Genotoxicity evaluation of Isaria sinclairii (ISE) extract

The mutagenic potential Isaria sinclairii, a traditional Chinese medicine composed of the fruiting bodies of I. sinclairii and its parasitic host larva, was evaluated using short-term genotoxicity tests, namely, the Ames test, chromosome aberration (CA), and micronuclei (MN) tests. In a Salmonella typhimurium assay, I. sinclairii extract (ISE) did not produce any mutagenic response in the absence or presence of 59 mix with TA98, TA100, TA1535, and TA1537. In the chromosome aberration (CA) test, ISE induced no significant effect on Chinese hamster ovary (CHO) cells compared with control. In the MN test, no significant change in the occurrence of micronucleated polychromatic erythrocytes was observed in male ICR mice intraperitoneally administered ISE at doses of 15, 150, or 1500 mg/kg. These results indicate that ISE has no mutagenic potential in these in vitro and in vivo systems.     

Mutagenicity evaluation of phthalic acid esters and metabolites in Salmonella typhimurium cultures

The mutagenic potential of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and di-2-ethylhexyl phthalate (DEPH), as well as metabolites of DEHP--i.e., mono-2-ethylhexyl phthalate (MEHP), 2-ethylhexanol (2-EH), and phthalic acid (PA)--were tested in Salmonella typhimurium cultures using the Ames test procedure. The compounds were tested on strains TA98, TA100, TA1535, TA1537, TA1538, and TA2637 for base-pair substitution or frameshift-type mutations. Spot tests yielded negative responses for all compounds with the strains tested. Each compound was tested for a dose-effect relationship in the TA98, TA100, TA1535, and TA1538 systems. DEP and DBP exhibited a mildly positive response in both TA100 and TA1535 cultures, and DMP showed a similar response in TA1535. Normalization of the data for cytotoxicity of DMP suggests TA100 has a mildly positive effect. The higher doses of these compounds exhibited some cytotoxic effects. The mutagenic effects were apparently abolished by the addition of S9 fraction in TA100 and TA1535 cultures, while no effect, other than cytotoxicity, was observed in the TA98 and TA1538 systems. DEHP, MEHP, 2-EH, and PA exhibited no mutagenicity in any of the strains of Salmonella typhimurium tested, with or without S9 metabolic activation. MEHP and 2-EH, however, exhibited a moderate cytotoxic effect in most cultures.     

Evaluation of the genotoxicity of (-)-hydroxycitric acid (HCA-SX) isolated from Garcinia cambogia

(-)-Hydroxycitric acid (HCA) is widely used as an ingredient for nutritional supplements aimed at reducing food intake, appetite, and body weight. In this study, the genotoxicity of HCA was evaluated using three tests: a bacterial reverse mutation assay (Ames test), an in vitro chromosomal aberration (CA) test, and an in vivo micronucleus (MN) test. HCA was negative by the Ames test in the presence or absence of a microsomal metabolizing system. HCA did not induce mutagenic activity in the Ames test, and no significant mutagenic potency was indicated by CA tests. However, HCA significantly and dose-dependently increased the number of MNPCEs (micronucleated polychromatic erythrocytes/1000 polychromatic erythrocytes) and PCE/(PCE + NCE) ratios according to the MN test. These results suggest that HCA preferentially induce micronuclei.     

Mutagenicity testing of selected analgesics in Ames Salmonella strains

Acetaminophen (APAP), aspirin (ASA), phenacetin (PA) and ibuprofen (IB) were tested for mutagenic activity in the Ames Salmonella plate incorporation assay using strains TA98, TA100, TA1535, TA1537 and TA1538. These analgesics were tested in four separate tests: without metabolic activation, and in the presence of a rat, hamster or mouse liver post-mitochondrial supernatant (S-9, Aroclor 1254-induced). Treatment of all five strains of Salmonella with APAP, ASA or IB under all four metabolic conditions did not induce any appreciable increases in revertant colony counts, as compared to the negative controls. A dose-related increase in revertant colony counts, reaching levels twice the negative control values, were seen with PA at doses greater than or equal to 500 micrograms per plate. This response was only seen in strain TA100 in the presence of hamster S-9. Therefore, these findings constitute a positive result for PA in the Ames test. APAP, ASA and IB did not show any mutagenic potential under these conditions of testing. These findings are discussed along with previously published results concerning the genotoxicity of these analgesics.     

