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1.
Food Chem ; 369: 130958, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34479011

RESUMO

The aim of this study was to determine the influence of the microwave heating method (MWH) on selected determinants of the nutritional value of human milk (HM) and compare to the effect exerted by the standard convection heating (CH) method, including holder pasteurization (HoP). It was showed that using MWH under conditions assumed to ensure microbiological safety, changes in the level of the nutrients were not observed. In these conditions concentration of fatty acids (FAs), lipid peroxides (LP) and α-lactalbumin (α-La) were on a similar level as in raw milk, and furosine was not formed. MWH treatment of HM led to slight increase in the malonaldehyde (MDA) and protein carbonyls (PC) content. However, MDA content in HM as a result of MWH was lower than after application CH.

2.
J Photochem Photobiol B ; 222: 112263, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34339994

RESUMO

The biosynthesis of polyphenolic compounds in cabbage waste, outer green leaves of white head cabbage (Brassica oleracea L. var. capitata subvar. alba), was stimulated by postharvest irradiation with UVB lamps or sunlight. Both treatments boosted the content of kaempferol and quercetin glycosides, especially in the basal leaf zone, as determined by the HPLC analysis of leaf extracts and by a non-destructive optical sensor. The destructive analysis of samples irradiated by the sun for 6 days at the end of October 2015 in Skierniewice (Poland) showed an increase of leaf flavonols by 82% with respect to controls. The treatment by a broadband UVB fluorescent lamp, with irradiance of 0.38 W m-2 in the 290-315 nm range (and 0.59 W m-2 in the UVA region) for 12 h per day at 17 °C along with a white light of about 20 µmol m-2 s-1, produced a flavonols increase of 58% with respect to controls. The kinetics of flavonols accumulation in response to the photochemical treatments was monitored with the FLAV non-destructive index. The initial FLAV rate under the sun was proportional to the daily radiation doses with a better correlation for the sun global irradiance (R2 = 0.973), followed by the UVA (R2 = 0.965) and UVB (R2 = 0.899) irradiance. The sunlight turned out to be more efficient than the UVB lamp in increasing the flavonols level of waste leaves, because of a significant role played by UVA and visible solar radiation in the regulation of the flavonoid accumulation in cabbage. The FLAV index increase induced on the adaxial leaf side was accompanied by a lower but still significant FLAV increase on the unirradiated abaxial side, likely due to a systemic signaling by mean of the long-distance movement of macromolecules. Our present investigation provides useful data for the optimization of postharvest photochemical protocols of cabbage waste valorization. It can represent a novel and alternative tool of vegetable waste management for the recovery of beneficial phytochemicals.


Assuntos
Brassica/efeitos da radiação , Luz , Brassica/química , Brassica/metabolismo , Clorofila/química , Cromatografia Líquida de Alta Pressão , Flavonóis/análise , Flavonóis/metabolismo , Armazenamento de Alimentos , Folhas de Planta/química , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Espectrometria de Fluorescência , Raios Ultravioleta
3.
Antioxidants (Basel) ; 10(8)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34439525

RESUMO

Most literature data indicate that the diet rich in plant products reduces the risk of developing chronic non-communicable diseases and cancer. Brassica vegetables are almost exclusively synthesizing glucosinolates. Glucosinolates are higher in sprouts than in mature plants, being related to the activity of the specific myrosinase involved in the degradation of glucosinolates during developmental stages. This study compares the content of total glucosinolates with their profile and, rare in the literature, also with products of their degradation. Average amounts of total glucosinolates in young shoots of white and red headed cabbage were 26.23 µmol/g d.m. and 27.93 µmol/g d.m., respectively. In addition, antioxidative properties of 21-day-old shoots of white and red headed cabbage were assessed. The area of negative peaks after post-column derivatization with the ABTS reagent, indicating antioxidant activity of young red cabbage shoots, was 20185, compared to the value determined for young white cabbage shoots (3929). The results clearly indicate that, regardless of the vegetable species, young shoots of white and red headed cabbage can be an important source of bioactive substances in the diet, thus being an important element of cancer chemoprevention.

