Comparable Toxicity of Surface-Modified TiO2 Nanoparticles: An In Vivo Experimental Study on Reproductive Toxicity in Rats

Nanoparticles (NPs), a distinct class of particles ranging in size from 1 to 100 nm, are one of the most promising technologies of the 21st century, and titanium dioxide NPs (TiO2 NPs) are among the most widely produced and used NPs globally. The increased application of TiO2 NPs raises concerns regarding their global safety and risks of exposure. Many animal studies have reported the accumulation of TiO2 NPs in female reproductive organs; however, evidence of the resultant toxicity remains ambiguous. Since the surface area and chemical modifications of NPs can significantly change their cytotoxicity, we aimed to compare the toxic effects of pristine TiO2 powder with surface-modified TiO2 powders with salicylic acid (TiO2/SA) and 5-aminosalicylic acid (TiO2/5-ASA) on the ovaries, oviducts, and uterus on the 14th day following acute oral treatment. The results, based on alterations in food and water intake, body mass, organ-to-body mass ratio, hormonal status, histological features of tissues of interest, and antioxidant parameters, suggest that the modification with 5-ASA can mitigate some of the observed toxic effects of TiO2 powder and encourage future investigations to create NPs that can potentially reduce the harmful effects of TiO2 NPs while preserving their positive impacts.

Antioxidant and cytotoxic activity of red wine after in vitro simulated digestion in the presence of complex food matrix

The beneficial effect of moderate wine consumption is attributed to its micronutrients, especially polyphenols and largely depends on the digestion process. This work aimed to examine the influence of in vitro simulated digestion in the presence of complex food matrix on antioxidant and cytotoxic activity of red wine. The obtained results showed that total phenolic content of wine sample after in vitro digestion was higher compared to undigested wine, while the antioxidant activity of these samples was similar before and after digestion. Furthermore, it has been noticed that digested wine showed cytotoxic activity on SKBR3 breast adenocarcinoma cells near 20% after 72 h of treatment. This pioneering study that examined biological potential of in vitro digested wine in the presence of complex food matrix indicate that antioxidant and cytotoxic activity of red wine is preserved after digestion.

Antioxidant defense system in the prefrontal cortex of chronically stressed rats treated with lithium

Background

This study aimed to investigate the effects of lithium treatment on gene expression and activity of the prefrontal antioxidant enzymes: copper, zinc superoxide dismutase (SOD1), manganes superoxide dismutase (SOD2), catalase (CAT), and glutathione peroxidase (GPx) in animals exposed to chronic restraint stress (CRS).

Methods

The investigated parameters were quantified using real-time RT-PCR, Western blot analyses, and assays of enzyme activities.

Results

We found that lithium treatment decreased gene expression of SOD2, as well as the activities of SOD1 and SOD2 in chronically stressed rats to the levels found in unstressed animals. However, lithium treatment in animals exposed to CRS increased prefrontal GPx activity to the levels found in unstressed animals.

Conclusions

These findings confirm that treatment with lithium induced the modulation of prefrontal antioxidant status in chronically stressed rats. Our results may be very important in biomedical research for understanding the role of lithium in maintaining the stability of prefrontal antioxidant defense system in neuropsychiatric disorders caused by chronic stress.

Effects of mood stabilizer lithium on noradrenergic turnover in the prefrontal cortex of chronically stressed rats

OBJECTIVE

Data about the dynamics of noradrenaline (NA) transmission, storage and degradation may be very important for understanding the reduction of functional deficiency of NA and maintaining the stability of NA levels in animals with depressive-like behavior treated with lithium. This study aimed to investigate the effects of mood stabilizer lithium on concentrations of NA in the prefrontal cortex (PFC), as well as behavior rats exposed to chronic restraint stress (CRS). In addition, this study examined the effects of lithium on protein levels of noradrenaline transporter (NET), vesicular monoamine transporter 2 (VMAT2) and catechol-O-methyltransferase (COMT), as well as the enzyme activity of monoamine oxidase A (MOA) in the PFC of chronically stressed rats.

METHODS

The investigated parameters were quantified by Western blot analysis, CAT Research ELISA kits, and an assay of enzyme activity. Also, the forced swim test (FST) was used to assess the behavior of animals.

