Prospective Protective Effect of Ellagic Acid as a SIRT1 Activator in Iron Oxide Nanoparticle-Induced Renal Damage in Rats

Ellagic acid ameliorates aging-induced renal oxidative damage through upregulating SIRT1 and NRF2

BACKGROUND

Aging is associated with impaired renal function and structural alterations. Oxidative stress plays a vital role in renal senescence and damage. Sirtuin 1 (SIRT1) is thought to protect cells from oxidative stress through nuclear factor erythroid 2-related factor 2 (NRF2). Ellagic acid (EA), a natural antioxidant, has been demonstrated to have renoprotective roles in vitro and in vivo. This study investigated if SIRT1 and NRF2 mediate the protective effects of EA in aged kidneys.

METHODS

Male Wistar rats were divided into three groups including young (4 months), old, and old + EA (25 months). Young and old groups received EA solvent, while the old + EA group was treated with EA (30 mg/kg) by gavage for 30 days. Then, the level of renal oxidative stress, SIRT1 and NRF2 expression, kidney function parameters, and histopathological indices were measured.

RESULTS

Treatment with EA significantly increased the level of antioxidant enzymes and reduced malondialdehyde concentration (P < 0.01). Moreover, EA administration remarkably upregulated mRNA and protein levels of SIRT1 and NRF2 as well as deacetylated NRF2 protein (P < 0.05). Additionally, EA treated rats improved kidney function and histopathological scores (P < 0.05).

CONCLUSIONS

These findings suggest that ellagic acid exerts protective effects on aged kidneys by activating SIRT1 and NRF2 signaling.

Superparamagnetic Iron Oxide Nanoparticles Induce Apoptosis in HT-29 Cells by Stimulating Oxidative Stress and Damaging DNA

Nanoparticles have garnered considerable scientific attention in recent years due to their diagnostic and therapeutic applications in cancer. The purpose of this study was to determine the effect of superparamagnetic iron oxide nanoparticles (Fe₃O₄ MNPs) on the induction of apoptosis in human colorectal adenocarcinoma cell line (HT-29) cells. The purpose of this study was to elucidate the mechanisms of apoptosis induced by Fe₃O₄ MNPs following MTT assay and to determine the optimal dose of 2.5 g/mL for inducing apoptosis in HT-29 cells. In HT-29 cells, Fe₃O₄ MNPs increased reactive oxygen species (ROS), calcium ion (Ca²⁺), and DNA damage. Additionally, the Fe₃O₄ MNPs significantly increased caspase 3 and 9 expression and decreased Bcl-2 expression at the protein and mRNA levels when compared to the control group (P = 0.0001). Fe₃O₄ MNPs also induced apoptosis in cancer cells by increasing the level of (ROS) and intracellular Ca²⁺, followed by an increase in caspase 3 and 9 expression and a decrease in Bcl-2 expression and direct DNA damage. Fe₃O₄ MNPs are an appropriate choice for colon cancer treatment based on their cell toxicity and induction of apoptosis in HT29 cells.

Resveratrol reversed ambient particulate matter exposure-perturbed oscillations of hepatic glucose metabolism by regulating SIRT1 in mice

Much evidence has shown that ambient particulate matter (PM) exposure is associated with abnormal glucose metabolism, but the underlying mechanism has not yet been fully characterized. Circadian disruption has adverse effects on glucose metabolism. In this study, we investigated the effects of long-term ambient PM exposure on the hepatic circadian clock and the expression rhythm of genes associated with hepatic glucose metabolism in mice. C57BL/6 mice were exposed to filtered air (FA), ambient PM, or ambient PM plus resveratrol (RES). After 15 weeks (12 h per day, 7 days per week) of exposure, glucose homeostasis, the rhythmic expression of clock genes, and genes associated with hepatic glucose metabolism were determined. Our results found that PM exposure induced glucose metabolism disorder and perturbed the rhythmic mRNA expression of core clock genes and their target genes involved in hepatic glucose metabolism. Mechanistic investigations demonstrated that ambient PM exposure markedly altered the expression patterns of BMAL1, clock, and SIRT1 in vivo. Simultaneously, we demonstrated that RES (an activator of SIRT1) changed the expression pattern of SIRT1, thereby reversing the rhythm misalignment of BMAL1 and clock and hepatic glucose metabolism disorder induced by ambient PM exposure. In addition, PM_2.5 exposure perturbed the rhythmic protein expression of BMAL1, clock, and SIRT1 in L-02 cells. Simultaneously, we demonstrated that RES restored the SIRT1 circadian rhythm, which reversed the rhythm misalignment of BMAL1 and clock in L-02 cells induced by PM_2.5 exposure. Taken together, our results suggested that long-term ambient PM exposure perturbed the hepatic core circadian clock rhythm and caused glucose metabolism disorder, which could be reversed by RES supplementation. Our study offers a potential application of RES for combating circadian misalignment-related metabolic diseases.

Bee Pollen as Functional Food: Insights into Its Composition and Therapeutic Properties

Bee pollen is a hive product made up of flower pollen grains, nectar, and bee salivary secretions that beekeepers can collect without damaging the hive. Bee pollen, also called bee-collected pollen, contains a wide range of nutritious elements, including proteins, carbs, lipids, and dietary fibers, as well as bioactive micronutrients including vitamins, minerals, phenolic, and volatile compounds. Because of this composition of high quality, this product has been gaining prominence as a functional food, and studies have been conducted to show and establish its therapeutic potential for medical and food applications. In this context, this work aimed to provide a meticulous summary of the most relevant data about bee pollen, its composition—especially the phenolic compounds—and its biological and/or therapeutic properties as well as the involved molecular pathways.

