Cytogenetic changes in oral mucosa cells from individuals submitted to oral human immunodeficiency virus pre-exposure prophylaxis use.

OBJECTIVE: The objective of this study was to evaluate cytogenetic changes in individuals submitted to oral human immunodeficiency virus pre-exposure prophylaxis use through the micronucleus test in oral mucosa. METHODS: This study consisted of 37 individuals, of whom 17 comprised the pre-exposure prophylaxis group and 20 comprised the control group. A total of 2,000 cells per slide were analyzed for the determination of micronuclei, binucleation, nuclear buds, and cytotoxicity parameters: pyknosis, karyolysis, and karyorrhexis (KR), in a double-blind manner. The repair index was also evaluated in this setting. RESULTS: In the mutagenicity parameters, the pre-exposure prophylaxis group showed increased frequencies of micronuclei (p=0.0001), binucleation (p=0.001), and nuclear buds (p=0.07). Regarding the cytotoxicity parameters, there was an increase with a statistical difference (p≤0.05) in the karyorrhexis frequency (p=0.001). Additionally, the repair system efficiency decreased in the pre-exposure prophylaxis group. CONCLUSION: These results indicate that individuals undergoing pre-exposure prophylaxis use have geno- and cytotoxicity in oral mucosal cells.

Micronuclei in embryos of eight seabird species in northwestern Mexico: A biomarker of exposure to coastal pollution?

The micronucleus (MN) test may be used to evaluate genome instability in birds and the potential of different species to function as biomarkers of genotoxicity. However, little is known regarding genome instability in seabird embryos or the instability present among embryonic development stages. Therefore, the present study aimed to describe the frequencies of micronucleated erythrocytes (MNE) and micronucleated polychromatic erythrocytes (MNPCE) in blood samples collected from the embryos of eight seabird species nesting on the coast of Sinaloa, Mexico. An additional description of blood cell maturation along with embryo development during incubation was conducted based on the proportion of polychromatic erythrocytes (PCE), and the potential relationships between metals (Hg and Cd concentrations in egg content) and the MN frequencies in embryo blood were evaluated. The PCE proportion appears to decline as incubation advances (initial stage > intermediate stage > advanced stage), and the values varied between species (Suliformes/Pelecaniformes < Charadriiformes: Laridae), which may be related to differences among incubation periods and reproductive strategies. Interspecific variation in the MNPCE frequency was found in embryos showing advanced development, which could be related to both variations in life-history traits and ecological factors and not Hg or Cd exposure. The genomic instability values in this study are the first to be reported for embryos of seabird species nesting in a subtropical coastal region.

Resveratrol-Tempeh reduce micronucleus frequencies bone marrow cells and stimulate osteocyte proliferation in aluminum chloride-induced mice.

Aluminum (Al) is widely used for water purification, cooking pots, cosmetic and pharmaceutical preparations, toothpaste tubes, and food processing industries. Although the transport in the digestive tract is very poor but if the load is high, it can be absorbed and accumulated. About 50-70% of Al accumulates in the bones and can have an impact on human health. Resveratrol (RES), isolated from tempeh as an Indonesian food ingredient, can increase cell viability and has promising cytoprotective effects. RES has the capacity to interact with oxidative stress, so it has the potential as a therapy in bone repair. Therefore, this study aimed to evaluate the effect of RES on the number of osteocytes and bone marrow cells in Al-induced mice. Swiss Webster mice were divided into four groups: (1) untreated groups, (2) AlCl3-treated groups, (3) Al+Res5 treated groups, and (4) Al+Res10 treated groups. Al dose 200 mg/kg body weight was administered intraperitoneally. RES was given one hour after administration of Al, with doses of 5 and 10 mg/kg Body Weight. Al and RES administration is carried out for one month. All mice were sacrificed, and mouse bones were isolated for histological preparations and a half for genotoxic assays. Bone marrow cells were collected and stained with My Grunwald. The number of micronuclei polychromatic erythrocytes (MNPCE) was examined in 1,000 PCEs per animal. The number of PCEs is counted by at least 200 erythrocytes (PCE + NCE) per animal. The results showed that the administration of Al significantly increased the number of micronuclei (MN) but after administration of RES at doses of 5 and 10 mg/kg Body Weight significantly reduced the number of MN in bone marrow cells. A dose of RES 10 mg/kg BW stimulates proliferation and increases the number of osteocytes in bone significantly. It can be concluded that Al can cause genotoxicity in bone marrow cells and RES is anti-genotoxic and can stimulate osteocyte proliferation.