RESULTS

We found that lithium treatment decreased high protein levels of NET and VMAT2, as well as the enzyme activity of MOA in chronically stressed rats to the levels found in unstressed animals. In addition, lithium treatment decreased the concentration of NA (24%) and immobility in animals exposed to CRS.

CONCLUSION

Our data confirm that lithium-induced modulation of prefrontal noradrenergic turnover and stabilized the behavior of chronically stressed rats.

Antidepressants- and antipsychotics-induced hepatotoxicity

Drug-induced liver injury (DILI) is a serious health burden. It has diverse clinical presentations that can escalate to acute liver failure. The worldwide increase in the use of psychotropic drugs, their long-term use on a daily basis, common comorbidities of psychiatric and metabolic disorders, and polypharmacy in psychiatric patients increase the incidence of psychotropics-induced DILI. During the last 2 decades, hepatotoxicity of various antidepressants (ADs) and antipsychotics (APs) received much attention. Comprehensive review and discussion of accumulated literature data concerning this issue are performed in this study, as hepatotoxic effects of most commonly prescribed ADs and APs are classified, described, and discussed. The review focuses on ADs and APs characterized by the risk of causing liver damage and highlights the ones found to cause life-threatening or severe DILI cases. In parallel, an overview of hepatic oxidative stress, inflammation, and steatosis underlying DILI is provided, followed by extensive review and discussion of the pathophysiology of AD- and AP-induced DILI revealed in case reports, and animal and in vitro studies. The consequences of some ADs and APs ability to affect drug-metabolizing enzymes and therefore provoke drug–drug interactions are also addressed. Continuous collecting of data on drugs, mechanisms, and risk factors for DILI, as well as critical data reviewing, is crucial for easier DILI diagnosis and more efficient risk assessment of AD- and AP-induced DILI. Higher awareness of ADs and APs hepatotoxicity is the prerequisite for their safe use and optimal dosing.

Changes of Hippocampal Noradrenergic Capacity in Stress Condition

This study aimed to investigate the effects of chronic restraint stress (CRS) on the protein levels of dopamine-β-hydroxylase (DBH), noradrenaline transporter (NET), vesicular monoamine transporter 2 (VMAT2) and brain-derived neurotrophic factor (BDNF), as well as the concentration of noradrenaline (NA) in the rat hippocampus. The investigated parameters were quantified by Western blot analyses and ELISA kits. We found that CRS increased the protein levels of DBH by 30 %, VMAT2 by 11 %, BDNF by 11 % and the concentration of NA by 104 %, but decreased the protein levels of NET by 16 % in the hippocampus of chronically stressed rats. The molecular mechanisms by which CRS increased the hippocampal NA level are an important adaptive phenomenon of the noradrenergic system in the stress condition.

The effect of antioxidant status on overall survival in renal cell carcinoma

INTRODUCTION

The oxidative stress contributes to all three phases of carcinogenesis and represents a concomitant condition in renal cell carcinoma (RCC). RCC is the most common type of neoplasm of the kidney, and despite numerous studies the set of predictive and prognostic markers of survival are still unknown. The aim of our study was to examine the relation between antioxidant (AO) status and overall survival (OS) in RCC patients.

MATERIAL AND METHODS

Our study included 95 patients with RCC, who underwent radical nephrectomy. We analysed the prognostic role of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, glutathione, and malondialdehyde) and other clinicopathological factors (size, grade, stage, and histological subtype) on the OS of RCC patients.

RESULTS

The 5-year OS was 54.6%. The survival analysis related to AO parameters showed no significant difference in survival of RCC patients. The concentration of malondialdehyde, an indicator of lipid peroxidation, also had no significant effect on the survival rate of RCC patients. Univariate and multivariate analysis confirmed the significance of clinicopathological parameters (size, p < 0.001; Fuhrman grade, p = 0.001, and stage, p < 0.001) for patients' survival.

CONCLUSIONS

In our cohort of patients, different antioxidant parameters were not found to be predictors for OS of patients with RCC, who underwent radical nephrectomy.

