Chemoprotective effects of captopril against cyclophosphamide-induced genotoxicity in mouse bone marrow cells

The protective effects of captopril (CAP) against toxicity induced by cyclophosphamide (CP) in mice were investigated using the micronucleus assay for anticlastogenic activity in mouse bone marrow cells and liver glutathione (GSH) content. A single intraperitoneal (i.p.) injection of CAP at 50, 100, and 200 mg/kg 1 h prior to cyclophosphamide (50 mg/kg) reduced the frequency of micronucleated polychromatic erythrocytes (MnPCEs). All three doses of CAP significantly reduced the frequency of MnPCEs in mouse bone marrow compared to the group treated with CP alone (P<0.0001–0.01). CP significantly depleted the GSH content in liver but the application of CAP at a dose of 100 mg/kg 1 h before CP treatment repleted the GSH content. CAP exhibited concentration-dependent antioxidant activity, scavenging >96% of the 1,1-diphenyl-2-picryl hydrazyl free radicals when used at a concentration of 0.2 mM. It appears that CAP, due to its antioxidant activity and by increasing GSH levels, can modulate the reduced cellular thiol content induced by CP and reduce the genotoxicity of CP in bone marrow cells.     

Fluoride-induced genotoxicity in mouse bone marrow cells: effect of buthionine sulfoximine and N-acetyl-L-cysteine

A significant level of reactive oxygen species generation was observed in sodium fluoride (NaF) treated mouse bone marrow cells (BMCs). Reduced glutathione (GSH) as a free radical scavenger could be an important determining factor in F‐induced genotoxicity. We therefore attempted to monitor GSH to understand the mechanism of NaF‐induced genotoxicity. NaF was injected intra‐peritoneally in normal, buthionine sulfoximine (BSO) or N‐acetyl‐ l ‐cysteine (NAC) treated mice (n = 5). After 13 h of NaF‐treatment BMCs were collected to harvest them at the same divisional cycle and processed for analysis of cell cycle, induction of apoptosis and chromosomal aberrations (CAs). Level of GSH was also measured concomitantly. NaF induced significant CAs in all treatment groups except at 2.5 mg NaF kg^?1 body weight. BSO‐treatment alone induced significantly high frequency of CAs. BSO treatment prior to injection of 2.5–7.5 mg NaF kg^?1 b.w. was found to increase the frequency of CAs, significantly when compared with the positive control group, but the level was not significant in case of higher doses of NaF treatment (15 and 30 mg kg^?1 b.w.). NaF‐treated cells also showed a higher population of Annexin‐V positive cells. NAC pre‐treatment significantly reduced the extent of NaF‐induced CAs, which clearly indicates the involvement of GSH in the NaF response. However, further study is warranted to evaluate the low synergistic effect of BSO on higher doses of NaF‐induced CAs. Copyright © 2010 John Wiley & Sons, Ltd.     

Protective effect of hawthorn extract against genotoxicity induced by cyclophosphamide in mouse bone marrow cells

The preventive effect of hawthorn (Crataegus microphylla) fruit extract was investigated in mouse bone marrow cells against genotoxicity induced by cyclophosphamide. Mice were orally (gavages) pretreated with solutions of hawthorn extract which was prepared at five different doses (25, 50, 100, 200 and 400mg/kg b.w.) for seven consecutive days. Mice were injected intraperitoneally on the seventh day with cyclophosphamide (50mg/kg b.w.) and killed after 24h for the evaluation of micronucleated polychromatic erythrocytes (MnPCEs) and the ratio of PCE/(PCE+NCE) (polychromatic erythrocyte/polychromatic erythrocyte+normochromatic erythrocyte). All of five doses of extract significantly reduced MnPCEs induced by cyclophosphamide (P<0.0001). Hawthorn extract at dose 100mg/kg b.w. reduced MnPCEs 2.5 time and also completely normalized PCE/(PCE+NCE) ratio. Hawthorn extract exhibited concentration-dependent antioxidant activity on 1,1-diphenyl-2-picryl hydrazyl free radical. Hawthorn contains high amounts of phenolic compounds; the HPLC analysis showed that it contained chlorogenic acid, epicatechin and hyperoside. It is obvious that hawthorn, particularly flavonoids constituents with antioxidative activity, reduced the oxidative stress and genotoxicity induced by cyclophosphamide in mouse bone marrow cells.     