Pretreatment of ellagic acid protects ifosfamide-induced acute nephrotoxicity in rat kidneys: A mitochondrial, histopathological and oxidative stress approaches

Ifosfamide (IFO) kidney damage is an important organ toxicity in children and adults undergoing chemotherapy. Previous evidence has shown that IFO toxic metabolites such as acrolein and are associated with mitochondrial dysfunction, depletion of antioxidants, oxidative stress and may predispose the kidney to IFO toxicity. Bioactive food compounds such as ellagic acid (EA) found in fruits has been described as antioxidant and mitochondrial protective agents against toxicity-related mitochondrial damage and oxidative stress. In current study, the protective effects of EA on IFO-induced nephrotoxicity in male Wistar rats were investigated with histopathological, biochemical, and mitochondrial methods. The rats were randomly divided into four groups, control, IFO, IFO + EA, and EA groups. EA (25 mg/kg, i.p. daily) were administered to animals for 2 consecutive days and IFO (500 mg/kg, i.p.) was administered on third day. The results showed that pretreatment EA significantly increased mitochondrial succinate dehydrogenases (SDH) activity, and protected mitochondrial swelling, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) formation, lipid peroxidation (LPO) and depletion glutathione (GSH). Histopathological findings demonstrated that EA had protective effects and reduced histopathological abnormalities caused by IFO. These results showed that EA administration protects the kidneys against mitochondrial dysfunction, oxidative stress and histopathological abnormality induced by IFO. Taken together, our results demonstrated that EA played a protective role against IFO-induced nephrotoxicity through mitochondrial protection and antioxidant properties.

Thermal stress and TiO2 nanoparticle-induced oxidative DNA damage and apoptosis in mouse hippocampus

Titanium dioxide (nano-TiO₂) is used abundantly in various industrial products and novel medical therapies. In addition, the impact of climate change on the health and safety will undoubtedly increase in the future. However, the effects of exposure to these nanoparticles and heat stress on hippocampal DNA damage and apoptosis remain unclear. This study was conducted to evaluate the DNA damage and apoptosis in the hippocampal tissue and the physiological responses in mice induced by intraperitoneal (i.p.) administration of TiO₂ nanoparticles (NPs) and heat stress for 14 consecutive days. The results showed that heat stress and TiO₂-NPs were induced in the mouse hippocampus that led to hippocampal reactive oxygen species generation, oxidative damage of DNA, and apoptosis in a partly dose-dependent manner, especially at very hot temperature. High doses of nanosized TiO₂ and severe heat stress significantly damaged the function of the hippocampus, as shown in the comet assay and apoptosis tests. The results of this study may provide data for appropriate measures to control and assess the risk of nano-TiO₂ and thermal stress hazards to human health, especially workers. Safety guidelines and policies should be considered when handling nanomaterials in a hot environment.

Protective activities of ellagic acid and urolithins against kidney toxicity of environmental pollutants: A review

Oxidative stress and inflammation are two possible mechanisms related to nephrotoxicity caused by environmental pollutants. Ellagic acid, a powerful antioxidant phytochemical, may have great relevance in mitigating pollutant-induced nephrotoxicity and preventing the progression of kidney disease. This review discusses the latest findings on the protective effects of ellagic acid, its metabolic derivatives, the urolithins, against kidney toxicity caused by heavy metals, pesticides, mycotoxins, and organic air pollutants. We describe the chelating, antioxidant, anti-inflammatory, antifibrotic, antiautophagic, and antiapoptotic properties of ellagic acid to attenuate nephrotoxicity. Furthermore, we present the molecular targets and signaling pathways that are regulated by these antioxidants, and suggest some others that should be explored. Nevertheless, the number of reports is still limited to establish the efficacy of ellagic acid against kidney damage induced by environmental pollutants. Therefore, additional preclinical studies on this topic are required, as well as the development of well-designed clinical trials.

Differential aggregation of polystyrene and titanium dioxide nanoparticles under various salinity conditions and against multiple proteins types

The interaction of nanoplastics (NPls) and engineered nanoparticles (ENPs) with organic matter and environmental pollutants is particularly important. Therefore, their behavior should be investigated under the different salinity conditions, mimicking rivers and coastal environments, to understand this phenomenon in those areas. In this work, we analyzed the elementary characteristics of polystyrene-PS (unmodified surface and modified with amino or carboxyl groups) and titanium dioxide-TiO2 nanoparticles. The effect of salinity on their colloidal properties was studied too. Also, the interaction with different types of proteins (bovine serum albumin-BSA and tilapia proteins), as well as the formation of the BSA corona and its effect on the colloidal stability of nanoparticles, were evaluated. The morphology and dispersion of sizes were more uniform in unmodified-surface PS-NPs (70.5 ± 13.7 nm) than in TiO2-NPs (131.2 ± 125.6 nm). Likewise, Rama spectroscopy allowed recognizing peaks associated with the PS phenyl group aromatic ring in unmodified-surface PS-NPs (621, 1002, 1582, and 1602 cm^-1). For TiO2-NPs, the data suggest belonging to the tetragonal form, also known as rutile (445, 610 cm^-1). The elevation of salinity dose-dependently decreased NP colloid stability, with more significant variation in the PS-NPs compared to TiO2-NPs. The organic matter is also involved in this phenomenon, differentially as a function of time compared to its absence (unmodified-surface PS-NPs 30 psu/TOC 5 mgL^-1/24 h: 2876.6 ± 378.03 nm; unmodified-surface PS-NPs 30 psu/24 h: 2133 ± 49.57 nm). In general, the TiO2-NPs demonstrated greater affinity with all proteins tested (0.066 g/L). It was observed that morphology, size, and surface chemical modification intervene in a relevant way in the interaction of the nanoparticles with bovine serum albumin (unmodified-surface PS-NPs 298 K: 6.08E⁺⁰²; 310 K: 6.63E⁺⁰²; TiO2-NPs 298 K: 8.76E⁺⁰²; 310 K: 1.05E⁺⁰³ L mol^-1) and tilapia tissues proteins (from blood, gills, liver, and brain). Their morphology and size also determined the protein corona formation and the NPs' agglomeration. These findings can provide references during knowledge transfer between NPls and ENPs.

