Higher Levels Of Lipid Peroxidation Research Articles

In Vitro Antioxidant Mechanism of Action of Hibiscus Sabdariffa in the Induction of Apoptosis against Breast Cancer

ABSTRACT The antioxidant mechanism of action in the process of cytotoxicity, and pro-apoptotic activity of Hibiscus sabdariffa water extract (HSWE) was assessed against non-cancerous (MCF12A) and breast cancer (MCF7) cells grown in DMEM-F12 and DMEM, respectively. The treated cells revealed a polyphenolic and anthocyanin content of 17.7 ± 0.4 mg g−1 and 24.8 ± 0.5 mg g,−1 respectively. The oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assay values were 1506 ± 30.1 µmoleTE g−1 and 428.9 ± 3.8 µmoleAAE g−1 at 1.0 mg mL−1, respectively, indicating a high antioxidant capacity. The HSWE induced greater apoptosis than doxorubicin (62.5 ± 2.6%), as more cytotoxic effect was noted against MCF7 with 70.4 ± 2.4% than MCF12A (15.3 ± 1.4%) cells at 0.4 mg mL−1. The HSWE depolarized mitochondrial MCF7 by 42.5 ± 0.5% compared to 4.6 ± 0.3% against MCF12A at 0.3 mg mL−1. It altered the intracellular redox status of MCF7 cells by depleting antioxidant enzymes with high levels of lipid peroxidation and reactive oxygen species [ROS] in MCF7 than in MCF12A. HSWE selectively induced apoptosis on MCF7 cells via ROS generation, lipid peroxidation, and mitochondrial dysfunction pathway.

The effect of seasonality on the phytochemical composition of two Limonium species naturally growing in a Mediterranean arid-salt marsh: Harvesting time optimization by modeling approach

Limonium species are widely considered as potential ornamental candidates for dry and saline areas in arid zones. Limonium pruinosum and Limonium tunetanum are perennial halophytic herbs occurring in extreme biotopes; they are polyphenol-rich herbal medicine with antioxidant potentials. This paper outlines the effect of seasonality on the phytochemical profile as well as the antioxidant potential of these species using a modeling approach to establish the optimum harvesting time. Accordingly, the shoots of L. pruinosum and L. tunetanum were monthly harvested over 1 year from the shott of Sebkha of Aïn Maider – Boughrara (Tunisia). Both species were affected by the seasonal fluctuation, as was evidenced by the high levels of lipid peroxidation, hydrogen peroxide, and electrolyte leakage during the dry period. The harvesting time had a significant effect on the polyphenols, flavonoids, condensed tannins, and antioxidant potentials. Generally, the shoots harvested during the dry season had significantly greater content of bioactive compounds and consequently, higher antioxidant activity, when compared to those collected during the wet period, as confirmed by the adopted exponential model. Indeed, the oxidative stress markers, the phytochemical contents, and the antioxidant capacity were highly and positively correlated with the soil sodium content and the air temperature. Moreover, 18 and 14 individual phenolic compounds were confirmed in L. pruinosum and L. tunetanum extracts, respectively, which mostly consisted of quinic acid, gallic acid, 4,5-di-O-caffeoylquinic acid, hyperoside, quercetrin, catechin, and rutin. The identified phenolic acids and flavonoid compounds were highly and differently affected by seasonality. Considering the phytochemical analysis and the established model, the dry season could be the optimal harvest time.

Mutant p53K120R expression enables a partial capacity to modulate metabolism.

