Comparative toxicity of coal and coal ash: Assessing biological impacts and potential mechanisms through in vitro and in vivo testing.

BACKGROUND: Coal and coal ash present inorganic elements associated with negative impacts on environment and human health. The objective of this study was to compare the toxicity of coal and coal ash from a power plant, assess their inorganic components, and investigate the biological impacts and potential mechanisms through in vitro and in vivo testing. METHODS: Particle-Induced X-ray Emission method was used to quantify inorganic elements and the toxicity was evaluated in Caenorhabditis elegans and Daphnia magna in acute and chronic procedures. The genotoxic potential was assessed using alkaline and FPG-modified Comet assay in HepG2 cells and mutagenicity was evaluated using Salmonella/microsome assay in TA97a, TA100, and TA102 strains. RESULTS: Inorganic elements such as aluminum (Al) and chromium (Cr) were detected at higher concentrations in coal ash compared to coal. These elements were found to be associated with increased toxicity of coal ash in both Caenorhabditis elegans and Daphnia magna. Coal and coal ash did not induce gene mutations, but showed genotoxic effects in HepG2 cells, which were increased using the FPG enzyme, indicating DNA oxidative damage. CONCLUSIONS: The combined findings from bioassays using C. elegans and D. magna support the higher toxicity of coal ash, which can be attributed to its elevated levels of inorganic elements. The genotoxicity observed in HepG2 cells confirms these results. This study highlights the need for continuous monitoring in areas affected by environmental degradation caused by coal power plants. Additionally, the analysis reveals significantly higher concentrations of various inorganic elements in coal ash compared to coal, providing insight into the specific elemental composition contributing to its increased toxicity.

Melatonin prevents oxidative stress, inflammatory activity, and DNA damage in cirrhotic rats.

BACKGROUND: Cirrhosis is an important health problem characterized by a significant change in liver parenchyma. In animals, this can be reproduced by an experimental model of bile duct ligation (BDL). Melatonin (MLT) is a physiological hormone synthesized from serotonin that has been studied for its beneficial properties, including its antioxidant potential. AIM: To evaluate MLT's effects on oxidative stress, the inflammatory process, and DNA damage in an experimental model of secondary biliary cirrhosis. METHODS: Male Wistar rats were divided into 4 groups: Control (CO), CO + MLT, BDL, and BDL + MLT. MLT was administered (20 mg/kg) daily beginning on day 15 after biliary obstruction. On day 29 the animals were killed. Blood samples, liver tissue, and bone marrow were collected for further analysis. RESULTS: BDL caused changes in biochemical and histological parameters and markers of inflammatory process. Thiobarbituric acid (0.46 ± 0.01) reactive substance levels, superoxide dismutase activity (2.30 ± 0.07) and nitric oxide levels (2.48 ± 0.36) were significantly lower (P < 0.001) n the groups that received MLT. DNA damage was also lower (P < 0.001) in MLT-treated groups (171.6 ± 32.9) than the BDL-only group (295.5 ± 34.8). Tissue damage and the expression of nuclear factor kappa B, interleukin-1ß, Nrf2, NQO1 and Hsp70 were significantly lower in animals treated with MLT (P < 0.001). CONCLUSION: When administered to rats with BDL-induced secondary biliary cirrhosis, MLT effectively restored the evaluated parameters.

Nonclinical evaluation of IQG-607, an anti-tuberculosis candidate with potential use in combination drug therapy.

New effective compounds to treat tuberculosis are urgently needed. IQG-607 is an orally active anti-tuberculosis drug candidate, with promising preliminary safety profile and anti-mycobacterial activity in both in vitro and in vivo models of tuberculosis infection. Here, we evaluated the mutagenic and genotoxic effects of IQG-607, and its interactions with CYP450 isoforms. Moreover, we describe for the first time a combination study of IQG-607 in Mycobacterium tuberculosis-infected mice. Importantly, IQG-607 had additive effects when combined with the first-line anti-tuberculosis drugs rifampin and pyrazinamide in mice. IQG-607 presented weak to moderate inhibitory potential against CYP450 isoforms 3A4, 1A2, 2C9, 2C19, 2D6, and 2E1. The Salmonella mutagenicity test revealed that IQG-607 induced base pair substitution mutations in the strains TA100 and TA1535. However, in the presence of human metabolic S9 fraction, no mutagenic effect was detected in any strain. Additionally, IQG-607 did not increase micronucleus frequencies in mice, at any dose tested, 25, 100, or 250 mg/kg. The favorable activity in combination with first-line drugs and mild to moderate toxic events described in this study suggest that IQG-607 represents a candidate for clinical development.