4.
Food Chem ; 362: 130132, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34082297

RESUMO

This study presents methods that can be used to assess the health quality of products containing betalains. The paper compares and verifies data on the phytochemical composition of three different pigmented beetroot cultivars using spectrophotometric, HPLC-DAD, HPTLC and LC-Q-Orbitrap-HRMS techniques. Additionally, we compared the total antioxidant activity in both the cell-free and cellular systems. Betalain contribution to antioxidant activity was also determined using post-column derivatization and it was found that in the case of red beetroot it is about 50%. Photometric measurements are recommended for a simple and inexpensive analysis of the total betacyanin and betaxanthin content. Liquid chromatography techniques produced more precise information on phytochemical composition in the tested samples. The combination of liquid chromatography with high-resolution mass spectrometry produced the largest amount of quantitative and qualitative data; in beetroot samples sixty-four phytochemicals have been identified therefore, this approach is recommended for more detailed metabolomics studies.


Assuntos
Antioxidantes/química , Beta vulgaris/química , Betalaínas/análise , Espectrometria de Massas/métodos , Antioxidantes/análise , Antioxidantes/farmacologia , Betacianinas/análise , Betalaínas/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Análise de Alimentos/métodos , Células HT29 , Humanos , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/isolamento & purificação , Ácidos Picolínicos/análise , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Software
5.
Free Radic Biol Med ; 154: 48-61, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32360591

RESUMO

Numerous studies have shown, rather disappointingly, that isolated bioactive phytochemicals are not as biologically effective as natural plant products. Such a discrepancy may be explained by the concept of food synergy, which was verified in this research for cocoa extract versus its major components with regard to cancer chemoprevention. The evaluation embraced the relationship between redox properties evaluated in cell-free systems with the aid of free radicals scavenging method and differential pulse voltammetry, and redox associated anticarcinogenic activities (cellular antioxidant activity, cytotoxicity, nutrigenomic activity) in human colon adenocarcinoma cell line exposed to either cocoa powder extract or artificial mixtures of cocoa bioactives at matching concentrations. In contrast to expectations, our results showed that the stepwise enrichment with antioxidants caused no gradual increase in the antioxidant activity of the model mixtures; also, these model mixtures did not reach the reducing potential of cocoa in the cell-free systems or cellular model employed. Further, the biological activities examined in colon adenocarcinoma cells did not alter in a stepwise manner that could reflect the gradual changes in composition of bioactive ingredients. In conclusion, the experiments presented here showed that the growing complexity of a mixture of phytochemicals seems to create a new redox bioactive substance rather than enrich the mixture with new activities, characteristic of the compound added. It follows that no simple, predictable relationship can be expected between the chemopreventive potential and the composition of real food items containing a complicated set of non-toxic redox active ingredients. Our observations suggest that the interactions between different bioactive compounds and food matrix components are cooperating factors determining the final bioactivity of foods.


Assuntos
Cacau , Chocolate , Antioxidantes/farmacologia , Chocolate/análise , Humanos , Nutrigenômica , Extratos Vegetais/farmacologia , Polifenóis/análise , Pós
6.
Foods ; 8(12)2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31817505

RESUMO

The aim of this research was to correlate the composition of phenolic compounds and bioactivities (antioxidant, cytotoxic, antigenotoxic, and influence on selected enzymatic activities) exhibited by extracts from differently pigmented raspberry (yellow and red), grape (white and red), mulberry (white and black), and currant (white, red, and black) varieties. It was presumed that phytocomplexes of the same species will be similar while differing significantly only by the content of anthocyanins in colored varieties, which will impact biological properties. Additionally, to compare food matrix embedded and isolated anthocyanins, the influence of purified solution, in concentrations matching the total concentration of anthocyanins in appropriate colored plant samples, on investigated biological activities was studied. The phenolic compound composition and antioxidant profiles showed that anthocyanin content was correlated only with antioxidant capacity of tested plant extracts. The other determined biological activities failed to reveal any simple relationship between chemopreventive potential and anthocyanin composition in fruits studied nor any similarity to biological properties of isolated cyanidin-3-O-glucoside. These observations indirectly support the food synergy concept, that points to interactions between different phytochemicals as a factor deciding about the final bioactivity of edible plants.