The TP53 tumor suppressor gene is one of the most studied gene in virtue of its ability to prevent cancer development by regulating apoptosis, cell cycle arrest, DNA repair, autophagy and senescence. Furthermore, the modulation of metabolism by P53 is fundamental for tumor suppressor activity. Studies in mouse models showed that mice carrying TP53 mutations affecting the acetylation in the DNA binding domain still retain the ability to transactivate genes involved in metabolism. Noteworthy, mice expressing the triple 3KR or the single K117R mutant do not show early on-set tumor development in contrast to TP53 −/− mice. Interestingly, the mouse K117R mutation corresponds to the human tumor-derived K120R modification, which abrogates P53-dependent activation of apoptosis without affecting growth arrest. In this study, we investigated the property of the human P53 K120R mutant in the regulation of metabolism by analyzing the transcriptional specificity in yeast- and mammalian-based reporter assays, the metabolic phenotype associated to its expression in colon cancer HCT116 TP53−/− cells and the induction of P53 targets and proteins involved in the antioxidant response. These properties were analyzed in comparison to wild type P53 protein, the human triple mutant corresponding to mouse 3KR and the cancer hot-spot R273H mutant. We confirm the selective functionality of P53 K120R mutant, which shows a transcriptional activity on cell cycle arrest but not on apoptotic targets. Interestingly, this mutant shows a partial transactivation activity on p53 response element belonging to the metabolic target TIGAR. Moreover, we observe a significant uncoupling between oxygen consumption and ATP production associated with higher lipid peroxidation level in all P53 mutants carrying cells with respect to wild type P53 expressing cells. Noteworthy, in the absence of a pro-oxidative challenge, cells expressing K120R mutant retain a partial capacity to modulate glucose metabolism, limiting lipid peroxidation with respect to the other P53 mutants carrying cells. Lastly, especially in presence of human 3KR mutant, a high expression of proteins involved in the antioxidant response is found. However, this response does not avoid the increased lipid peroxidation, confirming that only wild type P53 is able to completely counteract the oxidative stress and relative damages.

Impact of Biochar Application at Water Shortage on Biochemical and Physiological Processes in Medicago ciliaris.

The application of biochar is mostly used to improve soil fertility, water retention capacity and nutrient uptake. The present study was conducted in order to study the impact of biochar at water deficiency conditions on the physiological and biochemical processes of Medicago ciliaris seedlings. Seedlings were cultivated under greenhouse conditions in pots filled with a mixture of soil and sand mixed in the presence or absence of 2% biochar. Plants of uniform size were subjected after a pretreatment phase (72 days) either to low (36% water holding capacity, water potential low) or high soil water potential (60% water holding capacity, water potential high). Pots were weighed every day to control and maintain a stable water holding capacity. In Medicago ciliaris, drought led to a significant reduction in plant growth and an increase in the root/shoot ratio. The growth response was accompanied by a decreased stomatal conductance and a reduction of the net CO2 assimilation rate and water use efficiency. The associated higher risk of ROS production was indicated by a high level of lipid peroxidation, high antioxidant activities and high proline accumulation. Soil amendment with biochar enhanced the growth significantly and supported the photosynthetic apparatus of Medicago ciliaris species by boosting chlorophyll content and Anet both under well and insufficient watered plants and water use efficiency in case of water shortage. This increase of water use efficiency was correlated with the biochar-mediated decrease of the MDA and proline contents in the leaves buffering the impact of drought on photosynthetic apparatus by increasing the activity of enzymatic antioxidants SOD, APX, GPOX and GR and non-enzymatic antioxidants, such as AsA and DHAsA, giving the overall picture of a moderate stress response. These results confirmed the hypothesis that biochar application significantly reduces both the degree of stress and the negative impact of oxidative stress on Medicago ciliaris plants. These results implied that this species could be suitable as a cash pasture plant in the development of agriculture on dry wasteland in a future world of water shortages.

Spatio-temporal changes in oxidative stress physiology parameters in apple snail Pila globosa as a function of soil Mg, Ca, organic carbon and aquatic physico-chemical factors.

Information on the oxidative stress physiology parameters (OSPP) in general and as a function of the fluctuation of Mg, Ca and organic carbon present in soil and aquatic physico-chemical factors such as pH, temperature and salinity in particular are scanty in the amphibious snail Pila globosa. A spatio-temporal analysis of redox metabolism (as OSPP) followed by discriminant function analysis of the obtained data were performed in P. globosa sampled from the east-coasts of Odisha state, India (mostly along the Bay of Bengal) for environmental health assessment purposes. Results revealed that the OSPP are susceptible to seasonal synergistic variation of soil and physico-chemical factors. Overall, lipid peroxidation, total antioxidant capacity, activities of catalase, glutathione reductase had positive correlation whereas ascorbic acid, the reduced glutathione and the activity of superoxide dismutase had non-significant correlation with the soil Mg, Ca, organic carbon, and pH, temperature and salinity of water. In the summer season, the snails had a marked 51.83% and 26.41% higher lipid peroxidation level and total antioxidative activity as compared to the other seasons. Spatial variation of OSPP indicates that snails residing away from the Bay of Bengal coast had at least 4.4% lower antioxidant level in winter and 30% higher lipid peroxide levels in summer as compared to the rest of the sampling sites. Results on OSPP in P. globosa may be useful for monitoring the ecotoxic effects of environment using molluscs in general and P. globosa in particular.