Ellagic acid ameliorates hexavalent chromium-induced renal toxicity by attenuating oxidative stress, suppressing TNF-α and protecting mitochondria

Nephrotoxicity is an important adverse effect of oxidative stress induced by hexavalent chromium [Cr(VI)]. The effect of ellagic acid, a dietary polyphenolic compound with potent antioxidant activity, was investigated in Cr(VI)-induced kidney injury. Six groups of male Wistar rats were treated intragastrically with vehicle or ellagic acid (15 and 30 mg/kg) for 10 days. On day 10, rats received saline or Cr(VI) (K₂Cr₂O₇ 15 mg/kg) subcutaneously. Cr(VI) significantly increased kidney weight, affected kidney function assessed by biomarkers in blood and urine (protein, creatinine and urea nitrogen), caused histological changes (tubular injury and glomerular capillary tuft damage), increased markers of oxidative stress and reduced the activity of antioxidant enzymes. In addition, Cr(VI) altered mitochondrial ultrastructure, impaired mitochondrial respiration, increased lipid peroxidation, and inhibited the function of mitochondrial enzymes. Pretreatment with ellagic acid (30 mg/kg) attenuated all the aforementioned alterations. Furthermore, we explored whether ellagic acid might regulate the tumor necrosis factor-alpha (TNF-α)/receptor-interacting protein kinase 3 (RIPK3) pathway, reducing Cr(VI)-induced tubular necrosis. Cr(VI) upregulated both TNF-α and RIPK3, but ellagic acid only decreased TNF-α levels, having no effect on RIPK3 content. Therefore, understanding the mechanisms through which Cr(VI) promotes necroptosis is crucial for future studies, in order to design strategies to mitigate kidney damage. In conclusion, ellagic acid attenuated Cr(VI)-induced renal alterations by preventing oxidative stress, supporting enzymatic activities, suppressing TNF-α, and preserving mitochondrial ultrastructure and function, most likely due to its antioxidant properties.

Al2O3 nanoparticles trigger the embryonic hepatotoxic response and potentiate TNF-α-induced apoptosis-modulatory effect of p38 MAPK and JNK inhibitors

Recent evidences illustrated that the release of aluminum oxide nanoparticles (Al₂O₃-NPs) into the biosphere may pose risk to the environment and cause adverse effects on living organisms including humans. The current study assessed the hepatotoxic effects of Al₂O₃-NPs on developing chicken embryo and cell culture models. Results demonstrated that Al₂O₃-NPs exposure causes histological abnormalities and increased the level of tissue damage markers (ALP, AST, and ALT) in the embryonic liver. Furthermore, increased oxidative stress (TBARS) and impaired function of antioxidant enzymes (SOD, CAT, and GPx) were also observed. Moreover, it adversely affects red blood cells (RBC) morphology, liver metabolism, and stress response gene expression (HO-1 and NQO-1). Dose-dependent ROS generation and cytotoxic response in addition to potentiating effect on tumor necrosis factor alpha (TNF-α)-induced apoptosis (caspase-3 activity) were also observed. Inhibition of p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) pathways modulates Al₂O₃-NPs-induced apoptosis in HepG2 cells. Novel mechanisms behind embryonic hepatotoxicity, cytotoxic potentiating effects, and possible prevention strategies have been explored.

Zinc oxide nanoparticles induce dose-dependent toxicosis in broiler chickens reared in summer season

This research evaluates the effect of dietary zinc oxide nanoparticles' (ZnO NPs) supplementation on growth performance, immunity, oxidative antioxidative properties, and histopathological picture of broiler chicken reared in the summer season. A total of 224 1-day-old male Cobb chicks were randomly allocated to seven groups of dietary treatments (n = 32). Seven isocaloric and isonitrogenous diets were formulated. ZnO NPs were added to the basal diet at seven different levels, 0, 5, 10, 20, 40, 60, and 80 ppm/kg diet, respectively, for 35 days. Results indicated that live body weight (g) did not differ significantly (P > 0.05) between treatment groups, whereas compared to control, the 5 ppm ZnO NPs/kg diet recorded the highest live body weight at 21 and 35 days. No significant effects for the feed consumption (g/bird/period) and feed conversion ratio (g feed/g gain) among treated and control birds were observed. Hematological and immunological variables showed significant (P ≤ 0.05) dose-dependent modulations by ZnO NP supplementation. Significant (P ≤ 0.05) differences were observed in the phagocytic activity, phagocytic index, and IgM and IgG between the treatment groups, with the 5 and 10 ppm ZnO NPs/kg diet recording the best values, followed by the 20 ppm ZnO NPs/kg diet. Different supplementations had nonsignificant effects on the digestibility of nutrients (P ≤ 0.05). Histopathological pictures of the kidney, liver, and lymphoid organs, ultrastructural examination of muscle tissues, and expression of inflammatory cytokines showed dose-dependent morphological and structural changes. In conclusion, the ZnO NP supplementation in broiler diet to eliminate the heat stress hazards in summer season is recommended in dose level of not more than 10 ppm/kg diet.

The Effect of Polyphenols on Kidney Disease: Targeting Mitochondria

Mitochondrial function, including oxidative phosphorylation (OXPHOS), mitochondrial biogenesis, and mitochondria dynamics, are essential for the maintenance of renal health. Through modulation of mitochondrial function, the kidneys are able to sustain or recover acute kidney injury (AKI), chronic kidney disease (CKD), nephrotoxicity, nephropathy, and ischemia perfusion. Therapeutic improvement in mitochondrial function in the kidneys is related to the regulation of adenosine triphosphate (ATP) production, free radicals scavenging, decline in apoptosis, and inflammation. Dietary antioxidants, notably polyphenols present in fruits, vegetables, and plants, have attracted attention as effective dietary and pharmacological interventions. Considerable evidence shows that polyphenols protect against mitochondrial damage in different experimental models of kidney disease. Mechanistically, polyphenols regulate the mitochondrial redox status, apoptosis, and multiple intercellular signaling pathways. Therefore, this review attempts to focus on the role of polyphenols in the prevention or treatment of kidney disease and explore the molecular mechanisms associated with their pharmacological activity.

