Genotoxic and antiproliferative properties of Endopleura uchi bark aqueous extract

The bark extract from Endopleura uchi has been widely used in traditional medicine to treat gynecological-related disorders, diabetes, and dyslipidemias albeit without scientific proof. In addition, E. uchi bark extract safety, especially regarding mutagenic activities, is not known. The aim of this study was to determine the chemical composition, antitumor, and toxicological parameters attributed to an E. uchi bark aqueous extract. The phytochemical constitution was assessed by colorimetric and chromatographic analyzes. The antiproliferative effect was determined using sulforhodamine B (SRB) assay using 4 cancer cell lines. Cytotoxic and genotoxic activities were assessed utilizing MTT and comet assays, respectively, while mutagenicity was determined through micronucleus and Salmonella/microsome assays. The chromatographic analysis detected predominantly the presence of gallic acid and isoquercitrin. The antiproliferative effect was more pronounced in human colon adenocarcinoma (HT-29) and human breast cancer (MCF-7) cell lines. In the MTT assay, the extract presented an IC50 = 39.1 µg/ml and exhibited genotoxic (comet assay) and mutagenic (micronucleus test) activities at 20 and 40 µg/ml in mouse fibroblast cell line (L929) and mutagenicity in the TA102 and TA97a strains in the absence of S9 mix. Data demonstrated that E. uchi bark possesses bioactive compounds which exert cytotoxic and genotoxic effects that might be associated with its antitumor potential. Therefore, E. uchi bark aqueous extract consumption needs to be approached with caution in therapeutic applications.

Caenorhabditis elegans as a suitable model to evaluate the toxicity of water from Rolante River, southern Brazil

Urbanization and agricultural activities increased environmental contaminants. Integrated analysis of water parameters and bioassays represents an essential approach to evaluating aquatic resource quality. This study aimed to assess water quality by microbiological and physicochemical parameters as well as the toxicological effects of water samples on the Ames test and Caenorhabditis elegans model. Samples were collected during (collection 1) and after (collection 2) pesticide application in the upper (S1), middle (S2), and lower (S3) sections of the Rolante River, southern Brazil. Metals were determined by GFAAS and pesticides by UPLC-MS/MS. Bioassays using the Ames test and the nematode C. elegans were performed. Levels of microbiological parameters, as well as Mn and Cu were higher than the maximum allowed limits established by legislation in collection 2 compared to collection 1. The presence of pesticide was observed in both collections; higher levels were found in collection 1. No mutagenic effect was detected. Significant inhibition of body length of C. elegans was found in collection 1 at S2 (P < 0.001) and S3 (P < 0.001) and in collection 2 at S2 (P = 0.004). Comparing the same sampling site between collections, a significant difference was found between the site of collection (F(3,6)=8.75, P = 0.01) and the time of collection (F(1,2)=28.61, P = 0.03), for the S2 and S3 samples. C. elegans model was useful for assessing surface water quality/toxicity. Results suggest that an integrated analysis for the surface water status could be beneficial for future approaches.

Toxicological assessment of minoxidil: A drug with therapeutic potential besides alopecia

Minoxidil is regularly prescribed for alopecia, and its therapeutic potential has expanded in recent times. However, few studies have been conducted to evaluate its toxicity, and controversial findings regarding its mutagenic activities remain unsolved. This study aimed to access cytotoxic, genotoxic, and mutagenic properties of minoxidil using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay, comet assay, and micronucleus test in mouse fibroblast (L929) cells and its point mutation induction potential in the Salmonella/microsome assay. Furthermore, an in vivo toxicity assessment was conducted in Caenorhabditis elegans. Minoxidil showed cytotoxicity at 2.0 mg/mL in MTT assay. Genotoxicity was observed after 3 h treatment in L929 cells using comet assay. No mutagenic effect was observed in both the micronucleus test and the Salmonella/microsome assay. The lethal dose 50 in C. elegans was determined to be 1.75 mg/mL, and a delay in body development was detected at all concentrations. In conclusion, minoxidil induces DNA damage only in early treatment, implying that this DNA damage may be repairable. This observation corroborates the absence of mutagenic activities observed in L929 cells and Salmonella typhimurium strains. However, the toxicity of minoxidil was evident in both C. elegans and L929 cells, underscoring the need for caution in its use.

Toxicological profile of the Hymenaea courbaril stem bark hydroalcoholic extract using in vitro bioassays and an alternative in vivo Caenorhabditis elegans model

Hymenaea genus has been used in folk medicine in Brazil, but few studies investigated its toxicity profile. Thus, the aim of this study was to determine toxicological parameters of Hymenaea courbaril stem bark hydroalcoholic extract by utilizing three cell lines including murine macrophages (RAW 264.7), mouse fibroblast cells (L929) and human lung fibroblast (MRC-5), as well as Salmonella/microsome assay, and in vivo Caenorhabditis elegans model. The predominant detected phytoconstituents in the extract were coumarins, flavonoids, phenolics, tannins and saponins and by HPLC analysis, astilbin (AST) was found to be the main component. The DPPH assay demonstrated that H. courbaril hydroalcoholic extract exhibited potent antioxidant activity, with an IC50 of 3.12 μg/ml. The extract at concentrations of 400 and 800 μg/ml decreased cell viability 48 hr after treatment in L929 and MRC-5 cell lines. In the Raw 264.7 strain, just the highest concentration (800 μg/ml) lowered cell viability within 48 hr following exposure. The concentration of 100 μg/ml did not markedly affect cell viability in the trypan blue assay. In the alkaline comet assay the extract was found to be non-genotoxic. In the Ames test, the extract exhibited low mutagenic potential without metabolic activation, since only the highest concentrations produced an effect. H. courbaril extract only affected the survival of C. elegans at concentrations of 800 and 1600 μl/ml. These findings demonstrate that H. courbaril extract appears to exert low toxicity as evidenced in vitro and mutagenicity assays; however, the biological relevance of the response of C. elegans survival to safety assessments needs further studies.

Morphine decreases cytotoxicity and mutagenicity of doxorubicin in vitro: Implications for cancer chemotherapy

Morphine is the most common opioid analgesic administered to treat pain in patients undergoing cancer chemotherapy. This study aimed to evaluate the cytotoxic and mutagenic effects of morphine alone and in combination with doxorubicin (Dox), an antineoplastic agent largely used in patients with solid cancers. Cytotoxicity was evaluated in neuroblastoma (SH-SY5Y) and fibroblast (V79) cells using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay while mutagenicity was assessed using the Salmonella/microsome assay in the absence and in the presence of S9 mix. Morphine showed a cytotoxic effect mainly on SH-SY5Y cells and reduced the cytotoxic effects of Dox when evaluated in a co-treatment procedure. In the Salmonella/microsome assay, it was observed that morphine did not induce mutations and, in fact, decreased the mutagenic effects induced by Dox in TA98 and TA102 strains in the absence of metabolic activation. Furthermore, in the presence of metabolic activation, no induction of mutations was observed with morphine. In conclusion, morphine decreased Dox cytotoxicity in both neuronal and non-neuronal cells and showed antimutagenic effects in the TA102 strain which detects mutagens inducing DNA oxidative damages. However, morphine decreased frameshift mutations induced by Dox in non-cytotoxic concentrations, an effect suggesting interference of Dox intercalation activity that could decrease its chemotherapeutic efficacy. These compelling findings highlight the importance of conducting further studies to explore the potential implications of co-administering morphine and Dox during cancer chemotherapy.

Toxicological potential of Aloysia gratissima: Insights from chemical analysis and in vitro studies

ETHNOPHARMACOLOGICAL RELEVANCE

Aloysia gratissima leaves are popularly used to treat respiratory, digestive, and nervous system disorders. Several studies have been carried out to determine the biological activity of A. gratissima, such as its antibacterial and anti-edematogenic activities, but despite the beneficial uses of A. gratissima, few studies have examined the toxicological profile of this plant.

AIM OF THE STUDY

This study aimed to determine the chemical composition, cytotoxic, genotoxic, mutagenic potential, and antioxidant activity of an aqueous extract of A. gratissima leaves (AG-AEL).

MATERIAL AND METHODS

The phytochemical constitution of AG-AEL was assessed by colorimetric analyses and High-performance liquid chromatography (HPLC). The inorganic elements were detected by Particle-Induced X-ray Emission (PIXE). The antioxidant, cytotoxicity, genotoxic, and mutagenic activities were evaluated in vitro by Di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH), Sulforhodamine B (SRB) assay, comet assay, and Salmonella/microsome assays.

