Enriching the drinking water of rats with extracts of Salvia officinalis and Thymus vulgaris increases their resistance to oxidative stress.

Nature is an attractive source of therapeutic compounds. In comparison to the artificial drugs, natural compounds cause less adverse side effects and are suitable for current molecularly oriented approaches to drug development and their mutual combining. Medicinal plants represent one of the most available remedy against various diseases.

Assessment of antioxidative, chelating, and DNA-protective effects of selected essential oil components (eugenol, carvacrol, thymol, borneol, eucalyptol) of plants and intact Rosmarinus officinalis oil.

Selected components of plant essential oils and intact Rosmarinus officinalis oil (RO) were investigated for their antioxidant, iron-chelating, and DNA-protective effects. Antioxidant activities were assessed using four different techniques. DNA-protective effects on human hepatoma HepG2 cells and plasmid DNA were evaluated with the help of the comet assay and the DNA topology test, respectively.

Effects of Salvia officinalis and Thymus vulgaris on oxidant-induced DNA damage and antioxidant status in HepG2 cells.

Salvia officinalis (SO) and Thymus vulgaris (TV) are medicinal plants well known for their curative powers. However, the molecular mechanisms responsible for these abilities of sage and thyme have not been fully understood yet. In this study we investigated the composition and the quantitative estimation of plant extracts, the protective effects of plant extracts against hydrogen peroxide- and 2,3-dimethoxy-1,4-naphthoquinone-induced DNA damage, and levels of enzymatic and non-enzymatic antioxidants (superoxide dismutase, glutathione peroxidase, glutathione) in human HepG2 cells.

Comparison of biological processes induced in HepG2 cells by tert-butyl hydroperoxide (t-BHP) and hydroperoxide (H2O2): The influence of carvacrol.

This paper presents comparisons of biological impacts of the oxidants H2O2 and t-BHP on human liver cells, and shows modulation of these effects by the phenolic compound carvacrol. To understand better how these oxidants exert their effect on DNA and on the activity of the enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), we measured intracellular antioxidant glutathione (iGSH) and intracellular reactive oxidative species (iROS). DNA lesions corresponded to single-strand DNA breaks, alkali-labile lesions and formamido-pyrimidine-DNA-glycosylase (FPG)-sensitive sites.

Borneol administration protects primary rat hepatocytes against exogenous oxidative DNA damage.

Experimental evidences suggest that most essential oils possess a wide range of biological and pharmacological activities that may protect tissues against oxidative damage. In this study, we investigated DNA-protective effect of borneol, a component of many essential oils, against oxidative DNA damage induced in primary cultures of rat hepatocytes. Borneol was added to drinking water of Sprague-Dawley rats and DNA resistance against oxidative agents was compared in hepatocytes originated from control and borneol-treated rats.

Carboxymethyl chitin-glucan (CM-CG) protects human HepG2 and HeLa cells against oxidative DNA lesions and stimulates DNA repair of lesions induced by alkylating agents.

A large number of functional foods, including those that contain β-d-glucans, have been shown to prevent human DNA against genotoxic effects and associated development of cancer and other chronic diseases. In this paper, carboxymethyl chitin-glucan (CM-CG) isolated from Aspergillus niger was investigated from two standpoints: (1) DNA-protective effects against oxidative DNA damage induced by H(2)O(2) and alkylating DNA damage induced by MMS and MNNG, and (2) a potential effect on rejoining of MMS- and MNNG-induced single strand DNA breaks. The results obtained by the comet assay in human cells cultured in vitro showed that CM-CG reduced significantly the level of oxidative DNA lesions induced by H(2)O(2) but did not change the level of alkylating DNA lesions induced by MMS or MNNG.

Investigation of anti-oxidative, cytotoxic, DNA-damaging and DNA-protective effects of plant volatiles eugenol and borneol in human-derived HepG2, Caco-2 and VH10 cell lines.

