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Combined treatment of several natural polyphenols and chemotherapeutic agents is more effective comparing to the drug alone in inhibiting cancer cell growth. Polyphenolic artichoke extracts (AEs) have been shown to have anticancer properties by triggering apoptosis or reactive oxygen species- (ROS-) mediated senescence when used at high or low doses, respectively. Our aim was to explore the chemosensitizing potential of AEs in order to enhance the efficacy of conventional chemotherapy in breast cancer cells. We employed breast cancer cell lines to assess the potential synergistic effect of a combined treatment of AEs/paclitaxel (PTX) or AEs/adriamycin (ADR) and to determine the underlying mechanisms correlated to this potential therapeutic approach. Our data shows that AEs/PTX reduced cell proliferation by increasing DNA damage response (DDR) mediated by Flap endonuclease 1 (FEN1) downregulation that results into enhanced breast cancer cell sensitivity to chemotherapeutic drugs. We demonstrated that ROS/Nrf2 and p-ERK pathways are two molecular mechanisms involved in the synergistic effect of AEs plus PTX treatment. To highlight the role of ROS herein, we report that the addition of antioxidant N-acetylcysteine (NAC) significantly decreased the antiproliferative effect of the combined treatment. A combined therapy could be able to reduce the dose of chemotherapeutic drugs, minimizing toxicity and side effects. Our results suggest the use of artichoke polyphenols as ROS-mediated sensitizers of chemotherapy paving the way for innovative and promising natural compound-based therapeutic strategies in oncology.

Processing tomato is a widespread crop in the Mediterranean area where often there are problems of high salinity of irrigation water with considerable harmful effects on yield. Pyraclostrobin is a strobilurin based fungicide (PBF) having a broad range of applications. Strobilurins are reported to have biostimulant effect on plant mitigating abiotic stress. Therefore, the objective of this work was to investigate the ability of PBF to improve gas exchange parameters, chlorophyll, activity of antioxidative enzymes as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), yield characteristics, and water use efficiency (WUE) of tomato under salinity. A two-year research was carried out in Southern Italy, on tomato cv Coronel grown in pots under plastic greenhouse, to compare two soil salinity levels (electrical conductivity, ECe = 1.1 and 5.4 dS m −1 ) in combination with or without PBF. As expected, salinity had harmful effects on physiological and biochemical parameters of tomato that in turn affected yield and WUE, but improved fruit quality. In fact, salinity reduced fruit mean weight (19.0%) and yield (21.4%), and increased fruit blossom-end rot (55.7%), total soluble solids (18.2%) and dry matter (18.5%) content. Overall, PBF increased leaf chlorophyll content (6.1%) and the activity of SOD, POD, CAT and APX, mainly under salinity. Moreover, it reduced stomatal conductance (12.5%) and transpiration (11.7%), but improved assimilation rate (7.8%) and intrinsic WUE (23.3%), that in turn increased yield (8.1%) and yield WUE (6.5%). The improvement in yield produced by PBF was highest in salt stressed plants. In view of the positive effects of PBF, its use should be promoted in defence programs of tomato crop, above all in areas with salinity problems.

Polyphenolic extracts from the edible part of artichoke (Cynara scolymusL.) have been shown to be potential chemopreventive and anticancer dietary compounds. High doses of polyphenolic extracts (AEs) induce apoptosis and decrease the invasive potential of the human breast cancer cell line, MDA-MB231. However, the molecular mechanism underlying AEs antiproliferative effects is not completely understood. We demonstrate that chronic and low doses of AEs treatment at sublethal concentrations suppress human breast cancer cell growth via a caspases-independent mechanism. Furthermore, AEs exposure induces a significant increase of senescence-associatedβ-galactosidase (SA-β-gal) staining and upregulation of tumour suppressor genes,p16INK4aandp21Cip1/Waf1in MDA-MB231 cells. AEs treatment leads to epigenetic alterations in cancer cells, modulating DNA hypomethylation and lysine acetylation levels in total proteins. Cell growth arrest correlates with increased reactive oxygen species (ROS) production in AEs treated breast cancer cells. Inhibition of ROS generation by N-acetylcysteine (NAC) attenuates the antiproliferative effect. These findings demonstrate that chronic AEs treatment inhibits breast cancer cell growth via the induction of premature senescence through epigenetic and ROS-mediated mechanisms. Our results suggest that artichoke polyphenols could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a nonconventional, adjuvant therapy.