Effect of therapeutic ultrasound on the quadriceps muscle injury in rats - evaluation of oxidative stress and inflammatory process.

Muscle injuries are frequent, both in sports and work, and may be caused by stretching, distension, repetitive effort or bruising. Such lesions can lead to the generation of free radicals, triggering oxidative stress and the release of some inflammatory mediators. Therapeutic ultrasound (UST) is one of the most used electrotherapy resources in the physiotherapist's clinical practice. Our aim was to evaluate the use of therapeutic ultrasound on oxidative stress and inflammatory process in an experimental model of single quadriceps muscle injury in Wistar rats. We used a total of 28 male rats, weighing between 250-300 grams, randomly divided into four groups. In the right quadriceps, a simple impact of contusion was induced by means of a press. The animals were submitted to a daily UST treatment for a total of seven consecutive applications for three minutes each, that started 24 hours after the trauma induction. The results in the Trauma + Therapeutic ultrasound group at TBARS levels and in the enzymatic activity of SOD and GPx presented a significant difference. In the histological analysis of the Trauma + Therapeutic ultrasound group presented a reorganization of the fiber's structure and a reduction of the presence of inflammatory infiltrate. In the results of the immunohistochemistry of iNOS, TNF-α and NF-κB in muscle tissue, we observed that the group treated with ultrasound showed a reduction in the expression of the proteins. The use of UST was effective in protecting muscle tissue from oxidative stress, inflammatory process and in the rearrangement of muscle fibers.

Pre-clinical evaluation of quinoxaline-derived chalcones in tuberculosis.

New effective compounds for tuberculosis treatment are needed. This study evaluated the effects of a series of quinoxaline-derived chalcones against laboratorial strains and clinical isolates of M. tuberculosis. Six molecules, namely N5, N9, N10, N15, N16, and N23 inhibited the growth of the M. tuberculosis H37Rv laboratorial strain. The three compounds (N9, N15 and N23) with the lowest MIC values were further tested against clinical isolates and laboratory strains with mutations in katG or inhA genes. From these data, N9 was selected as the lead compound for further investigation. Importantly, this chalcone displayed a synergistic effect when combined with moxifloxacin. Noteworthy, the anti-tubercular effects of N9 did not rely on inhibition of mycolic acids synthesis, circumventing important mechanisms of resistance. Interactions with cytochrome P450 isoforms and toxic effects were assessed in silico and in vitro. The chalcone N9 was not predicted to elicit any mutagenic, genotoxic, irritant, or reproductive effects, according to in silico analysis. Additionally, N9 did not cause mutagenicity or genotoxicity, as revealed by Salmonella/microsome and alkaline comet assays, respectively. Moreover, N9 did not inhibit the cytochrome P450 isoforms CYP3A4/5, CYP2C9, and CYP2C19. N9 can be considered a potential lead molecule for development of a new anti-tubercular therapeutic agent.

A 28-day Sub-acute Genotoxic and Behavioural Assessment of Garcinielliptone FC.

Garcinielliptone FC (GFC) is a polyisoprenylated benzophenone isolated from Platonia insignis Mart (Clusiaceae) with promising anticonvulsant properties. However, its safe use and other effects on the central nervous system require assessment. This study assessed the toxicological effects of GFC using the comet assay and the micronucleus test in mice treated for 28 days. A behavioural model was employed to detect possible injuries on the central nervous system. Mice treated with GFC (2, 10 and 20 mg/kg; i.p.) daily for 28 days were submitted to rotarod test, open-field test and tail suspension test (TST). After the behaviour tasks, biological samples were assessed to evaluate genotoxic and mutagenic effects using the comet assay and the micronucleus test. Garcinielliptone FC did not impair the performance of the animals in the rotarod and open-field tests, with no antidepressant-like effect in TST. No genotoxic effects in blood and cerebral cortex were observable in the comet assay; however, there was a significant increase in index and frequency of damage in liver after treatment with GFC 20 mg/kg. Garcinielliptone FC did not increase micronucleus frequency in bone marrow. At the tested doses, GFC was not toxic to the CNS and did not induce genotoxic damage to blood or bone narrow cells. DNA damage to liver tissue was caused only by the highest dose, although no mutagenic potential was observed.

