Rutin administration attenuates myocardial dysfunction in diabetic rats

Oxidative stress plays a major role in diabetic cardiomyopathy pathogenesis. Anti-oxidant therapy has been investigated in preventing or treating several diabetic complications. However, anti-oxidant action on diabetic-induced cardiac remodeling is not completely clear. This study evaluated the effects of rutin, a flavonoid, on cardiac and myocardial function in diabetic rats. Wistar rats were assigned into control (C, n = 14); control-rutin (C-R, n = 14); diabetes mellitus (DM, n = 16); and DM-rutin (DM-R, n = 16) groups. Seven days after inducing diabetes (streptozotocin, 60 mg/kg, i.p.), rutin was injected intraperitoneally once a week (50 mg/kg) for 7 weeks. Echocardiogram was performed and myocardial function assessed in left ventricular (LV) papillary muscles. Serum insulin concentration was measured by ELISA. One-way ANOVA and Tukey's post hoc test. Glycemia was higher in DM than DM-R and C and in DM-R than C-R. Insulin concentration was lower in diabetic groups than controls (C 2.45 ± 0.67; C-R 2.09 ± 0.52; DM 0.59 ± 0.18; DM-R 0.82 ± 0.21 ng/mL). Echocardiogram showed no differences between C-R and C. DM had increased LV systolic diameter compared to C, and increased left atrium diameter/body weight (BW) ratio and LV mass/BW ratio compared to C and DM-R. Septal wall thickness, LV diastolic diameter/BW ratio, and relative wall thickness were lower in DM-R than DM. Fractional shortening and posterior wall shortening velocity were lower in DM than C and DM-R. In papillary muscle preparation, DM and DM-R presented higher time to peak tension and time from peak tension to 50% relaxation than controls; time to peak tension was lower in DM-R than DM. Under 0.625 and 1.25 mM extracellular calcium concentrations, DM had higher developed tension than C. Rutin attenuates cardiac remodeling and left ventricular and myocardial dysfunction caused by streptozotocin-induced diabetes mellitus.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Pró-Reitoria de Pesquisa da UNESP (PROPe)Departamento de Medicina Interna, Faculdade de Medicina de Botucatu (FMB), Universidade Estadual Paulista (UNESP), Botucatu, SP, BrasilDepartamento de Química e Bioquímica, Instituto de Biociências de Botucatu (IBB), Universidade Estadual Paulista (UNESP), Botucatu, SP, BrasilDepartamento de Clínica Médica, Faculdade de Medicina de Botucatu (FMB), Universidade Estadual Paulista (UNESP), Botucatu, SP, BrasilUniversidade Estadual Paulista, Departamento de Clínica Médica, Faculdade de Medicina de BotucatuUniversidade Estadual Paulista, Departamento de Química e Bioquímica, Instituto de Biociências de BotucatuCNPq: 306845/2012-1CNPq: 306857/2012-0)FAPESP: 2009/54506-

Apocynin influence on oxidative stress and cardiac remodeling of spontaneously hypertensive rats with diabetes mellitus

Abstract Purpose Although increased oxidative stress is a major component of diabetic hypertensive cardiomyopathy, research into the effects of antioxidants on cardiac remodeling remains scarce. The actions of antioxidant apocynin include inhibiting reactive oxygen species (ROS) generation by nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and ROS scavenging. We evaluated the effects of apocynin on cardiac remodeling in spontaneously hypertensive rats (SHR) with diabetes mellitus (DM). Methods Male SHR were divided into four groups: control (SHR, n = 16); SHR treated with apocynin (SHR-APO; 16 mg/kg/day, added to drinking water; n = 16); diabetic SHR (SHR-DM, n = 13); and SHR-DM treated with apocynin (SHR-DM-APO, n = 14), for eight weeks. DM was induced by streptozotocin (40 mg/kg, single dose). Statistical analyzes: ANOVA and Tukey or Mann–Whitney. Results Echocardiogram in diabetic groups showed higher left ventricular and left atrium diameters indexed for body weight, and higher isovolumetric relaxation time than normoglycemic rats; systolic function did not differ between groups. Isolated papillary muscle showed impaired contractile and relaxation function in diabetic groups. Developed tension was lower in SHR-APO than SHR. Myocardial hydroxyproline concentration was higher in SHR-DM than SHR, interstitial collagen fraction was higher in SHR-DM-APO than SHR-APO, and type III collagen protein expression was lower in SHR-DM and SHR-DM-APO than their controls. Type I collagen and lysyl oxidase expression did not differ between groups. Apocynin did not change collagen tissue. Myocardial lipid hydroperoxide concentration was higher in SHR-DM than SHR and SHR-DM-APO. Glutathione peroxidase activity was lower and catalase higher in SHR-DM than SHR. Apocynin attenuated antioxidant enzyme activity changes in SHR-DM-APO. Advanced glycation end-products and NADPH oxidase activity did not differ between groups. Conclusion Apocynin reduces oxidative stress independently of NADPH oxidase activity and does not change ventricular or myocardial function in spontaneously hypertensive rats with diabetes mellitus. The apocynin-induced myocardial functional impairment in SHR shows that apocynin actions need to be clarified during sustained chronic pressure overload

Unique Vascular Benefits of Estetrol, a Native Fetal Estrogen with Specific Actions in Tissues (NEST)

peer reviewedEstrogens (E), in combination with oral contraceptives (COCs) and hormone replacement therapy (HRT) drugs used for the relief of climacteric symptoms of menopause, increase the synthesis of clotting factors, decrease the levels of coagulation inhibitors, and increase the risk of venous thromboembolic events (VTE). Ischemic stroke incidence in postmenopausal women during HRT use is also increased and is probably due to a thrombotic event. This suggests that a safer estrogen may reduce stroke and VTE incidence, with lower impact on hemostasis. Estetrol (E4) is a relatively recently described new human-specific E produced exclusively by the fetal liver during pregnancy. This Native (human and natural) E has Selective actions in Tissues (NEST). Nest activities of E4 are the consequence of its unique dual role. It activates the nuclear estrogen receptor alpha (ERα) but antagonizes the membrane ERα in contrast to other E, which activate both types of receptors. Most beneficial effects of E on the vascular system have been ascribed to the activation of the membrane ERα of vascular endothelial cells, including enhancement of nitric oxide (NO) production, vasodilation, and prevention of atherosclerosis, of neointimal proliferation, and of hypertension. In a series of papers reviewed here, the INSERM team in Toulouse has demonstrated, by the combined use of pharmacological tools and of transgenic mice lacking either the nuclear ERα, the membrane ERα, or both, that the nuclear ERα plays a major role in controlling E activities in vessels. E4 is able to elicit the important vasculoprotective actions mediated by estradiol (E2). Furthermore, phase 1 and 2 clinical studies of E4 in a contraceptive indication (in combination with drospirenone) or in postmenopausal women for the relief of climacteric complaints demonstrate that E4 has a minimal impact on hemostasis, coagulation factors, coagulation inhibitors, fibrinolysis, angiotensinogen, triglycerides, and cholesterol. Altogether, preclinical studies and phase 1 and 2 clinical data indicate that E4 could be a new E with a better safety/efficacy profile than other E for women’s healthcare