Summary Fresh-cut ‘Big Top’ nectarines were dipped in 2% (w/v) ascorbic acid–1% (w/v) calcium lactate and stored at 4 °C for up to 12 days in 10 kPa O2- and 10 kPa CO2-modified atmosphere packaging (MAP). The used microperforated plastic film allowed O2 and CO2 concentrations to reach steady values from the fifth day in storage onwards. Samples stored in MAP after chemical dipping showed the highest visual quality score, slight browning symptoms, increment in firmness and very low ethanol and acetaldehyde content. The chemical dipping also increased antioxidant capacity, probably due to the effect of ascorbic acid. The results suggested that the control of yeasts was mainly exerted by MAP, whereas only a slight effect was achieved by the chemical dipping. Therefore, MAP plus ascorbic acid/calcium lactate dipping was the best combination to preserve phytochemical content, antioxidant capacity and microbiological safety of fresh-cut nectarines during storage.

The quality of leafy vegetables has to be guaranteed for consumers over the whole postharvest period, usually limited to 5–7 days. The analyses to evaluate the quality of vegetables are very time- and resource consuming, so the use of qualitative markers can be much useful. The aim of this work was to evaluate the use of thermoluminescence (TL) parameters as qualitative markers of fresh-cut leafy vegetables during the shelf life. TL is a technique consisting of a cooling, followed by the progressive warming, of a preilluminated sample to reveal the different types of charge pairs as successive emission bands, which are resolved better than the corresponding decay phases recorded at constant temperature. Experiments were performed on rocket (Diplotaxis tenuifolia L.) stored at 2 °C for 7 days. During storage, several changes in TL glow curves were found. The position of the peaks showed a shift to higher temperature. The area of the peaks, relating to the photosystem II (20–65 °C), grew up lightly; whereas in the temperature range that detects lipidic peroxidation (65–140 °C), the TL emission became more than twice. These changes demonstrated that, during the shelf life, a progressive destabilization of PSII centres occurred and that lipid peroxidation products were accumulated in membranes. TL could be used to estimate the damages immediately after as well as during the storage period. This is the first time that TL was used to evaluate the quality of fresh-cut vegetables products during the shelf life.

A cationic soluble peroxidase isoenzyme (CysPrx) has been purified and characterized from artichoke ( Cynara cardunculus subsp. scolymus (L.) Hegi) leaves by combination of aqueous two phase extraction, ion exchange chromatography, and gel filtration. The purification fold was 149 and the activity recovery 5.5%. CysPrx was stable from 5 to 45 °C with a pH optimum around 5.5; the pI was 8.3 and the MW of 37.7 ± 1.5 kDa. MALDI-TOF MS analysis provided partial peptide sequences and resolved CysPrx isoenzyme into two putative isoforms. The presence of these isoforms was confirmed by the isolation of full-length cDNA encoding CysPrx that generate two slightly different sequences coding for two putative CysPrx: CysPrx1 and CysPrx2. The obtained MS peptides showed a 35% coverage with 100% identity with the two CysPrx deduced protein sequences. A molecular modeling analysis was carried out to predict in silico the protein structure and compare it with other plant Prx structures. Considering that CysPrx is quite stable, the study carried out in this paper will offer new insights for the production of the recombinant protein for utilization of CysPrx as an alternative Prx for food technology, biomedical analysis and bioremediation.

Many epidemiological studies suggest that diet particulary rich in fruit and vegetables have cancer preventive properties. The beneficial effects of these diets are attributable, at least in part, to polyphenols that have emerged as very promising anticancer bioactive compounds. We report that polyphenolic extracts from the edible part of artichoke show a potential chemopreventive and anticancer properties on several cancer cell lines. High dose of extracts of artichoke (AEs) reduced cell viability and inhibited cell growth in a dose dependent-manner. In particular AEs triggered apoptosis and modulate other tumour related features such as migration and invasion in highly metastatic breast cancer cells. In addition, we provide evidences that low dose of AEs-treatment inhibits breast cancer cell growth via the induction of premature senescence through epigenetic and ROS-mediated mechanisms. These findings demonstrated that high dose-AEs activate apoptotic machinery whereas low level treatment induce senescence in cancer cells. Since apoptosis and cellular pro-senescence are considered relevant anticancer therapeutic mechanisms, artichoke polyphenols extracts from the edible part, could be a promising dietary tool either in cancer chemoprevention or/and in cancer treatment as a non-conventional, adjuvant therapy.

