Sustainable Use of Bioactive Compounds from Solanum Tuberosum and Brassicaceae Wastes and by-Products for Crop Protection-A Review.

Defatted seed meals of oleaginous Brassicaceae, such as Eruca sativa, and potato peel are excellent plant matrices to recover potentially useful biomolecules from industrial processes in a circular strategy perspective aiming at crop protection. These biomolecules, mainly glycoalkaloids and phenols for potato and glucosinolates for Brassicaceae, have been proven to be effective against microbes, fungi, nematodes, insects, and even parasitic plants. Their role in plant protection is overviewed, together with the molecular basis of their synthesis in plant, and the description of their mechanisms of action. Possible genetic and biotechnological strategies are presented to increase their content in plants. Genetic mapping and identification of closely linked molecular markers are useful to identify the loci/genes responsible for their accumulation and transfer them to elite cultivars in breeding programs. Biotechnological approaches can be used to modify their allelic sequence and enhance the accumulation of the bioactive compounds. How the global challenges, such as reducing agri-food waste and increasing sustainability and food safety, could be addressed through bioprotector applications are discussed here.

Phytochemical Characterization and In Vitro Antioxidant Properties of Four Brassica Wild Species from Italy.

In the present study, we evaluated for the first time the variability of antioxidant traits of four Brassica wild species: B. incana, B. macrocarpa, B. villosa, and B. rupestris. The content of the main water-soluble antioxidants (phenolics, ascorbic acid, and total biothiols) and the in vitro antioxidant potential (1,1-diphenyl-2-picrylhydrazil (DPPH) and superoxide anion scavenging capacity) were investigated. A total of 28 polyphenolic compounds were identified by LC/MS and quantitated by HPLC/DAD analysis. Kaempferol and quercetin derivatives were the most abundant phenolics compared to hydroxycinnamoyl gentiobiosides. In the ten populations, phenolics ranged from 163.9 to 533.9 mg/100 g dry weight (d.w.), ascorbic acid from 7.6 to 375.8 mg/100 g d.w., and total biothiols from 0.59 to 5.13 mg/100 g d.w. The different classes of phytochemicals were separated using solid-phase extraction at increasing methanol concentrations, and the antioxidant power of fractionated extracts was evaluated. The superoxide anion scavenging activity was significantly correlated to phenolics, particularly to flavonol derivatives, while DPPH was mainly related to ascorbic acid content. The present findings improve the knowledge of the phytochemical composition of Italian Brassica wild species by showing the great diversity of phytochemicals among populations and highlighting their importance as a valuable genetic resource for developing new cultivars with improved bioactive content.

Influence of drying techniques and growing location on the chemical composition of sweet pepper (Capsicum annuum L., var. Senise).

The aim of this work was the comprehensive characterization of dried Senise pepper, a tasty landrace, to verify the suitability of common industrial processing and different growing locations to its production. Fruits from experimental CREA fields of Battipaglia (southern Italy) and Montanaso (northern Italy), dried using a solar dryer or a forced air oven, were compared with lyophilized and commercial samples. Solar dried samples showed a retention of glucose, while fructose levels decreased. Citric acid was the main acid in all samples, showing a differentiated behavior upon processing, with higher content in Battipaglia samples. The ascorbic acid showed the highest correlation with antioxidant assays, and both drying methods decreased its content, with better retention in Battipaglia samples. Drying did not markedly affect carotenoid levels, showing higher content in Battipaglia peppers. Both drying technique and mostly growing location influenced the volatile profile, with higher apocarotenoid content in Battipaglia samples. PRACTICAL APPLICATIONS: The use of Senise red pepper, a tasty landrace awarded in 1996 with the PGI certification mark, is spreading even outside Italy due to the renewed interest for high quality products with excellent taste and healthy properties. These peppers are mostly sun-dried following a traditional procedure and consumed as spice. New approaches regarding the type of drying and the growing location of this spice, together with the knowledge about the changes in quality indexes with processing, can be useful for a better exploitation of this product, increasing its market availability and lowering the cost of production.

Impact of year of harvest, genotype and cultivation method on bioactives and Pru d 1 allergen content in plums.

