (TBA) were measured in all the participants. Correlation analysis and multiple stepwise regression analysis of the FGF19 and TBA concentrations were performed in all the participants and in the four groups. RESULTS: The concentrations of FGF19 were 220.5 pg/ml, 185.1 pg/ml, 115.8 pg/ml, and 70.4 pg/ml in the HCC, T2DM-HCC, control, and T2DM groups, respectively (p < 0.001), and the TBA concentrations were 21.75 µmol/l, 14.25 µmol/l, 14.25 µmol/l, 14.25 µmol/l, 14.25 p < 0.001), and the TBA concentrations were 21.75 r = 0.777; p < 0.001), and the TBA concentrations were 21.75 r = 0.777; p < 0.001), and the TBA concentrations were 21.75 r = 0.777; p < 0.001), and the TBA concentrations were 21.75 r = 0.777; p < 0.001), and the TBA concentrations were 21.75 r = 0.777; p < 0.001), and the TBA concentrations were 21.75 . CONCLUSIONS: Simultaneous increase of serum FGF19 and TBA levels may be used as indicators of HCC screening at early stage in patients with T2DM.

Anti-atherosclerotic effect of hesperidin in LDLr-/- mice and its possible mechanism.

Hesperidin, a citrus bioflavonoid, exerts numerous pharmacological activities. However, its protective effect against atherosclerosis in vivo remains poorly understood. In the present study, we aimed to observe the effects of hesperidin on high fat diet (HFD)-induced atherosclerosis using LDL receptor deficient (LDLr-/-) mice. After 12 weeks of treatment, the animals were sacrificed. The blood samples were collected for further analysis. Mouse peritoneal macrophages were collected. Hepatic lipid content, quantification of atherosclerosis, assessment of oxidative stress and inflammation, gene expressions were performed on liver and aorta samples. The data showed that hesperidin ameliorated HFD-induced weight gain, improved insulin resistance and ameliorated hyperlipidemia. Hesperidin suppressed HFD-induced hepatic steatosis, atherosclerotic plaque area and macrophage foam cell formation. Further study showed that hesperidin down-regulated expressions of acetyl coenzyme A carboxylase alpha (ACCα) and fatty acid synthase (FAS) which are two key enzymes in fatty acid and triglyceride synthesis in liver; and upregulated expression of hepatic ATP-binding cassette transporters G8 (ABCG8), macrophage ATP-binding cassette transporters A1 (ABCA1) and G1 (ABCG1) which are transporters involved in the process of reverse cholesterol transport. Hesperidin also reduced oxidative stress by normalizing activities of antioxidant enzymes and inflammation in HFD-fed LDLr-/- mice. These findings suggest that hesperidin reduced atherosclerosis via its pleiotropic effects, including improvement of insulin resistance, amelioration of lipid profiles, inhibition of macrophage foam cell formation, anti-oxidative effect and anti-inflammatory action.