Evaluation of Toxicological Effects of an Aqueous Extract of Shells from the Pecan Nut Carya illinoinensis (Wangenh.) K. Koch and the Possible Association with Its Inorganic Constituents and Major Phenolic Compounds.

Background. Industrial processing of the pecan nut Carya illinoinensis K. Koch generated a large amount of shells, which have been used to prepare nutritional supplements and medicinal products; however, the safe use of shells requires assessment. This study evaluated the toxic, genotoxic, and mutagenic effects of pecan shell aqueous extract (PSAE) and the possible contribution of phenolic compounds, ellagic and gallic acids, and inorganic elements present in PSAE to induce toxicity. Results. Levels of inorganic elements like K, P, Cl, and Rb quantified using the Particle-Induced X-Ray Emission method were higher in PSAE than in pecan shells, while Mg and Mn levels were higher in shells. Mice showed neurobehavioral toxicity when given high PSAE doses (200-2,000 mg kg(-1)). The LD50 was 1,166.3 mg kg(-1). However, PSAE (50-200 mg·kg(-1)) and the phenolic compounds (10-100 mg·kg(-1)) did not induce DNA damage or mutagenicity evaluated using the comet assay and micronucleus test. Treatment with ellagic acid (10-100 mg·kg(-1)) decreased triglyceride and glucose levels, while treatments with PSAE and gallic acid had no effect. Conclusion. Pecan shell toxicity might be associated with high concentrations of inorganic elements such as Mn, Al, Cu, and Fe acting on the central nervous system, besides phytochemical components, suggesting that the definition of the safe dose should take into account the consumption of micronutrients.

Determination of the main impurities formed after acid hydrolysis of soybean extracts and the in vitro mutagenicity and genotoxicity studies of 5-ethoxymethyl-2-furfural.

Soybean acid hydrolyzed extracts are raw-materials widely used for manufacturing of pharmaceuticals and cosmetics products due to their high content of isoflavone aglycones. In the present study, the main sugar degradation products 5-hydroxymethyl-2-furfural (HMF) and 5-ethoxymethyl-2-furfural (EMF) were quantitatively determined after acid hydrolysis of extracts from different soybean cultivars by a validated liquid chromatography method. The furanic compounds determined in samples cover the range of 0.16-0.21mg/mL and 0.22-0.33mg/mL for HMF and EMF, respectively. Complementarily, due to the scarce literature regarding the EMF toxicology, this study also assessed the EMF mutagenicity by the Salmonella/microsome test and genotoxicity by the comet assay. The results revealed that EMF did not show mutagenicity at the range of 50-5000µg/plate in S. typhimurium strains TA98, TA97a, TA100, TA102 and TA1535, but induced DNA damage in HepG2 cells at non-cytotoxic doses of 0.1-1.3mg/mL, mainly by oxidative stress mechanisms. Based on literature of HMF genotoxicity, and considering the EMF genotoxicity results herein shown, purification procedures to remove these impurities from extracts are recommended during healthcare products development to ensure the security of the products.

Chemical and toxicological effects of medicinal Baccharis trimera extract from coal burning area.