7.
J Sci Food Agric ; 99(12): 5499-5507, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31099412

RESUMO

BACKGROUND: Brassica plants contain a wide spectrum of bioactive components that are responsible for their health-promoting potential such as vitamins, polyphenols and glucosinolates. This study attempted to relate the composition of bioactive phytochemicals and chosen biological activities (antioxidant, cytotoxic, anti-genotoxic, and influence on enzymatic activities) for extracts from differently pigmented cabbage (white and red) and cauliflower (white and purple) varieties. The assumption was that tested varieties of the same plant would exhibit similar chemical composition differing mostly in anthocyanin content and that the latter will be reflected in biological activity. RESULTS: Profiles of antioxidants obtained using post-column derivatization with ABTS radical confirmed, that the content and composition of anthocyanins is strongly correlated with the antioxidant capacity of tested plant extracts measured by spectrophotometric methods (ABTS, FC, DPPH, FRAP), and Cellular Antioxidant Activity (CAA) test. The results of determinations of other biological activities showed that opposite to purified bioactive phytochemicals, in the case of actual plant foods, there was no simple relationship between anthocyanin content and chemopreventive potential. CONCLUSION: Obtained results suggest that there must be some kind of interaction between different phytochemicals, which decides on the final health promoting activity of edible plants as suggested by for example the food synergy concept. © 2019 Society of Chemical Industry.


Assuntos
Brassica/química , Compostos Fitoquímicos/química , Extratos Vegetais/química , Antocianinas/química , Antioxidantes/química , Brassica/classificação , Cor , Glucosinolatos/química , Polifenóis/química
8.
Int J Food Sci Nutr ; 70(4): 442-452, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30632828

RESUMO

Betalains are a group of plant originated pigments with chemopreventive potential. The aim of this study was to relate the composition of betalains and chosen biological activities (antioxidant, cytotoxic, anti-genotoxic and influence on enzymatic activities) for extracts from differently pigmented varieties of prickly pear (yellow, orange and red) and beetroot (white and red). The assumption was that phytocomplexes of tested varieties of the same plant species would exhibit generally similar chemical composition differing mostly in betalain content, which will be reflected by their biological activity. Betalain composition analysis and antioxidant profiles confirmed that the content and composition of these pigments is strongly correlated with the antioxidant activity of tested plant extracts measured by spectrophotometric methods and CAA test. However, the results of determinations of other biological activities showed that in the case of actual plant foods, there was no simple relationship between betalain content or composition and chemopreventive potential.


Assuntos
Beta vulgaris/química , Betalaínas/análise , Opuntia/química , Pigmentos Biológicos/análise , Antioxidantes/análise , Dano ao DNA , Frutas/química , Células HT29 , Humanos , Estresse Oxidativo , Extratos Vegetais/química
9.
Pathogens ; 7(2)2018 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-29921833

RESUMO

The aim of our work was to check if one of the products of natural origin, namely honey bee propolis, may be an alternative or supplement to currently used antifungal agents. The activity of 50 ethanolic extracts of propolis (EEPs), harvested in Polish apiaries, was tested on a group of 69 clinical isolates of C. albicans. Most of the EEPs showed satisfactory activity, with minimum fungicidal concentrations (MFC) mainly in the range of 0.08⁻1.25% (v/v). Eradication of biofilm from polystyrene microtitration plates in 50% (MBEC50, Minimum Biofilm Eradication Concentration) required concentrations in the range of 0.04% (v/v) to more than 1.25% (v/v). High activity was also observed in eradication of biofilm formed by C. glabrata and C. krusei on the surfaces of PVC (Polyvinyl Chloride) and silicone catheters. EEPs at subinhibitory concentrations inhibited yeast-to-mycelia morphological transformation of C. albicans in liquid medium and mycelial growth on solid medium. A synergistic effect was observed for the action of EEP in combination with fluconazole (FLU) and voriconazole (VOR) against C. albicans. In the presence of EEP at concentrations as low as 0.02%, the MICs of FLU and VOR were 256 to 32 times lower in comparison to those of the drug alone. Evidence for the fungal cell membrane as the most probable target of EEPs are presented.