Reduction in fluoride-induced genotoxicity in mouse bone marrow cells after substituting high fluoride-containing water with safe drinking water

Treatment of mice with 15 mg l^?1 sodium fluoride (NaF) for 30 days increased the number of cell death, chromosomal aberrations (CAs) and ‘cells with chromatid breaks’ (aberrant cells) compared with control. The present study was intended to determine whether the fluoride (F)‐induced genotoxicity could be reduced by substituting high F‐containing water after 30 days with safe drinking water, containing 0.1 mg F ions l^?1. A significant fall in percentage of CAs and aberrant cells after withdrawal of F‐treatment following 30 days of safe water treatment in mice was observed which was highest after 90 days, although their levels still remained significantly high compared with the control group. This observation suggests that F‐induced genotoxicity could be reduced by substituting high F‐containing water with safe drinking water. Further study is warranted with different doses and extended treatment of safe water to determine whether the induced damages could be completely reduced or not. Copyright © 2011 John Wiley & Sons, Ltd.     

Investigation of flurbiprofen genotoxicity and cytotoxicity in rat bone marrow cells

This study was performed to investigate cytogenetic effects of NSAID flurbiprofen which was used as active ingredient in some analgesic, antipyretic and anti-inflammatory drugs. Genotoxic effect of flurbiprofen was investigated using in vivo chromosome aberration (CA) test and random amplified polymorphic DNA–polymerase chain reaction (RAPD-PCR) test. Also, oxidative stress potential of flurbiprofen was determined by measuring total oxidant and antioxidant level which occurred with flurbiprofen treatment in rat peripheral blood. For these purposes, rats were treated with three concentrations of flurbiprofen (29.25, 58.50 and 117?mg/kg, body weight) in single dose at two different treatment periods (12 and 24?h). According to the results, flurbiprofen did not affect chromosome aberrations in rat bone marrow cells with CA test. In RAPD-PCR test, polymorphic bands were unaffected. Also, test substance did not change total oxidant and antioxidant status (except for 58.50 and 117?mg/kg, 12?h) and therefore it did not lead to significant increase on oxidative stress (again except 58.50 and 117?mg/kg, 12?h). However, flurbiprofen reduced to mitotic indexes and these reductions were dose-dependent for 12?h treatment. In summary, flurbiprofen did not show significant genotoxic effect. But it caused cytotoxicity in rat bone marrow cells.     

Differential in vivo genotoxicity of arsenic trioxide in glutathione depleted mouse bone marrow cells: expressions of Nrf2/Keap1/P62

Abstract

Generation of reactive oxygen species is one of the major contributors in arsenic-induced genotoxicity where reduced glutathione (GSH) could be an important determining factor. To understand the role of endogenous GSH, arsenic trioxide (As₂O₃) was administered in buthionine sulfoximine (BSO)- and N-acetyl-l-cysteine (NAC)-treated mice. As₂O₃-induced significant chromosome aberrations (CAs) in all treatment groups compared with the control. BSO-treated mouse bone marrow cells showed significant CAs at a dose of 2?mg As₂O₃?kg^?1 b.w. Similar induction was not evident at 4?mg As₂O₃?kg^?1 b.w. and exhibited antagonistic effect at 8?mg As₂O₃?kg^?1 b.w. To understand this differential effect, expression pattern of Nrf2 was observed. Nrf2 expression increased following As₂O₃ treatment in a dose-dependent manner up to 4?mg As₂O₃?kg^?1 b.w after which no further increase was noticed. NAC pre-treatment significantly reduced the extent of As₂O₃-induced CAs suggesting the protective role of endogenous GSH against arsenic-induced genotoxicity.     

Antimutagenic effect of Maillard browning products obtained from amino acids and sugars.

