Modulation of N-nitrosodiethylamine (NDEA) induced oxidative stress by vitamin E in rat erythrocytes

A systematic review on multipotent carcinogenic agent, N-nitrosodiethylamine (NDEA), its major risk assessment, and precautions

The International Agency for Research on Cancer has classified N-nitrosodiethylamine (NDEA) as a possible carcinogen and mutagenic substances, placing it in category 2A of compounds that are probably harmful to humans. It is found in nature and tobacco smoke, along with its precursors, and is also synthesized endogenously in the human body. The oral or parenteral administration of a minimal quantity of NDEA results in severe liver and kidney organ damage. The NDEA required bioactivation by CYP450 enzyme to form DNA adduct in the alkylation mechanism. Thus, this bioactivation directs oxidative stress and injury to cells due to the higher formation of reactive oxygen species and alters antioxidant system in tissues, whereas free radical scavengers guard the membranes from NDEA-directed injury in many enzymes. This might be one of the reasons in the etiology of cancer that is not limited to a certain target organ but can affect various organs and organ systems. Although there are various possible approaches for the treatment of NDEA-induced cancer, their therapeutic outcomes are still very dismal. However, several precautions were considered to be taken during handling or working with NDEA, as it considered being the best way to lower down the occurrence of NDEA-directed cancers. The present review was designed to enlighten the general guidelines for working with NDEA, possible mechanism, to alter the antioxidant line to cause malignancy in different parts of animal body along with its protective agents. Thus, revelation to constant, unpredictable stress situations even in common life may remarkably augment the toxic potential through the rise in the oxidative stress and damage of DNA.

Tartrazine Modifies the Activity of DNMT and HDAC Genes-Is This a Link between Cancer and Neurological Disorders?

In recent years, artificial additives, especially synthetic food colorants, were found to demonstrate wider properties compared to their natural equivalents; however, their health impact is still not totally mapped. Our study aimed to determine the long-term (30 and 90 days) exposure effect of one of the commonly used artificial food colorants, tartrazine, on NMRI mice. The applied dose of tartrazine referred to the human equivalent dose for acceptable daily intake (ADI). Further, we evaluated its impact on the transcription of a range of epigenetic effectors, members of the DNA methyltransferase (DNMT) as well as histone deacetylase (HDAC) families. Following the exposure, organ biopsies were collected from the lungs, kidneys, liver, and spleen, and the gene expression levels were determined by real-time quantitative reverse transcription PCR (RT-qPCR). Our results demonstrated significant upregulation of genes in the tested organs in various patterns followed by the intake of tartrazine on ADI. Since DNMT and HDAC genes are involved in different steps of carcinogenesis, have roles in the development of neurological disorders and the effect of dose of everyday exposure is rarely studied, further investigation is warranted to study these possible associations.

Evaluation of eventual toxicities of treated textile wastewater using anoxic-aerobic algal-bacterial photobioreactor

Water pollution is one of the major challenges and is of serious concern in the world. Toxicities generated by industrial activities severely deteriorate aquatic and terrestrial ecosystems during their uncontrolled discharge and accentuate water scarcity problems. An adequate treatment of released effluents seems to be mandatory. This study investigated the effect of synthetic textile wastewater (STWW) before and after an innovative algal-bacterial treatment occurred under anoxic-aerobic conditions on growth and mineral contents of radish plants. The health risk assessment was performed after the consumption of irrigated plants by rats. Results revealed a significant reduction in heavy metals content in plants irrigated with treated STWW, and rats fed with these plants showed normal health status. Rats fed with plants irrigated with raw STWW showed a disturbance of their homeostasis. The innovative treatment using algal-bacteria under anoxic-aerobic conditions succeeds to reduce the toxicity of raw STWW and provide an alternative water resource able to tackle water shortage.

