Cancer Prevention and Health Benefices of Traditionally Consumed Borago officinalis Plants.

Nowadays, healthy eating is increasing the demand of functional foods by societies as sources of bioactive products with healthy qualities. For this reason, we tested the safety of the consumption of Borago officinalis L. and its main phenolic components as well as the possibility of its use as a nutraceutical plant to help in cancer prevention. The in vivo Drosophila Somatic Mutation and Recombination Test (SMART) and in vitro HL-60 human cell systems were performed, as well-recognized methods for testing genotoxicity/cytotoxicity of bioactive compounds and plant products. B. officinalis and the tested compounds possess antigenotoxic activity. Moreover, B. officinalis wild type cultivar exerts the most antigenotoxic values. Cytotoxic effect was probed for both cultivars with IC50 values of 0.49 and 0.28 mg · mL(-1) for wild type and cultivated plants respectively, as well as their constituent rosmarinic acid and the assayed phenolic mixture (IC50 = 0.07 and 0.04 mM respectively). B. officinalis exerts DNA protection and anticarcinogenic effects as do its component rosmarinic acid and the mixture of the main phenolics presented in the plant. In conclusion, the results showed that B. officinalis may represent a high value plant for pleiotropic uses and support its consumption as a nutraceutical plant.

Antigenotoxicity and Tumor Growing Inhibition by Leafy Brassica carinata and Sinigrin.

Cruciferous vegetables are well known and worldwide consumed due to their health benefits and cancer prevention properties. As a desirable cruciferous plant, Ethiopian mustard (Brassica carinata A. Braun) and its glucosinolate sinigrin were tested in the in vivo Drosophila melanogaster (SMART) and the in vitro HL60 (human promyelocytic leukaemia cell line) systems. High performance liquid chromatography (HPLC) analysis of plant samples confirmed the presence of sinigrin as principal B. carinata glucosinolate. SMART was performed by feeding D. melanogaster larvae either with different concentrations of plant/compound samples or combining them with hydrogen peroxide (a potent oxidative mutagen) being both antimutagenics. HL60 assays showed the tumoricidal activity of plant samples (IC50 = 0.28 mg·mL(-1)) and the breakdown products of sinigrin hydrolysis (IC50 = 2.71 µM). Our results enhance the potential of B. carinata as health promoter and chemopreventive in both systems and the leading role of sinigrin in these effects.

Evaluation of potential antigenotoxic, cytotoxic and proapoptotic effects of the olive oil by-product "alperujo", hydroxytyrosol, tyrosol and verbascoside.

Olive oil is an integral ingredient of the "Mediterranean diet". The olive oil industry generates large quantities of a by-product called "alperujo" (AL) during the two-phase centrifugation system developed in the early nineties. AL could be a potent exploitable source of natural phenolic antioxidants. Our results showed that AL and its distinctive phenols hydroxytyrosol, tyrosol and verbascoside were not genotoxic in the Somatic Mutation and Recombination Test (SMART) of Drosophila melanogaster and exerted antigenotoxic activity against DNA oxidative damage generated by hydrogen peroxide (H2O2). Alperujo and hydroxytyrosol also exhibited notable antiproliferative and caspase 3-dependent proapoptotic effects toward the human tumoral cell line HL60. AL can provide a cheap and efficient source of chemopreventive phenolic compounds with strong antioxidant properties, becoming a promising and potent therapeutic drug in the future.

Cytotoxic and genotoxic effects of metal(oid)s bioactivated in rocket leaves (Eruca vesicaria subsp. sativa Miller).

