Levels Of Oxidative DNA Damage Research Articles

Dapagliflozin suppresses diabetes-induced oxidative DNA damage and hypermethylation in mouse somatic cells

Diabetes mellitus is a complex metabolic disorder resulting from the interplay of environmental, genetic, and epigenetic factors that increase the risk of cancer development. However, it is unclear whether the increased cancer risk is due to poor glycemic control or the use of some antidiabetic medications. Therefore, we investigated the genetic and epigenetic changes in somatic cells in a mouse model of diabetes and studied whether multiple exposures to the antidiabetic medication dapagliflozin influence these changes. We also elucidated the mechanism(s) of these ameliorations. The micronucleus test and modified comet assay were used to investigate bone marrow DNA damage and methylation changes. These assays revealed that dapagliflozin is non-genotoxic in the tested regimen, and oxidative DNA damage and hypermethylation were significantly higher in diabetic mice. Spectrophotometry also evaluated oxidative DNA damage and global DNA methylation, revealing similar significant alterations induced by diabetes. Conversely, the dapagliflozin-treated diabetic animals significantly reduced these changes. The expression of some genes involved in DNA repair and DNA methylation was disrupted considerably in the somatic cells of diabetic animals. In contrast, dapagliflozin treatment significantly restored these disruptions and enhanced DNA repair. The simultaneous effects of decreased oxidative DNA damage and hypermethylation levels suggest that dapagliflozin can be used as a safe antidiabetic drug to reduce DNA damage and hypermethylation in diabetes, demonstrating its usefulness in patients with diabetes to control hyperglycemia and decrease the development of its subsequent complications.

Are bioplastics safe? Hazardous effects of polylactic acid (PLA) nanoplastics in Drosophila

The expanded uses of bioplastics require understanding the potential health risks associated with their exposure. To address this issue, Drosophila melanogaster as a versatile terrestrial in vivo model was employed, and polylactic acid nanoplastics (PLA-NPLs), as a proxy for bioplastics, were tested as a material model. Effects were determined in larvae exposed for 4 days to different concentrations (25, 100, and 400 μg/mL) of 463.9 ± 129.4 nm PLA-NPLs. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) approaches permitted the detection of PLA-NPLs in the midgut lumen of Drosophila larvae, interacting with symbiotic bacteria. Enzymatic vacuoles were observed as carriers, collecting PLA-NPLs and enabling the crossing of the peritrophic membrane, finally internalizing into enterocytes. Although no toxic effects were observed in egg-to-adult survival, cell uptake of PLA-NPLs causes cytological disturbances and the formation of large vacuoles. The translocation across the intestinal barrier was demonstrated by their presence in the hemolymph. PLA-NPL exposure triggered intestinal damage, oxidative stress, DNA damage, and inflammation responses, as evaluated via a wide set of marker genes. Collectively, these structural and molecular interferences caused by PLA-NPLs generated high levels of oxidative stress and DNA damage in the hemocytes of Drosophila larvae. The observed effects point out the need for further studies aiming to deepen the health risks of bioplastics before adopting their uses as a safe plastic alternative.

Oxidation of DNA and RNA in young patients with newly diagnosed bipolar disorder and relatives

Excessive oxidative stress-generated nucleoside damage seems to play a key role in bipolar disorder (BD) and may present a trait phenomenon associated with familial risk and is one of the putative mechanisms explaining accelerated atherosclerosis and premature cardiovascular diseases (CVD) in younger patients with BD. However, oxidative stress-generated nucleoside damage has not been studied in young BD patients and their unaffected relatives (UR). Therefore, we compared oxidative stress-generated damage to DNA and RNA in young patients newly diagnosed with BD, UR, and healthy control individuals (HC). Systemic oxidative stress-generated DNA and RNA damage levels were compared by analyzing urinary levels of 8-oxo-7,8-dihydro-2′-deoxyguanosine and 8-oxo-7,8-dihydroguanosine in participants aged 15–25 years, including 133 patients newly diagnosed with BD, 57 UR, and 83 HC. Compared with HC, damage to DNA was 21.8% higher in BD patients (B = 1.218, 95% CI = 1.111–1.335, p = <0.001) and 22.5% higher in UR (B = 1.225, 95% CI = 1.090–1.377, p = <0.002), while damage to RNA was 14.8% higher in BD patients (B = 1.148, 95% CI = 1.082–1.219, p = <0.001) and 14.0% higher in UR (B = 1.140, 95% CI = 1.055–1.230, p = < 0.001) in models adjusted for sex and age after correction for multiple comparison. Levels did not differ between patients with BD and UR. Our findings support higher oxidative stress-generated nucleoside damage being a trait phenomenon in BD associated with familial risk and highlight the importance of early diagnosis and treatment to prevent illness progression and development of premature CVD.