Ellagic acid and cilostazol ameliorate amikacin-induced nephrotoxicity in rats by downregulating oxidative stress, inflammation, and apoptosis

Amikacin (AK) has the largest spectrum of aminoglycosides. However, its use is constrained because of nephrotoxicity and ototoxicity. Ellagic acid (EA) is a polyphenol present in plants. It has antioxidant, anticarcinogenic, and antimutagenic characteristics. Cilostazol (CTZ) is a phosphodiesterase Ш inhibitor, it is a potent vasodilator and antiplatelet drug. CTZ has an inhibitory effect on reactive oxygen species and superoxide generation in addition to hydroxyl radicals scavenging action. This study determines whether EA and cilostazol have a protective effect against AK-induced nephrotoxicity. Forty-nine rats were divided into seven equal groups: control normal; AK 400 mg/kg; EA 10 mg/kg; CTZ 10 mg/kg; AK 400 mg/kg plus EA 10 mg/kg; AK 400 mg/kg plus CTZ 10 mg/kg; AK 400 mg/kg plus EA 10 mg/kg and CTZ 10 mg/kg. For seven days, drugs were administered using gavage one hour before intramuscular injection of AK. Twenty-four hours after the last AK dosage, blood samples were collected to determine blood urea nitrogen and creatinine levels. Kidneys were removed for histopathological examination and measurement of: malondialdehyde (MDA), catalase (CAT), decreased glutathione (GSH), superoxide dismutase (SOD), interleukin 6 (IL6), tumor necrosis factor-alpha (TNFα), nuclear factor kappa B (NFκB), and Bcl-2 associated x protein (BAX). AK caused kidney damage, inflammatory mediator elevation, and oxidative stress and apoptotic markers. Rats receiving EA or CTZ indicated significant improvement in kidney function, decrease in oxidative stress and inflammation through NF-kB down-regulation and BAX expression. The combination of EA and CTZ showed a synergistic effect. In conclusion, EA and CTZ might play a beneficial role in preventing nephrotoxicity induced by AK partially by inhibition of tissue inflammation and apoptosis.

Antioxidative, anti-inflammatory and anti-apoptotic action of ellagic acid against lead acetate induced testicular and hepato-renal oxidative damages and pathophysiological changes in male Long Evans rats

Lead (Pb), is an environmental toxicant, causes multi-organ dysfunction including reproductive impairments. This study designed to investigate the prospective antioxidative, anti-inflammatory and anti-apoptotic effects of ellagic acid (EA) on Pb-mediated testicular and hepato-renal toxicity. Four experimental groups of five male Long-Evans rats each were used: control, Pb (60 mg/kg), EA (30 mg/kg), and Pb + EA groups. All groups were given their respective treatment orally for 30 days. Pb exposure altered body and organs weight, food and water consumption, rectal temperature, Pb residue levels in tissues, liver and kidney function, sperm quality parameters, serum metabolic and hematology profiles, and impaired the oxidative/antioxidative balance in the testicular and hepato-renal tissue, as shown by the decreased antioxidant proteins (superoxide dismutase, catalase, glutathione peroxidase, and reduced glutathione) and increased the oxidative (MDA, lipid hydroperoxides, conjugated dienes, protein carbonyl, fragmented DNA and GSH:GSSG ratio) stress and inflammatory (IL-1, IL-6, TNF-α, prostaglandin, LTB4, NO, myeloperoxidase, LDH) markers. Moreover, a dysregulation in the stress response (HSP-70) and apoptotic-regulating proteins (BAX, BCL-2, and active Caspase-3) were recorded upon Pb exposure. Remarkably, EA oral administration reduced the Pb residue levels in tissues, improved the liver and kidney function, revived the spermatogenesis and sperm quality, restored redox homeostasis, suppressed the oxidative stress, inflammatory and apoptotic responses in the liver, kidney and testis tissue. Our findings point out that EA can be used as a phyto-chelator to overcome the adverse effects of Pb exposure due to its potent antioxidant, anti-inflammatory, and anti-apoptotic effects.

Comparison of the Toxic Effects of Pristine and Photocatalytically Used TiO2 Nanoparticles in Mice

TiO₂ nanoparticles used in the photocatalytic degradation of pollutants in water treatment processes undergo physiochemical changes; therefore, their toxicological effects may be potentially different from those of the pristine nanoparticles. This study compared the toxic effects of exposure to pristine and photocatalytically used TiO₂ nanoparticles in mice. To obtain used TiO₂, the nanoparticles were used for photocatalytic degradation of a model pollutant under UV irradiation several times. Two groups of mice were exposed to pristine (PT group) and photocatalytically used TiO₂ (UT group) at three different concentrations (5-20 mg/m³) using whole-body exposure chambers (2 h/day, 5 days/weeks, 4 weeks). Exposure to both pristine and used TiO₂ increased the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphate (ALP), lactate dehydrogenase (LDH), C-reactive protein (CRP), and creatine kinase (CK-MB) significantly. Both exposed groups showed higher levels of WBC, lymphocytes, platelets, hematocrits, hemoglobin, and mean corpuscular volume (MCV) and lower levels of RBC and mean corpuscular hemoglobin concentration (MCHC) in a concentration-dependent manner. In all analyses, there were small non-significant differences between the PT and UT groups. More pathological changes were observed in the lung, kidney, and brain of the UT group, while the PT group showed more pathological effects in the liver and heart. The histological observations indicated that damage was mostly in the form of vascular endothelial injury. These two types of TiO₂ may activate different pathways to promote adverse effects. Further studies are required to evaluate and distinguish the mechanisms through which pristine and used TiO₂ induce toxicity.

