Cytotoxic and genotoxic potential of geraniol in peripheral blood mononuclear cells and human hepatoma cell line (HepG2).

Geraniol is an acyclic monoterpene alcohol present in the essential oil of many aromatic plants and is one of the most frequently used molecules by the flavor and fragrance industries. The literature also reports its therapeutic potential, highlighting itself especially as a likely molecule for the development of drugs against cancer. In view of these considerations, this study was designed to evaluate the cytotoxic and genotoxic potential of geraniol, in an in vitro protocol, using two types of human cells: one without the ability to metabolize (peripheral blood mononuclear cells - PBMC), and the other with this capability (human hepatoma cell line - HepG2) through the comet assay and the micronucleus test. Four concentrations (10, 25, 50, and 100 µg/mL) were selected for the genotoxic assessment for PBMC and three (1.25, 2.5, and 5 µg/mL) for HepG2 cells based on cytotoxicity tests (MTT assay). Results showed that geraniol did not present genotoxic or clastogenic/aneugenic effects on both cell types under the conditions studied. However, caution is advised in the use of this substance by humans, since a significant reduction in viability of HepG2 and a marked decrease in cell viability on normal PBMC were verified.

First cytotoxic, genotoxic, and antigenotoxic assessment of Euterpe oleracea fruit oil (açaí) in cultured human cells.

Euterpe oleracea Mart., popularly known as "açaí", is a tropical fruit from the Amazon region where it has considerable economic importance. Açaí has been used as food and for several medicinal purposes. Despite the widespread use of this fruit, there is a lack of data regarding the safety of using this fruit oil exclusively. Therefore, we evaluated the in vitro cytotoxic, genotoxic, and antigenotoxic effects of E. oleracea fruit oil (EOO) in cultured human lymphocytes (non-metabolizing cells) and HepG2 cell line (human hepatoma) (metabolizing cells) by using MTT, comet, and micronucleus assays. A wide range of EOO concentrations was tested with a preliminary MTT assay, which allowed selecting five concentrations for comet and micronucleus assays: 2.5, 10, 100, 500, and 1000 µg/mL. The results showed that none of the EOO tested concentrations presented cytotoxic effects. The genotoxic assessment revealed an absence of significant DNA and chromosome damage in human lymphocytes and HepG2 cells but did not show chemoprotection against the DNA damage induced by methyl methanesulfonate and benzo[a]pyrene, used as DNA-damaging agents.

In vitro study of the cytotoxic and genotoxic effects of indomethacin-loaded Eudragit(®) L 100 nanocapsules.

Indomethacin is a non-steroidal anti-inflammatory agent included in one of the most commonly used drug classes worldwide. The use of this drug results in certain side effects, including gastrointestinal complications. Therefore, there exists a need to develop better methods for the delivery of such drugs into the body, such as those employing nanoparticles. The aim of the present study was to evaluate the cytotoxic and genotoxic effects of indomethacin-loaded Eudragit(®) L 100 nanocapsules (NI; based on methacrylic acid and methyl methacrylate) on cells unable (lymphocytes) and able to metabolize drugs (HepG2 cells), using comet and cytokinesis-block micronucleus (CBMN) assays in vitro. Cells were exposed to NI at concentrations of 5, 10, 50, 125, 250, and 500 µg/mL. The comet assay showed that NI induced no significant DNA damage in either cell type at any of the concentrations tested. The CBMN test confirmed these results; however, the highest concentration of 500 µg/mL resulted in a small but statistically significant clastogenic/aneugenic effect in HepG2 cells. These findings should encourage the development of new investigations of this nanomaterial as a delivery vehicle for anti-inflammatory drugs, such as indomethacin.

Evaluation of the genotoxicity of Euterpe oleraceae Mart. (Arecaceae) fruit oil (açaí), in mammalian cells in vivo.

