Uc browser samsung gt ei download · Eduardo mallea pdf editor · kitltsi tmutat pdf · Janome digitizer software download · Download video lclr . The EnGen Mutation Detection Kit provides reagents for detection of on-target genome editing events. CRISPR/Cas9, TALENs, Zinc-finger Nucleases) are amplified using Q5 Hot Start High-Fidelity 2X Master Mix. In the second step, annealed PCR products are digested with EnGen T7. Caribbean Island Hopping – St Kitts, Nevis and St Maarten . TV & Radio Presenter, dream chaser, writer and a BRCA 1 gene mutation carrier /
|Country:||Sao Tome and Principe|
|Published (Last):||25 August 2012|
|PDF File Size:||11.14 Mb|
|ePub File Size:||1.49 Mb|
|Price:||Free* [*Free Regsitration Required]|
DNA damage protective effect of honey-sweetened cashew apple nectar in Drosophila melanogaster.
Book Die Byzantinische Literatur Vom 6 Jahrhundert Bis Zum Fall Konstantinopels 1453
The modulating effects of honey-sweetened cashew apple nectar HSCANon somatic mutation and recombination induced by ethyl methanesulfonate EMS and mitomycin C MMC were evaluated with the wing spot test in Drosophila melanogaster using co- and post-treatment protocols.
Similar results were also observed with honey on MMC mutagenic activity. Cashew apple pulp was effective in exerting protective or enhancing effects on the MMC mutagenicity, depending on the administration protocol and concentration used.
The ingestion of dietary components that decrease DNA damage accumulation may be an effective strategy for either the modulation or the inhibition of the carcinogenic process Pingitore et al. Hence, it is essential not only to assess safety and efficacy of candidate chemopreventive agents in preclinical models and in humans, but also to understand their mechanisms of action Brown et al.
Fruits and their derivatives, such as juices, are complex mixtures of chemicals. Therefore, considerable attention has been given to the antimutagenic agents that occur naturally or are added to foods and beverages for human consumption Ben Sghaier et al.
The formulation of mixed beverages or the addition of components to improve functional properties, such as cashew apple nectar sweetened with honey Silva et al. A number of antimutagenic and anticancer substances that occur in nature, such as phenolic compounds, are found in cashew apple Melo-Cavalcante et al. The beneficial effects of these compounds are partly attributed to their antioxidant activity.
In the present study, the Drosophila wing somatic mutation and recombination test SMARTalso known as the Drosophila wing-spot test, was used to evaluate the antimutagenic activity of honey-sweetened cashew apple nectar HSCAN on DNA damage induced by ethyl methanesulphonate EMS and mitomycin C MMCtwo known mutagenic compounds amply used as positive controls in antimutagenic studies Santos et al.
Additionally, the protective activity of two components of HSCAN, cashew apple pulp and honey, was also evaluated. This bioassay allows the simultaneous detection and quantification of mitotic recombinations versus gene and chromosomal mutations de Andrade et al.
The mutagen doses used were established in previous pilot studies conducted in our laboratory to accurately evaluate antimutagenicity of HSCAN and other compounds. The standard ST cross flies were used for the wing spot test following the methods described in Graf et al. Information on the genetic markers is given by Lindsley and Zimm After 3 days, the larvae were collected from these bottles with tap water strained through a fine-meshed stainless steel strainer and then used for the treatments.
Three-day-old larvae were placed in equal batches into plastic vials containing 1. The genotoxins concentrations were based on previous studies Abraham and Graf, ; Clements and Vogel, ; Santos et al.
For the negative controls, the larvae were transferred to a medium prepared with distilled water. Both control and treated larvae were allowed to feed on the medium for the rest of their development, which corresponds to approximately 48 h Graf and van Schaik, The 3-day-old larvae were initially distributed into plexiglass tubes, with bottom ends covered with fine nylon gauze.
These tubes were then placed into mL beakers containing 0. The larvae fed through the gauze on water-cellulose solution, on 46 mM EMS-cellulose solution for 3 h, or on 0. The two groups submitted to acute feeding with water or genotoxins were then washed and transferred to several vials containing 1.
The ST cross produced two types of progeny that were distinguished phenotypically based on the Bd S marker: Wings of females and males of the two genotypes were mounted on slides and scored under magnification for the occurrence of spots.
