Protofibril formation: decreased total glutathione concentration as an early indicator of neuron damage in the brainstems of Wistar rats treated with rotenone

Background: Rotenone treatment causes oxidative stress in neurons and forms the basis of animal models of Parkinson's disease. The reduced form of glutathione is predicted to detoxify rotenone from neurons in the brainstem. This study aims to measure the concentration of total glutathione and analyze the formation of protofibril in the brainstem of Wistar rats treated with rotenone. Methods: Seventy-two male Wistar rats aged 8–9 weeks weighing 200–250 g were divided into two investigations: total glutathione determination and protofibril analysis. The independent variables were treatment group, observation time, and location in the brainstem. The dependent variables were the concentration of total glutathione and protofibril density. Results: The concentration of total glutathione was not significantly different among treatment groups (p: 0.084), observation time (p: 0.608), or the location in the brainstem (p: 0.372). Protofibril density was different in the treatment groups (p: 0.001), observation time (p: 0.001), and between the upper and lower brainstem (p: 0.001). Rotenone treatment subcortically induced the concentration of total glutathione in the brainstem to decrease, but protofibril density tended to increase. Conclusions: The total glutathione concentration is inversely proportional to protofibril density. Total glutathione might be an early marker of neuronal damage.

Histopathological and biochemical effect of quercetin on monosodium glutamate supplementation-induced testicular toxicity

Background Despite the wide usage of monosodium glutamate (MSG) as a flavor enhancer in many types of food, it has been reported as a toxic agent to humans and experimental animals. It also adversely influences male fertility. Several research studies attributed detrimental effects of MSG on reproductive organs to oxidative stress. The current study investigated the effects of MSG on testis and the potential role of quercetin in attenuating them. Results MSG-treated rats showed a considerable elevation in lipid peroxidation level and reduction in glutathione concentration, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities in the homogenate of testis tissues. Treatment with quercetin in combination with MSG provided significant protection. When QU was used, the toxic side effects were significantly reduced, with a considerable reduction in lipid peroxidation and an increase in SOD and GPx activities, and glutathione concentration. Conclusions Quercetin may be used in combination with MSG to improve the histopathological, ultrastructure, oxidative stress, and biochemical parameters of testicular toxicity induced by MSG due to its antioxidant effects. Graphical abstract

Effect of extremely low frequency magnetic fields on oxidative balance in rat brains subjected to an experimental model of chronic unpredictable mild stress

Background There has been an increasing interest in researching on the effects of extremely low-frequency magnetic fields on living systems. The mechanism of action of extremely low-frequency magnetic fields on organisms has not been established. One of the hypotheses is related to induce changes in oxidative balance. In this study, we measured the effects of chronic unpredictable mild stress induced-oxidative balance of rat’s brain exposed to extremely low-frequency magnetic fields. Methods A first experiment was conducted to find out if 14 days of chronic unpredictable mild stress caused oxidative unbalance in male Wistar rat’s brain. Catalase activity, reduced glutathione concentration, and lipoperoxidation were measured in cerebrum and cerebellum. In the second experiment, we investigate the effects of 7 days extremely low-frequency magnetic fields exposure on animals stressed and unstressed. Results The main results obtained were a significant increase in the catalase activity and reduced glutathione concentration on the cerebrum of animals where the chronic unpredictable mild stress were suspended at day 14 and then exposed 7 days to extremely low-frequency magnetic fields. Interestingly, the same treatment decreases the lipoperoxidation in the cerebrum. The stressed animals that received concomitant extremely low frequency magnetic fields exposure showed an oxidative status like stressed animals by 21 days. Thus, no changes were observed on the chronic unpredictable mild stress induced-oxidative damage in the rat’s cerebrum by the extremely low-frequency magnetic field exposure together with chronic unpredictable mild stress. Conclusions The extremely low-frequency electromagnetic field exposure can partially restore the cerebrum antioxidant system of previously stressed animals.

Characterization of ferroptosis in kidney tubular cell death under diabetic conditions

Kidney tubular cell death induced by transforming growth factor-β1 (TGF-β1) is known to contribute to diabetic nephropathy, a major complication of diabetes. Caspase-3-dependent apoptosis and caspase-1-dependent pyroptosis are also involved in tubular cell death under diabetic conditions. Recently, ferroptosis, an atypical form of iron-dependent cell death, was reported to cause kidney disease, including acute kidney injury. Ferroptosis is primed by lipid peroxide accumulation through the cystine/glutamate antiporter system Xc− (xCT) and glutathione peroxidase 4 (GPX4)-dependent mechanisms. The aim of this study was to evaluate the role of ferroptosis in diabetes-induced tubular injury. TGF-β1-stimulated proximal tubular epithelial cells and diabetic mice models were used for in vitro and in vivo experiments, respectively. xCT and GPX4 expression, cell viability, glutathione concentration, and lipid peroxidation were quantified to indicate ferroptosis. The effect of ferroptosis inhibition was also assessed. In kidney biopsy samples from diabetic patients, xCT and GPX4 mRNA expression was decreased compared to nondiabetic samples. In TGF-β1-stimulated tubular cells, intracellular glutathione concentration was reduced and lipid peroxidation was enhanced, both of which are related to ferroptosis-related cell death. Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, alleviated TGF-β1-induced ferroptosis. In diabetic mice, kidney mRNA and protein expressions of xCT and GPX4 were reduced compared to control. Kidney glutathione concentration was decreased, while lipid peroxidation was increased in these mice, and these changes were alleviated by Fer-1 treatment. Ferroptosis is involved in kidney tubular cell death under diabetic conditions. Ferroptosis inhibition could be a therapeutic option for diabetic nephropathy.

Effect of vine-shoot and oak extract foliar grapevine applications on oenological parameters, phenolic acids and glutathione content of white musts and wines

Aim: An oxidation process frequently occurs during white winemaking, affecting its quality. The aim was to study, for two years (2013 and 2014), the effects that foliar applications of vine-shoot (Airén (AVS) and Moscatel (MVS)) and oak wood (OW) extracts on Airén grapevines have on wine color, and must and wine glutathione, trans-GRP, trans-caftaric acid, and trans-p-coutaric acid content.Methods and results: These compounds were analyzed by HPLC. The results showed that, in general, foliar application of Airén vine-shoot extracts did not affect glutathione concentration, and the other treatments decreased it. AVS2013-50 and AVS2014 samples were characterized by a high content of glutathione and trans-GRP, while MVS2014 samples retain high levels of trans-caftaric acid. trans-p-Coutaric acid concentration decreased after AVS2013 treatment, meanwhile in the 2014 season all applications increased its content. The content of these compounds in the wines was similar to those obtained in the musts. OW2013 showed the lowest value of Abs 420, likely because this treatment decreased glutathione concentration in musts.Conclusions: The foliar applications of vine-shoots and oak extracts on Airén grapevines had a clear effect in reducing the wine alcohol degree and Baumé in case of grapes. This finding is interesting in the context of the current global warming change scenario. Although the two vintages studied were different, an improvement in the color quality was observed in both. The content of glutathione decreased from must to wine: the content in both matrices was lower in treated samples than in control samples, except for Airén extracts in both vintages. This means that glutathione is oxidized, avoiding the oxidation of other must and wine molecules.Significance and impact of the study: These findings are important in relation to revalorizing waste from the vineyard, and thus being able to improve the quality of the white wine in relation to the oxidation processes that take place in the winemaking process.