Factors Affecting the Nuclei in Newborn and Children.

It is known that children are more sensitive to the effects of medical treatments and environment than adults. Today there is limited information regarding the differences in genotoxic effects in children. The micronucleus assay is a method that is used to monitor genotoxicity, and it was validated several years before. Today there is international interest for exfoliated buccal cells. Most of the micronuclei studies in children have been performed with the analyses of lymphocytes. However, there is vast interest in using exfoliated cells from the oral cavity. The reason is that other type of cells are acquired non-invasively, this is an important issue in paediatric cohorts. Unfortunately a limitation of measuring micronuclei frequency is that it has been observed to be low in newborns and on the other hand there are a large number of patients and cell sample counts. It has been observed that radiation exposure and environmental pollutants increase the micronuclei frequency in newborn and children. Regarding the medical treatments, there is little data and several studies are needed to optimise the doses. There is the need to observe if there is a relationship between micronuclei in lymphocytes and exfoliated cells and to identify the baseline of the micronuclei levels. Moreover, we evaluate the changes in response to the toxic agents. Prospective cohorts studies will clarify the predictive value of micronuclei for cancer and chronic diseases for both children and adults. Novel molecular technologies will assist in the elucidation of different biological pathways and molecular mechanisms connected with the micronulcei levels in newborn and children.

Molecular Consequences of Depression Treatment: A Potential In Vitro Mechanism for Antidepressants-Induced Reprotoxic Side Effects.

The incidence of depression among humans is growing worldwide, and so is the use of antidepressants. However, our fundamental understanding regarding the mechanisms by which these drugs function and their off-target effects against human sexuality remains poorly defined. The present study aimed to determine their differential toxicity on mouse spermatogenic cells and provide mechanistic data of cell-specific response to antidepressant and neuroleptic drug treatment. To directly test reprotoxicity, the spermatogenic cells (GC-1 spg and GC-2 spd cells) were incubated for 48 and 96 h with amitriptyline (hydrochloride) (AMI), escitalopram (ESC), fluoxetine (hydrochloride) (FLU), imipramine (hydrochloride) (IMI), mirtazapine (MIR), olanzapine (OLZ), reboxetine (mesylate) (REB), and venlafaxine (hydrochloride) (VEN), and several cellular and biochemical features were assessed. Obtained results reveal that all investigated substances showed considerable reprotoxic potency leading to micronuclei formation, which, in turn, resulted in upregulation of telomeric binding factor (TRF1/TRF2) protein expression. The TRF-based response was strictly dependent on p53/p21 signaling and was followed by irreversible G2/M cell cycle arrest and finally initiation of apoptotic cell death. In conclusion, our findings suggest that antidepressants promote a telomere-focused DNA damage response in germ cell lines, which broadens the established view of antidepressants' and neuroleptic drugs' toxicity and points to the need for further research in this topic with the use of in vivo models and human samples.

Cytogenetic Consequences of Food Industry Workers Occupationally Exposed to Cooking Oil Fumes (COFs).