Dose-dependent exposure to indoxyl sulfate alters AHR signaling, sirtuins gene expression, oxidative DNA damage, and bone mineral status in rats

Indoxyl sulfate (IS), an agonist of aryl hydrocarbon receptors (AhR), can accumulate in patients with chronic kidney disease, but its direct effect on bone is not clear. The present study investigated the effect of chronic exposure to low (100 mg/kg b.w.; 100 IS) and high (200 mg/kg b.w.; 200 IS) dose of IS on bone AhR pathway, sirtuins (SIRTs) expression, oxidative DNA damage and bone mineral status in Wistar rats. The accumulation of IS was observed only in trabecular bone tissue in both doses. The differences were observed in the bone parameters, depending on the applied IS dose. The exposure to 100 IS increased AhR repressor (AhRR)-CYP1A2 gene expression, which was associated with SIRT-1, SIRT-3 and SIRT-7 expression. At the low dose group, the oxidative DNA damage marker was unchanged in the bone samples, and it was inversely related to the abovementioned SIRTs expression. In contrast, the exposure to 200 IS reduced the expression of AhRR, CYP1A, SIRT-3 and SIRT-7 genes compared to 100 IS. The level of oxidative DNA damage was higher in trabecular bone in 200 IS group. Femoral bone mineral density was decreased, and inverse relations were noticed between the level of trabecular oxidative DNA damage and parameters of bone mineral status. In conclusion, IS modulates AhR-depending signaling affecting SIRTs expression, oxidative DNA damage and bone mineral status in a dose dependent manner.

Genoprotective role of pembrolizumab liposome in isolated lymphocytes from head and neck squamous cell carcinoma patients compared to those from healthy individuals in vitro

Pembrolizumab has shown significant anticancer effects against various human cancers. The present study investigated the effects of pembrolizumab liposome and nano (naked) forms in treated lymphocytes from head and neck squamous cell carcinoma (HNSCC) patients compared to healthy individuals. The level of oxidative DNA damage induced by hydrogen peroxide (H2O2) was also investigated. A concentration of 10 µg/ml of pembrolizumab liposome was used to treat the lymphocytes in the Comet and micronucleus assays based on the preliminary dosage optimization tests. To determine the cellular pathways involved in the protective role of pembrolizumab against H2O2, several proteins involved in apoptosis (P53, P21 and Bcl-2) were assessed. Pembrolizumab significantly reduced DNA damage and decreased the number of micronuclei in lymphocytes from HNSCC patients (p < 0.01) compared with healthy individuals. The 10 µg/ml of pembrolizumab liposome significantly reduced the oxidative stress induced by H2O2 and was effective in healthy and HNSCC groups using the Comet and micronucleus assays (p < 0.001). To our knowledge, this is the first report of pembrolizumab in liposome and naked forms exhibiting a protective effect on DNA damage in the treatment of HNSCC patients.

Piperlongumine mediates amelioration of osteoarthritis via inhibition of chondrocyte senescence and inflammation in a goat ex vivo model