Antioxidant Activity of Selected Polyphenolics in Yeast Cells: The Case Study of Montenegrin Merlot Wine

Screens of antioxidant activity (AA) of various natural products have been a focus of the research community worldwide. This work aimed to differentiate selected samples of Merlot wines originated from Montenegro, with regard to phenolic profile and antioxidant capacity studied by survival rate, total sulfhydryl groups and activities of glutathione peroxidase (GPx), glutathione reductase and catalase in H₂O₂⁻stressed Saccharomyces cerevisiae cells. In this study, DPPH assay was also performed. Higher total phenolic content leads to an enhanced AA under both conditions. The same trend was observed for catechin and gallic acid, the most abundant phenolics in the examined wine samples. Finally, the findings of an Artificial Neural Network (ANN) model were in a good agreement (r² = 0.978) with the experimental data. All tested samples exhibited a protective effect in H₂O₂⁻stressed yeast cells. Pre-treatment with examined wines increased survival in H₂O₂⁻stressed cells and shifted antioxidative defense towards GPx⁻mediated defense. Finally, sensitivity analysis of obtained ANN model highlights the complexity of the impact that variations in the concentrations of specific phenolic components have on the antioxidant defense system.

Antioxidant status and sex hormones in women with complex endometrial hyperplasia

Endometrial tissue is under a strong influence of sex hormones. These hormones are considered as developmental factors of endometrial hyperplasia and endometrial cancer. We examined the influence of gonadotropins (follicle-stimulating and luteinizing hormone) and sex hormones (estradiol, progesterone) on oxidant/antioxidant parameters in blood and endometrial tissue of women with complex endometrial hyperplasia. In blood, superoxide dismutase activity was significantly higher in luteal phase and postmenopause compared to the follicular phase. A significant phase-related difference of glutathione peroxidase and glutathione reductase activity was recorded in the endometrium. Both enzymes had lower activity in luteal phase and postmenopause compared to the follicular phase. The linear regression analysis of individual hormonal variables against antioxidant parameters showed negative correlation between glutathione peroxidase activity and gonadotropin concentrations in the endometrium. The regression of hyperplastic to normal endometrium is the purpose of conservative treatment based on administration of progestogens or gonadotropin-releasing hormone analogues. Our findings indicate that gonadotropins influence the antioxidant enzymes activity in women with complex endometrial hyperplasia, which may affect disease development. Further studies are needed to clarify the molecular basis of hormone action on antioxidant system that may potentially initiate a development of treatments based on redox-dependent mechanism.

Antioxidative enzymes in irradiated rat brain-indicators of different regional radiosensitivity

PURPOSE

Previously, we examined manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (CuZnSOD), and catalase (CAT) activities in rat brain irradiated with 2 or 3 Gy of γ-rays. The results indicated that lower MnSOD activity and inducibility found in hippocampus might explain higher radiosensitivity of this brain region. Thus, in this study, we wanted to determine changes of MnSOD, CuZnSOD, and CAT activities after dose of 5 Gy and to find out if differences in MnSOD activity are caused by changes in its expression.

METHODS

Heads of 4-day-old female rats were irradiated with γ-rays, using (60)Co. Animals were sacrificed 1/24 h after exposure. Hippocampus and cortex tissues were prepared for enzyme activity measurements and Western blot analysis.

RESULTS

One hour after exposure, γ-rays significantly decreased MnSOD activity in both examined brain regions. Twenty-four hours later, MnSOD recovery showed dose and regional dependence. It was weaker at higher doses and in hippocampal region. MnSOD expression changed in the similar manner as MnSOD activity only at lower doses of γ-rays. In both examined brain regions, gamma radiation significantly decreased CuZnSOD activity and did not change activity of CAT.

CONCLUSIONS

Our results confirmed that MnSOD plays an important role in different regional radiosensitivity but also showed that depending on dose, radiation affects MnSOD level by utterly different mechanisms. Postradiation changes of CuZnSOD and CAT are not regionally specific and therefore, cannot account for the different radiosensitivity of the hippocampus and cortex.