BACKGROUND: Cooking oil fumes (COFs) with smoking habits is a substantial risk that aggravates genetic modifications. The current study was to estimate the biological markers of genetic toxicity counting Micronucleus changes (MN), Chromosome Aberrations (CA) and DNA modifications among COFs exposures and control subjects inherent from South India. MATERIALS AND METHODS: Present analysis comprised 212 COFs with tobacco users and equivalent number of control subjects. RESULTS: High frequency of CA (Chromatid type: and chromosome type) were identified in group II experimental subjects also high amount of MN and DNA damage frequency were significantly (p < 0.05) in both subjects (experimental smokers and non-smokers). Present analysis was observed absence of consciousness among the COFs exposures about the destructive level of health effects of tobacco habits in working environment. CONCLUSION: COFs exposed workers with tobacco induce the significant alteration in chromosomal level. Furthermore, a high level of rate of genetic diseases (spontaneous abortion) were identified in the experimental subjects. This finding will be helpful for preventive measures of COFs exposed workers and supportive for further molecular analysis.

Oxidative Stress, Mutations and Chromosomal Aberrations Induced by In Vitro and In Vivo Exposure to Furan.

Furan is a volatile compound that is formed in foods during thermal processing. It is classified as a possible human carcinogen by international authorities based on sufficient evidence of carcinogenicity from studies in experimental animals. Although a vast number of studies both in vitro and in vivo have been performed to investigate furan genotoxicity, the results are inconsistent, and its carcinogenic mode of action remains to be clarified. Here, we address the mutagenic and clastogenic activity of furan and its prime reactive metabolite cis-2 butene-1,4-dial (BDA) in mammalian cells in culture and in mouse animal models in a search for DNA lesions responsible of these effects. To this aim, Fanconi anemia-derived human cell lines defective in the repair of DNA inter-strand crosslinks (ICLs) and Ogg1-/- mice defective in the removal of 8-hydroxyguanine from DNA, were used. We show that both furan and BDA present a weak (if any) mutagenic activity but are clear inducers of clastogenic damage. ICLs are strongly indicated as key lesions for chromosomal damage whereas oxidized base lesions are unlikely to play a critical role.

Global and gene-specific promoter methylation, and micronuclei induction in lead-exposed workers: A cross-sectional study.

Perturbation of epigenetic regulation is a well-established mechanism for cancer but its role for lead (Pb)-associated toxicity has not been adequately investigated. We aimed to investigate whether occupational Pb exposure is associated with micronuclei (MN) frequency and to further explored the mediating roles of epigenetic gene regulation. All the Pb-exposed workers recruited from a Chinese acid battery factory, blood lead levels (BLLs) and MN frequency in lymphocytes were measured. In addition, methylation levels of seven genes (Line-1, RASSF1A, RUNX3, p16, CYP26C1, hMLH1, p15) were examined among 230 workers. Robust Poisson regression model was used to investigate the association between BLLs and MN frequency. Mediation analysis was used to explore the mediating role of specific DNA methylation. Among total 677 participants, 71% were male, median BLLs was 229.1 µg/L (P25  = 155.5, P75  = 319.3; ranged from 8.9 to 647.7 µg/L), mean MN frequency was 2.5‰ (SD = 1.8‰; ranged from 0 to 9‰). Results from base model, adjusted for age, sex, and body mass index, showed that MN frequency would increase 1.38 (95%confidential interval: 1.34, 1.43) per 100 µg/L increment in BLLs. Using categorized exposure variable analyses, a BLLs dose-response increase in MN frequency was observed: 2.74 (2.13, 3.51), 3.43 (2.73, 4.32), 4.41 (3.89, 5.01) to 6.86 (6.02, 7.81). Mediation analysis indicated that Line-1 methylation significantly mediated 3.6% of the association of BLLs with MN frequency. Occupational Pb exposure induces MN frequency in a dose-response relationship. Part of this association was mediated by Line-1 promotor methylation.

Biomarkers for assessing chronic toxicity of carbamazepine, an anticonvulsants drug on Pangasianodon hypophthalmus (Sauvage, 1878).

