Protective effects of curcumin on desipramine-induced islet ß-cell damage via AKAP150/PKA/PP2B complex.

Tricyclic antidepressants (TCAs) are widely used to treat depression and anxiety-related mood disorders. But evidence shows that TCAs elevate blood glucose levels and inhibit insulin secretion, suggesting that TCAs are a risk factor, particularly for individuals with diabetes. Curcumin is a bioactive molecule from the rhizome of the Curcuma longa plant, which has shown both antidepressant and anti-diabetic activities. In the present study, we investigated the protective effect of curcumin against desipramine-induced apoptosis in ß cells and the underlying molecular mechanisms. In the mouse forced swimming test (FST), we found that lower doses of desipramine (5 and 10 mg/kg) or curcumin (2.5 mg/kg) alone did not affect the immobility time, whereas combined treatment with curcumin (2.5 mg/kg) and desipramine (5, 10 mg/kg) significantly decreased the immobility time. Furthermore, desipramine dose-dependently inhibited insulin secretion and elevated blood glucose levels, whereas the combined treatment normalized insulin secretion and blood glucose levels. In RIN-m5F pancreatic ß-cells, desipramine (10 µM) significantly reduced the cell viability, whereas desipramine combined with curcumin dose-dependently prevented the desipramine-induced impairment in glucose-induced insulin release, most effectively with curcumin (1 and 10 µM). We demonstrated that desipramine treatment promoted the cleavage and activation of Caspase 3 in RIN-m5F cells. Curcumin treatment inhibited desipramine-induced apoptosis, increased mitochondrial membrane potential and Bcl-2/Bax ratio. Desipramine increased the generation of reactive oxygen species, which was reversed by curcumin treatment. Curcumin also inhibited the translocation of forkhead box protein O1 (FOXO1) from the cytoplasm to the nucleus and suppressed the binding of A-kinase anchor protein 150 (AKAP150) to protein phosphatase 2B (PP2B, known as calcineurin) that was induced by desipramine. These results suggest that curcumin protects RIN-m5F pancreatic ß-cells against desipramine-induced apoptosis by inhibiting the phosphoinositide 3-kinase/AKT/FOXO1 pathway and the AKAP150/PKA/PP2B interaction. This study suggests that curcumin may have therapeutic potential as an adjunct to antidepressant treatment.

A Review Concerning the Polysaccharides Found in Edible and Medicinal Plants in Xinjiang.

Approximately 110 types of medicinal materials are listed in the Chinese Pharmacopoeia, both for medicinal purposes and for use as food. There are several domestic scholars who have carried out research on edible plant medicine in China and the results are satisfactory. Though these related articles have appeared in domestic magazines and journals, many of them are yet to be translated into English. Most of the research stays in the extraction and quantitative testing stage, and there are a few medicinal and edible plants that are still under in-depth study. A majority of these edible and herbal plants are also highly enriched in polysaccharides, and this has an effect on immune systems for the prevention of cancer, inflammation, and infection. Comparing the polysaccharide composition of medicinal and edible plants, the monosaccharide and polysaccharide species were identified. It is found that different polysaccharides of different sizes have different pharmacological properties, with some polysaccharides containing special monosaccharides. The pharmacological properties of polysaccharides can be summarized as immunomodulatory, antitumor, anti-inflammatory, antihypertensive and anti-hyperlipemic, antioxidant, and antimicrobial properties. There have been no poisonous effects found in studies of plant polysaccharides, probably because the substances have a long history of use and are safe. In this paper, the application potential of polysaccharides in medicinal and edible plants in Xinjiang was reviewed, and the research progress in the extraction, separation, identification, and pharmacology of these plant polysaccharides was reviewed. At present, the research progress of plant polysaccharides in medicines and food in Xinjiang has not been reported. This paper will provide a data summary for the development and utilization of medical and food plant resources in Xinjiang.

Curcumin attenuates palmitate-induced apoptosis in MIN6 pancreatic ß-cells through PI3K/Akt/FoxO1 and mitochondrial survival pathways.

