RESUMO

Diabetes mellitus (DM) is associated with increased production of reactive oxygen and nitrogen species; consequently, an increase in lipid peroxidation and a decrease in antioxidants resulting in mitochondrial dysfunction. Using a rat model of DM induced by streptozotocin, we show the opposite: an increase in NO levels, S-nitrosylation, aconitase activity, and total glutathione and a decrease in lipid peroxidation at early stages of diabetes. These data imply that the decrease in lipid peroxidation is a vital early response to hyperglycemia to prevent escalation of ROS generation in mitochondria. These results also suggest a need for novel therapeutic targets to prevent the neurological consequences of diabetes.

Assuntos

Diabetes Mellitus Experimental/fisiopatologia , Mitocôndrias/fisiologia , Nitrosação , Estresse Oxidativo , Animais , Citrulina/biossíntese , Diabetes Mellitus Experimental/metabolismo , Glutationa/metabolismo , Peroxidação de Lipídeos , Masculino , Mitocôndrias/metabolismo , Ratos , Ratos Wistar , Estreptozocina

RESUMO

During the mezcal fermentation process, yeasts are affected by several stresses that can affect their fermentation capability. These stresses, such as thermal shock, ethanol, osmotic and growth inhibitors are common during fermentation. Cells have improved metabolic systems and they express stress response genes in order to decrease the damage caused during the stress, but to the best of our knowledge, there are no published works exploring the effect of oxidants and prooxidants, such as H2O2 and menadione, during growth. In this article, we describe the behavior of Kluyveromyces marxianus isolated from spontaneous mezcal fermentation during oxidative stress, and compared it with that of Saccharomyces cerevisiae strains that were also obtained from mezcal, using the W303-1A strain as a reference. S. cerevisiae strains showed greater viability after oxidative stress compared with K. marxianus strains. However, when the yeast strains were grown in the presence of oxidants in the media, K. marxianus exhibited a greater ability to grow in menadione than it did in H2O2. Moreover, when K. marxianus SLP1 was grown in a minibioreactor, its behavior when exposed to menadione was different from its behavior with H2O2. The yeast maintained the ability to consume dissolved oxygen during the 4 h subsequent to the addition of menadione, and then stopped respiration. When exposed to H2O2, the yeast stopped consuming oxygen for the following 8 h, but began to consume oxygen when stressors were no longer applied. In conclusion, yeast isolated from spontaneous mezcal fermentation was able to resist oxidative stress for a long period of time.

Assuntos

Microbiologia de Alimentos , Kluyveromyces/efeitos dos fármacos , Kluyveromyces/metabolismo , Estresse Oxidativo , Reatores Biológicos/microbiologia , Meios de Cultura/química , Peróxido de Hidrogênio/toxicidade , Kluyveromyces/isolamento & purificação , Viabilidade Microbiana/efeitos dos fármacos , Oxidantes/toxicidade , Oxirredução , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/isolamento & purificação , Saccharomyces cerevisiae/metabolismo , Vitamina K 3/toxicidade

RESUMO

Diabetes mellitus (DM) is a significant risk factor for the development of cardiovascular complications. This study was undertaken to investigate the effect of chronic administration of ethanolic extract of Eryngium carlinae on glucose, creatinine, uric acid, total cholesterol, and triglycerides levels in serum of streptozotocin- (STZ-) induced diabetic rats. Triglycerides, total cholesterol, and uric acid levels increased in serum from diabetic rats. The treatment with E. carlinae prevented these changes. The administration of E. carlinae extract reduced the levels of creatinine, uric acid, total cholesterol, and triglycerides. Thus administration of E. carlinae is able to reduce hyperlipidemia related to the cardiovascular risk in diabetes mellitus.

RESUMO

Nitric oxide (NO) is an important reactive molecule in many organisms. A mitochondrial nitric oxide synthase has been described; however, the role of NO in this organelle is not yet fully clear. We tested the effect of intramitochondrial NO on various functions from spontaneously hypertensive rats (SHR) and their normotensive genetic control, Wistar-Kyoto (WKY) rats. While the stimulation of intramitochondrial NOS increased calcium- and phosphate-induced permeability transition pore opening, its inhibition partially prevented it, without affecting membrane potential. Matrix free calcium and the pH decreased with NOS inhibition. Basal [NO] was lower in SHR than in WKY. Our data suggest that intramitochondrial NO plays an important role in mitochondrial regulation during hypertension.