The mutagenicities of seven coumarin derivatives and a furan derivative (nimbolide) isolated from three medicinal plants

Seven coumarin derivatives (imperatorin, heraclenin, xanthotoxin, marmesin, chelepin, oxypeucedanin, esculin) and a furan derivative (nimbolide) were screened on 6 Ames tester strains (TA92, TA94, TA97, TA98, TA100, TA102). The eight compounds are chemicals isolated from three Nigerian medicinal plants: Afraegle paniculata, Clausena anisata, and Azadirachta indica. Different preparations of the former are taken by Nigerians for gut disturbances, and a concoction of the latter called "Agbo" is taken as an antimalarial. Marmesin and imperatorin were mutagenic in all tester strains except TA94 and TA102. The mutagenicity potencies of marmesin and imperatorin were 20 and 0.2 respectively. Mutagenicity was highest in TA98 and TA100 in both compounds. Marmesin was optimally mutagenic at a dose of 1.04 micrograms, and imperatorin at 30.0 micrograms. Microsomal activation was not required for mutagenicity in both compounds.     

Mutagenicity Assay in Salmonella for Thirteen 2-Substituted-1H-phenanthro (9,10-d) Imidazoles

Abstract

Some 2-substituted-1H-phenanthro [9,10-d] imidazole compounds synthesized as a predrugs were tested in mutagenicity assays in Salmonella strains TA97, TA98, and TA100 using a plate incorporation assay both with and without S9 mix. The 10 substances were mutagenic in TA97 and five of them were mutagenic only with metabolic activation, whereas one of them did not require the addition of S9. The eight substances were mutagenic in TA98 only with S9. For TA100, seven substances showed positive results both with and without S9, however another four required S9, whereas only one of them did not required metabolic activation. In summary, all of 13 substances derived from phenanthro [9,10-d] imidazole were found to be mutagenic for at least one or two of the three strains and their mutagenicity are discussed.     

Mutagenic activity of the feces of rats following oral administration of tartrazine

After oral administration of the azo dye tartrazine, bile and feces of treated rats were investigated for mutagenicity using the Ames test withSalmonella typhimurium strains TA 98 and TA 100 with and without metabolic activation. In the presence of S 9-mix fecal extracts developed a weak but reproducible dose-related response in strain TA 100. In bile no metabolites exerting mutagenic activity were found.     

Mutagenicity of Mouriri pusa Gardner and Mouriri elliptica Martius

Mouriri pusa Gardner and Mouriri elliptica Martius are fruit-bearing plants of the Melastomataceae family, popularly known in Brazil as puçá-preto or jaboticaba-do-cerrado, and they are used in folk medicine for the treatment of gastric ulcers. In this study, we employ the Ames test to assess the mutagenicity of compounds obtained from the leaves of these species. The methanol extract of the M. pusa was mutagenic to the Salmonella typhimurium strains TA98, TA97a and TA100, with or without metabolic activation. The methanol extract of M. elliptica induced mutagenic activity in TA98 when metabolized with S9 fraction and TA97a with and without S9, but with lower mutagenicity index (MI) and potencies values than those for M. pusa. Enriched fractions of flavonoids and tannins of M. pusa were also evaluated and they demonstrated positive mutagenicity. The highest values of MI and potency were obtained with the flavonoid fraction, which contains large amounts of quercetin, quercetin glycosides and myricetin. These compounds are probably related to the mutagenicity observed in the Ames test. The dichloromethane extract was not mutagenic in any of the test conditions employed.     

Biological and chemical studies on overheated brewed coffee

Vapour formed from overheated decaffeinated coffee was condensed and tested for mutagenicity using the Ames assay in Salmonella typhimurium strains TA98 and TA100. Vapour produced at 73 and 100 degrees C exhibited no mutagenicity. The basic fraction of vapour produced at 350 degrees C showed weak mutagenicity towards strains TA98 with metabolic activation. The chemical analysis of this fraction identified pyridines and pyrazines as the major constituents. None of the compounds identified in this fraction has been reported as mutagenic when tested in the Ames assay.     