Antioxidant status in women with uterine leiomyoma: relation with sex hormones

Uterine leiomyomas are benign soft-tissues tumors that arise from uterine smooth muscle tissue. Etiopathogenesis of leiomyomas is not well understood. We aimed to examine whether antioxidant enzyme activities and lipid hydroperoxides level in patients with leiomyoma are influenced by changes in sex hormones and gonadotropins (estradiol (E2), progesterone, FSH, and LH) during menstrual cycle and in postmenopause. The material consisted of blood and uterine tissue specimens. Hormone concentrations were determined and assays for superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities and lipid hydroperoxides concentration were performed. In blood of examined women, a significant difference in catalase, glutathione peroxidase and glutathione reductase activity was recorded among the phases. There was also a positive correlation between the estradiol/progesterone concentration and the catalase activity. Progesterone negatively correlated with lipid hydroperoxides level. In myoma tissue, we recorded a phase-related difference in lipid hydroperoxides level and activities of superoxide dismutase, glutathione peroxidase activities, and glutathione reductase. Negative correlation was observed between FSH and glutathione peroxidase. The results suggest that antioxidant status in patients with uterine leiomyoma is influenced by the changes in sex hormones during the menstrual cycle and in postmenopause, indicating a role of the observed relationship in the leiomyoma etiology.

Antioxidant status in blood of gynaecological patients: influence of diagnosis and reproductive factors

Cancer of the reproductive tract is an important cause of morbidity and mortality among women worldwide. In this study we evaluated the influence of diagnostic categories, age and reproductive factors on antioxidant enzymes and lipid hydroperoxides in the blood of gynaecological patients diagnosed with endometrial polyp, myoma, hyperplasia simplex, hyperplasia complex and endometrial adenocarcinoma. Multivariate regression analysis was used to assess the association of diagnosis, age, parity, abortions and abnormal uterine bleeding with the examined parameters. Diagnosis provided the best predictive model for superoxide dismutase, catalase and glutathione peroxidase activities, and also for the lipid hydroperoxide level. Abortions fitted the best predictive model for superoxide dismutase activity. A significant correlation was also found between the predictor variables themselves. This study showed that reproductive and other factors may be associated, at least partially, with antioxidant capacity and ability to defend against the oxidative damage in gynaecological patients with various diagnoses.

Antioxidant status and lipid peroxidation in the blood of breast cancer patients of different ages after chemotherapy with 5-fluorouracil, doxorubicin and cyclophosphamide

OBJECTIVES

Breast carcinoma is related to the increase of lipid peroxidation in plasma with concomitant decrease of antioxidant (AO) defense capacity in blood cells, which becomes more pronounced during aging of the patients. This work evaluated the potential age-related effect of chemotherapy with 5-fluorouracil, doxorubicin and cyclophosphamide (FAC) on the level of lipid hydroperoxides (LP), glutathione (GSH), AO enzyme activities of copper, zinc superoxide dismutase (CuZnSOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) in breast cancer patients. The level of CuZnSOD protein was assessed after the FAC therapy and radiotherapy of breast cancer.

DESIGN AND METHODS

AO parameters were measured in the blood of 58 breast cancer patients and 60 healthy age-matched healthy subjects by biochemical and Western blot analyses.

RESULTS

Increased oxidative stress (LP: p<0.05) and decreased AO enzyme activities (CuZnSOD: p<0.01, GPx: p<0.05, GR: p<0.01) and GSH level (p<0.01) in the blood of breast cancer patients in response to FAC chemotherapy seem not to be age-dependent. CuZnSOD enzyme expression decreased after the FAC chemotherapy (p<0.05), while it increased after the radiotherapy of breast cancer (p<0.05).

CONCLUSION

FAC chemotherapy and radiotherapy promote further oxidative shift, which potentiate already existing chronic oxidative stress linked to breast cancer. In these effects, impaired capacity for H(2)O(2) detoxification (CAT, GPX and GSH) seems to have major contribution.

Antioxidant enzymes and lipid peroxidation in endometrium of patients with polyps, myoma, hyperplasia and adenocarcinoma

BACKGROUND

Oxidative stress and impaired antioxidant system have been proposed as a potential factors involved in the pathophysiology of diverse disease states, including carcinogenesis. In this study, we explored the lipid peroxidation levels and antioxidant enzyme activities in women diagnosed with different forms of gynecological diseases in order to evaluate the antioxidant status in endometrium of such patients.

METHODS

Endometrial tissues of gynecological patients with different diagnoses were collected and subjected to assays for superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and lipid hydroperoxides.