The entire process of power generation, extraction, processing and use of coal strongly impact water resources, soil, air quality and biota leads to changes in the fauna and flora. Pollutants generated by coal burning have been contaminating plants that grow in area impacted by airborne pollution with high metal contents. Baccharis trimera is popularly consumed as tea, and is widely developed in Candiota (Brazil), one of the most important coal burning regions of the Brazil. This study aims to investigate the phytochemical profile, in vivo genotoxic and mutagenic potential of extracts of B. trimera collected from an exposed region to pollutants generated by coal burning (Candiota City) and other unexposed region (Bagé City), using the Comet assay and micronucleus test in mice and the Salmonella/microsome short-term assay. The HPLC analyses indicated higher levels of flavonoids and phenolic acids for B. trimera aqueous extract from Bagé and absence of polycyclic aromatic hydrocarbons for both extracts. The presence of toxic elements such as cobalt, nickel and manganese was statistically superior in the extract from Candiota. For the Comet assay and micronucleus test, the mice were treated with Candiota and Bagé B. trimera aqueous extracts (500-2000 mg/kg). Significant genotoxicity was observed at higher doses treated with B. trimera aqueous extract from Candiota in liver and peripheral blood cells. Micronuclei were not observed but the results of the Salmonella/microsome short-term assay showed a significant increase in TA98 revertants for B. trimera aqueous extract from Candiota. The extract of B. trimera from Candiota bioacumulated higher levels of trace elements which were associated with the genotoxic effects detected in liver and peripheral blood cells.

The Antidiabetic and Antihypercholesterolemic Effects of an Aqueous Extract from Pecan Shells in Wistar Rats.

Pecan shell decoction has been used to treat diabetes and obesity-related diseases. In this study, the effects of a pecan shell aqueous extract (PSAE) were evaluated in diabetic and hypercholesterolemic Wistar rats, analyzing clinical signs and biochemical as well as genotoxic and mutagenic parameters, to assess its safe use and efficacy. Diabetes mellitus and hypercholesterolemia were induced with streptozotocin (STZ) and tyloxapol, respectively. Animals were orally administered PSAE (100 mg/kg body weight, b.w.) for 28 days. Biochemical analyses and genotoxicity were evaluated in blood samples and mutagenicity was evaluated in bone marrow. PSAE treatment decreased the blood glucose level and stabilized clinical signs of diabetes in diabetic rats. PSAE diminished the increase in total cholesterol and triglyceride levels in hypercholesterolemic rats. The urea levels were higher in diabetic rats than in treated ones; however, creatinine values were the same in all groups. Elevated transaminase levels were suggestive of liver injuries in diabetic rats, and were not altered by PSAE treatment. PSAE did not show genotoxic or mutagenic activities in diabetic and hypercholesterolemic rats, indicating its safe use at 100 mg/kg b.w. not only in healthy rats but also in rats with induced metabolic alterations. The findings on PSAE's efficacy may indicate that its successful and popular use is in accordance with our results. Thus, PSAE might be a potential candidate for medical purposes as a complementary treatment of diabetes and hypercholesterolemia.

Neurotoxicological profile assessment of lobeline after acute treatment in mice.

Lobeline is a natural alkaloid with high affinity for nicotinic acetylcholine receptors, and it is a promising candidate for addiction treatment in human beings. This work evaluated the toxicological profile of lobeline with different behavioural models and investigated its effect on DNA damage (comet assay and micronucleus test) in mice. Acute administration of lobeline (5 or 10 mg/kg; i.p.) did not impair the parameters measured in the habituation and inhibitory avoidance test, suggesting that it has no effect on memory acquisition in these tasks. Lobeline did not affect the number or the latency to the first head-dip in the hole board test, indicating that it was not anxiolytic/anxiogenic in this model. No genotoxic effects were observed in blood, liver and brain tissues collected 24 hr after the single injection of lobeline (both doses). There was no increase in micronucleus frequency in mice treated with lobeline, indicating the absence of toxicity in bone marrow of the animals. Therefore, the acute treatment with high doses of lobeline did not impair the behavioural parameters measured in this work. Additionally, the drug was not able to produce DNA damage.