E. oleracea is a tropical plant from the Amazon region, with its fruit used for food, and traditionally, as an antioxidant, anti-inflammatory, hypocholesterolemic, for atherosclerotic disease, and has anticancer properties. The oil of the fruit has antidiarrheic, anti-inflammatory and antinociceptive activities, but without genotoxicity evaluation. Therefore, the aim of this study was to evaluate the genotoxic potential of E. oleracea fruit oil (EOO), in rat cells. Male Wistar rats were treated with EOO by gavage at doses of 30, 100 and 300 mg/kg, for 14 days, within a 24 h interval. The DNA damage in the leukocytes, liver, bone marrow and testicular cells, was assessed by the comet assay, and the clastogenic/aneugenic effects in the bone marrow cells, by the micronucleus test. Our phytochemicals characterization of the EOO showed the presence of vanillic, palmitic, γ-linolenic, linoleic, oleic, cinnamic, caffeic, protocatechuic, ferulic, syringic acids, and flavonoids quercetin and kaempferol rutinoside as the main constituents. Both cytogenetic tests performed showed that EOO presented no significant genotoxic effects in the analyzed cells, at the three tested doses. These results indicate that, under our experimental conditions, E. oleracea fruit oil did not reveal genetic toxicity in rat cells.

Genotoxic evaluation of the antimalarial drugs artemisinin and artesunate in human HepG2 cells and effects on CASP3 and SOD1 gene expressions.

The malaria treatment recommended by the World Health Organization involves medicines derived from artemisinin, an active compound extracted from the plant Artemisia annua, and some of its derivatives, such as artesunate. Considering the lack of data regarding the genotoxic effects of these compounds in human cells, the objective of this study was to evaluate the cytotoxicity and genotoxicity, and expressions of the CASP3 and SOD1 genes in a cultured human hepatocellular liver carcinoma cell line (HepG2 cells) treated with artemisinin and artesunate. We tested concentrations of 2.5, 5, 7.5, 10, and 20 µg/mL of both substances with a resazurin cytotoxicity assay, and the concentrations used in the genotoxicity experiments (2.5, 5, and 10 µg/mL) and gene expression analysis (5 µg/mL) were determined. The results of the comet assay in cells treated with artemisinin and artesunate showed a significant dose-dependent increase (P < 0.001) in the number of cells with DNA damage at all concentrations tested. However, the gene expression analysis revealed no significant change in expression of CASP3 or SOD1. Our data showed that although artemisinin and artesunate exhibited genotoxic effects in cultured HepG2 cells, they did not significantly alter expression of the CASP3 and SOD1 genes at the doses tested.

Genotoxicity of the medicinal plant Maytenus robusta in mammalian cells in vivo.

Plants belonging to the Celastraceae family have been used in traditional medicine for their analgesic, anti-inflammatory and anti-ulcerogenic properties, among others. Maytenus ilicifolia is the principal species of this family, and is used in the treatment of gastric ulcers. However, owing to its inadequate management in Brazil, the species is becoming extinct and is being substituted with Maytenus robusta, which also displays gastroprotective activity. The aim of this study was to evaluate the genotoxic effects of M. robusta hydroalcoholic extract in vivo, using the comet assay and micronucleus test. Three doses (50, 250 and 500 mg/kg body weight) were administered to mice orally 2 times at 24-h intervals. Cytotoxicity was assessed by scoring 200 consecutive total polychromatic and normochromatic erythrocytes to calculate their ratio. Parametric (analysis of variance/Tukey) and non-parametric (Kruskal-Wallis/Dunn post hoc) tests were used to evaluate the results according to the nature of the data distribution. The results showed a significant increase in the frequency of DNA damage on leukocytes at the 2 higher doses tested, but the extract did not enhance micronucleus frequency in bone marrow cells. Our findings showed that after 48 h of treatment, M. robusta hydroalcoholic extract had weak genotoxic effects but no clastogenic effects in mice cells.

In vitro genotoxicity assessment of caffeic, cinnamic and ferulic acids.

Phenols are a large and diverse class of compounds, many of which occur naturally in a variety of food plants; they exhibit a wide range of biological effects, including antibacterial, anti-inflammatory, antiallergic, hepatoprotective, antithrombotic, antiviral, anticarcinogenic, and vasodilatory actions. We examined the genotoxic and clastogenic potential of three phenolic compounds: caffeic, cinnamic and ferulic acids, using the comet and micronucleus assays in vitro. Drug-metabolizing rat hepatoma tissue cells (HTCs) were used. Three different concentrations (50, 500 and 1500 µM) of these phenolic acids were tested on the HTCs for 24 h. The caffeic, cinnamic and ferulic acids were not genotoxic by the comet assay (P > 0.05). However, the micronucleus test showed an increase in the frequency of micronucleated cells for the three compounds, indicating that these substances have clastogenic effects in HTC.

