Evaluation of the antimutagenic and antiradical potentials of extracts from the tubers of (Tunisian) Cyperus rotundus

The mutagenic potential of aqueous, total oligomers flavonoids (TOF), ethyl acetate and methanol extracts from tubers of Cyperus rotundus L. was assessed using Ames Salmonella tester strains TA98 and TA100, and SOS chromotest strain Escherichia coli PQ37 with and without metabolic activation (S9). None of the different extracts produced a mutagenic effect. Likewise, the antimutagenicity of the same extracts was tested using the “Ames test” and the “SOS chromotest”. Our results showed that C. rotundus extracts possess antimutagenic effects against S. typhimurium TA98 and TA100 strains towards the mutagen aflatoxin B1 (AFB1), similar to E. coli PQ37 strain against AFB1 and Nifuroxazide mutagens using the SOS chromotest assay. A free radical scavenging test was used in order to explore the antioxidant capacity of the extracts obtained from the tubers of C. rotundus. TOF, ethyl acetate and methanol extracts showed an important free radical scavenging activity towards the 1,1-diphenyl-2-picrylhydrazine (DPPH) free radical. These extracts showed an IC50 value of respectively 5, 20 and 65?µg?mL^?1. The beneficial effects of TOF, ethyl acetate and methanol extracts of C. rotundus were assessed by antioxidant and antimutagenic activities.     

Synthesis and biological activities of new azacrown ether Schiff bases and spectrophotometric studies of their complexation with [60]fullerene

A series of novel azacrown ether Schiff bases 1–3 have been synthesized in good yield and in a simple way. Their host–guest interaction with [60]fullerene has been studied in toluene by absorption spectroscopic method. All the complexes are found to be stable with 1:1 stoichiometry. Because of their potential applications in industry, agriculture and medicine, they were investigated for their mutagenic and antimutagenic activities using the spot test and the plate incorporation assay of Ames. Compounds 1, 2 and 3 were found to be nonmutagenic in the Ames test using strains TA 1535, TA100 and TA97a of Salmonella typhimurium. However, using strain TA102 revealed that, although both compounds 1 and 2 were nonmutagenic, compound 2 gave a positive response indicating that it acts as an oxidative mutagen. The structure-activity relationship may throw some light on the biological activity of such series of compounds.     

Chemopreventive effects of ellagic acid against genotoxicity induced by benzo(a)pyrene

Benzo(a)pyrene (B(a)P) is a commonly used indicator for polycyclic aromatic hydrocarbons (PAHs) contamination. The use of certain phytochemicals and some polyphenolic compounds proved to be effective in blocking PAH-induced effects. The aim of the present study was to examine the possible inhibitory effects of ellagic acid (EA), present in berries and nuts, against B(a)P-mediated toxicity using in vitro and in vivo test systems. In vitro method included the Ames test, using Salmonella typhimurium tester strain TA100. In vivo experiments were based on mouse bone marrow micronucleus (MN) assay and immunoblotting. EA produced a decrease in the number of revertant colonies against B(a)P in the Ames assay. Further, there was a reduction in the mean number of micronucleated polychromatic erythrocytes in the presence of EA in the co-treatment protocol of the MN test. Western blotting results showed downregulation of CYP450 isoform CYP1A1 which prevented bioactivation of B(a)P. Thus, the present study demonstrates antimutagenic role played by EA against the mutagenic activity of B(a)P in both in vitro and in vivo systems.     

Antimutagenic and bacteriostatic activities of Schiff‐base compounds derived from aminoguanidine,semicarbazone and thiosemicarbazone and a copper(II)‐coordination complex

The Schiff‐base aminoguanidine compounds including a resorcylidene aminoguanidine copper(II) complex that were synthesized at our laboratory posses non‐mutagenic properties when tested with Ames test using Salmonella typhimurium TA97, TA100 and TA102 bacterial strains. These compounds were tested as possible pharmacological agents in preventing a wide array of illnesses. Additionally, some of these compounds exhibit strong antimutagenic and bacteriostatic activity. Nitrovin, a known mutagen, was used in the antimutagenicity tests as the inducer. A three‐dimensional projection of the copper(II) complex was derived by the semi‐empirical method ZINDO/1 to obtain additional information about its structure, and to help elucidate a possible mechanism of action.     

