Carotenoids, polyphenols and micronutrient profiles of Brassica oleraceae and plum varieties and their contribution to measures of total antioxidant capacity

Antioxidative and anti-proliferative potential of Curculigo orchioides Gaertn in oxidative stress induced cytotoxicity: In vitro, ex vivo and in silico studies

Plant phytoconstituents have been a valuable source of clinically important anticancer agents. Antioxidant and anticancerous activity of plant Curculigo orchioides Gaertn were explored In vitro antioxidant activity, antioxidant enzyme activity of oxidatively stressed tissue, and cell culture studies on human cancer cell lines HepG2, HeLa and MCF-7 were carried out. Active plant fractions were subjected to GC-MS analysis and compounds selected on the basis of their abundance were screened in silico with the help of Auto Dock 4.2 tools with pre-selected antioxidant enzymes. Curculigo orchioides Gaertn plant fractions exhibited significant antioxidant activities by virtue of scavenging of free radicals having IC₅₀ value of ethylacetate fraction (EA) for DPPH radical scavenging assay to be 52.93 ± 0.66 μg/ml. Further, antioxidant enzyme defense of mammalian tissue when treated with plant fractions revealed that enzyme concentrations were refurbished which were increased during oxidative stress. MTT assay on cell lines HepG2, HeLa and MCF-7 presented IC₅₀ values of ethylacetate (EA) fraction as 171.23 ± 2.1 μg/ml, 144.80 ± 1.08 μg/ml and 153.51 μg/ml and aqueous ethylacetate (AEA) fraction as 133.44 ± 1.1 μg/ml, 136.50 ± 0.8 μg/ml and 145.09 μg/ml respectively. Further EA and AEA plant fractions down regulated the levels of antiapoptotic Bcl-2 expression and upregulated the expression of apoptotic proteins caspase-3 and caspase-8 through an intrinsic ROS-mediated mitochondrial dysfunction pathway.

KEY MESSAGE

Key findings explained that fractions of Curculigo orchioides Gaertn inhibited oxidative stress by increasing the antioxidant enzyme content and have anticancerous potential on cancer cell lines HepG2, HeLa and MCF-7.

Proteomic response of inflammatory stimulated intestinal epithelial cells to in vitro digested plums and cabbages rich in carotenoids and polyphenols

Due to their anti-oxidant and anti-inflammatory potential, polyphenol and carotenoid-rich plant foods have been suggested as promising phytochemicals in the prevention of or as adjuvants regarding inflammatory bowel diseases (IBD). In the present study, we investigated whether plum (Italian Plum, Prunus cocomilla), or cabbage (Kale, Brassica oleracea var. sabellica), selected for their high phytochemical content, are able to reduce inflammation in cellular models of the intestinal epithelium, employing proteomic methods. For this purpose, plum/cabbage (carotenoid content: 1.9 mg per 100 g resp. 13 mg per 100 g; polyphenol content: 83 mg per 100 g resp. 27 mg per 100 g) were gastro-intestinally digested, and aliquots exposed (18 h) to either a monoculture (Caco-2) or a triple culture (Caco-2/HT-29-MTX (90 : 10, v/v) with THP-1 like macrophages), stimulated (with LPS, TNF-α, and IL-1β) to induce inflammation. Cells (Caco-2, Caco-2/HT-29-MTX, and THP-1) were then harvested separately, and proteomic analyses of total cell extracts were carried out by 2D-DIGE. In the monoculture, 68 protein-spots were significantly (p < 0.05, expression ratio >1.5) differentially regulated due to the Kale and Italian plum digesta, and in the co-culture 206 protein-spots, compared to digesta without plum/cabbage. These belonged to 27 (monoculture) and 76 (coculture) uniquely identified proteins, suggesting the coculture to be a more sensitive model. Proteins included antioxidant enzymes such as catalase, superoxide dismutase and glutathione-S-transferases. Only 3 proteins were differentially regulated in the THP-1 cells, perhaps as these were only indirectly exposed. The results show promise regarding some aspects related to IBD complications, however, employing phytochemical-rich food items should be further investigated in in vivo trials.