By comparing these two genotypes, it was possible to quantify the recombinagenic and mutagenic activities of each treatment de Andrade et al. The frequencies of each type of mutant clones per fly of a treated series were compared pair-wise i. Because of the weak expression of the flr 3 marker in small clones and its lethality in large clones of mutant cells Graf,only the mwh clones mwh single and mwh twin spots were used to calculate the clone formation frequencies per 10 5 cells.
These values were then employed to estimate the contribution of recombination and mutation to the incidence of total mutant spots per fly in trans-heterozygous flies de Andrade et al. The data obtained in two individual experiments with each genotoxin EMS and MMC were pooled, since no statistical differences were found.
Tables 1 and 2 demonstrate that EMS and MMC were genotoxic and produced significant increases in all categories of spot in both genotypes compared to their respective negative controls. These results are consistent with previously reported studies, confirming mitotic recombination as the prevalent genotoxic event induced by these genotoxins, using the SMART assay Table 3 Santos et al.
Induction frequencies corrected for spontaneous incidence estimated from the negative controls. Calculated according to Abraham In this treatment the frequency of small and large single spots were also significantly reduced in both genotypes. Table 3 also shows the proportion of mitotic recombinations and somatic mutations calculated based on the clone induction frequencies per 10 5 cells per cell division obtained for the two genotypes.
For all treatments, mitotic recombination was the most prevalent mechanism involved in mutant clone induction. The decrease in clone induction frequency varied between The response observed in the post-treatment protocols was quite different Table 2.
No differences were observed in the other treatments, which presented inconclusive or negative results. Additionally, Table 2 shows that the incidence of small and large single spots, as well as of twin spots increased or diminished, depending on the treatment. In a previous study by our research group, HSCAN and its constituents were assessed in vitroto analyze their chemical properties and antioxidant potential, and in vivousing the SMART to investigate their mutagenic activity.
Similar results were found for honey co-treatment, which protected against MMC mutagenicity and, differently from cashew apple pulp, increased the frequency of mutations when post-administered.
Moreover, it seems to interfere with the repair mechanisms involved in the MMC and EMS-induced DNA damage, increasing the incidence of mutations and recombinations, respectively. The same behavior was observed for honey and cashew apple pulp in relation to MMC.
These results are in line with literature, in which cashew apple juice was found to have mutagenic, radical-trapping, antimutagenic, and comutagenic activity Melo-Cavalcante et al. AFB1-induced mutagenesis was suppressed in Salmonella strain TA when applied in co- and post-treatment, suggesting a modulatory activity on error-prone DNA repair and an interaction with S9 enzymes and metabolization to non-mutagenic compounds of AFB1 Melo-Cavalcante et al.
In pre-treatment experiments with strains TA and TA, fresh juice showed high antimutagenic activity against MMS but, conversely, co-treatment with fresh and processed juices enhanced MMS mutagenicity. A protective effect of cashew apple juice was likewise detected in the TA strain against mutation induced by hydrogen peroxide in co- and post-treatments.
Mutagenic and antimutagenic evaluations with frozen cashew apple were also performed in eukaryotic cells of Saccharomyces cerevisiae yeast Spada et al. Additionally, the antigenotoxic and anticlastogenic effects of cashew apple juice were assessed in the genotoxicity and mutagenicity induced by cyclophosphamide in male Swiss mice Melo-Cavalcante et al.
DNA damage protective effect of honey-sweetened cashew apple nectar in Drosophila melanogaster
The juice exerted antigenotoxic effects, decreasing the frequency of cyclophosphamide-induced micronucleus and DNA damage in peripheral blood of mice, and of chromosome aberrations in bone marrow. Considering the high ascorbic acid concentrations found in cashew apple pulp and HSCAN, the observed antimutagenic and co-mutagenic effects might be a result of this vitamin’s action. Ascorbic acid was effective in reducing the genotoxicity of K 2 Cr 2 O 7but not of ktltsi, at the same time that it caused significant increase in mutant clones when combined with CoCl 2.
In another investigation, the modulatory effect tmuyat ascorbic acid on the mutagenic activity of doxorubicin DXR was evaluated using the same assay, in both ST and high-bioactivation Hmutat crosses Fragiorge et al. On the contrary, an increased frequency of spots induced by DXR was observed with the highest concentration tested mM.