Postharvest treatments with extracts from two wild edible plants ( Orobanche crenata and Sanguisorba minor ), water solutions of two inorganic salts (calcium chloride, CaCl 2 , and sodium bicarbonate, NaHCO 3 ), and their combination (i.e., extracts with added CaCl 2 or NaHCO 3 ), were assayed to control sweet cherry postharvest diseases. Three extract concentrations for each plant were assayed, corresponding to 0.170, 0.340, and 0.510 g dry matter/mL and to 0.125, 0.250, and 0.500 g dry matter/mL for S. minor and O. crenata , respectively. At the lowest and the highest concentrations tested, S. minor extract was able to inhibit rot development in stored fruit by 79 and 89%, respectively, with an efficacy comparable to that of CaCl 2 and NaHCO 3 ; for O. crenata extract such inhibition ranged between 64 and 76%, respectively. A dose effect was observed only for O. crenata . Moreover, the level of control was not improved by the combined application of plant extracts and salts. HPLC analysis of O. crenata extract showed verbascoside as the main phenolic compound, being about 95% of total phenolics; S. minor phenolic pattern appeared to be more complex, due to the presence of caffeic acid derivatives, quercetin-3-glucoside, kaempferol-3-glucoside and other quercetin, kaempferol, and luteolin derivatives, as well as many other unidentified compounds. Residues of phenolics resulting from plant extracts in treated sweet cherries after storage were below the analytical limit of detection. The study demonstrated that S. minor and O. crenata extracts might represent an alternative organic mean for controlling sweet cherry postharvest decay.

The most recent trend in research on probiotic bacteria aims at the exploitation of bioactive bacterial compounds that are responsible for health-promoting effects and suitable for medical applications. Therefore, the main purpose of this study was to ascertain if the immunomodulatory effects of L. paracasei strains on dendritic cells (DCs) were caused by bacterial metabolites released in the culture medium. For that reason, bacterial strains were grown in two media generally used for the culture of DCs, and the effects of culture filtrates on the maturation of DCs and cytokine production were evaluated. Moreover, to reveal potential synergistic effects on the immunomodulation of DCs, an artichoke phenolic extract (APE) was added to the media before bacterial growth. The experiments pointed out an interesting anti-inflammatory activity of a culture filtrate obtained after growing a probiotic L. paracasei strain in one of the media supplemented with APE. Therefore, this culture filtrate--which combines the anti-inflammatory activity and the other well-known health-promoting properties of artichoke phenolic compounds--could represent the basis for future particular exploitations.

1 Istituto di Scienze delle Produzioni Alimentari-CNR, Via Amendola, 122/O 70126 Bari, Italy 2 lstituto di Scienze delle Produzioni Alimentari-CNR, Sezione di Torino c/o Biolndustry Park del Canavese, Via Ribes, 5-10010 Colleretto Giacosa (TO), Italy 3 Dipartimento di Scienze Agro-Ambientali, Chimica e Difesa Vegetale, Facolta di Agraria, Universita degli Studi di Foggia, Via Napoli, 25-71100 Foggia, Italy Peroxidases are part of a large group of enzymes associated with cell wall biosynthesis, response to injury, disease, resistance and wound repair. Among peroxidase isoenzymes, a soluble cationic peroxidase (ALSP), not yet described, has been partially purified and characterized from artichoke leaves. The enzyme was shown to be a glycoprotein with a molecular weight of 51 000 and an isoelectric point of 9. The substrate specificity of the ALSP is characteristic of class III (guaiacol-type) peroxidases. The ALSP was partially purified by ammonium sulfate precipitation, gel filtration, affinity chromatography, anionic exchange high-performance liquid chromatography and isoelectrofocusing. The increase in specific activity was 43 times compared to the crude extract as estimated by the guaiacol assay. Three ALSP fragments were sequenced by tandem mass spectrometry de novo sequencing method.

