Evaluation of the antioxidant potential of cauliflower (Brassica oleracea) from a glucosinolate content perspective

Pressurized liquid extraction of glucosinolates from Camelina sativa (L.) Crantz by-products: Process optimization and biological activities of green extract

The cultivation of Camelina sativa (L.) Crantz is rapidly increasing due to oil production resulting in a substantial volume of by-products, which still have an interesting composition in secondary metabolites, especially glucosinolates. Therefore, a green extraction procedure of glucosinolates by Pressurised Liquid Extraction was developed and optimized using a chemometric approach. Furthermore, the glucosinolates were purified by solid phase extraction, and a preliminary study on bioaccessibility and bioavailability study was carried out to evaluate the resistance of the glucosinolates to the digestive process. The application of pressurised liquid extraction to the recovery of glucosinolates from camelina sativa by-product, is a green, automatic, and rapid method, representing a valid alternative to conventional extraction method to obtain ingredients for food industries.

Development of White Cabbage, Coffee, and Red Onion Extracts as Natural Phosphodiesterase-4B (PDE4B) Inhibitors for Cognitive Dysfunction: In Vitro and In Silico Studies

Human cognition fundamentally depends on memory. Alzheimer's disease exhibits a strong correlation with a decline in this factor. Phosphodiesterase-4 B (PDE4B) plays a crucial role in neurodegenerative disorders, and its inhibition is one of the promising approaches for memory enhancement. This study aimed to identify secondary metabolites in white cabbage, coffee, and red onion extracts and identify their molecular interaction with PDE4B by in silico and in vitro experiments. Crushed white cabbage and red onion were macerated separately with ethanol to yield respective extracts, and ground coffee was boiled with water to produce aqueous extract. Thin layer chromatography (TLC)-densitometry was used to examine the phytochemicals present in white cabbage, coffee, and red onion extracts. Molecular docking studies were performed to know the interaction of test compounds with PDE4B. TLC-densitometry analysis showed that chlorogenic acid and quercetin were detected as major compounds in coffee and red onion extracts, respectively. In silico studies revealed that alpha-tocopherol (binding free energy (∆Gbind) = -38.00 kcal/mol) has the strongest interaction with PDE4B whereas chlorogenic acid (∆Gbind = -21.50 kcal/mol) and quercetin (∆Gbind = -17.25 kcal/mol) exhibited moderate interaction. In vitro assay showed that the combination extracts (cabbage, coffee, and red onion) had a stronger activity (half-maximal inhibitory concentration (IC50) = 0.12 ± 0.03 µM) than combination standards (sinigrin, chlorogenic acid, and quercetin) (IC50 = 0.17 ± 0.03 µM) and rolipram (IC50 = 0.15 ± 0.008 µM). Thus, the combination extracts are a promising cognitive enhancer by blocking PDE4B activity.

Chromosome-scale reference genome of broccoli (Brassica oleracea var. italica Plenck) provides insights into glucosinolate biosynthesis

Broccoli (Brassica oleracea var. italica Plenck) is an important vegetable crop, as it is rich in health-beneficial glucosinolates (GSLs). However, the genetic basis of the GSL diversity in Brassicaceae remains unclear. Here we report a chromosome-level genome assembly of broccoli generated using PacBio HiFi reads and Hi-C technology. The final genome assembly is 613.79 Mb in size, with a contig N50 of 14.70 Mb. The GSL profile and content analysis of different B. oleracea varieties, combined with a phylogenetic tree analysis, sequence alignment, and the construction of a 3D model of the methylthioalkylmalate synthase 1 (MAM1) protein, revealed that the gene copy number and amino acid sequence variation both contributed to the diversity of GSL biosynthesis in B. oleracea. The overexpression of BoMAM1 (BolI0108790) in broccoli resulted in high accumulation and a high ratio of C4-GSLs, demonstrating that BoMAM1 is the key enzyme in C4-GSL biosynthesis. These results provide valuable insights for future genetic studies and nutritive component applications of Brassica crops.