RESULTS

AG-AEL indicated the presence of terpenoids, flavonoids, and phenolic acids. HPLC detected rutin at 2.41 ± 0.33 mg/100 mg. PIXE analysis indicated the presence of Mg, Si, P, S, K, Ca, Mn, and Zn. The 50% inhibitory concentration was 84.17 ± 3.17 μg/mL in the DPPH assay. Genotoxic effects were observed using the Comet assay in neuroblastoma (SH-SY5Y) cells and mutations were observed in TA102 and TA97a strains. The extract showed cytotoxic activities against ovarian (OVCAR-3), glioblastoma (U87MG), and colon (HT-29) cancer cell lines.

CONCLUSIONS

In conclusion, AG-AEL increased DNA damage, induced frameshift, and oxidative mutations, and showed cytotoxic activities against different cancer cells. The in vitro toxicological effects observed suggest that this plant preparation should be used with caution, despite its pharmacological potential.

Geniposide and asperuloside alter the COX-2 and GluN2B receptor expression after pilocarpine-induced seizures in mice

Asperuloside (ASP) and geniposide (GP) are iridoids that have shown various biological properties, such as reduction of inflammation, oxidative stress, and neuroprotection. The aim of this study was to investigate the mechanism of action of ASP and GP through the experimental model of pilocarpine-induced seizures. Mice were treated daily with saline, valproic acid (VPA), GP (5, 25, or 50 mg/kg), or ASP (20 or 40 mg/kg) for 8 days. Pilocarpine (PILO) treatment was administered after the last day of treatment, and the epileptic behavior was recorded for 1 h and analyzed by an adapted scale. Afterward, the hippocampus and blood samples were collected for western blot analyses, ELISA and comet assay, and bone marrow to the micronucleus test. We evaluated the expression of the inflammatory marker cyclooxygenase-2 (COX-2), GluN2B, a subunit of the NMDA receptor, pGluR1, an AMPA receptor, and the enzyme GAD-1 by western blot and the cytokine TNF-α by ELISA. The treatments with GP and ASP were capable to decrease the latency to the first seizure, although they did not change the latency to status epilepticus (SE). ASP demonstrated a genotoxic potential analyzed by comet assay; however, the micronuclei frequency was not increased in the bone marrow. The GP and ASP treatments were capable to reduce COX-2 and GluN2B receptor expression after PILO exposure. This study suggests that GP and ASP have a protective effect on PILO-induced seizures, decreasing GluN2B receptor and COX-2 expression.

Evaluation of the efficacy and toxicity of oral and topical pumpkin oil on the hair growth of mice

This study aimed to evaluate the efficacy and safety of a topical and oral administration of pumpkin seed oil (PSO) on the hair growth of BALB/c male mice. The animals had their dorsal area shaved (2 ×2 cm) and they were divided into 6 experimental groups. They received orally saline (OS), finasteride (F), or PSO (OP) for 14 days; or topically saline (TS), minoxidil (M), or PSO (TP) for 7 days. The euthanasia of all of the mice occurred on the 22nd day, and the histological slides from the skin area were analyzed. Lipoperoxidation in the liver was assessed through the TBARS method and was also evaluated by the antioxidant enzymes (SOD and CAT). The comet assay and the micronucleus tests were performed for genotoxic/mutagenic safety analyses. A significant increase in the number of hair follicles in the TP group was seen (8.8 ± 0.8) but it was disorganized, with loose dermal collagen. Finasteride presented a significant increase in the levels of the TBARS, SOD, and CAT in the liver, and M increased the DNA damage in the blood and the liver tissues. PSO did not induce any significant changes. In addition, PSO did not induce genotoxic or mutagenic effects. In conclusion, the oral PSO for 14 days acted in the proliferation of the hair follicles, without toxicity signals in the liver. DATA AVAILABILITY: The authors confirm that all of the relevant data is included in the article and/or in the supplementary information file.

Melatonin Attenuates Inflammation, Oxidative Stress, and DNA Damage in Mice with Nonalcoholic Steatohepatitis Induced by a Methionine- and Choline-Deficient Diet

Nonalcoholic steatohepatitis (NASH) is a disease with a high incidence worldwide, but its diagnosis and treatment are poorly managed. In this study, NASH pathophysiology and DNA damage biomarkers were investigated in mice with NASH treated and untreated with melatonin (MLT). C57BL/6 mice were fed a methionine- and choline-deficient (MCD) diet for 4 weeks to develop NASH. Melatonin was administered at 20 mg/kg during the last 2 weeks. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured, and hepatic tissue was dissected for histological analysis, evaluation of lipoperoxidation, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as nuclear factor-erythroid 2 (Nrf2), tumor necrosis factor alpha (TNF-α), inducible nitric oxide synthase (iNOS), and transforming growth factor beta (TGF-β) expression by immunohistochemistry. DNA damage was evaluated using Comet assay, while a micronucleus test in bone marrow was performed to assess the genomic instability associated with the disease. Melatonin decreased AST and ALT, liver inflammatory processes, balloonization, and fibrosis in mice with NASH, decreasing TNF-α, iNOS, and TGF-β, as well as oxidative stress, shown by reducing lipoperoxidation and intensifying Nrf2 expression. The SOD and GPx activities were increased, while CAT was decreased by treatment with MLT. Although the micronucleus frequency was not increased in mice with NASH, a protective effect on DNA was observed with MLT treatment in blood and liver tissues using Comet assay. As conclusions, MLT slows down the progression of NASH, reducing hepatic oxidative stress and inflammatory processes, inhibiting DNA damage via anti-inflammatory and antioxidant actions.

Photobiomodulation intervention improves oxidative, inflammatory, and morphological parameters of skeletal muscle in cirrhotic Wistar rats

Photobiomodulation (PBM) might be an intervention method to mitigate sarcopenia in cirrhotic patients. Given the lack of research on this issue, the goal of this study was to evaluate possible beneficial effects of PBM on the structural and functional properties of skeletal muscle from cirrhotic rats. Cirrhosis was induced by secondary bile duct ligation (BDL). Wistar rats were randomized into four groups: sham-operated control (Sham), Sham + PBM, BDL, and BDL + PBM. After cirrhosis induction, a dose of PBM (1 J; 100mW; 10 s; 880 nm; 6 × per week) was applied to each quadriceps, from the 15th to the 45th day after surgery. The locomotor ability was performed using an open-field task. The muscle structure was analyzed using histological methods. Cell damage was also evaluated assessing oxidative stress and DNA damage markers, and IL-1β pro-inflammatory interleukin by immunohistochemical analysis. An increase in the number of crossings was observed in the BDL + PBM group in relation to BDL. The BDL group showed muscle atrophy and increased IL-1β in relation to Sham, while in the BDL + PBM group, the fiber muscle was restructured and there was a decrease of IL-1 β. TBARS increased in the liver and muscle tissues in the BDL group and decreased it in the BDL + PBM group. SOD increased while CAT decreased in the BDL + PBM group in relation to the BDL group. No genotoxic or mutagenic effect was observed for PBM treatment. PBM improved the locomotion and the morphology of the muscle fibers, decreasing oxidative stress and inflammation, without causing DNA damage in cirrhotic rats.

Evaluation of toxicological aspects of three new benzoxazole compounds with sunscreen photophysical properties using in silico and in vitro methods

Sunscreening chemicals protect against damage caused by sunlight most absorbing UVA or UVB radiations. In this sense, 2-(2'-hydroxyphenyl)benzoxazole derivatives with amino substituents in the 4' and 5' positions have an outstandingly high Sun Protection Factor and adequate photostability, but their toxicity is not yet known. This study aimed to evaluate the toxicity of three synthetic 2-(2'-hydroxyphenyl)benzoxazole derivatives for their possible application as sunscreens. In silico tools were used in order to assess potential risks regarding mutagenic, carcinogenic, and skin sensitizing potential. Bioassays were performed in L929 cells to assess cytotoxicity in MTT assay and genotoxic activities in the Comet assay and micronucleus test. Also, the Salmonella/microsome assay was performed to evaluate gene mutations. The in silico predictions indicate a low risk of mutagenicity and carcinogenicity of the compounds while the skin sensitizing potential was low or inconclusive. The 2-(4'-amino-2'-hydroxyphenyl)benzoxazol compound was the most cytotoxic and genotoxic among the compounds evaluated in L929 cells, but none induced mutations in the Salmonella/microsome assay. The amino substituted at the 4' position of the phenyl ring appears to have greater toxicological risks than substituents at the 5' position of 2-(phenyl)benzoxazole. The findings warrant further studies of these compounds in cosmetic formulations.