10.
Redox Biol ; 17: 355-366, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29803149

RESUMO

Redox homeostasis involves factors that ensure proper function of cells. The excess reactive oxygen species (ROS) leads to oxidative stress and increased risk of oxidative damage to cellular components. In contrast, upon reductive stress, insufficient ROS abundance may result in faulty cell signalling. It may be expected that dietary antioxidants, depending on their standard reduction potentials (E°), will affect both scenarios. In our study, for the first time, we systematically tested the relationship among E°, chemical properties, and biological effects in HT29 cells for a series of structurally different catechins and a major endogenous antioxidant - glutathione (GSH), at both physiological and dietary concentrations. Among chemical antioxidant activity tests, the strongest correlation with E° was seen using a DPPH assay. The values of E° were also highly correlated with cellular antioxidant activity (CAA) values determined in HT29 cells. Our results indicated that physiological concentrations (1-10 µM) of tested catechins stabilized the redox status of cells, which was not exhibited at higher concentrations. This stabilization of redox homeostasis was mirrored by constant, dose and E° independent CAA values, uninhibited growth of HT29 cells, modulation of hydrogen peroxide-induced DNA damage, as well as effects at the genomic level, where either up-regulation of three redox-related genes (ALB, CCL5, and HSPA1A) out of 84 in the array (1 µM) or no effect (10 µM) was observed for catechins. Higher catechin concentrations (over 10 µM) increased CAA values in a dose- and E°-dependent manner, caused cell growth inhibition, but surprisingly did not protect HT29 cells against reactive oxygen species (ROS)-induced DNA fragmentation. In conclusion, dose-dependent effects of dietary antioxidants and biological functions potentially modulated by them may become deregulated upon exposure to excessive doses.


Assuntos
Antioxidantes/farmacologia , Catequina/farmacologia , Glutationa/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/química , Catequina/química , Quimiocina CCL5/genética , Dano ao DNA/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Glutationa/genética , Proteínas de Choque Térmico HSP70/genética , Células HT29 , Humanos , Peróxido de Hidrogênio/química , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/toxicidade , Albumina Sérica Humana/genética
11.
J Sci Food Agric ; 97(12): 3937-3947, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28188641

RESUMO

BACKGROUND: The phytochemicals of two apple cultivars (Yellow Transparent and Early Geneva) protected in two ways, conventionally with chemical pesticides or by effective microorganisms (EM), were compared. Two types of components were determined: lipids synthesised constitutively and generated via inducible pathways polyphenols along with antioxidant activity and profiles. RESULTS: The antioxidant activities assessed with ABTS, DPPH and Folin-Ciocalteu reagents were about two-fold higher in the case of microbiologically protected apples. The qualitative composition of phenolics determined by LC-DAD-MS varied between cultivars and the part of apples studied, while the method of protection caused mainly differences in concentration of some groups of polyphenols (hydroxycinnamates, flavanols, dihydrochalcones, flavonols, anthocyanins). The apples from biological cultivation contained about 34-54% more phenolics than these from a conventional orchard. In contrast, lipid composition did not differ significantly between apples originating from conventional and bio-crops. CONCLUSION: The results indicate that the advantage of using the EM technology in agriculture may not only be the reduction of consumption of chemical fertilisers and synthetic pesticides, but also, at least in the case of apples, may lead to the production of crops with improved health quality due to the higher content of bioactive phytochemicals. © 2017 Society of Chemical Industry.


Assuntos
Bactérias/metabolismo , Malus/química , Compostos Fitoquímicos/análise , Antioxidantes/análise , Cromatografia Líquida de Alta Pressão , Frutas/química , Frutas/microbiologia , Lipídeos/química , Malus/microbiologia , Doenças das Plantas/prevenção & controle , Polifenóis/análise
12.
Food Chem ; 214: 587-596, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27507514

RESUMO

The procedure for the isothiocyanates (ITCs) determination that involves derivatization with N-acetyl-l-cysteine (NAC) and separation by HPLC was developed. Prior to derivatization, plant ITCs were isolated and purified using solid-phase extraction (SPE). The optimum conditions of derivatization are: 500µL of isopropanolic eluate obtained by SPE combined with 500µL of derivatizing reagent (0.2M NAC and 0.2M NaHCO3 in water) and reaction time of 1h at 50°C. The formed dithiocarbamates are directly analyzed by HPLC coupled with diode array detector and mass spectrometer if required. The method was validated for nine common natural ITCs. Calibration curves were linear (R(2)⩾0.991) within a wide range of concentrations and limits of detection were below 4.9nmol/mL. The recoveries were in the range of 83.3-103.7%, with relative standard deviations <5.4%. The developed method has been successfully applied to determine ITCs in broccoli, white cabbage, garden cress, radish, horseradish and papaya.