Assessment of Bio-Compounds Content, Antioxidant Activity, and Neuroprotective Effect of Red Cabbage (Brassica oleracea var. Capitata rubra) Processed by Convective Drying at Different Temperatures

Parkinson's disease (PD) is the second most common neurodegenerative disorder, and no efficient therapy able to cure or slow down PD is available. In this study, dehydrated red cabbage was evaluated as a novel source of bio-compounds with neuroprotective capacity. Convective drying was carried out at different temperatures. Total phenolics (TPC), flavonoids (TFC), anthocyanins (TAC), and glucosinolates (TGC) were determined using spectrophotometry, amino acid profile by LC-DAD and fatty acid profile by GC-FID. Phenolic characterization was determined by liquid chromatography-high-resolution mass spectrometry. Cytotoxicity and neuroprotection assays were evaluated in SH-SY5Y human cells, observing the effect on preformed fibrils of α-synuclein. Drying kinetic confirmed a shorter processing time with temperature increase. A high concentration of bio-compounds was observed, especially at 90 °C, with TPC = 1544.04 ± 11.4 mg GAE/100 g, TFC = 690.87 ± 4.0 mg QE/100 g and TGC = 5244.9 ± 260.2 µmol SngE/100 g. TAC degraded with temperature. Glutamic acid and arginine were predominant. Fatty acid profiles were relatively stable and were found to be mostly C18:3n3. The neochlorogenic acid was predominant. The extracts had no cytotoxicity and showed a neuroprotective effect at 24 h testing, which can extend in some cases to 48 h. The present findings underpin the use of red cabbage as a functional food ingredient.

Maximizing the value of indole-3-carbinol, from its distribution in dietary sources, health effects, metabolism, extraction, and analysis in food and biofluids

Indole-3-carbinol (I3C) is a major dietary component produced in Brassica vegetables from glucosinolates (GLS) upon herbivores' attack. The compound is gaining increasing interest due to its anticancer activity. However, reports about improving its level in plants or other sources are still rare. Unfortunately, I3C is unstable in acidic media and tends to polymerize rendering its extraction and detection challenging. This review presents a multifaceted overview of I3C regarding its natural occurrence, biosynthesis, isolation, and extraction procedure from dietary sources, and optimization for the best recovery yield. Further, an overview is presented on its metabolism and biotransformation inside the body to account for its health benefits and factors to ensure the best metabolic yield. Compile of the different analytical approaches for I3C analysis in dietary sources is presented for the first time, together with approaches for its detection and its metabolism in body fluids for proof of efficacy. Lastly, the chemopreventive effects of I3C and the underlying action mechanisms are summarized. Optimizing the yield and methods for the detection of I3C will assist for its incorporation as a nutraceutical or adjuvant in cancer treatment programs. Highlighting the complete biosynthetic pathway and factors involved in I3C production will aid for its future biotechnological production.

Relative evaluation of in-vitro antioxidant potential and phenolic constituents by HPLC-DAD of Brassica vegetables extracted in different solvents

Cabbage, cauliflower and broccoli are well-known vegetables from the Brassica family having functional effects on human health. This study was carried out to identify different antioxidant properties and to quantify phenolic compounds by HPLC-DAD in different extracts (methanol, ethanol and water: acetic acid: acetone) of these vegetables. The results showed that, the methanolic dry extract of cabbage possessed the highest antioxidant activity (549 ± 7.30 μg/g) and IC₅₀ was 90 ± 2.52 μg/mL than others. Whereas the ethanolic dry extract of cauliflower had 348 ± 5.20 μg/g of flavonoid, which was the highest among all. The maximum levels of total tannin (414 ± 5.20 μg/g) and total phenolic content (465 ± 3.25 μg/g) was found in broccoli dry extract. Several polyphenolic compounds were identified in different extracts of the vegetables and they were Cauliflower (8) > Cabbage (10) > Broccoli (9) in total. Therefore, the use of total vegetables rather than extracts in the food industry would be more appropriate to get greater health benefit.