Zinc Oxide Nanoparticles Ameliorate Dimethylnitrosamine-Induced Renal Toxicity in Rat

Dimethylnitrosamine (DMN) is an established carcinogen. It is toxic to several organs, viz., the liver, kidney, and lungs, and immune system. Several drugs have been used in the past to modulate its toxicity using experimental animal models. The present study was designed to investigate the effect of zinc oxide nanoparticles (ZnONPs) on renal toxicity caused by DMN in laboratory rat. Since oxidative mechanisms are mainly involved in its toxicity, the proposed study focuses on the amelioration of oxidative stress response by ZnONPs, if any. The present results show that administration of ZnONPs (50 mg/kg body weight/rat) to DMN (2 μl/100 g body weight/rat)-treated rats diminuted the concentration of malonaldehyde, H₂O₂, and NO in the kidney. However, reduced glutathione (GSH) concentration increased after ZnONP treatment. Results on glutathione S-transferase and glutathione peroxidase favored its antioxidative effects. These results are supported by the recovery of oxidative DNA damage and less pronounced histopathological changes in the kidney. It is hypothesized that ZnONPs might be toxic to renal tissue; however, its strong therapeutic/antioxidative potential helps in ameliorating DMN-induced renal toxicity in rat.

Toxicological analysis of synthetic dye orange red on expression of NFκB-mediated inflammatory markers in Wistar rats

Orange red is a food and cosmetic coloring agent made by the amalgamation of two azo dyes carmoisine and sunset yellow.The current study demonstrates the effect of different concentrations of orange red on antioxidant status, inflammatory biomarkers (TNFα, IFNγ, IL1β, IL6, COX-2, iNOS, and NFκB/p65), biochemical enzymes, and liver histology. In totality, 25 male Wistar rats were procured and arbitrarily alienated into 5 different groups each with 5 animals. Group I was taken as the control. Groups II-V were designated as treatment groups. Groups II and III were administered with (5 and 25 mg/kg b.wt.) and groups IV and V with (150 and 300 mg/kg b.wt.) of orange red via oral gavage for 30 days. It was observed that both low and high concentrations of orange red (25, 150, and 300 mg/kg) remarkably augmented the levels of serum inflammatory cytokines (TNFα, IFNγ, IL1β, and IL6) and the protein and gene expression of COX-2, iNOS, and NFκB/p65. A significant decrease in glutathione reductase, glutathione peroxidase, glutathione-S-transferase, superoxidase dismutase, and catalase activity was observed with increasing concentration of orange red. Furthermore, an increase in the level of several vital biochemical parameters and damage severity to hepatic tissue was also found dose dependent.

Carcinogenesis: Failure of resolution of inflammation?

Inflammation in the tumor microenvironment is a hallmark of cancer and is recognized as a key characteristic of carcinogens. However, the failure of resolution of inflammation in cancer is only recently being understood. Products of arachidonic acid and related fatty acid metabolism called eicosanoids, including prostaglandins, leukotrienes, lipoxins, and epoxyeicosanoids, critically regulate inflammation, as well as its resolution. The resolution of inflammation is now appreciated to be an active biochemical process regulated by endogenous specialized pro-resolving lipid autacoid mediators which combat infections and stimulate tissue repair/regeneration. Environmental and chemical human carcinogens, including aflatoxins, asbestos, nitrosamines, alcohol, and tobacco, induce tumor-promoting inflammation and can disrupt the resolution of inflammation contributing to a devastating global cancer burden. While mechanisms of carcinogenesis have focused on genotoxic activity to induce mutations, nongenotoxic mechanisms such as inflammation and oxidative stress promote genotoxicity, proliferation, and mutations. Moreover, carcinogens initiate oxidative stress to synergize with inflammation and DNA damage to fuel a vicious feedback loop of cell death, tissue damage, and carcinogenesis. In contrast, stimulation of resolution of inflammation may prevent carcinogenesis by clearance of cellular debris via macrophage phagocytosis and inhibition of an eicosanoid/cytokine storm of pro-inflammatory mediators. Controlling the host inflammatory response and its resolution in carcinogen-induced cancers will be critical to reducing carcinogen-induced morbidity and mortality. Here we review the recent evidence that stimulation of resolution of inflammation, including pro-resolution lipid mediators and soluble epoxide hydrolase inhibitors, may be a new chemopreventive approach to prevent carcinogen-induced cancer that should be evaluated in humans.