In recent times, carbamazepine (CBZ) as an anticonvulsants drug has raised attention because of its safety concern in the aquatic environment. The present study aimed to evaluate the sub-lethal effects of CBZ (1%, 0.1 % and 0.01 % of 96 h LC50) on P. hypophthalmus for 60 days based on haematological, biochemical, and genotoxicity biomarkers. Chronic exposure of CBZ altered blood profiles (total erythrocyte count, packed cell volume, haemoglobin) and serum biomarkers such as alkaline phosphates, cholesterol, lactate dehydrogenase and transaminase enzymes. Oxidative stress biomarkers such as superoxide dismutase (SOD) and catalase (CAT) activity were also substantially affected in all treatments. Genotoxicity study revealed the formation of micronucleus in erythrocytes of exposed fish. Integrated Biomarker Response (IBR) study showed cholesterol, serum glutamic oxaloacetic transaminase (SGOT) in serum and SOD, CAT in liver tissue are the best organ-based enzyme biomarkers. The present report concludes that an environmentally realistic concentration of CBZ can pose a serious threat to aquatic organisms.

Genetic damage in coal and uranium miners.

Mining has a direct impact on the environment and on the health of miners and is considered one of the most hazardous occupations worldwide. Miners are exposed to several occupational health risks, including genotoxic substances, which may cause adverse health effects, such as cancer. This review summarizes the relation between DNA damage and mining activities, focusing on coal and uranium miners. The search was performed using electronic databases, including original surveys reporting genetic damage in miners. Additionally, a temporal bibliometric analysis was performed using an electronic database to create a map of cooccurrence terms. The majority of studies were performed with regard to occupational exposure to coal, whereas genetic damage was assessed mainly through chromosomal aberrations (CAs), micronuclei (MNs) and comet assays. The bibliometric analysis demonstrated associations of coal exposure with silicosis and pneumoconiosis, uranium miners with lung cancer and tumors and some associated factors, such as age, smoking, working time and exposure to radiation. Significantly higher DNA damage in miners compared to nonexposed groups was observed in most of the studies. The timeline reveals that classic biomarkers (comet assay, micronucleus test and chromosomal aberrations) are still important tools to assess genotoxic/mutagenic damage in occupationally exposed miners; however, newer studies concerning genetic polymorphisms and epigenetic changes in miners are being conducted. A major challenge is to investigate further associations between miners and DNA damage and to encourage further studies with miners of other types of ores.

Consumption pattern and genotoxic potential of various smokeless tobacco products in Assam, India: A public health concern.

Smokeless tobacco (SLT) consumption is presumed to be one of the major causes of high incidence of oral cancer in India. The present study aimed to document various types of SLT products consumed and their potential impact on the genome instability on the population from Assam state in Northeast India. A cross-sectional study (n = 5000) showed that 60.56 % of the study population consumed at least one of the three forms (sadagura, zarda and khaini) of SLT of which 52.0 % were only sadagura users. Genotoxicity assessment using buccal cytome assay in 240 age and sex matched volunteers revealed that except for zarda, other forms of SLT induced significantly higher incidence micronuclei in the buccal epithelial cells compared to the control individuals. Similar effects were also observed in other cytome parameters related to cell proliferation, cytokinesis defects and cell death. Significantly higher incidence of micronucleus was observed among sadagura and khaini users in lymphocyte cytokinesis-blocked micronucleus assay. The addition of lime in sadagura increased the pH and anion levels which possibly result in higher absorption and may lead to the development of cellular anomalies.

Nabumetone induced photogenotoxicity mechanism mediated by ROS generation under environmental UV radiation in human keratinocytes (HaCaT) cell line.