RESULTS

Superoxide dismutase activity was significantly decreased (50% in average) in hyperplastic and adenocarcinoma patients. Activities of both glutathione peroxidase and glutathione reductase were increased 60% and 100% on average, in hyperplastic patients, while in adenocarcinoma patients only glutathione reductase activity was elevated 100%. Catalase activity was significantly decreased in adenocarcinoma patients (47%). Lipid hydroperoxides level was negatively correlated to superoxide dismutase and catalase activities, and positively correlated to glutathione peroxidase and glutathione reductase activities.

CONCLUSIONS

This study provided the first comparison of antioxidant status and lipid peroxidation in endometrial tissues of patients with polyps, myoma, hyperplasia and adenocarcinoma. The results showed that patients with premalignant (hyperplastic) and malignant (adenocarcinoma) lesions had enhanced lipid peroxidation and altered uterine antioxidant enzyme activities than patients with benign uterine diseases, polyps and myoma, although the extent of disturbance varied with the diagnosis. Further investigation is needed to clarify the mechanisms responsible for the observed alterations and whether lipid hydroperoxide levels and antioxidant enzyme activities in uterus of gynecological patients might be used as additional parameter in clinical evaluation of gynecological disorders.

Modulation of antioxidant enzyme activities by sexual steroid hormones

Taking into consideration the biological importance of interaction between antioxidant defense (AD) enzymes and sexual steroid hormones it was deemed important to compare our recent achievements in the field with the state of current knowledge. The main goal of the present review was to investigate the changes of AD enzyme activities: superoxide dismutases, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase in the brain of female and male rats depending on progesterone and estradiol. These ovarian steroids produce their effects by acting on numerous target tissues and organs, such as the reproductive organs, bone tissue and cartilage, peripheral blood vessels and the central nervous system (CNS). We have chosen it as a new parameter that might represent an important indicator of the changes within the CNS, bearing in mind the biological importance of the enzymes of the AD system. Our experimental results indicate that the AD enzyme activities in the brain tissue of female and male rats show a certain dependence on the concentration of progesterone and estradiol. The present review suggests that the modulation of the oxidative and antioxidative capacity by sexual steroid hormones is mediated through antioxidant metabolizing enzymes.

Neuroendocrine and oxidoreductive mechanisms of stress-induced cardiovascular diseases

The review concerns a number of basic molecular pathways that play a crucial role in perception, transmission, and modulation of the stress signals, and mediate the adaptation of the vital processes in the cardiovascular system (CVS). These highly complex systems for intracellular transfer of information include stress hormones and their receptors, stress-activated phosphoprotein kinases, stress-activated heat shock proteins, and antioxidant enzymes maintaining oxidoreductive homeostasis of the CVS. Failure to compensate for the deleterious effects of stress may result in the development of different pathophysiological states of the CVS, such as ischemia, hypertension, atherosclerosis and infarction. Stress-induced dysbalance in each of the CVS molecular signaling systems and their contribution to the CVS malfunctioning is reviewed. The general picture of the molecular mechanisms of the stress-induced pathophysiology in the CVS pointed out the importance of stress duration and intensity as etiological factors, and suggested that future studies should be complemented by the careful insights into the individual factors of susceptibility to stress, prophylactic effects of 'healthy' life styles and beneficial action of antioxidant-rich nutrition.

Regional differences in antioxidative response of rat brain after cranial irradiation

In order to examine if differences in activity and inducibility of antioxidative enzymes in rat cerebral cortex and hippocampus are underlying their different sensitivity to radiation, we exposed four-day-old female Wistar rats to cranial radiation of 3 Gy of gamma-rays. After isolation of hippocampus and cortex 1 h or 24 h following exposure, activities of copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD) and catalase (CAT) were measured and compared to unirradiated controls. MnSOD protein levels were determined by SDS-PAGE electrophoresis and Western blot analysis. Our results showed that CuZnSOD activity in hippocampus and cortex was significantly decreased 1 h and 24 h after irradiation with 3 Gy of gamma-rays. MnSOD activity in both brain regions was also decreased 1 h after irradiation. 24 h following exposure, manganese SOD activity in hippocampus almost achieved control values, while in cortex it significantly exceeded the activity of the relevant controls. CAT activity in hippocampus and cortex remained stable 1 h, as well as 24 h after irradiation with 3 Gy of gamma-rays. MnSOD protein level in hippocampus and cortex decreased 1 h after irradiation with 3 Gy of gamma-rays. 24 h after exposure, MnSOD protein level in cortex was similar to control values, while in hippocampus it was still significantly decreased. We have concluded that regional differences in MnSOD radioinducibility are regulated at the level of protein synthesis, and that they represent one of the main reasons for region-specific radiosensitivity of the brain.