Genotoxic effect induced by dried nicotiana tabacum leaves from tobacco barns (kiln-houses) in chinese hamster lung fibroblast cells (V79)

Nicotiana tabacum is the most cultivated tobacco species in the state of Rio Grande do Sul, Brazil. Workers who handle the plant are exposed to the leaf components during the harvesting process and when separating and classifying the dried leaves. In addition to nicotine, after the drying process, other components may be found including tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, as well as pesticides residues. The objective of this study was to examine the genotoxicity attributed to the aqueous extract of dried tobacco leaves obtained from tobacco barns using Chinese hamster lung fibroblast cells (V79) as a model system by employing alkaline comet assay, micronucleus (MN) and Ames test. MTT assay was used to assess cytotoxicity and establish concentrations for this study. Data demonstrated cell viability > 85% for concentrations of 0.625-5 mg/ml while the comet assay indicated a significant increase in DNA damage at all concentrations tested. A significant elevation of MN and nuclear buds (NBUD) was found for 5 mg/ml compared to control and other dry tobacco leaves concentrations (0.625-2.5 mg/ml). Mutagenicity was not found using the Salmonella/Microsome test (TA98, TA100, and TA102 strains) with and without metabolic activation. The concentration of inorganic elements was determined employing the PIXE technique, and 13 inorganic elements were detected. Using CG/MS nicotine amounts present were 1.56 mg/g dry tobacco leaf powder. Due to the observed genotoxicity in V79 cells, more investigations are needed to protect the health of tobacco workers exposed daily to this complex mixture of toxic substances present in dry tobacco leaves.

Evaluation of lipolysis and toxicological parameters of low-level laser therapy at different wavelengths and doses in the abdominal subcutaneous tissue

Investigate the effects of low-level lasers therapy (LLLT) aiming abdominal lipolysis. Female Wistar rats received applications of LLLT directly in the abdominal skin twice a week (5 weeks). Except the control group (n = 5), animals received treatments with red wavelength 660 nm being (I) R3.3 group (n = 5): 3.3 J/cm², and (II) R5 group (n = 5): 5 J/cm², or infrared wavelength 808 nm being (III) IR3.3 group (n = 5): 3.3 J/cm², and (IV) IR5 group (n = 5): 5 J/cm². Abdominal subcutaneous and liver tissues were evaluated histologically. Levels of thiobarbituric acid reactive substances (TBARS) and catalase (CAT) activity were analyzed in liver tissue. In the peripheral blood aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides, and total cholesterol were investigated. Micronucleus assay was performed in the bone marrow. Except for the IR3.3 group, all treated groups reduced the body weight (p < 0.001). The R5 group reduced the abdominal subcutaneous tissue weight and thickness (p < 0.05), even though all treated groups reduced the number of adipocytes and its size (p < 0.001). No histological changes in the liver. There were no alterations in the triglycerides and LDL levels. The IR5 group increased the total cholesterol levels and decreased the HDL, ALT (both p < 0.05), and AST levels (p < 0.001). The group IR3.3 showed higher levels of ALP (p < 0.01). The R3.3 group increased the TBARS and CAT activity (p < 0.05). No mutagenic effects were found. The red laser treatment at 5 J/cm² led to lipolysis and did not alter the liver's parameters.

Sarcopenia, oxidative stress and inflammatory process in muscle of cirrhotic rats - Action of melatonin and physical exercise

Sarcopenia is one of the most common features of cirrhosis, contributing to morbidity and mortality in this population. We aimed to evaluate the effect of melatonin (MLT) and exercise (EX) on the quadriceps muscle in rats with biliary cirrhosis induced by bile duct ligation (BDL). We used 48 males (mean weight = 300 g), divided into eight groups. A 20 mg/Kg MLT dose was administered via i.p. (1 x daily), and the EX, the animals were set to swim in couples for 10 min each day. Upon completion, blood, liver, and quadriceps samples were taken for analysis. In the liver enzymes analysis and comet assay results, a reduction was observed in the groups treated with MLT with/or EX comparing to the BDL group. In the evaluation of substances that react to thiobarbituric acid (TBARS), nitric oxide levels (NO), and tumor necrosis factor-alpha levels (TNF-α), there was a significant increase in the BDL group and a reduction in the treated groups. In the activity of the superoxide dismutase enzyme (SOD) and interleukin-10 levels (IL-10) concentrations, there was a significant increase in the treated groups of the BDL group. Histological analysis revealed muscle hypotrophy in the BDL group in comparison with the control group (CO) and increased muscle mass in the treated groups. There was an increase in weight gain and phase angle in the groups treated with MLT with/or EX comparing to the BDL group. We suggest that treatments may contribute to the reduction of muscle changes in cirrhotic patients.

Gamma-Decanolactone Alters the Expression of GluN2B, A1 Receptors, and COX-2 and Reduces DNA Damage in the PTZ-Induced Seizure Model After Subchronic Treatment in Mice

Gamma-decanolactone (GD) has been shown to reduce epileptic behavior in different models, inflammatory decreasing, oxidative stress, and genotoxic parameters. This study assessed the GD effect on the pentylenetetrazole (PTZ) model after acute and subchronic treatment. We evaluated the expression of the inflammatory marker cyclooxygenase-2 (COX-2), GluN2B, a subunit of the NMDA glutamate receptor, adenosine A1 receptor, and GD genotoxicity and mutagenicity. Male and female mice were treated with GD (300 mg/kg) for 12 days. On the tenth day, they were tested in the Hot Plate test. On the thirteenth day, all animals received PTZ (90 mg/kg), and epileptic behavior PTZ-induced was observed for 30 min. Pregabalin (PGB) (30 mg/kg) was used as a positive control. Samples of the hippocampus and blood were collected for Western Blotting analyses and Comet Assay and bone marrow to the Micronucleus test. Only the acute treatment of GD reduced the seizure occurrence and increased the latency to the first stage 3 seizures. Males treated with GD for 12 days demonstrated a significant increase in the expression of the GluN2B receptor and a decrease in the COX-2 expression. Acute and subchronic treatment with GD and PGB reduced the DNA damage produced by PTZ in males and females. There is no increase in the micronucleus frequency in bone marrow after subchronic treatment. This study suggests that GD, after 12 days, could not reduce PTZ-induced seizures, but it has been shown to protect against DNA damage, reduce COX-2 and increase GluN2B expression.

Evaluation of soils under the influence of coal mining and a thermoelectric plant in the city of Candiota and vicinity, Brazil

Coal burning generates gases, particles, and condensation by-products that are harmful to soil, water, and to the atmosphere. The aim of this study was to characterize and identify the cytotoxic and mutagenic potential of soil samples from the cities of Aceguá, Bagé, Candiota and Pinheiro Machado, near a large coal-fired power plant. Our study describes soil characteristics and contributes to the evaluation of the genotoxic activity of coal mining and burning, using the Comet Assay and Micronucleus test in V79 cells, as well as mutagenicity assays with Salmonella typhimurium strains. Comet Assay results show that the winter soil samples of Candiota and Pinheiro Machado induced a significant increase of the Damage Index for cells, as well as for the Aceguá summer sample. The micronucleus test did not detect differences between cities and seasons. A component analysis indicates associations between results obtained in Comet Assay and Ti and phenanthene concentrations for Pinheiro Machado during the winter, and Al for Aceguá during the summer and Zn during the winter. Results of Salmonella/microsome assays were negative, only Candiota and Pinheiro Machado samples showed a statistical increase of his + colonies in TA102. Our work describes biological data on these cells exposed to coal-contaminated soil, confirming the sensitivity of the Comet Assay in V79 cells and Salmonella/microsome assay for the evaluation of the effects of complex mixtures. These findings help to understand the spatial distribution of contaminants in the local soil related to a power plant, which is important for planning public safety actions.

In vivo treatment with a subacute low dose of 3-nitropropionic acid does not induce genotoxicity or mutagenicity in rats

3-nitropropionic acid (3-NP) is a toxin that causes neural damage in the striatum and can lead to the development of Huntington's disease manifestations in animal models. Several studies have shown genotoxicity related to the 3-NP treatment. This study investigated potential genotoxicity and mutagenicity that was induced by a low dose (6.25 mg/kg i. p.) 3-NP subacute treatment (daily, over 6 days) in a rat model. The arterial blood and the frontal cortex were analyzed by the comet assay and the bone marrow by micronucleus. Surprisingly, the 3-NP subacute treatment with the low dose did not show genotoxic or mutagenic effects.