Reproductive toxicity investigation of silica nanoparticles in male pubertal mice

Silica nanoparticles (SiNPs), one of the most produced nanoparticles (NPs) in the world, are used in all aspects of life. The increased application of SiNPs, especially in medicine, has raised considerable concern regarding their toxicological impact. Previous studies have shown that SiNPs can pass through the reproductive barrier and cause reproductive organ dysfunction by destroying Sertoli cells, Leydig cells, and germ cells. However, little is known about the mechanism of SiNPs-induced reproductive toxicity. In the present study, 5-week-old male mice were intraperitoneally administered SiNPs per day for 1 week at a dose of 0.2 mg per mouse. The results showed that SiNPs could cause damage to the structure of the testis and the epididymis and change the reproductive organ coefficients, leading to decreases of 56.1% and 55.3% in the rates of sperm concentration and motility and an increase of 168.8% in the rate of sperm abnormality. Moreover, the serum testosterone level obviously decreased from 18.77 to 5.23 µg/ml after exposure, and the transcription statuses of some key genes involved in the synthesis and transport of testosterone in the testis were also affected. Additional experiments showed that SiNPs exposure during puberty induced oxidative stress and an inflammatory response, as shown by the changed activity of superoxide dismutase (SOD), increased contents of malondialdehyde (MDA), and excess expression of proinflammatory factors, including TNF-α and IL-1β. Furthermore, the administration of SiNPs caused DNA damage and cell apoptosis, which were presented by the increased apoptotic cells in the sections of testis and epididymis and activation of the TNF-α/TNFR I-mediated pro-apoptotic pathway. In conclusion, these results indicate that SiNPs exposure during puberty significantly damaged the structure and function of the testis and epididymis by inducing oxidative stress and cell apoptosis. This study provides novel insight into SiNPs-induced reproductive toxicity during puberty, which warrants a more careful assessment of SiNPs before their application in juvenile supplies.

Urolithin A prevents streptozotocin-induced diabetic cardiomyopathy in rats by activating SIRT1

This study examined the cardiac anti-cardiomyopathy (DC) protective effect of urolithin A in streptozotocin (STZ)-treated rats and investigated if this protection involves activation of SIRT1 signaling. Diabetes was induced first STZ (65 mg/kg, i.p.) before starting the experiments. Adult male rats (n = 8/group) were treated for 8 weeks as control (non-diabetic), control + urolithin A (2.5 mg/kg/i.p.), STZ, STZ + urolithin A, and STZ + urolithin A + Ex-527 (1 mg/kg/i.p.) (a SIRT1 inhibitor). With no effect on fasting glucose and insulin levels, urolithin A improved left ventricular (LV) function and structure and reduced heart weight and serum levels of cardiac markers in STZ-treated rats. Also, it prevented collagen deposition, reduced mRNA levels of Bax, cleaved caspaspe3, collagen 1A1, transforming growth factor-β1 (TGF-β1), and Smad3 but enhanced those of Bcl2 in the LVs of diabetic rats. However, urolithin A suppressed the generation of reactive oxygen species (ROS), activated the nuclear factor erythroid 2–related factor 2 (Nrf2), and increased the levels of manganese superoxide dismutase (MnSOD) and total glutathione (GSH) in the LVs of the non-diabetic and diabetic rats, In parallel, it suppressed the cardiac activity of NF-nuclear factor-kappa beta p65 (κB p65) and reduced levels of tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). Coincided with these events, urolithin A promoted higher activity, mRNA, and total/nuclear protein levels of SIRT1 and lowered the levels of acetyl-FOXO1, Nrf2, NF-κB, and p53. All these benefits of urolithin A were prevented by Ex-527. In conclusion, urolithin A protects against DC by activating SIRT signaling.

Nanoplastics-induced oxidative stress, antioxidant defense, and physiological response in exposed Wistar albino rats

Nowadays, plastic pollution and in particular nano(micro)plastics is considered as an issue of global concern in environmental samples. The present work was conducted to clarify the oxidative stress of polystyrene nanoplastics (PS-NPs) exposure and physiological response of male Wistar rats. Animals were treated orally with PS-NPs at four doses (1, 3, 6, and10 mg/kg-day) for 5 weeks. Results demonstrated the accumulation of PS-NPs through whole body scanning and also a dose-dependent increase in the production of reactive oxygen species (ROS). Alterations in antioxidant responses including serum levels of catalase (CAT) and total glutathione content were noticed, but not superoxide dismutase (SOD), pointing towards the perturbation of redox state induced by exposure conditions. Biochemical parameters viz. glucose, cortisol, lipase, lactate, lactate dehydrogenase (LDH), alkaline phosphatase, gamma-glutamyl transpeptidase (GGT), triglycerides, and urea showed a significant increase, while total protein, albumin, and globulin levels showed an appreciable decline. The pattern of associations noticed with AChE activity and biochemical responses in our study suggests the possibility that a neurobehavioral effect or dysfunctions in energy metabolism may be the potential modes of action, possibly through stress response as well as liver function. Perturbations of creatinine and uric acid levels are indeed plausible biological explanations for the association with kidney dysfunction. Although we provided a new scientific clue for exploring the biological consequences of NPs which might induce effects such as oxidative stress relating to the induction of antioxidant enzymes, the results warrant additional research with a larger sample size.

An Overview of the Beneficial Role of Antioxidants in the Treatment of Nanoparticle-Induced Toxicities

Nanoparticles (NPs) are used in many products and materials for humans such as electronics, in medicine for drug delivery, as biosensors, in biotechnology, and in agriculture, as ingredients in cosmetics and food supplements. Besides that, NPs may display potentially hazardous properties on human health and the environment as a consequence of their abundant use in life nowadays. Hence, there is increased interest of researchers to provide possible therapeutic agents or dietary supplements for the amelioration of NP-induced toxicity. This review summarizes the new findings in the research of the use of antioxidants as supplements for the prevention and alleviation of harmful effects caused by exposure of organisms to NPs. Also, mechanisms involved in the formation of NP-induced oxidative stress and protective mechanisms using different antioxidant substances have also been elaborated. This review also highlights the potential of naturally occurring antioxidants for the enhancement of the antioxidant defense systems in the prevention and mitigation of organism damage caused by NP-induced oxidative stress. Based on the presented results of the most recent studies, it may be concluded that the role of antioxidants in the prevention and treatment of nanoparticle-induced toxicity is unimpeachable. This is particularly important in terms of oxidative stress suppression.