Seeds of wild species and varieties of Vigna were screened for their tannins and α-amylase inhibitor contents as defensive compounds against cowpea weevil. Seed coats contained condensed tannins that were positively correlated to their colour but not to their resistance against the insect. The α-amylase inhibitors were present in different amount in cotyledons of all species analysed. Amongst the cultivated lines assayed, Vigna unguiculata TVu 2027, an accession identified as moderately resistant, was found to contain the higher amount of α-amylase inhibitor. When wild species were considered, V luteola and V vexillata (two resistant species) showed the highest content of α-amylase inhibitors. In addition, two cultivated accessions (Vita 7 and IT 84E-1-108) of cowpea seeds, both classified as susceptible accessions, showing a different degree of bruchid damage in storage, were also analysed. No α-amylase inhibitory activity was found in cotyledons of undamaged Vita 7 seeds, while the seed coat tannin content was found to be 13 times higher in undamaged Vita 7 seeds than in IT 84E-1-108 infested seeds. These latter results support the hypothesis that seed coat tannins must also be considered in biochemical defence mechanisms, which can deter, poison or starve bruchid larvae that feed on cowpea seeds. Copyright © 2004 Society of Chemical Industry

Tomato for processing is a very widespread crop in the Mediterranean area where often there are problems of high salinity of irrigation water. It's well known that the high salinity creates physiological problems with considerable negative effects on production. Pyraclostrobin belongs to a class of fungicide (strobilurins) having a broad spectrum of applications, with preventive, curative, translaminar and locosystemic properties. In the literature it is reported that strobilurins can affect the plant metabolism resulting in the increase of yield, dry matter, content of both chlorophyll and protein and delay senescence. In addition, it was observed plant water balance modification by reducing root water uptake, resulting in the postponement of soil dehydration, so it may contribute to yield enhancement. Because many effects of salt stress are comparable to water stress, we may speculate that Pyraclostrobin could alleviate detrimental effects of salinity on plants. This study focused on the interactive effect of salinity and Pyraclostrobin application on tomato grown in pots under plastic tunnel. The objective was to investigate the complementary properties of Pyraclostrobin in the improvement of tomato physiological (SPAD, gas exchange, activity of antioxidative enzymes as SOD, CAT, POD, APX), yield and fruit quality responses under salinity. A two-year research (2010 and 2011) was carried out in Basilicata region, southern Italy, on cv Coronel to compare two soil salinity levels - 1.0 (S0) and 5.4 dS m-1 (S1) - and two fungicide treatments - application of fungicides without strobilurins (F0); application of a strobilurin based fungicide (Cabrio® Duo) (F1). The treatments were arranged in a split plot design with seven replicates. On overall, when plants are treated with Pyraclostrobin, a considerable increase in POD, APX and CAT activity occurred, whereas no significant changes were observed in SOD. Different extent of changes in enzyme activity was observed in the two parts of the plant: POD increased only in roots, APX in roots as well as in leaves, and CAT only in leaves. In some sampling date, the increase in antioxidant enzyme activities was higher in saline stressed plants. The amount of chlorophyll, measured in SPAD units, did not differed between salinity levels, instead, F1 showed the increase of about 6%. Gas exchanges were influenced by salinity level and fungicide treatments. In particular, S1 has shown values of net assimilation (A), transpiration (T) and stomatal conductance (gs) respectively of about 17, 26 and 22% lower than S0, while the water use efficiency (WUE) was not influenced. Pyraclostrobin reduced A and T by about 8%, and gs by about 17%. Salinity reduced fruit mean weight by 19%, total and marketable yield by 25 and 21%, respectively, and increased fruit blossom-end rot (BER) by 57%. Among the qualitative parameters, salinity caused the increase of total soluble solids (TSS) and dry matter (DM) of the fruits by 22 and 20% respectively. Pyraclostrobin increased fruits mean weight by 6%, total and marketable yield by about 8% and reduced BER by 19%. The improvement in total and marketable yield caused by Pyraclostrobin was higher in the crop with salinity stress (11.6%) in respect to the non saline one (6%). The reduction in A caused by Pyraclostrobin seems contradictory with the yield increase, so further research is needed to study the physiological mechanisms involved when Pyraclostrobin was applied. In view of the positive effects observed with the application of Pyraclostrobin, it should be promoted its use in programs of protection of tomato crop, above all in areas with salinity problems.

