phenanthrenes and Diabetes-Mellitus--Type-2

AMP-activated protein kinase (AMPK) is a central energy sensor that coordinates the response to energy challenges to maintain cellular ATP levels. AMPK is a potential therapeutic target for treating metabolic disorders, and several direct synthetic activators of AMPK have been developed that show promise in preclinical models of type 2 diabetes. These compounds have been shown to regulate AMPK through binding to a novel allosteric drug and metabolite (ADaM)-binding site on AMPK, and it is possible that other molecules might similarly bind this site. Here, we performed a high-throughput screen with natural plant compounds to identify such direct allosteric activators of AMPK. We identified a natural plant dihydrophenathrene, Lusianthridin, which allosterically activates and protects AMPK from dephosphorylation by binding to the ADaM site. Similar to other ADaM site activators, Lusianthridin showed preferential activation of AMPKβ1-containing complexes in intact cells and was unable to activate an AMPKβ1 S108A mutant. Lusianthridin dose-dependently increased phosphorylation of acetyl-CoA carboxylase in mouse primary hepatocytes, which led to a corresponding decrease in de novo lipogenesis. This ability of Lusianthridin to inhibit lipogenesis was impaired in hepatocytes from β1 S108A knock-in mice and mice bearing a mutation at the AMPK phosphorylation site of acetyl-CoA carboxylase 1/2. Finally, we show that activation of AMPK by natural compounds extends to several analogs of Lusianthridin and the related chemical series, phenanthrenes. The emergence of natural plant compounds that regulate AMPK through the ADaM site raises the distinct possibility that other natural compounds share a common mechanism of regulation.

Topics: Acetyl-CoA Carboxylase; Allosteric Regulation; AMP-Activated Protein Kinases; Animals; Binding Sites; Diabetes Mellitus, Type 2; Hepatocytes; Lipid Metabolism; Lipids; Mice; Phenanthrenes; Phosphorylation

Cryptotanshinone (CT) is a diterpene quinone compound from. This study evaluates the wound healing activity of CT by employing an excisional wound splinting model in db/db mice.. Wounds were induced at the dorsum of non-diabetic (db/+) and diabetic (db/db) mice and treated with sodium carboxymethyl cellulose (CMC-Na) or 300 mg/kg/d CT for 16 days. Wound closure was measured every two days. Body weight, fasting blood glucose, re-epithelialization, granulation, leukocyte infiltration, capillary density, collagen deposition and expressions of CXCL1, CXCL2, VEGF, Ang-1, p-eNOS, eNOS, α-SMA, MMP2 and MMP9 were analysed. Expression of VEGF and tube formation was measured. CT significantly accelerated rate of wound closure, as the contraction ratio increased from 68% (non-treated group) to 83% (CT-treated group) at days 16 post-injury. A significant increase was observed in re-epithelialization and granulation tissue formation. Mechanistically, CT suppressed leukocyte infiltration and CXCL1 and CXCL2 expression. CT treatment also increased blood vessel density and expression level of VEGF, Ang-1 and p-eNOS.. Our study provides evidence that CT could be developed as a potential therapeutic agent for the treatment of chronic diabetic wound healing.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Extracellular Matrix; Fibroblasts; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Male; Mice; Neovascularization, Physiologic; Phenanthrenes; Time Factors; Wound Healing

Polycyclic aromatic hydrocarbons (PAH) are both man-made and naturally occurring environmental pollutants that may be related to cardiometabolic health risk.. To determine whether PAH is associated with obesity in the adult population and to examine whether urinary concentrations of PAH metabolites are associated with differences in how obesity relates to 3 or more risk factors for the metabolic syndrome (3RFMetS), type 2 diabetes (T2D), hypertension, and dyslipidemia.. A total of 4765 adult participants from the 2001-2008 National Health and Nutrition Examination Survey were examined. The association between 8 urinary hydroxylated PAH metabolites, obesity, and health were examined using weighted logistic regressions adjusting for age, sex, ethnicity, PIR, smoking status, and urinary creatinine.. There was a positive dose-dependent association between obesity and 2-phenanthrene quintiles (P trend <0.0001). Contrarily, higher quintiles of 1-naphthalene were associated with lower risk of obesity (P trend = 0.0004). For a given BMI, those in the highest quintile of 2-naphthalene, 2-fluorene, 3-fluorene and 2-phenanthrene had a 66-80% greater likelihood of 3RFMetS (P≤0.05) compared to low levels. Higher quintiles of 1-naphthalene, 2-naphthalene, 2-phenanthrene and 1-pyrene were associated with a 78-124% greater likelihood of T2D (P≤0.05) compared to low levels while high 1-naphthalene, 2-naphthalene, 2-fluorene, 3-fluorene and 2-phenanthrene were associated with a 38-68% greater likelihood of dyslipidemia (P≤0.05) compared to lower levels. Finally, 2-naphthalene and 2-phenanthrene were positively associated with hypertension (P trend = 0.008 and P trend = 0.02 respectively).. PAH is related to obesity and the expression of a number of obesity-related cardiometabolic health risk factors. Future research is needed to bring to light the mechanistic pathways related to these findings.