An Overview of the Beneficial Role of Antioxidants in the Treatment of Nanoparticle-Induced Toxicities

Nanoparticles (NPs) are used in many products and materials for humans such as electronics, in medicine for drug delivery, as biosensors, in biotechnology, and in agriculture, as ingredients in cosmetics and food supplements. Besides that, NPs may display potentially hazardous properties on human health and the environment as a consequence of their abundant use in life nowadays. Hence, there is increased interest of researchers to provide possible therapeutic agents or dietary supplements for the amelioration of NP-induced toxicity. This review summarizes the new findings in the research of the use of antioxidants as supplements for the prevention and alleviation of harmful effects caused by exposure of organisms to NPs. Also, mechanisms involved in the formation of NP-induced oxidative stress and protective mechanisms using different antioxidant substances have also been elaborated. This review also highlights the potential of naturally occurring antioxidants for the enhancement of the antioxidant defense systems in the prevention and mitigation of organism damage caused by NP-induced oxidative stress. Based on the presented results of the most recent studies, it may be concluded that the role of antioxidants in the prevention and treatment of nanoparticle-induced toxicity is unimpeachable. This is particularly important in terms of oxidative stress suppression.

Elimination of oxidative stress and genotoxicity of biosynthesized titanium dioxide nanoparticles in rats via supplementation with whey protein-coated thyme essential oil

The green synthesis of metal nanoparticles is growing dramatically; however, the toxicity of these biosynthesized particles against living organisms is not fully explored. Therefore, this study was designed to synthesize and characterize TiO2-NPs, encapsulation and characterization thyme essential oil (ETEO), and determination of the bioactive constituents of ETEO using GC-MS and evaluate their protective role against TiO2-NPs-induced oxidative damage and genotoxicity in rats. Six groups of rats were treated orally for 30 days including the control group, TiO2-NPs (300 mg/kg b.w)-treated group, ETEO at low (50 mg/kg b.w) or high dose (100 mg/kg b.w)-treated groups, and TiO2-NPs plus ETEO at the two doses-treated groups. Blood and tissues were collected for different assays. The GC-MS results indicated the presence of 21 compounds belonging to phenols, terpene derivatives, and heterocyclic compounds. The synthesized TiO2-NPs were 45 nm tetragonal particles with a zeta potential of -27.34 mV; however, ETEO were 119 nm round particles with a zeta potential of -28.33 mV. TiO2-NPs administration disturbs the liver and kidney markers, lipid profile, cytokines, oxidative stress parameters, the apoptotic and antioxidant hepatic mRNA expression, and induced histological alterations in the liver and kidney tissues. ETEO could improve all these parameters in a dose-dependent manner. It could be concluded that ETEO is a promising candidate for the protection against TiO2-NPs and can be applied safely in food applications.

Neuroprotective effect of sesamol against aluminum nanoparticle-induced toxicity in rats

Alumina nanoparticles (ALNPs) are widely used causing neurobehavioral impairment in intoxicated animals and humans. Sesamol (SML) emerged as a natural phytochemical with potent antioxidant and anti-inflammatory properties. However, no study has directly tested the potential of SML to protect against AlNP-induced detrimental effects on the brain. AlNPs (100 mg/kg) were orally administered to rats by gavage with or without oral sesamol (100 mg/kg) for 28 days. In AlNP-intoxicated group, the brain AChE activity was elevated. The concentrations of MDA and 8-OHdG were increased suggesting lipid peroxidation and oxidative DNA damage. GSH depletion with inhibited activities of CAT and SOD were demonstrated. Serum levels of IL-1β and IL-6 were elevated. The expressions of GST, TNF-α, and caspase-3 genes in the brain were upregulated. Histopathologically, AlNPs induced hemorrhages, edema, neuronal necrosis, and/or apoptosis in medulla oblongata. The cerebellum showed loss of Purkinje cells, and the cerebrum showed perivascular edema, neuronal degeneration, necrosis, and neuronal apoptosis. However, concomitant administration of SML with AlNPs significantly ameliorated the toxic effects on the brain, reflecting antioxidant, anti-inflammatory, and anti-apoptotic effects of SML. Considering these results, sesamol could be a promising phytochemical with neuroprotective activity against AlNP-induced neurotoxicity.

Ellagic acid protects rats from chronic renal failure via MiR-182/FOXO3a axis

Studies showed that ellagic acid (EA) can significantly improve kidney function, but the renal-protective effects of EA and the potential mechanism require adequate elucidation. This study investigated the mechanisms of EA in chronic renal failure (CRF) injury. A rat model of CRF was established by 5/6 nephrectomy. The body weight, urine volume and urine protein content of the rat model of CRF with EA treatment (0/20/40 mg/kg/day) were recorded. Hematoxylin&eosin (H&E) staining, Masson staining and TUNEL were used for histopathological observation. Serum levels of creatinine value, blood urea nitrogen, superoxide dismutase, glutathione, malondialdehyde, tumor necrosis factor-α, interleukin-6 and intercellular cell adhesion molecule-1 were determined using enzyme-linked immunosorbent assay (ELISA) kits. The expressions of genes involved in CRF damage were detected by quantitative real-time PCR (qRT-PCR) and western blot. The relationships among EA, miR-182 and FOXO3a were verified by TargetScan 7.2, dual-luciferase assay and rescue experiments. In this study, EA treatment significantly increased the body weight, but reduced urination and urine protein content, renal tissue damage, collagen deposition, inflammation and the contents of serum creatinine (Scr), blood urea nitrogen (BUN), and malondialdehyde (MDA), and improved the antioxidant capacity of CRF rats. Moreover, EA treatment inhibited miR-182, TGF-β1, fibronectin and Bax levels, and promoted those of FOXO3a and Bcl-2 in CRF rats. Additionally, miR-182 specifically targeted FOXO3a, and effectively reduced the renal-protective effect of EA. Further research found that overexpressed FOXO3a partially reversed the inhibitory effect of miR-182 on CRF rats. Our results suggest that EA might reduce CRF injury in rats via miR-182/FOXO3a.

