Protective properties of five newly synthesized cyclic compounds against sodium azide and N-methyl-N'-nitro-N-nitrosoguanidine genotoxicity

The current study aims to determine the antimutagenic potential of five newly synthesized cyclic compounds against the genotoxic agents sodium azide (NaN?) and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The mutant bacterial tester strains were NaN?-sensitive Salmonella typhimurium TA1535 and MNNG-sensitive Escherichia coli WP2uvrA. According to the results, all the test compounds showed significant antimutagenic activity. The inhibition rates ranged from 26.05% (Compound 4-1 μg/plate) to 68.54% (Compound 5-0.01 μg/plate) for NaN? and from 32.44% (Compound 3-1 μg/plate) to 60.77% (Compound 5-1 μg/plate) for MNNG genotoxicity. Moreover, the mutagenic potential of the test compounds was investigated using the same strains. The results showed that all the test compounds do not have mutagenic potential on the bacterial strains at the tested concentrations. Thus, the findings of the present study give valuable information about chemical prevention from NaN? and MNNG genotoxicity.     

Nonmutagenicity of curcumin and its antimutagenic action versus chili and capsaicin

Turmeric, which is one of the commonly used spices in Indian cooking, was tested for mutagenicity using the Ames test. The alcoholic extract of fresh or dried turmeric, its principal components, and pyrolyzed turmeric powder and curcumin were tested for mutagenicity in Salmonella typhimurium strains with and without metabolic activation. None of these were mutagenic in all the tester strains. Chilies (which are used with turmeric powder) and their principal alkaloid capsaicin were mutagenic in the TA 98 with S9 mixture. We tested curcumin, which is the principal component of turmeric, for its antimutagenic effect. It showed dose-dependent decreases in mutagenicity of chili extract and capsaicin. Also, we compared the antimutagenicity of curcumin with other known antioxidants, including BHA, vitamins E and C, and vegetable oils. These all showed dose-dependent decreases in mutagenicity of chili extract and capsaicin. These studies show that although there are few mutagenic principles in Indian food, there is still quite a large number of antimutagenic principles in the Indian diet that will modulate the activity of environmental mutagens.     

Antioxidant and antimutagenic activities of Cinnamomum zeylanicum fruit extracts

Recently, a number of studies on the health benefits associated with natural compounds have been demonstrated. Phenolics in fruits, vegetables, herbs and spices possess potent antioxidant, anti-inflammatory, antimutagenic and anticarcinogenic activities. In the present study, the dried fruits of cinnamon were extracted with ethyl acetate, acetone, methanol and water using a Soxhlet extractor. The total phenolics content of the extracts as determined by Folin–Ciocalteu method were found to be the highest in water extract (44.5%) and the lowest in ethyl acetate (14.4%). The antioxidant activity (AA) of the extracts was evaluated through in vitro model systems such as β-carotene-linoleate, and 1,1-diphenyl-2-picryl hydrazyl (DPPH); the antimutagenicity of these extracts was also assayed against the mutagenicity of sodium azide by Ames test using tester strain of Salmonella typhimurium (TA100) at different concentrations. In both the model systems, the AA of the extracts was found in the order of water>methanol>acetone>ethyl acetate. All the extracts decreased sodium azide mutagenicity in S. typhimurium strain (TA100). At 5000 μg/plate all the extracts showed strong antimutagenicity. The antimutagenicity of water extract was followed by acetone, methanol and ethyl acetate. The results of the present study indicate that under-utilized and unconventional part of cinnamon is a good source of antioxidant and antimutagenic phenolics.     

Nonmutagenicity of curcumin and its antimutagenic action versus chili and capsaicin

Turmeric, which is one of the commonly used spices in Indian cooking, was tested for mutagenicity using the Ames test. The alcoholic extract of fresh or dried turmeric, its principal components, and pyrolyzed turmeric powder and curcumin were tested for mutagenicity in Salmonella typhimurium strains with and without metabolic activation. None of these were mutagenic in all the tester strains. Chilies (which are used with turmeric powder) and their principal alkaloid capsaicin were mutagenic in the TA 98 with S9 mixture. We tested curcumin, which is the principal component of turmeric, for its antimutagenic effect. It showed dose‐dependent decreases in mutagenicity of chili extract and capsaicin. Also, we compared the antimutagenicity of curcumin with other known antioxidants, including BHA, vitamins E and C, and vegetable oils. These all showed dose‐dependent decreases in mutagenicity of chili extract and capsaicin. These studies show that although there are few mutagenic principles in Indian food, there is still quite a large number of antimutagenic principles in the Indian diet that will modulate the activity of environmental mutagens.     