Topics: Adult; Biomarkers; Canada; Creatinine; Diabetes Mellitus, Type 2; Dyslipidemias; Environmental Pollutants; Female; Fluorenes; Humans; Hypertension; Logistic Models; Male; Metabolic Syndrome; Middle Aged; Naphthalenes; Nutrition Surveys; Obesity; Phenanthrenes; Pyrenes; Risk

Four new polyphenols, loddigesiinols G-J (compounds 1-4) and a known compound, crepidatuol B (5), were isolated from the stems of Dendrobium loddigesii that have long been used in Traditional Chinese Medicine and have recently been used to treat type 2 diabetes. Compounds 1-5 structures were elucidated based on spectroscopic analysis. The absolute configurations of compounds 1-4 were determined using theoretical calculations of electronic circular dichroism (ECD), and the absolute configuration of compound 5 was determined by a comparison of the experimental ECD spectra and the literature data. Compounds 1-5 are strong inhibitors of α-glucosidase, with IC50 values of 16.7, 10.9, 2.7, 3.2, and 18.9 μM, respectively. Their activities were significantly stronger than trans-resveratrol as a positive control (IC50 values of 27.9 μM).

Topics: alpha-Glucosidases; Dendrobium; Diabetes Mellitus, Type 2; Enzyme Inhibitors; Glycoside Hydrolase Inhibitors; Medicine, Chinese Traditional; Molecular Structure; Phenanthrenes; Plant Extracts; Plant Stems; Polyphenols

To investigate the protective effect of combination of triptolide and irbesartan on the podocytes in a type 2 diabetic(T2DM) rat model, and evaluate its mechanism.. T2DM rats were induced by fed with high-sucrose-high-fat diet combined with a low dose of streptozocin. The rats were randomly divided into 5 groups: normal control group (NC, n = 10), diabetes group (DM, n = 11), triptolide treatment group (DT, n = 12), irbesartan treatment group (DI, n = 12) and triptolide combined with irbesartan treatment group (DTI, n = 13). Ultrastructure of podocytes was observed by electronic microscopy and urinary albumin (UAL) excretion by ELISA was determined after 8 weeks. The expression of nephrin and bone morphogenetic protein-7 (BMP-7), connective tissue growth factor (CTGF), transforming growth factor (TGF)β(1) mRNA and proteins were detected by immunohistochemistry, real-time PCR and Western blot.. Increased UAL was significantly attenuated in all treatment groups. Compared to NC group, UAL in DM group was increased significantly (0.45 ± 0.09 vs 6.36 ± 0.87, P < 0.01), while decreased in triptolide or irbesartan alone treatment group (2.48 ± 0.37 and 2.68 ± 0.42, both P < 0.01). Compared with those in control groups, kidney expression of nephrin, BMP-7 mRNA and proteins were downregulated while CTGF, TGFβ(1) mRNA and proteins were significantly upregulated in T2DM rats. Triptolide or irbesartan each alone moderately ameliorated albuminuria and podocyte damage. However, their combined usage showed a dramatic therapeutic synergism, manifested by prevention of progressive albuminuria, restoration of the glomerular filtration barrier, reversal of the decline in slit diaphragm proteins, reduction expression of CTGF, TGFβ(1), and upregulation of BMP-7.. Our findings show that triptolide can increase the efficacy of irbesartan, leading to a more effective prevention of kidney disease in T2DM rat model, which may through upregulation of BMP-7 and inhibition the over-expression of CTGF and TGFβ(1).

Topics: Animals; Biphenyl Compounds; Bone Morphogenetic Protein 7; Connective Tissue Growth Factor; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Diterpenes; Epoxy Compounds; Irbesartan; Male; Phenanthrenes; Podocytes; Rats; Rats, Wistar; Tetrazoles; Transforming Growth Factor beta1

The activation of the poly(ADP-ribose) polymerase (PARP) plays an important role in the pathophysiology of various diseases associated with oxidative stress. We found increased amounts of poly(ADP) ribosylated proteins in diabetic kidneys of Lepr(db/db) (BKsJ) mice, suggesting increased PARP activity. Therefore, we examined the effects of two structurally unrelated PARP inhibitors (INO-1001 and PJ-34) on the development of diabetic nephropathy of Lepr(db/db) (BKsJ) mice, an experimental model of type 2 diabetes. INO-1001 and PJ-34 were administered in the drinking water to Lepr(db/db) mice. Both INO-1001 and PJ-34 treatment ameliorated diabetes-induced albumin excretion and mesangial expansion, which are hallmarks of diabetic nephropathy. PARP inhibitors decreased diabetes-induced podocyte depletion in vivo and blocked hyperglycemia-induced podocyte apoptosis in vitro. High glucose treatment of podocytes in vitro led to an early increase of poly(ADP) ribosylated modified protein levels. Reactive oxygen species (ROS) generation appears to be a downstream target of hyperglycemia-induced PARP activation, as PARP inhibitors blocked the hyperglycemia-induced ROS generation in podocytes. INO-1001 and PJ-34 also normalized the hyperglycemia-induced mitochondrial depolarization. PARP blockade by INO-1001 and PJ-34 prevented hyperglycemia-induced nuclear factor-kappaB (NFkappaB) activation of podocytes, and it was made evident by the inhibitor of kappaBalpha phosphorylation and NFkappaB p50 nuclear translocation. Our results indicate that hyperglycemia-induced PARP activation plays an important role in the pathogenesis of glomerulopathy associated with type 2 diabetes and could serve as a novel therapeutic target.

Topics: Animals; Apoptosis; Blood Pressure; Body Weight; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Enzyme Activation; Indoles; Kidney; Mice; Phenanthrenes; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Reactive Oxygen Species; Receptors, Cell Surface; Receptors, Leptin