In osteoarthritis (OA), chondrocytes manifest senescence, which results in a vicious signaling loop that aids the progression of the disease. More specifically, inflammation-associated senescence is one of the major regulators of the initiation and progression of OA. Therefore, we targeted senescence through inflammation with a pharmacological approach for OA amelioration. In this study, we first confirmed the suitability of the IL1β-induced goat ex vivo OA model (emphasizing 3R's principle) for the screening of senotherapeutics, namely, ABT-263, ABT-737, and Piperlongumine (PL), wherein PL showed a positive outcome in the preliminary studies. Thereafter, we determined the cytocompatible concentrations of PL using live/dead staining. Further, treatment of ex vivo OA cartilage with PL exhibited a concentration-dependent increase in the retention of key cartilage matrix components. We then examined the effect of PL on chondrocyte senescence and observed a decreased expression of major senescence markers in the PL-treated groups. Interestingly, PL treatment reduced the expression of major downstream effectors of the chondrocyte senescence pathway in a concentration-dependent manner at both gene and protein levels. Moreover, IL1β-induced elevated levels of oxidative stress and DNA damage in cartilage explants were rescued by all the tested concentrations of PL. In addition, PL also reduced the expression of major inflammatory markers of OA in the goat ex vivo OA model. Finally, we proposed a model for the mechanism of action of PL in the treatment of OA. Overall, PL showed a promising outcome as a senotherapeutic for the amelioration of OA in the goat ex vivo OA model.

Differential Modulation of Markers of Oxidative Stress and DNA Damage in Arterial Hypertension.

Patients with arterial hypertension have an increased risk of developing tumors, particularly renal cell carcinoma. Arterial hypertension is linked to DNA damage via the generation of oxidative stress, in which an upregulated renin-angiotensin-aldosterone system plays a crucial role. The current study investigated surrogates of oxidative stress and DNA damage in a group of hypertensive patients (HypAll, n = 64) and subgroups of well (HypWell, n = 36) and poorly (HypPoor, n = 28) controlled hypertensive patients compared to healthy controls (n = 8). In addition, a longitudinal analysis was performed with some of the hypertensive patients. Markers for oxidative stress in plasma (SHp, D-ROM, and 3-nitrotyrosine) and urine (8-oxodG, 15-F2t-isoprostane, and malondialdehyde) and markers for DNA damage in lymphocytes (γ-H2AX and micronuclei) were measured. In HypAll, all markers of oxidative stress except malondialdehyde were increased compared to the controls. After adjustment for age, this association was maintained for the protein stress markers SHp and 3-nitrotyrosine. With regard to the markers for DNA damage, there was no difference between HypAll and the controls. Further, no significant differences became apparent in the levels of both oxidative stress and DNA damage between HypWell and HypPoor. Finally, a positive correlation between the development of blood pressure and oxidative stress was observed in the longitudinal study based on the changes in D-ROM and systolic blood pressure. In conclusion, we found increased oxidative stress in extensively treated hypertensive patients correlating with the level of blood-pressure control but no association with DNA damage.

Effect of Barley Grass on Antioxidant Capacity and DNA Damage in Diabetic Rats

Objective: Worldwide, phytotherapy methods acquire great importance, and studies in this field are increasing their importance each day. This study, it was aimed to examine total antioxidant, oxidant status, oxidative DNA damage, glucose and hemoglobin A1c levels and the effects of barley grass juice on these parameters in rats with diabetes mellitus.&#x0D; Material and Method: Four groups were formed for the study and 6 male rats weighing 250-350 g were used in each group. Control Group; physiological saline was injected via intraperitoneal., Diabetic Group; created using streptozotocin, Barley Grass Group; Barley grass juice (3 ml/rat/day) was given orally for 4 weeks, Diabetic and Barley Grass Group; was injected streptozotocin and barley grass juice was given by oral for 4 weeks.&#x0D; Results: It was determined that barley grass juice decreased blood sugar, glucose, hemoglobin A1c, total oxidative status and oxidative stress index values, increased total anti-oxidative status value, and body weights in streptozotocin-induced diabetes. In addition, it was determined that the addition of barley grass juice provided a significant protective effect and improvement in these parameters.&#x0D; Conclusion: Based on these findings, we can say that barley grass juice has an antidiabetic-antioxidant effect and weight gain in diabetes mellitus

High urinary oxidative DNA damage in wild chimpanzees ranging in proximity of agricultural fields in Sebitoli area, Uganda.