Nabumetone (NB) is a non-steroidal anti-inflammatory drug (NSAID), prescribed for managing pain associated with acute/chronic rheumatoid arthritis, osteoarthritis and other musculoskeletal disorders. Though some incidences of photosensitivity have been reported, there is limited information available on its phototoxicity potential. In this study, NB photodegraded in a time-dependant manner (0-4 h) under UVA (1.5 mW/cm2), UVB (0.6 mW/cm2) and natural sunlight as observed through UV-vis spectrophotometer and the results were further confirmed with Ultra High-Performance Liquid Chromatography (UHPLC). Photosensitized NB generated reactive oxygen species (ROS) as observed by lipid peroxidation, suggesting oxidative degradation of lipids in cell membrane, thereby resulting in cell damage. MTT and NRU (neutral red uptake) assays revealed that NB induced phototoxicity in concentration-dependent manner (0.5, 1, 5, 10 µg/ml) under UVA, UVB and sunlight exposure (30 min) in human keratinocytes cell line (HaCaT), with significant phototoxicity at the concentration of 5 µg/ml. Photosensitized NB generated intracellular ROS, disrupted mitochondrial and lysosomal membrane integrity, resulting in cell death. UV-induced genotoxicity by NB was confirmed through micronuclei generation, γ-H2AX induction and cyclobutane pyrimidine dimer formation. This is the first study which showed the phototoxicity and photogenotoxicity potential of NB in HaCaT cell line. We also observed that photosensitized NB upregulated inflammatory markers, such as COX-2 and TNFα. This study proposes that sunlight exposure should be avoided by patients using nabumetone and proper guidance should be provided by clinicians regarding photosensitivity of drugs for better safety and efficacy.

In vitro toxicological evaluation of a tobacco heating product THP COO and 3R4F research reference cigarette on human lung cancer cells.

Cigarette smoking increases health risks, such as respiratory diseases and heart diseases. Despite the decline in smoking rates in some countries, millions of adults still choose to smoke cigarettes. The use of next-generation nicotine delivery devices, such as tobacco heating products (THPs), may become a potentially safer alternative to smoking. Here, we report on the development of an electrically heated THP, coded as THP COO, with three different flavored tobacco sticks. The purpose of the study was to measure the levels of a list of harmful and potentially harmful constituents (HPHCs) in the total particulate matter (TPM) generated and to conduct a set of toxicological assessments of THP COO as compared with 3R4F reference cigarette. For all 55 HPHCs identified, the levels generated by the THP tobacco sticks were significantly lower in comparison to those in 3R4F TPM. The rate of reduction of HPHCs was between 68.6% and 99.9% under Health Canada Intense (HCI) smoking regimen. Human lung cancer cells (NCI-H292) exposed to 3R4F TPM showed dose-dependent responses for most of the 15 in vitro toxicity endpoints, whereas those exposed to comparable doses of THP COO TPMs did not. Therefore, exclusive use of the THP COO products may reduce the exposure of those tested HPHCs and thus potentially reduce health risk of smoking.

Micronucleus Formation in Primary Oropharyngeal Epithelial Cells Reveals Mutagenicity of Cement Dusts.

BACKGROUND/AIM: Epidemiological studies showed an increased risk of developing laryngeal head and neck squamous cell carcinoma (HNSCC) for employees working in the construction business. This suggested a causal link between exposure to cement particles and development of HNSCC but data were missing. MATERIALS AND METHODS: We established an Organisation for Economic Co-operation and Development (OECD) guideline 487-conform micronucleus assay (MNA) using oropharyngeal mucosa-derived primary epithelial cells (OPCs) ex vivo. OPCs from healthy mucosa of 52 donors were cultured in vitro and incubated with serial concentrations of two common cement particles. Mitomycin C was used as a soluble positive control, and TiO2 and DQ12 were used as negative and positive particle controls. Bi-nucleated cells were counted and the mitotic index (MI) was determined. Subsequently, micronuclei-containing bi-nucleated cells (MN+) were counted. RESULTS: Cement particles, in concentrations not significantly reducing ex vivo proliferation according to mitotic index, dose-dependently increased micronuclei formation. CONCLUSION: Through the establishment of an OECD guideline 487 conform MNA, we demonstrate the mutagenic effects of cement on human OPCs.

Morphological, behavioral and genotoxic effects of glyphosate and 2,4-D mixture in tadpoles of two native species of South American amphibians.