Nanoencapsulation of basil essential oil alleviates the oxidative stress, genotoxicity and DNA damage in rats exposed to biosynthesized iron nanoparticles

The application of essential oils in food and pharmaceutical sectors face several challenges due to their sensitivity to oxidation process. Additionally, the biosynthesis of nanometals is growing rapidly; however, the toxicity of these particles against living organisms did not well explore yet. This study aimed to determine the bioactive compounds in basil essential oil (BEO) using GC-MS, to encapsulate and characterize BEO and to evaluate its protective role against the oxidative stress and genotoxicity of biosynthesized iron nanoparticles (Fe-NPs) in rats. Six groups of male Sprague-Dawley rats were treated orally for 4 weeks included the control group, Fe-NPs-treated group (100 mg/kg b.w.); EBEO-treated groups at low (100 mg/kg b.w.) or high (200 mg/kg b.w.) dose and the groups treated with Fe-NPs plus the low or the high dose of EBEO. The GC-MS analysis revealed the identification of 48 compounds and linalool was the major compound. The average sizes and zeta potential of the synthesized Fe-NPs and EBEO were 60 ± 4.76 and 120 ± 3.2 nm and 42.42 mV and -6.4 mV, respectively. Animals treated with Fe-NPs showed significant increase in serum biochemical analysis, oxidative stress markers, cytokines, lipid profile, DNA fragmentation and antioxidant enzymes and their gene expression and severe changes in the histology of liver and kidney tissues. Administration of Fe-NPs plus EBEO alleviated these disturbances and the high dose could normalize most of the tested parameters and improved the histology of liver and kidney. It could be concluded that caution should be taken in using the biosynthesized metal nanoparticles in different application. EBEO is a potent candidate to protect against the hazards of metal nanoparticles and can be applied in food and medical applications.

Sirtuins as molecular targets, mediators, and protective agents in metal-induced toxicity

Metal dyshomeostasis, and especially overexposure, is known to cause adverse health effects due to modulation of a variety of metabolic pathways. An increasing body of literature has demonstrated that metal exposure may affect SIRT signaling, although the existing data are insufficient. Therefore, in this review we discuss the available data (PubMed-Medline, Google Scholar) on the influence of metal overload on sirtuin (SIRT) signaling and its association with other mechanisms involved in metal-induced toxicity. The existing data demonstrate that cadmium (Cd), mercury (Hg), arsenic (As), lead (Pb), aluminium (Al), hexavalent chromium (Cr^VI), manganese (Mn), iron (Fe), and copper (Cu) can inhibit SIRT1 activity. In addition, an inhibitory effect of Cd, Pb, As, and Fe on SIRT3 has been demonstrated. In turn, metal-induced inhibition of SIRT was shown to affect deacetylation of target proteins including FOXO, PGC1α, p53 and NF-kB. Increased acetylation downregulates PGC1α signaling pathway, resulting in cellular altered redox status and increased susceptibility to oxidative stress, as well as decreased mitochondrial biogenesis. Lower rates of LKB1 deacetylation may be responsible for metal-induced decreases in AMPK activity and subsequent metabolic disturbances. A shift to the acetylated FOXO results in increased expression of pro-apoptotic genes which upregulates apoptosis together with increased p53 signaling. Correspondingly, decreased NF-kB deacetylation results in upregulation of target genes of proinflammatory cytokines, enzymes, and cellular adhesion molecules thus promoting inflammation. Therefore, alterations in sirtuin activity may at least partially mediate metal-induced metabolic disturbances that have been implicated in neurotoxicity, nephrotoxicity, cardiotoxicity, and other toxic effects of heavy metals.

Biofabrication of AuNPs using Coriandrum sativum leaf extract and their antioxidant, analgesic activity

In this work, Gold nanoparticles (AuNPs) were synthesized by reducing aqueous Au metal ions upon interaction with Coriandrum sativum (C. sativum) leaf extract. The optical absorption peak for the synthesized AuNPs was obtained by using UV-visible spectroscopy within a range of 540-550 nm. The formation of diffraction peaks found at 2θ values of 78.00°, 66.05°, 44.85° and 38.48° that corresponds to the index planes (311), (220), (200), and (111) validate the effective synthesis of AuNPs. Transmission electron microscopy (TEM) was utilized to measure the size range of the spherical shaped nanoparticles, which is obtained to be 32.96 ± 5.25 nm. The peaks obtained from the FTIR results are closely linked to anthocyanins, benzophenones, flavonoids and phenols, which indicated that these biomolecules may serve as reducing agents. Additionally, studies of antioxidant function in vitro revealed that the activities of ABTS (2, 2'-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) were improved dose-dependently. Further, the results of analgesic analysis showed that the cumulative action of AuNPs and the C. sativum leaf extract in pain relief is more efficient than independent C. sativum leaf extract and the aspirin drug.