Agriculture expansion is a major cause of habitat loss and exposure to phytochemical pollution for non-human primates. In addition to endocrine disruption, exposure to pesticides may have other sublethal physiological consequences for animals, such as generation of oxidative damage to macromolecules. In this study, we analyzed the pesticides contained in the river water across the home range of wild chimpanzees (Pan troglodytes) in Sebitoli area located on the Northern part of Kibale National Park (Uganda). We tested whether levels of three urinary markers of oxidative damage vary among individuals in relation to their ranging patterns, as a proxy for pesticide exposure intensity. To better characterize the foraging habitat use, the trophic level, and the energetic status of study individuals, we also quantified urinary levels of carbon and nitrogen stable isotope signatures and of C-peptide. Among the 511 pesticides screened, 18 compounds including herbicides, insecticides, and fungicides were found in the water sampled in the Western part of the home range of chimpanzees. In this area, chimpanzees used to feed on maize crops. By contrast, in the Eastern part where crop feeding was never observed, we found only seven pesticides. According to their ranging patterns and thus crop feeding frequency, the 139 urine samples collected from 43 Sebitoli chimpanzees were categorized as belonging to low, medium, and high exposure level. Chimpanzees from the high exposure zone had higher oxidative DNA damage (8-OHdG) than chimpanzees from both the low and medium exposure groups, who had similar levels of oxidative DNA damage. In addition, individuals with higher C-peptide tended to have significantly higher oxidative DNA damage and lipid peroxides. The three exposure groups had similar levels of urinary 8-isoprostanes and of urinary lipid peroxides. These results were robust for any potential confounding effect of other variables because neither age category nor sex or isotope levels were significantly associated with markers of oxidative damage. Our study points to genotoxic effects as one potential sublethal consequence of ranging in proximity of agricultural fields owing to exposure to pesticides or other unidentified sources of stress. Given our phylogenetic proximity, this information is relevant for the conservation of this species which is endangered and also sentinel for human health.

Development of a model for studying the developmental consequences of oxidative sperm DNA damage by targeting redox-cycling naphthoquinones to the Sertoli cell population.

Oxidative stress can be induced in the testes by a wide range of factors, including scrotal hyperthermia, varicocele, environmental toxicants, obesity and infection. The clinical consequences of such stress include the induction of genetic damage in the male germ line which may, in turn, have serious implications for the health and wellbeing of the progeny. In order to confirm the transgenerational impact of oxidative stress in the testes, we sought to develop an animal model in which this process could be analysed. Our primary approach to this problem was to induce Sertoli cells (robust, terminally differentiated, tissue-specific testicular cells whose radioresistance indicates significant resistance to oxidative stress) to generate high levels of reactive oxygen species (ROS) within the testes. To achieve this aim, six follicle-stimulating hormone (FSH) peptides were developed and compared for selective targeting to Sertoli cells both in vitro and in vivo. Menadione, a redox-cycling agent, was then conjugated to the most promising FSH candidate using a linker that had been optimised to enable maximum production of ROS in the targeted cells. A TM4 Sertoli cell line co-incubated with the FSH-menadione conjugate in vitro exhibited significantly higher levels of mitochondrial ROS generation (10-fold), lipid peroxidation (2-fold) and oxidative DNA damage (2-fold) than the vehicle control. Additionally, in a proof-of-concept study, ten weeks after a single injection of the FSH-menadione conjugate in vivo, injected male mice were found to exhibit a 1.6 fold increase in DNA double strand breaks and 13-fold increase in oxidative DNA damage to their spermatozoa while still retaining their ability to initiate a pregnancy. We suggest this model could now be used to study the influence of chronic oxidative stress on testicular function with emphasis on the impact of DNA damage in the male germ line on the mutational profile and health of future generations.

Hepatotoxic effect of dietary phytoestrogens on juvenile cultured Russian sturgeon (Acipenser gueldenstaedtii)

