Glucosinolates, Ca, Se Contents, and Bioaccessibility in Brassica rapa Vegetables Obtained by Organic and Conventional Cropping Systems.

In northwest Spain and Portugal, there is a long tradition of cultivating B. rapa subsp. rapa to obtain turnip greens and turnip tops. Brassica rapa L. subsp. rapa (turnip greens and turnip tops) were grown under conventional and organic conditions in two Farms in southern Spain. Glucosinolatescontents were higher in Brassicas grown under conventional conditions than those grown under organic ones. Average Ca total and bioaccessible contents ranged between 14.6-23.4 mg/g; 8.9-12.0 mg/g for turnip greens and 6.4-8.9 mg/g; 4.3-4.8 mg/g for turnip tops. According to these concentrations, an intake of 100-200 g (fresh weight) of the studied Brassica rapa fulfills Ca dietary reference intakes (DRI) (considering the total content data) and complies with 72-100% Ca DRI percentage (considering the bioaccessible data). Se concentrations ranged between 0.061-0.073 µg/g and 0.039-0.053 µg/g for turnip greens and turnip tops respectively. Se bioaccessibility values were high, with percentages of around 90%. Finally, the total glucosinolate content ranged between 13.23-21.28 µmol/g for turnip greens and 13.36-20.20 µmol/g for turnip tops. In general, the bioaccessibility of the total glucosinolates analyzed in this study was high, with mean values of around 73% and 66% for turnip greens and turnip tops, respectively. Brassica rapa vegetables grown under both organic and conventional conditions in southern Spain are an excellent dietary source of Ca, Se, and glucosinolates with a high bioaccessibility.

Role of Glucosinolates in the Nutraceutical Potential of Selected Cultivars of Brassica rapa.

Brassica rapa L. subsp. rapa (turnip greens), a traditionally consumed vegetable, is well-known due to its high content of glucosinolates, which are secondary metabolites with a positive biological activity for human health. Our hypothesis has been based on the relation between B. rapa glucosinolate content and its healthy properties, and our aim is to establish guidelines for safe B. rapa vegetable consumption. Three B. rapa cultivars (143N5, 143N7 and 163N7) have been characterized by HPLC analysis of purified extracts from leaf samples in order to determine their glucosinolate content and to relate this content to beneficial effects on DNA protection, lifespan extension and chemoprevention. In order to ascertain the heath properties in vitro and in vivo, toxicity activities were assayed in the Drosophila melanogaster and leukaemia cell models; genomic safety was also assessed in both models using genotoxicity, fragmentation and comet assay. The Drosophila model has also been used to study the antioxidative activity and the longevity induction. Our results showed a relationship between B. rapa glucosinolate content and its safety and benefices in its consumption. Gluconapin, the main B. rapa glucosinolate, was directly related with these wholesome effects. The relevant conclusion in the present research is focused on B. rapa cultivar 163N7 due to its high gluconapin content and low progoitrin content, which exert anti-cancer and DNA protection properties and could be recommended as being safe and healthy for human consumption.

Health-Promoting Properties of Borage Seed Oil Fractionated by Supercritical Carbon Dioxide Extraction.

Borage (Borago officinalis L.) seed oil is an important source of γ-linolenic acid, which is normally used as a treatment against different pathologies. Since the fractionation of this interesting seed oil has many environmental, economic and biological benefits, two borage fractionation techniques after extraction with CO2 under supercritical conditions have been studied: precipitation in two cyclone separators and countercurrent extraction column. Both techniques have successfully collected free fatty acids in one fraction: (i) two separators set up in series obtained the highest concentration of free fatty acids in separator 2 at 90 bar/40 °C; (ii) when countercurrent extraction column was used, the acidity index of the raffinate stream was independent from the operating conditions (2.6 ± 0.5%). Furthermore, the composition of the fatty acids, as well as their antioxidant and cytotoxic activities, were determined. The profile of the fatty acids obtained by either of these two methods remained unaltered, so that the crude oil exhibited improved antioxidant and cytotoxic properties. All the extracts obtained in the two cyclone separators at the same pressure/temperature conditions displayed high tumouricidal activity against HL 60 promyelocytic leukaemia cells, even if the extracts at 50% concentration from separator 2 presented a lower inhibitory activity (IC50). The extracts from separator 2 at 90 bar/40 °C exhibited the highest anti-proliferative activity at low doses (IC50 of 0.3 µL/mL for the trypan blue exclusion test). To reach the lethal dose-IC50-with the product obtained through countercurrent column fractionation, a concentration of 2 µL/mL of crude borage oil raffinate was required.