Hairy Root Cultures as a Source of Polyphenolic Antioxidants: Flavonoids, Stilbenoids and Hydrolyzable Tannins

Due to their chemical properties and biological activity, antioxidants of plant origin have gained interest as valuable components of the human diet, potential food preservatives and additives, ingredients of cosmetics and factors implicated in tolerance mechanisms against environmental stress. Plant polyphenols are the most prominent and extensively studied, albeit not only group of, secondary plant (specialized) metabolites manifesting antioxidative activity. Because of their potential economic importance, the productive and renewable sources of the compounds are desirable. Over thirty years of research on hairy root cultures, as both producers of secondary plant metabolites and experimental systems to investigate plant biosynthetic pathways, brought about several spectacular achievements. The present review focuses on the Rhizobium rhizogenes-transformed roots that either may be efficient sources of plant-derived antioxidants or were used to elucidate some regulatory mechanisms responsible for the enhanced accumulation of antioxidants in plant tissues.

Selenium, Sulfur, and Methyl Jasmonate Treatments Improve the Accumulation of Lutein and Glucosinolates in Kale Sprouts

Kale sprouts contain health-promoting compounds that could be increased by applying plant nutrients or exogenous phytohormones during pre-harvest. The effects of selenium (Se), sulfur (S), and methyl jasmonate (MeJA) on lutein, glucosinolate, and phenolic accumulation were assessed in kale sprouts. Red Russian and Dwarf Green kale were chamber-grown using different treatment concentrations of Se (10, 20, 40 mg/L), S (30, 60, 120 mg/L), and MeJA (25, 50, 100 µM). Sprouts were harvested every 24 h for 7 days to identify and quantify phytochemicals. The highest lutein accumulation occurred 7 days after S 120 mg/L (178%) and Se 40 mg/L (199%) treatments in Red Russian and Dwarf Green kale sprouts, respectively. MeJA treatment decreased the level of most phenolic levels, except for kaempferol and quercetin, where increases were higher than 70% for both varieties when treated with MeJA 25 µM. The most effective treatment for glucosinolate accumulation was S 120 mg/L in the Red Russian kale variety at 7 days of germination, increasing glucoraphanin (262.4%), glucoerucin (510.8%), 4-methoxy-glucobrassicin (430.7%), and glucoiberin (1150%). Results show that kales treated with Se, S, and MeJA could be used as a functional food for fresh consumption or as raw materials for different industrial applications.

Salicornia ramosissima as a salt substitute in the fermentation of white cabbage

This research aimed to study the fermentation of white cabbage (Brassica oleracea) replacing salt, totally or partially, with halophyte Salicornia ramosissima, to reduce the sodium content in the final products. Three fermentation trials of cabbage were done: A with 2.91% salt (~ 1.15% Na) (control); B with salicornia (~ 1.56% salt equivalent, ~ 0.34% Na); and C with salt and salicornia (~ 1.94% salt equivalent, ~ 0.49% Na). The fermentation profile was followed by the physicochemical (pH, total acidity) and microbial parameters [mesophilic microorganisms (MM), lactic-acid bacteria (LAB), coliforms and fungi]. The content of phenolics and antioxidant activity in the fermented products were also measured. In all experiments, there was an increase, followed by a stabilization of the MM (5.5-7.2 Log CFU/g) and LAB populations (5.4-6.6 Log CFU/g) and a decrease of fungi and coliforms until they disappeared. A decrease in pH (< 4) and a rise in acidity (~ 1.0%) were observed throughout the fermentations. The phenolics and antioxidant activity increased during fermentation, being significantly higher in C (37.3 mg/100 g and 3.63 mmol Trolox/100 g, respectively). The fermentation of cabbage with salicornia results in the final products having similar microbial quality to the control, but with a reduction of sodium and an increase in the antioxidant activity.

The Metabolism of Glucosinolates by Gut Microbiota

Glucosinolates (GLS) and their derivatives are secondary plant metabolites abundant in Brassicaceae. Due to the enzymatic reaction between GLS and myrosinase enzyme, characteristic compounds with a pungent taste are formed, used by plants to defend themselves against insect herbivores. These GLS derivatives have an important impact on human health, including anti-inflammation and anti-cancer effects. However, GLS derivatives' formation needs previous enzymatic reactions catalyzed by myrosinase enzyme. Many of the brassica-based foods are processed at a high temperature that inactivates enzymes, hindering its bioavailability. In the last decade, several studies showed that the human gut microbiome can provide myrosinase activity that potentially can raise the beneficial effects of consumption of vegetables rich in GLS. The variability of the human gut microbiome (HGM) in human populations and the diverse intake of GLS through the diet may lead to greater variability of the real dose of pro-healthy compounds absorbed by the human body. The exploitation of the genetic and biochemical potential of HGM and correct ecological studies of both isolated strains and mixed population are of great interest. This review focuses on the most recent advances in this field.

