Signaling mechanisms of a water soluble curcumin derivative in experimental type 1 diabetes with cardiomyopathy

BACKGROUND: Curcumin exhibits anti-diabetic activities, induces heme-oxygenase-1 (HO-1) and is an inhibitor of transcriptional co-activator p300. A novel water soluble curcumin derivative (NCD) has been developed to overcome low invivo bioavailability of curcumin. We evaluated the effect of the NCD on signaling mechanisms involved in cardiomyocyte hypertrophy and studied whether its action is mediated via inducible HO-1. MATERIALS AND METHODS: Rats were divided into controls, controls receiving NCD, diabetic, diabetic receiving NCD, diabetic receiving pure curcumin, diabetic receiving HO inhibitor, zinc protoporphyrin IX (ZnPP IX) and diabetic receiving NCD and ZnPP IX. NCD and curcumin were given orally. After 45 days, cardiac physiologic parameters, plasma glucose, insulin, glycated hemoglobin (GHb), HO-1 gene expression and HO activity in pancreas and cardiac tissues were assessed. Gene expression of p300, atrial natriuretic peptide (ANP) and myocyte enhancer factor 2 (MEF2A and MEF2C) were studied. RESULTS: NCD and curcumin decreased plasma glucose, GHb and increased insulin levels significantly in diabetic rats. This action may be partially mediated by induction of HO-1 gene. HO-1 gene expression and HO activity were significantly increased in diabetic heart and pancreas. Diabetes upregulated the expression of ANP, MEF2A, MEF2C and p300. NCD and curcumin prevented diabetes-induced upregulation of these parameters and improved left ventricular function. The effect of the NCD was better than the same dose of curcumin

A comparative study of metabolic effects of the corpus allatum in two adult Coleoptera, in relation to diapause

Two problems were studied: a) Whether a lower titre of the corpus allatum hormone had a different influence on the tissues of an adult insect with a diapause mechanism than on those of one without a diapause. b) Whether the metabolic effects of the corpus allatum hormone were caused mainly by its indirect influence upon an organ, e.g. the ovary, or by general influence on the metabolism as a whole. For the research two adult Coleoptera were used: the Colorado beetle (Leptinotarsa decemlineata Say) with a diapause mechanism and the yellow mealworm beetle (Tenebrio molitor L.) without such a mechanism. By tracing the influences of allatectomy or of castration on the respiration it was concluded that in both species the hormone had a gonadotropic influence in females and in♂and♀Colorado beetles also a general influence on the metabolism (direct on the basal resting respiration of active insects and probably indirect on their respiration by forced action through the central nerve system).Further hypotheses were drafted about the location of the diapause mechanism (the flight muscles and the fat body?) and the function of the corpus allatum in the fat metabolism (probably mainly to speed the making of fatty acids unsaturated)