Assuntos
Acetilcisteína/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Isotiocianatos/química , Espectrometria de Massas/métodos , Plantas/química , Extração em Fase Sólida/métodos
13.
J Agric Food Chem ; 64(1): 85-94, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26679081

RESUMO

A multiparametric optical sensor was used to nondestructively estimate phytochemical compounds in white cabbage leaves directly in the field. An experimental site of 1980 white cabbages (Brassica oleracea L. var. capitata subvar. alba), under different nitrogen (N) treatments, was mapped by measuring leaf transmittance and chlorophyll fluorescence screening in one leaf/cabbage head. The provided indices of flavonols (FLAV) and chlorophyll (CHL) displayed the opposite response to applied N rates, decreasing and increasing, respectively. The combined nitrogen balance index (NBI = CHL/FLAV) calculated was able to discriminate all of the plots under four N regimens (0, 100, 200, and 400 kg/ha) and was correlated with the leaf N content determined destructively. CHL and FLAV were properly calibrated against chlorophyll (R(2) = 0.945) and flavonol (R(2) = 0.932) leaf contents, respectively, by using a homographic fit function. The proposed optical sensing of cabbage crops can be used to estimate the N status of plants and perform precision fertilization to maintain acceptable crop yield levels and, additionally, to rapidly detect health-promoting flavonol antioxidants in Brassica plants.


Assuntos
Brassica/química , Clorofila/química , Flavonóis/química , Nitrogênio/metabolismo , Imagem Óptica/métodos , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Flavonóis/metabolismo , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo
14.
J Food Sci Technol ; 52(9): 5736-44, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26344987

RESUMO

ABSTRACT: Coffee being the beverage consumed worldwide is also a very competitive commodity. Consequently, producers seek ways of attracting consumers by proposing e.g. novel ingredient combinations usually without evaluating their health quality. In this study, variations in health-promoting determinants for five special purpose coffee brews were characterized. The major bioactive components - chlorogenic acids (CAs) - detected by HPLC-DAD-MS included caffeoyl-, feruloyl- and dicaffeoylquinic acids. Roasting declined CAs content by 50 %, while caffeine content increased by about 30 % during this process. In roasted coffee brews studied, CAs content varied from 14.1 to 26.6 mg/g; smaller variations were seen in antioxidant potential (determined by spectrophotometric and cyclic voltammetry assays). Profiles generated by HPLC with post-column on-line antioxidant detection revealed that caffeoylquinic acids were the most abundant antioxidants in samples studied. The highest antioxidative potential exhibited coffee enriched with green coffee extract confirming the soundness of such an approach to obtain healthier products. HIGHLIGHTS: • Special purpose coffees are equivalent to regular ones as regards antioxidant potential. • Caffeoylquinic acids are the most abundant antioxidants in coffee samples studied. • Roasting process causes some degradation of chlorogenic acids but not caffeine. • Special purpose coffees retain health benefits while being more attractive to consumers.

15.
Int J Food Sci Nutr ; 65(6): 692-702, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24827602

RESUMO

The correlation among selenium uptake, the content of bioactive compounds in sprouts, and biological activities triggered in cultured human cells by sprout extracts was investigated. Seeds of Brassica crops and rye were treated with SeO2 water solution. The selenium levels in sprouts increased from 1.0-4.1 to 53.3-382 µg/g dw with no influence on plant physiology according to the indices used. Neither the composition of glucosinolates (GL) in Brassica sprouts nor the myrosinase activity nor the composition of GL breakdown lipophilic products were significantly affected. In all Brassica sprouts, conversion to health-promoting isothiocyanates (ITC) and indoles corresponded to only 1% of total GLs. Low ITC concentration may explain observed lack of induction of glutathione S-transferases (GST) and quinone oxidoreductase (NQO) detoxifying enzymes in HT29 cells exposed to sprout extracts. The insignificant impact on cell growth and genome function suggests that Brassica sprouts may be safe vehicle of selenium to combat its dietary deficiency.