In the last two decades, much controversy has grown over the use of soybean products in aquafeeds, especially for carnivorous fish like sturgeons. One point of discussion is the effect of soybean phytoestrogens on fish health. There are many aspects of phytoestrogen utilization in aquafeeds, therefore, the aim of this study is to verify if common legume phytoestrogens can affect juvenile cultured sturgeon erythrocyte and hepatocyte genotoxicity and cause liver pathology. Russian sturgeons were fed from 100 till 365 dph11Days post hutching. with daidzein, genistein, and coumestrol supplemented diets in concentrations: 10, 0.05 and 0.001 g kg−1 of feed, respectively. The SCGE22Single Cell Gel Electrophoresis (comet assay). method combined with qPCR of three genes involved in DNA repair and genome maintenance, namely cyp1a1, gaad45a and p53 were analyzed. The results were compared with histopathological evaluation of liver tissue. In fish fed with coumestrol supplemented diet, DNA strand damage was the highest in both erythrocytes and hepatocytes, however, simultaneously the lowest level of oxidative DNA damage was found. Additionally, slightly elevated expression of the p53 gene was observed along with a decreased number of apoptotic hepatocytes, which suggests that low concentration of coumestrol may support DNA repair mechanisms in the liver. Although, daidzein showed a preventive effect only against fibrosis. Isoflavones did not show a significant effect on DNA damage in studied cells. Genistein was found to increase macro- and microvesicular steatosis, portal hepatitis and fibrosis, indicating its negative role in the development of liver injuries. Daidzein alleviated some sturgeon liver damage, especially macrovesicular steatosis and interface hepatitis. However, it increased hepatocyte apoptosis, which may suggest daidzein potentially inducing liver injury, though not manifested by other histopathological lesions. Therefore, it can be concluded that at given concentrations, the tested phytoestrogens did not show clearly hepatoprotective effect in sturgeons.

Construction of Models To Predict the Effectiveness of E-Waste Control through Capture of Volatile Organic Compounds and Metals/Metalloids Exposure Fingerprints: A Six-Year Longitudinal Study.

The significant health implications of e-waste toxicants have triggered the global tightening of regulation on informal e-waste recycling sites (ER) but with disparate governance that requires effective monitoring. Taking advantage of the opportunity to implement e-waste control in the Guiyu ER since 2015, we investigated the temporal variations in levels of oxidative DNA damage, 25 volatile organic compound metabolites (VOCs), and 16 metals/metalloids (MeTs) in urine in 918 children between 2016 and 2021 to demonstrate the effectiveness of e-waste control in reducing population exposure risks. The hazard quotients of most MeTs and levels of 8-hydroxy-2'-deoxyguanosine in children decreased significantly during this time, indicating that e-waste control effectively reduces the noncarcinogenic risks of MeT exposure and levels of oxidative DNA damage. Using mVOC-derived indexes as a feature, a bagging-support vector machine algorithm-based machine learning model was constructed to predict the extent of e-waste pollution (EWP). The model exhibited excellent performance with accuracies >97.0% in differentiating between slight and severe EWP. Five simple functions established using mVOC-derived indexes also had high accuracy in predicting the presence of EWP. These models and functions provide a novel human exposure monitoring-based approach for assessing e-waste governance or the presence of EWP in other ERs.

#2629 ROS-SCAVENGING BLOCKS GLUCOSE INDUCED OXIDATIVE PERITONEAL CELL DAMAGE IN VITRO

Abstract Background and Aims Peritoneal dialysis (PD) is an effective method of renal replacement therapy (RRT). The long-term use of PD as RRT is limited due to adverse effects of high glucose-based PD fluids (PDFs) to the structure and function of the peritoneal membrane. Our group recently elucidated one pathological mechanism showing that glucose-based PDFs enhance oxidative DNA-damage in PD patients due to reduced thioredoxin (TRX) activity trigged by thioredoxin-interacting-protein (TXNIP) upregulation (Oberacker et al., 2022). Therefore, the aim of this in vitro study was to investigate drug treatments to mitigate oxidative stress and oxidative DNA-damage due to glucose-dependent induction of TXNIP expression. Method Using a mesotheliomal cell line (NCl-H28, ATCC) we performed in vitro studies mitigating reactive oxygen species (ROS) production and oxidative DNA damage as well. Cells were treated for three and eight hours with high-glucose media (1.5%, 2.3% and 4.25% glucose; glucose concentrations were adapted to PDFs from Fresenius Medical Care) compared to control media (normal glucose concentration). mRNA expression of TXNIP, TRX and further redox-related genes like superoxide dismutases (SODs) or catalase were analyzed by qPCR. Since TRX is negatively regulated by TXNIP, we investigated TRX activity in cell lysates. ROS production was monitored using a bioluminescent assay and immunofluorescence using the redox dye CellRoxGreen as well. The content of oxidative DNA-damage was investigated by immunofluorescence. Furthermore, we have preliminary analysis using primary human peritoneal mesothelial cells derived from PD effluent (PDF). Results We demonstrated a dose-dependent upregulation of round 1.5 fold TXNIP expression on mRNA level. However, no change in the expression of TRX, SODs and catalase could be observed. Interestingly, we observed a 20% reduction in TRX activity upon glucose stimulation compared to cells treated with control media. These findings are consistent with the previously published data on human peritoneal biopsies. Beyond, we demonstrated a dose-dependent increase in ROS production and increase in oxidative DNA-damage. However, ROS production and oxidative DNA damage could be prevented upon pre-incubation with the ROS-scavenger N-acetylcysteine (NAC). Conclusion Here, we show that enhanced levels of ROS and oxidative DNA damage due to glucose induced TXNIP expression could be diminished using ROS scavengers. These findings show that further antioxidative substances may be potential drugs, which could also be potential drug candidates for use in clinical practice to treat PD patients.