Toxicological impact of sodium benzoate on inflammatory cytokines, oxidative stress and biochemical markers in male Wistar rats

Sodium benzoate is a widely used food and pharmaceutical preservative due to its antibacterial and antifungal activity. In the present study effect of different concentrations of sodium benzoate on hepatic antioxidants, inflammatory cytokines (TNF-α, IFN-γ, IL-1β and IL-6), biochemical markers and histopathology of liver was evaluated. Twenty five adult rats (aged 1-2 months) with 5 rats per group were randomly distributed into 5 groups. Group 1 rats were used as control and all groups (1-5) were provided with water and fed ad libitum. In addition to usual water and food, rats of group 2, 3, 4 and 5 were treated with 70, 200, 400 and 700 mg/kg b.wt of sodium benzoate once a day via oral gavage for 30 days. Our results showed that activity of glutathione peroxidase (GPx), catalase (CAT), glutathione-s-transferase (GST), glutathione reductase (GR) and superoxide dismutase (SOD) in rats decreased significantly when treated with 200, 400 and 700 mg/kg b.wt of sodium benzoate. Increase in the concentration of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum total protein, albumin, globulin, urea and creatinine was found to be dose dependent. Severe histopathological damage was observed in the hepatic tissue at higher concentrations of sodium benzoate. It was noticed that high concentrations of sodium benzoate (200, 400 and 700 mg/kg b.wt) produce significant increase in inflammatory cytokine markers (TNF-α, IFN-γ, IL-1β and IL-6) in comparison to control. Sodium benzoate at concentration of 70 mg/kg b.wt did not produce any significant changes in any of the above studied parameters.

β-carotene inhibits NF-κB and restrains diethylnitrosamine-induced hepatic inflammation in Wistar rats

β-Carotene exhibits antioxidant and hepatoprotective activities via a multitude of biochemical mechanisms. However, the action mechanism involved in antioxidant and anti-inflammatory effects of this carotene in chronic liver diseases is not fully understood. In the present investigation, we have attempted to outline a plausible mechanism of β-carotene action against liver fibrosis in albino Wistar rats. To induce hepatic fibrosis, diethylnitrosamine (DEN) was administered in experimental rats for two weeks. DEN treated rats were divided into four groups, wherein each group comprised of five rats. β-Carotene supplement attenuated DEN-induced elevation in LFT markers (P < 0.05); averted depletion of glycogen (24%, P < 0.05) and, increased nitrite (P < 0.05), hydroxyproline (~67%, P < 0.05) and collagen levels (~65%, P < 0.05). Confocal microscopy of tissue sections stained with picrosirius red revealed accrued collagen in DEN-administered group, which was found to be reduced by β-carotene supplementation. Furthermore, β-carotene decreased the expression of iNOS/NOS-2 and NF-κB, as revealed by immunohistochemistry and Western immunoblotting. Collectively, these results demonstrate that β-carotene mitigates experimental liver fibrosis via inhibition of iNOS and NF-κB in-vivo. Thus, β-carotene may be suggested as a possible nutraceutical to curb experimental liver fibrosis.

Sunset Yellow and Allura Red modulate Bcl2 and COX2 expression levels and confer oxidative stress-mediated renal and hepatic toxicity in male rats

Studies on the adverse health effects caused by azo dyes are insufficient and quite contradictory. This work aims to investigate the possible toxic effect of two types of widely used food additives, Sunset Yellow and Allura Red, by assessing the physiological, histopathological and ultrastructural changes in the liver and kidney. Also, we investigated the genotoxic effect of both dyes on white blood cells. Thirty adult male albino rats were divided into three groups of 10 animals each: control (received water), Sunset Yellow-treated (2.5 mg/kg body weight) and Allura Red-treated (seven mg/kg body weight). The doses were orally applied for 4 weeks. Our results indicated an increase in the biochemical markers of hepatic and renal function (Aspartate aminotransferase, alanine aminotransferase, urea, uric acid and creatinine) in animals administered with the azo dyes. We also observed a noticeable increase in MDA and a marked decrease in total antioxidant levels in azo dye-treated animals compared to controls. Conversely, both dyes adversely affected the liver and kidney of albino rats and altered their histological and fine structure, with downregulation of Bcl2 and upregulation of COX2 expression. Our comet assay results showed a significant elevation in the fold change of tail moment in response to application of Sunset Yellow but not Allura Red. Collectively, we show that Sunset Yellow and Allura Red cause histopathological and physiological aberrations in the liver and kidney of male Wistar albino rats. Moreover, Sunset Yellow but not Allura Red induces a potential genotoxic effect.