Genotoxicity,antifungal and antibacterial activity of newly synthesized N-(3-phthalidyl)amines and o-benzoyl benzamide derivatives

A number of newly synthesized phthalidylamines and o-benzoylbenzamide derivatives were evaluated for some biological activities. Synthesis was established by condensation of 3-acetoxyphthalide 1 with morpholine, piperidine, N,N-diisobutyl-N,N-dibenzylamines and piperazine, which afforded N-(3-phthalidyl)amines 3a–d, and 4 respectively, while with N,N-diisopropylamine, o-formyl-N,N-diisopropyl benzamide 5a is formed exclusively. On the other hand, the reaction of 3-acetoxy-3-phenylphthalide 2 with secondary amines afforded o-benzoylbenzamide derivatives 5b–c, 6 in a high yield. The structure of the reaction products was established from their spectral data. These products were screened for antifungal, antibacterial and genotoxic effect. It was found that all tested compounds have antifungal activity. Compounds 1, 2, 3d and 5b were found to be active against Escherichia coli, Bacillus subtilis and Staphylococcus aureus. Genotoxic effects using Ames test showed that Compounds 1 and 2 have a weak base-pair substitution mutagenicity while a clear base-pair substitution mutagenic activity was shown by 3a using TA100-strain of Salmonella typhimurium. Compound 4 showed a frameshift mutgenicity while a weak oxidative mutagenic action was revealed by 6. No change on the mutagenicity of the tested chemicals was observed after using the S9 metabolic activation system.     

Antimicrobial activities of extracts from tropical Atlantic marine plants against marine pathogens and saprophytes

Studies investigating disease resistance in marine plants have indicated that secondary metabolites may have important defensive functions against harmful marine microorganisms. The goal of this study was to systematically screen extracts from marine plants for antimicrobial effects against marine pathogens and saprophytes. Lipophilic and hydrophilic extracts from species of 49 marine algae and 3 seagrasses collected in the tropical Atlantic were screened for antimicrobial activity against five ecologically relevant marine microorganisms from three separate kingdoms. These assay microbes consisted of the pathogenic fungus Lindra thalassiae, the saprophytic fungus Dendryphiella salina, the saprophytic stramenopiles, Halophytophthora spinosa and Schizochytrium aggregatum, and the pathogenic bacterium Pseudoaltermonas bacteriolytica. Overall, 90% of all species surveyed yielded extracts that were active against one or more, and 77% yielded extracts that were active against two or more assay microorganisms. Broad-spectrum activity against three or four assay microorganisms was observed in the extracts from 48 and 27% of all species, respectively. The green algae Halimeda copiosa and Penicillus capitatus (Chlorophyta) were the only species to yield extracts active against all assay microorganisms. Among all assay microorganisms, both fungi were the most resistant to the extracts tested, with less than 21% of all extracts inhibiting the growth of either L. thalassiae or D. salina. In contrast, over half of all lipophylic extracts were active against the stramenopiles H. spinosa and S. aggregatum, and the bacterium P. bacteriolytica. Growth sensitivity to hydrophilic extracts varied considerably between individual assay microorganisms. While 48% of all hydrophilic extracts were active against H. spinosa, 27% were active against P. bacteriolytica, and only 14% were active against S. aggregatum. Overall, more lipophilic extracts inhibited microbial growth than hydrophilic extracts. The variability observed in the antimicrobial effects of individual extracts against each assay microorganism reflects the importance of choosing appropriate test microbes in assays from which ecologically relevant information is sought. Results from this survey demonstrate that antimicrobial activities are prevalent among extracts from marine algae and seagrasses, suggesting that antimicrobial chemical defenses are widespread among marine plants.     