Evaluation of the in vitro anti-inflammatory and cytotoxic potential of ethanolic and aqueous extracts of Origanum syriacum and Salvia lanigera leaves

In this study, the chemical compositions of the ethanolic and aqueous extracts of the leaves of Origanum syriacum and Salvia lanigera were identified based on GC-MS spectrometric analyses. The in vitro anti-inflammatory potential of the different extracts was evaluated by determining the membrane stabilization of human red blood cells and the percent inhibition of the COX1/2, 5LOX, and sPLA2-V enzymes. Both ethanolic extracts showed maximum membrane stabilization (≤ 91%, at 100 μg/mL) compared to the aqueous extracts (≤ 45%) and the reference drug diclofenac sodium (90.75%). The membrane-stabilizing effects of the ethanolic extracts could be directly correlated to their anti-inflammatory activity. While both ethanolic fractions strongly inhibited the 5LOX and COX-1 enzymes at 100 μg/mL, only the O. syriacum ethanolic extract selectively inhibited sPLA2-V (99.35%, at 50 μg/mL). The differences in the pharmacological efficiencies of the different extracts could be attributed to the variation in their chemical compositions particularly the content of oxygenated monoterpenoids. Additionally, none of the ethanolic extracts demonstrated cytotoxicity to human colorectal cancer cell lines (HCT-116 and Lovo), even at the highest concentration tested (200 μg/mL). The safe profiles of these extracts towards the tested cell lines may be due to the absence of the toxic phthalic acid ester substances. Collectively, these findings clearly suggest that the studied ethanolic extracts of O. syriacum and S. lanigera can be considered interesting candidates for the treatment of human inflammatory diseases related to oxidative stress and microbial infections.

Dexmedetomidine reversed hypoxia/reoxygenation injury-induced oxidative stress and endoplasmic reticulum stress-dependent apoptosis of cardiomyocytes via SIRT1/CHOP signaling pathway

We aimed to investigate the protective role and mechanism of dexmedetomidine (DEX) on H9c2 cardiomyocytes after hypoxia/reoxygenation (H/R) injury. Six experimental groups were designed as follows: normal control group (group C), H/R group, H/R + DEX group, H/R + gastrodin group, H/R + Ex527 (SIRT1 inhibitor) group, and H/R + DEX + Ex527 group. Lactate dehydrogenase (LDH) activity and the levels of oxidative stress-related enzymes such as malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) were measured using corresponding commercial kits. Cell counting kit (CCK)-8 assay was used to detect cell survival rate while flow cytometry and caspase 3/7 activity were used to determine cell apoptosis, respectively. Western blot was used to detect the expression of silent information regulator 1 (SIRT1), C/EBP homologous protein (CHOP), cleaved-caspase-12/3 and pro-caspase-12/3 in each group. From our findings, when compared with H/R, H/R + Ex527 and H/R + DEX + Ex527 groups, DEX pretreatment of cells in H/R + DEX group significantly increased cell survival rate, and simultaneously reduced LDH activity, oxidative stress and the apoptosis rate of H9c2 cells with H/R injury. Moreover, DEX up-regulated SIRT1 expression level and down-regulated the levels of endoplasmic reticulum (ER) stress-related markers such as CHOP, cleaved-caspase-12 and cleaved-caspase-3, respectively. Ex527 could completely block DEX-induced upregulated expression of SIRT1, and partially blocked the DEX-induced downregulated expression levels of CHOP, cleaved-caspase-12 and cleaved-caspase-3. These results proved that DEX reversed H/R injury-induced oxidative stress and ER stress-dependent apoptosis of cardiomyocytes via SIRT1/CHOP signaling pathway.

Decreased insulin resistance in diabetic patients by influencing Sirtuin1 and Fetuin-A following supplementation with ellagic acid: a randomized controlled trial

BACKGROUND

The beneficial effects of polyphenols have been reported. This study aimed to investigate the effect of oral Ellagic acid (EA) supplement on insulin resistance (IR) and Fetuin-A and serum sirtuin1 (SIRT1) in type 2 diabetics.

METHODS

In this double-blind, randomized clinical trial, 44 diabetic patients were selected. Patients were assigned to the intervention group (22 subjects) and placebo (22 subjects) and received a capsule containing 180 mg of EA per day or placebo for eight weeks, respectively. At the beginning and end of the study, anthropometric indices, fasting plasma glucose (FPG), plasma insulin level, IR, Fetuin-A, and SIRT1 were measured. Statistical analysis was performed using SPSS software.

RESULTS

At the beginning and end of the study, there was no significant difference between the two groups regarding anthropometric indices (P > 0.05). At the end of the survey, EA supplementation significantly reduced FPG, insulin, IR, and Fetuin-A and increased SIRT1 levels compared with the placebo group (P < 0.05). However, these changes were not significant in the placebo group (P > 0.05).

CONCLUSION

EA with antioxidant properties plays an essential role in reducing the macrovascular and microvascular complications of diabetes by reducing inflammation and insulin resistance. Trial registration The protocol of this clinical trial is registered with the Iranian Registry of Clinical Trials ( http://www.IRCT.IR , identifier: IRCT20141025019669N13).

Genome-Protecting Compounds as Potential Geroprotectors

Throughout life, organisms are exposed to various exogenous and endogenous factors that cause DNA damages and somatic mutations provoking genomic instability. At a young age, compensatory mechanisms of genome protection are activated to prevent phenotypic and functional changes. However, the increasing stress and age-related deterioration in the functioning of these mechanisms result in damage accumulation, overcoming the functional threshold. This leads to aging and the development of age-related diseases. There are several ways to counteract these changes: 1) prevention of DNA damage through stimulation of antioxidant and detoxification systems, as well as transition metal chelation; 2) regulation of DNA methylation, chromatin structure, non-coding RNA activity and prevention of nuclear architecture alterations; 3) improving DNA damage response and repair; 4) selective removal of damaged non-functional and senescent cells. In the article, we have reviewed data about the effects of various trace elements, vitamins, polyphenols, terpenes, and other phytochemicals, as well as a number of synthetic pharmacological substances in these ways. Most of the compounds demonstrate the geroprotective potential and increase the lifespan in model organisms. However, their genome-protecting effects are non-selective and often are conditioned by hormesis. Consequently, the development of selective drugs targeting genome protection is an advanced direction.