Assuntos
Brassica/metabolismo , Dieta , Germinação , Glucosinolatos/metabolismo , Isotiocianatos/metabolismo , Plântula/metabolismo , Selênio/metabolismo , Anticarcinógenos/farmacologia , Antioxidantes/metabolismo , Técnicas de Cultura de Células , Glutationa Transferase/metabolismo , Glicosídeo Hidrolases/metabolismo , Células HT29 , Humanos , Indóis/metabolismo , Indóis/farmacologia , NAD(P)H Desidrogenase (Quinona)/metabolismo , Extratos Vegetais/farmacologia , Selênio/deficiência , Óxidos de Selênio/metabolismo
16.
Food Chem ; 157: 105-10, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24679758

RESUMO

Meat consumption represents a dietary risk factor increasing the incidence of common cancers, probably due to carcinogenic amines (HAAs) formed upon meat heating. Interestingly, cancers whose incidence is increased by meat consumption, are decreased in populations consuming brassica vegetables regularly. This inverse correlation is attributed to brassica anticarcinogenic components, especially isothiocyanates (ITCs) that stimulate detoxification of food carcinogens. However, ITC reactivity towards amines generating stable thioureas, may also decrease mutagenicity of processed meat. We confirmed here that combining meat with cabbage (fresh or lyophilized), in proportions found in culinary recipes, limited by 17-20% formation of HAAs and significantly lowered mutagenic activity of fried burgers. Moreover, MeIQx mutagenicity was lowered in the presence of ITCs, as well as for synthetic ITC-MeIQx conjugates. This suggests that formation of thioureas could lead to chemical detoxification of food carcinogens, reducing the cancer risk associated with meat consumption.


Assuntos
Brassica/química , Carne/análise , Mutagênicos/análise , Carcinógenos/análise , Compostos Heterocíclicos , Humanos , Incidência , Isotiocianatos , Fatores de Risco
17.
Food Chem ; 141(3): 2198-206, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23870948

RESUMO

Salvia officinalis (SO) and Thymus vulgaris (TV) are medicinal plants well known for their curative powers. However, the molecular mechanisms responsible for these abilities of sage and thyme have not been fully understood yet. In this study we investigated the composition and the quantitative estimation of plant extracts, the protective effects of plant extracts against hydrogen peroxide- and 2,3-dimethoxy-1,4-naphthoquinone-induced DNA damage, and levels of enzymatic and non-enzymatic antioxidants (superoxide dismutase, glutathione peroxidase, glutathione) in human HepG2 cells. To measure antioxidative activity of plant extracts we used three assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The results showed that the oxidant-induced DNA lesions were significantly reduced in cells pre-treated with the plant extracts studied. The observed DNA-protective activity could be explained by both elevation of GPx activity in cells pre-treated with SO and TV and antioxidant activity of SO and TV.


Assuntos
Antioxidantes/metabolismo , Dano ao DNA/efeitos dos fármacos , Oxidantes/toxicidade , Extratos Vegetais/farmacologia , Salvia officinalis/química , Thymus (Planta)/química , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Células Hep G2 , Humanos , Peróxido de Hidrogênio/toxicidade , Naftoquinonas/toxicidade , Superóxido Dismutase/metabolismo
18.
J Chromatogr A ; 1278: 108-15, 2013 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-23352826