Mutagenic activity of airborne particulate matter (PM10) in a sugarcane farming area (Araraquara city, southeast Brazil)

Brazil contains 25% of the total land planted with sugarcane in the world and is thus one of the major producers. The annual burning of sugarcane fields prior to harvesting emits huge amounts of pyrogenic particles. Biomass burning is an important primary and secondary source of aerosol particles. The presence of carbonaceous particles in the inhalable size range makes it important to study this fraction in view of the possible effects on human health and the climate. In this study, the mutagenic activity associated with inhalable airborne particulate matter (PM₁₀) collected on air filters in a sugarcane-growing area near the city of Araraquara (SE Brazil) was determined. The extracts were dissolved in dimethylsulfoxide and tested for mutagenicity by the Ames plate incorporation test with Salmonella typhimurium YG1024 in the presence and absence of the S9 mixture. To assess the association between mutagenicity and PM₁₀, samples were collected in sugarcane harvesting and non-harvesting periods of the year. Significant mutagenicity was detected in organic solvent extracts of all samples, with differences between the two periods. The highest values of mutagenic potency (13.45 and 5.72 revertants/m³ of air in the absence and presence of the S9 mixture, respectively) were observed during the harvest. In this period, a Teflon™-coated glass-fiber air filter trapped 67.0 μg of particulate matter per m³ of air. In the non-harvest period, on the same type of filter, only 20.9 μg of particulate matter was found per m³. The mutagenic potencies at this time were 1.30 and 1.04 revertants/m³ of air, in the absence and presence of the S9 mixture, respectively. Period, concentration of PM₁₀ and mutagenicity were associated with each other. For routine monitoring of mutagenicity in the atmosphere, the use of YG1024 tester strain without metabolic activation (S9) is recommended.     

Mutagenic activity of surface waters adjacent to a nuclear fuel processing facility

Surface waters adjacent to a nuclear fuel processing facility were extracted, using XAD-resin adsorption followed by solvent elution, and the extracts were assayed for mutagenic potential by the AmesSalmonella-mammalian microsome test. Dose-related mutagenic responses with TA102 (+ S9) were produced with the extracts of water samples obtained from a creek receiving waste-water from the processing facility (specific mutagenic activities of 7,250 to 8,250 net revertants per L equivalent of water). The creek water extracts were not mutagenic with TA102 in the absence of S9, or with any other tester strain (i.e., TA97, TA98, TA100, and TA1535) in the presence or absence of S9. Surface water samples downstream and upstream of this creek were not mutagenic; apparently indicating the lack of persistence of the observed mutagenicity. The major constituent in the mutagenic creek water extracts was identified as tributylphosphate (TBP) by gas chromatography-mass spectrometry. However, TBP was not mutagenic with TA102 (+ S9) at doses ranging from 196 g/plate to 9.8 ng/plate. Because tester strain TA102 detects oxidative mutagenesis due to x-rays and ultraviolet radiation, it is possible that the observed mutagenicity of creek water extracts was due to radionuclides complexed to TBP.     

Modulatory effect of Byrsonima basiloba extracts on the mutagenicity of certain direct and indirect-acting mutagens in Salmonella typhimurium assays