Mutagenicity of diesel engine exhaust in the Ames / Salmonella assay using a direct exposure method

The aim of this study was to investigate the potential mutagenic activity of diesel engine exhaust in the Ames/Salmonella assay using a direct aerosol exposure system. So, TA 98 and TA 100 strains, with or without added S9 mix, were exposed to diesel emissions after varying degrees of filtration. Variants of these two strains, deficient in nitroreductase (TA 98NR and TA 100NR) or over-expressing O-Acetyl Transferase (YG 1024 and YG 1029), were also exposed to total (unfiltered) diesel exhaust to highlight the putative mutagenicity of any nitro-PAHs present in these emissions. Mutagenic activity of the diesel exhaust was demonstrated on Salmonella typhimurium, strains TA 100 and variants TA 100 NR and YG1029. The use of a particle filter did not modify the genotoxicity of the diesel emissions, indicating a major contribution of the gas phase to the mutagenicity of these diesel emissions. The prominent role of the particulate-associated nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) claimed by some authors working on diesel exhaust organic extracts was not confirmed by our results with native diesel exhaust exposure. Our results show that the gas phase is potentially more mutagenic than the particles alone.     

Mutagenicity of polyaromatic hydrocarbons by chemical models for cytochrome P450 in Ames assay

DNA damage is an important step in carcinogenesis. The Ames assay is a short-term screening of carcinogens that induce DNA damage. Most carcinogens require enzymatic activation through oxidation by cytochrome P450 (CYP450) in the presence of S9 mix. A combination of iron (Fe)(III) porphyrin and an oxidant is also able to oxidize compounds as an alternative metabolic pathway to CYP450. Previously it was reported that a chemical model containing a water-soluble 5,10,15,20-tetrakis(1-methylpyridinium4-yl)porphyrinatoiron(III) chloride (4-MPy) and tert-butyl hydroperoxide (t-BuOOH) activated aromatic amines and amides. In this study, a chemical model composed of an Fe porphyrin, water-insoluble 5,10,15,20-tetrakis(pentafluorophenyl)porphyrinatoiron(III) chloride (F₅P) or water-soluble 4-MPy was optimized with an oxidant – t-BuOOH, magnesium monoperoxyphthalate (MPPT), or iodosylbenzene (PhIO). Subsequently the mutagenicity of benzo[a]pyrene (B[a]P) and chrysene in Salmonella typhimurium TA strains was compared. B[a]P was activated by a combination of F₅P or 4-MPy plus MPPT or PhIO in S. typhimurium TA1538. The B[a]P-induced mutagenicity with F₅P plus oxidant was higher than 4-MPy plus oxidant. Mutagenicity of chrysene, a tetracyclic aromatic hydrocarbon, was not detected in the presence of F₅P/PhIO in S. typhimurium TA98, but was activated in the presence of F₅P/MPPT. The F₅P/MPPT activated other polyaromatic hydrocarbons (PAH) in the S. typhimurium TA98 assay including dibenz[a,c]anthracene, dibenz[a,h]anthracene, 3-methylcholanthrene, and benzo[a]anthracene. The results indicated that the F₅P/MPPT was the most efficient model for detecting PAH-induced mutagenicity in the Ames assay.     

Antimicrobial activities of extracts from Indo-Pacific marine plants against marine pathogens and saprophytes