RESUMO

Over the past decade, glucosinolates (GLs) present in different tissues of Brassicaceae and their breakdown products, especially isothiocyanates formed after myrosinase catalyzed hydrolysis, have been regarded as not only environment friendly biopesticides for controlling soilborne pathogens, but most importantly as promising anticarcinogenic compounds. For these reasons, the identification and quantitative determination of the content of individual glucosinolates in plant material is of great interest. Among the different analytical approaches available today for determining GLs in brassica plant samples, HPLC analysis of their desulfo derivatives (DS-GLs) according to ISO 9167-1, 1992, method is the most widely used. However, the notorious lack of commercially available standards limits its usefulness. To overcome these limitations, liquid chromatography-electrospray ionisation-mass spectrometry was investigated as a potential method for the identification of DS-GLs. The characteristic pattern of fragmentation either in positive or negative ionisation was established based on mass spectra of 11 DS-GL standards, then proposed for additional over 30 most common desulfated GLs. The applicability of MS detection of DS-GLs was verified for real plant samples, the extracts of 14 kinds of brassica sprouts. The results indicated that this methodology combines a convenient identification of DS-GLs with the well established analytical procedure preferred by many researchers. Thus, incorporation of MS detection into popular ISO method seems to result in an improved and more reliable approach to GLs determination.


Assuntos
Brassicaceae/química , Cromatografia Líquida de Alta Pressão/métodos , Glucosinolatos/análise , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Brassicaceae/crescimento & desenvolvimento
19.
Mutagenesis ; 27(6): 759-69, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22940646

RESUMO

Among nanomaterials, silver nanoparticles (AgNPs) have the broadest and most commercial applications due to their antibacterial properties, highlighting the need for exploring their potential toxicity and underlying mechanisms of action. Our main aim was to investigate whether AgNPs exert toxicity by inducing oxidative damage to DNA in human kidney HEK 293 cells. In addition, we tested whether this damage could be counteracted by plant extracts containing phytochemicals such as swertiamarin, mangiferin and homoorientin with high antioxidant abilities. We show that AgNPs (20 nm) are taken up by cells and localised in vacuoles and cytoplasm. Exposure to 1, 25 or 100 µg/ml AgNPs leads to a significant dose-dependent increase in oxidised DNA base lesions (8-oxo-7,8-dihydroguanine or 8-oxoG) detected by the comet assay after incubation of nucleoids with 8-oxoG DNA glycosylase. Oxidised DNA base lesions and strand breaks caused by AgNPs were diminished by aqueous and methanolic extracts from both haulm and flower of Gentiana asclepiadea.


Assuntos
Dano ao DNA/efeitos dos fármacos , Gentiana/química , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Prata/toxicidade , Antioxidantes/farmacologia , Proliferação de Células , Cromatografia Líquida de Alta Pressão , Ensaio Cometa , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , Células HEK293 , Humanos , Nanopartículas Metálicas/química , Metanol/metabolismo , Prata/química
20.
Environ Toxicol Chem ; 31(11): 2482-9, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22886927

RESUMO

The relationship between the ability to accumulate heavy metals (represented by Cd and Zn) and to synthesize bioactive compounds (represented by glucosinolates [GLS]) was investigated in two cabbage cultivars. Plants were grown in the greenhouse of a phytotron under controlled conditions in soils spiked with two different Zn or Cd concentrations. The measurements of Cd and Zn contents in soil and cabbage (leaf) samples were performed by atomic absorption spectroscopy, whereas GLS levels in cabbage were determined by high-performance liquid chromatography. The ranges of metal contents in soil were 80 to 450 mg/kg dry weight for Zn and 0.3 to 30 mg/kg dry weight for Cd, whereas the levels of accumulated Zn and Cd in cabbage amounted to 15 to 130 and 0.02 to 3 mg/kg dry weight, respectively. After initial symptoms of toxicity, during a later stage of growth, the plants exhibited very good tolerance to both metals. Enhanced biosynthesis of GLS was observed in a dose-dependent manner following exposure to the heavy metals. The GLS content in Zn-exposed cabbage rose from 3.2 to 12 µmol/g dry weight, and the corresponding values for Cd-treated plants were 3.5 to 10 µmol/g dry weight. Thus, the increased soil contamination by metals caused greater accumulation in cabbage, as well as stimulation of GLS biosynthesis. The results obtained point to the high phytoremediation and biofumigation potential of white cabbage.


Assuntos
Brassica/metabolismo , Cádmio/farmacocinética , Glucosinolatos/análise , Poluentes do Solo/farmacocinética , Zinco/farmacocinética , Biodegradação Ambiental , Brassica/crescimento & desenvolvimento , Solo/química
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