Sequential analysis and staging of a diethylnitrosamine-induced hepatocellular carcinoma in male Wistar albino rat model

Hepatocellular carcinoma (HCC) is one of the most life-threatening cancers. The present study was designed to chronologically analyze the HCC chemically induced by diethylnitrosamine (DEN) in male Wistar rats during a 27-week period. DEN was given to rats in drinking water (100 mg/L) to induce HCC. In the present study, the DEN-administered groups recorded dramatic results in the tumor markers, oxidative stress, lipid profile, liver function, and hematological parameters at all intervals when compared with their corresponding values in the control groups. In addition, the morphometric analysis of livers of the DEN-administered groups (from 9 to 27 weeks) showed gradual enlargement and several grayish white nodules and foci on the peripheral surface of the liver as the features of HCC. In conclusion, the present sequential model chronologically analyzes all steps of hepatocarcinogenesis and presents a new staging system for classification of HCC that may be valuable for investigating the effects of anticarcinogenic compounds at varying stages of hepatocarcinogenesis in vivo.

Exploiting bilosomes for delivering bioactive polysaccharide isolated from Enteromorpha intestinalis for hacking hepatocellular carcinoma

Bile salts containing vesicles (bilosomes) represent a portentous vesicular carrier that showed prosperous results in delivering active moieties in the gastrointestinal tract (GIT). In this study, bilosomes were exploited to deliver sulfated polysaccharide-protein complexes of Enteromorpha intestinalis (EHEM) and enhance its activity against hepatocellular carcinoma as well as resist harsh GIT conditions. Bilosomes were prepared using the sodium salt of three different bile acids (cholic, deoxycholic, taurodeoxycholic) and two different nonionic surfactants (Span 40 and 65). The effects of experimental variables were thoroughly studied to obtain an optimum formulation loading EHEM. The selected formulation (EH-Bilo-2) prepared with sodium cholate and Span 65 displayed nano-sized (181.1 ± 16.80 nm) spherical vesicles with reasonable entrapment efficiency (71.60 ± 0.25%) and controlled release properties; and thus was investigated as anti-hepatocarcinogenic candidate for in vivo studies. Treatment of hepatocellular carcinoma (HCC) bearing rats with EH-Bilo-2 experienced significant decrease in serum α-fetoprotein, endoglin, lipocalin-2, and heat shock protein 70 levels vs. the untreated counterparts. Furthermore, the photomicrographs of their liver tissue sections showed focal area of degenerated pleomorphic hepatocytes with fine fibrosis originating from the portal area. Thus, the optimized bilosomal formulation is a promising delegate for tackling hepatocellular carcinoma owing to its powerful anti-cancer and anti-angiogenic activity.

Protective effect of yellow tea extract on N-nitrosodiethylamine-induced liver carcinogenesis

Context Yellow tea containing the same catechins as other types of tea but in different proportions has been suggested to possess potent anticancer activities. Objective This study investigates the chemopreventive effect of yellow tea aqueous extract against N-nitrosodiethylamine (NDEA)-induced liver carcinogenesis in rats by employing histological and biochemical methods. Materials and methods Wistar rats were divided randomly into four groups: control (I), yellow tea (II), NDEA (III), and yellow tea + NDEA (IV). Groups II and IV were exposed via a diet to yellow tea extract in a concentration of 10 g/kg feed; groups III and IV received 0.01% NDEA in drinking water. The experiment lasted for 13 weeks. Results Daily intake of yellow tea in an average dose of 800 mg/kg b.w. alleviated the carcinogenic effect of NDEA as evidenced by reversed histopathological changes towards normal hepatocellular architecture and decreased lipid peroxidation, protein carbonyl formation, and DNA degradation by 64%, 37% and 15%, respectively, as compared with values obtained in NDEA alone-treated rats. Treatment with yellow tea extract caused protection of superoxide dismutase (SOD) and catalase (CAT); their activity was recovered by 47% and 12%, respectively, as compared with the NDEA-treated rats. Moreover, the extract normalized the NDEA-induced activity of paraoxonase 1 (PON1) and glutathione peroxidase (GPx), while a further increase in the level of reduced glutathione (GSH) was noticed. Conclusions On the basis of these findings, it can be concluded that treatment with yellow tea partially protected the livers of rats from NDEA-induced hepatocarcinogenesis and that its antioxidant activity contributed to this effect.