Symmetrical Antioxidant and Antibacterial Properties of Four Romanian Cruciferous Extracts

Four alcoholic extracts from Romanian Cruciferous species—cabbage, acclimatized broccoli, black radish and cauliflower—were obtained in a microwave field. The extracts showed good and symmetric antioxidant activity (0.97–1.13 mmol/L TE) and good phenolic content (1001–1632 mg GAE/L). For the HPLC method, the limit of detection (LOD), limit of quantitation (LOQ) and recovery degree were established. The small values of LOD and LOQ indicated a great fit of data. The HPLC method achieved satisfactory quantitative recoveries in the range of 96%–122%, except for the lowest sinigrin concentration (8.774 µg/mL). The presence of metals in the studied extracts falls within the allowed limits. The four Cruciferous extracts showed good and slightly asymmetric antibacterial activities against some Gram-positive and Gram-negative bacteria, including strains with known resistance to antibiotics. Moreover, greater inhibitory effects were exhibited against Gram-negative bacteria. Asymmetrically, no inhibition was observed on the fungal strains. Therefore, the present results may suggest that some alcoholic extract formulas of cabbage and black radish (presenting good antibacterial activity) might be helpful in the antimicrobial fight and could be successfully used on selected cases and strains.

Assessing the risk of insecticides to Actinopterygii in the combination of ecological planting and rearing

In order to study the co-existing environment of pests and economic animals, the toxicity of 15 insecticides to Plutella xylostella, Monopterus albus, and Paramisgurnus dabryanus was tested. Combined with the recommended maximum doses in the field and bioassay, the results showed that for the three insecticides that were of relatively low toxicity to M. albus and P. dabryanus, spinetoram showed the best control effect on P. xylostella, followed by chlorfenapyr and chlorantraniliprole. However, P. xylostella showed a relatively high resistance to chlorfenapyr. Therefore, the best insecticide suitable for the fields with the cauliflower-finless eel or cauliflower-loach planting and rearing combination was spinetoram, followed by chlorantraniliprole and chlorfenapyr. Other insecticides such as emamectin benzoate, Bacillus thuringiensis (Bt), matrine, and so on were effective against the diamondback moth, but they were not suitable for use because of their high toxicity to the finless eel and loach.

Effects of Different Nitrogen Forms and Exogenous Application of Putrescine on Heat Stress of Cauliflower: Photosynthetic Gas Exchange, Mineral Concentration and Lipid Peroxidation

This study examines the effect of the exogenous application of polyamine putrescine together with the application of different ratios of nitrate/ammonium (NO₃⁻/NH₄⁺), on the physiology of cauliflower subjected to heat stress. The 50:50 NO₃⁻/NH₄⁺ ratio was the best ratio against heat stress. As a result of the joint application of these compounds, a higher photosynthetic rate, a higher accumulation of both photosynthesis-related compounds and pigments, total proteins, and a change in the status of nutrients were obtained. Particularly, the decrease in content of calcium, chloride and sulphate in plants under heat stress is ameliorated by the ammonium effect. Additionally, it is important to highlight that cauliflower waste contains a higher content of mineral nutrients than floret cauliflower. These effects were more marked in young leaves. Furthermore, a synergistic effect for coping with heat stress between the polyamine and the nutritional treatment was observed. For this, both the application of putrescine and the feeding of plants with a 50:50 NO₃⁻/NH₄⁺ ratio before heat stress is proposed for the first time as an agricultural practice for increasing the thermotolerance of cauliflower cv Moonshine. On the other hand, due to the lower lipid peroxidation rate obtained in cauliflower leaves, these plants could be used for health purposes as ointments or other nutraceutical products, making the cultivation of this kind of cruciferous more sustainable.