Evaluation of toxicity and mutagenicity of a synthetic effluent containing azo dye after Advanced Oxidation Process treatment

Approximately 20% industrial water pollution comes from textile dyeing process, with Azo dyes being a major problem in this scenario and requiring new forms of efficient treatment. Effluent treatments using the Advanced Oxidation Processes (AOP) are justified by the potential of application in the dyed effluent treatments once they can change the Azo dye chemical structure. Thus, this study aimed to evaluate the toxicity and mutagenic capacity of a synthetic effluent containing Amido Black 10B (AB10B) azo dye before treatment with AOP, named Gross Synthetic Effluent (GSE), and after the AOP, named Treated Synthetic Effluent (TSE). Daphnia magna and Allium cepa tests were used to evaluate acute toxicity effects and chromosomal mutagenesis, respectively. The Salmonella/microsome assay was performed to evaluate gene mutations. In silico assays were also performed aiming to identify the mutagenic and carcinogenic potential of the degradation byproducts of AB10B. There was 100% immobility to D. magna after 24 h and 48 h of treatments with TSE, showing EC₅₀ values around 5%, whereas GSE did not show acute toxicity. However, GSE induced chromosomal mutations in A. cepa test. Both GSE and TSE were not able to induce gene mutations in S. typhimurium strains. These effects can be associated with two byproducts generated with the cleavage of the azo bonds of AB10B, 4-nitroaniline and -2-7-triamino-8-hydroxy-3-6-naphthalinedisulfate (TAHNDS). In conclusion, AOP is an efficient method to reduce the mutagenicity of synthetic effluent containing AB10B and additional methods should be applied aiming to reduce the toxicity.

Myrciaria dubia Juice (camu-camu) Exhibits Analgesic and Antiedematogenic Activities in Mice

The Myrciaria dubia (Myrtaceae) fruit is traditionally used to treat malnutrition due to its high levels of vitamin C and phenolic compounds. Because of its composition, this plant is very promising in the research of novel natural treatment for pain disorders. This study analyzed the phytochemical profile of M. dubia juice and assessed its antinociceptive and antiedematogenic potential. The phytochemical profile was determined through high-performance liquid chromatography (HPLC), the oral antinociceptive effect of M. dubia 50% juice (Md50) was evaluated by formalin, hot plate and Complete Freund's Adjuvant tests and the antiedematogenic activity by paw edema. HPLC revealed the presence of ascorbic acid, rutin, and ellagic acid as major compounds. Md50 showed an antinociceptive effect in the acute and chronic phases of the formalin test. In the hot plate test, Md50 also induced an antinociceptive effect of 0.5 up to 6 h, showing antinociceptive and antiedematogenic potential without changing the spontaneous locomotion of animals. All protocols were submitted and approved by the Ethics Committee for use of Animals of the Lutheran University of Brazil (protocol No. 2013-30P).

In vivo and in vitro toxicological evaluations of aqueous extract from Cecropia pachystachya leaves

leaves are popularly used to treat asthma and diabetes. Despite the widespread consumption of this plant, there are few scientific studies regarding its toxicological potential. In order to conduct a thorough study concerning the potential adverse effects, the aim of this study was to assess acute and subacute toxicity tests of crude aqueous extract from C. pachystachya leaves (CAE-Cp) using in vivomodel, as well as in vitro cytotoxicity, genotoxicity and antioxidant activity. In addition, genotoxicity, and cytotoxicity of chlorogenic acid (CGA) and cytotoxicity of isoorientin (ISOO) were also evaluated. The antioxidant activity was verified by DPPH, cytotoxicity using sulforhodamine B (SRB) assay and genotoxicity by comet assay on V79 cells. The phytochemical analysis of CAE-Cp detected flavonoids and tannins, CGA and ISOO as the major compounds utilizing HPLC. The total flavonoid content (6.52 mg/g EQ) and antioxidant activity (EC₅₀ = 62.15 µg/ml) of CAE-Cp were determined. In vitro evaluations with CAE-Cp showed genotoxic effects at 0.31 to 2.5 mg/ml and an expressive cytotoxicity on HT-29 (IC₅₀ = 4.43 µg/ml) cells. CGA was genotoxic against V79 cells at 0.07 mg/ml and cytotoxic against to HT-29 (IC₅₀ = 71.70 µg/ml), OVCAR-3 (IC₅₀ = 80.07 µg/ml), MCF-7 (IC₅₀ = 45.58 µg/ml) and, NCI-H460 (IC₅₀ = 71.89 µg/ml) cancer cell lines. Wistar rats treated with a single dose (2,000 mg/kg) CAE-Cp decreased hemoglobin levels after 14 days, although no significant toxicity was observed in animals after 28 days. In view of the in vitro cytotoxicity and genotoxicity detected, further studies are necessary to establish the safe use of CAE-Cp.

Lacosamide improves biochemical, genotoxic, and mitochondrial parameters after PTZ-kindling model in mice

This study evaluated the effect of lacosamide (LCM) on biochemical and mitochondrial parameters after PTZ kindling in mice. Male mice were treated on alternative days for a period of 11 days with LCM (20, 30, or 40 mg/kg), saline, or diazepam (2 mg/kg), before PTZ administration (50 mg/kg). The hippocampi were collected to evaluate free radicals, the activities of superoxide dismutase (SOD), catalase (CAT), and the mitochondrial complexes I-III, II, and II-III, as well as Bcl-2 and cyclo-oxygenase-2 (COX-2) expressions. Hippocampi, blood, and bone marrow were collected for genotoxic and mutagenic evaluations. LCM 40 mg/kg increased latency and decreased percentage of seizures, only on the 3rd day of observation. The dose of 30 mg/kg only showed positive effects on the percentage of seizures on the 2nd day of observation. LCM decreased free radicals and SOD activity and the dose of 40 mg/kg were able to increase CAT activity. LCM 30 and 40 mg/kg improved the enzymatic mitochondrial activity of the complex I-III and LCM 30 mg/kg improved the activity of the complex II. In the comet assay, the damage induced by PTZ administration was reduced by LCM 20 and 30 mg/kg. The dose of 20 mg/kg increased COX-2 expression while the highest dose used, 40 mg/kg, was able to reduce this expression when compared to the group treated with LCM 20 mg/kg. Although LCM did not produce the antiepileptogenic effect in vivo, it showed the neuroprotective effect against oxidative stress, bioenergetic dysfunction, and DNA damage induced by the repeated PTZ administration.

Antinociceptive and genotoxic assessments of the antagonist TRPV1 receptor SB-366791 on morphine-induced tolerance in mice

Chronic pain is mainly treated with opioid analgesics such as morphine. However, the use of these substances can cause adverse effects, including dependence and tolerance, necessitating the discovery of a new approach to analgesic therapies. The transient receptor potential vanilloid 1 (TRPV1) is linked to thermal sensibility and has been considered as a new therapeutic option for pain treatment. This study aims to investigate the antinociceptive effect and toxicity of SB-366791, a TRPV1 antagonist. Morphine-tolerant and morphine non-tolerant Swiss mice were submitted to the hot plate and thermal tail flick tests. Toxicological evaluations of the genotoxic and mutagenic activities of SB-366791 were assessed using a comet assay and micronucleus test, and the Salmonella/microsome mutagenicity assay. In the hot plate test, intrathecal injection of SB-366791 or morphine resulted in significantly increased antinociception in non-tolerant mice. SB-366791 also led to an analgesic effect in the tail flick test. Tolerant mice that received SB-366791 demonstrated a central antinociceptive effect in both thermal tests. No genotoxic effects were observed in the comet assay and no mutagenic effects were detected in the micronucleus test or in the Salmonella/microsome assay. Behavioral results of the thermal nociception tests show that SB-366791 has antinociceptive potential in both morphine-tolerant and non-tolerant mice and does not cause genotoxic or mutagenic effects. Nevertheless, new studies should be performed to clarify the activity and participation of vanilloid channels in the antinociception of SB-366791.