Detection of genotoxicity and mutagenicity of chlorthiophos using micronucleus,chromosome aberration,sister chromatid exchange,and Ames tests

Potential mutagenic and genotoxic effects of Chlorthiophos, an organophosphate pesticide, were evaluated using four standard assays. Five different concentrations of the pesticide were tested by an Ames test using Salmonella typhimurium strains TA97, TA98, TA100, and TA102, with and without S9 metabolic activation. No concentrations of Chlorthiophos showed mutagenic activity on the TA97, TA100, and TA102 strains, with and without S9 fraction, but were all mutagenic to the TA98 strain without S9. Sister chromatid exchange (SCE), chromosome aberration (CA), and micronucleus (MN) tests were used to investigate the genotoxic effects of Chlorthiophos in human peripheral lymphocytes treated with 25, 50, 100, and 200 µg/mL concentrations of Chlorthiophos for 24 and 48 h. The nuclear division index (NDI), replication index (RI), and mitotic index (MI) were also calculated to determine the cytotoxicity of Chlorthiophos. No increase in SCE frequency was seen for any treatment period or concentration, but Chlorthiophos at 200 µg/mL increased the frequency of CAs. Increases in MN formation were only observed at Chlorthiophos concentrations of 200 µg/mL following 24 and 48 h treatments. Chlorthiophos treatment reduced the MI and NDI significantly, but had no effect on the RI. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 937–945, 2015.     

Comparative mutagenicity of apicidin and apicidin derivatives (SD-0203 and SD-2007), histone deacetylase inhibitors

The fungal metabolite apicidin [cyclo(N-O-methyl-L-tryptophanyl-L-isoleucinyl-D-pipecolinyl-L-2-amino-8-oxodecanoyl)] is known to inhibit histone deacetylase (HDAC). In this study, the genotoxicity of apicidin and its derivatives were tested using three tests: a bacterial reverse mutation assay (Ames test), an in vitro chromosome aberration (CA) test, and an in vivo micronucleus (MN) test. Apicidin was negative in the Ames test in the presence and absence of the microsomal metabolizing enzyme system. Apicidin induced a significant increase in the total chromosome aberrations in Chinese hamster ovary (CHO) cells. In the MN test, apicidin induced mutagenic activity at the highest dose (1000 microM/kg). The apicidin derivatives SD-0203 and SD-2007 did not induce mutagenic activity in the Ames test and no significant mutagenic potency was observed in the CA test. However, these compounds significantly and dose-dependently increased the number of micronucleated polychromatic erythrocytes (MNPCEs) as well as the PCE/(PCE + NCE) ratio in the MN test. These results suggest that apicidin and its derivatives preferentially induce CA and MN but are not effective in the Ames test.     

Genotoxicity of quinocetone,cyadox and olaquindox in vitro and in vivo

Quinocetone (QCT) and Cyadox (CYA) are important derivative of heterocyclic N-oxide quinoxaline (QdNO), used actively as antimicrobial feed additives in China. Here, we tested and compared the genotoxic potential of QCT and CYA with olaquindox (OLA) in Ames test, HGPRT gene mutation (HGM) test in V79 cells, unscheduled DNA synthesis (UDS) assay in human peripheral lymphocytes, chromosome aberration (CA) test, and micronucleus (MN) test in mice bone marrow. OLA was found genotoxic in all 5 assays. In Ames test, QCT produced His⁺ mutants at 6.9 μg/plate in Salmonella typhimurium TA 97, at 18.2 μg/plate in TA 100, TA 1535, TA 1537, and at 50 μg/plate in TA 98. CYA produced His⁺ mutants at 18.2 μg/plate in TA 97, TA 1535, and at 50 μg/plate in TA 98, TA 100 and TA 1537. QCT was found positive in HGM and UDS assay at concentrations ⩾10 μg/ml while negative results were reported in CA test and MN test. Collectively, we found that OLA was more genotoxic than QCT and CYA. Genotoxicity of QCT was found at higher concentration levels in Ames test, HGM and UDS assays while CYA showed weak mutagenic potential to bacterial cells in Ames test.     