Rocket is an important source of essential elements. However, it may also accumulate toxic elements such as metal(oids). The objectives of the present work were (i) to study the uptake of arsenic, lead, cadmium and zinc in rocket grown in contaminated soils, (ii) to establish the genotoxic and cytotoxic activities of this vegetable material, and (iii) to study the modulator role of the glucosinolate and metal contents in the genotoxic/cytotoxic activities. Lead, cadmium and zinc leaf concentrations in our study were over the concentrations allowed by the statutory limit set for metal(oid) contents in vegetables. The accessions were non genotoxic at the different concentrations studied, although one of the accessions showed the highest mutation rates doubling those of negative control. The cytotoxicity assays with HL60 human leukaemia cells showed that the tumouricide activities of rocket leaves decreased with the increasing of metal(oid) concentrations and also with the decreasing of glucosinolate concentrations in their tissues. An interaction between metal(oid)s and glucosinolate degradation products contained in rocket leaves is suggested as the main modulator agents of the biological activity of the plants grown in metal-contaminated soils.

Protective effect of borage seed oil and gamma linolenic acid on DNA: in vivo and in vitro studies.

Borage (Borago officinalis L.) seed oil has been used as a treatment for various degenerative diseases. Many useful properties of this oil are attributed to its high gamma linolenic acid content (GLA, 18:3 ω-6). The purpose of this study was to demonstrate the safety and suitability of the use of borage seed oil, along with one of its active components, GLA, with respect to DNA integrity, and to establish possible in vivo toxic and in vitro cytotoxic effects. In order to measure these properties, five types of assays were carried out: toxicity, genotoxicity, antigenotoxicity, cytotoxicity (using the promyelocytic leukaemia HL60 cell line), and life span (in vivo analysis using the Drosophila model). Results showed that i) Borage seed oil is not toxic to D. melanogaster at physiological concentrations below 125 µl/ml and the studies on GLA indicated non-toxicity at the lowest concentration analyzed ii) Borage seed oil and GLA are DNA safe (non-genotoxic) and antimutagenic compared to hydrogen peroxide, thereby confirming its antioxidant capacity; iii) Borage seed oil and GLA exhibited cytotoxic activity in low doses (IC50 of 1 µl/ml and 0.087 mM, respectively) iv) Low doses of borage seed oil (0.19%) increased the health span of D. melanogaster; and v) GLA significantly decreased the life span of D. melanogaster.Based on the antimutagenic and cytotoxic effects along with the ability to increase the health span, we propose supplementation with borage seed oil rather than GLA, because it protects DNA by modulating oxidative genetic damage in D. melanogaster, increases the health span and exerts cytotoxic activity towards promyelocytic HL60 cells.

Characterization and prediction by near-infrared reflectance of mineral composition of rocket (Eruca vesicaria subsp. sativa and Eruca vesicaria subsp. vesicaria).

BACKGROUND: Minerals are essential for human nutrition and must be obtained from our diet. Crucifer vegetables are a good source of these nutrients. Our objectives were to determine the genetic variability for mineral content and to evaluate the use of near-infrared reflectance spectroscopy (NIRS) for prediction of ashes and minerals among and within the rocket species Eruca vesicaria subsp. sativa and vesicaria. The minerals studied were iron (Fe), copper (Cu), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn) and zinc (Zn). RESULTS: The maximum mean values obtained for all the accessions (mean ± SE) were 235.5 ± 1.5 mg ashes kg(-1), 273.3 ± 4.2 mg Fe kg(-1), 18.1 ± 0.4 mg Cu kg(-1), 2.8 ± 0.1 g Na kg(-1), 71.6 ± 1.0 g K kg(-1), 64.6 ± 1.2 g Ca kg(-1), 6.8 ± 0.1 g mg kg(-1), 101.6 ± 1.2 mg Mn kg(-1), and 67.1 ± 0.4 mg Zn kg(-1) of dry weight. CONCLUSION: The statistical analysis showed significant differences for all the minerals, except Ca, for each accession studied individually and for accessions grouped within countries. The results indicate that NIRS can be used as a rapid screening method for determining total mineral, Fe, Na, K, and Zn in rocket.

The effect of the Spanish Ketogenic Mediterranean Diet on nonalcoholic fatty liver disease: a pilot study.