The antimutagenic effects of Maillard reaction products (MRPs) prepared by heating three sugars (fructose, glucose and xylose) and four amino acids (arginine, glycine, lysine and tryptophan) at 100 degrees C for 10 hr was evaluated in the Salmonella/microsome assay. The highest extent of browning was found in the MRPs of sugars-lysine and xylose-amino acids. The MRPs of xylose-amino acids showed stronger antioxidative activity and reducing power than did the other combinations. No mutagenicity or toxicity in Salmonella typhimurium TA98 was observed with any of the MRPs in the presence of S-9. Most MRPs, especially those of sugars-tryptophan and xylose-amino acids, strongly inhibited the mutagenicity of 2-amino-3-methylimidazo(4,5-f)quinoline (IQ), 3-amino-1,4-dimethyl-5H-pyridol-(4,3-b)indole (Trp-P-1) and 2-amino-6-methyldipyrido(1,2-a:3',2'-d)imidazole (Glu-P-1) in the presence of S-9. However, the MRPs of fructose-glycine and fructose-arginine increased the mutagenicity of Trp-P-1. The antimutagenic effect of the MRPs was well correlated with their antioxidative activity and reducing power. The mutagenicity of benzo[a]pyrene was moderately inhibited by most MRPs, but was increased by the MRP of glucose-arginine. Aflatoxin B1 mutagenicity was increased greatly by all the MRPs except that of xylose-tryptophan. The findings suggested that MRPs might have a bifunctional property of co-mutagenicity and antimutagenicity in certain cases.     

In vitro effects of benzene metabolites on mouse bone marrow stromal cells

Benzene exposure can result in bone marrow myelotoxicity. We examined the effects of benzene metabolites on bone marrow stromal cells of the hemopoietic microenvironment. Male B6C3F1 mouse bone marrow adherent stromal cells were plated at 4 X 10(6) cells per 2 ml of DMEM medium in 35-mm tissue culture dishes. The growing stromal cell cultures were exposed to log 2 doses of five benzene metabolites: hydroquinone, benzoquinone, phenol, catechol, or benzenetriol for 7 days. The dose which caused a 50% decrease in colony formation (TD50) was 2.5 X 10(-6) M for hydroquinone, 17.8 X 10(-6) M for benzoquinone, 60 X 10(-6) M for benzenetriol, 125 X 10(-6) M for catechol, and 190 X 10(-6) M for phenol. We next examined the effect of benzene metabolites on the ability of stromal cells to influence granulocyte/monocyte colony growth (G/M-CFU-C) in a coculture system. Adherent stromal cells were plated and incubated for 14 days and then exposed to a benzene metabolite. After 3 days the medium and metabolite were removed and an agar:RPMI layer containing 10(6) fresh bone marrow cells was placed over the stromal layer. After incubation for 7 days the cultures were scored for G/M colony formation. Hydroquinone and benzoquinone were most toxic, while catechol and benzenetriol inhibited colony growth only at high doses. These results indicate that injured bone marrow stromal cells may be a significant factor in benzene-induced hemotoxicity.     

Mutagenicity and genotoxicity of acid yellow 17 and its biodegradation products

Acid yellow 17 (AY17), a very important commercial azo dye used in the textile industry, was degraded by Pseudomonas putida mt-2 at a concentration of up to 200?mg/L. High-performance liquid chromatography analysis of the biodegradation media revealed the presence of 4-aminobenzensulfonic acid (4-ABS) derived from AY17 azoreduction, which attests the expression of an azoreductase by this bacterium. This amine was identified only in the medium of static incubation, which is consistent with its biotransformation under shaken incubation (i.e., aerobic conditions). The mutagenicity of AY17 and its biodegradation products was evaluated by using Salmonella typhimurium TA102 and TA104. No mutagenicity was observed in the presence or absence of a metabolic activation system (S9). In addition, the ability of tested compounds to induce DNA damage in vitro with the DNA strand scission assay was evaluated. Results showed that only static decolorization culture of AY17 showed a significant ability to induce the pKS plasmid DNA opening. The present study showed that P. putida mt-2, cultivated under aerobic conditions, was able to decolorize, and especially to detoxify, AY17.     

Grape seed extract prevents gentamicin-induced nephrotoxicity and genotoxicity in bone marrow cells of mice