Analysis of the Acid Detergent Fibre Content in Turnip Greens and Turnip Tops (Brassica rapa L. Subsp. rapa) by Means of Near-Infrared Reflectance.

Standard wet chemistry analytical techniques currently used to determine plant fibre constituents are costly, time-consuming and destructive. In this paper the potential of near-infrared reflectance spectroscopy (NIRS) to analyse the contents of acid detergent fibre (ADF) in turnip greens and turnip tops has been assessed. Three calibration equations were developed: in the equation without mathematical treatment the coefficient of determination (R2) was 0.91, in the first-derivative treatment equation R2 = 0.95 and in the second-derivative treatment R2 = 0.96. The estimation accuracy was based on RPD (the ratio between the standard deviation and the standard error of validation) and RER (the ratio between the range of ADF of the validation as a whole and the standard error of prediction) of the external validation. RPD and RER values were of 2.75 and 9.00 for the treatment without derivative, 3.41 and 11.79 with first-derivative, and 3.10 and 11.03 with second-derivative. With the acid detergent residue spectrum the wavelengths were identified and associated with the ADF contained in the sample. The results showed a great potential of NIRS for predicting ADF content in turnip greens and turnip tops.

Seed Oil Quality of Brassica napus and Brassica rapa Germplasm from Northwestern Spain.

The seed oil content and the fatty acid composition of a germplasm collection of Brassica napus and Brassica rapa currently grown in Galicia (northwestern Spain) were evaluated in order to identify potentially interesting genotypes and to assess their suitability as oilseed crops for either edible or industrial purposes. The seeds of the B. rapa landraces had higher oil content (mean 47.3%) than those of B. napus (mean 42.8%). The landraces of both species showed a similar fatty acid profile (12% oleic acid, 13% linoleic acid, 8-9% linolenic acid, 8-9% eicosenoic acid, and 50-51% erucic acid). They were very high in erucic acid content, which is nutritionally undesirable in a vegetable oil, and very low in oleic and linoleic acid contents. Therefore, they could be used for industrial purposes but not as edible oil. The erucic acid content ranged from 42% to 54% of the total fatty acid composition with an average value of 50% in the B. napus landraces whereas in B. rapa, it ranged from 43% to 57%, with an average value of 51%. Considering the seed oil and the erucic acid content together, three varieties within the B. napus collection and two varieties within the B. rapa one seem to be the most promising genotypes for industrial purposes.

Rapid and Cost-Effective Quantification of Glucosinolates and Total Phenolic Content in Rocket Leaves by Visible/Near-Infrared Spectroscopy.

The potential of visible-near infrared spectroscopy to predict glucosinolates and total phenolic content in rocket (Eruca vesicaria) leaves has been evaluated. Accessions of the E. vesicaria species were scanned by NIRS as ground leaf, and their reference values regressed against different spectral transformations by modified partial least squares (MPLS) regression. The coefficients of determination in the external validation (R²VAL) for the different quality components analyzed in rocket ranged from 0.59 to 0.84, which characterize those equations as having from good to excellent quantitative information. These results show that the total glucosinolates, glucosativin and glucoerucin equations obtained, can be used to identify those samples with low and high contents. The glucoraphanin equation obtained can be used for rough predictions of samples and in case of total phenolic content, the equation showed good correlation. The standard deviation (SD) to standard error of prediction ratio (RPD) and SD to range (RER) were variable for the different quality compounds and showed values that were characteristic of equations suitable for screening purposes or to perform accurate analyses. From the study of the MPLS loadings of the first three terms of the different equations, it can be concluded that some major cell components such as protein and cellulose, highly participated in modelling the equations for glucosinolates.