Genotoxicity and mutagenicity of Rosmarinus officinalis (Labiatae) essential oil in mammalian cells in vivo.

Rosmarinus officinalis (rosemary) oil is widely used by the cosmetic, food, and pharmaceutical industries as a fragrance component of soaps, creams, lotions, and perfumes. Although it is popular, potential harmful side-effects of the oil have been described. We investigated the genotoxic and mutagenic potential of essential oil of R. officinalis in rodents, using comet, micronucleus and chromosome aberration assays. The animals were treated by gavage with one of three dosages of rosemary oil (300, 1000 or 2000 mg/kg). Liver and peripheral blood cells were collected from Swiss mice 24 h after treatment for the comet assay (genotoxicity endpoint), along with bone marrow cells for the micronucleus test (mutagenicity endpoint). Bone marrow cells were collected from Wistar rats 24 h after oil treatment for the micronucleus and chromosome aberration assays. Based on the comet assay, all three doses of rosemary oil induced significant increases in DNA damage in the mouse cells. There was a significant increase in micronucleated cells and chromosome aberrations only at the two higher doses. We conclude that rosemary essential oil provokes genotoxic and mutagenic effects when administered orally.

Evaluation of the genotoxic potential of Austroplenckia populnea (Reiss) Lundell chloroform fraction from barkwood extract in rodent cells in vivo.

The genotoxic effect of the Austroplenckia populnea chloroform fraction from barkwood extract was tested in vivo on peripheral blood cells of Swiss mice with the comet assay (SCGE), and the clastogenic effect was investigated on peripheral blood cells of Swiss mice and bone marrow cells of Wistar rats, with the micronucleus and chromosome aberrations tests. The animals were treated by gavage with 3 concentrations of the extract: 300, 600 and 900 mg.kg-1. Peripheral blood cells of Swiss mice were collected 4 and 24 hours after the treatment to the SCGE assay and 48 and 72 hours to the micronucleus test. Bone marrow cells of Wistar rats were collected 24 hours after the treatment to the micronucleus and chromosome aberration tests. The results showed that the A. populnea chloroform fraction induced an increase in the average number of DNA damage in peripheral blood cells at the three concentrations tested, but this increase was not statistically significant. In the micronucleus and chromosome aberrations test, no significant increase was observed in the mean number of micronucleated polychromatic erythrocytes (MNPCE) of Swiss mice or MNPCE or chromosome aberrations for the rat bone marrow cells, for any of the tested doses. Our findings enable us to conclude that by the comet assay, A. populnea chloroform fraction from barkwood extract showed no genotoxic effects, and by the micronucleus and chromosome aberration tests, the extract fraction showed no clastogenic/aneugenic effects on the rodent cells tested.

Assessment of the potential genotoxic risk of medicinal Tamarindus indica fruit pulp extract using in vivo assays.

Tamarindus indica has been used in folk medicine as an antidiabetic, a digestive aid, and a carminative, among other uses. Currently, there is no information in the toxicology literature concerning the safety of T. indica extract. We evaluated the clastogenic and/or genotoxic potential of fruit pulp extract of this plant in vivo in peripheral blood and liver cells of Wistar rats, using the comet assay, and in bone marrow cells of Swiss mice, using the micronucleus test. The extract was administered by gavage at doses of 1000, 1500 and 2000 mg/kg body weight. Peripheral blood and liver cells from Wistar rats were collected 24 h after treatment, for the comet assay. The micronucleus test was carried out in bone marrow cells from Swiss mice collected 24 h after treatment. The extract made with T. indica was devoid of clastogenic and genotoxic activities in the cells of the rodents, when administered orally at these three acute doses.

Genotoxicity testing of Ambelania occidentalis (Apocynaceae) leaf extract in vivo.

Ambelania occidentalis is routinely used in folk medicine for treating gastrointestinal disorders, even though there have been no safety trials. We evaluated the genotoxic potential of hydro-alcoholic extracts of this plant in mice; induced DNA damage was assessed in peripheral blood leukocytes and micronucleus induction was assessed in polychromatic erythrocytes from bone marrow. The extract was administered by an oral route at single doses of 1000, 1500 and 2000 mg/kg body weight. N-nitroso-N-ethylurea was used as a positive control. The comet assay was performed on peripheral blood leukocytes at 4 and 24 h after treatment, and the micronucleus test was carried out on bone marrow cells collected at 24 and 48 h after treatment. The ratio of polychromatic/normochromatic erythrocytes was scored for cytotoxicity assessment. No increase in the number of micronucleated polychromatic erythrocytes from bone marrow or in leukocyte DNA damage was observed. The hydro-alcoholic extracts of A. occidentalis had no mutagenic or cytotoxic effects in the mouse cells.