The "Spanish Ketogenic Mediterranean Diet" (SKMD) has been shown to be an effective and safe way to cure patients suffering from metabolic syndrome (MS). Keeping in mind that nonalcoholic fatty liver disease (NAFLD) is closely associated with MS, the purpose of this study was to evaluate the potential therapeutic properties under free living conditions of the SKMD in patients with MS (following the International Diabetes Federation [IDF] consensus guidelines) and NAFLD (suspected by using a cutoff value of alanine aminotransferase [ALT] levels of >40 U/L and confirmed by abdominal ultrasonography) over a 12-week period. A prospective study was carried out in 14 obese men meeting the inclusion criteria and whose body mass index (BMI) and age were 36.58±0.54 kg/m² and 41.18±2.28 years, respectively. Statistical differences between the parameters studied before and after administration of the SKMD (week 0 and 12) were analyzed by paired Student's t test (continuous variables) and the χ² test (discontinuous variables). P<.05 was considered statistically significant. There was an extremely significant (P<.001) improvement in body weight (from 109.79 kg to 95.86 kg), low-density lipoprotein-cholesterol (from 123.43 mg/dL to 100.35 mg/dL), ALT (from 71.92 U/L to 37.07 U/L), aspartate aminotransferase (from 47.71 U/L to 29.57 U/L), steatosis degree (complete fatty liver regression was observed in 21.4% of the patients, and an overall reduction was found in 92.86% of the patients), and all the parameters studied associated with the MS: BMI (from 36.99 kg/m² to 32.42 kg/m²), waist circumference (from 114.01 cm to 98.59 cm), fasting plasma glucose (from 118.57 mg/dL to 90.14 mg/dL), triacylglycerols (from 232.64 mg/dL to 111.21 mg/dL), high-density lipoprotein-cholesterol (HDLc) (from 42.81 mg/dL to 58.71 mg/dL), systolic blood pressure (from 142.86 mm Hg to 125.36 mm Hg), and diastolic blood pressure (from 89.64 mm Hg to 77.86 mm Hg). After the diet all the subjects were free of MS according to the IDF definition, and 100% of them had normal triacylglycerols and HDLc levels, in spite of the fact that 100% of them still had a BMI of >30 kg/m². We conclude that the SKMD could be an effective and safe way to treat patients suffering from MS and the associated NAFLD.

Role of citrus juices and distinctive components in the modulation of degenerative processes: genotoxicity, antigenotoxicity, cytotoxicity, and longevity in Drosophila.

It is well established that breakfast beverages contain high quantities of Citrus juices. The purpose of the present study was to assess the nutraceutical value of orange and lemon juices as well as two of their active compounds: hesperidin and limonene. Indicator assays were performed at three levels to evaluate different biological health promoter activities: (i) determination of the safety and DNA-damage protecting ability against free radicals by using the somatic mutation and recombination test (SMART) in Drosophila melanogaster, (ii) study of the modulating role for life span in Drosophila melanogaster, and (iii) measurement of the cytotoxic activity against the human tumor cell line HL60. The highest concentrations assayed for lemon juice and limonene (50% v/v and 0.73 mM, respectively) showed genotoxic activity as evidenced from SMART. Orange and lemon juices as well as hesperidin and limonene exhibit antigenotoxic activity against hydrogen peroxide used as an oxidative genotoxin. Life-span experiments revealed that the lower concentrations of orange juice, hesperidin, and limonene exerted a positive influence on the life span of Drosophila. Finally all substances showed cytotoxic activity, with hesperidin being least active. Taking into account the safety, antigenotoxicity, longevity, and cytotoxicity data obtained in the different assays, orange juice may be a candidate as a nutraceutical food as it (1) is not genotoxic, (2) is able to protect DNA against free radicals, and (3) inhibits growth of tumor cells.

A pilot study of the Spanish Ketogenic Mediterranean Diet: an effective therapy for the metabolic syndrome.