The content of chlorogenic acid, (+)-catechin, (-)-epicatechin, phloretin glycosides, and quercetin glycosides in fresh and stored Golden Delicious apples (Malus domestica Borkh) was determined. The relative amount of phenolics in the peel, with the exception of chlorogenic acid and (-)-epicatechin, was higher than that in the flesh. In addition, quercetin glycosides were detected only in the skin. These compounds were tested for fungicidal activity against Phlyctaena vagabunda Desm., the causal agent of a postharvest rot. Chlorogenic acid only inhibited P. vagabunda spore germination and mycelial growth in vitro. Changes of apple phenolics and polyphenol oxidase activity during cold storage and the biological activity of these phenolics have also been analyzed with reference to the development of quiescent infections during cold storage plus shelf life at room temperature. The results obtained suggested that phloridzin and chlorogenic acid in combination with polyphenol oxidase activity could function to arrest P. vagabunda in quiescent infections associated with immature and ripening apple fruit.

The chemical characterization of phenolic ex- tracts of salad burnet (Sanguisorba minor Scop. s.l.) and broomrape (Orobanche crenata Forsk.) was performed. Active fractions were separated and characterized and, in the case of O. crenata, two phenolic compounds, verbascoside and is- overbascoside, were quantitatively extracted, purified and characterized. These compounds proved to be effective in reducing the growth of some important fungi responsible for the decay of fresh fruit and vegetables in postharvest. Ver- bascoside showed significant activity against Penicillium italicum, fairly inhibited Monilinia laxa, P. expansum, and Aspergillus carbonarius, and showed little activity against Botrytis cine- rea, M. fructicola and P. digitatum. Isoverbasco- side completely inhibited B. cinerea, P. digitatum, P. italicum, and P. expansum; it fairly inhibited M. laxa and A. carbonarius; while it showed to be less effective against M. fructicola. The obtained results support the possible use of some wild edible plants as a source of phenolic substances for the postharvest biological control of fresh fruit and vegetable rots.

Efficient utilization of saline land for food cultivation can increase agricultural productivity and rural income. To obtain information on the salt tolerance/susceptibility of wild chicory (Cichorium intybus L.), the influence of salinity (0–260 mM NaCl) on chicory seed germination and that of two salinity levels of irrigation water (100 and 200 mM NaCl) on plant growth, antioxidative enzyme activity, and accumulation of proline and malondialdehyde (MDA) were investigated. The trials were performed outdoors, in pots placed under a protective glass covering, for two consecutive years. Seeds showed a high capacity to germinate in saline conditions. The use of 100 mM NaCl solution resulted in 81 % germination, whereas seed germinability decreased below 40 % using salt concentrations above 200 mM NaCl. Wild chicory showed tolerance to medium salinity (100 mM NaCl), whereas a drastic reduction in biomass was observed when 200 mM NaCl solution was used for irrigation. MDA, present in higher amounts in leaves than in roots, decreased in both tissues under increasing salinity. Proline content increased remarkably with the level of salt stress, more so in roots than in leaves. In salt stress conditions, the activity of antioxidant enzymes (APX, CAT, POD, SOD) was enhanced. The electrophoretic patterns of the studied enzymes showed that the salinity of irrigation water affected only the intensity of bands, but did not activate new isoforms. Our results suggest that wild chicory is able to grow in soil with moderate salinity by activating antioxidative responses both in roots and leaves.