Effect of high-hydrostatic pressure and moderate-intensity pulsed electric field on plum

Moderate intensity pulse electric fields were applied in plum with the aim to increase bioactive compounds content of the fruit, while high-hydrostatic pressure was applied to preserve the purées. High-hydrostatic pressure treatment was compared with an equivalent thermal treatment. The addition of ascorbic acid during purée manufacture was also evaluated. The main objective of this study was to assess the effects on microorganisms, polyphenoloxidase, color and bioactive compounds of high-hydrostatic pressure, or thermal-processed plum purées made of moderate intensity pulse electric field-treated or no-moderate intensity pulse electric field-treated plums, after processing during storage. The application of moderate intensity pulse electric field to plums slightly increased the levels of anthocyanins and the antioxidant activity of purées. The application of Hydrostatic-high pressure (HHP) increased the levels of bioactive compounds in purées, while the thermal treatment preserved better the color during storage. The addition of ascorbic acid during the manufacture of plum purée was an important factor for the final quality of purées. The color and the bioactive compounds content were better preserved in purées with ascorbic acid. The no inactivation of polyphenoloxidase enzyme with treatments applied in this study affected the stability purées. Probably more intense treatments conditions (high-hydrostatic pressure and thermal treatment) would be necessary to reach better quality and shelf life during storage.

Biochemical and biological characterization of two Brassicaceae after their commercial expiry date

Two Brassicaceae (Eruca sativa, Brassica oleracea var. sabauda) were stored in air and under a modified atmosphere for several days after their expiry date and then analyzed. The polyphenol content and composition, as well as the antioxidant activity of the extracts, were assessed, compared to the fresh products. Antimicrobial properties on tester strains (Bacillus cereus, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa) and in vitro anti-proliferative activity were evaluated. The cabbage extracts exhibited antimicrobial activity mainly on the ninth day after the expiry date and retained significant inhibitory effects against colon carcinoma (CaCo-2) cells. The rocket salad extract exhibited antiproliferative but not antimicrobial activity. Overall, our results indicated that they might represent a good source of natural antioxidants with antimicrobial and anti-proliferative activity, also after their expiry date, suggesting their exploitation for the recovery of important biomolecules used in the food and health industry.

Structures and Analysis of Carotenoid Molecules

Modifications of the usual C40 linear and symmetrical carotenoid skeleton give rise to a wide array of structures of carotenes and xanthophylls in plant tissues. These include acyclic, monocyclic and dicyclic carotenoids, along with hydroxy and epoxy xanthophylls and apocarotenoids. Carotenols can be unesterified or esterified (monoester) in one or two (diester) hydroxyl groups with fatty acids. E-Z isomerization increases the array of possible plant carotenoids even further. Screening and especially quantitative analysis are being carried out worldwide. Visible absorption spectrometry and near infrared reflectance spectroscopy have been used for the initial estimation of the total carotenoid content or the principal carotenoid content when large numbers of samples needed to be analyzed within a short time, as would be the case in breeding programs. Although inherently difficult, quantitative analysis of the individual carotenoids is essential. Knowledge of the sources of errors and means to avoid them has led to a large body of reliable quantitative compositional data on carotenoids. Reverse-phase HPLC with a photodiode array detector has been the preferred analytical technique, but UHPLC is increasingly employed. HPLC-MS has been used mainly for identification and NMR has been useful in unequivocally identifying geometric isomers.

Optimised method for the analysis of phenolic compounds from caper (Capparis spinosa L.) berries and monitoring of their changes during fermentation

In this work, an ad hoc method to identify and quantify polyphenols from caper berries was developed on high-performance liquid chromatography/electrospray ionisation source/mass spectrometry (HPLC-ESI-MS). The method was applied during fermentation carried out with Lactobacillus pentosus OM13 (Trial S) and without starter (Trial C). A total of five polyphenols were identified. All samples contained high concentrations of rutin. Epicatechin was found in untreated fruits, on the contrary quercetin was detected during fermentation. Trial S was characterised by a more rapid acidification and lower levels of spoilage microorganisms than Trial C. L. pentosus dominated among the microbial community of both trials and the highest biodiversity, in terms of strains, was displayed by Trial C. Aureobasidium pullulans was the only yeast species found. The analytical method proposed allowed a high polyphenolic compound recovery from untreated and processed caper berries in short time. The starter culture reduced the bitter taste of the final product.