Phytochemical characterization, and antioxidant and antimicrobial activities of white cabbage extract on the quality and shelf life of raw beef during refrigerated storage

Brassica vegetables are well-characterized, containing a wide-spectrum of phenolic compounds that are responsible for their diverse biological activities like antioxidant and antimicrobial activities. This study explored the preservative effect of Brassica oleracea var. capitate f. alba (white cabbage; WC) on beef under refrigerated conditions for 16 days. The antimicrobial activities of WC were evaluated against foodborne pathogenic bacteria and fungi. The antioxidant activity was determined on the basis of total phenolic and flavonoid contents, through employing DPPH and ABTS assays. The chemical composition was analyzed by GC-MS analysis. The results indicated that among the different solvent extracts, white cabbage chloroform extract [WCCE] exhibited outstanding bioactive properties due to the presence of 4-nitro-3-(trifluoromethyl)phenol, and the effects of WCCE at different levels (A and B) on the quality and shelf life of beef in storage were evaluated. The color parameters (lightness, yellowness, and redness), texture analysis, and pH values were monitored constantly with 4 days interval, and microbial analysis was conducted. The results showed that WCCE-A treatment significantly reduced the total viable counts, psychrotrophic bacteria, and yeast-molds when compared with WCCE-B and control during refrigeration storage, with the activity varying in a dose-dependent manner (p < 0.05). Significantly, the WCCE-A treatments had better appearance compared with the control after 16 days of storage. All results confirmed that WCCE which is rich in bioactive compounds, effectively maintains the quality of beef compared to the control by retarding lipid oxidation and microbial growth at refrigeration temperature and also emphasize the potential applications of this plant in different industrial sectors.

Organosulfur Compounds: A Review of Their Anti-inflammatory Effects in Human Health

Phytonutrients are widely recognized for providing protective human health benefits. Among the phytonutrients, epidemiological and experimental studies show that dietary organosulfur compounds (OSC) play a significant role in preventing various human pathological progressions, including chronic inflammation, by decreasing inflammatory mediators such as nitric oxide (NO), prostaglandin (PG)E₂, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and IL-17, which are all typical hallmarks of inflammation. Evidence supports OSC in reducing the expression of these markers, thereby attenuating chronic inflammatory processes. Nuclear factor-kappa B (NF-κB) is a key regulating factor during inflammation, and novel evidence shows that OSC downregulates this transcriptional factor, thus contributing to the anti-inflammatory response. In vitro and in vivo studies show that inflammation is mechanistically linked with acute and chronic pathological conditions including cancer, diabetes, obesity, neural dysfunction, etc. Furthermore, a considerable number of experiments have demonstrated that the anti-inflammatory properties of OSC occur in a dose-dependent manner. These experiments also highlight indirect mechanisms as well as potent co-functions for protective roles as antioxidants, and in providing chemoprotection and neuroprotection. In this brief review, we provided an overview of the anti-inflammatory effects of OSC and elucidated probable mechanisms that are associated with inflammation and chronic disorders.

Nutritional Characterization of Two Rare Landraces of Turnip (Brassica rapa. var. rapa) Tops and Their On-Farm Conservation in Foggia Province

The study of nutritional properties in landrace products and the general context of its cultivation site are crucial to designing a sustainable on-farm strategy for landrace conservation. The present study describes the main nutritional aspects of two Brassica rapa subspecies rapa landraces collected in Puglia, Italy along with agroecological and socioeconomical traits where they are cultivated. The two B. rapa landraces (‘Cima di rapa dalla testa’ and ‘Cima di rapa antica’) are only found in sites at 700–800 m asl and in two landscape units (the Southern Daunian Mountains (SDM) and the Umbra Forest (UF), respectively) of the Foggia province. These rare landraces were selected by farmers to produce turnip greens/tops from ancient root turnip crops. They are named and consumed by local people in the same way as turnip tops of Brassica rapa subspecies sylvestris (‘Cima di rapa’), which are widely cultivated in Puglia. Compared to the most common ‘Cima di rapa’, the two highlighted landraces have a better nutritional profile linked to an improved content in antioxidant compounds—i.e., vitamin C (458 mg kg−1 FW), total phenols (347 mg ac. gallic equivalent kg−1 FW)—in glucosinolate (741 µmol kg FW−1, in ‘Cima di rapa antica’) and in minerals, such as K. Both landraces are deemed as having a high risk of erosion. Few exemplars are cultivated in marginal lands and urban/peri-urban areas (SDM), or in isolated sites within the UF, which is a special protection zone within Gargano National Park. However, natural, cultural, and recreational tourism are the main economic activities in both landscape units.