Tinospora cordifolia, a safety evaluation

Tinospora cordifolia is one of the indispensable medicinal plants used in veterinary folk medicine/Ayurvedic system of medicine for the treatment of diverse diseases and recommended for improving the immune system by means of body resistance. In the current study, we evaluated the genotoxic risk of the aqueous extract of T. cordifolia (TC) in a battery of four different genotoxicity tests viz., Ames, in vitro chromosome aberration (CA), rodent bone marrow micronucleus (MN), and Comet assay. Experimental results confirmed that in Ames test up to 5000 μg/plate of TC did not exhibit any mutagenic effect in Salmonella typhimurium mutant strains (TA97a, TA98, TA100, TA102, and TA1535). In CA assay, TC was not clastogenic to human peripheral blood lymphocytes up to a concentration of 3000 μg/ml. In MN and Comet assays, TC was pre-treated for 7 days at three dose levels (150, 200 and 250 mg/kg body weight) orally to male Balb/c mice. The results showed that TC treatment did not display clastogenicity and DNA damaging effect in bone marrow erythrocytes and peripheral blood lymphocytes respectively.     

Genotoxic evaluation of the biocomponents of the cricket, Gryllus bimaculatus, using three mutagenicity tests

The mutagenic potential of the extracted components of Gryllus bimaculatus, a species of cricket, was evaluated using short-term genotoxicity tests including the Ames, chromosome aberration, and micronuclei tests. In a Salmonella typhimurium assay, G. bimaculatus extract did not produce any mutagenic response in the absence or presence of S9 mix with TA98, TA100, TA1535, and TA1537. Chromosome aberration testing showed that G. bimaculatus had no significant effect on Chinese hamster ovary (CHO) cells. In the mouse micronucleus test, no significant alteration in occurrence of micronucleated polychromatic erythrocytes was observed in ICR male mice intraperitoneally administered with G. bimaculatus extract at doses of 15, 150, or 1500 mg/kg. These results indicate that G. bimaculatus extract exerts no mutagenic effect in these in vitro and in vivo systems.     

Mutagenicity and DNA-damaging activity caused by decomposed products of potassium sorbate reacting with ascorbic acid in the presence of Fe salt.

Although potassium sorbate (PS), ascorbic acid and ferric or ferrous salts (Fe-salts) are used widely in combination as food additives, the strong reactivity of PS and oxidative potency of ascorbic acid in the presence of Fe-salts might form toxic compounds in food during its deposit and distribution. In the present paper, the reaction mixture of PS, ascorbic acid and Fe-salts was evaluated for mutagenicity and DNA-damaging activity by means of the Ames test and rec-assay. Effective lethality was observed in the rec-assay. No mutagenicity was induced in either Salmonella typhimurium strains TA98 (with or without S-9 mix) or TA100 (with S-9 mix). In contrast, a dose-dependent mutagenic effect was obtained when applied to strain TA100 without S-9 mix. The mutagenic activity became stronger increasing with the reaction period. Furthermore, the reaction products obtained in a nitrogen atmosphere did not show any mutagenic and DNA-damaging activity. PS, ascorbic acid and Fe-salts were inactive when they were used separately. Omission of one component from the mixture of PS, ascorbic acid and Fe-salt turned the reaction system inactive. These results demonstrate that ascorbic acid and Fe-salt oxidized PS and the oxidative products caused mutagenicity and DNA-damaging activity.     