The protection conferred by grape seed extract against gentamicin-induced nephrotoxicity and bone marrow chromosomal aberrations have been evaluated in adult Swiss albino mice. The activity of reduced glutathione peroxidase (GSH peroxidase), the levels of glutathione (GSH) and lipid peroxidation as malondialdehyde (MDA) in the kidneys homogenates, serum urea and creatinine were measured, and in addition the changes in kidney histology and bone marrow chromosomes were investigated. Gentamicin (80 mg/kg b.wt. intraperitoneally for 2 weeks) induced kidney damage as indicated from a pronounced changes in kidney histology, a significant increase in serum urea and creatinine and MDA content in the kidney homogenate. While the activity of the antioxidant enzyme GSH peroxidase and the level of GSH were significantly decreased. Gentamicin induced genotoxicity indicated by increased the number of aberrant cells and different types of structural chromosomal aberrations (fragment, deletion and ring chromosome) and showed no effect on mitotic activity of the cell. Pretreatment with grape seed extract (7 days) and simultaneously (14 days) with gentamicin significantly protected the kidney tissue by ameliorating its antioxidant activity. Moreover, grape seed extract significantly protected bone marrow chromosomes from gentamicin induced genotoxicity by reducing the total number of aberrant cells, and different types of structural chromosomal aberrations. It could be concluded that grape seed extract acts as a potent antioxidant prevented kidney damage and genotoxicity of bone marrow cells.     

Ellagic acid peracetate is superior to ellagic acid in the prevention of genotoxicity due to aflatoxin B1 in bone marrow and lung cells

Earlier observations carried out in our laboratory highlighted the mode of action of acetoxy 4-methylcoumarins and quercetin pentaacetate in preventing the genotoxicity of aflatoxin B1 (AFB1). We have extended the observation to an acetoxy biscoumarin i.e. ellagic acid peracetate (EAPA), which unlike ellagic acid (EA) has demonstrated time-dependent inhibition of liver microsomes catalysed AFB1-epoxidation as measured by AFB1 binding to DNA. EAPA was more potent than EA in preventing bone marrow and lung cells from AFB1-induced genotoxicity. EAPA was acted upon by microsomal acetoxy drug:protein transacetylase (TAase) leading to modulation of the catalytic activity of certain functional proteins (cytochrome P450, NADPH cytochrome c reductase and glutathione S-transferase), possibly by way of protein acetylation.     

Oral subchronic and genotoxicity studies conducted with the amino acid, l-glutamine

l-Glutamine is an abundantly occurring amino acid that serves numerous nutritional and physiological functions. It has current and potential applications as a therapeutic agent, dietary supplement, food ingredient, and in animal nutrition. To assess the safety of supplemental l-glutamine, a bacterial reverse mutation assay, in vitro chromosomal aberration assay, and a 13-week toxicity study were conducted. l-Glutamine showed no mutagenic activity in the bacterial reverse mutation assay, and did not induce chromosomal aberrations in Chinese hamster lung fibroblast cells in the in vitro chromosomal aberration assay. In the 13-week toxicity study, Sprague-Dawley rats (10/sex/group) were fed diets containing 0, 0.5, 2.5, or 5.0% l-glutamine. No deaths occurred, and no significant differences in body weights, body weight gains, ophthalmological findings, urinalysis parameters, or organ weights were observed between l-glutamine-fed rats and their respective controls. No toxicologically relevant effects on hematological or blood biochemical parameters were observed. Macroscopic and microscopic effects occurred at low frequency but were not associated with a dose-response relationship. Based on the results of the study, the no-observed-adverse-effect-level was determined to be 5.0% l-glutamine in the diet, the highest concentration tested (equivalent to 3832 and 4515 mg/kg body weight/day in male and female rats, respectively).     

Cytogenetic toxicity of methotrexate in mouse bone marrow

Methotrexate (MTX), a widely used anticancer drug, was tested for its cytogenetic toxicity in mouse bone marrow after a single intraperitoneal treatment with three different doses i.e. at the rate of 2, 10 and 20 mg/kg b.w. of mice. The end points selected were chromosomal aberrations and mitotic index study at 24-h post-treatment and micronucleus (MN) test at 30-h post-treatment. The induction of statistically significant number of chromosomal aberrations, percentage of aberrant metaphases and highly significant number of MN per thousand polychromatic erythrocytes by all the doses of MTX indicated it as highly clastogenic. MTX was found more clastogenic in male mice than the females and the intermediate dose tested (10 mg/kg) was found more effective than the other doses. In mitotic index study, none of the doses of MTX inhibited cell proliferation during the first post-treated cell cycle. The results were compared with the earlier reports on the clastogenicity and cell proliferation inhibition of MTX only after multiple treatments. The possible mechanism of the cytogenetic effects of MTX has been discussed.     