Specific and combined effects of dietary ethanol and arginine on Drosophila melanogaster

In this study, we have investigated specific and combined effects of essential amino acid, l-arginine, and ethanol (EtOH), a natural component of Drosophila melanogaster food, on a range of physiological and biochemical parameters of the flies. Rearing of D. melanogaster during two weeks on the food supplemented with 50 mM l-arginine decreased activities of catalase, glucose-6-phosphate dehydrogenase, and glutathione-S-transferase in males by about 28%, 60%, and 60%, respectively. At the same time, arginine-fed males had 40% higher levels of lipid peroxides and arginine-fed females had 36% low-molecular mass thiol levels as compared to the control. Arginine decreased resistance of fruit flies to heat stress in both sexes, resistance to starvation in females, and resistance to sodium nitroprusside (SNP) in males. Nevertheless, arginine increased resistance to SNP in females. Consumption of food supplemented with 10% EtOH increased resistance of fruit flies to starvation but made them more sensitive to SNP. On the contrary, arginine abrogated the ability of EtOH to increase starvation resistance in males and to decrease SNP resistance in both sexes.

Toxicity Mitigation of Textile Dye Reactive Blue 4 by Hairy Roots of Helianthus annuus and Testing Its Effect in In Vivo Model Systems.

An anthraquinone textile dye, Reactive Blue 4 (RB4), poses environmental health hazards. In this study, remediation of RB4 (30-110 ppm) was carried out by hairy roots (HRs). UV-visible spectroscopy and FTIR analysis showed that the dye undergoes decolourization followed by degradation. In addition, toxicity and safety analyses of the bioremediated dye were performed on Allium cepa and zebrafish embryos, which revealed lesser toxicity of the bioremediated dye as compared to untreated dye. For Allium cepa, the highest concentration, i.e., 110 ppm of the treated dye, showed less chromosomal aberrations with a mitotic index of 8.5 ± 0.5, closer to control. Two-fold decrease in mortality of zebrafish embryos was observed at the highest treated dye concentration indicating toxicity mitigation. A higher level of lipid peroxidation (LPO) was recorded in the zebrafish embryo when exposed to untreated dye, suggesting a possible role of oxidative stress-inducing mortality of embryos. Further, the level of LPO was significantly normalized along with the other antioxidant enzymes in embryos after dye bioremediation. At lower concentrations, mitigated samples displayed similar antioxidant activity comparable to control underlining the fact that the dye at lesser concentration can be more easily degraded than the dye at higher concentration.

Stress response of the coral Stylophora pistillata towards possible anthropogenic impacts in the Gulf of Aqaba, Red Sea

Coral deterioration is often linked with coastal pollution. This aimed to study biochemical stress responses in the common coral Stylophora pistillata collected and/or planted in coastal sites subject to pollution and sites without pollution in the Gulf of Aqaba. DNA damage and lipid peroxidation were analyzed to measure stress in corals. High DNA damage was found in natural corals from polluted sites, while higher lipid peroxidation was found in control site compared with polluted sites. Lipid peroxidation was higher in polluted sites after one-year of deployment. Corals’ incubations with copper and lead produced high levels of DNA damage and lipid peroxidation compared with control samples. The results suggested that although corals are visually looking healthy, but they are suffering at subcellular levels. The consequences of such stress might affect the fecundity and growth rates of corals. The results suggest that biomarkers used are efficient tools for early stress detection in corals, though the cost of assessing DNA damage is relatively expensive compared with lipid peroxidation.