The present work studied the effect of the year of harvest, the genotype and the cultivation method on the nutritional quality and the allergen content of three plum cultivars. The common quality parameters and the phytochemical content strongly varied with the year and the cultivar, while the system of cultivation had a minor influence. In particular, ascorbic acid greatly decreased in 2016 compared to 2015, while polyphenols were higher in 2016. The health-promoting compounds, and particularly phenolics, were significantly correlated with the antioxidant capacity. Finally, the allergen content was strongly dependent on the content of flavan-3-ols, suggesting that this class of phenolics is determinant in influencing the allergen content in plums. Results showed that the major factor affecting the quality and the concentration of natural metabolites of plum, in addition to the diversity among genotypes, is the year-to-year variation, whereas the system of cultivation plays a marginal role.

Phenolic Content and Antioxidant Activity in Trifolium Germplasm from Different Environments.

Phenolics are important mediators in plant-environment interactions. The presence and concentration of phenolic compounds and their antioxidant activity were evaluated in leaves and flowers of a set of Trifolium species originating from contrasting environments encompassing lowland and mountain sites. The current germplasm proved a great reservoir of phenolic compounds, with different chemical structure and, possibly, diversified biological activity. Germplasm groups with specific phenolic composition were observed. In some cases, different patterns bore a taxonomic meaning. Lowland germplasm showed higher concentration of total phenolics in leaves than mountain accessions (50.30 vs. 34.19 mg/g dry matter (DM)), while the latter had higher concentration in flowers (114.16 vs. 57.44 mg/g DM). Outstanding concentration of isoflavones was observed in leaves of lowland germplasm (24.19 mg/g DM), and of both proanthocyanidins and flavonoids in flowers of mountain germplasm (53.81 and 56.62 mg/g DM, respectively). The pattern of phenolic composition in lowland and mountain germplasm was suggestive of different adaptive strategies. Three assays of antioxidant activity were tested, which were characterised by rather different reactivity towards phenolic composition. The scavenging activity was higher for leaf extracts of lowland germplasm, and for flower extracts of mountain germplasm. Besides identifying germplasm of interest, this study also suggested possible links between environmental factors and concentration and composition of phenolic compounds.

Potential of delphinidin-3-rutinoside extracted from Solanum melongena L. as promoter of osteoblastic MC3T3-E1 function and antagonist of oxidative damage.

PURPOSE: Increasing evidence suggests the potential use of natural antioxidant compounds in the prevention/treatment of osteoporosis. This study was undertaken to investigate the effects of purified delphinidin-3-rutinoside (D3R), isolated from Solanum melongena L., on osteoblast viability and differentiation in basal conditions and its ability to protect MC3T3-E1 cells against oxidative damage induced by tert-butyl hydroperoxide (t-BHP). METHODS: MC3T3-E1 osteoblastic cells were treated with D3R (10-11-10-5 M for 24 h), followed by treatment with t-BHP (250 µM for 3 h). To test cell viability, MTT test was performed. Apoptotic cells were stained with Hoechst-33258 dye. Cytoskeleton rearrangement was stained with FICT-labelled phalloidin. Intracellular ROS production was measured using dichlorofluorescein CM-DCFA. The reduced glutathione to oxidized glutathione ratio (GSH/GSSG) contents was measured according to the OPT fluorimetric assay. RESULTS: D3R (10-9 M) significantly increases viability of MC3T3-E1 cells and promotes osteoblast differentiation by increasing the expression of type I collagen, alkaline phosphatase and osteocalcin. Pre-treatment with D3R (10-9 M) significantly prevented t-BHP-induced osteoblastic dysfunction and changes in the cytoskeleton organization by decreasing intracellular ROS and preventing the reduction in GSH/GSSG. D3R did not significantly modify the expression of Osteoprotegerin/RANKL system activated by t-BHP suggesting a lack of effect of D3R on osteoblast/osteoclast crosstalk. D3R protective effects against t-BHP-induced osteoblastic dysfunction were mediated by the PI3K/Akt pathway since they were completely prevented by LY294002, a PI3K/Akt specific inhibitor. CONCLUSIONS: These findings indicate that D3R protects MC3T3-E1 cells from oxidative damage and suggest the potential utility of dietary D3R supplement to prevent osteoblast dysfunction in age-related osteoporosis.