酸枣仁油的致突变作用的研究

目的对酸枣仁油进行毒理学试验,探讨酸枣仁油是否有致突变作用。方法①小鼠急性毒性试验:一次最大限量法。②Ames试验:选用经鉴定符合要求的鼠伤寒沙门氏组氨酸缺陷型TA97、TA98、TA100、TA102试验菌株,采用平板掺入法。③小鼠骨髓嗜多染红细胞微核试验。结果酸枣仁油对雌雄小鼠经口LD50均>10g/kg,为实际无毒级物质;骨髓嗜多染红细胞微核实验和Ames试验未发现破酸枣仁油对小鼠有致突变作用。结论从毒理学角度可以认为酸枣仁油作为保健食品用于人体是安全的。     

Genotoxic evaluation of Halfenprox using the human peripheral lymphocyte micronucleus assay and the Ames test

The genotoxicity and mutagenicity of Halfenprox, a synthetic pyrethroid insecticide and acaricide, was assessed using two standard genotoxicity assays of the Salmonella typhimurium mutagenicity assay (Ames test) and in vitro micronucleus (MN) assay in human peripheral lymphocytes. In the Ames test, Salmonella strains TA98 and TA100 were treated with or without S9 fraction. The doses of Halfenprox were 6.25, 12.5, 25, 50, and 100?μg/plate and test materials were dissolved in DMSO. The concentrations of Halfenprox did not show mutagenic activity on both strains with and without S9 fraction. The MN assay was used to investigate the genotoxic effects of Halfenprox in human peripheral lymphocytes treated with 250, 500, 750, and 1000?μg/ml concentrations of Halfenprox for 24 and 48?h, and at 1000?μg/ml the concentration was significantly increased and the MN formation was compared with the negative control for both treatment periods. In addition, a significant decrease of the nuclear devision index (NDI) values at the higher concentrations of Halfenprox and at both treatment periods was observed.     

Studies of the toxicological potential of tripeptides (L-valyl-L-prolyl-L-proline and L-isoleucyl-L-prolyl-L-proline): IX. Evaluation of the mutagenic potential of synthesized L-valyl-L-prolyl-L-proline in the Salmonella-Escherichia coli/microsome, incorporation assay

The objective of this study was to assess the mutagenic potential of a synthesized tripeptide, L-valyl-L-prolyl-L-proline (VPP), to induce mutational changes in Salmonella typhimurium LT2 strains TA1535, TA1537, TA98, and TA100, and Escherichia coli strain WP2uvrA in the classical Ames test protocol. Bacteria were exposed to plate concentrations of VPP of 0, 156.2, 312.5, 625, 1250, 2500, and 5,000 microg/plate in distilled water, in the presence and absence of Aroclor 1254-induced rat liver homogenate preparation (S9). Positive-control agents included sodium azide (TA100 and TA1535); 2-aminoanthracene (TA98, TA100, TA1535, TA1537, and WP2uvrA); 9-aminoacridine (TA1537); 2-nitrofluorene (TA98); and N-ethyl-N'-nitro-N-nitrosoguanidine (WP2uvrA) in DMSO. Incubations were conducted at 37 degrees C for about 48 h then revertant colonies were counted. All positive-control agents were consistently and unequivocally positive, but there was no evidence that VPP induced increases in the incidences of revertant colonies in any bacterial strain with and without metabolic activation. These findings were replicated in a second, confirmatory test performed with and without S9. The results of the experiments revealed no treatment-associated changes in the incidence of revertant colonies in any bacterial strain tested. These results support a conclusion that, under the experimental conditions described, there is no evidence that VPP possesses mutagenic potential.     

The mutagenic, DNA-damaging and antioxidative properties of bark and leaf extracts from Coutarea hexandra (Jacq.) K. Schum

Coutarea hexandra is a species commonly known in Brazil as quina, and its bark is used in folk medicine. In this study, we assess the mutagenic and DNA-damaging effects of ethanol extracts from C. hexandra stem bark (SCH) and leaves (LCH) by employing the Ames test on the TA98 and TA100 strains of Salmonella typhimurium in addition to a plasmid treatment test. Furthermore, we performed a phytochemical analysis by TLC and HPLC, a quantification of the phenolic constituents and an assessment of the antioxidative activity. SCH and LCH showed mutagenic action in the Ames test for TA98 strains after metabolic activation. LCH also showed mutagenicity for the TA100 strain after metabolic activation. The findings from the plasmid treatment test did not indicate any DNA-damaging activity for either of the extracts with the tested dosages. SCH showed greater flavonoid content and greater antioxidative potential in relation to LCH. This study suggests that caution is advisable in the use of this plant. However, in vivo studies should be conducted to confirm these data.     