Micro-contaminant, but immense impact: Source and influence of diethyl phthalate plasticizer on bottom-dwelling fishes

Sustainable plastic-waste management is becoming increasingly challenging as enormous loads of plastic debris regularly accumulate in susceptible ecosystems. The microplastic (MP) particles generated from these plastic wastes are imposing additional threats to these ecosystems due to their small size as well as their ability to adsorb and carry toxic chemicals. The current investigation deals with one such MP-originated toxicant, diethyl phthalate (DEP), and its impact on two species of freshwater loaches from the Western Ghats of India, Lepidocephalichthys thermalis and Indoreonectes evezardi. The MP samples were collected from the sediments of the Mula River and characterized using spectroscopic methods and scanning electron microscopy. Polymers, such as polyvinyl chloride and polypropylene, were identified in the collected MPs. GC-MS analysis of the MP extracts revealed the presence of DEP, confirming the MP waste as a potential source of DEP pollution. Further, to evaluate the effect of DEP on survival of selected loaches, L. thermalis and I. evezardi were exposed to DEP concentrations (18.75–300 mg L−1) and the lethal DEP dose (LC50) was estimated to be 44.53 mg L−1 for L. thermalis and 34.64 mg L−1 for I. evezardi. Fishes were further exposed to sub-lethal DEP concentration for one day (Short term exposure: STE) or eight days (Long term exposure: LTE) to analyze the histological condition and oxidative status of the liver in response to DEP treatment. Histology revealed congestion of sinusoids and vacuolization after the LTE. Higher lipid peroxidation levels were also measured in the livers of both species treated with DEP, which indicated DEP-mediated oxidative damage. The antioxidant enzymes including superoxide dismutase, catalase, peroxidase and glutathione-S-transferase displayed elevated activities in response to STE and LTE of DEP. Collectively, the results demonstrate that MPs in the Mula River are a potential source of DEP. The findings also show that DEP exposure can be fatal to freshwater fishes such as loaches, possibly by causing increased oxidative damage to the hepatic system.

Abstract 2176: NADPH production and redox homeostasis regulate acinar to ductal metaplasia

Abstract Activating mutations in KRAS reprogram cellular metabolism to support continuous growth, proliferation, and survival in pancreatic cancer. However, there is little information on how KRAS-dependent alterations in metabolism change precancerous states and cancer initiation. Acinar cells can give rise to pancreatic tumors through acinar-to-ductal metaplasia (ADM), a reversible cell state that persists and progresses to neoplasia and cancer with oncogenic KRAS. During ADM, acinar cells transdifferentiate to duct-like cells, a process we hypothesized was mediated by metabolic rewiring. We performed transcriptomic analysis on acinar cells undergoing ADM and found metabolic programs are globally enhanced. Indeed, we and others have demonstrated how inhibiting metabolic pathways necessary for ADM can prevent transdifferentiation and tumorigenesis. A detailed analysis of our data revealed that the transcripts for NADPH-producing enzymes, Glucose-6-phosphate dehydrogenase (G6pd) and Malic enzyme 1 (Me1), were significant enriched during ADM. Following these results, we obtained G6pd-mutant mice and generated Me1flox/flox mice and bred them into the KC (KrasLSL-G12D/+;Ptf1aCre/+) line, resulting in KCG (KrasLSL-G12D/+;Ptf1aCre/+;G6pdmut/mut) and KCM (KrasLSL-G12D/+;Ptf1aCre/+;Me1flox/flox) mice. Interestingly, KCG and KCM mice develop ADM and neoplasia faster than their KC counterparts. We also observe that acinar cells and ADM in KCG cells have higher levels of lipid peroxidation and reactive oxygen species (ROS) both in vivo and using primary ex vivo acinar cell cultures. Thus, increased ROS levels may underlie ADM acceleration in this system. In primary acinar cell culture, we can rescue the accelerated ADM phenotype in KCG cells with the addition of antioxidants. Furthermore, we find that treatment of wild type acinar cells with buthionine sulphoximine (BSO) to deplete glutathione levels and increase ROS also accelerates ADM in culture. These results suggest that NADPH and glutathione pools are important for regulating redox levels during ADM, and that reducing these pools leads to accelerated tumorigenesis. Together, this work demonstrates new metabolic pathways driving pancreatic cancer initiation. Citation Format: Megan D. Radyk, Barbara S. Nelson, Christopher J. Halbrook, Mengrou Shan, Jonathan Alektiar, Howard C. Crawford, Yatrik M. Shah, Costas A. Lyssiotis. NADPH production and redox homeostasis regulate acinar to ductal metaplasia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2176.