Maternal effect senescence via reduced DNA repair ability in the three-spined stickleback.

Maternal effect senescence, a decline in offspring viability with maternal age, has been documented across diverse animals, but its mechanisms remain largely unknown. Here, we test maternal effect senescence and explore its possible molecular mechanisms in a fish. We compared the levels of maternal mRNA transcripts of DNA repair genes and mtDNA copies in eggs and the levels of DNA damage in somatic and germline tissues between young and old female sticklebacks. We also tested, in an in vitro fertilization experiment, whether maternal age and sperm DNA damage level interactively influence the expression of DNA repair genes in early embryos. Old females transferred less mRNA transcripts of DNA repair genes into their eggs than did young females, but maternal age did not influence egg mtDNA density. Despite a higher level of oxidative DNA damage in the skeletal muscle, old females had a similar level of damage in the gonad to young females, suggesting the prioritization for germline maintenance during ageing. The embryos of both old and young mothers increased the expression of DNA repair genes in response to an increased level of oxidative DNA damage in sperm used for their fertilization. The offspring of old mothers showed higher rates of hatching, morphological deformity and post-hatching mortality and had smaller body size at maturity. These results suggest that maternal effect senescence may be mediated by reduced capacity of eggs to detect and repair DNA damages, especially prior to the embryonic genomic activation.

High anesthetic exposure leads to oxidative damage and gene expression changes in physicians during medical residency: a cohort study.

Evaluation of the possible toxic effects of occupational exposure to anesthetics is of great importance, and the literature is limited in assessing the possible association between occupational exposure to anesthetics and oxidative stress and genetic damage. To contribute to the gap of knowledge in relation to cause-effect, this cohort study was the first to monitor exposure assessment and to evaluate oxidative stress, DNA damage, and gene expression (OGG1, NRF2, HO-1, and TP53) in young adult physicians occupationally exposed to the most modern halogenated anesthetics (currently the commonly used inhalational anesthetics worldwide) in addition to nitrous oxide gas during the medical residency period. Therefore, the physicians were evaluated before the beginning of the medical residency (before the exposure to anesthetics-baseline), during (1 1/2 year) and at the end (2 1/2 years) of the medical residency. Anesthetic air monitoring was performed in operating rooms without adequate ventilation/scavenging systems, and biological samples were analyzed for lipid peroxidation, protein carbonyl content, primary and oxidative DNA damage, antioxidant enzymes and plasma antioxidant capacity, and expression of some key genes. The results showed induction of lipid peroxidation, DNA damage, glutathione peroxidase activity, and NRF2 and OGG1 expression up to the end of medical residency. Plasma antioxidant capacity progressively increased throughout medical residency; oxidative DNA damage levels started to increase during medical residency and were higher at the end of residency than at baseline. Protein carbonyls increased during but not at the end of medical residency compared to baseline. The antioxidant enzyme superoxide dismutase activity remained lower than baseline during and at the end of medical residency, and HO-1 (related to antioxidant defense) expression was downregulated at the end of medical residency. Additionally, anesthetic concentrations were above international recommendations. In conclusion, high concentrations of anesthetic in the workplace induce oxidative stress, gene expression modulation, and genotoxicity in physicians during their specialization period.