Plant volatiles, which can get into the human organism in food, medicines, or cosmetic preparations, frequently manifest antibacterial, antifungal, antiviral and other effects. We studied anti-oxidative, cytotoxic, genotoxic and possible DNA-protective effects of eugenol and borneol. Anti-oxidative activities of aqueous and ethanolic solutions of these two volatile compounds of plants were determined by a spectrophotometric method by the use of the stable DPPH radical.

Evaluation of genotoxic and cytotoxic effects of H2O2 and DMNQ on freshly isolated rat hepatocytes; protective effects of carboxymethyl chitin-glucan.

Objectives: Utilizing primary rat hepatocytes we investigated the potential antimutagenic and anti-cytotoxic effects of carboxymethyl chitin-glucan (CM-CG) with respect to oxidative stress induced by the model free-radical-generating compounds hydrogen peroxide (H2O2) or 2,3-dimethoxy-1,4-naphthoquinone (DMNQ). Different kinds of CM-CG action were studied by two different treatment protocols: a. pre-incubation of freshly isolated hepatocytes with the potential anti-mutagen followed by exposure to the oxidant or b.

Induction of DNA-lesions in freshly isolated rat hepatocytes by different genotoxins and their reduction by lignin given either as a dietary component or in in vitro conditions.

The aim of our investigation was to verify the protective effect of lignin on DNA in rat hepatocytes damaged by 3 different genotoxins attacking DNA in a different manner. Hydrogen peroxide was used for induction of direct single strand breaks of DNA, visible light-excited methylene blue for induction of oxidized DNA lesions and 1,2-dibromo-3-chloropropane for induction of alkali-labile DNA lesions. Hepatocytes were pre-treated with lignin either immediately after isolation, i.

Effects of dietary intake of a fungal beta-D-glucan derivative on the level of DNA damage induced in primary rat hepatocytes by various carcinogens.

Water-soluble derivative of chitin-glucan complex used in our study, carboxymethyl chitin-glucan (CM-CG), enables oral administration without harmful side-effects, which can occur upon parenteral administration of the insoluble fungal beta-D-glucans. The aim of this study was to determine in ex vivo experiments the effects of dietary CM-CG on the level of DNA lesions in primary rat hepatocytes induced by various indirectly acting carcinogens. Multiorgan carcinogen benzo[a]pyrene (BaP); two hepatocarcinogens, dimethyldibenzocarbazole (diMeDBC) and N-nitrosomorpholine (NMOR); as well as a complex mixture of organic compounds adsorbed on ambient air particles (TP-S) were used for this purpose.

Study of cytotoxic, genotoxic and DNA-protective effects of selected plant essential oils on human cells cultured in vitro.

Objectives: To investigate cytotoxic, genotoxic and DNA-protective effects of carvacrol and thymol on human hepatoma HepG2 and colonic Caco-2 cells cultured in vitro.

Methods And Results: Cytotoxicity testing was performed by the trypan blue exclusion technique. Level of DNA lesions induced in human cells with carvacrol, thymol or their combinations with hydrogen peroxide (H(2)O(2)) were measured by alkaline single cell gel electrophoresis (comet assay).

Protective effects of ursolic acid and oleanolic acid in leukemic cells.

Ursolic acid (UA) and oleanolic acid (OA) have similar chemical structures but differ in the position of one methyl group on the ring E. We investigated protective effects of these two triterpenoic acids against H(2)O(2)-induced DNA damage in leukemic L1210, K562 and HL-60 cells using single-cell gel electrophoresis (SCGE). We compared their protective effects (antioxidant activities) with respect to the different position of the methyl group in their chemical structures.

Comparative evaluation of DNA damage by genotoxicants in primary rat cells applying the comet assay.