Carotenoid and polyphenol bioaccessibility and cellular uptake from plum and cabbage varieties

Plum and cabbage are rich in carotenoids and polyphenols. However, their bioactivity depends on their release and intestinal uptake. Four varieties of Brassicaceae (Duchy, Scots Kale, Kale, Kalorama) and Prunus (Cherry Plum, Plum 620, Ersinger, Italian Plum) were studied; bioaccessibility following in vitro digestion, cellular uptake (Caco-2 vs. co-culture cell model: Caco-2:HT-29-MTX (90:10%) and colonic fermentation were determined for carotenoids/polyphenols; the influence of certain kitchen preparations was likewise studied. Carotenoids were non-significantly influenced by the latter, while for polyphenols, boiling and steaming significantly reduced total phenolics (p<0.05). Carotenoid bioaccessibility did not differ significantly between Prunus vs. Brassicaceae varieties, but xanthophyll was higher than carotene bioaccessibility (p<0.01). Polyphenol bioaccessibility was low (<10%), possibly compromised by the cream containing test meal. Total carotenoid cellular uptake varied between varieties (0.3-4.1%), being higher for carotenes (4.1%) than for xanthophylls (1.6%, p<0.01), and were higher for the co-culture cell model compared to Caco-2 cells (p<0.01). Total carotenoid recovery in the colonic fraction varied from 4% to 25%. Lower bioaccessibility of carotenes thus appeared to be somewhat counterbalanced by higher cellular uptake. The potential positive role of the mucus layer for cellular uptake and the fate of the colonic digesta deserve further attention in the future.

In Vitro Bioaccessibility and Bioavailability of Iron from Potatoes with Varying Vitamin C, Carotenoid, and Phenolic Concentrations

The bioaccessibility and bioavailability of iron from 12 Andean potato clones were estimated using an in vitro gastrointestinal digestion procedure and the Caco-2 cell line as a model of human intestine, with ferritin formation as a marker of iron absorption. We first showed that 63.7% (for the genotype CIP_311422.016) to 79.0% (for the genotype CIP_311575.003) of the iron is released from the potato tuber matrix during in vitro gastrointestinal digestion and is therefore available at the intestinal level. On average, 32 and 24.5% of the hydrophilic bioactive components, vitamin C and chlorogenic acid, respectively, were also bioaccessible from boiled tubers. Intestinal absorption of intrinsic iron from potato tubers could not be detected using our in vitro Caco-2 cell model. When an extrinsic source of iron (20 μM FeCl3 and 1 mM ascorbic acid) was added to the digestion mixture, iron absorption varied from 1.8 to 8% for the genotypes CIP_311422.016 and CIP_311624.021, respectively, as compared to the reference control. Principal component analysis revealed negative relationships between bioavailable iron values and phenolic concentrations, whereas vitamin C concentrations were positively associated with the ferritin values. Further controlled intervention trials would be needed to conclusively assess the bioavailability of intrinsic iron from potato tubers.

The influence of virus infections on antioxidant levels in the genetically modified plum variety "Honeysweet" (Prunus domestica L.)

It is well-known that polyphenolic compounds are found abundantly in fruit, but various kinds of diseases  lower these levels. This work measures total polyphenolic content, antioxidant activity and the levels of specific important antioxidants in fruits of the genetically modified (GM) plum variety HoneySweet, trees  which were previously inoculated with a range of different virus infections.  These were the Plum Pox virus (PPV), Prune Dwarf virus (PDV) and Apple Chlorotic Leaf-Spot virus (ACLSV). Uninoculated trees were used as controls. Antioxidant activity was measured using four different photometric  methods – DPPH (2,2-diphenyl-1-picrylhydrazyl), DMPD (N-dimethyl-p-phenylenediamine), ABTS (2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) and FRAP (Ferric reducing antioxidant power). Total polyphenol content was measured using the Folin–Ciocalteau method. The profiles of 10 specific antioxidant constituents in the fruits of the GM plum variety HoneySweet were detected and analyzed, since these are of interest for their role in human diets and could play a role in the resistance of plants to viruses. Detection was made using HPLC with UV-VIS detection.  They were: gallic acid, p-coumaric acid, 4-aminobenzoic acid, chlorogenic acid, caffeic acid, ferulic acid, vanillin, rutin and quercetin. The compound with the highest concentration was chlorogenic acid (587 mg/100 g), and that with the lowest was p-coumaric acid (0.95 mg/100 g). Of the four methods of antioxidant activity used, in three the lowest levels of antioxidant activity were seen where the PPV virus was combined with ACLSV, and in three the highest levels were seen in the un-inoculated control without any infection. The highest values of total polyphenols were seen in the control (65.3 mg/100 g), followed by infection of PPV, then treatment PPV, PDV and ACLSV, then treatment PPV and PDV and finally the lowest levels were seen in treatment PPV and ACLSV (44.2 mg/100 g), which was also that with the lowest antioxidant activity.