Byrsonima basiloba A. Juss. species is a native arboreal type from the Brazilian "cerrado" (tropical American savanna), and the local population uses it to treat diseases, such as diarrhea and gastric ulcer. It belongs to the Malpighiaceae family, and it is commonly known as "murici." Considering the popular use of B. basiloba derivatives and the lack of pharmacological potential studies regarding this vegetal species, the mutagenic and antimutagenic effect of methanol (MeOH) and chloroform extracts were evaluated by the Ames test, using strains TA97a, TA98, TA100, and TA102 of Salmonella typhimurium. No mutagenic activity was observed in any of the extracts. To evaluate the antimutagenic potential, direct and indirect mutagenic agents were used: 4 nitro-o-phenylenediamine, sodium azide, mitomycin C, aflatoxin B(1), benzo[a]pyrene, and hydrogen peroxide. Both the extracts evaluated showed antimutagenic activity, but the highest value of inhibition level (89%) was obtained with the MeOH extract and strain TA100 in the presence of aflatoxin B(1). Phytochemical analysis of the extracts revealed the presence of n-alkanes, lupeol, ursolic and oleanolic acid, (+)-catechin, quercetin-3-O-alpha-L-arabinopyranoside, gallic acid, methyl gallate, amentoflavone, quercetin, quercetin-3-O-(2"-O-galloyl)-beta-D-galactopyranoside, and quercetin-3-O-(2"-O-galloyl)-alpha-L-arabinopyranoside.     

A mutagenic screening of various herbs,spices, and food additives

Chloroform and methanol extracts of various herbs and spices as well as food additives were screened for mutagenicity using the Salmonella/microsome assay of Ames and the Salmonella typhimurium strains TA100 and TA98. The results of this general screening, however, did not provide sufficient information to fully assess the mutagenic potential of certain herbs and spices since the assay of their respective extracts was accompanied by a growth inhibition of the bacterial tester strain. These findings were attributed to the effects of toxic compounds that were presumably contained within the complex mixtures that comprise both herbs and spices. An apparent reduction in the effects of toxicity was observed when separation methods were used as a means to obtain fewer compounds in each of the samples assayed for mutagenicity.

Following a separation by column chromatography of the chloroform and methanol extracts of cumin, a dose related response of weak mutagenicity was demonstrated toward TA100 but not TA98 with one of the 17 fractions collected. Positive responses to mutagenicity in the absence of toxicity were obtained when chloroform and methanol extracts and food additives were fed to rats, and the metabolites present in ether extracts of 24‐hour urine samples were subsequently assayed for mutagenicity. Weak mutagenic activities toward TA100 but not TA98 were observed with each of the urine extracts of rats fed the following samples: β terpineol, camphene, two separate combinations of the methanol fractions of cumin, a chloroform fraction of cumin, the combined chloroform and methanol fraction of star anise and either the chloroform or methanol fractions of tarragon. With the exception of the chloroform fraction of cumin, the extracts and food additives administered to rats appeared to require an in vivo metabolic activation to detect their mutagenic forms. Mutagenicity was only detected when the ether extracts of urinary metabolites were assayed, even though tests preceding the rat feedings were performed in the presence of the rat liver microsome fraction S9.     

Effect of butylated hydroxytoluene and butylated hydroxyanisole on the mutagenicity of 3,2´‐dimethyl‐4‐aminobiphenyl

This study was undertaken to investigate the possible antimutagenic effects of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) on 3,2´‐dimethyl‐4‐aminobiphenyl (DMAB)‐induced mutagenicity, using the Ames Salmonella/mammalian microsome system. The addition of 100–250 μg of BHT or 25–500 μg of BHA/plate was found to inhibit DMAB‐induced mutagenicity in Salmonella strains TA 98 and TA 100. In TA 100, the mutagenicity was further inhibited with the addition of S9 prepared from the livers of rats fed a 0.6% BHT diet as compared to S9 from the animals fed a diet containing no BHT.     

Mutagenicity and antimutagenicity testing of six chemicals associated with the pungent properties of specific spices as revealed by the Ames Salmonella/microsomal assay