The authors suggested that ascorbic acid may interfere with DXR generated free radicals and with kit,tsi possible reactive metabolites. This vitamin was also effective in reducing the incidence of micronucleus in human lymphocytes in vitro in the DXR co-treatment, but not in pre- and post-treatments Amara-Mokrane et al. Also on lymphocytes, cisplatin-induced clastogenesis was reduced by ascorbic acid in a co-treatment protocol Lee, Additionally, ascorbic acid also reduced chromosome aberrations induced by rifampicin, an antituberculosis agent, when mice were co-treated with both compounds.
Repeated doses of vitamin C reduced the percentage of rifampicin-induced DNA damage in a significant and dose-dependent manner Aly and Donya, Similarly, aqueous extracts of rose petals from different cultivars exhibited antimutagenicity against EMS-induced mutagenesis using the Escherichia coli RNA polymerase B forward mutation assay. The bioactive compound purified from the most potent rose cultivar was identified as an anthocyanin, which have potential health benefits Kumar et al.
Among carotenoids, beta-carotene showed antigenotoxic properties in relation to radioactive iodine and doxorubicin in Wistar rats using chromosomal aberration Berti et al.
The results indicated that 5-caffeoylquinic acid standard was highly effective in the inhibition of 4-nitro-o-phenylene-diamine NPD and 2-aminofluorene 2-AF mutagens, mainly due to caffeic acid, which had similar antimutagenic activity. Although honey has not been tested against EMS in the present study, it showed protective and co-mutagenic activity in co- and post-treatments, respectively, on MMC-induced DNA lesions.
Previous chemical analysis of this honey sample by our research group, showed a total phenolic content of Studies of the antimutagenic activity of honey are very scarce. The different effects of honey against induced mutagenesis could probably be due to differences in the samples’ phenol and protein content Saxena et al. However, some authors found that sugars in kitltssi contributed significantly to the antimutagenicity of this compound, and that monosaccharides were more potent antimutagens than disaccharides Wang et al.
Considering that the compounds tested in the present study are complex mixtures kitltis bioactive components, the different antimutagenic responses found seem plausible.
Although MMC causes mainly DNA inter- and intrastrand cross-links and bulky 0 6 -guanine monoadducts, the protective effect against MMC may be associated with the antioxidant activity of compounds, as MMC is also able to generate free radicals Turkez et al.
On the other hand, the preventive effect against EMS mutagenesis cannot be related to antioxidant activity, since EMS is an alkylating agent and a direct-acting mutagen. The protective action, therefore, oitltsi possibly mediated by the reaction of the tested compounds with reactive chemicals and trapping of the ethyl radical. The direct mispairing, caused by the addition of an EMS ethyl group to the O 6 position of guanine and the O 4 position of thymine in the DNA, could be scavenged by the reaction with some bioactive components of the honey, cashew apple pulp and HSCAN Guerrini et al.
Briefly, the data presented in this study show that HSCAN was able to reduce the mutagenic activity of EMS and MMC, when co-administered with these genotoxins, at the same time that it increased the frequency of mutagenic lesions when post-administered.
The same behavior was observed for honey in relation to MMC genotoxicity. Cashew apple pulp presented different results only in the post-treatment protocol, in which protective and inducing activities were observed, depending on the applied concentration. In this sense, some studies have reported that bioactive components of fruits and vegetables can interfere with the expression of DNA repair enzymes Ferguson et al.
Considering previously published data, a definitive conclusion about the protective effects of cashew apple pulp, honey and related beverages against chemical and physical DNA injuries cannot be drawn.
Further studies with the Drosophila SMART assay and other bioassays should be performed to better understand the mechanisms and conditions underlying the chemopreventive and co-mutagenic activities of these compounds.
Abraham SK Antigenotoxicity of coffee in the Drosophila assay for somatic mutation and recombination. Role of bioactivation capacity. Food Chem Toxicol Evaluation of their genotoxic and antigenotoxic effects.
Possible influence of DPPH free radical scavengers. Afr J Biotechnol Akinwale TO Cashew apple juice: Its use in fortifying the nutritional quality of some tropical fruits. Eur Food Res Technol Food Sci Biotechnol Correlation with their antigenotoxic and antioxidant properties.
Genet Mol Res Asian Pac J Trop Dis Environ Mol Mutagen Antigenotoxic activity of berries.