Recombinant peptide derived from the venom the Phoneutria nigriventer spider relieves nociception by nerve deafferentation

The avulsion of nerve roots of the brachial plexus that is commonly seen in motorcycle accidents is a type of neuropathy due to deafferentation. This type of pain is clinically challenging since therapeutical protocols fail or have severe side effects. Thus, it is proposed to evaluate the antinociceptive activity of the recombinant CTK 01512-2 peptide that is derived from the venom of the Phoneutria nigriventer spider, as a future new therapeutical option. The neuropathic pain was surgically induced by avulsion of the upper brachial plexus trunk in groups of male Wistar rats and after 17 days, they were treated intrathecally with morphine, ziconotide, and CTK 01512-2. Behavioral tests were performed to evaluate mechanical and thermal hyperalgesia, cold allodynia, the functional activity of the front paw, and exploratory locomotion after the treatments. The peripheral blood samples were collected 6 h after the treatments and a comet assay was performed. The spinal cord was removed for the lipoperoxidation dosing of the membranes. The cerebrospinal fluid was analyzed for the dosage of glutamate. The recombinant peptide showed an antinociceptive effect when compared to the other drugs, without affecting the locomotor activity of the animals. Mechanical and thermal hyperalgesia, as well as cold allodynia, were reduced in the first hours of treatment. The levels of glutamate and the damage by membrane lipoperoxidation were shown to be improved, and genotoxicity was not demonstrated. In a scenario of therapeutical failures in the treatment of this type of pain, CTK 01512-2 was shown as a new effective alternative protocol. However, further testing is required to determine pharmacokinetics.

Anti-hyperlipidemic effects of Campomanesia xanthocarpa aqueous extract and its modulation on oxidative stress and genomic instability in Wistar rats

The use of natural products from herbs may be a therapeutic option in dyslipidemia treatment. Campomanesia xanthocarpa (Mart.) O. Berg (Myrtaceae) leaves have been used to decrease cholesterol levels. However, studies to determine activities of this plant on triglycerides metabolism have received little attention. The aim of this study was to examine anti-hyperlipidemic effects of a C. xanthocarpa aqueous leaf extract (CxAE) and assess protective actions against oxidative stress and DNA damage. The tyloxapol-induced hyperlipidemia model was used in Wistar rats. Rats were treated orally with CxAE either 250 or 500 mg/kg/day for 7 days prior to tyloxapol administration. Biochemical parameters, oxidative stress levels, and genomic instability were assessed in several tissues. CxAE decreased cholesterol and triglyceride levels in serum and hepatic and renal DNA damage in tyloxapol-treated rats. There was no marked effect on the micronucleus frequency in bone marrow. The extract increased catalase activity and decreased glutathione S-transferase activity in kidney tissue. CxAE showed anti-hyperlipidemic effects, improved oxidative parameters, and protected DNA against damage induced by tyloxapol-induced hyperlipidemia, suggesting C. xanthocarpa leaves may be useful in preventing dyslipidemias.Abbreviations: ALP: Alkaline phosphatase; ALT: Aspartate aminotransferase; ANOVA: Analysis of variance; AST: Aspartate aminotransferase; Ator: Atorvastatin; CAT: Catalase; Chol: Cholesterol; CxAE: Campomanesia xanthocarpa aqueous extract; GST: Glutathione S-transferase; HDL: High density cholesterol; i.p.: Intraperitoneal; NCE: Normochromatic erythrocyte; PBS: Phosphate buffer solution; PCE: Polychromatic erythrocyte; ROS: Reactive oxygen species; SD: Standard deviation; SOD: Superoxide dismutase; T: Tyloxapol; TBARS: Thiobarbituric acid reacting substances; TG: Triglyceride.

Antigenotoxic and antimutagenic effects of Myrciaria dubia juice in mice submitted to ethanol 28-day treatment

Myrciaria dubia is a native plant from the Amazon region which produces red-purplish fruit rich in antioxidant compounds such as ascorbic acid, carotenoids, and phenolic. M. dubia fruit is used to prepare juices considered to possess high nutritional content providing health benefits. The aim of this study was to examine the ability of M. dubia juice to protect DNA against genomic instability induced by sub-acute ethanol consumption attributed to oxidative stress. Mice were treated for 28 days with juice at 25% and 50% diluted in distilled water or with the diluted combination juice plus ethanol (5 g/kg). The genotoxic/antigenotoxic and mutagenic/antimutagenic effects were assessed using comet assay in blood, liver, and kidney and micronucleus (MN) test with bone marrow. In addition, the mutagenicity was also evaluated using Salmonella/microsome assay. Phytochemical compounds were determined using HPLC/PDA/MS/MS. The juice did not induce genotoxic effects in blood, kidney, and liver cells at both doses. In combination with ethanol, the juice reduced the alcohol-mediated DNA damage in all tissues analyzed. Further, the juice did not produce mutagenic effects and decreased mutagenicity induced by ethanol in the bone marrow. The anthocyanins were major compounds detected by HPLC/PDA/MS/MS, which modulated genotoxic and mutagenic effects initiated by ethanol and at least in part appeared responsible for the observed antigenotoxic and antimutagenic effects of M. dubia juice.

Carboxyethyl aminobutyric acid (CEGABA) lacks cytotoxicity and genotoxicity and stimulates cell proliferation and migration in vitro

Cosmeceuticals are cosmetics formulated using compounds with medical-like benefits. Though the antiaging effect of carboxyethyl aminobutyric acid (CEGABA) has been discussed, its action mechanism in cosmeceuticals remains unclear. This study assessed the in vitro efficacy and safety of CEGABA. NHI-3T3 mouse fibroblast cell line was treated with two CEGABA concentrations (50 and 500 μmol/L) for 24 h, 48 h, and 72 h. Cytotoxicity and genotoxicity were evaluated by colorimetry (MTT) and the alkaline version of the comet assay, respectively. Flow cytometry and the scratch-wound assay were used to assess cell-cycle phase distributions and cell migration rates. Compared with the untreated control, CEGABA increased cell growth 1.6 times after 72 h, independent of dose. The compound also decreased cell replication time by 4 h. These findings seem to be related with the approximately 1.5-times increase in phase S cells numbers. Importantly, in vitro wound healing improved roughly 20% after treatment with CEGABA for 24 h and persisted after 48 h, indicating culture recovery. The time-dependent proliferation and migration of fibroblasts induced by CEGABA besides the fact that the compound is neither genotoxic nor cytotoxic makes it an ideal candidate in the development of cosmeceuticals in antiaging therapy.

Toxicological aspects of Campomanesia xanthocarpa Berg. associated with its phytochemical profile

Campomanesia xanthocarpa leaves are used as tea to treat diarrhea, inflammation, and hypercholesterolemia. Some pharmacological studies noted its beneficial uses of C. xanthocarpa; however, few investigations examined the toxicological profile of this plant. The aim of this study was to determine the chemical composition, genotoxic, and mutagenic potential of an aqueous extract of C. xanthocarpa leaves (CxAE), and potential protective effects against oxidative damage. Phytochemical constituents were determined using HPLC, and antioxidant effect in vitro was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. Genotoxic effects and chromosomic mutations were assessed using comet assay and micronucleus (MN) test in Wistar rats treated with CxAE at 250, 500 or 1000 mg/kg for 7 consecutive days. Lipid peroxidation and antioxidant enzyme activities were measured in several tissues. CxAE induced mutations in TA98, TA97a, and TA102 strains. However, in the presence of metabolic activation, data were negative for all strains tested. Lack of mutagenicity was also observed in the MN test. This extract did not induce DNA damage, except when the highest concentration was used. DNA oxidative damage induced by hydrogen peroxide (H₂O₂) decreased in blood after treatment with CxAE. Lipid peroxidation levels were reduced while superoxide dismutase (SOD) activity increased in kidneys. The inhibitory concentration of CxAE required to lower DPPH levels to 50% was 38.47 ± 2.06 μg/ml. In conclusion, frameshift and oxidative mutations were observed only in the absence of metabolic activation which may be attributed to the presence of flavonoids such as quercetin. It is of interest that CxAE also showed protective effects against DNA oxidative damage associated with presence of ellagic acid, a phenolic acid with antioxidant activities. CxAE did not induce in vivo mutagenicity, suggesting that this extract poses a low toxic hazard over the short term.

