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Reactive oxygen species (ROS) can damage lipids, nucleic acids, and proteins, thereby altering their functions. When a balance between production of ROS and antioxidative defense is disturbed, state of oxidative stress occurs. Oxidative stress leads to many diseases. There are few biomarkers that are used for better understanding how oxidative stress is involved in cancer pathophysiology. This review focuses on 8-hidroxy-2-deoxyguanosine (8-OHdG) and antioxidative enzymes as biomarkers for measurement of oxidative stress in different types of cancer. This review also deals with the product of lipid peroxidation, malondialdehyde (MDA), and across a variety of cancers. To address this aim, analysis of studies of breast, prostate, lung, colon, cervical, ovarian, brain, bladder, renal, thyroid cancer, and chronic lymphocytic leukemia has been conducted. In general, levels of antioxidative enzymes are mostly lower in cancer patients, while 8-OHdG and MDA are higher. Further research is needed, with focus on correlation levels of these biomarkers and advancement of the disease. Moreover, all studies explored the idea of those biomarkers as a useful tool in determining the levels of oxidative stress. Some of the studies proposed their potential in defining the stage of tumor progression.

Oxidative stress (OxS) is the cause and the consequence of metabolic syndrome (MetS), the incidence and economic burden of which is increasing each year. OxS triggers the dysregulation of signaling pathways associated with metabolism and epigenetics, including microRNAs, which are biomarkers of metabolic disorders. In this review, we aimed to summarize the current knowledge regarding the interplay between microRNAs and OxS in MetS and its components. We searched PubMed and Google Scholar to summarize the most relevant studies. Collected data suggested that different sources of OxS (e.g., hyperglycemia, insulin resistance (IR), hyperlipidemia, obesity, proinflammatory cytokines) change the expression of numerous microRNAs in organs involved in the regulation of glucose and lipid metabolism and endothelium. Dysregulated microRNAs either directly or indirectly affect the expression and/or activity of molecules of antioxidative signaling pathways (SIRT1, FOXOs, Keap1/Nrf2) along with effector enzymes (e.g., GPx-1, SOD1/2, HO-1), ROS producers (e.g., NOX4/5), as well as genes of numerous signaling pathways connected with inflammation, insulin sensitivity, and lipid metabolism, thus promoting the progression of metabolic imbalance. MicroRNAs appear to be important epigenetic modifiers in managing the delicate redox balance, mediating either pro- or antioxidant biological impacts. Summarizing, microRNAs may be promising therapeutic targets in ameliorating the repercussions of OxS in MetS.

Photosynthesis is a pivotal process that determines the synthesis of carbohydrates required for sustaining growth under normal or stress situation. Stress exposure reduces the photosynthetic potential owing to the excess synthesis of reactive oxygen species that disturb the proper functioning of photosynthetic apparatus. This decreased photosynthesis is associated with disturbances in carbohydrate metabolism resulting in reduced growth under stress. We evaluated the importance of melatonin in reducing heat stress-induced severity in wheat (Triticum aestivum L.) plants. The plants were subjected to 25 °C (optimum temperature) or 40 °C (heat stress) for 15 days at 6 h time duration and then developed the plants for 30 days. Heat stress led to oxidative stress with increased production of thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide (H2O2) content and reduced accrual of total soluble sugars, starch and carbohydrate metabolism enzymes which were reflected in reduced photosynthesis. Application of melatonin not only reduced oxidative stress through lowering TBARS and H2O2 content, augmenting the activity of antioxidative enzymes but also increased the photosynthesis in plant and carbohydrate metabolism that was needed to provide energy and carbon skeleton to the developing plant under stress. However, the increase in these parameters with melatonin was mediated via hydrogen sulfide (H2S), as the inhibition of H2S by hypotaurine (HT; H2S scavenger) reversed the ameliorative effect of melatonin. This suggests a crosstalk of melatonin and H2S in protecting heat stress-induced photosynthetic inhibition via regulation of carbohydrate metabolism.