Chemoprotective effects of hesperidin against genotoxicity induced by cyclophosphamide in mice bone marrow cells

The preventive effect of hesperidin as a flavonoid was investigated in mouse bone marrow cells against genotoxicty induced by cyclophosphamide. Mice were orally (gavages) pretreated with solutions of hesperidin at four different doses (50, 100, 200, and 400 mg/kg b.w.) for five consecutive days. Mice were injected intraperitoneally on the fifth day with cyclophosphamide (50 mg/kg b.w.) and killed after 24 h for the evaluation of micronucleated polychromatic erythrocytes (MnPCEs) and the ratio of PCE/(PCE+NCE) (polychromatic erythrocyte/ polychromatic erythrocyte + normochromatic erythrocyte). Three last doses of hesperidin significantly reduced frequency of MnPCEs induced by cyclophosphamide (p<0.0001). Hesperdin at dose 200 mg/kg b.w. reduced MnPCEs 2.37 time and also completely normalized PCE/ (PCE+NCE) ratio. Histological examination of bone marrow showed that hesperidin affected on proliferation and hyper cellularity of immature myeloid elements in bone marrow that reduced by cyclophsopahmide. It is obvious that hesperidin, may with antioxidative activity, reduced the oxidative stress and genotoxicity induced by cyclophosphamide in mouse bone marrow cells.     

Genotoxicity of Casiopeina III-Ea in mouse bone marrow cells

Casiopeina III-Ea® (Cas III-Ea®) is a chelated copper complex with antineoplastic activity that is capable of reducing tumor size and inducing antiproliferative and apoptotic effects. However, little is known about its in vivo genotoxic effects. Therefore, this study evaluated two cytogenetic and two proliferative parameters 24?h after the administration of Casiopeina III-Ea® to male CD-1 mice. Three doses of Cas III-Ea® were administered by intraperitoneal injections of 1.69, 3.39 and 6.76?mg/kg (corresponding to 1/8, 1/4 and 1/2 of LD₅₀, respectively). A reduction in the mitotic index (MI) and an increased numbers of cells with structural chromosomal aberrations (SCA) were detected. Additionally, a low but significant increase in the frequency of sister chromatid exchange (SCE) was observed at the highest dose. Changes in the DNA replication index (RI) were not observed. These results indicate that Casiopeina III-Ea® shows cytotoxic and clastogenic activity in bone marrow cells from treated mice.     

Study of mutagenicities of phthalic acid and terephthalic acid using in vitro and in vivo genotoxicity tests

Genotoxicities of phthalic acid (PA) and terephthalic acid (TPA) were examined using three mutagenicity tests: Ames, chromosome aberration (CA), and micronucleus (MN). In the Ames test, these two agents did not produce any mutagenic responses in the absence or presence of S9 mix on the Salmonella typhimurium strains TA98, TA100, TA102, TA1535, or TA1537. The CA test also showed that PA and TPA exerted no significant cytogenetic effect on Chinese hamster ovary (CHO) cells. In the mouse MN test, no significant alteration in occurrence of micronucleated polychromatic erythrocytes was observed in ICR male mice ip administered any of these agents at doses of 0, 20, 100, 500, 2500 or 12,500 microM/kg. These results indicate that PA and TPA produced no mutagenic effects using these in vitro and in vivo mutagenic test systems.     

Genotoxic evaluation of letimide with the mouse bone marrow micronucleus test

Letimide, 3[2-(diethylamino)ethyl]-2H-1,3-benzoxazine-2,4(3H)-dione, a new analgesic, is a cyclic derivative of a salicylamide with a higher pharmacological potency than acetylsalicylic acid. In this study we evaluated its clastogenic activity using the micronucleus test in vivo. Our results did not show any clastogenic effect produced by letimide as compared with control mice and animals treated with cyclophosphamide.     

Genotoxicity of ibuprofen in mouse bone marrow cells in vivo

Genotoxicity of ibuprofen was evaluated by employing the mouse in vivo chromosomal aberration (CA) test. Ibuprofen administered orally at doses of 10, 20, 40, and 60?mg/kg body weight to mice resulted in mitotic depression and induction of CAs. A dose-related decrease in mitotic index (MI) and an increase in the frequencies of chromosomal aberrations per cell (CAs/cell) were recorded in bone marrow cells. However, a statistically significant reduction in MI and an increase in CAs/cell were found for both the higher doses. The results obtained indicate that ibuprofen is capable of inducing dose-dependent genotoxicity in bone marrow cells of mice.