•Vitexin-2-O-xyloside was purified from Beta vulgaris cicla seeds.•Betalains were purified from red beet root by anionic exchange chromatography.•Betalains increase vitexin-2-O-xyloside cytotoxicity ...in CaCo-2 colon cancer cells.•The cytotoxic effect is mediated by activation of an intrinsic apoptotic pathway.
Vitexin-2-O-xyloside (XVX) from Beta vulgaris var. cicla L. (BVc) seeds, betaxanthin (R1) and betacyanin (R2) fractions from Beta vulgaris var. rubra L. (BVr) roots were combined and tested for cytotoxicity in CaCo-2 colon cancer cells. XVX was the most cytotoxic molecule, but the combination of XVX with R1 and R2 significantly prolonged its cytotoxicity. Cytotoxicity was mediated by the intrinsic apoptotic pathway, as shown by an increase in Bcl2-like protein 4, cleaved Poly ADP-Ribosyl Polymerase 1 and cleaved Caspase 3 levels with a parallel decrease in anti-apoptotic protein B-cell leukemia/lymphoma 2 levels. R1 and R2, used alone or in combination, reduced oxidative stress triggered by H2O2 in CaCo-2 cells. Betalains dampened cyclooxygenase-2 and interleukin-8 mRNA expression after lipopolysaccharide induction in CaCo-2, showing an anti-inflammatory action. Our results support the use of a cocktail of R1, R2 and XVX as a chemopreventive tool against colon cancer.
Avenanthramides (AVNs) are natural polyphenols obtained from oat sprouts and can also be chemically synthetized. The aim of the present study was to assess the anticancer, anti-inflammatory and ...antioxidant effects of individual synthetized AVNs (s-2c, s-2p, s-2f) and a natural AVN mixture (n-MIX) on CaCo-2 and Hep3B cancer cells. In CaCo-2, the AVN s-2c was found to be the most cytotoxic followed by the n-MIX. In Hep3B cells, a marked cytotoxic effect was found but no significant difference was observed between the synthesized AVNs and the n-MIX. In both CaCo-2 and Hep3B cells, natural and synthetic AVNs activated caspases 8 and 3, and the n-MIX and the AVN s-2c were also able to activate caspase 2. Both synthetic and natural AVNs downregulated pro-survival genes hTERT, COX-2 and MDR1, inhibited the activity of pro-inflammatory COX-2 enzyme and reduced prostaglandin E2 levels, showing the potent chemopreventive effects of these oat-derived phytochemicals. Synthetic AVN s-2c was found to have the highest chemical antioxidant capacity, as indicated by ORAC, DPPH and ABTS values, whereas all AVNs and n-MIX were shown to have similar intracellular antioxidant activity, evaluated by means of the DCFH-DA assay. As AVNs have high bioavailability in humans, results of this study suggest that oat-based foods, fortified with AVNs, could be an alternative to produce functional foods with anticancer, anti-inflammatory and antioxidant effects for health benefits.
The basic ingredients used to make the Italian soffritto were studied in order to define the polyphenol, antioxidant capacity and lycopene content of homemade or commercial tomato sauces, as well as ...their contribute in whole wheat or refined wheat pasta. The addition of aromatic herbs to sauces increased polyphenols and antioxidant capacity, with basil providing the biggest boost, whereas ready-made commercial tomato sauces showed the lowest antioxidant values. Cooked whole wheat pasta with homemade tomato sauce offers an enormous amount of antioxidants, which could protect against oxidative stress. Keywords: antioxidant activity, extra virgin olive oil, lycopene, polyphenols, tomato sauces, vegetables and aromatic herbs
Betacyanins (BC) were purified from beetroot (Beta vulgaris var. rubra L.) and tested, alone or in combination with vitexin-2-O-xyloside (XVX) from Beta vulgaris var. cicla L., for their ability to ...reduce the proliferation rate in T24 bladder cancer cells. Combination of BC and XVX exhibited a synergistic effect concerning the inhibition of proliferation in T24 cancer cells at 24 and 48 h but not after 72 h of incubation. The induction of apoptosis was evidenced by means of fluorescence activated cell sorting (FACS) analysis, as well as through the increase in caspase 3 and 8 activities. Using RTqPCR experiments, it was shown that the combination of XVX + BC was able to enhance the expression levels of pro-apoptotic BAX and downregulate anti-apoptotic BIRC5 (survivin), as well as pro-survival CTNNB1 (β-catenin). The most evident effect of BC was the increase of the activity of caspase 8, leading to induction of extrinsic apoptosis. Moreover, XVX, BC and their combination showed no cytotoxic effect on normal human skin NCTC 2544 keratinocytes. These results demonstrated the efficacy and the mechanisms of the action of BC and XVX, extracted from edible plants, and suggested that a diet or a nutrition supplement, enriched with these bioactive molecules, could be used in the prevention of human bladder cancer.