Differential partitioning of thiols and glucosinolates between shoot and root in Chinese cabbage upon excess zinc exposure

Zinc (Zn) is one of the important elements of plant growth, however, at elevated level it is toxic. Exposure of Chinese cabbage to elevated Zn²⁺ concentrations (5 and 10 μM ZnCl₂) resulted in enhancement of total sulfur and organic sulfur concentration. Transcript level of APS reductase (APR) as a key enzyme in biosynthesis of primary sulfur compounds (cysteine and thiols), was up-regulated in both shoot and root upon exposure to elevated Zn²⁺, which was accompanied by an increase in the concentration of cysteine in both tissues. In contrast, the concentration of thiols increased only in the root by 5.5 and 15-fold at 5 and 10 μM Zn²⁺, respectively, which was in accompanied by an upregulation of ATP sulfurylase, an enzyme responsible for activation of sulfate. An elevated content of glucosinolates, mostly indolic glucosinolates, only in the shoot of plants exposed to excess level of Zn²⁺ coincided with an increase in gene expression of key biosynthetic enzymes and regulators (CYP79B3, CYP83B1, MYB34). Thus distinct acuumulation patterns of sulfur containing compounds in root and shoot of Chinese cabbage may be a strategy for Chinese cabbage to combat with exposure to excess Zn.

Sulforaphane Protects Cells against Lipopolysaccharide-Stimulated Inflammation in Murine Macrophages

Inflammation is an essential part for the general or innate immune defenses to defend against tissue damage and accelerate the curing process by providing protection against pathogens. Sulforaphane (SFN) is a natural isothiocyanate that has potential properties against inflammation, along with other protective functions. The purpose of this study was to examine the mechanism of its protective effect on lipopolysaccharide (LPS)-induced inflammation in Raw 264.7 macrophages. Here, we compared LPS-challenged macrophages with or without SFN pretreatment. Macrophages were pre-incubated for 6 h with a wide range of concentrations of SFN (0 to 50 µM), and then treated with LPS for 24 h. Nitric oxide (NO) concentration and gene expression of different inflammatory mediators, i.e., interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β, were measured. SFN neither directly reacted with cytokines, nor with NO. To understand the mechanisms, we performed analyses of the expression of regulatory enzyme inducible nitic oxide synthase (iNOS), the transcription factor NF-E2-related factor 2 (Nrf2), and its enzyme heme-oxygenase (HO)-1. Our results revealed that LPS increased significantly the expression of inflammatory cytokines and concentration of NO in non-treated cells. SFN was able to prevent the expression of NO and cytokines through regulating inflammatory enzyme iNOS and activation of Nrf2/HO-1 signal transduction pathway.

Bioactive potential of fruit and vegetable wastes

Fruits and vegetables are essential for human nutrition, delivering a substantial proportion of vitamins, minerals, and fibers in our daily diet. Unfortunately, half the fruits and vegetables produced worldwide end up as wastes, generating environmental issues caused mainly by microbial degradation. Most wastes are generated by industrial processing, the so-called by-products. These by-products still contain many bioactive compounds post-processing, such as macronutrients (proteins and carbohydrates) and phytochemicals (polyphenols and carotenoids). Recently, the recovery of these bioactive compounds from industry by-products has received significant attention, mainly due to their possible health benefits for humans. This chapter focuses on the bioactive potential of fruit and vegetable by-products with possible applications in the food industry (functional foods) and in the health sector (nutraceuticals).