Three compounds, capsaicin, thymol and borneol, were initially screened for mutagenic activity using Salmonella typhimurium strains TA97, TA98 and TA100, with and without S9 metabolic activation, and 20 min standard preincubation time. Three other compounds, allyl isothiocyanate, eugenol and cinnamaldehyde, were screened for mutagenic activity as above, but with a prolonged, nonstandard preincubation time of up to 120 minutes. All six test compounds used in the assays are associated with the pungent properties of some specific spices in which the test compounds can be found to exist naturally. The first objective of this study was to observe if mutagenic activity can be correlated to the pungent properties of these six test compounds. However, due to toxicity and the observation that only capsaicin was mutagenic, using strain TA100 in the presence of S9 metabolic activation, it was not possible to deduce any relationship between mutagenicity and the test chemials' pungent properties. Naturally occurring capsaicin, found in the spice Capsicum annum, was detected and quantified using thin layer and gas chromatographic techniques.The final objective was to detect the presence of antimutagenic factor(s) in C. annum that would suppress the mutagenicity of capsaicin. When the mutagenic capsaicin and 2-aminoanthracene were assayed in the presence of C. annum acetone extract, using strain TA100 with S9 metabolic activation, the mutagenic response of both the mutagens were reduced by approximately 50%. Assaying capsaicin and 2-aminoanthracene in the presence of chlorophyll, the mutagenic response of the two mutagens was reduced by less than 40%. From this observation it was inferred that chlorophyll can successfully suppress the mutagenicity activities of capsaicin and 2-aminoanthracene, together with other antimutagenic factors that were present in the acetone extract of C. annum.     

Mutagenicity of used crankcase oils from diesel and spark ignition automobiles

The Salmonella mutagenicity assay was used to compare the mutagenic activity of used crankcase oil (UCO) from diesel and spark-ignition (gasoline) engine passenger cars. UCO samples were obtained during periodic oil changes from 9 spark-ignition and 10 diesel-powered vehicles. Five samples of unused motor oil were also tested. Direct tests of UCO did not detect mutagenic activity in Salmonella typhimurium strain TA-98. Therefore, an extraction procedure was used to concentrate the mutagens and remove interfering chemicals. Extracts were tested both with and without Aroclor-1254-induced rat liver homogenate fraction (S-9). Dose-dependent mutagenicity with and without S-9 was observed in both diesel and spark-ignition engine UCO extracts. Mutagenic activity was also found in unused oil extracts, but it was lower than that in UCO extracts and generally required addition of S-9. The mutagenic potency of diesel UCO extracts was similar to that of gasoline UCO extracts, both with and without addition of S-9. This indicated that potential health risks associated with disposal, handling, and recycling of diesel UCO may not be significantly different from those of UCO from gasoline engines.     

Toxicity reduction evaluation at a municipal wastewater treatment plant using mutagenicity as an endpoint

Previous work revealed substantial levels of mutagenicity in effluents from certain municipal wastewater treatment plants. One of these treatment plants was selected for further study to track the effluent mutagenicity to its sources, to chemically characterize the mutagenicity, and to assess the treatability of the mutagens. Mutagenicity testing using the Salmonella/microsome assay was performed on methylene chloride extracts of influent and effluent samples from the municipal wastewater treatment plant, as well as on four selected industrial effluents entering the plant. The mutagenicity of the influent samples was detected only in the presence of a microsomal metabolic activation system and was highest in Salmonella strain TA98. About two-thirds of the mutagenicity passed through the treatment plant, suggesting that the mutagenic compounds were refractory to conventional biological treatment. No significant mutagenic activity was detected in three of the industrial waste streams, all paper products plant discharges. However, a high level of mutagenicity (1.2 million TA98 revertants/liter) was detected in the effluent from a coke oven plant. This source could account for all of the mutagenicity entering the wastewater treatment plant. After fractionation of the coke oven effluent by sequential extraction at neutral, acidic and basic pH with methylene chloride, 93% of the TA98 (+S9) mutagenicity was found in the neutral fraction. A C₁₈ column fractionation scheme using a methanol/water elution gradient revealed that 92% of the mutagenicity eluted with the 75% and the 80% methanol in water fractions. The C₁₈ fractionation also provided good separation of mutagenicity from toxicity to fathead minnows. This study has demonstrated the potential of toxicity reduction evaluation (TRE) methodology for tracing effluent toxicity to its source, using genotoxicity as an endpoint.Disclaimer. This article has been reviewed by the U.S. Environmental Protection Agency and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