Neuropharmacological and genotoxic evaluation of ethanol extract from Erythrina falcata leaves, a plant used in Brazilian folk medicine

The aim of the present study was to determine neurobehavioral and genotoxic activities of ethanol extract of Erythrina falcata Benth., Fabaceae, leaves on rats. Animals were treated with ethanol extract of E. falcata (100, 300 or 500 mg/kg; i.p.) and the open field and elevated plus-maze tasks were used as behavioral models to investigate a possible effect on the locomotor and exploratory activity and anxiety, respectively. Genotoxic effect was investigated using the Comet assay. Ethanol extract of E. falcata leaves decreased the number of crossings and rearings in the open field task and increased the latency to start locomotion, though it was not able to affect habituation to apparatus measured 24h after the first session. Behavioral parameters in the plus-maze test were not affected by E. falcata. Ethanol extract did not increase damage index and damage frequency in blood or brain, indicating no genotoxic effect. The results suggest that ethanol extract of E. falcata leaves was able to affect locomotion, exploration, and motivation of animals without anxiolytic/anxiogenic effect, indicating a possible depressant action on the central nervous system. Furthermore, the lack of DNA damage in brain is an indicative that ethanol extract of E. falcata leaves may not induce neurotoxic effects.

In vivo genotoxicity evaluation of an artichoke (Cynara scolymus L.) aqueous extract.

UNLABELLED: The Cynara scolymus (artichoke) is widely consumed as tea or food and shows important therapeutic properties. However, few studies have assessed the possible toxic effects of artichoke extracts. This study evaluates genotoxic and mutagenic activities of artichoke leaf aqueous extract in mice using the comet assay and the micronucleus test. Leaf extracts were given by gavage (500 mg/kg, 1000 mg/kg, and 2000 mg/kg) for 3 consecutive days. Extract composition was investigated using phytochemical screening and high-performance liquid chromatography (HPLC). In addition, antioxidant capacity was analyzed through the diphenyl-picrylhydrazyl (DPPH) and xanthine oxidase assay. Phytochemical screening detected the presence of phenolic compounds, flavonoids, and saponins. HPLC analyses indicated the presence of chlorogenic acid, caffeic acid, isoquercetrin, and rutin. Extracts showed a dose-dependent free radical scavenging effect of DPPH and an inhibitory effect of xanthine oxidase. The genotoxic results showed that leaf extracts did not increase micronuclei in peripheral blood cells. Compared to the control group, a significant increase in comet assay values was observed only in bone marrow of group treated with 2000 mg/kg, the highest dose tested, indicating that artichoke tea should be consumed with moderation. PRACTICAL APPLICATION: This is the first report of in vivo mutagenic and genotoxic evaluation with C. scolymus. The present study revealed leaf aqueous extract from artichoke shows lack of mutagenicity in vivo, and low genotoxicity and antioxidant activity; indicating that artichoke tea should be consumed with moderation.

Rosmarinic acid as a protective agent against genotoxicity of ethanol in mice.

The aim of the present work was to study the protective effects of rosmarinic acid against ethanol-induced DNA damage in mice. The antigenotoxic capacity of rosmarinic acid (100 mg/kg) was tested using pre-, co- and post-treatment with ethanol (5 g/kg). Peripheral blood (1 and 24 h) and brain cells (24 h) were evaluated using the comet assay and bone marrow was analyzed using the micronucleus assay (24 h). The results were compared to data of TBARS, enzymes with antioxidant activity, and DCFH-DA test. Peripheral blood and brain cells show that mean damage index (DI) and damage frequency (DF) values of ethanol with pre-treatment with rosmarinic acid group were significantly lower than in the ethanol group. In brain cells all different treatments with ethanol and rosmarinic acid showed significant decrease in DI and DF mean values when compared to ethanol group and negative control. No significant differences were observed in micronucleus frequency, activity of antioxidant enzymes and TBARS between groups. The DCFH-DA test show a reduction of 18% of fluorescence intensity when compare with ethanol group. The results show that rosmarinic acid could decrease the levels of DNA damage induced by ethanol, for both tissues and treatment periods.

Hepatic oxidative stress in an animal model of sleep apnoea: effects of different duration of exposure.