Various compounds known to cause DNA damage (hydrogen peroxide, visible light-excited methylene blue, N-nitrosomorpholine and benzo[a]pyrene) were tested with different primary rat cells (lymphocytes, testicular cells, type II pneumocytes and hepatocytes) to determine the range of induced DNA damage applying the comet assay. A dose-dependent increase of DNA breaks was observed after treatment with hydrogen peroxide in all cell types studied. The most prominent effect was observed in lymphocytes, whereas only a slight increase of DNA breaks was observed in hepatocytes.

Nature of DNA lesions induced in human hepatoma cells, human colonic cells and human embryonic lung fibroblasts by the antiretroviral drug 3'-azido-3'-deoxythymidine.

This study tried to clarify the question if nuclear genotoxicity played a role in 3'-azido-3'-deoxythymidine (AZT) toxicity. We investigated cytotoxic and DNA-damaging effects of AZT on human hepatoma HepG2 and human colonic CaCo-2 cells as well as on human diploid lung fibroblasts HEL. The amount of induced DNA damage was measured by standard alkaline single cell gel electrophoresis (SCGE).

Genotoxicity of environmental air pollution in three European cities: Prague, Kosice and Sofia.

The genotoxic potential of extractable organic matter (EOM) associated with the respirable particulate matter (PM <10 microm) of atmospheric pollution has been determined in three European cities--Prague (Czech Republic, two monitoring sites, Libus and Smíchov), Kosice (Slovak Republic) and Sofia (Bulgaria) using the alkaline single-cell gel electrophoresis (the comet assay). The EOM samples were extracted by dichloromethane from ambient airborne particles collected daily (24 h intervals) during 3-month sampling periods in winter and summer seasons. The human metabolically competent cell line Hep G2 was used as a test system and benzo[a]pyrene (BaP), a known carcinogen, was applied as a positive control (internal standard) in each electrophoretic run.

An investigation of the genotoxic effects of N-nitrosomorpholine in mammalian cells.

N-nitrosomorpholine (NMOR) is a well-known hepatocarcinogen. Since this compound is representative of the group of indirect-acting N-nitrosamines, its metabolic activation should be essential. However, the mechanism of NMOR-induced carcinogenesis is still not completely clear.

Cytotoxic and DNA-damaging effects of diterpenoid quinones from the roots of Salvia officinalis L. on colonic and hepatic human cells cultured in vitro.

Three diterpenoid quinones (royleanone- SAR 3, horminone- SAR 26, and acetyl horminone- SAR 43) isolated from the roots of Salvia officinalis L. were tested for their cytotoxic and DNA-damaging activity in human colon carcinoma cells Caco-2 and human hepatoma cells HepG2 cultured in vitro. Cytotoxicity was measured by the trypan blue exclusion technique and induction of apoptosis was evaluated by flow immunofluorocytometry after 30-300 min.

DNA lesions and cytogenetic changes induced by N-nitrosomorpholine in HepG2, V79 and VH10 cells: the protective effects of Vitamins A, C and E.

Introduction: N-Nitrosomorpholine (NMOR), present in the workplace of tyre chemical factories, is a known hepatocarcinogen. This compound belongs to the group of N-nitrosamines, which are indirect-acting and require metabolic activation. However, the mechanism of its carcinogenic effect is not completely clear.

Reduction of genotoxic effects of the carcinogen N-methyl-N'-nitro-N-nitrosoguanidine by dietary lignin in mammalian cells cultured in vitro.

In the present study the protective effect of several lignin polymers against the genotoxic effect of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was tested in hamster lung V79 cells and human colon Caco-2 cells. Preculturing of cells with sublethal, nongenotoxic concentrations of the lignins A, B, and C (50 microg/ml) was found to decrease significantly the level of DNA strand breaks in both hamster and human cells treated with MNNG. Lignin A also reduced MNNG-induced gene mutations in V79 cells.

Genotoxic effects of a complex mixture adsorbed onto ambient air particles on human cells in vitro; the effects of Vitamins E and C.