Mutagenicity and cytotoxicity of N-methyl-2-pyrrolidinone and 4-(methylamino)butanoic acid in the Salmonella/microsome assay

The industrial solvent N-methyl-2-pyrrolidinone (NMP) and its hydrolysis product, 4-(methylamino)butanoic acid (N-MeGABA), were examined for mutagenicity and cytotoxicity in the Ames Salmonella/microsome assay. In order to detect a broad range of possible mutagenic endpoints, the following strains were used in the assay: base-pair substitution strains TA100, TA102 and TA104; frameshift strains TA97 and TA98; and repair proficient strains TA2638, UTH8413 and UTH8414. In the standard plate incorporation assay, six log-linear doses of each compound were tested; doses ranged from 0.01 to 1000 mumol/plate for NMP, and 0.01 to 316 mumol/plate for N-MeGABA. Neither compound was detectably mutagenic when tested in the presence and absence of metabolic activation by Aroclor-induced rat liver S9. NMP did show significant responses with strains TA102 and TA104 that were less than two-fold over background, but no clear dose-response relationships were evident. A preincubation modification of the assay was also performed, using strains TA98 and TA104. Mutagenic activity was not observed for NMP, while N-MeGABA showed significant responses with TA104 but dose-related mutagenicity was not established. Preincubation testing revealed both NMP and N-MeGABA to be cytotoxic to the test population of Salmonella at the highest treatment doses.     

The genotoxic and antigenotoxic effects of tannic acid in human lymphocytes

The genotoxicity of tannic acid (TA, tannin) were investigated using chromosome aberration (CA), sister chromatid exchange (SCE), and micronucleus (MN) test systems in human peripheral lymphocytes. Also, the antigenotoxicity of TA against known mutagen EMS was also examined. The lymphocytes were treated with 1.74?×?10(-5), 3.49?×?10(-5), and 6.98?×?10(-5) μM of TA for 24- and 48-hour treatment periods. For the antigenotoxicity of TA, the lymphocytes were treated with three different concentrations of TA and 2.71 μM of EMS. TA synergically induced the CA alone and with the mixture of EMS. However, TA did not induce the SCE alone, whereas TA and EMS as a mixture also synergically induced SCE. TA alone showed no clear effect on micronucleus formation, and it did not induce the MN when used with EMS as a mixture. In addition, TA showed a synergistic cytotoxic effect by decreasing the mitotic and nuclear division indices. The replication index was decreased at all concentrations for 48 hours of treatment time by TA and EMS as a mixture.     

Mutagenicity and anti-mutagenicity of Acanthopanax divaricatus var. albeofructus

The beneficial effects of Acanthopanax divaricatus var. albeofructus (ADA) extracts have been assessed by mutagenic and anti-mutagenic activities by Ames test. Mutation of Salmonella typhimurium strains TA 98, TA 100, TA1535, TA1537, and Escherichia coli WP2 uvr A was assayed in duplicates by the procedure of Maron and Ames in the presence or absence of S9 mix. As a result, ADA extracts were not mutagenic for S. typhimurium strains TA 98, TA 100, TA1535, TA1537, and E. coli by the Ames assay. Anti-mutagenic activity was assayed by the Ames mutagenicity assay using histidine mutant of S. typhimurium strains TA 98 and TA 100, using the plate-incorporation method. 2-Aminoanthrancene (2-AA), 2-(2-furyl)-3-(5-nitro-2-furyl) acrylamide (AF-2), and sodium azide (NaN(3)) were used as the mutagens. ADA extracts showed a strong anti-mutagenic activity against 2-AA-induced mutagenesis which requires liver-metabolizing enzymes, and the same extract exhibited inhibitory effects on AF-2 and NaN(3)-induced mutagenesis in the absence of liver-metabolizing enzymes. The data indicate that ADA extracts contain anti-mutagenic activities against typical mutagens. The anti-mutagenic property of ADA provides additional health supplemental value to the other claimed therapeutic properties of the plant.     