Polydatin reduces aflatoxin-B1 induced oxidative stress, DNA damage, and inflammatory cytokine levels in mice.

This study showed the protective effect of polydatin (PD), which has an antioxidant activity against oxidative stress in mice caused by aflatoxin B1 (AFB1). In this study, 36 male Swiss albino mice were divided equally into 6 groups: 0.2mL of FTS was administered to the control group, 0.2mL of olive oil to the second group, and 0.75mg/kg AFB1 to the third group by intragastric gavage every day for 28days. The fourth, fifth, and sixth groups were administered 50, 100, and 200mg/kg PD and 0.75mg/kg AFB1 intragastrically for 28days, respectively. AFB1 administration increased plasma aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, creatinine, and malondialdehyde levels in blood and tissue samples but decreased the level of glutathione and the activities of superoxide dismutase and catalase. On the other hand, it was determined that PD applications depending on the increasing doses brought these levels closer to normal. In addition, AFB1 administration increased the amount of ssDNA and liver COX-2, TNF-α, IL-6, NFκB, and Cyp3a11 mRNA expression levels; on the other hand, it decreased the IL-2 mRNA expression level. In contrast, increasing doses of PD application regulated the amount of ssDNA and these mRNA expression levels. Additionally, histopathological damage was observed in the liver and kidney tissues of the AFB1 group, while PD applications in a dose-dependent manner improved these damages. As a result, it was determined that PD reduced AFB1-induced oxidative stress, DNA damage, and inflammation and exhibited a protective effect on tissues in mice.

Indices of Inflammation, Oxidative Stress and DNA damage in T2DM patients with and without Insulin Therapy

Background: Type 2 Diabetes Mellitus is a metabolic disorder associated with excessive free radical generation and oxidative stress. Pharmacological interventions of T2DM targets on glycemic control and reduce the circulatory levels of oxidative stress and inflammation. Aim: The study compared the levels of oxidative stress, inflammation and the extent of DNA damage in T2DM patients undergoing different treatment modalities. Methods: 150 subjects recruited for this study belonged to the age group of 35-65 years. Participants were grouped as healthy controls (n=50), diabetics treated with oral hypoglycemic agent metformin (n=50) and diabetics undergoing combined therapy of insulin and metformin (n = 50). All the participants underwent the assessment of anthropometric measures, baseline blood pressure and blood samples were analysed for FBS, HbA1c, MDA, TAC, Hs-CRP and DNA damage. Results: Analysis using one-way ANOVA showed that despite the same age and duration of T2DM, patients in insulin therapy group had significantly higher levels of oxidative stress, inflammation and DNA damage when compared to T2DM patients treated with metformin alone. Further, significant correlations were observed for the above parameters with the duration of T2DM.Conclusion: The study concludes that oxidative stress, systemic inflammation and cellular senescence are more prominent in T2DM patients undergoing insulin therapy. Poor glycemic control observed in these patients could be attributed to increased insulin resistance as a consequence of oxidative stress and inflammation.

Abstract 1569: OXC-101 kills cancer by disturbing microtubule polymerization and inhibiting MTH1