Amido Black 10B a widely used azo dye causes DNA damage in pro- and eukaryotic indicator cells

Acid Black 10B (AB10B) is widely used for the production of textiles, leather and prints. It is a representative of azo dyes and it is well documented that some of these compounds are mutagenic per se, and that cleavage products (in particular aromatic amines) may cause damage of the genetic material and cancer. Since no toxicological data on AB10B have been published, we evaluated its mutagenic activity in Salmonella/microsome assays and studied its acute toxic and genotoxic properties in a human derived liver cell line (HepG2) which retained the activities of drug metabolizing enzymes. The compound did not cause cytotoxicity (MTT assay), but clear genotoxic effects were detected in pro- and eukaryotic indicator cells. Dose dependent induction of his⁺ revertants was seen in strain TA98 which detects frameshift mutations without metabolic activation; a more pronounced effect was seen in its derivative YG1024 which overexpresses N-acetyltransferase. Induction of single/double strand breaks by Comet assay was detected with concentrations > 0.125 mg/mL in liver derived cells; as well as increased rates for micronucleus (reflecting structural and numeric chromosomal aberrations) and nuclear buds which are a consequence of gene amplifications were seen with a higher dose (2.0 mg/mL) (p < 0.05; Tukey's test). The mutational pattern which was observed in the bacterial tests indicates that the cleavage product p-nitroaniline may cause the genotoxic effects of the dye. Our findings indicate that exposure of humans and the release of the compound into the environment may lead to adverse effects due to its DNA damaging activity.

Toxicological evaluation of a standardized hydroethanolic extract from leaves of Plantago australis and its major compound, verbascoside

ETHNOPHARMACOLOGICAL RELEVANCE

Plantago australis is a perennial plant widely distributed in Latin America, and its seeds and leaves are used in folk medicine to treat many diseases and conditions. Among its various chemical compounds, verbascoside is one of the most present, and has several pharmacological activities described, but there is not much information about its toxicity.

AIMS OF THE STUDY

The aims of this study were to optimize the extraction of verbascoside from P. australis leaves with ultrasound methods, to develop a validated HPLC method to quantify verbascoside, and to evaluate the toxicological safety of the extract and verbascoside using in vitro and in vivo assays.

MATERIALS AND METHODS

Dried leaves of P. australis were submitted to different extraction methods (percolation and ultrasound). The optimization of the ultrasound extraction was carried out by complete factorial design (2²) and response surface methodology (RSM), followed by HPLC analysis for marker compounds. HPLC analysis was performed to verify the presence of the marker compounds aucubin, baicalein, oleanolic acid, ursolic acid and verbascoside. Mutagenicity was assessed by Salmonella/microsome mutagenicity assay. Cytotoxicity and genotoxicity were evaluated in V79 cells by reduction of tetrazolium salt (MTT) and neutral red uptake (NRU) assays, and alkaline comet assay, respectively. Verbascoside phototoxicity was assessed in 3T3 cells by the NRU phototoxicity assay. Wistar rats were used to perform the acute and sub-chronic toxicity tests.

RESULTS

Among the marker compounds, only verbascoside was found in the hydroethanolic extract of P. australis leaves (PAHE); its highest concentration was obtained with the ultrasound-assisted extraction (UAE) method, optimized in 40 min and 25 °C, and the method validation was successfully applied. Neither PAHE nor verbascoside showed mutagenic or genotoxic activities. Cytotoxicity assays demonstrated that both PAHE and verbascoside reduced cell viability only at the highest concentrations, and verbascoside had no phototoxic properties. The in vivo toxicity evaluation of PAHE suggested that the LD50 is higher than 5000 mg/Kg, indicating that this extract is safe for use. In addition, no signs of toxicity were found in subchronic exposure.

CONCLUSION

The HPLC method to quantify verbascoside was validated, and the extraction of verbascoside from P. australis leaves through ultrasound method was optimized, yielding an extract with 6% verbascoside. Our results suggest the toxicological safety of PAHE and verbascoside, corroborating the use of P. australis in folk medicine, and also indicate verbascoside as a potential ingredient in topical formulations.

Nutritional composition of Eragrostis teff and its association with the observed antimutagenic effects

Eragrostis teff is an Ethiopian native grass plant (Poaceae or Gramineae family) whose importance as a crop grain has increased in recent years. The aim of this study is to analyze the nutritional composition of its seeds and the mutagenic/antimutagenic activity of the hydroalcoholic extract of the seed flour. Chemical elements (colloquially known as minerals) were determined using Particle-Induced X-ray Emission (PIXE) and Flame Atomic Absorption Spectroscopy (FAAS), while the content of amino acids (aminogram) and fatty acids (profile of fatty acids) were quantified by HPLC. Mutagenic activities were tested using Salmonella/microsome assay. Mutagens doxorubicin, 4-nitroquinolin N-oxide, methylmethanosulphonate, and aflatoxin B-1 were used in Salmonella typhimurium TA98 and TA100 strains to assess antimutagenic activities. The major elements observed were K, P, S, Mg, and Ca. Almost all essential amino acids were observed and the predominance of unsaturated fatty acids in the total oil content of 2.72% (w/w) is also noted, including the two essential fatty acids alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid). Hydroalcoholic extract of E. teff seed flour showed antimutagenic activity, protecting against frameshift and base pair substitution mutations. These findings provide valuable information for further development of healthier foods that can be produced with increasing yields and minimal environmental impact.

Eragrostis teff is an Ethiopian native grass plant (Poaceae or Gramineae family) whose importance as a crop grain has increased in recent years.

Gamma-Decanolactone Improves Biochemical Parameters Associated with Pilocarpine-Induced Seizures in Male Mice

BACKGROUND AND OBJECTIVE

Gamma-decanolactone (GD) is a monoterpene effective against seizures induced by pentylenetetrazole. The mechanism of action of GD is likely to be via glutamate antagonism. GD also inhibits intracellular reactive oxygen species (ROS) generation and the lipopolysaccharide-induced expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α) in vitro. Considering the neuropharmacological profile of GD studied so far, we investigated the effect of intraperitoneal administration of GD 100 and 300 mg/kg on pilocarpine (PIL)-induced status epilepticus (SE) in mice.

METHODS

GD was administered 30 min before PIL. Behavioral (latency to first seizure and the percentage of clonic forelimb seizures), biochemical, and oxidative stress parameters were evaluated. DNA damage in the cerebral cortex of mice was assessed using the comet assay and mutagenic activity of GD was evaluated using Salmonella/microsome assay in TA100, TA98, TA97a, TA102, and TA1535 strains, with and without metabolic activation (S9 mix).

RESULTS

The behavioral results showed that only the latency to the first clonic seizure increased in the groups treated with GD 300 mg/kg, but not when the animals received GD 100 mg/kg. Both GD doses were able to increase superoxide dismutase and catalase activities, inducing a decrease in ROS and nitrite production and in DNA damage in the cerebral cortex. GD was not able to induce base pair substitution and frameshift mutations in the absence or in the presence of metabolic activation.

CONCLUSION

These findings demonstrate that GD does not improve behavioral parameters in the PIL model, but it was able to protect seizure-related oxidative stress and DNA damage in mice, without inducing gene mutations.

Evaluation of DNA damage in spinal cord and mutagenic effect of a Phα1β recombinant toxin with analgesic properties from the Phoneutria nigriventer spider

Phα1β peptide isolated from the venom of the Phoneutria nigriventer spider has shown higher analgesic action in pre-clinical studies than ω-conotoxin MVIIA peptide used to treat severe chronic pain. In view of the great potential for the development of a new Phα1β-based drug, a Phα1β recombinant form (CTK 01512-2) has been studied for efficacy and safety. The aim of this study was to evaluate cytotoxic, genotoxic and mutagenic effects of a Phα1β recombinant form and compare it with native Phα1β and ω-conotoxin MVIIA. Cytotoxicity was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) colourimetric assay in L929 mouse fibroblast cells (0.5-10.0 μmol/L). Genotoxic and mutagenic activities were analysed using the alkaline comet assay in peripheral blood and spinal cord, and the micronucleus test in bone marrow from Wistar rats treated by intrathecal injection of CTK 01512-2 (200, 500 and 1000 pmol/site), native Phα1β (500 pmol/site) and ω-conotoxin MVIIA (200 pmol/site). CTK 01512-2 decreased the cell viability of the L929, showing IC₅₀ of 3.3 ± 0.1 µmol/L, while the Phα1β and ω-conotoxin MVIIA did not show cytotoxicity (IC₅₀  > 5.0 µmol/L). Native and recombinant Phα1β forms induced DNA damage in the spinal cord, but not in peripheral blood. CTK 01512-2 at 1000 pmol/site increased the micronucleus frequency suggesting mutagenic effects. In conclusion, the recombinant form has cytotoxic, genotoxic and mutagenic effects, evidenced in doses five times above the therapeutic dose.