The human breast cancer cell line, estrogen receptor negative, MDA-MB231, was used to evaluate the antitumor effect of polyphenolic extracts from the edible part of artichokes (AEs). Treatment of cancer cells reduced cell viability and inhibited cell growth in a dose-dependent manner. Importantly, AEs did not have any effect on normal breast epithelial cell line, MCF10A. Chlorogenic acid (ChA), the most representative component of the polyphenolic fraction of artichoke, had no prominent effects on the cell death rate of MDA-MB231 cells. The addition of AEs to the cells, rather than ChA, triggered apoptosis via a mitochondrial and a death-receptor pathway, as shown by the activation of caspase-9 and caspase-8, respectively. Furthermore, an increase of the Bax:Bcl2 ratio and up-regulation of cyclin-dependent kinase inhibitor, p21(WAF1), crucial apoptotic players, were documented. According to our data on activation of caspase-9, a loss of mitochondrial transmembrane potential (Ψ(m)) was shown. Cell motility and invasion capabilities were remarkably inhibited by AEs-treatment in highly invasive MDA-MB231 cells. In addition, a significant decrease of proteolytic activity of metalloproteinase-2 protein (MMP-2), involved in degrading components of the extracellular matrix, was detected. Our findings indicate that AEs reduced cell viability, inhibited cell growth, triggered apoptotic mechanisms, and showed inhibitory properties against the invasive behavior of MDA-MB231 cancer cell line. Altogether, these data indicate the potential chemopreventive activity of artichoke polyphenolic extracts.

The use of plant extracts could be a useful alternative to synthetic fungicides in the management of rot fungi during postharvest handling of fruit and vegetables. The aim of this study was to assess the in vitro and in vivo activity of extracts obtained from nine wild edible herbaceous species (Borago officinalis, Orobanche crenata, Plantago coronopus, P. lanceolata, Sanguisorba minor, Silene vulgaris, Sonchus asper, Sonchus oleraceus, and Taraxacum officinale) against some important postharvest pathogens, i.e. Botrytis cinerea, Monilinia laxa, Penicillium digitatum, P. expansum, P. italicum, Aspergillus carbonarius, and A. niger. Phenolic composition of all extracts was evaluated by HPLC. Several derivatives of caffeic acid, of the flavones apigenin and luteolin, and of the flavonols kaempferol and quercetin, were identified. Extracts from S. minor and O. crenata showed the highest efficacy in all the trials. In particular, S. minor completely inhibited in vitro the conidial germination of M. laxa, P. digitatum, P. italicum, and A. niger and strongly reduced those of B. cinerea; O. crenata extract showed a lower but still significant reduction of conidial germination on all the tested fungi. Moreover, the extracts from both species were effective in reducing the germ tube elongation also when a slight inhibition of conidial germination was observed. In many cases, a dose effect was observed, with an increase of antifungal activity as the phenolic concentration increased. In trials performed on wounded fruit, S. minor extract completely inhibited brown rot on apricots and nectarines; O. crenata extract strongly reduced grey mould, brown rot, and green mould on table grapes, apricots and nectarines, and oranges, respectively. The inhibition efficacy of extracts was ascribed to the presence of some caffeic acid derivatives and/or flavonoids. HPLC phenolic analyses provided useful information to identify the possible active compounds. © 2011 Elsevier B.V.