This study is the second of two surveys designed to systematically screen extracts from marine plants for antimicrobial effects against ecologically relevant marine microorganisms, and to compare results on a geographical basis. In the preceding survey, extracts from tropical Atlantic marine algae and seagrasses were screened in growth inhibition assays against the pathogenic fungus Lindra thalassiae, the saprophytic fungus Dendryphiella salina, the saprophytic stramenopiles, Halophytophthora spinosa and Schizochytrium aggregatum, and the pathogenic bacterium Pseudoaltermonas bacteriolytica. In this study, the same assay microorganisms were used to examine the antimicrobial effects of lipophilic and hydrophilic extracts from 54 species of marine algae and two species of seagrasses collected from Indo-Pacific reef habitats. Overall, 95% of all species surveyed in this study yielded extracts that were active against one or more, and 77% yielded extracts that were active against two or more assay microorganisms. Broad-spectrum activity against three or four assay microbes was observed in the extracts from 50 to 21% of all species, respectively. Extracts from the green alga Bryopsis pennata and the red alga Portieria hornemannii inhibited the growth of all assay microorganisms. Given that antimicrobial activity was prevalent among extracts of Indo-Pacific marine plants, it is interesting to note that the inhibitory effects of each extract varied considerably between the assay microorganisms. Overall, H. spinosa and D. salina were the most susceptible while L. thalassiae, S. aggregatum, and P. bacteriolytica were the most resistant to the extracts tested. These results provide good evidence that antimicrobial chemical defenses are widespread among Indo-Pacific marine plants. Further, the activity profiles of plant extracts suggest that antimicrobial secondary metabolites can have pathogen-selective or broad-spectrum effects. To confirm these results, chemical studies will be needed to isolate and characterize the compounds responsible for the observed antimicrobial activities.     

Larvicidal potential of different solvent extracts and oleanolic acid derivative from Coccinia indica against vector mosquitoes

The mosquito larvicidal activities of different solvent extracts (chloroform, ethyl acetate, and methanol) from the leaves of Coccinia indica were studied. Among the extracts tested, the methanol extract showed the highest larvicidal activity against early fourth instar larvae of Culex quinquefasciatus (LC₅₀?=?142?mg?L^?1), Aedes aegypti (LC₅₀?=?158?mg?L^?1) and Anopheles stephensi (LC₅₀?=?161?mg?L^?1) after 24?h of exposure period. The lowest larval mortality was observed with the ethyl acetate extract with the LC₅₀ values of 927, 872, and 730?mg?L^?1 against Cx. quinquefasciatus, Ae. aegypti, and An. stephensi, respectively. The chloroform extract showed the moderate larvicidal activity against the mosquito species tested with the LC₅₀ values from 446 to 546?mg?L^?1. A new triterpene was isolated from the methanol extract using bio-assay guided separation and identified as an oleanolic acid derivative by NMR, IR and mass spectral studies. The compound showed prominent larvicidal activity against Cx. quinquefasciatus, Ae. aegypti and An. stephensi with the LC₅₀ values of 5.6, 5.0, and 4.8?mg?L^?1, respectively. The results of the present investigation offer an opportunity for developing alternatives to rather expensive and environmentally hazardous organic insecticides.     

Nitropyridoindoles—Formation,characterization and mutagenicity

Nitration of pyridoindoles (β‐carbolines) was carried out using different nitration methods and structural assignments of these nitro compounds were made using different spectroscopic techniques. The mutagenic activity of these nitro derivatives was studied using Salmonella typhimurium strains TA 98 NR and TA 100 NR in the absence as well as in the presence of S‐9 mix. Only trinitro derivatives were found to be highly mutagenic to strain TA 98 NR.     

Bacterial toxicity testing and antibacterial activity of parabens

Parabens are used because of their antimicrobial effects, yet they have multiple adverse effects. The aim of this work was to evaluate the bactericidal activity and bacterial toxicity of the most common parabens: methylparaben, ethylparaben, propylparaben, isopropylparaben, butylparaben, isobutylparaben and phenylparaben. The bactericidal action was evaluated by means of the dilution-neutralization method against Escherichia coli and Staphylococcus aureus, and the biotest of inhibition of growth of E. coli was applied for the bacterial toxicity assay. Bactericidal concentrations were reached only for propylparaben, butylparaben and isobutylparaben. The toxicity study showed methylparaben to be the least toxic, whereas the most toxic one was phenylparaben. It can be concluded that the disinfectant activity of the parabens studied is insignificant against S. aureus and E. coli. Acute toxicity is very low, and the inhibitory effect is weak. Our results provide information about the risk–benefit balance of parabens use.     