The molecular components of a phenolic fraction (P2), obtained from liquid chromatography of a Swiss Chard (
Beta vulgaris subsp.
cycla) extract, were identified using HPLC-ESI-MS/MS. The primary P2 ...components were: vitexin-2″
O-rhamnoside, its demethylated form 2″-xylosylvitexin, isorhamnetin 3-gentiobioside, and rutin. P2 “in toto” and the single components were characterized for antioxidant capacity, antimitotic activity on MCF-7 human breast cancer cells and for toxicity to human lymphocytes and macrophages. P2 inhibited MCF-7 cell proliferation (IC
50 value=9
μg/ml) without inducing apoptosis, showed no toxicity to human lymphocytes and slight toxicity to macrophages. Vitexin-2″
O-rhamnoside strongly inhibited DNA synthesis in MCF-7 cells, whereas 2″-xylosylvitexin and isorhamnetin 3-gentiobioside were activators; combinations of activators and inhibitors maintained the over-all inhibitory effect.
Vegetables of
Rubus species are known to have antimicrobial properties mainly due to its high content in phenolic compounds. Among the 37 potentially pathogenic fungi screened with crude methanolic ...extract from micropropagated shoots of
Rubus ulmifolius Schott, we show that the 70% of the species resulted variably sensitive to methanolic extract. Of the phenolic fractions obtained from the crude methanolic extract by hydrophobic interaction chromatography, those rich in tannins resulted active against the fungal strains tested, whereas those containing chlorogenic, caftaric acid and caffeoyl derivatives resulted partially effective. Our results suggest a potential utilization of the in vitro plant cultures of
R. ulmifolius to provide standardized extracts from plant material grown in uniform conditions and available year round, which could be useful as natural antifungal agents.
Antioxidant capacity of extra‐virgin olive oils Ninfali, Paolino; Aluigi, Gianfranca; Bacchiocca, Mara ...
Journal of the American Oil Chemists' Society,
March 2001, Letnik:
78, Številka:
3
Journal Article
Recenzirano
In this study, the oxygen radical absorbance capacity (ORAC) of vegetable oils was investigated using a spectrofluorometric method, which measures the protection of the phenolic substances of the oil ...on the β‐phycoerythrin fluorescence decay in comparison with Trolox. More than 97% of the phenolic substances was extracted from the oil using methanol, and the methanolic extract was then used for the ORAC and the total phenolics assay. We found a significant correlation between ORAC values of different olive oils and the total amount of phenolics. For extra‐virgin olive oils, maximal ORAC values reached 6.20±0.31 μmol Trolox equivalent/g, while refined and seed oils showed values in the 1–1.5 μmol Trolox equivalent/g range. Our method is useful to assess the quality of olive oils and to predict, in combination with the rancidity tests, their stability against oxidation.