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.

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.

An approach to the phytochemical profiling of rocket [Eruca sativa (Mill.) Thell].

BACKGROUND: Eruca sativa (rocket) contains a wide range of compounds with nutraceutical and organoleptical properties. This research aimed to characterise the nutraceutical interest of four rocket accessions by analysis of glucosinolates, isothiocyanates, phenolics, carotenoids and carbohydrates. Different methods based on chromatographic separation with ultraviolet absorbance or mass spectrometry detection were used. RESULTS: The total content of glucosinolates ranged from 14.02 to 28.24 µmol g(-1) of dry weight. Glucoraphanin represented up to 52% of the total glucosinolates in leaves of one accession. Accessions showed differences in the hydrolysis of glucoraphanin to the isothiocyanate sulforaphane. No correlation between these compounds was observed, which insisted differences in the myrosinase activity within accessions. Rocket leaves had variable phenolic profiles represented by quercetin-3-glucoside, rutin, myricetin, quercetin and ferulic and p-coumaric acids. A high variability was observed for the total carotenoids ranged from 16.2 to 275 µg g(-1) with lutein as the main carotenoid. Glucose was the predominant sugar, representing >70% of the total soluble carbohydrates. CONCLUSIONS: Some accessions could be candidates for future breeding programmes because of their pattern of beneficial compounds for human health. However, further research is essential to evaluate the biological activity of these accessions before designing functional food.

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.

Modulation of genotoxicity and cytotoxicity by radish grown in metal-contaminated soils.

Members of the Brassicaceae family are known for their anticarcinogenic and genetic material protective effects. However, many of the species of this family accumulate high amounts of metals, which is an undesirable feature. Radish (Raphanus sativus L.) has shown to accumulate metals in roots to a higher extent than others members of Brassicaceae. The main objectives of this work are (i) to study the distribution of the accumulated As, Pb and Cd in radish plants and (ii) to establish the genotoxic, antigenotoxic and cytotoxic activities of the root and shoot of this vegetable. Results indicate that (i) the shoots of radish accumulate higher concentrations of metal(oid)s than roots; (ii) the shoots were genotoxic at the different concentrations studied, with the root showing such genotoxic effect only at the highest concentration assayed; (iii) the antigenotoxic potential of radish is reduced in plants with high metal content and (iv) the tumouricide activities of the radish plants were negatively correlated to their metal(oid) contents. An interaction between metal(oid)s and the isotyocianates (hydrolysis products of the glucosinolates) contained in the radish is suggested as the main modulator agents of the genotoxic activity of the plants grown in contaminated soils with metal(oid)s.

Quantification of glucosinolates in leaves of leaf rape (Brassica napus ssp. pabularia) by near-infrared spectroscopy.

The potential of near-infrared spectroscopy (NIRS) for screening the total glucosinolate (t-GSL) content, and also, the aliphatic glucosinolates gluconapin (GNA), glucobrassicanapin (GBN), progoitrin (PRO), glucoalyssin (GAL), and the indole glucosinolate glucobrassicin (GBS) in the leaf rape (Brassica napus L. ssp. pabularia DC), was assessed. This crop is grown for edible leaves for both fodder and human consumption. In Galicia (northwestern Spain) it is highly appreciated for human nutrition and have the common name of "nabicol". A collection of 36 local populations of nabicol was analysed by NIRS for glucosinolate composition. The reference values for glucosinolates, as they were obtained by high performance liquid chromatography on the leaf samples, were regressed against different spectral transformations by modified partial least-squares (MPLS) regression. The coefficients of determination in cross-validation (r2) shown by the equations for t-GSL, GNA, GBN, PRO, GAL and GBS were, respectively, 0.88, 0.73, 0.81, 0.78, 0.37 and 0.41. The standard deviation to standard error of cross-validation ratio, were for these constituents, as follows: t-GSL, 2.96; GNA, 1.94; GBN, 2.31; PRO, 2.11; GAL, 1.27, and GBS, 1.29. These results show that the equations developed for total glucosinolates, as well as those for gluconapin, glucobrassicanapin and progoitrin, can be used for screening these compounds in the leaves of this species. In addition, the glucoalyssin and glucobrassicin equations obtained, can be used to identify those samples with low and high contents. From the study of the MPLS loadings of the first three terms of the different equations, it can be concluded that some major cell components as protein and cellulose, highly participated in modelling the equations for glucosinolates.