A Polyphenol Rich Extract from Solanum melongena L. DR2 Peel Exhibits Antioxidant Properties and Anti-Herpes Simplex Virus Type 1 Activity In Vitro.

DR2B and DR2C extracts, obtained by ethanolic maceration of peel from commercially and physiologically ripe aubergine berries, were studied for the antioxidative cytoprotective properties and anti-HSV-1 activity, in line with the evidence that several antioxidants can impair viral replication by maintaining reducing conditions in host cells. The antioxidative cytoprotective effects against tBOOH-induced damage were assessed in Caco2 cells, while antiviral activity was studied in Vero cells; polyphenolic fingerprints were characterized by integrated phytochemical methods. Results highlighted different compositions of the extracts, with chlorogenic acid and delphinidin-3-rutinoside as the major constituents; other peculiar phytochemicals were also identified. Both samples reduced reactive oxygen species (ROS) production and exhibited scavenging and chelating properties. DR2C partly counteracted the tBOOH-induced cytotoxicity, with a remarkable lowering of lactate metabolism under both normoxia and hypoxia; interestingly, it increased intracellular GSH levels. Furthermore, DR2C inhibited the HSV-1 replication when added for 24 h after viral adsorption, as also confirmed by the reduction of many viral proteins' expression. Since DR2C was able to reduce NOX4 expression during HSV-1 infection, its antiviral activity may be correlated to its antioxidant properties. Although further studies are needed to better characterize DR2C activity, the results suggest this extract as a promising new anti-HSV-1 agent.

Effect of the Strawberry Genotype, Cultivation and Processing on the Fra a 1 Allergen Content.

Birch pollen allergic patients show cross-reactivity to vegetables and fruits, including strawberries (Fragaria × ananassa). The objective of this study was to quantify the level of the Fra a 1 protein, a Bet v 1-homologous protein in strawberry fruits by a newly developed ELISA, and determine the effect of genotype, cultivation and food processing on the allergen amount. An indirect competitive ELISA using a specific polyclonal anti-Fra a 1.02 antibody was established and revealed high variability in Fra a 1 levels within 20 different genotypes ranging from 0.67 to 3.97 µg/g fresh weight. Mature fruits of red-, white- and yellow-fruited strawberry cultivars showed similar Fra a 1 concentrations. Compared to fresh strawberries, oven and solar-dried fruits contained slightly lower levels due to thermal treatment during processing. SDS-PAGE and Western blot analysis demonstrated degradation of recombinant Fra a 1.02 after prolonged (>10 min) thermal treatment at 99 °C. In conclusion, the genotype strongly determined the Fra a 1 quantity in strawberries and the color of the mature fruits does not relate to the amount of the PR10-protein. Cultivation conditions (organic and conventional farming) do not affect the Fra a 1 level, and seasonal effects were minor.

Variations in the phytochemical contents and antioxidant capacity of organically and conventionally grown Italian cauliflower (Brassica oleracea L. subsp. botrytis): results from a three-year field study.

A three-year field study (2009-2011) was performed to evaluate phytochemicals and antioxidant capacities of two genotypes (HF1 Emeraude and the local variety, Velox) of green cauliflower grown under organic and conventional management. The conventional system increased yield, but had little effect on the dry matter, whereas the organic system increased the soluble solids. Phytochemicals and antioxidant capacity showed significant year-to-year variability. During the third year, the scarce rainfall determined a significant increase of total glucosinolates and a general decrease of antioxidants in all samples. Interestingly, in the same year organic plants were less affected by the unfavorable climatic conditions, as they increased ascorbic acid, polyphenols, and carotenoids with respect to conventional ones. The overall results for the three years showed that the two genotypes responded differently. Compared to the conventional system, Velox showed 24, 21, 13, 48, and 44% higher content of ascorbic acid, polyphenols, carotenoids, volatiles, and antioxidant capacity, respectively. In contrast, no significant increase in the phytochemicals or the antioxidant potential was found in organic Emeraude, with the exception of total volatiles (+41%). These findings suggest that organic cultivation may be highly effective for particular cauliflower genotypes.