Alterations in hippocampal antioxidant enzyme activities and sympatho-adrenomedullary system of rats in response to different stress models

The study deals with activity of three antioxidant enzymes, copper, zinc-superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), catalase (CAT) in hippocampus of rats, following the exposure to single chronic (individual housing or forced swimming) and acute (immobilization or cold) stress, as well as to combined chronic/acute stress. In addition, plasma noradrenaline (NA) and adrenaline (A) concentrations were measured in the same stress conditions, because their autooxidation can add to the oxidative stress. We observed that i) long-term social isolation and repeated forced swimming had minor effects on plasma catecholamines, but in the long-term pretreated groups, acute stressors caused profound elevation NA and A levels, ii) chronic stressors activate antioxidant enzymes, iii) acute stressors decrease catalase activity, their effects on CuZnSOD appear to be stressor-dependent, whereas MnSOD is not affected by acute stressors, and iv) pre-exposure to chronic stress affects the antioxidant-related effects of acute stressors, but this effect depends to a large extent on the type of the chronic stressor. Based on both metabolic and neuroendocrine data, long-term isolation appears to be a robust psychological stressor and to induce a "priming" effect specifically on the CuZnSOD and CAT activity.

The effect of ovarian hormones on antioxidant enzyme activities in the brain of male rats

The brain is widely responsive to gonadal hormones. The functional significance of ovarian hormones in the brain is evident from biochemical studies indicating that estradiol or progesterone treatment of testectomized rats produces changes of antioxidant enzyme activities. The effect of estradiol benzoate (EB) and progesterone (P) in the control of antioxidant (AO) enzyme activities was studied in the brain of adult male Wistar rats. The activities of catalase (CAT), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and glutathione reductase (GR) were measured in appropriate subcellular fractions, prepared from brains of animals belonging to various experimental groups. These groups were designed with the intention to follow changes in enzyme activities 2 h or 24 h after systemic administration of 5 microg EB or 2 mg P to testectomized (TX) animals. The obtained results show that both EB and P increase CAT activity, whereas EB decreases GSH-Px, GST and GR activities. These findings clearly show the modulatory role of EB and P in the control of enzymes responsible for the protection of rat nerve cells against oxidative damage caused by free oxygen radicals.

Effects of estradiol benzoate and progesterone on superoxide dismutase activity in the thymus of rats

The activity of mitochondrial superoxide dismutase (MnSOD) and cytosol superoxide dismutase (CuZnSOD) was measured in corresponding subcellular fractions prepared from the thymi of intact and chronically gonadectomized (GX) rats of both sexes, as well as of GX male and female rats injected subcutaneously with a single dose of 5 microg estradiol benzoate (EB) and/or 2 mg progesterone (P). Animals were sacrificed 2 h or 24 h following hormone treatment. In the females, the activity of MnSOD in the thymus was stable during the estrous cycle and did not change after ovariectomy. Treatment of GX females with estradiol benzoate resulted 2 h later in a significant elevation of MnSOD activity, whereas 24 h later the activity returned back to control values. On the other hand, treatment of GX females with progesterone had no effect on the MnSOD activity. However, combined hormone treatment, in which EB injection preceded progesterone injection by one hour, enhanced the effect on MnSOD activity similar to that of estradiol benzoate alone. The activity of CuZnSOD in cycling rats was increased in proestrus, whereas removal of the ovaries kept the values at low diestrus and estrus levels. Contrary to MnSOD, CuZnSOD activity did not change after EB treatment of GX females, while progesterone increased the enzyme activity at 2 h and 24 h after hormone treatment. However, combined EB+P treatment proved to be ineffective. In the males, neither MnSOD nor CuZnSOD activity was affected by the removal of testes or by progesterone treatment of GX animals. Only EB injection to GX rats significantly increased CuZnSOD activity 24 h later.

