Antioxidant and Anticancer Activities and Protein Interaction of the Oxidovanadium(IV) Naringin Complex

The complex of oxidovanadium(IV) with naringin (Narg) [VO(Narg)2] 8H2O (VONarg) was prepared according to the literature improving the synthetic procedure and physicochemical characterization. In addition, biological activities (cytotoxic, antioxidant, and BSA interaction) were determined. The metal coordinated through the 5-hydroxy and 4-carbonyl groups of rings A and C of naringin, respectively. The antioxidant activity of VONarg, determined in vitro, was higher than those of the flavonoid against superoxide and peroxyl reactive oxygen species (ROS) and DPPH radical. The cytotoxic properties were determined by a MTT assay on adenocarcinoma human alveolar basal epithelial cells (A549). VONarg exerted a 20% decrease in cancer cells viability at 24 h incubation, while naringin and oxidovanadium(IV) cation did not show cytotoxicity. Measurements with the normal HEK293 cell line showed that the inhibitory action of the complex is selective. VONarg generated intracellular reactive oxygen species (ROS), depletion of reduced glutathione and depolarization of mitochondrial membrane potential, typical for apoptotic pathway, producing cell death by oxidative stress mechanism. Moreover, naringin interacted with bovine serum albumin (BSA) through hydrophobic interactions in a spontaneous process, and VONarg showed greater affinity for the protein but can still be transported and delivered by it (Ka 104 L·mol−1 order).

Effects of Endurance Training on the Coenzyme Q Redox State in Rat Heart, Liver and Brain at the Tissue and Mitochondrial Levels: Implications for Reactive Oxygen Species Formation and Respiratory Chain Remodeling

Sixteen adult, 4-month-old male Wistar rats were randomly assigned to the training group (n = 8) or the control group (n = 8). We elucidated the effects of 8 weeks of endurance training on coenzyme Q (Q) content and the formation of reactive oxygen species (ROS) at the tissue level and in isolated mitochondria of the rat heart, liver and brain. We demonstrated that endurance training enhanced mitochondrial biogenesis in all tested organs, while a significant increase in the Q redox state was observed in the heart and brain, indicating an elevated level of QH2 as an antioxidant. Moreover, endurance training increased the mQH2 antioxidant pool in the mitochondria of the heart and liver, but not in the brain. At the tissue and isolated mitochondria level, an increase in ROS formation was only observed in the heart. ROS formation observed in the mitochondria of individual rat tissues after training may be associated with changes in the activity/amount of individual components of the oxidative phosphorylation system and its molecular organization, as well as with the size of the oxidized pool of mitochondrial Q acting as an electron carrier in the respiratory chain. Our results indicate that tissue-dependent changes induced by endurance training in the cellular and mitochondrial QH2 pool acting as an antioxidant and in the mitochondrial Q pool serving the respiratory chain may serve important roles in energy metabolism, redox homeostasis and the level of oxidative stress.

Control of Reactive Oxygen Species through Antioxidant Enzymes Plays a Pivotal Role during the Cultivation of Neopyropia yezoensis

Neopyropia yezoensis is an economically important marine crop that can survive dehydrating conditions when nets are lifted from seawater. During this process, production of oxygen radicals and the resulting up-regulation of antioxidant enzymes mediated by the abscisic acid (ABA) signaling pathway played an important role. However, there were no reports about the significance regarding the protection of seaweed throughout the entire production season. Especially, in new aquatic farms in Shandong Province that were formed when traditional N. yezoensis cultivation moved north. Here, we determined the levels of ABA, hydrogen peroxide (H2O2), soluble protein, chlorophyll, and cell wall polysaccharides in samples collected at different harvest periods from Jimo aquatic farm, Shandong Province. The activities and expression of NADPH oxidase (NOX) and antioxidant enzymes in the corresponding samples were also determined. Combined with the monitoring data of sea surface temperature and solar light intensity, we proposed that the cultivation of N. yezoensis in Shandong Province was not affected by high-temperature stress. However, photoinhibition in N. yezoensis usually occurs at noon, especially in March. Both the activities and the expression of NOX and antioxidant enzymes were up-regulated continuously. It is reasonable to speculate that the reactive oxygen species (ROS) produced by NOX induced the up-regulation of antioxidant enzymes through the ABA signaling pathway. Although antioxidant enzymes play a pivotal role during the cultivation of N. yezoensis, the production of ROS also caused a shift in gene expression, accumulation of secondary metabolites, and even decreased the chlorophyll pool size, which eventually led to a decrease in algae assimilation. Accordingly, we suggest that the dehydration of N. yezoensis nets should be adopted when necessary and the extent of dehydration should be paid special consideration to avoid an excessive cellular response caused by ROS.

Guilingji Protects Against Spermatogenesis Dysfunction From Oxidative Stress via Regulation of MAPK and Apoptotic Signaling Pathways in Immp2l Mutant Mice

Male infertility is a major health issue with an estimated prevalence of 4.2% of male infertility worldwide. Oxidative stress (OS) is one of the main causes of male infertility, which is characterized by excessive reactive oxygen species (ROS) or lack of antioxidants. Meanwhile, it is reported that oxidative stress plays an important role in the spermatogenic impairment in Inner mitochondrial membrane peptidase 2-like (Immp2l) mutant mice. In this study, we focused on the potential mechanism of Guilingji in protecting the spermatogenic functions in Immp2l mutant mice. The results revealed that Immp2l mutant mice exhibit impaired spermatogenesis and histology shows seminiferous tubules with reduced spermatogenic cells. After administration of Guilingji [150 mg/kg per day intragastric gavage], however, alleviated spermatogenesis impairment and reversed testis histopathological damage and reduced apoptosis. What’s more, western blotting and the levels of redox classic markers revealed that Guilingji can markedly reduce reactive oxygen species. Moreover, Guilingji treatment led to inhibition of the phosphorylation of mitogen-activated protein kinase (MAPK), regulated apoptosis in the cells. In summary, Guilingji can improve spermatogenesis in Immp2l mutant mice by regulating oxidation-antioxidant balance and MAPK pathway. Our data suggests that Guilingji may be a promising and effective antioxidant candidate for the treatment of male infertility.

Production of hydrogen peroxide in an intra-meander hyporheic zone at East River, Colorado

The traditionally held assumption that photo-dependent processes are the predominant source of H2O2 in natural waters has been recently questioned by an increrasing body of evidence showing the ubiquitiousness of H2O2 in dark water bodies and in groundwater. In this study, we conducted field measurement of H2O2 in an intra-meander hyporheic zone and in surface water at East River, CO. On-site detection using a sensitive chemiluminescence method suggests H2O2 concentrations in groundwater ranging from 6 nM (at the most reduced region) to ~ 80 nM (in a locally oxygen-rich area) along the intra-meander transect with a maxima of 186 nM detected in the surface water in an early afternoon, lagging the maximum solar irradiance by ∼ 1.5 h. Our results suggest that the dark profile of H2O2 in the hyporheic zone is closely correlated to local redox gradients, indicating that interactions between various redox sensitive elements could play an essential role. Due to its transient nature, the widespread presence of H2O2 in the hyporheic zone indicates the existence of a sustained balance between H2O2 production and consumption, which potentially involves a relatively rapid succession of various biogeochemically important processes (such as organic matter turnover, metal cycling and contaminant mobilization). More importantly, this study confirmed the occurrence of reactive oxygen species at a subsurface redox transition zone and further support our understanding of redox boundaries on reactive oxygen species generation and as key locations of biogeochemical activity.