High-Risk HPV with Multiple Infections Promotes CYP2E1, Lipoperoxidation and Pro-Inflammatory Cytokines in Semen of Asymptomatic Infertile Men

High-risk human papillomavirus (HR-HPV) infection, followed by chronic inflammation and oxidative stress, is a major risk factor of male infertility. In this study, we explored the potential impact of high-risk (HR) HPV genotypes in single infection (SI) and multiple infections (MI) that promote CYP2E1 expression, oxidative damage and pro-inflammatory cytokines, possibly contributing to sperm damage and male infertility. Semen samples from 101 infertile military men were studied. We analyzed seminal parameters, namely, HPV genotyping, cytochrome P450 2E1 (CYP2E1), oxidative stress biomarkers (total antioxidant capacity (TAC), catalase (CAT) and superoxide dismutase (SOD)), lipid peroxidation (LPO), 8-hydroxiguanosine (8-OHdG) and pro-inflammatory cytokines (IFN-γ, IL-1β, IL-4, IL-6 and IL-8). Eighty-one men (80.2%, 81/101) were positive for HPV infection, and MI-HR-HPV was higher than SI-HR-HPV (63% vs. 37%). HPV-52 was the most frequently detected type (18.5%), followed by HPV-33 (11.1%), and the most frequent combination of genotypes detected was HPV-33,52 (11.1%), followed by HPV-18,31 (6.2%). The group with infected samples presented lower normal morphology and antioxidant levels compared to non-infected samples. In concordance, the infected group showed high levels of LPO, IFN-γ, IL-1β, IL-4 and IL-6 and downregulation of CAT and SOD enzymes. Interestingly, changes in motility B, low levels of TAC, overexpression of CYP2E1, LPO and IL-8 levels were higher in MI-HR-HPV than SI-HR-HPV, suggesting that HPV infection promotes a chronic inflammatory process and a toxic and oxidative microenvironment, which increases with MI-HPV infections.

Exogenous arginine treatment additively enhances growth and tolerance of Salicornia europaea seedlings under salinity

The effects of foliar application of 5 mM arginine (Arg) on the growth and control of salinity-induced osmotic and oxidative stresses (0, 200, 400 and 600 mM NaCl) in Salicornia europaea seedlings were investigated. Despite higher levels of lipid peroxidation, lower membrane stability index (MSI), decreased pigment content and phenolic compounds, and reduced activity of antioxidant enzymes observed under salinity, seedling growth indices, including plant height and biomass, increased significantly, and some protective and antioxidant molecules such as proline and flavonoids accumulated. Soluble protein level increased at the low salt concentration (200 mM) but decreased at other doses. Exogenous Arg treatment alone had less or no effect on plant biomass and other metabolites, but in combination with salt, further enhanced growth parameters, MSI and accumulation of soluble protein, phenolic compounds and proline. Arg-induced changes under salinity were associated with decreased lipid peroxidation, flavonoids content and antioxidant enzymes activity. These results show that S. europaea seedlings are well tolerant to applied salt doses. The treatment with exogenous Arg alone affects plant growth slightly, but in combination with salt, synergistically increases growth and salt tolerance of these plants by enhancing the accumulation of proline and antioxidant molecules instead of enzymatic antioxidant.