Fate and toxicity assessment of linear alkylbenzene sulfonates in drinking water using the ames test

The genotoxic activity of the methanolic water extracts of prechlorinated water from Barcelona (NE Spain) using the Ames test was studied. High performance liquid chromatography (HPLC) and mass spectrometry in the mass spectroscopy/fast atom bombardment mode (MS/FAB) was employed to tentatively identify organic compounds responsible of genotoxic activity. Methanolic extracts of prechlorinated water were highly mutagenic in the Ames test, mainly with the TA98 strain for concentration lesser than 1 L. On the other hand, the TA100 strain showed higher mutagenicity for tap water extracts and concentrations higher than 1 L. Also, a strong toxic effect was observed when methanolic extracts were analyzed by the Ames test. Toxicity showed a reduction of the genotoxic ratio by a characteristic negative slope for the concentration vs genotoxicity curve. Toxicity was usually observed using the TAlOO strain and at a higher concentration than mutagenicity does. Both mutagenicity and toxicity in the Ames test showed a characteristic pattern depending on their origin (tap or prechlorinated water). It was possible to separate mutagenic from toxic fractions by HPLC. These subfractions were analyzed by MS/FAB in order to identify the organic compounds responsible for these effects, but unsuccessful results were obtained for mutagenic subfractions. Alkylbenzenesulfonates (LA3) were the sole compounds identified in toxic subfractions. The correlation between toxicity of samples (TA100 strain) and the presence of LAS was proved by comparison of toxicity from a standard LAS and those observed from real samples. An EC ₅₀ of 9.8 mg/L for LAS has been established by the Ames test using the TAlOO strain. © 1993 John Wiley & Sans, Inc.     

Limitations of urinary mutagen assays for monitoring occupational exposure to antineoplastic drugs

The sensitivity of the Salmonella reversion test of Ames as a screen for accidental absorption of 17 antineoplastic agents by drug handlers was evaluated. Dilutions of each drug were added to agar inoculated with each of two Salmonella typhimurium strains (TA98 and TA100); control plates contained no test drug. Colonies were counted after incubation at 36 degrees C for 48 hours. The drugs were tested in the presence of a liver preparation to provide metabolic activation of mutagenicity. Urine samples collected from patients after doses of three mutagenic drugs were extracted and tested with the Ames test. For 11 of the 17 drug solutions, no mutagenic activity was seen, but many of these 11 were toxic to the organisms. The most highly mutagenic drugs were doxorubicin and cisplatin, with mechlorethamine, carmustine, dacarbazine, and cyclophosphamide exhibiting less mutagenic activity. Urine from patients treated with doxorubicin or cyclophosphamide showed mutagenicity, but the results suggested that the quantity of these drugs that would have to be absorbed to produce a definite reaction in urine is unlikely to be achieved by drug handlers who use standard precautions. Because of its lack of sensitivity and the potential effects of environmental and dietary factors on the results, this bacterial mutagenicity test should not be used routinely for detection of accidental absorption of antineoplastic drugs.     

Methemoglobinogenic potential of primaquine and its mutagenicity in the Ames test

Single doses of primaquine did not produce methemoglobinemia in beagle bitches. Repeated daily administration for 12 days produced a gradually rising level of methemoglobin over that time period, unaccompanied by depletion of erythrocytic reduced glutathione. Primaquine was mutagenic in the Ames test in Salmonella typhimurium strain TA 1537, with or without S9, using a liquid preincubation assay. Primaquine was non-mutagenic in this assay to strains TA 1535, TA 1538, TA 98 and TA 100, regardless of the presence or absence of S9. In the standard overpour Ames test, the drug was non-mutagenic in all 5 Salmonella strains, both with and without S9 metabolic activation.