Role of antioxidant enzymes in radiosensitivity of human blood cells

The marked variability in radiation response among individuals of the same age group prompted us to investigate the role of antioxidative enzyme activity. Micronuclei (MN) and enzyme assays were performed on blood samples of healthy male volunteers. The procedure consisted of micronucleus analysis and measurement of the superoxide dismutase (SOD) activity in harvested blood samples irradiated in vitro with 2 Gy gamma-rays and in unirradiated control samples for each individual. We found that the yield of radiation-induced micronuclei was in the range of 112 to 378 micronuclei per 1000 binucleated cells. The activity of cytosol superoxide dismutase (CuZnSOD) was reduced, whereas the activity of manganese superoxide dismutase (MnSOD) was markedly elevated in the blood samples harvested in lymphocyte cultures after irradiation. The analysis of our results showed that MnSOD plays the most important role in radiation-induced cellular damage. The results of this investigation showed that measurement of micronuclei and the activities of SOD in harvested human blood cells can serve as a rapid predictive assay of radiosensitivity in a clinical setting.

Effects of olive oil on superoxide dismutase activity in the brain of newborn and young female rats

Changes in the activity of brain antioxidant superoxide dismutases (SOD) were followed in newborn and young female rats 8, 15, 30, 45, 60 and 75 days after birth treated with olive oil. In newborn rats, the content of brain cytosol SOD (CuZnSOD) and mitochondrial SOD (MnSOD) decreased after treatment with olive oil. However, in the brain of rats aged 8 days this effect was lost. The suppressive effect of olive oil on these enzymes reappeared again in 15-day-old rats. In rats aged one month, only the activity of CuZnSOD was reduced after olive oil treatment. In the brain of rats aged 45, 60 and 75 days, neither MnSOD nor CuZnSOD were affected by olive oil. The different effects of olive oil on the brain SOD, during ontogeny suggest that profound changes in the susceptibility of nervous tissue antioxidant enzymes to olive oil take place during sexual maturation.

Effects of progesterone and estradiol benzoate on glutathione dependent antioxidant enzyme activities in the brain of female rats

The activities of glutathione dependent antioxidant enzymes were measured in subcellular fractions of whole brain homogenates prepared from ovariectomized (OVX) female rats, untreated or treated 2 h or 24 h prior to sacrifice with a single dose of 2 mg progesterone (P) or 5 micrograms estradiol benzoate (EB). Glutathione peroxidase (GSH-Px) activity was not changed following systemic administration of EB, but P increased GSH-Px in the brain of OVX rats 24 h after the treatment. The activity of glutathione reductase (GR) was suppressed by EB short time, only 2 h following treatment, whereas P increased the enzyme activity 24 h after treatment. On the other hand, the activities of catalase (CAT) and glutathione-S-transferase (GST) were not changed following systemic administration of EB or P. The present work was carried out to study the involvement of ovarian steroids, especially P, in the control of GSH-Px and GR activities, and our results suggest that oxidative stress in the brain of female rats may be modulated by the level of progesterone.

Effects of estradiol benzoate and progesterone on superoxide dismutase activity in the rat liver

Activities of superoxide dismutases MnSOD and CuZnSOD were measured in appropriate subcellular fractions prepared from livers of intact and long-term gonadectomized (GX) rats of both sexes, and of GX female and male rats injected sc with a single dose of 5 micrograms estradiol benzoate (EB) or 2 mg progesterone (P). In female livers, MnSOD activity did not vary significantly during the estrous cycle, declined after gonadectomy in comparison to proestrus, and was steady in GX females treated with EB or P. The activity of CuZnSOD was lowered at proestrus and elevated after removal of the ovaries in comparison to proestrus value. EB suppressed, and P elevated CuZnSOD activity in GX females. In the liver of male rats, MnSOD was not affected by gonadectomy nor by EB and P treatments. CuZnSOD activity was reduced following orchiectomy and enhanced in GX males following treatment with P, while EB had no effect. These results suggest that P and EB modulate the activity of CuZnSOD and do not affect MnSOD in the rat liver. The modulatory effects are elicited by P in the males and by P and EB in the females.