Clinical implications of lipid peroxides levels in plasma and tumor tissue in breast cancer patients

Oxidative stress can promote the oxidation of lipoproteins and polyunsaturated fatty acids present in cell membranes; an event known as lipid peroxidation (LPO). LPO has been associated with carcinogenesis and cancer progression, however, its meaning concerning the clinicopathological aspects of human breast cancer is not clear. This study investigated LPO profiles in tumor and plasma samples from breast cancer patients (n = 140) considering their clinicopathological features (age at diagnosis, menopausal status, body mass index, tumor histological grade, tumor size, ki-67 proliferation index, presence of metastasis, chemotherapy response, the molecular subtype of cancer and overall survival status). LPO levels were estimated by tert-butyl hydroperoxide-initiated chemiluminescence. High LPO levels were found regarding poor prognosis parameters as young age at diagnosis (p = 0.006 in tissue), premenopausal patients (p = 0.012 in tissue), high-grade tumors (p = 0.010 in tissue and p = 0.002 in plasma), metastatic disease (p = 0.046 in tissue), chemoresistant tumors (p = 0.041 in tissue), disease relapse (p = 0.018 in tissue and p = 0.009 in plasma) and overall survival status (p = 0.001 in plasma). Our findings point out the clinical meaning of LPO and highlight it as an oxidative stress event linked to poor prognosis and disease aggressiveness in breast cancer patients.

Comparative study on the oxidative stress of commercially important fish species from localities with different ecological conditions along the Bulgarian Black Sea coast

The aim of the present study was to perform a pilot assessment and analysis of the oxidative stress (OS) level in four commercially important fish species (round goby, red mullet, sprat and horse mackerel) from different localities of the Bulgarian Black Sea coast. The fish were sampled during trawl selectivity experiments. The OS level in the fish was assessed by measuring lipid peroxidation (LPO), glutathione concentration (GSH), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), as well as acetylcholine esterase (AChE) in gills and liver. Round goby and red mullet caught in the Nessebar Bay showed clear signs of OS with the highest levels of LPO and GST activities, accompanied by the lowest AChE activities in both liver and gills. On the contrary, round goby caught near Maslen Nos (a region with good ecological conditions) were least affected by OS with low LPO and high GSH concentrations and SOD activity. There were no significant differences in the OS bioindicators of horse mackerel from the different localities. Sprat caught in Nessebar Bay, compared to those caught from the other localities, showed presence of OS indicated by lower GSH levels and relatively higher CAT, GPx and GST activities, accompanied by low AChE activity in gills. It can be concluded that round goby and red mullet were more vulnerable to OS induced by marine environmental factors than the horse mackerel and sprat. However, their antioxidant defense system allows them to tolerate and adapt to the environment of their habitats. Further studies are needed for the assessment of OS in important fish species in the Bulgarian part of the Black Sea.

American oysters as bioindicators of emerging organic contaminants in Florida, United States

Per- and polyfluoroalkyl substances (PFAS) and phthalate esters (PAEs) are emerging contaminants of higher concern due to their wide industrial and commercial use, toxicity, and potential adverse health effects. In this study, we assessed PFAS and PAEs exposure in American oysters collected in three study sites in Florida, USA. Potential physiological effects of these contaminants were assessed by collecting oyster biometric data, calculating condition indices, and assessing oxidative stress levels in these individuals. Finally, a human health risk assessment was conducted based on the concentrations found in the consumable Tampa Bay (TB) oysters. All PFAS and PAEs compounds assessed in this study were detected in at least one oyster in all study sites. Among all locations, ΣPFAS concentration range was 0.611–134.78 ng·g−1 and ΣPAEs <0.328–1021 ng·g−1. Despite the smaller size of Biscayne Bay (BB) oysters, they displayed the highest concentrations of most of the PFAS and PAEs compounds, which is likely associated with population size, and other sources in the area. Condition index (CI) III was smaller in BB oysters, likely indicating a stressed population. Even though BB oysters were the most affected individuals, Marco Island (MI) oysters displayed the highest levels of lipid peroxidation, which can also be associated with environmental factors and decreased food availability. Conversely, TB oysters exhibited the highest levels of hydrogen peroxide, likely indicating a better defense mechanism in TB oysters compared to MI oysters. The human health risk assessment for TB oysters indicated low risk from PFAS and PAEs exposure, but there is no reference dose for other compounds and the human diet is wider than only oysters. Therefore, the risk of contaminant exposure is likely higher. This study demonstrates the value of integrating data on contaminant exposure and physiological responses of bioindicator specimens to better understand how emerging contaminants are affecting marine wildlife.