Synthesis and antimicrobial activity of esters of 3-ethoxy-4-hydroxybenzaldehyde oxime

A series of oxime esters was synthesized by esterification of 3-ethoxy-4-benzaldehyde oxime with acid chlorides in the presence of triethylamine. They were evaluated for their in vitro antifungal activity against three pathogenic fungi, namely Rhizoctonia bataticola, Fusarium udum, and Alternaria porii, and their antibacterial activity against the three bacterial strains Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoneae. The compounds bearing medium-length alkyl chains showed greater activity than those with long alkyl chains. An electron-donating group in para position of the aryl ring confers highest activity.     

Bacteriological quality assessment of drinking water available at the flood affected areas of Peshawar

Monsoon flooding occurred in the main areas of the Khyber Pakhtunkhwa, Punjab, and Balochistan as well as parts of Gilgit Baltistan of Pakistan and Azad Jammu Kashmir in July 2010. Water-borne diseases such as cholera, enteric fever, and dysentery were common among the inhabitants of flood-affected areas which were selected for sample collection. In the present study, 10 sites in District Peshawar were selected and drinking water samples collected. These samples were analyzed for the total plate count (TPC), total coliform bacteria (TCB), total fecal coliform bacteria (TFCB), Escherichia coli (EC), Pseudomonas aeruginosa (PA), Vibrio cholerae (VB), Salmonella Shigella, and Staphylococcus aureus. The TPC ranged from 8 × 10¹ to 7 × 10⁴ CFU/ml. The TCB ranged from <1.1 to 280 MPN/100 ml. Twenty percent of the samples were contaminated with TFCB, EC, Salmonella, Shigella, and Staphylococcus aureus, while only one sample contaminated with PA. Forty percent of the samples were contaminated with VB. The surface and well water was greatly contaminated by flooding and major improvements on priority basis are essential.     

Modification of mutagenic activity of benzo[a]pyrene by trace elements in the Ames assay

Benzo[a]pyrene (BaP) is one of the most ubiquitous environmental contaminants and exerts potent carcinogenicity and mutagenicity. In the presence of rat liver S9 mix, four trace elements, germanium (Ge), iron (Fe), zinc (Zn), and molybdenium (Mo), were included in the Ames Salmonella microsome/mutagenic assay to test their inhibitory effects on BaP-induced mutations. All trace elements were found to exert an inhibitory effect in tester TA98 and TA100 strains; Fe was the most potent among the elements tested, whereas Zn was weakly inhibitory to prevent mutations. The present findings demonstrate that the antimutagenic potential of trace elements, notably Fe, may be attributed to its modulatory effect on the bioactivation and detoxification processes of BaP.     

Evaluation of the larvicidal efficacy of extracts from three plants and their synergistic action with propoxur against larvae of the filarial vector Culex quinquefasciatus (Say)

Petroleum ether extracts of Piper longum, Curcuma aromatica, and Ocimum basilicum were tested for their larvicidal activity against Culex quinquefasciatus, a filarial vector using WHO standard procedures. Among the three plants, extract of P. longum was found to be highly effective with LC₅₀ and LC₉₀ being 0.89 and 1.49 ppm, respectively. C. aromatica also showed significant larvicidal activity with LC₅₀ and LC₉₀ being 11.41 and 17.36 ppm, respectively. The LC₅₀ and LC₉₀ for O. baslicum were 76.67 and 200.56 ppm, respectively. Propoxur, a carbamate was also studied for its larvicidal activity, which showed LC₅₀ to be 0.09 ppm and LC₉₀ to be 0.16 ppm. Synergistic studies of all three plant extracts with propoxur revealed P. longum as a more efficient synergist with synergistic factor (SF) of 4.13 for LC₅₀ value and 1.68 for LC₉₀. Both C. aromatica and O. basilicum exhibited antagonistic activity at their respective LC₉₀ values with propoxur. At 1 : 1 ratio of the phytoextracts and propoxur, P. longum and C. aromatica showed synergism whereas O. basilicum displayed additive effect. Thus, P. longum was found to be a better larvicidal and synergistic agent at all tested ratios. Evidence indicates that mixed formulations of phytoextracts with insecticides might reduce the concentration of the chemicals to be applied for vector control.     