Biosynthesis of copper oxide nanoparticles (CuONPs) in a cost-effective and eco-friendly way has gained its importance. CuONPs has been prepared from copper sulfate by using Adiantum lunulatum whole plant extract. CuONPs have been characterized by X-ray diffraction, Fourier transform infrared spectroscopic, transmission electron microscope, etc. Mono-disperse, spherical, pure, and highly stable CuONPs have formed with an average diameter of 6.5 ± 1.5 nm. Biosynthesized CuONPs at different concentrations were applied to seeds of Lens culinaris. Physiological characteristics were investigated in the germinated seeds. Roots obtained from the seeds treated with 0.025 mgmL−1 concentration of CuONPs showed highest activity of different defence enzymes and total phenolics. However, at higher concentration it becomes close to control. It showed gradual increase of antioxidative enzymes, in accordance with the increasing dose of CuONPs. Likewise, lipid peroxidation and proline content gradually increased with the increasing concentration. Reactive oxygen species and nitric oxide generation was also altered due to CuONPs treatment indicating stress signal transduction. Finally, this study provides a new approach of the production of valuable CuONPs, is a unique, economical, and handy tool for large scale saleable production which can also be used as a potent plant defence booster instead of other commercial uses.

Chemical fertilizers used in plant development and differentiation have become a global problem affecting the entire ecosystem, especially soil pollution. Food production demand with the increasing population has encouraged scientists to use biogenic nanoparticles in the agricultural field. Evaluation of growth, development, and differentiation processes of sweet basil (Ocimum basilicum L.) seedlings at gradually increasing concentrations of biogenic iron oxide nanoparticles (BIO-NPs) were identified by morphological and physiological parameters in this study. The results showed that growth parameters reached the maximum value at 100 mg/L but were less at other concentrations. At similar concentration, the stomatal density of the leaf was the maximum, while the stomatal area showed the lowest value. The levels of H2O2 and malondialdehyde (MDA) decreased in the treated seedlings. BIO-NPs increased the antioxidant defense and supported its growth by changing the antioxidant enzyme activities, H2O2, and MDA contents. The BIO-NP treatment provided positive improvements in phytochemical content in parallel with the growth and development of sweet basil seedlings. Different growth parameters, physiological results, supporting enzyme activities, and biochemical data revealed the contribution of the BIO-NP treatments to the growth and development of sweet basil seedlings. BIO-NPs improved higher phytochemical production of sweet basil, which may be suitable for its propagation on a commercial scale.

The liver and its zonation contribute to whole body homeostasis. Acute and chronic, not always liver, diseases impair proper metabolic zonation. Various underlying pathways, such as β-catenin, hedgehog signaling, and the Hippo pathway, along with the physiologically occurring oxygen gradient, appear to be contributors. Interestingly, hypoxia and hypoxia-inducible transcription factors can orchestrate those pathways. In the current review, we connect novel findings of liver zonation in health and disease and provide a view about the dynamic interplay between these different pathways and cell-types to drive liver zonation and systemic homeostasis.

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.

In this study, we investigated the possible role of hemin in alleviating zinc (Zn), lead (Pb) and chromium (Cr) toxicity in rice seedlings grown hydroponically by analyzing the morphological and physiological parameters. Our results showed that exposure of rice seedlings to excess Zn, Pb or Cr could cause severe leaf chlorosis, inhibit photosynthetic activity and consequently suppress plant growth. The concentration of O 2 •− and H 2 O 2 significantly increased and the activities of antioxidative enzymes decreased in roots of rice seedlings under metal exposure. The combined treatments (hemin + ZnSO 4 , hemin + Pb(NO 3 ) 2 and hemin + K 2 Cr 2 O 7 ), on the other hand, significantly enhanced the photosynthesis- and plant growth-related parameters compared with their corresponding heavy-metal-stress alone. Combined treatments dramatically stimulated the activities of superoxide dismutase (SOD), ascorbic peroxidase (APX) and glutathione reductase (GR) as well as the concentrations of ascorbic acid (AsA) and glutathione (GSH) as compared with the metal- stress alone. The concentrations of reactive oxygen species (ROS, e.g. O 2 •− and H 2 O 2 ) were significantly reduced in the metal plus hemin treatments. Hemin addition also reduced metal accumulation in rice seedlings especially in root tissues. These findings suggest that hemin-elevated levels of antioxidants, activities of antioxidative enzymes and hemin-reduced accumulation of heavy-metal could confer resistance against Zn, Pb, and Cr stress in rice seedlings, resulting in improved pigments accumulation, photosynthetic attributes and plant growth.