Association of heavy metals and trace elements in renal cell carcinoma: A case-controlled study.

Trace elements and/or heavy metals are important for various biological activities. However, excess amount of these elements is associated with a variety of diseases, including cancer. We aimed to analyse the alterations of trace elements levels in renal cell carcinoma (RCC) patients. In this observational study, patients with biopsy proven RCC were taken as study group while age- and sex-matched healthy volunteers were taken as control. Blood and urine samples were compared for Arsenic (As), Copper (Cu), Manganese (Mn), Selenium (Se), Cadmium (Cd), Lead (Pb) and Mercury (Hg) levels measured by inductively coupled plasma mass-spectroscopy. Serum glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) antioxidant enzymes and lipid peroxidation (LPO) levels were assessed to know the redox status between 2 groups. A total of 76 RCC cases and 64 controls were recruited in the study. A significantly higher concentration of As, Cu, Mn, Cd, Pb and Hg were observed in the blood of RCC patients as compared to controls. However, blood Se level was significantly lower in RCC patients. In 33 (43.4%) patients, one or more heavy metals were higher in the blood above their permitted level as compared to 10 (15.6%) subjects in control group. RCC patients had a higher urinary Mn and Se levels compared to controls. A significantly lower GSH-Px (182.08 ± 132.91 vs. 236.95 ± 132.94, P = 0.04) and a higher LPO levels (26.02 ± 20.79 vs. 14.06 ± 8.44, P = 0.003) were noted in RCC patients than controls. SOD levels were comparable between two groups. A significantly altered heavy metals concentration is noted in the blood and urine in RCC patients as compared to healthy controls. An associated lower levels of GSH-Px antioxidant enzyme and increased LPO in RCC patients signifies an imbalance in the redox status.

Activities of Antioxidant Enzymes in Six Rice (Oryza sativa L.) Varieties at Seedling Stage under Increasing Salinity Stress

Present study deals with the activities of antioxidant enzymes in six rice (Oryza sativa L.) varieties, namely Sadamota, Patnai, Dhoodeshwar, Ghewas, Gontrabidan-2 and Malabati, which were subjected to increasing salinity stress (0.05 M, 0.1 M and 0.15 M NaCl) from germination to seedling stage along with control under laboratory conditions. The main objective of this study was to find out variations in the activities of antioxidant enzymes which can differentiate tolerance to salinity. Increasing salinity stress induced gradual increase in the activity of Superoxide dismutase (SOD), Peroxidase, Catalse (CAT), Glutathione reductase (GR), and Ascorbate peroxidase (APX). High activities of SOD, CAT, GR and APX were observed in Doodeshwar and Malabti under salinity stress. High levels of antioxidant enzymes (SOD, CAT, APX and GR) under salinity stress will contribute to salinity tolerance in rice varieties Doodeshwar and Malabathi. Significant genotype×salt treatment interaction suggested the differential effect of stress on genotype for antioxidant enzymes. Catalse activity showed significant (p&lt;.001) positive correlation with SOD (r=.818), GR (r=.624), and APX (r=.593). High levels of Lipid peroxidation was noticed in Ghewas, Gonrabidan-2 and Sadamota, indicating higher membrane damage when compare to Doodeshwar and Malabathi under salt stress. Doodeshwar and Malabathi can be recommended as salt tolerant varieties for advance evaluation at field level. Analysis of antioxidant enzymes from rice seedlings exposed to salinity stress will provide rapid screening method and time saving. Mass screening will be conducted for preliminary selections which can be used in field conditions.