The mutagenic potential of Clusia alata (Clusiaceae) extract based on two short-term in vivo assays.

We examined the genotoxic and mutagenic effects of a crude extract of Clusia alata (a potential medicinal plant) on peripheral leukocyte and bone marrow cells of mice, using the comet and chromosome aberration assays. Extracts at doses of 1000, 1500 and 2000 mg/kg were administered by gavage, and a positive control, N-nitroso-N-ethylurea (50 mg/kg) was injected intraperitoneally. Peripheral blood leukocytes were collected 4 and 24 h after the treatments for the comet assay, and bone marrow cells were collected 24 h after the treatments, for the chromosome aberration assay. The comet assay showed that C. alata extract causes an increase in damage to DNA in the peripheral blood leukocytes, but it was significant only with the 2000 mg/kg dose after 24 h; the extract also induced a small but significant increase in the mean number of chromosome aberrations in the bone marrow cells at doses of 1500 and 2000 mg/kg. No evidence of a significant decrease in the mitotic index was observed. Acute consumption of high concentrations of C. alata extract produced some mutagenic effects in bone marrow cells.

Mutagenicity of the Musa paradisiaca (Musaceae) fruit peel extract in mouse peripheral blood cells in vivo.

Plants are a source of many biologically active products and nowadays they are of great interest to the pharmaceutical industry. In the present study, the mutagenic potential of the Musa paradisiaca fruit peel extract was assessed by the single-cell gel electrophoresis (SCGE) and micronucleus assays. Animals were treated orally with three different concentrations of the extract (1000, 1500, and 2000 mg/kg body weight). Peripheral blood cells of Swiss mice were collected 24 h after treatment for the SCGE assay and 48 and 72 h for the micronucleus test. The results showed that the two higher doses of the extract of M. paradisiaca induced statistically significant increases in the average numbers of DNA damage in peripheral blood leukocytes for the two higher doses and a significant increase in the mean of micronucleated polychromatic erythrocytes in the three doses tested. The polychromatic/normochromatic erythrocyte ratio scored in the treated groups was not statistically different from the negative control. The data obtained indicate that fruit peel extract from M. paradisiaca showed mutagenic effect in the peripheral blood cells of Swiss albino mice.

Absence of mutagenicity effects of Psidium cattleyanum Sabine (Myrtaceae) extract on peripheral blood and bone marrow cells of mice.

Cattley guava (Psidium cattleyanum Sabine) is a native fruit of Brazil that is popular both as a sweet food and for its reputed therapeutic properties. We examined whether it could damage DNA using the alkaline single-cell gel electrophoresis (comet assay) and the micronucleus test in leukocytes and in bone marrow cells of mice. P. cattleyanum leaf extract was tested at concentrations of 1000, 1500 and 2000 mg/kg. N-nitroso-N-ethylurea was used as a positive control. Peripheral blood leukocytes were collected 4 and 24 h after the treatments for the comet assay, and bone marrow cells were collected after 24 and 48 h for the micronucleus test. Unlike N-nitroso-N-ethylurea, P. cattleyanum extract failed to induce a significant increase in cell DNA damage, in micronucleated cell frequency, and in bone marrow toxicity. The lack of mutagenicity and cytotoxicity with high doses of this plant extract means that it can be safely used in traditional medicine.

Lack of clastogenic/genotoxic effects of Baccharis dracunculifolia extract on Swiss mouse peripheral blood cells.

Baccharis dracunculifolia De Candole (DC) (Asteraceae) is indigenous throughout southeastern Latin America and is used by local people in traditional medicine. This plant is known to be the source of resin for the highly valued Brazilian green propolis. As no information is available on the safety of high doses of B. dracunculifolia extract, we evaluated the mutagenic potential of high doses of this plant extract in vivo on peripheral blood cells of Swiss mice using the comet assay and the micronucleus test. The extract was administered by gavage at doses of 1000, 1500 and 2000 mg/kg body weight. Peripheral blood cell samples were collected 4 and 24 h after treatment for the comet assay (genotoxicity assay), and at 48 and 72 h for the micronucleus test (clastogenicity assay). The B. dracunculifolia extract was devoid of clastogenic/genotoxic activity at all doses.