Background and Aims The role of L-histidine (L-His) in nickel (Ni) hyperaccumulation is not well known. The present study aimed to understand the impact of L-His on Ni translocation and Ni tolerance in Odontarrhena inflata and Aurinia saxatilis . Methods To determine the impact of L-His and L-alanine (L-Ala) on the shoot Ni accumulation, we quantified the Ni concentration in plants pretreated with amino acids for 4 h and then exposed to Ni for 8 h. Hydrogen peroxide (H 2 O 2 ) and antioxidant enzymes activities were determined after 4 h of pretreatments and 48 h of Ni treatments. Results L-histidine increased Ni translocation to shoots in O. inflata and A. saxatilis . Ni increased the activity of POD, APX, and CAT in both species, but the activities of APX and CAT were higher in O. inflata . Ni exposure increased the H 2 O 2 concentration in A. saxatilis . L-His pretreatment did not decrease the H 2 O 2 concentration in Ni-treated plants, but decreased the activity of POD, APX, and CAT only at 300 µM Ni in O. inflata . In A. saxatilis, L-His pretreatment, decreased the activity of CAT, but increased POD activity at 150 and 300 µM Ni. Pretreatment with L-Ala decreased POD and APX activity but had no significant impact on H 2 O 2 concentration and CAT activity. Conclusion L-Histidine promoted root-to-shoot Ni translocation and alleviated Ni toxicity, possibly through inducing the activities of antioxidant enzymes, in hyperaccumulator and non-accumulator plants. Histidine might not only facilitate the Ni translocation, but also contribute to Ni tolerance, at least in A. saxatlilis .

The purpose of current investigation was to explore the role of brassinosteroids (BRs) in Zea mays L. var. DKC 9106 seedlings subjected to salt stress. The seedlings were raised under controlled laboratory conditions and subjected to different concentrations of NaCl (0, 40, 60, 80, 100 mM) for 10 days. The impact of pre-sowing treatment of both 28-homobrassionolide (HBL) and 24-epibrassinolide (EBL) on defense system of Z. mays L. under salt stress was studied by analyzing Na+ and K+ ions, malondialdehyde content (MDA), antioxidative enzymes activities (peroxidase, POD; catalase, CAT; dehydroascorbate reductase, DHAR; monodehydroascorbate reductase, MDHAR), osmoprotectants (proline, glycine betaine, mannitol, and total osmolytes content), total phenolic content, total flavonoid content, and 1,1-diphenylpicrylhydrazyl (DPPH) free radical scavenging activity. The results of our finding showed that treatment of both HBL and EBL under high salt stress balanced the ionic status by decreasing the Na+ ions content by 21.23% and 38.94%, respectively, and enhancing the K+ ions content by 51.94% and 26.66%, respectively. Treatment of both BRs also overcome the oxidative damage induced due to salinity stress by reducing the MDA accumulation 19.50% and 45.0%, respectively, and enhancing the activities of antioxidative enzymes. The osmoprotectants: proline (50.08% and 17.03%), glycine betaine (35.57% and 28.16%), and mannitol content (2.80% and 20.98%) were markedly increased by the treatment of both HBL and EBL, respectively. Further, treatment of both HBL and EBL also increased the total phenolic content by 11.68% and 5.80%, total flavonoid content by 31.56 and 31.09% and DPPH free radical scavenging activity by 37.99% and 77.41%, respectively. Overall the treatment of BRs before seed sowing considerably conquer the salinity-induced damage by stimulating functional components of antioxidative defense system and ultimately reduced oxidative damage.