Abstract Many cancers suffer from replication stress, oxidative stress, a dysfunctional redox status, and high levels of endogenous oxidative DNA damage. OXC-101 (karonudib, TH1579) targets these vulnerabilities by stopping the cancer cells in mitosis, generating ROS which increases oxidative stress and oxidative DNA damage, thereby killing the cancer cells. The aim of this study was to further investigate the underlying mechanism of OXC-101 and the cancer specific effects in solid cancers. Using e.g. microtubule polymerization assays, co-immunoprecipitation and immunofluorescence microscopy, we show a dual mechanism of action of OXC-101, disturbing microtubule function and inhibiting the nucleotide pool sanitizing enzyme MTH1. Furthermore, we demonstrate the importance of a functional spindle assemble checkpoint (SAC) for the response of OXC-101, since knocking down MAD2,using siRNA, or inhibiting SAC with reversine, results in treatment resistance. We show that the excess of oxidized nucleotides is cytotoxic when inhibiting or knocking out MTH1 in zebrafish embryos, and that pretreatment with ROS scavenger rescues the effect of OXC-101 in cancer cells. These data indicate that the increased incorporation of oxidized nucleotides into DNA is, together with the mitotic arrest, an important part of the mechanism of action and response. OXC-101 has a broad anti-cancer effect. In an ex vivo drug sensitivity study of 157 primary biopsies from solid cancer patients, OXC-101 was efficacious in a large proportion of the patient derived samples, with best responses in endometrial (73%), HNSCC (73%), bladder (70%) and prostate (83%) cancer samples. Biomarker searches for genetic alterations explaining responders/non-responders are presently on-going. In summary, the dual mechanism of action of the mitotic MTH1 inhibitor OXC-101 explains its strong anti-cancer effect. Citation Format: Ulrika Warpman Berglund, Helge Gad, Kumar Sanjiv, Ann-Sofie Jemth, Oliver Mortusewics, Lars Brautigam, Juha Rantala, Thomas Helleday. OXC-101 kills cancer by disturbing microtubule polymerization and inhibiting MTH1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1569.

Evaluating the antioxidant activity of secondary metabolites of endophytic fungi from Hypericum perforatum L. by an electrochemical biosensor based on AuNPs/AC@CS composite

Due to the variety and activity of secondary metabolites of endophytic fungi (SMEF) from medicinal plants, and the operation cumbersome of existing methods for evaluating the activity, there is urgent to establish a simple, efficient and sensitive evaluation and screening technology. In this study, the prepared chitosan functionalized activated carbon (AC@CS) composite as the electrode substrate material was used to modify glassy carbon electrode (GCE), and the gold nanoparticles (AuNPs) was deposited on AC@CS/GCE by cyclic voltammetry (CV). A ds-DNA/AuNPs/AC@CS/GCE electrochemical biosensor for evaluating the antioxidant activity of SMEF from Hypericum perforatum L. (HP L.) was fabricated using the method of layer by layer assembly. The experimental conditions affecting the evaluation results of the biosensor were optimized by square wave voltammetry (SWV) using Ru(NH3)63+ as the probe, and the antioxidant activity of various SMEF from HP L. was evaluated by the proposed biosensor. Meanwhile, the results of the biosensor were also verified by UV–vis. According to the optimized experimental results, the biosensors had a high levels of oxidative DNA damage at pH 6.0 and Fenton solution system with Fe2+ to OH− ratio of 1:3 for 30 min. Among the crude extracts of SMEF from roots, stems and leaves of HP L., the crude extracts from stems presents a high antioxidant activity, but it was weaker than l-ascorbic acid. This result was consistent with the evaluation results of UV–vis spectrophotometric method, also the fabricated biosensor presents high stability and sensitivity. This study not only provides a novel, convenient and efficient way for rapid evaluating the antioxidant activity of a wide variety of SMEF from HP L., but also provides a novel evaluation strategy for the SMEF from medicinal plants.

Evaluating the Levels of Oxidative DNA Damage, Antioxidant Profile and Pro-inflammatory Cytokines in Lung Cancer Patients

Eight-hydroxyguanosine (8-OHdG) is considered as one of the principle forms of oxygen radicals that stimulated the oxidative stress and has been extensively utilized as a biomarker for oncogenesis. The primary goal of the present study was to investigate the alteration in the levels of 8-OHdG, antioxidant profile and proinflammatory cytokines levels in patients with lung carcinoma. Blood samples were collected from 40 cases with lung cancer (stage III) admitted before the treatment, for health examination at the Nanakaly Hospital in Erbil city and 45 healthy samples of controls with ages ranging between 38-69 years for both groups. Circulating concentration of 8-OHdG, tumor necrosis factor and interleukin-6 were evaluated by ELISA. Circulating levels of superoxide dismutase (SOD), peroxidase (POX) and ascorbic acid (vitamin C) levels were also analyzed by using ELISA. The current work proposes that (8-OHdG) can be used as a functional biological marker, considering oxidative stress among the patients with lung carcinoma. The obtained data also indicated a correlation between serum cytokine concentrations and the rate of survival in lung carcinoma patients.