Evaluation of the genotoxic potential of the Casearia sylvestris extract on HTC and V79 cells by the comet assay.

Casearia sylvestris is common in tropical America growing wild in Brazil in the states of Amazonas and São Paulo. Its leaves are used in Brazilian folk medicine for several diseases. The present investigation was carried out to examine the genotoxic effects of a C. sylvestris crude ethanolic extract on Hepatoma Tissue Culture (HTC cells) of Rattus norvegicus and Chinese hamster V79 cells in culture, using the comet assay. For the genotoxic evaluation the cells were treated with three different concentrations (0.5, 1 and 2 mg/ml) of extract prepared from a 25 mg/ml aqueous solution. The positive control was cyclophosphamide for HTC cells and methyl methanesulfonate for V79 cells. The duration of the treatment was 2 h. The results showed that the extract of C. sylvestris presented no genotoxic effects and not modified effect inducing DNA damage by alkylating agents cyclophosphamide and methyl methanesulfonate in HTC and V 79 cells respectively.

Cytogenetic analysis of A- and B-chromosomes of Prochilodus lineatus (Teleostei, Prochilodontidae) using different restriction enzyme banding and staining methods.

Different cytogenetic techniques were used to analyse the chromosomes of Prochilodus lineatus with the main objective of comparing the base composition of A- and B-chromosomes. The results of digestion of chromosomes with 10 different restriction endonucleases (REs), silver staining, CMA3 staining and C-banding indicated the existence of different classes of highly repetitive DNA in the A-set and also suggested the existence of compositional differences between the chromatin of A- and B-chromosomes. The 5-BrdU incorporation technique showed a late replicating pattern in all B-chromosomes and in some heterochromatic pericentromeric regions of A-chromosomes. The cleavage with RE BamHI produced a band pattern in all chromosomes of P. lineatus which permitted the tentative pairing of homologues in the karyotype of this species. We concluded that the combined use of the above techniques can contribute to the correct identification of chromosomes and the karyotypic analysis in fishes. On the basis of the results, some aspects of chromosome structure and the origin of the B-chromosomes in P. lineatus are discussed.

Cytogenetic characterization of a supernumerary chromosome segment and of B-chromosomes in Astyanax scabripinnis (Teleostei, Characidae).

The chromosome complement of a local population of Astyanax scabripinnis in Brazil was investigated with emphasis on the study of the heterochromatin attached to the A-chromosomes and present in the macro B-chromosome. Analysis after C-banding, silver and CMA3 staining, incorporation of 5-bromo-2'-deoxyuridine and chromosome digestion with nine restriction endonucleases revealed that the heterochromatin in the B-chromosomes was different from that found in the A-chromosomes. A polymorphism due to the presence of a supernumerary heterochromatic chromosome segment was observed in the population investigated. Some aspects related to the origin of the heterochromatin polymorphism in Astyanax scabripinnis are discussed.

Unusual occurrence of a ZZ/ZW sex-chromosome system and supernumerary chromosomes in Characidium cf. fasciatum (Pisces, Characiformes, Characidiinae).

Individuals of two populations of the fish Characidium cf. fasciatum were cytogenetically studied and showed a basic diploid number of 50 chromosomes. Some fishes were found to have 51 to 54 chromosomes due to the presence of one to four small subtelocentric/acrocentric supernumerary chromosomes. When analyzed by conventional Giemsa staining, male and female specimens of C. cf. fasciatum from the Quinta stream and Pardo River presented the same basic karyotypic macro- and microstructure, consisting of 32 metacentric and 18 submetacentric chromosomes. Ag-NORs were terminally located on the long arms of two submetacentric chromosome pairs. Constitutive heterochromatin was identified by C-banding as small pericentromeric blocks in the majority of the chromosomes, and B-chromosomes were found to be heterochromatic. The occurrence of one totally heterochromatic submetacentric chromosome restricted to females and considered as an unusual feature in fish karyotypes led to the identification of a ZZ/ZW sex-chromosome system. The implications of chromosomic differentiation observed in the genus Characidium are discussed.