Antioxidant enzymes and vascular diseases

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) play a fundamental role in regulating endothelial function and vascular tone in the physiological conditions of a vascular system. However, oxidative stress has detrimental effects on human health, and numerous studies confirmed that high ROS/RNS production contributes to the initiation and progression of cardiovascular diseases. The antioxidant defense has an essential role in the homeostatic functioning of the vascular endothelial system. Endogenous antioxidative defense includes various molecules and enzymes such as superoxide dismutase, catalase, glutathione reductase, and glutathione peroxidase. Together all these antioxidative enzymes are essential for defense against harmful ROS features. ROS are mainly generated from redox-active compounds involved in the mitochondrial respiratory chain. Thus, targeting antioxidative enzymes and mitochondria oxidative balance may be a promising approach for vascular diseases occurrence and treatment. This review summarized the most recent research on the regulation of antioxidative enzymes in vascular diseases.

Evaluation of Oxidative Stress in Azoxymethane-induced Colon Cancerous Fischer Rats

Objective: to study the redox status of normal colon and aberrant crypts formed in azoxymethane induced colon cancerous fischer rats. Methods A total of 16 five-week-old male Fisher 344 rats (Rattus norvegicus), weighing approximately 90–100 grams were housed individually in plastic cages with wood-chip bedding. The animals were acclimatized for 1 week and fed with an American Institute of Nutrition (AIN-93G) diet ad libitum. Their protein oxidation, DNA damage, lipid peroxidation and antioxidants, glutathione (GSH), and antioxidative enzymes in serum were detected. Results The levels of protein oxidation Sand lipid peroxidation were significantly higher in the study group than in the control group (P<0.01). However, the mean serum level of MDA and conjugated diene was lower in the study group than in the control group (P<0.01). The activity of antioxidative enzymes was significantly decreased in the study group compared to control group (P<0.01). Conclusion Colorectal cancer is associated with oxidative stress, and assessment of oxidative stress and given antioxidants is important for the treatment and prevention of colorectal cancer.

Oxidative Stress Induced by Exposure of Microplastics in Labeo Rohita

The present study revealed the oxidative stress induced by the exposure of low density polyethylene microplastics (LDPE MPs) in Labeo rohita. Fingerlings were divided into four (control, T1, T2 and T3) groups. Fingerlings of T1, T2 and T3 groups were exposed respectively to 2, 20 and 200 mg/L of LDPE MPs for 45 days. A control was also maintained during experiment to which no MPs were added. Oxidative stress studies revealed a decrease in the activity of hepatic antioxidative enzymes i.e. superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) in all treated groups in dose and time dependent manner. In gills, an increase in the activities of SOD, CAT and GPx but decrease in the activities of GR and GST was found in T1 group after 30 days of exposure. However, decrease in activities of these enzymes was observed in all treated groups in dose dependent manner after 45 days of exposure. Moreover, the activities of antioxidative enzymes were found to be decreased in time dependent manner. In kidneys, increase in the activities of antioxidative enzymes was observed in T1 group followed by their decrease in T2 and T3 groups in dose and time dependent manner. However, Lipid peroxidation was found to be increased in vital organs of all treated groups in dose and time dependent manner indicating MPs induced oxidative stress in these organs due to increased production of reactive oxygen species.

HEAT STRESS-INDUCED ALTERATIONS IN ANTIOXIDATIVE ENZYMES OF SOME PLANTS OF CUCURBITACEA FAMILY

The effects of high temperatures on melon cvs. Miranda and Poli, watermelon cv. Crimson Tide and zucchini cv. Asma leaves. The leaves obtained from plants were subjected to 35, 40, 45, 50, 55 and 60°C temperatures with gradual increments every 30-minutes. Samples, obtained at each treatment, were analyzed for ascorbic acid content, NADP(H) oxidase, catalase, gluthatione reductase, peroxidases activities and isoperoxidase patterns. The ascorbic acid content slightly increased parallel to temperature increment in zucchini but did not change in watermelon and in both melon cultivars. Melon cv. Poli exhibited comparatively less oxidative damage than cv. Miranda with a lower NAD(P)H oxidase activity. Heat stress induced NAD(P)H activity in watermelon and zucchini comparing to control plants. Results revealed that antioxidative enzyme activities were increased generally up to 50°C then decreased gradually in melon cultivars. Besides cv. Poli generally had higher enzyme activities than cv. Miranda. The activity of catalaes become prominent in watermelon while the activity of ascorbate peroxidase become prominent in zucchini. Acidic isoperoxidase bands with different relative mobility values were found in all species. Besides, basic isoperoxidase band could not be determined in both melon cultivars and watermelon while a basic isoperoxidase band was found in zucchini.

Effect of drought on photosynthesis, total antioxidant capacity, bioactive component accumulation, and the transcriptome of Atractylodes lancea

Background Atractylodes lancea (Thunb.) DC, a medicinal herb belonging to the Asteraceae family, often faces severe drought stress during its growth. Until now, there has been no research on the effect of drought stress on the quality formation of A. lancea. Therefore, the present study aimed to study the effects of drought stress on A. lancea through physical and chemical analysis, and to reveal the related molecular mechanisms via transcriptome analysis. Results The photosynthesis was markedly inhibited under drought stress. There were alterations to photosynthetic parameters (Pn, Gs, Ci) and chlorophyll fluorescence (Fv/Fm, NPQ), and the chlorophyll content decreased. Twenty genes encoding important regulatory enzymes in light and dark reactions, including the Rubisco gene of the Calvin cycle, were significantly downregulated. After exposure to drought stress for more than 4 days, the activities of four antioxidative enzymes (SOD, POD CAT and APX) began to decrease and continued to decrease with longer stress exposure. Meanwhile, most of the genes encoding antioxidative enzymes were downregulated significantly. The downregulation of 21 genes related to the respiratory electron transport chain indicated that the blocked electron transfer accelerated excessive ROS. The MDA content was significantly elevated. The above data showed that 15 days of drought stress caused serious oxidative damage to A. lancea. Drought stress not only reduced the size and dry weight of A. lancea, but also lowered the amount of total volatile oil and the content of the main bioactive components. The total volatile oil and atractylodin content decreased slightly, whereas the content of atractylon and β-eudesmol decreased significantly. Moreover, ten significantly downregulated genes encoding sesquiterpene synthase were mainly expressed in rhizomes. Conclusions After exposed to drought stress, the process of assimilation was affected by the destruction of photosynthesis; stress tolerance was impaired because of the inhibition of the antioxidative enzyme system; and bioactive component biosynthesis was hindered by the downregulation of sesquiterpene synthase-related gene expression. All these had negative impacts on the quality formation of A. lancea under drought stress.