Pesticide contamination is an important factor in the global decline of amphibians. The herbicides glyphosate and 2,4-D are the most applied worldwide. These herbicides are often found in surface waters close to agricultural areas. This study aims at evaluating the chronic effects caused by glyphosate + 2,4-D mixture in Boana faber and Leptodactylus latrans tadpoles. The combined solution of the glyphosate and 2,4-D, in 5 different concentrations, was applied for 168 h. Herbicide mixtures did not affect the survival of the exposed tadpoles but growth and swimming activity were altered; besides causing several damages in the mouth and intestine. The erythrocytes showed micronuclei and other nuclear abnormalities. There is an ecological risk in the exposure of tadpoles of B. faber and L. latrans from the mixture of glyphosate + 2,4-D. Therefore, the approach used in this study provides important information on how commonly used pesticides can affect non-target organisms.

Biomonitoring of workers employed in a titanium dioxide production plant: Use of buccal micronucleus cytome assay as noninvasive biomarker to evaluate genotoxic and cytotoxic effects.

We aimed to evaluate whether TiO2 production process induces genotoxic and cytotoxic effects on the first target organ of inhalable particles by a sensitive and noninvasive biomarker of effect. Final aim was to find a useful and suitable tool to assess and manage the risk of TiO2 occupational exposure. We enrolled 40 workers employed in TiO2 production, 5 office workers, and 18 external controls. Buccal micronucleus cytome assay (BMCyt assay) was applied because it allows to evaluate micronucleus (MN), nuclear buds (NB), and broken eggs (BE) indicating the presence of chromosomal instability and gene amplification and binucleated cells (BIN), karyolytic cells (KL), and condensed chromatin (CC) indicating cytokinesis defect or arrest, cell death and apoptosis respectively. We characterized the exposure measuring inhalable and respirable particles by personal monitoring. BMCyt-assay showed in exposed workers compared with external controls a higher value of MN frequency (2.57 vs. 0.05‰, p < .001) and MN positivity, evaluated as percentage of subjects with MN frequency higher than a 1.5‰ cut-off value (52.5 vs. 0%). We also found in exposed workers higher frequency of BE + NB (2.41 vs. 0.22‰, p = .002), BIN (9.45 vs. 8.44‰, p = .047) and CC (1.80 vs. 0.21, p = .001) than in controls. Moreover, we found a relationship between personal monitoring results and presence of MN and other cellular anomalies. This study demonstrates induction of genotoxic and cytotoxic effects on buccal cells of workers involved in TiO2 production, suggesting the suitability of BMCyt assay as tool for risk assessment and management of TiO2 exposure.

Disruption of DNA polymerase ζ engages an innate immune response.

In mammalian cells, specialized DNA polymerase ζ (pol ζ) contributes to genomic stability during normal DNA replication. Disruption of the catalytic subunit Rev3l is toxic and results in constitutive chromosome damage, including micronuclei. As manifestations of this genomic stress are unknown, we examined the transcriptome of pol ζ-defective cells by RNA sequencing (RNA-seq). Expression of 1,117 transcripts is altered by ≥4-fold in Rev3l-disrupted cells, with a pattern consistent with an induction of an innate immune response. Increased expression of interferon-stimulated genes at the mRNA and protein levels in pol ζ-defective cells is driven by the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-signaling partner stimulator of interferon genes (STING) pathway. Expression of key interferon-stimulated chemokines is elevated in basal epithelial mouse skin cells with a disruption of Rev3l. These results indicate that the disruption of pol ζ may simultaneously increase sensitivity to genotoxins and potentially engage parts of the innate immune response, which could add an additional benefit to targeting pol ζ in cancer therapies.

Cytotoxic and Genotoxic Effects of Cyanobacterial and Algal Extracts-Microcystin and Retinoic Acid Content.