Extraction,chemical compositions,and cytotoxic activities of essential oils of Thevetia peruviana

Abstract

In this study, The essential oil of flowers, fruits, and leaves of Thevetia peruviana, which were collected in Vietnam, were being reported for the first time. The essential oil of flowers was extracted by different methods: n-hexane extraction, distillation water, and supercritical CO₂ extraction. The compositions of essential oil of different parts of Thevetia peruviana were analyzed by GC-FID and GC/MS systems. Major chemical compositions of essential oil were identified as monoterpenes, sesquiterpenes, terpenoids, and sterol. The activities of total essential oil extracts of the Thevetia peruviana exhibit inhibitory activities against five cancer cell lines.     

Combined sorptional–photocatalytic remediation of dyes by polyaniline Zr(IV) selenotungstophosphate nanocomposite

A polyaniline Zr(IV) selenotungstophosphate nanocomposite was prepared via sol-gel method and characterized by thermogravimetric analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The combined sorptional–photocatalytic activity of the nanocomposite for degradation of methylene blue and malachite green was investigated and was found to be more efficient than separate adsorption in the dark followed by photocatalysis. The dyes were degraded in 3 h by 96% and 89% by the combined process, as compared to 86% and 72% by the two-step process in 5 h. The nanocomposite material showed antimicrobial activity against Staphylococcus aureus and Escherichia coli.     

Chemical composition and antifungal activity of Chelidonium majus extracts – antagonistic action of chelerythrine and sanguinarine against Botrytis cinerea

This study discusses the similarities and differences between the antifungal activity of Chelidonium majus L. extracts and chelerythrine/sanguinarine, the main alkaloids in these extracts, against the plant pathogenic fungus, Botrytis cinerea. The obtained data show that the Ch. majus L. extracts inhibit the growth of B. cinerea very effectively. The extracts activity is significantly greater than that of chelerythrine/sanguinarine standard solutions alone and it does not always reflect the total content of alkaloids in the extracts. It has been proved that B. cinerea exhibits very diverse resistance to chelerythrine and sanguinarine. The IC₅₀ values for chelerythrine and sanguinarine equal 5.41?mg/mL and 1.76?mg/mL, respectively. In the mixture the antifungal activity of chelerythrine and sanguinarine is antagonistic in the concentration dependent way. Based on the presented data it is not clear, however, which alkaloids present in the Ch, majus extracts at significantly lower concentration levels enhance the activity of chelerythrine and sanguinarine so that the extracts activity is considerably greater than that of both main alkaloids mixtures.     

Polyphenol contents of five of medicinal plants from Cameroon and effects of their extracts on antioxidant capacities of human breast cancer cells

The aim of the study was to investigate the antiproliferative properties of extracts of five plants on breast cancer cells (MDA-MB-231) and their effects on antioxidant activities. The total phenol contents of the extracts were determined to establish a correlation to their antiproliferative effects which were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability assay. Enzymes involved in oxidative stress were also determined. Total polyphenol contents of the five extracts varied from 170 to 440 mg L^?1 of gallic acid per mg of extract with the highest value for the extract of Sida cordifolia. Cell growth inhibition was observed within 24 h, with inhibitory concentration values ranging from 7.3 to 25 mg L^?1 depending on plant extract. At concentrations between 100 and 200 mg L^?1, all the extracts exhibited significant reduction of cell proliferation in time-dependent and linear manner. The activities of superoxide dismutase and catalase of cells treated for 24 h with the extract of S. cordifolia were 3.5 U per mg protein and 8 mole H₂O₂ consumed per min per mg protein higher than those of cells treated with an extract of Viscum album.