The "Spanish Ketogenic Mediterranean Diet" (SKMD) has been shown to promote potential therapeutic properties for the metabolic syndrome. The purpose of this study was to evaluate the potential therapeutic properties under free-living conditions of the SKMD in patients with metabolic syndrome (following the International Diabetes Federation consensus guidelines) over a 12-week period. A prospective study was carried out in 22 obese subjects with metabolic syndrome (12 men and 10 women) with the inclusion criteria whose body mass index of 36.58 ± 0.54 kg/m² and age was 41.18 ± 2.28 years. Statistical differences between the parameters studied before and after the administration of the SKMD (week 0 and 12, respectively) were analyzed by paired Student's t test. There was an extremely significant (P < .001) improvement in low-density lipoprotein cholesterol (from 126.25 mg/dL to 103.87 mg/dL) and all the parameters studied associated with metabolic syndrome: body weight (from 106.41 kg to 91.95 kg), body mass index (from 36.58 kg/m² to 31.69 kg/m²), waist circumference (from 111.97 cm to 94.70 cm), fasting plasma glucose (from 118.81 mg/dL to 91.86 mg/dL), triacylglycerols (from 224.86 mg/dL to 109.59 mg/dL), high-density lipoprotein cholesterol (from 44.44 to 57.95 mg/dL), systolic blood pressure (from 141.59 mm Hg to 123.64 mm Hg), and diastolic blood pressure (from 89.09 mm Hg to 76.36 mm Hg). The most affected parameter was the triacylglycerols (51.26% reduction). After the diet all the subjects were free of metabolic syndrome according to the International Diabetes Federation definition, and 100% of them had normal triacylglycerols and high-density lipoprotein cholesterol levels, in spite of the fact that 77.27% of them still had a body mass index of > 30 kg/m². We conclude that the SKMD could be an effective and safe way to cure patients suffering from metabolic syndrome. Future research should include a larger sample size, a longer-term use, and a comparison with other ketogenic diets.

A pilot study on the DNA-protective, cytotoxic, and apoptosis-inducing properties of olive-leaf extracts.

Leaves of olive trees are an abundant raw material in the Mediterranean basin. They contain large amounts of potentially useful phytochemicals and could play beneficial roles in health care. In the present study, the principal bioactive phenols in olive-leaf extracts (OLEs) have been identified and quantified, and their genotoxic/antigenotoxic, cytotoxic and apoptotic effects have been assessed. The Somatic Mutation and Recombination Test (SMART) in wing imaginal discs of Drosophila melanogaster has been performed to test the possible genotoxicity of overall OLE and the individual components oleuropein and luteolin at different concentrations. The same assay was able to detect antigenotoxic activity against hydrogen peroxide as oxidative genotoxicant. None of the extracts/phenols tested showed significant mutagenic activity. This fact, together with the antigenotoxic activity against H(2)O(2) detected for all these extracts/phenols, confirmed the safety of OLE, oleuropein and luteolin in terms of DNA protection. HL60 human promyelocytic leukemia cells were used to assess the cytotoxic effects of the extracts/phenols. OLE, oleuropein and luteolin showed a dose-dependent cytotoxic effect with different IC50 (10µl/ml, 170µM, and 40µM, respectively). DNA fragmentation patterns and cell staining with acridine orange and ethidium bromide indicated that the mechanism for the cytotoxic effect of OLE, oleuropein and luteolin was the apoptotic pathway, with DNA laddering and cytoplasmic and nuclear changes. These results could help explain the mechanism of action that underlies the beneficial effect of OLE, proposed as a nutraceutical in the prevention of human cancer.

Targets of red grapes: oxidative damage of DNA and leukaemia cells.