Persistent Increased Frequency of Genomic Instability in Women Diagnosed with Breast Cancer: Before, during, and after Treatments

This study aimed to evaluate DNA damage in patients with breast cancer before treatment (background) and after chemotherapy (QT) and radiotherapy (RT) treatment using the Comet assay in peripheral blood and the micronucleus test in buccal cells. We also evaluated repair of DNA damage after the end of RT, as well as the response of patient's cells before treatment with an oxidizing agent (H2O2; challenge assay). Fifty women with a mammographic diagnosis negative for cancer (control group) and 100 women with a diagnosis of breast cancer (followed up during the treatment) were involved in this study. The significant DNA damage was observed by increasing in the index and frequency of damage along with the increasing of the frequency of micronuclei in peripheral blood and cells of the buccal mucosa, respectively. Despite the variability of the responses of breast cancer patients, the individuals presented lesions on the DNA, detected by the Comet assay and micronucleus Test, from the diagnosis until the end of the oncological treatment and were more susceptible to oxidative stress. We can conclude that the damages were due to clastogenic and/or aneugenic effects related to the neoplasia itself and that they increased, especially after RT.

DNA damage and oxidative stress induced by seizures are decreased by anticonvulsant and neuroprotective effects of lobeline, a candidate to treat alcoholism

The alkaloid lobeline (Lob) has been studied due to its potential use in treatment of drug abuse. This study evaluates the possible anticonvulsant and neuroprotective activities of Lob to obtain new information on its properties that could confirm it as a candidate in the treatment of alcohol addiction. The anticonvulsant effect of Lob was evaluated using a pilocarpine-induced seizure model. In addition, possible neuroprotective effects were investigated measuring DNA damage using the comet assay, assessing free radical levels by dichlorofluorescein diacetate (DCF) oxidation, and measuring the antioxidant potential using the α, α-diphenyl-β-picrylhydrazyl (DPPH) scavenging assay, besides measuring superoxide dismutase (SOD) and catalase (CAT) enzyme activities in brain tissues. Lobeline increased the latency to the first seizure and decreased the percentage of seizures in a similar way as diazepam, used as control. DNA damage induced by Pil and hydrogen peroxide were decreased in hippocampus and cerebral cortex from mice treated with Lob. The levels of free radicals and CAT activity increased in cortex and hippocampus, respectively, in mice treated with Pil. Lobeline decreased CAT in hippocampus, leading to similar values as in the saline negative control. In conclusion, Lob has anticonvulsant and neuroprotective actions that may be mediated by antioxidant-like mechanisms, indicating its potential as candidate drug in alcoholism therapy.

Ductular reaction, cytokeratin 7 positivity, and gamma-glutamyl transferase in multistage hepatocarcinogenesis in rats

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and is characterized by multistage formation. The presence of ductular reaction, cytokeratin 7 positivity (PCK7), and increased levels of gamma glutamyltransferase (γGT) has been observed during liver carcinogenesis and contribute to tumor progression. Our goal was to evaluate the ductular reaction in multistage carcinogenesis and to correlate PCK7 and γGT levels with tumor incidence, histological characteristics, liver DNA damage index, and the expression of oxidative stress proteins. HCC was induced in 24 male Wistar rats weighing 145-150 g by chronic and intermittent exposure to 50 or 100 mg/kg diethylnitrosamine (DEN). Six control animals received only vehicle. Blood was collected to determine hepatic enzyme levels. Animals were divided into three groups: control (CO), precancerous lesions (PL), and advanced HCC. Liver samples were obtained for immunohistochemical analyses and the measurement of protein expression. Statistical analyses included Tukey's test and Pearson's correlation analyses. We observed an extensive ductular reaction in advanced HCC and a strong correlation between PCK7 and levels of γGT and the poor prognosis and aggressiveness of HCC. The extent of PCK7 and high γGT levels were associated with overexpression of inducible nitric oxide synthase (iNOS) and heat shock factor protein 1 (HSF-1). However, PCK7 and γGT levels were negatively correlated with protein expression of nuclear factor erythroid 2-related factor 2 (NRF2) and inducible heat shock protein 70 (iHSP70). These findings suggest that ductular reaction is involved in the progression of multistage hepatocarcinogenesis.

Genotoxicity induced by water and sediment samples from a river under the influence of brewery effluent

Brewery effluents contain complex mixtures that are discharged into rivers. Therefore, it is necessary to evaluate the genotoxic potential of these effluents. The study evaluated the genotoxicity of surface water and sediment samples from the Jacuí River in the state of Rio Grande do Sul, Brazil, which received effluents discharged from a brewery. The Salmonella/microsome test, Comet Assay and Micronucleus test on V79 cells, as well as the element profile (PIXE) and PAHs levels were used for this purpose. The surface water and sediment samples were collected in summer at three sites: 1 km upstream from the brewery discharge site (Site A); in front of the effluent discharge site, after chemical and biological treatment (Site B); about 1 km downstream from the discharge site (Site C). Only a sediment sample from Site A induced a mutagenic effect using the Salmonella/microsoma test (TA97a). All three sites presented genotoxicity (A, B and C), both for water and sediments using comet assay, and mutagenicity in the samples from Site B (surface water) and Site A and Site C (sediments) using the micronuclei tests. The results of PIXE and PAHs showed higher levels of elements for samples obtained from sites upstream and downstream from the effluent discharge. Environmental samples consist of complex mixtures of chemicals, and it is difficult to associate DNA damage with a specific element. This study showed that brewery effluent contains metals and PAHs that can induce in vitro genotoxicity under the conditions of this study.

Neurobehavioral effects of vigabatrin and its ability to induce DNA damage in brain cells after acute treatment in rats

RATIONALE

Vigabatrin (VGB) is a drug indicated mostly for the treatment of spasms in childhood and West's syndrome patients. This drug inhibits irreversibly the enzyme GABA-transaminase (GABA-T), increasing GABA concentrations and enhancing GABAergic neurotransmission in the brain, which is known to induce behavioral changes.

OBJECTIVES

The aims of this study were to evaluate the effects of VGB in the short-term memory (STM), long-term memory (LTM), motivation, locomotion, and exploratory behavior tests and to detect deleterious or protective effects on DNA in target tissues of the drug.

METHODS

Male Wistar rats were treated with a single dose of VGB (100, 250, or 500 mg/kg) or saline solution before the inhibitory avoidance and open-field tasks. DNA damage was evaluated using the alkaline comet assay in peripheral blood, cerebral cortex, and hippocampus after behavioral testing.

RESULTS

There was no significant difference in the inhibitory avoidance task between the treated groups and the saline group. In all tested doses, VGB reduced the number of rearings in the open-field task. Besides, VGB 500 mg/kg affected locomotion, though it was not able to induce any DNA damage.

CONCLUSIONS

VGB did not affect STM and LTM, but the drug impaired the exploration and locomotion likely associated with its sedative effect. In addition, no DNA damage in cortex and hippocampus was detected after behavioral testing, when brain GABA levels are already increased.

Genotoxic, mutagenic and antigenotoxic effects of Cecropia pachystachya Trécul aqueous extract using in vivo and in vitro assays

ETHNOPHARMACOLOGICAL RELEVANCE

Cecropia pachystachya is a medicinal plant native to South and Central Americas used to treat asthma and diabetes.

AIM OF THE STUDY

In this study, we evaluated the genotoxic, mutagenic and antigenotoxic effects of crude aqueous extract of C. pachystachya (CAE-Cp) leaves.

MATERIAL AND METHODS

CAE-Cp was analyzed by the Folin-Ciocalteu method to determine total phenolic and tannin contents. High performance liquid chromatography (HPLC) was used to identify major compounds. Distinct tissues from female and male adult mice were treated with 500-2000mg/kg of CAE-Cp by gavage for the comet assay and micronucleus test analyses. In addition, peripheral blood slides of the group treated with 2000mg/kg CAE-Cp were analyzed 3, 6, and 24h after treatment and were exposed to hydrogen peroxide (ex vivo) to evaluate the genotoxic effect using the comet assay. The Salmonella/microsome assay was carried out against to TA100, TA98, TA97a, TA102, and TA1535 strains in presence and absence of the S9 mix.

RESULTS

HPLC showed the presence of chlorogenic acid, isoorientin, orientin, and isovitexin as major compounds. Total phenolic and tannin contents were, respectively, 305.6±0.80 and 144.6±19.04mg of gallic acid equivalent/g of extract. Brain DNA damage was observed in all groups treated with CAE-Cp. The H₂O₂ challenge indicated genotoxic effect only 6h after the administration of the extract. No increase was detected in micronucleus frequency for any group treated with the extract. Mutagenic effects were detected by Salmonella/microsome assay only in TA102 strain without S9 mix at higher doses.