In the last decade, it has become evident that complex mixtures of cyanobacterial bioactive substances, simultaneously present in blooms, often exert adverse effects that are different from those of pure cyanotoxins, and awareness has been raised on the importance of studying complex mixtures and chemical interactions. We aimed to investigate cytotoxic and genotoxic effects of complex extracts from laboratory cultures of cyanobacterial species from different orders (Cylindrospermopsis raciborskii, Aphanizomenon gracile, Microcystis aeruginosa, M. viridis, M. ichtyoblabe, Planktothrix agardhii, Limnothrix redekei) and algae (Desmodesmus quadricauda), and examine possible relationships between the observed effects and toxin and retinoic acid (RA) content in the extracts. The cytotoxic and genotoxic effects of the extracts were studied in the human hepatocellular carcinoma HepG2 cell line, using the MTT assay, and the comet and cytokinesis-block micronucleus (cytome) assays, respectively. Liquid chromatography electrospray ionization mass spectrometry (LC/ESI-MS) was used to detect toxins (microcystins (MC-LR, MC-RR, MC-YR) and cylindrospermopsin) and RAs (ATRA and 9cis-RA) in the extracts. Six out of eight extracts were cytotoxic (0.04-2 mgDM/mL), and five induced DNA strand breaks at non-cytotoxic concentrations (0.2-2 mgDM/mL). The extracts with genotoxic activity also had the highest content of RAs and there was a linear association between RA content and genotoxicity, indicating their possible involvement; however further research is needed to identify and confirm the compounds involved and to elucidate possible genotoxic effects of RAs.

Manool, a diterpene from Salvia officinalis, exerts preventive effects on chromosomal damage and preneoplastic lesions.

The present study aimed to evaluate the effect of the manool diterpene on genomic integrity. For this purpose, we evaluated the influence of manool on genotoxicity induced by mutagens with different mechanisms of action, as well as on colon carcinogenesis. The results showed that manool (0.5 and 1.0 µg/ml) significantly reduced the frequency of micronuclei induced by doxorubicin (DXR) and hydrogen peroxide in V79 cells but did not influence genotoxicity induced by etoposide. Mice receiving manool (1.25 mg/kg) exhibited a significant reduction (79.5%) in DXR-induced chromosomal damage. The higher doses of manool (5.0 and 20 mg/kg) did not influence the genotoxicity induced by DXR. The anticarcinogenic effect of manool (0.3125, 1.25 and 5.0 mg/kg) was also observed against preneoplastic lesions chemically induced in rat colon. A gradual increase in manool doses did not cause a proportional reduction of preneoplastic lesions, thus demonstrating the absence of a dose-response relationship. The analysis of serum biochemical indicators revealed the absence of hepatotoxicity and nephrotoxicity of treatments. To explore the chemopreventive mechanisms of manool via anti-inflammatory pathways, we evaluated its effect on nitric oxide (NO) production and on the expression of the NF-kB gene. At the highest concentration tested (4 µg/ml), manool significantly increased NO production when compared to the negative control. On the other hand, in the prophylactic treatment model, manool (0.5 and 1.0 µg/ml) was able to significantly reduce NO levels produced by macrophages stimulated with lipopolysaccharide. Analysis of NF-kB in hepatic and renal tissues of mice treated with manool and DXR revealed that the mutagen was unable to stimulate expression of the gene. In conclusion, manool possesses antigenotoxic and anticarcinogenic effects and its anti-inflammatory potential might be related, at least in part, to its chemopreventive activity.

Assesment of hematotoxic, oxidative and genotoxic damage potentials of fipronil in rainbow trout Oncorhynchus mykiss, Walbaum.

In this study, changes in the blood tissue of rainbow trout (Oncorhynchus mykiss, Walbaum, 1792) caused by Fipronil (FP) insecticide were investigated using different biomarkers (Hematology parameters, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), malondialdehyde (MDA), paraoxonase (PON), arylesterase (ARE), myeleperoxidase (MPO), micronucleus (MN), 8-hydroxy-2-deoxyguanosine (8-OHdG)) level and caspase-3 activity. Statistically significant alterations in hematology parameters occurred with FP effect. In blood tissue, dose-dependent inhibition was determined in SOD-CAT-GPX-PON and ARE enzyme activities, but MDA and MPO were induced statistically significant. The results of MN assay were compared with the control group and it was obtained that genotoxicity of different dose groups was similar. The level of 8-OHdG and the activity and caspase-3 examined in blood tissue was increased depending on the dose. It was determined with different biomarkers that this insecticide caused physiological stress changes in the tissues examined.