Mutagenicity and toxicity studies of p-phenylenediamine and its derivatives

The mutagenicity of p-phenylenediamine and its derivatives was tested using Ames Salmonella strains TA98 and TA100. p-Phenylenediamine was weakly mutagenic to TA98 with metabolic activation. 2-Nitro-p-phenylenediamine was directly mutagenic to both strains, while 2-methyl-p-phenylenediamine required S9 mix. All the test compounds induced a dose-related increase in chromosomal aberrations m Chinese hamster ovary (CHO) cells in the absence of the S9 mix. The mutagenicity and toxicity of these compounds did not correlate with their oxidation potentials, or any other tested physicochemical properties including the energy difference between the lowest unoccupied and the highest occupied molecular orbital, ionization potential, and dipole moment.     

Investigation of genotoxic and antigenotoxic activities of Melampodium divaricatum in Salmonella typhimurium.

Melampodium divaricatum is a member of the Asteraceae and in Brazil is known as false-calendula, its flowers being used in anti-inflammatory preparations, substituting the true calendula or marigold (Calendula officinalis L.). The flower extract was investigated for mutagenic and antimutagenic effect in the Salmonella/microsome assay. The tested extract was not mutagenic in the strains TA100, TA98, TA97a and TA102 and decreased the mutagenicity of aflatoxin B1, benzo(a)pyrene and daunomycin. Chlorophyll and triterpenes were detected in the extract, and they might have contributed to the observed effect. Our data suggest that these medicinal plants possess cancer chemopreventive properties.     

Monitoring sãto paulo state rivers in brazil for mutagenic activity using the ames test

Organic extracts of raw water from 11 water courses of São Paulo State, Brazil, were collected during one year bimonthly and tested for mutagenicity using the Ames test, with strains TA98 and TA100 of Salmonella typhimurium with and without metabolic activation. The samples were extracted with XAD₂ resin and eluted with methanol and methylene chloride. From the 75 samples analyzed, 14 showed positive responses and 8 were considered marginal, making up 29% of mutagenic samples. The percentage of mutagenic samples in October (spring) was 9%, increasing to 64% in February (summer), and decreased to 9% again in August (winter). Paraiba do Sul river showed the higher percentage of mutagenic samples (67%) and Capivari river the highest mutagenic sample (1787 and 3265 revertants per liter for TA98 without and with S9, respectively). The amplitude of the mutagenic response was 39–3265 revertants per liter for TA98 and 83–467 for TA100. The mutagenic samples showed direct and indirect mutagens, and TA98 detected the majority of responses, indicating prevalence of frameshift mutagens in these samples. © 1993 John Wiley & Sons, Inc.     

Mutagenic activity in roadside soils

Mutagenicity of soils sampled at median strips, roadsides and a park neighboring arterial roads in Kurume City was determined by Ames test. Organic extracts of soils were mutagenic in strains TA98, TA100, YG1041 and YG1042 with and without S9mix. No sample showed mutagenic responses in strains YG3003 or YG7108. Extracts from soils of median strips and beside intersections showed higher mutagenicity and concentrations of PAHs and heavy metals than others, and mutagenic activity of soils correlated significantly with concentrations of PAHs and heavy metals. However, PAHs accounted for less than 12% of total mutagenicity in strains TA98 and TA100 of soil extracts. These extracts showed much higher mutagenicity in YG strains than in TA strains. The results indicate that these soils may be polluted with nitroarenes and aromatic amines.     

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.     

Tofisopam--evaluation of mutagenic and genotoxic properties

The mutagenic properties of tofisopam, the member of the 2,3-benzodiazepine family, were evaluated on the basis of Ames test with Salmonella typhimurium TA1537, TA97, TA98, TA100 and TA102 strains. The genotoxic properties of tofisopam were estimated on L929 cell line with the cytokinesis-block technique. Under the experimental conditions, no mutagenic activity of tofisopam in tester bacteria strains was found, and no genotoxic activity was observed.     

Fruit extract of the medicinal plant Crataegus oxyacantha exerts genotoxic and mutagenic effects in cultured cells

Crataegus oxyacantha, a plant of the Rosaceae family also known “English hawthorn, haw, maybush, or whitethorn,” has long been used for medicinal purposes such as digestive disorders, hyperlipidemia, dyspnea, inducing diuresis, and preventing kidney stones. However, the predominant use of this plant has been to treat cardiovascular disorders. Due to a lack of studies on the genotoxicity of C. oxyacantha, this investigation was undertaken to determine whether its fruit extract exerts cytotoxic, genotoxic, or clastogenic/aneugenic effects in leukocytes and HepG2 (liver hepatocellular carcinoma) cultured human cells, or mutagenic effects in TA100 and TA98 strains of Salmonella typhimurium bacterium. Genotoxicity analysis showed that the extract produced no marked genotoxic effects at concentrations of 2.5 or 5 µg/ml in either cell type; however, at concentrations of 10 µg/ml or higher significant DNA damage was detected. The micronucleus test also demonstrated that concentrations of 10 µg/ml or higher produced clastogenic/aneugenic responses. In the Ames test, the extract induced mutagenic effects in TA98 strain of S. typhimurium with metabolic activation at all tested concentrations (2.5 to 500 µg/ml). Data indicate that, under certain experimental conditions, the fruit extract of C. oxyacantha exerts genotoxic and clastogenic/aneugenic effects in cultured human cells, and with metabolism mutagenicity occurs in bacteria cells.     