Antihyperglycemic, antihyperlipidemic and antioxidant activity of phenolic rich extract of Brassica oleraceae var gongylodes on streptozotocin induced Wistar rats

Cruciferous vegetables, in particular those included into the Brassica genus, are good sources of a variety of nutrients and health-promoting phytochemicals. Phenolic compounds are the major antioxidants of Brassica; hence the contribution of Brassica vegetables to health improvement has largely been associated to their antioxidant capacity. This study aimed to assess anti-diabetic, antilipidemic, and antioxidant activity of phenolic rich extract of Brassica oleraceae var gongylodes (BOvG) in Wistar rats. The findings revealed that the administration of BOvG extract to diabetic rats significantly reduced fasting blood glucose by 64% within 7 days of treatment. Additionally, BOvG extract was also observed to normalize the diabetic rats’ lipid profile and HbA1c (Glycated hemoglobin). BOvG extract also showed protection of liver- kidney functions, which was evidenced by the significant decrease in Blood Urea Nitrogen (BUN), Serum glutamic oxaloacetic transaminase (SGOT) and Serum glutamic pyruvic transaminase (SGPT). The treatment also improved the antioxidant status of the diabetic rats where the enzymatic activities of Catalase (CAT) and Super Oxide Dismutase (SOD) were significantly increased. Furthermore, RP-HPLC analysis detected chlorogenic acid, rutin, and sinapic acid against known standards in BOvG extract. Hence, the present investigation suggests that BOvG phenolic rich extract (as a multi-component therapy) exhibited anti-diabetic, antilipidemic and antioxidant properties in STZ-induced diabetic rats.

Chlorophylls and carotenoids of kiwifruit puree are affected similarly or less by microwave than by conventional heat processing and storage

The impact of microwave (1000 W - 340 s) and conventional heat (97 °C - 30s) pasteurisation and storage (4, 10, 22 °C for up to 63 d) on total and individual carotenoids and chlorophylls in kiwifruit puree was evaluated. Bioaccessibility of carotenoids, before and after pasteurisation and storage, was also studied. Microwaves and conventional heating led to marked changes in the chlorophyll (42-100% losses) and carotenoid (62-91% losses) content. First- and second-order kinetics appropriately explained the degradation of total carotenoids and chlorophylls over time, respectively. Pasteurised samples showed significantly (p < 0.05) enhanced stability of these pigments, with microwaves (k = 0.007-0.031100 g mg(-1) day(-1) at 4-22 °C) promoting chlorophyll stability to a greater extent than conventional heating (k = 0.0015-0.034100 g mg(-1) day(-1) at 4-22 °C). Bioaccessibility of carotenoids remained (p < 0.05) unaffected by processing and storage. These results highlighted that the pigment composition of microwaved kiwifruit was more similar to that of the fresh fruit and better preserved during storage.

In vitro antioxidative and binding properties of phenolics in traditional, citrus and exotic fruits

Many polyphenols bind proteins, therefore our research was focused on the potential of protein binding to polyphenols of investigated fruits and their health-related effects. The contents of polyphenols and related antioxidant activities of traditional, citrus and exotic fruits were compared. The presence of polyphenols (flavonoids and phenolic acids) in the investigated samples and their interaction with human serum albumin (HSA) was studied by HPLC, Fourier Transform Infrared (FT-IR) and three dimensional fluorescence spectroscopy (3D-FL). The highest levels of polyphenols, antioxidant and binding capacities were found in red and blond grapefruits (citrus group), followed by strawberries and apples (traditional group) and mangosteen and kiwi fruit (exotic fruit), which also contained the highest levels of protocatechuic, p-coumaric, ferulic acids and quercetin. In conclusion, for the first time, the interaction of the polyphenols with human serum albumin was evaluated by fluorometry/FTIR. The obtained binding profiles allowed the comparison of three different groups of fruits. A mixture of these fruits can be recommended for consumption.

Effect of cooking on the concentration of bioactive compounds in broccoli (Brassica oleracea var. Avenger) and cauliflower (Brassica oleracea var. Alphina F1) grown in an organic system

Brassica vegetables have been shown to have antioxidant capacities due to the presence of carotenoids, flavonoids and vitamins. This study evaluates the influence of different processing conditions (boiling, steaming, microwaving and sous vide) on the stability of flavonoids, carotenoids and vitamin A in broccoli and cauliflower inflorescences grown in an organic system. Results indicated that sous vide processing resulted in greater antioxidant capacity and that all processes contributed in some way to an increased content of antioxidant compounds in both cauliflower and broccoli.