Arctigenin Efficiently Enhanced Sedentary Mice Treadmill Endurance

Physical inactivity is considered as one of the potential risk factors for the development of type 2 diabetes and other metabolic diseases, while endurance exercise training could enhance fat oxidation that is associated with insulin sensitivity improvement in obesity. AMP-activated protein kinase (AMPK) as an energy sensor plays pivotal roles in the regulation of energy homeostasis, and its activation could improve glucose uptake, promote mitochondrial biogenesis and increase glycolysis. Recent research has even suggested that AMPK activation contributed to endurance enhancement without exercise. Here we report that the natural product arctigenin from the traditional herb Arctium lappa L. (Compositae) strongly increased AMPK phosphorylation and subsequently up-regulated its downstream pathway in both H9C2 and C2C12 cells. It was discovered that arctigenin phosphorylated AMPK via calmodulin-dependent protein kinase kinase (CaMKK) and serine/threonine kinase 11(LKB1)-dependent pathways. Mice treadmill based in vivo assay further indicated that administration of arctigenin improved efficiently mice endurance as reflected by the increased fatigue time and distance, and potently enhanced mitochondrial biogenesis and fatty acid oxidation (FAO) related genes expression in muscle tissues. Our results thus suggested that arctigenin might be used as a potential lead compound for the discovery of the agents with mimic exercise training effects to treat metabolic diseases

Current and Future Drug Targets in Weight Management

Obesity will continue to be one of the leading causes of chronic disease unless the ongoing rise in the prevalence of this condition is reversed. Accumulating morbidity figures and a shortage of effective drugs have generated substantial research activity with several molecular targets being investigated. However, pharmacological modulation of body weight is extremely complex, since it is essentially a battle against one of the strongest human instincts and highly efficient mechanisms of energy uptake and storage. This review provides an overview of the different molecular strategies intended to lower body weight or adipose tissue mass. Weight-loss drugs in development include molecules intended to reduce the absorption of lipids from the GI tract, various ways to limit food intake, and compounds that increase energy expenditure or reduce adipose tissue size. A number of new preparations, including combinations of the existing drugs topiramate plus phentermine, bupropion plus naltrexone, and the selective 5-HT2C agonist lorcaserin have recently been filed for approval. Behind these leading candidates are several other potentially promising compounds and combinations currently undergoing phase II and III testing. Some interesting targets further on the horizon are also discussed

Regulation of Human and Pig Renal Na+,K+-ATPase Activity by Tyrosine Phosphorylation of Their a1-Subunits

Abstract Modulation of the physiologically influential Na?,K?-ATPase is a complex process involving a wide variety of factors. To determine the possible effects of the protein tyrosine phosphatase (PTP) inhibitors dephostatin and Et-3,4-dephostatin on human and pig, renal cells and enzymatic extracts, we treated our samples (15 min–24 h) with those PTP inhibitors (0–100 lM). PTP inhibitors were found to possess a concentration-dependent inhibition of Na,K-ATPase activity in both human and pig samples.The inhibition was similarly demonstrated on all cellular, microsomal fraction and purified Na,K-ATPase levels.Despite rigorous activity recovery attempts, the PTP inhibitors’ effects were sustained on Na?,K?-ATPase activity. Western blotting experiments revealed the expression of both a1- and b1-subunits in both human and pig tissues. a1-Subunits possessed higher tyrosine phos- phorylation levels with higher concentrations of PTP inhibitors. Meanwhile, serine/threonine residues of both a1- and b1-subunits demonstrated diminished phosphorylation levels upon dephostatin treatment. Accordingly, we pro-vide evidence that Na?,K?-ATPase can be regulated through tyrosine phosphorylation of primarily their subunits, using PTP inhibitors