Vitis vinifera is a widespread crop all over the world. The biophenols present in grapes have a remarkable influence on wine quality and also confer potential health-protecting properties to this fruit. The aim of the present work was to assess the beneficial properties of skin, seeds and pulp of red table grapes (RTG) (Vitis vinifera, Palieri Cadiz variety). Two potential beneficial activities of red table grapes (RTG) were analyzed: (i) The maintenance of genomic stability studying their genotoxic/antigenotoxic effects, and (ii) the in vitro cytotoxic effect against tumor cells of RTG components. The genotoxic and/or antigenotoxic effect was measured applying the somatic mutation and recombination test on wing imaginal discs of Drosophila melanogaster. The cytotoxic effect was monitored using the HL60 human leukemia model to evaluate the antiproliferative potential of the different parts of RTG. The three major parts (skin, seeds and pulp) are not genotoxic. When antigenotoxicity assays were performed using hydrogen peroxide as the oxidative genotoxin, skin, seed and pulp exerted a desmutagenic effect, with seeds and skin showing the most potent effect. The cytotoxicity tests using HL60 cells indicated that only skin and pulp fractions are able to inhibit the tumor growth, with skin having the lowest IC50 (1.8 mg/mL versus 8 mg/mL of pulp). These results suggest that RTG are potent anti-mutagens that protect DNA from oxidative damage as well as being cytotoxic toward the HL60 tumor cell line.

Antigenotoxicity, cytotoxicity, and apoptosis induction by apigenin, bisabolol, and protocatechuic acid.

Medicinal plants represent an important resource in new drug research. Antioxidant properties of plants can help to scavenge reactive oxygen species. The objective of this work was to evaluate the genotoxic, antigenotoxic, tumoricidal, and apoptotic effect of some major phenols (apigenin, bisabolol, and protocatechuic acid) from two medicinal plants, Matricaria chamomilla and Uncaria tomentosa. The wing spot test of Drosophila melanogaster was used to evaluate the genotoxicity and antigenotoxicity of the three phenols. The human model of HL-60 leukemia cells was used for the assessment of the cytotoxic effect, growth, and cellular viability. The apoptotic effect was evaluated using a DNA fragmentation assay based on the formation of internucleosomal units. Protocatechuic acid (0.25 and 1 mM), apigenin (0.46 and 1.85 mM), and bisabolol (0.56 and 2.24 mM) did not exhibit any genotoxic effect. The three phenols showed an antigenotoxic effect against the hydrogen peroxide effect and also exhibited tumoricidal activity. Apigenin (2.24-35.96 mM) showed a lower 50% inhibitory concentration (0.75 and 3.87 mM for the trypan blue test and WST-8 colorimetric assay, respectively) than bisabolol and protocatechuic acid. These phenolics also induced apoptosis in HL-60 leukemia cells. This study suggests that the antioxidant activity of Chamomilla and Uncaria could be partially responsible of their beneficial activity.

Modulation of genotoxicity by extra-virgin olive oil and some of its distinctive components assessed by use of the Drosophila wing-spot test.

Olive oil is an important source of mono-unsaturated fat and a prime component of the Mediterranean diet. The beneficial health effects of olive oil are due to both its high content of mono-unsaturated fatty acids and its high content of anti-oxidative substances. The objective of this study was to investigate the basis for the epidemiological information relating to the health benefits associated with the consumption of extra-virgin olive oil (EVOO). For this purpose, the somatic mutation and recombination test (SMART) in wings of Drosophila melanogaster was applied to evaluate the antigenotoxic activity of six different EVOOs from four Spanish varieties (Hojiblanca, Nevadillo, Casta de Cabra, Picual). A two-level approach was followed: (1) determination of the lack of genotoxicity along with the antigenotoxic activity of EVOOs, through antigenotoxicity assays, with hydrogen peroxide as an oxidative genotoxin, and (2) evaluation of the properties of three major distinctive components of EVOOs that could be responsible for their antigenotoxic activity. The EVOOs tested are shown to be non-genotoxic; they exhibited antigenotoxic activity against the effects of hydrogen peroxide. Triolein, tyrosol and squalene did not show genotoxic effects in the proliferative imaginal cells of D. melanogaster. The three components were antigenotoxic when combined with soybean oil, only triolein and tyrosol showed a clear desmutagenic effect when combined with hydrogen peroxide. Our results confirm the safety of EVOOs and their health-protective effects.

Antisense down-regulation of the FaPG1 gene reveals an unexpected central role for polygalacturonase in strawberry fruit softening.