Mutagenicity and chemopreventive activities of Astronium species assessed by Ames test

In the neotropical savannah, Astronium species are used in popular medicine to treat allergies, inflammation, diarrhea and ulcers. Given that natural products are promising starting points for the discovery of novel potentially therapeutic agents, the aim of the present study was to investigate the mutagenic and antimutagenic activities of hydroalcoholic extracts of Astronium spp. The mutagenicity was determined by the Ames test on Salmonella typhimurium strains TA98, TA97a, TA100 and TA102. The antimutagenicity was tested against the direct-acting and indirect-acting mutagens. The results showed that none of the extracts induce any increase in the number of revertants, demonstrating the absence of mutagenic activity. On the other hand, the results on the antimutagenic potential showed a moderate inhibitory effect against NPD and a strong protective effect against B[a]P and AFB₁. This study highlights the importance of screening species of Astronium for new medicinal compounds. The promising results obtained open up new avenues for further study and provide a better understanding the mechanisms by which these species act in protecting DNA from damage. However, further pharmacological and toxicological investigations of crude extracts of Astronium spp., as well as of its secondary metabolites, are necessary to determine the mechanism(s) of action to guarantee their safer and more effective application to human health.     

Mutagenic activity promoted by amentoflavone and methanolic extract of Byrsonima crassa Niedenzu

Byrsonima crassa is a plant pertaining to the Brazilian central savannah-like belt of vegetation and popularly used for the treatment of gastric dysfunctions and diarrhoea. The methanol extract contains catechin, tannins, terpenes and flavonoids; both mutagenic potential and antioxidant properties have been ascribed to flavonoids. The mutagenicity of some flavonoids is believed to be associated with the formation of reactive oxygen species and seems to depend on the number and position of hydroxyl groups. In the present study the mutagenic activity of the methanol, chloroform and 80% aqueous methanol extracts, as well as acetate and aqueous sub-fractions, of this medicinal plant were evaluated by Salmonella typhimurium assay, using strains TA100, TA98, TA102 and TA97a, and in mouse reticulocytes. The results showed mutagenic activity of the methanolic extract in the TA98 strain without S9, but no mutagenicity to mouse cells in any of the extracts. The acetate fraction showed strong signs of mutagenicity without S9, suggesting that in this enriched fraction were concentrated the compounds that induced mutagenic activity. The aqueous fraction showed no mutagenic activity. The TLC and HSCCC analyses of the acetate fraction with some standard compounds permitted the isolation of the quercetin-3-O-beta-D-galactopyranoside, quercetin-3-O-alpha-L-arabinopyranoside, amentoflavone, methyl gallate and (+)-catechin, of which only the amentoflavone exhibited positive mutagenicity to TA98 (+S9, -S9).     

Ames试验检测十种中药有效成份和制剂的诱变性

本文以Ames实验室最新推荐的四株测试菌株(TA97、TA98、TA100、TA102)、用予培养法对斑蝥酸钠、去甲斑蝥素、三尖杉酯硷、高三尖杉酯硷、蒿甲醚、芫花酯甲、芫花酯乙等十种中药有效成份制剂进行了诱变性的研究。 结果表明,十种中药有效成份和制剂在加和不加S_9混合液情况下,均来显示诱变性。 用体外致突变试验方法对提取的中药有效成份进行检测,了解其潜在的遗传毒性是十分必要的。     

Screening of medicinal plants used in South African traditional medicine for genotoxic effects

Dichloromethane and 90% methanol extracts from 51 South African medicinal plants were evaluated for potential genotoxic effects using the bacterial Ames and VITOTOX tests with and without metabolic activation. Dichloromethane extracts from bulbs of Crinum macowanii showed mutagenicity in strain TA98 with and without metabolic activation, whereas extracts from leaves of Chaetacme aristata and foliage of Plumbago auriculata showed mutagenicity and/or toxicity. Extracts from the leaves of Catharanthus roseus and twigs of Combretum mkhzense were mutagenic with metabolic activation only. The only 90% methanol extracts that were mutagenic in strain TA98 were from the leaves of C. roseus and Ziziphus mucronata in the presence of metabolic activation. No genotoxic effects were found in strain TA100 or in the VITOTOX test.     