Visible and near-infrared spectroscopy as a technique for screening the inorganic arsenic content in the red crayfish (procambarus clarkii Girard).

The potential of near-infrared spectroscopy (NIRS) for screening the inorganic arsenic (i-As) content in the red crayfish (Procambarus clarkii Girard 1852) was assessed. Sixty-two samples belonging to this species were freeze-dried and scanned by NIRS. The i-As contents of the samples were obtained by acid digestion-solvent extraction followed by hydride generation atomic absorption spectrometry and were regressed against different spectral transformations by modified partial least-squares (MPLS) regression. Second derivative transformation equations of the raw optical data, previously standardized by applying standard normal variate and de-trending algorithms, resulted in a coefficient of determination in the cross-validation (1-VR) of 0.84, indicative of equations of good quantitative information. The standard error of cross-validation to standard deviation ratio, shown by the second derivative equation, was similar to those obtained for other trace metal calibrations reported in NIRS reflectance. Spectral information related to chromophores and lipids of the red crayfish tissues, and also the plant matter contained in their stomachs, were the main organic components used by MPLS for modeling the selected prediction equation. This pioneering use of NIRS to predict the i-As content in red crayfish represents an important savings in time and cost of analysis.

Use of near-infrared spectroscopy for screening the individual and total glucosinolate contents in Indian mustard seed (Brassica juncea L. Czern. & Coss.).

The potential of near-infrared spectroscopy (NIRS) for screening the sinigrin, gluconapin, 4-hydroxyglucobrassicin, and total glucosinolate contents of Indian mustard (Brassica juncea L. Czern. & Coss.) seed was assessed. Intact seed samples of this species were analyzed by NIRS and their reference values regressed against different spectral transformations by modified partial least-squares (MPLS) regression. The coefficients of determination (r (2)) for sinigrin, gluconapin, 4-hydroxyglucobrassicin, and total glucosinolate contents were, respectively, 0.86, 0.95, 0.33, and 0.82. The standard deviation to standard error of prediction (SEP) ratio, and SEP to standard error of laboratory ratio were for these constituents as follows: sinigrin, 2.59 and 2.70; gluconapin, 4.16 and 2.08; 4-hydroxyglucobrassicin, 1.18 and 1.40; and total glucosinolates, 2.18 and 1.60. By comparison of commercial sinigrin spectrum with the first MPLS loadings of the sinigrin equation, it can be concluded that the molecule of sinigrin has a specific signal in the seed spectrum of Brassica.

Heavy metals and arsenic uptake by wild vegetation in the Guadiamar river area after the toxic spill of the Aznalcóllar mine.

On 25 April 1998, approximately 4.5 hm(3) of pyritic sludge, containing 5000 mg of As kg(-1) among other pollutants, was spilled into the Agrio and Guadiamar rivers and the surrounding agricultural areas (Aznalcóllar, Seville, Southern Spain). Many trace metals such as Pb, Cu, Zn, Cd, Tl, Sb and As reached the Doñana National Park, the largest wetland area in Europe, affecting soils, different plant and animal species. In order to recuperate the affected lands by employing plants capable of accumulating high levels of contaminants in shoots, periodical field surveys have been made to identify the metal-tolerant species that are spontaneously growing in the polluted soils, and are able to uptake one or various of the contaminants. Among the 99 different plant species studied, Anchusa azurea, Beta vulgaris, Chamaemelum fuscatum, Convolvulus arvensis, Cynodon dactylon, Diplotaxis virgata, Erodium aethiopicum, Lavatera cretica, Malva nicaeensis, Silybum marianum and, above all, Amaranthus blitoides highlight as the most promising to be used in the remediation of the affected area.