Effects of ozone and ammonium sulfate on cauliflower: Emphasis on the interaction between plants and insect herbivores

Ammonium sulfate [(NH₄)₂SO₄] deposition and elevated ozone (O₃) concentrations may negatively affect plants and trophic interactions. This study aimed to evaluate for the first time the interactive effects of high (NH₄)₂SO₄ load and elevated O₃ levels on cauliflower (Brassica oleracea L.) under field conditions. Cauliflower seedlings were treated with 0 (AS0) or 50 (AS50) kg ha^-1 (NH₄)₂SO₄ and exposed to ambient (AOZ, ≈20 ppb) or elevated (EOZ, ≈55 ppb) O₃ for about one month, in a Free Air O₃ Concentration Enrichment (FACE) system. The oligophagous diamondback moth (Plutella xylostella Linnaeus, 1758) showed a clear preference towards the seedlings treated with AS50, which intensively grazed. Plant-herbivore interactions were driven by (NH₄)₂SO₄ availability, rather than O₃, via increased nitrogen content in the leaves. Further laboratory bioassays were followed to confirm the validity of these observations using polyphagous Eri silkmoth larvae (Samia ricini) as a biological model in a standardized experimental setup. Choice assays, where larvae could select leaves among leaf samples from the different experimental conditions, and no-choice assays, where larvae could graze leaves from just one experimental condition, were conducted. In the choice assay, the larvae preferred AS50-treated leaves, in agreement with the field observations with diamondback moth. In the no-choice assay, larval body mass growth was inhibited when fed with leaves treated with EOZ and/or AS50. Larvae fed with AS50-treated leaves displayed increased mortality. These observations coincide with higher NO₃ and Zn content in AS50-treated leaves. This study shows that plant-herbivore interactions can be driven by (NH₄)₂SO₄ availability, independently of O₃, and suggests that high N deposition may have severe health implications in animals consuming such plant tissues. Key message: Plant-herbivore interactions are driven by high (NH₄)₂SO₄ availability, independently of O₃.

ω-Methylsulfanylalkyl Glucosinolates: A General Synthetic Pathway

A general pathway was devised to synthesize ω-methylsulfanylalkyl glucosinolates, which represent an important class of structurally homogeneous plant secondary metabolites. The required thiofunctionalized hydroximoyl chlorides were obtained from the corresponding α,ω-nitroalkyl methylsulfide precursors, involving as the key-step, a nitronate chlorination strategy. A coupling reaction with 1-thio-beta-d-glucopyranose, followed by O-sulfation of the intermediate thiohydroximate and final deprotection of the sugar moiety afforded the target compounds.

Nrf2 targeting by sulforaphane: A potential therapy for cancer treatment

In the past decades, extensive studies have reported the potential chemopreventive activity of sulforaphane, an isothiocyanate derived from glucoraphanin, occurring in large amounts in Brassica genus plants. Sulforaphane was found to be active against several forms of cancer. A growing body of data shows that sulforaphane acts against cancer at different levels, from development to progression, through pleiotropic effects. In this review, we discuss the available experimental and clinical data on the potential therapeutic role of sulforaphane against cancer. Its effects range from the protection of cells from DNA damage to the modulation of the cell cycle via pro-apoptotic, anti-angiogenesis and anti-metastasis activities. At molecular level, sulforaphane modulates cellular homeostasis via the activation of the transcription factor Nrf2. Although data from clinical studies are limited, sulforaphane remains a good candidate in the adjuvant therapy based on natural molecules against several types of cancer.

Antioxidant and anti-inflammatory effects of cauliflower leaf powder-enriched diet against LPS induced toxicity in rabbits

Brassicaphytochemicals exert a broad spectrum of health-promoting activities.

Exogenous Methyl Jasmonate and Salicylic Acid Induce Subspecies-Specific Patterns of Glucosinolate Accumulation and Gene Expression in Brassica oleracea L