BACKGROUND: Repeated apnoea events cause intermittent hypoxia (IH), which alters the function of various systems and produces free radicals and oxidative stress. METHODS: We investigated hepatic oxidative stress in adult mice subjected to intermittent hypoxia, simulating sleep apnoea. Three groups were submitted to 21 days of IH (IH-21), 35 days of IH (IH-35), or 35 days of sham IH. We assessed the oxidative damage to lipids by TBARS and to DNA by comet assay; hepatic tissue inflammation was assessed in HE-stained slides. Antioxidants were gauged by catalase, superoxide dismutase, glutathione peroxidase activity and by total glutathione. RESULTS: After IH-21, no significant change was observed in hepatic oxidative stress. After IH-35, significant oxidative stress, lipid peroxidation, DNA damage and reduction of endogenous antioxidants were detected. CONCLUSIONS: In an animal model of sleep apnoea, intermittent hypoxia causes liver damage due to oxidative stress after 35 days, but not after 21 days.

Genotoxic and antigenotoxic properties of Baccharis trimera in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Baccharis trimera (Less.) (Asteraceae) is a native plant from Brazil. Also known as "carqueja", it is popularly used to treat liver diseases, diabetes, as well as digestive disorders, mainly by women with lower socioeconomic status. AIM OF THE STUDY: The aim of the present study was to investigate the in vivo genotoxic/antigenotoxic and mutagenic potential of this plant, using the comet and the micronucleus assays. MATERIAL AND METHODS: Female adult mice were treated with 500, 1000 or 2000 mg/kg of B. trimera aqueous extract (Bt-AE) by gavage for three consecutive days. RESULTS: Independently of the dose, no genotoxic effect was observed in blood and liver samples analyzed by the comet assay. Conversely, B. trimera showed an antigenotoxic effect in blood from treated mice, thus protecting cells against oxidative DNA damage induced by the ex vivo treatment with hydrogen peroxide. In addition, Bt-AE showed in vitro antioxidant activity, assessed by DPPH and xanthine oxidase assays, suggesting that the observed antigenotoxic effects might be related to its antioxidant properties. CONCLUSIONS: However, the extract increased the frequency of micronucleus in bone marrow of treated mice, indicating a chromosomal mutagenic activity. Thus, medicines prepared from this plant should be used with caution, although the results also suggest antigenotoxic effects for B. trimera aqueous extract.

Mutagenic and genotoxic effects of Baccharis dracunculifolia (D.C.).

Baccharis dracunculifolia (D.C.) (Asteraceae), a native plant to Brazil known as "vassourinha" or "alecrim-do-campo", is the most important botanical source of a Brazilian propolis called green propolis. The leaf extracts of this plant have been used to treat liver and digestive disorders. It has been recognized that green propolis can induce mutagenic effects at high doses, but no study reporting possible mutagenic effects by Baccharis dracunculifolia extracts in the maximum tolerated dose has been conducted. The aim of the present study was to investigate the genotoxic and mutagenic effects of this plant in vivo. Adult CF-1 mice were treated with 0.5g/kg, 1.0g/kg or 2.0g/kg of an aqueous extract of Baccharis dracunculifolia by gavage for 3 consecutive days. Blood and liver samples were collected to detect DNA damage using the comet assay, while bone marrow samples were used to assess chromosome mutations by the micronucleus test. The extract increased the DNA damage in blood and liver tissues and the frequency of micronucleus in bone marrow. These findings suggest genotoxic and mutagenic effects of Baccharis dracunculifolia comparable to green propolis in mice.

Antimutagenic activity of cashew apple (Anacardium occidentale Sapindales, Anacardiaceae) fresh juice and processed juice (cajuína) against methyl methanesulfonate, 4-nitroquinoline N-oxide and benzo[a]pyrene

Cashew apple juice (CAJ), produced from the native Brazilian cashew tree (Anacardium occidentale), and has been reported to have antibacterial, antifungal, antitumor, antioxidant and antimutagenic properties. Both the fresh unprocessed juice and the processed juice (cajuína in Portuguese) has been shown to consist of a complex mixture containing high concentrations of anacardic and ascorbic acids plus several carotenoids, phenolic compounds and metals. We assessed both types of juice for their antimutagenic properties against the direct mutagens methyl methanesulfonate (MMS) and 4-nitroquinoline-N-oxide (4-NQO) and the indirect mutagen benzo[a]pyrene (BaP) using pre-treatment, co-treatment and post-treatment assays with Salmonella typhimurium strains TA100, TA102, and TA97a. In pre-treatment experiments with strains TA100 and TA102 the fresh juice showed high antimutagenic activity against MMS but, conversely, co-treatment with both juices enhanced MMS mutagenicity and there was an indication of toxicity in the post-treatment regime. In pre-, co-, and post-treatments with TA97a as test strain, antimutagenic effects were also observed against 4-NQO and BaP. These results suggest that both fresh and processed CAJ can protect the cells against mutagenesis induced by direct and indirect mutagens.