Genotoxicity of complex mixtures of organic compounds adsorbed onto ambient air particles (extractable organic matter, EOM) collected in Teplice (Czech Republic) as well as genotoxicity of the indirectly acting carcinogens benzo[a]pyrene (B[a]P) and 5,9-dimethyl-7H-dibenzo[c,g]carbazole (5,9-diMeDBC) was studied in human HepG2 and Caco-2 cells cultured in vitro. The level of DNA breaks was detected by conventional single-cell gel electrophoresis (alkaline comet assay). The level of DNA breaks+oxidative DNA lesions was assessed by modified single-cell gel electrophoresis.

Protective effects of fungal (1-->3)-beta-D-glucan derivatives against oxidative DNA lesions in V79 hamster lung cells.

beta-Glucans belong to the class of substances known as biological response modifiers with a broad range of activity. We have investigated two types of glucans: (1-->3)-beta-D glucan from the baker's yeast Saccharomyces cerevisiae and beta-glucan-chitin complex from the mycelium of filamentous fungus Aspergillus niger. Since these fibrillar beta-glucans are insoluble in water, their water-soluble derivatives--carboxymethyl glucan (CM-G), sulfoethyl glucan (SE-G), and carboxymethyl chitin-glucan (CM-CG) were prepared and tested.

Fungal beta-(1-3)-D-glucan derivatives exhibit high antioxidative and antimutagenic activity in vitro.

The antioxidative activity and antimutagenic effects of the water-soluble beta-(1-3)-D-glucan derivatives from biotechnologically important species, in particular carboxymethyl-glucan (CM-G) and sulfoethyl-glucan (SE-G) both from the baker's yeast Saccharomyces cerevisiae, and carboxymethyl-chitin-glucan (CM-CG) from filamentous fungus Aspergillus niger, were evaluated. The luminol-dependent photochemical method using trolox as a standard showed that CM-CG, SE-G and CM-G possessed high antioxidative properties. CM-CG exhibited the highest antioxidative activity (2.

Molecular and cellular influences of butylated hydroxyanisole on Chinese hamster V79 cells treated with N-methyl-N'-nitro-N-nitrosoguanidine: antimutagenicity of butylated hydroxyanisole.

The antioxidant butylated hydroxyanisole (BHA) is a rodent carcinogen that also reduces the mutagenicity and carcinogenicity of other agents. In this study, we have evaluated possible mechanisms for the antimutagenicity of BHA by investigating its effects on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-treated Chinese hamster V79 cells. Mutant frequency was determined using the hprt/V79 assay, while plating efficiency was used to measure cytotoxicity, and apoptosis was measured by flow immunofluorocytometry.

Effect of dietary intake of vitamin A or E on the level of DNA damage, chromosomal aberrations, and micronuclei induced in freshly isolated rat hepatocytes by different carcinogens.

Hepatocytes freshly isolated from male Wistar rats fed a common diet or a vitamin A- or vitamin E-supplemented diet (each for 21, 28, or 41 days) were assayed for sensitivity to DNA breakage and cytogenetic changes induced by carcinogens. Different indirectly acting carcinogens were assayed. N-nitrosomorpholine (NMOR) was the only agent that induced DNA breaks, chromosomal aberrations, and micronuclei in all experiments.

Effects of vitamins C and E on cytotoxicity induced by N-nitroso compounds, N-nitrosomorpholine and N-methyl-N'-nitro-N-nitrosoguanidine in Caco-2 and V79 cell lines.

Since N-nitroso compounds as strong carcinogens are closely related to food and nutrition, the cytotoxic effects of N-nitrosomorpholine (NMOR) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and their reduction by vitamins C and E were investigated in hamster V79 cells and human colon carcinoma Caco-2 cells. Cytotoxicity was evaluated by the trypan blue exclusion technique in Caco-2 cells and by the plating efficiency assay in V79 cells. NMOR caused a dose-dependent decline of viable cells in both cell lines; MNNG induced a dose-dependent cytotoxic effect only in V79 cells.