Soluble (SP), ionically bound (IBP) and covalently bound (CBP) peroxidases (POD) from artichoke leaves and heads have been characterized for the main biochemical parameters. The three PODs, in both leaves and heads, showed the major apparent catalytic efficiency (vmax,app/Km,app) towards ferulic acid, even though, in some cases, they showed higher affinity (Km,app) for other substrates. In leaves, SP and IBP showed higher Km,app for ferulic and chlorogenic acids, and CBP for ferulic and caffeic acids. In heads, SP showed higher Km,app for chlorogenic acid, IBP for caffeic and ferulic acids, and CBP for ferulic acid. It was shown that pH optimum for PODs ranged between 5.0 and 6.0 in leaves. In heads, pH optimum for SP and IBP was 5.5, while CBP presented a very low activity in a wide pH range. All PODs showed high thermal stability but different ability to regenerate: the bound forms were more able to regenerate than the soluble one. The results obtained show that (i) CBP from heads is able to work under very different cellular conditions, (ii) all PODs, in both tissues, have a high apparent catalytic efficiency for ferulic acid, which could explain the effective involvement of POD in lignin biosynthesis, (iii) in heads, high Km,app of SP for chlorogenic acid, particularly abundant in artichoke, could justify the possible involvement of PODs in browning mechanism, and (iv) in heat-processed artichoke, the ability of PODs to regenerate could contribute to oxidation and loss of product quality., Okarakterizirana su mnoga biokemijska svojstva topljivih, ionski i kovalentno vezanih peroksidaza ekstrahiranih iz lišća i glavica artičoke. Sva tri oblika peroksidaza, iz lišća i glavica, pokazala su veliku prividnu katalitičku djelotvornost (vmax,app/Km,app) prema feruličnoj kiselini, iako su u nekoliko slučajeva imala veći afinitet (Km,app) prema drugim supstratima. Topljive i ionski vezane peroksidaze iz lišća artičoke imale su veći afinitet za feruličnu i klorogenu kiselinu, a kovalentno vezane za feruličnu i kafeinsku kiselinu. Topljive peroksidaze iz glavica artičoke pokazale su veći afinitet prema klorogenoj kiselini, ionski vezane prema kafeinskoj i feruličnoj, a kovalentno vezane peroksidaze samo prema feruličnoj kiselini. Optimalna pH-vrijednost za aktivnost peroksidaza iz lišća bila je od 5 do 6, a za aktivnost topljivih i ionski vezanih peroksidaza iz glavica 5,5. Kovalentno vezane peroksidaze ekstrahirane iz glavica artičoke imale su malu aktivnost pri svim pH-vrijednostima. Sve su peroksidaze imale veliku termostabilnost, ali različitu sposobnost regeneracije: vezani su se oblici bolje regenerirali od topljivih oblika. Iz dobivenih rezultata izvedeni su sljedeći zaključci: (i) kovalentno vezane peroksidaze iz glavica djeluju u različitim staničnim uvjetima, (ii) sve ekstrahirane peroksidaze imaju veliku prividnu katalitičku djelotvornost prema feruličnoj kiselini, što objašnjava ulogu peroksidaza u biosintezi lignina, (iii) veliki afinitet topljive peroksidaze iz glavica prema klorogenoj kiselini, osobito zastupljenoj u artičokama, mogao bi objasniti ulogu peroksidaza u posmeđivanju glavica i (iv) sposobnost regeneracije peroksidaza uzrokuje oksidaciju i gubitak kakvoće artičoke tijekom kuhanja.

Cultured rat hepatocytes and human hepatoma HepG2 cells were used to evaluate the hepatoprotective properties of polyphenolic extracts from the edible part of artichoke (AE). The hepatocytes were exposed to H2O2generated in situ by glucose oxidase and were treated with either AE, or pure chlorogenic acid (ChA) or with the well known antioxidant, N, N'-diphenyl-p-phenilenediamine (DPPD). Addition of glucose oxidase to the culture medium caused depletion of intracellular glutathione (GSH) content, accumulation of malondialdehyde (MDA) in the cultures, as a lipid peroxidation indicator, and cell death. These results demonstrated that AE protected cells from the oxidative stress caused by glucose oxidase, comparable to DPPD. Furthermore, AE, as well as ChA, prevented the loss of total GSH and the accumulation of MDA. Treatment of HepG2 cells for 24 h with AE reduced cell viability in a dose-dependent manner, however, ChA had no prominent effects on the cell death rate. Similarly, AE rather than ChA induced apoptosis, measured by flow cytometric analysis of annexin and by activation of caspase-3, in HepG2 cells. Our findings indicate that AE had a marked antioxidative potential that protects hepatocytes from an oxidative stress. Furthermore, AE reduced cell viability and had an apoptotic activity on a human liver cancer cell line.

The content of chlorogenic acid, dicaffeoylquinic acids, apigenin-7-glucoside and inulin (expressed as fructose after hydrolysis) was determined by HPLC on the edible portion of the buds (hearts). Chlorogenic acid content ranged from 330 to 820 mg 100g(-1) f.w. in the cv. Bayrampasa and 'CB-07', respectively, while dicaffeoylquinic acids ranged from 450 mg 100g(-1) f.w. in the 'Violetto di Provenza' and 'Camard' to 1400 mg 100g(-1) f.w. in the 'Violetto di Putignano' and 'Violetto di Toscana'. Apigenin-7-glucoside was nearly undetected in some cultivars (i.e. 'Hyerois') and reached the highest value of 56 mg 100g(-1) f.w. in the cv. Domestica di Castelvetrano.