Genotoxic properties of municipal wastewaters in Ohio

Wastewaters from six municipal wastewater treatment plants in Ohio were tested at different stages of treatment for mutagenicity in the Ames/Salmonella assay. The chlorinated secondary effluents were also evaluated for induction of sister chromatid exchanges in Chinese hamster ovary cells. Direct-acting microbial mutagenicity was observed for extracts of the effluents from all six plants for both an initial and a repeat sampling series. In some cases, the mutagenicity was greatly enhanced by S9 metabolic activation (MA). In general, the specific mutagenicity of the extracts increased following activated sludge treatment. Chlorination resulted in substantial increases in mutagenic activity for some of the Wastewaters but had no effect on others. SCE inducing activity was detected in five out of six extracts for the first sample series, and for two out of five extracts for the second sample series. There was no obvious correlation in the ability of the extracts from the chlorinated secondary effluents to induce SCE in CHO cells and to induce mutations in Salmonella.     

冬季重污染天气大气PM_(2.5)致突变性的初步研究

目的利用鼠伤寒沙门菌回复突变试验(Ames试验)测定冬季重污染天气下PM_(2.5)的致突变性。方法利用大流量采样器收集冬季优良天气及重污染天气PM_(2.5),PM_(2.5)全颗粒物剂量为100、250、500和1 000μg/皿,选用TA98菌株,采用平板掺入法进行Ames试验。结果优良天气下收集的PM_(2.5)在500、1 000μg/皿-S9剂量组及1 000μg/皿+S9剂量组致突变率(MR)2且有剂量-效应关系;严重污染天气下收集的PM_(2.5)在250、500和1 000μg/皿±S9剂量组MR2且有剂量-效应关系。结论 PM_(2.5)全颗粒物对TA98具有一定的致突变效应。     

Validity of mutagenic activity as an indicator of river water pollution

Objectives To investigate if mutagenicity could be expressed by known water pollution indicators, we determined the mutagenic activity of blue rayon extracts from sampled river water with the Ames test utilizing new strains of bacteria, and compared the results with those of known indicators of water pollution. Methods Water samples were collected by the blue rayon adsorption method at sixteen sites in six rivers in the North Kyushu district. The Assay of mutagenicity was carried out using the Ames test. The test strains wereSalmonella typhimurium TA100, YG1024, YG1041 and YG1042. B(a)P, Trp-P-1 and Trp-P-2 were quantified by HPLC. Determinations of SS, BOD, COD, T-N, T-P, DOC, and A₂₆₀/DOC were performed. Results The extracts from five sampling sites showed higher mutagenicity toward strain YG1024 with or without S9mix, and the extracts from two of these five sites showed higher mutagenicity toward strain YG1041 with and without S9mix. However, the water pollution indicators did not show specific trends that were consistent with the mutagenic activity. Conclusions Since the mutagenic activity of river water could not be predicted using known water pollution indicators, we recommend that biological examinations such as mutagenicity tests be added to the indicators that are currently in use.     

Genotoxic and Mutagenic Potential of Agricultural Soil Irrigated with Tannery Effluents at Jajmau (Kanpur), India

It is a common practice in India to irrigate agricultural fields with wastewater originating from industries and domestic sources. At Jajmau (Kanpur), India, tannery effluent is used for irrigation purposes. This practice has been polluting the soil directly and groundwater and food crops indirectly. This study is aimed at evaluating the mutagenic impact of soil irrigated with tannery effluent. Soil extracts were prepared using four organic solvents (dichloromethane, methanol, acetonitrile, and acetone) and tested with Ames Salmonella/microsome test and DNA repair-defective E. coli k-12 mutants. Gas Chromatography-mass spectrometric analysis of soil samples revealed the presence of a large number of organic compounds including bis(2-ethylhexyl)phthalate, benzene, 1,3-hexadien-5-yne, 2,4-bis(1,1-dimethyl)phenol, Docosane, 10-methylnonadecane, and many higher alkanes. The soil extracts exhibited significant mutagenicity with Ames tester strains. TA98 was found to be the most sensitive strains to all the soil extracts, producing maximum response in terms of mutagenic index of 14.2 (–S9) and 13.6 (+S9) in the presence of dichloromethane extract. Dichloromethane-extracted soil exhibited a maximum mutagenic potential of 17.3 (–S9) and 20.0 (+S9) revertants/mg soil equivalent in TA100. Methanol, acetonitrile, and acetone extracts were also found to be mutagenic. A significant decline in the survival of DNA repair-defective E. coli K-12 mutants was observed compared to their isogenic wild-type counterparts when treated with different soil extracts. PolA mutant was found to be the most sensitive strain toward all four soil extracts.     