Dehydration induced hypoxia and its role on mitochondrial respiratory enzymes and oxidative stress responses in liver of Asian stinging catfish Heteropneustes fossilis

In the present study, Water Deprived Condition (WPC, up to 18 h) induced hypoxia and altered oxidative stress (OS) physiology along with responses of respiratory chain enzyme in Heteropneustes fossilis are described . The body O2 saturation level in the fish was declined with respect to air exposure. Higher levels of lipid peroxidation and protein carbonylation were recorded in the tissue of fish exposed to 6 h of WPC stress. The regulation of the mitochondrial complex and antioxidant enzymes, small antioxidant molecules indicated that the fish can moderately survive up to 6 h of air exposure. Probably with the onset of metabolic depression, it can critically resist the dehydration stress up to 18 h. Although the activities of glutathione peroxidase and reductase were elevated, activities of antioxidant enzymes such as superoxide dismutase and catalase were insufficient to combat WPC induced ROS and OS generated under hypoxia. The small antioxidant molecules played a key role in elimination of ROS. The elevated complex II activity was probably responsible for resisting the complex I, II and IV mediated electron leakage events in mitochondria of the fish under WPC. The total H2O2 removing capacity was less under WPC while the total units of all calculated antioxidants were alleviated signifying an interesting mechanism of WPC induced OS in the fish.

Peroxiredoxin 6 Peroxidase and Ca2+-Independent Phospholipase A2 Activities Are Essential to Support Male-Mouse Fertility.

Human infertility is an important health problem that affects one in six couples worldwide. Half of these cases are due to male infertility. Oxidative stress is a common culprit of male infertility, promoting lipid peroxidation and the oxidation of proteins and DNA in spermatozoa, thereby impairing motility, capacitation and fertilization. Peroxiredoxin 6 (PRDX6) possesses peroxidase and Ca2+-independent-phospholipase-A2 (iPLA2) activities that scavenge ROS and repair oxidized sperm membranes, respectively. PRDX6 protects spermatozoa against oxidative stress. Infertile men’s spermatozoa have impaired motility, elevated lipid peroxidation levels and DNA damage due to low PRDX6 levels. A lack of PRDX6 is associated with male-mouse infertility. Here, we determined the impact of the absence of PRDX6 peroxidase or iPLA2 activities on male-mouse fertility. Two-month-old male C57Bl6/J (wild-type), Prdx6−/−, C47S and D140A knock-in (peroxidase- and iPLA2-deficient, respectively) male mice were challenged with an in vivo oxidative stress triggered by tert-butyl hydroperoxide (t-BHP). C47S and D140A males produced smaller litters compared to wild-type controls. The t-BHP treatment promoted a lower number of pups, high levels of lipid peroxidation, tyrosine nitration, and DNA oxidation in all mutant spermatozoa compared to wild-type controls. All mutant spermatozoa had impaired capacitation and motility. In summary, both PRDX6 peroxidase and iPLA2 activities are essential to support male-mouse fertility.

Metal biomonitoring using fractioned dust to investigate urinary and oxidative stress biomarkers among occupationally exposed chromite mine workers.

Exposure to heavy metals has been associated with the generation of reactive oxygen species (ROS) among exposed individuals in occupational and environmental settings. Dust is considered a significant contributor to airborne metal exposure, and previous data suggest that their levels in dust may vary based on its particle sizes. However, no biomonitoring study has been reported so far to address the metal-induced oxidative stress using different dust fractions, particularly in occupational settings. We designed a systematic cross-sectional study involving 110 chromite mine workers stratified into loaders (n = 28), extractors (n = 47) and operators (n = 35), and controls (n = 30) to find out the association between dust-bound metal exposure and oxidative stress using urinary creatinine-adjusted metal level as a biomarker of metal exposure. Results suggested elevated urinary levels of Cr 51.34 ± 8.6 along with Pb 34.29 ± 4.39, Cd 21.1 ± 2.6, and Ni 18.98 ± 3.01µg/g creatinine in exposed (extractor group) workers. Correlating metal levels with oxidative stress revealed elevated malondialdehyde (MDA) levels of 62.28 ± 5.52nM/dl among the extractors showing high levels of lipid peroxidation. Furthermore, blood superoxide dismutase (SOD) was also found significantly correlated (P = 0.000) with urinary toxic metal levels among exposed workers. We report the association between metal exposure and oxidative stress in exposed mining workers that may give rise to workers' susceptibility towards genetic and non-genetic health implications. The current study emphasized on the need for exposure control measures in the chromite ore mining activity areas.