Vegetables are the most important sources of phenolics in the Mediterranean diet. Phenolics, especially flavonoids, are suggested as being essential bioactive compounds providing health benefits. In ...this study, twenty-seven vegetables, fifteen aromatic herbs and some spices consumed in Central Italy (the Marches region) were studied to reveal total phenolic, flavonoid and flavanol content as well as their antioxidant capacity measured by the oxygen radical absorbance capacity (ORAC) method. A comparison in terms of antioxidant capacity was made between different salads, as well as between salads to which aromatic herbs had been added. Lemon balm and marjoram at a concentration of 1.5 % w/w increased by 150 % and 200 % respectively the antioxidant capacity of a salad portion. A 200 g portion of a salad enriched with marjoram corresponded to an intake of 200 (SD 10) mg phenolics and 4000 (SD 300) ORAC units (micromol Trolox equivalents). Olive oils and wine or apple vinegars were the salad dressings that provided the highest increase in antioxidant capacity. Among the spices tested, cumin and fresh ginger made the most significant contribution to the antioxidant capacity. The results are useful in surveying the antioxidant parameters of vegetables, herbs and spices produced and consumed in our geographical area as well as in quantifying the daily intake of phenolics and ORAC units. The results can be used in public health campaigns to stimulate the consumption of vegetables able to provide significant health protection in order to prevent chronic diseases.
Oxygen Radical Absorbance Capacity (ORAC), phenolic and flavonoid determinations were performed on ready-to-eat fresh or cooked vegetables, sprouts, frozen vegetables and fresh and dehydrated fruits. ...The peel and pulp of fresh fruit was compared as well. In the minimally processed vegetables, the reduction of phenolic and ORAC values ranged from 10 to 40% in comparison with fresh vegetables; a 80% reduction was found in frozen vegetables, depending on the texture of the vegetable and the consequent blanching time. Some sprouts were shown to possess a high ORAC and can be considered useful ingredients to increase the antioxidant capacity of salads. Dried fruits showed a 25-55% decrease in ORAC when compared with fresh fruits. In two cultivars of apple and pear, the ORAC value of the peel was 6-9 fold higher than the one of the pulp. The results are discussed from the standpoint of nutritional value and quality of the adopted processing technology
Questo lavoro presenta l'applicazione del metodo ORAC, ovvero della capacità di assorbimento dei radicali perossilici, da parte di estratti vegetali e frutti. La determinazione del parametro ORAC, della concentrazione di polifenoli e flavonoidi è stata effettuata su vegetali freschi o cotti pronti per l'uso, su germogli di vari semi, vegetali congelati, frutti disidratati e frutti freschi. Sui frutti freschi è stato effettuato un confronto fra la buccia e la polpa. I valori ORAC dei vegetali trasformati e pronti per l'uso mostravano un decremento variabile tra il 10 e il 40% rispetto ai vegetali freschi; nei vegetali surgelati il decremento massimo rilevato è stato dell'80%, a seconda della durezza del vegetale e del corrispondente tempo di blanching. I frutti disidratati mostravano un decremento di ORAC, rispetto ai freschi, variabile dal 25 al 55%. In due cultivar di mele e pere, l'ORAC della buccia era 6-9 volte più elevato del valore della polpa. I risultati sono discussi dal punto di vista del valore nutrizionale e della qualità della tecnologia di trasformazione
The phenolic and oxygen radical absorbance capacity (ORAC) values have been measured in six fresh and frozen vegetables (beet green, spinach, broccoli, carrot, onion, and celery) from the same ...cultivar by analyzing the whole juice (WJ) and the acetonic extract of the squeezed pulp. To exploit the effect of the acid environment on the stability and recovery of the phenolics, perchloric acid (PCA) was added directly to WJ and to the pulp before the extraction with acetone. In both fresh and frozen vegetables, PCA markedly increased the recovery of phenolics extracted from the pulp, but PCA had no effect on the WJ. Four of six frozen vegetables showed lower phenolic and ORAC values than the fresh vegetables, whereas in the other two cases, values were significantly higher compared to fresh samples. Among the fresh vegetables, beet green showed the highest ORAC and phenolic values; however, when measured in two different cultivars of beet green, the ORAC value showed as much as 4.5-fold variation, whereas total phenolics and flavonoids showed 1.2- and 3.5-fold variations, respectively. The results show that total phenolics and ORAC, compared in fresh and frozen vegetables, represent an index of the mildness of blanching in the industry of frozen vegetables and provide a measure of the gap in antioxidants in the diet of people who consume frozen instead of fresh vegetables. The plant genotype is an important source of variabilty in the ORAC value, which can be conveniently used to increase the intake of antioxidants from vegetables. Keywords: Vegetable juices; antioxidants; phenolic compounds; oxygen radical absorbance capacity (ORAC); fresh and frozen vegetables
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