A combination of liver fluke infection and traditional northeastern Thai foods associated with cholangiocarcinoma development

Opisthorchis viverrini infection is one of the risk factors for cholangiocarcinoma (CCA) in northeast Thailand, a region with one of the highest reported incidence rates of CCA. The traditional practice of eating raw fish, repeated exposure to liver flukes, and consumption of nitrosamine-contaminated food are major risk factors for CCA. So far, there have been no reports about which northeastern traditional dishes may be involved in CCA development. The present study, thus, investigated the effects of traditional foods. It focused specifically on the consumption of fermented foods in combination with O. viverrini infection in hamsters. Syrian hamsters were divided into six groups: (i) normal hamsters, (ii) O. viverrini infection only and (iii)-(vi) O. viverrini infection plus fermented foods (pla som-fish fermented for 1 day), som wua-fermented beef, som phag-fermented vegetables, and pla ra-fish fermented for 6 months. Syrian hamster livers were used for analysis of histopathological changes through hematoxylin and eosin; Sirius Red; and immunohistostaining for cytokeratin-19, proliferating cell nuclear antigen, and CA19-9. Hamster sera were used for liver and kidney function tests. Results of all O. viverrini-infected groups and fermented food groups showed that histopathological changes consisted primarily of aggregations of inflammatory cells surrounding the hepatic bile duct, especially at the hilar region. However, there was a difference in virulence. Interestingly, aggregations of inflammatory cells, new bile duct formation, and fibrosis were observed in subcapsular hepatic tissue, which correlated to positive immunohistochemical staining and increased liver function test. The present study suggests that fermented food consumption can exacerbate cholangitis and cholangiofibrosis, which are risk factors for cholangiocarcinoma-associated opisthorchiasis.

Fish erythrocytes as biomarkers for the toxicity of sublethal doses of an azo dye, Basic Violet-1 (CI: 42535)

The aim of the present study was to investigate poikilocytosis in Labeo rohita (an important food fish) as an early indicator of stress due to an azo dye, Basic Violet-1 (CI: 42535). This dye was observed to be very toxic to test fish (96 h LC50 as0.45 mg/L dye). Fish were given short-term (96 h) and subchronic (150 days) exposures to the dye, and poikilocytosis was recorded under light and scanning electron microscopy (SEM). Light microscopy helped in identification of micronuclei along with irregularities, notches, blebs, lobes, crenation, clumps, chains, spherocytes, vacuolation, and necrosis in erythrocytes. However, SEM indicated shrinkage, oozing of cytoplasm, and several new abnormal shapes including marginal foldings, discocytes, keratocytes, dacrocytes, degmacytes, acanthocytes, echinocytes, protuberances, stomatocytes, drepanocytes, holes in the membrane, stippling/spicules, crescent-shaped cells, triangular cells, and pentagonal cells. Earlier studies speculated changes in the membrane to be responsible for clumping and chaining of erythrocytes, whereas the present SEM study clearly indicates that oozing out of cytoplasm is also responsible for the formation of chains and clumps. This study also shows that erythrocytes exhibit pathological symptoms before the appearance of other external symptoms such as abnormal behavior or mortality of fish. There was a dose- and duration-dependent increase; therefore, poikilocytosis, especially echinocytes, spherocytes, and clumps, can act as a biomarker for the stress caused by azo dyes.

