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.

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.

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.

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 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.