武汉易家墩地区污水养鱼场鱼体底泥及水中有机致突变物的测定

本文研究武汉易家墩地区利用工业及生活污水养殖,非挥发性有机致突变物在塘水,鱼体组织及底泥中的存在状况及相互关系。结果显示鱼塘水受到污水的严重污染,水样(经换算后体积)100m1/皿即对TA98、TA100菌株具有致突变性,鱼样(经换算后重量)0.1g/皿时就表现为阳性,提示水中有机致突变物可通过食物链危害人体健康。鱼塘底泥在本实验中未显阳性结果。     

Role of nitrosation in the mutagenic activity of coal dust: a postulation for gastric carcinogenesis in coal miners

The mutagenicity of coal dust solvent extracts with and without nitrosation was studied using the Salmonella/microsome assay system. Coal dust solvent extracts were either non-mutagenic or very weakly mutagenic with S9 activation. High mutagenic activities, however, were found when extracts of bituminous, subbituminous, and lignite coal dusts were reacted with nitrite under an acidic condition. Formation of mutagens from coal dust extracts by nitrosation was highest at pH 3.2 and decreased with increasing pH in the reaction mixture. Mutagenic activity appeared to be independent of metabolic activation. The mutagens formed from nitrosation of coal dust extracts induced frameshift mutations. The results reported here may have possible implications for the explanation of an elevated incidence of gastric cancer in coal miners.     

Role of nitrosation in the mutagenic activity of coal dust: A postulation for gastric carcinogenesis in coal miners

The mutagenicity of coal dust solvent extracts with and without nitrosation was studied using the Salmonella/microsome assay system. Coal dust solvent extracts were either non-mutagenic or very weakly mutagenic with S9 activation. High mutagenic activities, however, were found when extracts of bituminous, subbituminous, and lignite coal dusts were reacted with nitrite under an acidic condition. Formation of mutagens from coal dust extracts by nitrosation was highest at pH 3.2 and decreased with increasing pH in the reaction mixture. Mutagenic activity appeared to be independent of metabolic activation. The mutagens formed from nitrosation of coal dust extracts induced frameshift mutations. The results reported here may have possible implications for the explanation of an elevated incidence of gastric cancer in coal miners.     

中华猕猴桃汁的防癌作用——(二)在体外模拟胃液中对亚硝胺合成的阻断作用—Ames试验方法检测

本文研究了猕猴桃汁对N-二甲基亚硝胺体外合成的阻断作用,以鼠伤寒沙门氏菌致突变试验检验。 将二甲基亚硝胺的前体物质-亚硝酸钠和氨基比林,在体外模拟胃液条件下(pH3.3,37％℃)保温一小时,以鼠伤寒沙门氏菌变异株TA100,按常规方法(平皿掺入试验)检验致突变性。当两种前体浓度达5mg/ml以上时,如不加阻断剂,均显示出突变阳性反应,提示反应体系中形成了有致突变性的亚硝胺。如果同时加入猕猴桃汁,可以阻断亚硝胺合成,在5mg/ml和8mg/ml两个浓度的测定结果均未出现致突变作用。在5mg/ml反应体系中,分别加入桃汁和维生素C溶液进行对比,发现桃汁的阻断效率高于维生素C,每皿菌落数均值分别为252±4.2(桃汁),和445±81.2(同浓度维生素C),两者差异有显著性(P<0.01)。结果证明猕猴桃汁对体外亚硝胺合成的阻断作用优于同浓度的维生素C溶液。同样条件下单独保温的亚硝酸钠氨基比林或磷酸缓冲液均无致突变作用。 同样条件下处理的样品(亚硝酸钠,氨基比林各5mg/ml,加到pH3.3磷酸缓冲液中,37℃混合保温1小时)经水蒸气蒸馏,二氯甲烷萃取,浓缩后用气相色谱—质谱联机分析,确认为N-二甲基亚硝胺(NDMA)。