Oxidative damage in brains of mice treated with apomorphine and its oxidized derivative.

Increasing evidence suggests that some of the neurobiological and neurotoxic actions of apomorphine and other dopamine receptor agonists might be mediated by their oxidation derivatives. The aim of the present study was to evaluate the effects of apomorphine and its oxidation derivative, 8-oxo-apomorphine-semiquinone (8-OASQ), on oxidative stress parameters and antioxidant enzyme activity. Adult male CF-1 mice were treated with a systemic injection of apomorphine (0.4, 4.0 or 40.0 mg/kg) or 8-OASQ (0.4, 4.0 or 40.0 mg/kg). Animals were sacrificed by decapitation 24 h after treatment, and the forebrains were collected for analysis of thiobarbituric acid reactive species, protein carbonyls, the total radical-trapping antioxidant parameter, catalase and superoxide dismutase. These treatments did not induce lipid peroxidation at any dose tested. In contrast, apomorphine induced an increase in protein carbonylation and a decrease in total radical-trapping antioxidant parameter at all doses tested. 8-OASQ induced an increase in protein carbonylation and a decrease in total radical-trapping antioxidant parameter only at the higher dose tested. All apomorphine doses tested induced an increase in catalase, but not superoxide dismutase activities. In contrast, 8-OASQ induced a dose-dependent increase in CAT activity. The results suggest that apomorphine and its oxidation product, 8-OASQ, induce differential effects on CNS oxidative parameters.

Differential mutagenic, antimutagenic and cytotoxic responses induced by apomorphine and its oxidation product, 8-oxo-apomorphine-semiquinone, in bacteria and yeast.

Apomorphine (APO) is considered to be a classical mixed type dopamine D(1) and D(2) receptor agonist. It has been used in the therapy of Parkinson's disease and, more recently, for the treatment of erectile dysfunction. Like other catechols (e.g. dopamine), APO easily autoxidizes, producing quinone and semiquinone derivatives that may lead to the formation of reactive oxygen species and induce neurotoxicity. We assayed mutagenicity, antimutagenicity, and cytotoxicity of these compounds by means of the Salmonella/microsome assay, WP2 Mutoxitest and sensitivity assay in Saccharomyces cerevisiae yeast strains lacking antioxidant defenses. In the absence of S9 mix both compounds Apomorphine and its oxidation derivative, 8-oxo-apomorphine-semiquinone (8-OASQ), both at doses ranging from 20 to 80 microg per plate, induced frameshift mutations in TA98 and TA97 S. typhimurium strains, with 8-OASQ being up to two times more mutagenic. However, for strains which detect oxidative mutagens, 8-OASQ acted as a mutagen while APO was an antimutagen, inhibiting H(2)O(2) and t-BOOH-induced mutagenicity in TA102 S. typhimurium and WP2-derived E. coli strains. The S9 mix inhibited all mutagenic effects, probably either by conjugation of APO and 8-OASQ to proteins or by quenching reactive oxygen species. In sensitivity assays with S. cerevisiae, APO was only clearly cytotoxic to some strains at higher doses (200 and 400 microg/ml), whereas 8-OASQ dose-dependently sensitized all the strains, mainly the mutants lacking catalase (deltactt1), superoxide dismutase (deltasod1) and Yap1 transcription factor (deltayap1), suggesting that 8-OASQ cytotoxicity towards S. cerevisiae results from its pro-oxidant properties. APO also tended to protect S. cerevisiae strains against oxidative damage induced by high concentrations of H(2)O(2) and t-BOOH, while 8-OASQ enhanced pro-oxidant effects and induced adaptation responses to these agents. These results suggest that the 8-OASQ oxidation product of APO might induce cytotoxic and genotoxic effects.