The strawberry (Fragaria x ananassa 'Chandler') fruit undergoes a fast softening during ripening. Polygalacturonase (PG) activity is low during this process, but two ripening-related PG genes, FaPG1 and FaPG2, have been cloned. Both genes were up-regulated during fruit ripening and were also negatively regulated by auxin. To further assess the role of FaPG1 on strawberry softening, transgenic plants containing an antisense sequence of this gene under the control of the 35S promoter (APG lines) were obtained. Sixteen out of 30 independent transgenic lines showed fruit yields similar to those of the control. Several quality parameters were measured in ripe fruits from these 16 lines. Fruit weight was slightly reduced in four lines, and most of them showed an increase in soluble solid content. Half of these lines yielded fruits significantly firmer than did the control. Four APG lines were selected, their ripened fruits being on average 163% firmer than the control. The postharvest softening of APG fruits was also diminished. Ripened fruits from the four selected lines showed a 90% to 95% decrease in FaPG1 transcript abundance, whereas the level of FaPG2 was not significantly altered. Total PG activity was reduced in three of these lines when compared with control fruits. Cell wall extracts from APG fruits showed a reduction in pectin solubilization and an increase in pectins covalently bound to the cell wall. A comparative transcriptomic analysis of gene expression between the ripened receptacle of the control and those of the APG fruits (comprising 1,250 receptacle expressed sequence tags) did not show any statistically significant change. These results indicate that FaPG1 plays a central role in strawberry softening.

Multivariate discriminant analysis distinguishes metal- from non metal-related biomarker responses in the clam Chamaelea gallina.

Molecular biomarkers are among the most sensitive and earliest responses to pollutants. However, lack of detailed knowledge on variability of responses and their possible seasonal variation limit their use. In addition, the seasonality of biological processes modulates the response of organisms to pollutant stressors. Using multivariate statistics, we have studied the influence of environmental and biological factors on the response of a battery of molecular biomarkers in the clam Chamaelea gallina collected along the South-Spanish littoral. Multivariate discriminant analysis clearly distinguished biomarker response between clean and polluted areas, using heavy metals as indicator of pollution. Such differences disappeared when the dataset was normalised for metal content, thus indicating that pollution was the main significant cause of the changes observed between clean and polluted sites. In conclusion, this work shows that, when applying a complete biomarker panel, multivariate statistical tools can be used to discern pollutant- from non pollutant-related responses.

Spanish Ketogenic Mediterranean Diet: a healthy cardiovascular diet for weight loss.

BACKGROUND: Ketogenic diets are an effective healthy way of losing weight since they promote a non-atherogenic lipid profile, lower blood pressure and decrease resistance to insulin with an improvement in blood levels of glucose and insulin. On the other hand, Mediterranean diet is well known to be one of the healthiest diets, being the basic ingredients of such diet the olive oil, red wine and vegetables. In Spain the fish is an important component of such diet. The objective of this study was to determine the dietary effects of a protein ketogenic diet rich in olive oil, salad, fish and red wine. METHODS: A prospective study was carried out in 31 obese subjects (22 male and 19 female) with the inclusion criteria whose body mass index and age was 36.46 +/- 2.22 and 38.48 +/- 2.27, respectively. This Ketogenic diet was called "Spanish Ketogenic Mediterranean Diet" (SKMD) due to the incorporation of virgin olive oil as the principal source of fat (> or =30 ml/day), moderate red wine intake (200-400 ml/day), green vegetables and salads as the main source of carbohydrates and fish as the main source of proteins. It was an unlimited calorie diet. Statistical differences between the parameters studied before and after the administration of the "Spanish Ketogenic Mediterranean diet" (week 0 and 12) were analyzed by paired Student's t test. RESULTS: There was an extremely significant (p < 0.0001) reduction in body weight (108.62 kg--> 94.48 kg), body mass index (36.46 kg/m(2)-->31.76 kg/m(2), systolic blood pressure (125.71 mmHg-->109.05 mmHg), diastolic blood pressure (84.52 mmHg--> 75.24 mmHg), total cholesterol (208.24 mg/dl-->186.62 mg/dl), triacylglicerols (218.67 mg/dl-->113.90 mg/dl) and glucose (109.81 mg/dl--> 93.33 mg/dl). There was a significant (p = 0.0167) reduction in LDLc (114.52 mg/dl-->105.95 mg/dl) and an extremely significant increase in HDLc (50.10 mg/dl-->54.57 mg/dl). The most affected parameter was the triacylglicerols (47.91% of reduction). CONCLUSION: The SKMD is safe, an effective way of losing weight, promoting non-atherogenic lipid profiles, lowering blood pressure and improving fasting blood glucose levels. Future research should include a larger sample size, a longer term use and a comparison with other ketogenic diets.