Induction of giant cells by the synthetic food colorants viz. lemon yellow and orange red

Cytotoxicity and giant cell formation induced by lemon yellow and orange red synthetic food colorants were evaluated in the present study. The aqueous solutions of both the dye solutions were tested for cytotoxicity using Allium cepa assay. Frequency of giant cells were determined after treating the root tips with different concentrations of both food colorant solutions viz., 0.005, 0.01, 0.05, 0.1 % for varying time durations (1/2, 1, 2, 3 h). These colorants may cause giant cell formation primarily by interfering with the normal course of mitosis. Giant cells showing multiple aberrations viz. bridged and binucleate condition, cellular fragmentation, nuclear lesion, double and multiple nuclear lesions, double nuclear peaks and cellular breakage, elongated nucleus, nuclear budding, hyperchromasia, micronucleus, nuclear erosion, pulverized nucleus etc. were induced in root tips treated with both of the colorants. The synthetic food colorant treated cells showed inhibition of cell division and induction of giant cells. A dose dependant decrease in the mitotic index [88.20 % (c(-ve), 3h) to 81.54 % (Lx4, 3h) and 88.20 % (c(-ve), 3h) to 73.17 % (Ox4, 3h)] was observed. All mitotic phases show significant induction of giant cells when treated with both food colorants. Interphase stage shows higher percentage of giant cells, whereas in cytokinesis it was negligible. The orange red food colorant is observed to be more toxic because it recorded higher percentage of giant cell induction when compared with lemon yellow [27.93 % (Lx4, 3h) and 28.07 % (Ox4, 3h)].

The hazardous effects of three natural food dyes on developmental stages and longevity of Drosophila melanogaster

Nowadays, food dyes obtained from herbal, animal, microbial and mineral sources are widely used as food additives. In this study, the toxic effects of three different natural food dyes (carmine, turmeric and annatto) on 72 ± 4 h larvae of Oregon-R wild type of Drosophila melanogaster were investigated. For this purpose, four different application doses (50, 75, 100, 125 mg mL(-1)) were chosen by means of preliminary studies. It was determined that larval mortality increased with increasing concentration in the application groups and the toxicity order was carmine > turmeric > annatto. It was observed that the survival rate was highest in the control with 98% and lowest in 125 mg mL(-1) carmine with 16%. In addition, the average lifespan of the adult individuals obtained from third instar larvae was also studied. While the average lifespan was 40.88 ± 1.44 days in the control group, these values were 10.81 ± 0.55-23.90 ± 1.27 days in the carmine group, 15.00 ± 0.80-22.42 ± 1.43 days in the turmeric group and 10.33 ± 1.03-35.68 ± 1.54 days in the annatto group, respectively. According to the obtained results, when both the developmental period from larvae into adults and the lifespan of the developing adults were compared with the control group, the food dyes were found to be toxic and the toxicity order of carmine > turmeric > annatto was identified.

Effect of saccharin on albino rats’ blood indices and the therapeutic action of vitamins C and E

The present work aimed to study some blood indices of rats as affected by saccharin and the therapeutic action of vitamins C and E. The used adult female Rattus norvegicus albino rats in the present study were weighing 100—120 g. Administration of saccharin at a dose of 35 mg kg—1body weight (b.wt.) day—1for 35 days significantly decreased serum glucose, triglycerides, cholesterol, total protein and albumin values. These decrements were by 20.16%, 22.76%, 44.92%, 20.16% and 40.44%, respectively, compared to control level (p value < 0.01). But it increased levels of kidney function indices. The effect of saccharin was more pronounced on creatinine. Activities of Alanine aminotranferease (ALT), aspartate aminotransferase (AST) and Alkaline phosphatase (ALP) increased significantly following saccharin treatment to rats. Concerning hematoligical parameters, the more obvious changes were observed in the increment of white blood cell (WBC), mean corpuscular volume (MCV) and platelets (PLT) and the decrease in hematocrit, hemoglobin (Hb) and red blood cells (RBCs) count in response to the administration of saccharin. In general, vitamin C or E (150 mg kg—1b.wt. day—1for 35 days) was able to reduce the effects of saccharin intake. Both vitamins, however, generally have beneficial effects in reducing the changes in the studied parameters.