Mutagenicity of environmental samples from an industrialized area of the Rio de la Plata Estuary using the salmonella/microsomal assay

Mutagenic characterization was applied to study the environmental compartments of a heavily industrialized area. Polycyclic aromatic hydrocarbons have been previously detected in the environmental samples of different compartments. Salmonella typhimurium strains TA98 and TA100 were used for screening the mutagenic activity of airborne particulate matter, sediments, surface waters, and industrial wastewaters. The tests were performed with and without S9 metabolic activation. Results of the tests showed mutagenicity in those assays with metabolic activation. Sampling points with higher activity reached a value of 25,258/44,106 His+ rev/g in airborne particulate matter samples and 8,549,500/5466 His+ rev/L water samples, for strains TA98 and TA100, respectively, and 15,128 His+ rev/g in sediment samples for TA98. Apparently, a strong mutagenicity in water and sediment samples is associated with sectors near point sources of pollution. © 1996 by John Wiley & Sons, Inc.     

Ames mutagenicity tests of products from a heated potato-starch system

A charred sample was prepared from potato starch heated with ammonium carbonate at 600°C in a flask under a nitrogen stream. The water produced was collected and extracted with methylene chloride. The basic fraction obtained from the extract exhibited strong mutagenicity in Ames assays using Salmonella typhimurium strains TA98 or TA100 with metabolic activation (rat-liver S-9 mix). The basic fraction was further fractionated by silica gel column chromatography and subsequently by Scphadex column chromatography. Some of the resulting fractions exhibited strong mutagenic activities in S. typhimurium strain TA98 with S-9 mix.     

Mutagenicity and clastogenicity evaluation of metaphenoxy benzyl chloride by ames and micronucleus assays

Metaphenoxy Benzyl Chloride (3-PBC; CAS # 53874-66-1) is a commonly used intermediate in organic synthesis and is a widely used chemical building block. There is likelihood of human contact with 3-PBC in the process of organic or pesticide synthesis and even through as impurity in the product. Further, this chemical has been reported to be found in water reservoirs causing a threat to aqueous flaura and fauna. Genotoxic alert has been suspected for the chemical 3-PBC based on its structure hence, the impetus of present work was to assess the mutagenic potential of 3-PBC using Ames bacterial reverse-mutation assay and in vitro micronucleus assay. 3-PBC was tested for mutagenic potential at six different concentrations, with 0.05 (without metabolic activation) and 0.50 (with metabolic activation) µL/plate as the highest concentrations, followed by five lower concentrations with 2-fold spacing. In clastogenic evaluation, 3-PBC was tested at concentrations ranged from 0.31 to 4.88?µL/mL to assess micronucleus induction in mammalian cells viz. Chinese Hamster Ovarian-K1 cells (CHO-K1 cells). In the Ames assay, 3-PBC did not show mutagenicity in all five tester strains of Salmonella typhimurium viz. TA98, TA100, TA102, TA1535 and TA1537 both in the presence and absence of a metabolic activation system and found to be nonclastogenic when evaluated in “CHO-K1 cells”.     

Mutagenic properties of 1,2,3,4-tetrahydronaphthaline-1-hydroperoxide, a model compound for organic peroxides in Diesel exhaust

The genotoxicity of the organic peroxide 1,2,3,4-tetrahydronaphthaline-1-hydroperoxide (or tetraline-1-hydroperoixde, THP) was investigated in the Ames assay without a metabolic activating system using Salmonella typhimurium strains TA 98, TA 100, and TA 102. THP served as a model compound for higher organic peroxides, which can arise from autoxidation of hydrocarbons, e.g. in Diesel exhaust. While THP induced no mutagenic response in S. typhimurium TA 98, it was directly mutagenic in strains TA 100 and TA 102. These data, along with findings on mutagenic properties of other alkyl hydroperoxides, suggest that such compounds deserve further investigation regarding their genotoxic potential and occurrence in the environment. Received: 1 October 1997 / Accepted: 20 January 1998