Characterization of health-related compounds in eggplant (Solanum melongena L.) lines derived from introgression of allied species.

The purpose of the present study was to investigate the levels of either the nutraceutical and health-promoting compounds or the antioxidant properties of innovative eggplant (Solanum melongena L.) genotypes tolerant and/or resistant to fungi, derived from conventional and non-conventional breeding methodologies (i.e., sexual interspecific hybridization, interspecific protoplast electrofusion, androgenesis, and backcross cycles) in comparison with their allied and cultivated parents. Chemical measures of soluble refractometric residue (SRR), glycoalkaloids (solamargine and solasonine), chlorogenic acid (CA), delphinidin 3-rutinoside (D3R), total phenols (TP), polyphenoloxidase (PPO) activity, antiradical activity on superoxide anion and hydroxyl radical were carried out in raw fruit and peel of 57 eggplant advanced introgression lines (ILs), of three eggplant recurrent genotypes and of three allied species during 2005 and 2006. The majority of the ILs, obtained after several backcross cycles, showed positive characteristics with respect to the allied parents such as good levels of SRR, CA, D3R, TP, PPO activity, the scavenging activity against superoxide anion and hydroxyl radical and, in particular, significantly (p

Thermal treatment of eggplant (Solanum melongena L.) increases the antioxidant content and the inhibitory effect on human neutrophil burst.

The aim of this study was to compare the amount and activity of phytonutrients in raw, grilled, and boiled eggplant fruit using chemical measures and a biological assay of oxidative bursts in human neutrophils. The thermally treated samples showed various changes in their chemical composition (dry matter, soluble solids, acidity, and the amount of alcohol insoluble substances) due to the cooking processes and were much richer in the main phenolic compounds such as chlorogenic and caffeic acids, which are known to be antioxidants. Consequently, their free radical scavenging activity was significantly higher, especially that of superoxide anion. The biological assay of oxidative bursts from human neutrophils in the presence of N-formyl-methionyl-leucyl-phenylalanine confirmed the greater activity of extracts of the cooked eggplants with respect to raw eggplants. Successive extract dilutions showed a significant activity up to 1.25 microg/mL after cooking, while raw fruits resulted in an activity up to 10.00 microg/mL. These results showed that the thermal treatment commonly used before consumption can increase the content and biological activity of antioxidant compounds of eggplants.

Antioxidant activity of Calendula officinalis extract: inhibitory effects on chemiluminescence of human neutrophil bursts and electron paramagnetic resonance spectroscopy.

There is growing interest in natural chemical compounds from aromatic, spicy, medicinal and other plants with antioxidant properties in order to find new sources of compounds inactivating free radicals generated by metabolic pathways within body tissue and cells, mainly polymorphonuclear leukocytes (PMNs) whose overregulated recruitment and activation generate a large amount of reactive oxygen species (ROS) and reactive nitrogen species (RNS), leading to an imbalance of redox homeostasis and oxidative stress. The aim of this study was to examine whether a propylene glycol extract of Calendula officinalis interferes with ROS and RNS during the PMN respiratory bursts, and to establish the lowest concentration at which it still exerts antioxidant activity by means of luminol-amplified chemiluminescence. Electron paramagnetic resonance (EPR) spectroscopy was also used in order to confirm the activity of the C. officinalis extract. The C. officinalis extract exerted its anti-ROS and anti-RNS activity in a concentration-dependent manner, with significant effects being observed at even very low concentrations: 0.20 microg/ml without L-arginine, 0.10 microg/ml when L-arginine was added to the test with phorbol 12-myristate 13-acetate and 0.05 microg/ml when it was added to the test with N-formyl-methionyl-leucyl-phenylalanine. The EPR study confirmed these findings, 0.20 microg/ml being the lowest concentration of C. officinalis extract that significantly reduced 2,2-diphenyl-1-picrylhydrazyl. These findings are interesting for improving the antioxidant network and restoring the redox balance in human cells with plant-derived molecules as well as extending the possibility of antagonizing the oxidative stress generated in living organisms when the balance is in favor of free radicals as a result of the depletion of cell antioxidants.