CONCLUSION

The results obtained indicate that CAE-Cp was genotoxic to brain tissue. This result is supported by other papers, showing that compounds present in this extract can cross the blood-brain barrier and act on central nervous system.

Behavioral and genotoxic evaluation of rosmarinic and caffeic acid in acute seizure models induced by pentylenetetrazole and pilocarpine in mice

The goal of this study was to investigate the effects of rosmarinic acid (RA) and caffeic acid (CA) in the acute pentylenetetrazole (PTZ) and pilocarpine (PIL) seizure models. We also evaluated the effect of RA and CA on the diazepam (DZP)-induced sleeping time test and its possible neuroprotective effect against the genotoxic damage induced by PTZ and PIL. Mice were treated intraperitoneally (i.p.) with saline, RA (2 or 4 mg/kg), or CA (4 or 8 mg/kg) alone or associated to low-dose DZP. After, mice received a single dose of PTZ (88 mg/kg) or PIL (250 mg/kg) and were monitored for the percentage of seizures and the latency to first seizure (LFS) >3 s. Vigabatrin and DZP were used as positive controls. In the DZP-induced sleeping time test, mice were treated with RA and CA and 30 min after receiving DZP (25 mg/kg, i.p.). The alkaline comet assay was performed after acute seizure tests to evaluate the antigenotoxic profiles of RA and CA. The doses of RA and CA tested alone did not reduce the occurrence of seizures induced by PTZ or PIL. The association of 4 mg/kg RA + low-dose DZP was shown to increase LFS in the PTZ model, compared to the group that received only the DZP. In the DZP-induced sleeping time test, the latency to sleep was reduced by 4 mg/kg RA and 8 mg/kg CA. The PTZ-induced genotoxic damage was not prevented by RA or CA, but the PIL-induced genotoxic damage was decreased by pretreatment with 4 mg/kg RA (in cortex) and 4 mg/kg CA (in hippocampus). In conclusion, RA and CA presented neuroprotective effect against PIL-induced genotoxic damage and reduced the latency to DZP-induced sleep. Of the rosmarinic acid, 4 mg/kg enhanced the DZP effect in the increase of latency to clonic PTZ-induced seizures.

Genotoxic and mutagenic effects of vigabatrin, a γ-aminobutyric acid transaminase inhibitor, in Wistar rats submitted to rotarod task

Vigabatrin (VGB) is an antiepileptic drug thatincreases brain γ-aminobutyric acid (GABA) levels through irreversible inhibition of GABA transaminase. The aim of this study was to evaluate neurotoxicological effects of VGB measuring motor activity and genotoxic and mutagenic effects after a single and repeated administration. Male Wistar rats received saline, VGB 50, 100, or 250 mg/kg by gavage for acute and subchronic (14 days) treatments and evaluated in the rotarod task. Genotoxicity was evaluated using the alkaline version of the comet assay in samples of blood, liver, hippocampus, and brain cortex after both treatments. Mutagenicity was evaluated using the micronucleus test in bone marrow of the same animals that received subchronic treatment. The groups treated with VGB showed similar performance in rotarod compared with the saline group. Regarding the acute treatment, it was observed that only higher VGB doses induced DNA damage in blood and hippocampus. After the subchronic treatment, VGB did not show genotoxic or mutagenic effects. In brief, VGB did not impair motor activities in rats after acute and subchronic treatments. It showed a repairable genotoxic potential in the central nervous system since genotoxicity was observed in the acute treatment group.

Melatonin Activates Endoplasmic Reticulum Stress and Apoptosis in Rats with Diethylnitrosamine-Induced Hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is one of the most lethal human cancers worldwide because of its high incidence, its metastatic potential and the low efficacy of conventional treatment. Inactivation of apoptosis is implicated in tumour progression and chemotherapy resistance, and has been linked to the presence of endoplasmic reticulum stress. Melatonin, the main product of the pineal gland, exerts anti-proliferative, pro-apoptotic and anti-angiogenic effects in HCC cells, but these effects still need to be confirmed in animal models. Male Wistar rats in treatment groups received diethylnitrosamine (DEN) 50 mg/kg intraperitoneally twice/once a week for 18 weeks. Melatonin was given in drinking water at 1 mg/kg/d, beginning 5 or 12 weeks after the start of DEN administration. Melatonin improved survival rates and successfully attenuated liver injury, as shown by histopathology, decreased levels of serum transaminases and reduced expression of placental glutathione S-transferase. Furthermore, melatonin treatment resulted in a significant increase of caspase 3, 8 and 9 activities, polyadenosine diphosphate (ADP) ribose polymerase (PARP) cleavage, and Bcl-associated X protein (Bax)/Bcl-2 ratio. Cytochrome c, p53 and Fas-L protein concentration were also significantly enhanced by melatonin. Melatonin induced an increased expression of activating transcription factor 6 (ATF6), C/EBP-homologous protein (CHOP) and immunoglobulin heavy chain-binding protein (BiP), while cyclooxygenase (COX)-2 expression decreased. Data obtained suggest that induction of apoptosis and ER stress contribute to the beneficial effects of melatonin in rats with DEN-induced HCC.

Evaluation of Safety of Arrabidaea chica Verlot (Bignoniaceae), a Plant with Healing Properties

Arrabidaea chica Verlot (Bignoniaceae) has been used as a medicinal herb to treat anemia, hemorrhage, inflammation, intestinal colic, hepatitis, and skin infections in the Brazilian Amazon region. Studies have demonstrated the healing properties of extracts obtained from A. chica leaves, which contain anthocyanins and flavonoids. However, few investigations have assessed the safe use of this plant species. In this study, mutagenic and genotoxic effects of a crude aqueous extract, a butanolic fraction, and aqueous waste from A. chica leaves were evaluated using the Salmonella/microsome assay in TA98, TA97a, TA100, TA102, and TA1535 strains and the alkaline comet assay in Chinese hamster ovary (CHO) cell culture with and without metabolic activation. The crude aqueous extract, butanolic fraction, and aqueous waste were not mutagenic in any of the Salmonella typhimurium strains tested, and showed negative responses for genotoxicity in CHO cells. High-performance liquid chromatography (HPLC) analysis indicated the presence of phenolic acids and flavonoids such as rutin and luteolin. The lack of mutagenic/genotoxic effects might be due to phytochemical composition with high concentrations of known anti-inflammatory compounds. Thus, the crude aqueous extract, butanolic fraction, and aqueous waste from A. chica leaves do not appear to pose short-term genotoxic risks.

Antiepileptogenic, antioxidant and genotoxic evaluation of rosmarinic acid and its metabolite caffeic acid in mice

AIMS

Antioxidant compounds have been extensively investigated as a pharmacological alternatives to prevent epileptogenesis. Rosmarinic acid (RA) and caffeic acid (CA) are compounds with antioxidant properties, and RA has been shown to inhibit GABA transaminase activity (in vitro). Our aim was to evaluate the effect of RA and CA on seizures induced by pentylenotetrazole (PTZ) using the kindling model in mice.

MAIN METHODS

Male CF-1 mice were treated once every three days during 16days with RA (1, 2 or 4mg/kg; i.p.), or CA (1, 4 or 8mg/kg; i.p.), or positive controls diazepam (1mg/kg; i.p.) or vigabatrin (600mg/kg; p.o.), 30min before PTZ administration (50mg/kg; s.c.). After the last treatment, animals were sacrificed and the cortex was collected to evaluate free radicals (determined by 2',7'-dichlorofluorescein diacetate probe), superoxide dismutase (SOD) and genotoxic activity (Alkaline Comet Assay).

KEY FINDINGS

Rosmarinic acid 2mg/kg increased latency and decreased percentage of seizures, only on the 4th day of observation. The other tested doses of RA and CA did not show any effect. Rosmarinic acid 1mg/kg, CA 4mg/kg and CA 8mg/kg decreased free radicals, but no dose altered the levels of enzyme SOD. In the comet assay, RA 4mg/kg and CA 4mg/kg reduced the DNA damage index.

SIGNIFICANCE

Some doses of rosmarinic acid and CA tested showed neuroprotective action against oxidative and DNA damage produced in the kindling epilepsy model, although they did not produce antiepileptogenic effect in vivo.