Changes in some biochemical parameters during cold storage of artichoke heads (cv. Violetto di Provenza) harvested in winter and spring seasons and packaged with two different types of plastic films were investigated. Heads were stored at I IC for five weeks. Intermediate permeability film was able to preserve the commercial quality of the product for five and four weeks in winter and spring harvested heads. respectively. At the end of the storage period, heads packed with this film showed good turgidity, absence of off-flavours and browning. Instead the other film induced asphyxia symptoms in heads after the first week in storage. Regarding biochemical parameters, a small increase in chlorogenic and dicaffeoylquinic acids content was observed, more marked in spring harvested heads and controlled by the wrapping film. Fructose and sucrose showed an increasing trend, whereas glucose and inulin tended to decrease during storage. Also in this case the film packing presence contributed to counteract these trends. Finally, enzyme activities were weakly influenced by the wrapping film. During the storage period, POD markedly increased in winter harvested heads, whereas PPO showed a slight decreasing trend in spring trials.

A very large amount of phenol-polluted waters is formed from the production of olive oil (olive mill waste water, OMWW) and their disposal represents a serious problem. The aim of this study was to investigate the use of peroxidase (POD) from artichoke (Cynara cardunculus L. subsp. scolymus (L.) Hayek) leaves to remove phenols present in OMWW. The POD catalyzes the polymerization and precipitation of aqueous phenols. This application could be useful, because in the Mediterranean region a large amount of OMWW as well as a lot of artichoke scraps resulting from artichoke processing industry, are produced. So, it is possible to consider this biomass (leaves and external bud bracts) as a useful and cheap source of peroxidase. The enzyme extraction was performed by homogenization and separation of pigments using an aqueous two phase polymer system (polyethylene glycol/(NH4)2SO4), that allowed the accumulation of POD in the salt phase. The optimal reaction conditions were evaluated. The phenolic concentration was assayed by Folin-Ciocalteu method. Preliminary results showed that the optimal conditions for enzyme activity were in a broad range of both pH (from 4 to 7) and temperature (from 5 to 50°C). In optimal enzymatic conditions, a reduction of more than 60% of initial phenolic concentration was observed.

This paper provides information about the phenolic composition of Eruca vesicaria (L.) Cav. (garden rocket) and Diplotaxis tenuifolia (L.) DC. (wild rocket). Kaempferol, quercetin and isorhamnetin glycosides were found in E. vesicaria. Quercetin and isorhamnetin glycosides were detected in D. tenuifolia. In addition, the latter contained other unidentified phenolic substances. The influence of sowing date on phenolic content was investigated. Two sowing times were evaluated: February-March and July-August. Plants were grown in open-field and harvested about 40 days after sowing. The phenolic content of spring-harvested plants was higher than summer-harvested ones: a difference of 2-3 times in the former and up to 7 times in the latter was noticed. As to flavonoids, harvesting time appears to influence particularly some quercetin and isorhamnetin derivatives found just in trace in summer-harvested plants.

The use of peroxidase (POD) from artichoke (Cynara cardunculus L. subsp. scolymus (L.) Hayek) leaves to remove phenols present in olive mill waste water (OMWW) was studied. The enzyme extraction was performed using an aqueous two phase polymer system. The phenol concentration was assayed using the Folin-Ciocalteu method. The optimal reaction conditions were evaluated. The highest phenol removal was obtained using 4 mM H(2)O(2) and an incubation of 24 hours. The enzyme showed a good activity in a broad range of pH (from 4 to 7) and temperature (from 5 to 50 degrees C). In optimal enzymatic conditions, a reduction of more than 60% of initial phenol concentration was observed. High pressure liquid chromatography (HPLC) analysis of OMWW untreated and treated with POD extracts revealed that enzyme treatment brought about changes in the original OMWW polyphenolic profile. In particular the removal of verbascoside, hydroxytyrosol, and two caffeic acid derivatives was noticed. The results showed that the soluble POD from artichoke leaves could have a promising perspective in OMWW phenol removal, due to its broad pH and temperature working range and its cheap source.