Evaluation of the Campbell test and the influence of age, sex, breed, and coat color on puppy behavioral responses.

The aim of this study was to evaluate the Campbell test and discover if there is a link between a puppy's scores and factors such as age, breed, sex, sex-breed interaction, size, Fédération Cynologique Internationale (FCI) groups, and coat color. The Campbell test was performed on 342 puppies (191 males and 151 females) of different breeds. The results show that the criteria used by Campbell to classify puppies are incomplete, and that it is more appropriate to use numerical values for each type of answer. In general, the mean value obtained, regardless of sex and breed, corresponded to the Campbell's submissive stable category. The mean value was higher in male dogs than in females.

Two translesion synthesis DNA polymerase genes, AtPOLH and AtREV1, are involved in development and UV light resistance in Arabidopsis.

Plants are continually exposed to external and internal DNA-damaging agents. Although lesions can be removed by different repair processes, damages often remain in the DNA during replication. Synthesis of template damages requires the replacement of replicative enzymes by translesion synthesis polymerases, which are able to perform DNA synthesis opposite specific lesions. These proteins, in contrast to replicative polymerases, operate at low processivity and fidelity. DNA polymerase eta and Rev 1 are two proteins found in eukaryotes that are involved in translesion DNA synthesis. In Arabidopsis, DNA polymerase eta and Rev 1 are encoded by AtPOLH and AtREV1 genes, respectively. Transgenic plants over-expressing AtPOLH showed increased resistance to ultraviolet light. Only plants with moderate AtREV1 over-expression were obtained, indicating that this enzyme could be toxic at high levels. Transgenic plants that over-expressed or disrupted AtREV1 showed reduced germination percentage, but the former exhibited a higher stem growth rate than the wild type during development.

Genotoxicity and anti-genotoxicity of some traditional medicinal herbs.

Six herbal infusions used worldwide (Matricaria chamomilla, Tilia cordata, Mentha piperita, Mentha pulegium, Uncaria tomentosa and Valeriana officinalis) were assayed for anti-genotoxicity using the Somatic Mutation And Recombination Test (SMART) in Drosophila melanogaster. All these infusions are traditionally used for various medical purposes, including anti-inflammatory processes. Hydrogen peroxide was used as an oxidative genotoxicant to test the anti-genotoxic potency of the medicinal infusions. None of these infusions showed a significant genotoxicity, quite the reverse they were able to behave as desmutagens, detoxifying the mutagen hydrogen peroxide. The phenolic content of such herbal infusions is argued to be the possible scavenger of reactive oxygen radicals produced by the hydrogen peroxide.

Genotoxicity of vegetable cooking oils in the Drosophila wing spot test.

Seven vegetable oils consumed by humans were tested for genotoxic activity in the Drosophila somatic mutation and recombination test. The oils included five seed oils (sesame, sunflower, wheat germ, flax, and soy oil) and both first-class extra-virgin and low-grade (refined) olive oil. Larvae of the standard (STD) and highly bioactive (NORR) crosses of Drosophila melanogaster were fed medium containing 6% and 12% of each of the oils. Flax oil produced the strongest response, while sesame, wheat germ, and soy oil showed some genotoxic activity. Sunflower and the low-grade olive oil gave inconclusive results, and extra-virgin olive oil was clearly nongenotoxic. It is argued that the genotoxicity is probably due to the fatty acid composition of the oils, which after peroxidation can form specific DNA-adducts.