Lipotoxicity plays a vital role in development and progression of type 2 diabetes. Prolonged elevation of free fatty acids especially the palmitate leads to pancreatic ß-cell dysfunction and apoptosis. Curcumin (diferuloylmethane), a polyphenol from the curry spice turmeric, is considered to be a broadly cytoprotective agent. The present study was designed to determine the protective effect of curcumin on palmitate-induced apoptosis in ß-cells and investigate underlying mechanisms. Our results showed that curcumin improved cell viability and enhanced glucose-induced insulin secretory function in MIN6 pancreatic ß-cells. Palmitate incubation evoked chromatin condensation, DNA nick end labeling and activation of caspase-3 and -9. Curcumin treatment inhibited palmitate-induced apoptosis, relieved mitochondrial depolarization and up-regulated Bcl-2/Bax ratio. Palmitate induced the generation of reactive oxygen species and inhibited activities of antioxidant enzymes, which could be neutralized by curcumin treatment. Moreover, curcumin could promote rapid phosphorylation of Akt and nuclear exclusion of FoxO1 in MIN6 cells under lipotoxic condition. Phosphatidylinositol 3-kinase and Akt specific inhibitors abolished the anti-lipotoxic effect of curcumin and stimulated FoxO1 nuclear translocation. These findings suggested that curcumin protected MIN6 pancreatic ß-Cells against apoptosis through activation of Akt, inhibition of nuclear translocation of FoxO1 and mitochondrial survival pathway.

Effect of Cichorium glandulosum on intestinal microbiota and bile acid metabolism in db/db mice.

This study aims to investigate the effects of Chorum glandulosum Boiss. et Huet (CG) on the intestinal microbiota and serum bile acid (BA) in db/db mice. A total of 12 db/db mice were randomly divided into model (MOD), high-dose CG (CGH), and control (CON) groups. The CON and MOD groups received distilled water by gavage for 8 weeks. Whereas, the CGH group received an alcohol extract of CG at a dose of 200 mg/kg/day. Results showed that CG can reduce blood lipid levels. It change the composition of the intestinal microbiota, and increase the relative abundances of Muribaculaceae, Prevotellaceae, Bifidobacterium_pseudolongum, Bacteroidaceae in db/db mice as well. LC-MS metabolomics results showed that CG adjusted the serum BA levels. The results reduced the levels of primary BAs, such as cholic acid (CA) and chenodeoxycholic acid (CDCA). The results decreased the primary BA/secondary BA (PSA/SBA) ratio in db/db mice. Correlation analysis showed that the abundances of Bifidobacterium_pseudolongum and Bacteroidaceae were positively correlated with acetic acid level and negatively correlated with ursocholic acid (UCA), α-muricholic acid (αMCA), triglyceride (TG), and total cholesterol levels (TC), indicating an interaction between the intestinal microbiota and serum BAs. CG may play a positive role in the interaction between the intestinal microbiota and BAs in lipid metabolism.

Identification of aquaporin-5 and lipid rafts in human resting saliva and their release into cevimeline-stimulated saliva.

BACKGROUND: It is unknown whether AQP5 and lipid rafts are released into human unstimulated (resting) saliva and saliva in response to secretagogues. METHODS: In order to quantitate the salivary concentration of AQP5, we produced a polyclonal antibody for human AQP5 and developed an enzyme-like immunosorbent assay (ELISA). RESULTS: AQP5 and lipid rafts were identified in human resting saliva. The amount of AQP5 in resting saliva showed a diurnal variation with high levels during waking hours, and an age-related decrease in AQP5 was coincident with the volume of resting saliva. Cevimeline, a muscarinic acetylcholine receptor (mAChR) agonist, induced the release of AQP5 with lipid rafts, amylase, mucin, and lysozyme. Changes in saliva AQP5 levels after cevimeline administration occurred simultaneously with changes in saliva flow rates. Confocal microscopy revealed that AQP5 was located in the apical plasma membrane and showed a diffuse pattern in parotid glands under resting conditions. Following cevimeline administration, AQP5 was predominantly associated with the APM and was localized in the lumen. GENERAL SIGNIFICANCE: AQP5 and lipid rafts were released with salivary proteins from human salivary glands by the stimulation of M3 mAChRs, and that changes in saliva AQP5 levels can be used as an indicator of salivary flow rate and also as a useful index of M3 mAChR agonist's action on human salivary glands.