Methylated chrysin, a dimethoxy flavone, partially suppresses the development of liver preneoplastic lesions induced by N-nitrosodiethylamine in rats

The modifying effect of chemically modified chrysin on formation of preneoplastic foci induced by N-nitrosodiethylamine (DEN) was investigated in male rats. Male Wistar rats were administered three intraperitoneal injections of DEN (200 mg/kg bodyweight) interspersed by 2 weeks with or without an oral dose of dimethoxy flavone (DMF 100 mg/kg bodyweight), 2 weeks after DEN initiation. The number of GST-Pi positive foci and proliferating cell nuclear antigen (PCNA)-positive cells were significantly suppressed by the administration of DMF. Real-time RT-PCR analysis revealed that DMF treatment increased mRNA expression levels of apoptotic proteins p53 and fas, cell cycle regulatory proteins chek 2, cdkn1a, rad 50, anti-inflammatory protein pparg whereas the mRNA expression levels of bcl-2 and prdx-2 were decreased compared to mRNA levels in DEN-treated group. Therefore, we propose that DMF partially suppresses the formation of preneoplastic lesions in rats following DEN exposure by regulating anti-inflammatory and apoptosis-promoting events and restoring the cellular redox balance altered by DEN.

Antioxidant Effect of CoQ(10) on N-nitrosodiethylamine-induced Oxidative Stress in Mice

The antioxidant effect of CoQ(10) on N-nitrosodiethylamine (NDEA)-induced oxidative stress was investigated in mice. Food intake and body weight were similar in both CoQ(10) and control groups during the 3-week experimental period. NDEA significantly increased the activities of typical marker enzymes of liver function (AST, ALT and ALP) both in control and CoQ(10) groups. However, the increase of plasma aminotransferase activity was significantly reduced in the CoQ(10) group. Lipid peroxidation in various tissues, such as heart, lung, liver, kidney, spleen and plasma, was significantly increased by NDEA, but this increase was significantly reduced by 100 mg/kg of CoQ(10). Superoxide dismutase activity increased significantly upon NDEA-induced oxidative stress in both the control and CoQ(10) groups with the effect being less in the CoQ(10) group. Catalase activity decreased significantly in both the control and CoQ(10) groups treated with NDEA, again with the effect being less in the CoQ(10) group. The lesser effect on superoxide dismutase and catalase in the NDEA-treated CoQ(10) group is indicative of the protective effect CoQ(10). Thus, CoQ(10) can offer useful protection against NDEA-induced oxidative stress.

Antioxidant potential of thyme extract: alleviation of N-nitrosodiethylamine-induced oxidative stress

Protective role of thyme extract against N-nitrosodiethylamine (NDEA)-induced oxidative stress has been evaluated in albino rats. For this, one group of rats were fed diet supplemented with thyme extract (0.5%) and served as the test group, whereas animals of the other group fed on normal diet served as the control group. The rats were fed on respective diets for a period of 2 weeks after which stress was induced to half the animals of each group by i.p. administration of NDEA at 200 mg/kg body weight. Animals were killed 48 h post stress-induction period. Feed intake and body weight decreased significantly in both test and control groups, the effect being less in test group. Increase in osmotic fragility and in-vitro lipid peroxidation (LPO) on stress induction was of lower degree in the test group. NDEA toxicity was mainly reflected in liver as evidenced by increased activities of plasma aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. The effect was of lower degree in test group as compared with that in the control group. Increase in urea levels observed following NDEA administration was also of lower degree in test groups. Blood glutathione (GSH) levels increased more so in test group compared with control group on stress induction. The activities of superoxide dismutase (SOD), peroxidase (Px), and catalase (CAT) activities decreased significantly on stress induction in erythrocytes. LPO increased in all the tissues through varying degree, and the increase was appreciably of lower degree in test group. The activity of SOD increased significantly in both test and control group on stress induction, whereas activities of Px and CAT decreased following NDEA treatment, and the effects were of lower degree in test group. Thus, supplementation of diet with thyme extract can improve antioxygenic potential and hence help to prevent oxidative stress.