Pancreas protective effects of Urolithin A on type 2 diabetic mice induced by high fat and streptozotocin via regulating autophagy and AKT/mTOR signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Urolithin A (UroA), the main intestinal microflora metabolite of ellagic acid of berries, pomegranate,and some other traditional chinese herbals such as emblica officinalis,etc,has been reported to exhibit anti-inflammatory, anti-oxidative, anti-tumor and pro-autophagy effects. AIM OF THE STUDY: This study evaluated the anti-diabetic and pancreas-protective effects of UroA using a mice model of type 2 diabetes and preliminarily explored its effect on autophagy as well as the mechanism involved. MATERIALS AND METHODS: Type 2 diabetes model was induced by high-fat diet (HFD; 60% energy as fat) and low-dose streptozotocin (85 mg/kg) injection. Mice were administered with UroA (50 mg/kg/d) alone or UroA-chloroquine (autophagy inhibitor) combination for 8 weeks. RESULTS: UroA improved symptoms of diabetic mice such as high water intake volume, high urine volume, significantly decreased fasting blood glucose (FBG), after-glucose-loading glucose, glycated hemoglobin (GHb) levels, plasma C-peptide, malondialdehyde (MDA) and interleukin-1 ß level, increased reduced glutathione (GSH), interleukin-10 content, and glucose tolerance. UroA also improved pancreatic function indexes such as HOMA-ß as evidenced by improved pathological and ultrastructural features of the pancreas assessed by light microscopy and transmission electron microscopy (TEM). Accordingly, UroA decreased mitochondrial swelling and myelin-like cytoplasmic inclusions. UroA significantly upregulated the protein levels of microtubule-associated protein 1 light chain 3-II (LC3II) and beclin1, downregulated sequestosome 1 (p62) accompanied by decreased expression of apoptotic protein cleaved caspase3 in pancreas of diabetic mice. In addition, it increased the phosphorylation level of protein kinase B (p-Akt) and mammalian target of rapamycin (p-mTOR). Most of these effects of UroA were reversed by treatment with autophagy inhibitor chloroquine. CONCLUSIONS: Our findings reveal that the pancreas protective effects of UroA against diabetes were partially mediated by its regulation of autophagy and AKT/mTOR signal pathway.

Flavanomarein inhibits high glucose-stimulated epithelial-mesenchymal transition in HK-2 cells via targeting spleen tyrosine kinase.

Flavanomarein (FM) is a major natural compound of Coreopsis tinctoria Nutt with protective effects against diabetic nephropathy (DN). In this study, we investigated the effects of FM on epithelial-mesenchymal transition (EMT) in high glucose (HG)-stimulated human proximal tubular epithelial cells (HK-2) and the underlying mechanisms, including both direct targets and downstream signal-related proteins. The influence of FM on EMT marker proteins was evaluated via western blot. Potential target proteins of FM were searched using Discovery Studio 2017 R2. Gene Ontology (GO) analysis was conducted to enrich the proteins within the protein-protein interaction (PPI) network for biological processes. Specific binding of FM to target proteins was examined via molecular dynamics and surface plasmon resonance analyses (SPR). FM promoted the proliferation of HK-2 cells stimulated with HG and inhibited EMT through the Syk/TGF-ß1/Smad signaling pathway. Spleen tyrosine kinase (Syk) was predicted to be the most likely directly interacting protein with FM. Combined therapy with a Syk inhibitor and FM presents significant potential as an effective novel therapeutic strategy for DN.

[Effects of aqueous extract of Hedysarum austrosibiricum on metabolism of oxyen free radicals in subacute aging mice caused by D-galactose].

OBJECTIVE: To investigate the anti-aging effect of aqueous extract of Hedysarum austrosibiricum cultivated in Xin-jiang. METHOD: Subacute aging model in mice was established by D-galactose (D-gal) and activities of SOD and GSH-PX, contents of MDA in brain and liver tissues, activities of MAO in brain tissue and immune indexes were determined. RESULT: Aqueous extract of H. austrosibiricum Xinjiang markedly increased the activities of SOD and GSH-PX, significantly decreased contents of MDA in brain and liver tissues. MAO activities in brain tissue were also decreased. It also elevated the spleen and thymus indexes. CONCLUSION: Aqueous extract of H. austrosibiricum might have anti-aging effect, which is implemented by eliminating oxyen free radicals, rising activities