Glucosinolates have anti-carcinogenic properties. In the recent decades, the genetics of glucosinolate biosynthesis has been widely studied, however, the expression of specific genes involved in glucosinolate biosynthesis under exogenous phytohormone treatment has not been explored at the subspecies level in Brassica oleracea. Such data are vital for strategies aimed at selective exploitation of glucosinolate profiles. This study quantified the expression of 38 glucosinolate biosynthesis-related genes in three B. oleracea subspecies, namely cabbage, broccoli and kale, and catalogued associations between gene expression and increased contents of individual glucosinolates under methyl jasmonate (MeJA) and salicylic acid (SA) treatments. Glucosinolate accumulation and gene expression in response to phytohormone elicitation was subspecies specific. For instance, cabbage leaves showed enhanced accumulation of the aliphatic glucoiberin, progoitrin, sinigrin and indolic neoglucobrassicin under both MeJA and SA treatment. MeJA treatment induced strikingly higher accumulation of glucobrassicin (GBS) in cabbage and kale and of neoglucobrassicin (NGBS) in broccoli compared to controls. Notably higher expression of ST5a (Bol026200), CYP81F1 (Bol028913, Bol028914) and CYP81F4 genes was associated with significantly higher GBS accumulation under MeJA treatment compared to controls in all three subspecies. CYP81F4 genes, trans-activated by MYB34 genes, were expressed at remarkably high levels in all three subspecies under MeJA treatment, which also induced in higher indolic NGBS accumulation in all three subspecies. Remarkably higher expression of MYB28 (Bol036286), ST5b, ST5c, AOP2, FMOGS-OX5 (Bol031350) and GSL-OH (Bol033373) was associated with much higher contents of aliphatic glucosinolates in kale leaves compared to the other two subspecies. The genes expressed highly could be utilized in strategies to selectively increase glucosinolate compounds in B. oleracea subspecies. These results promote efforts to develop genotypes of B. oleracea and other species with enhanced levels of desired glucosinolates.

3-Butenyl isothiocyanate: a hydrolytic product of glucosinolate as a potential cytotoxic agent against human cancer cell lines

The present study envisages the cytotoxic potential of 3-butenyl isothiocyanate isolated from Brassica juncea L. Czern var. Pusa Jaikisan against the human cancer cell lines viz. prostate, bone osteosarcoma, cervical, liver, neuroblastoma and breast cancer. As the compound was observed to be more effective against prostate cancer cell line, therefore, this cell line was further used to study the mechanism of cell death using neutral red assay, reactive oxygen species assay, mitochondrial membrane potential assay, microscopic and cell cycle analysis. The mechanistic analysis indicated that it induced the cell death of prostate cancer cells via apoptosis and hence made it an excellent choice as an effective anticancer compound.

Antigenotoxicity and Tumor Growing Inhibition by Leafy Brassica carinata and Sinigrin

Cruciferous vegetables are well known and worldwide consumed due to their health benefits and cancer prevention properties. As a desirable cruciferous plant, Ethiopian mustard (Brassica carinata A. Braun) and its glucosinolate sinigrin were tested in the in vivo Drosophila melanogaster (SMART) and the in vitro HL60 (human promyelocytic leukaemia cell line) systems. High performance liquid chromatography (HPLC) analysis of plant samples confirmed the presence of sinigrin as principal B. carinata glucosinolate. SMART was performed by feeding D. melanogaster larvae either with different concentrations of plant/compound samples or combining them with hydrogen peroxide (a potent oxidative mutagen) being both antimutagenics. HL60 assays showed the tumoricidal activity of plant samples (IC₅₀ = 0.28 mg·mL⁻¹) and the breakdown products of sinigrin hydrolysis (IC₅₀ = 2.71 µM). Our results enhance the potential of B. carinata as health promoter and chemopreventive in both systems and the leading role of sinigrin in these effects.

Optimisation of ultrasound-assisted extraction of natural antioxidants from mustard seed cultivars

BACKGROUND

Modified mustard varieties can produce edible oil with reduced amounts of erucic acid and glucosinolates and enhanced antioxidant potential. Therefore, this work focused on the optimisation of the ultrasound-assisted extraction of compounds with high antioxidant capacity from three white mustard seed cultivars using response surface methodology.

RESULTS

The predicted optimum solvent polarity (57.2, 56.5 and 57.6) and ultrasound power-to-sonication time ratio (4.5, 4.8 and 4.3 W min(-1)) resulted in antioxidant capacities determined by the ferric-reducing antioxidant power (FRAP) assay [54.37, 65.75 and 68.55 mmol Trolox equivalent (TE) kg(-1)] and the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) method (141.65, 175.26 and 185.10 mmol TE kg(-1)) and total phenolics content (23.70, 27.16 and 11.29 mg sinapic acid g(-1)) for extracts obtained from one traditional and two modified mustard seed varieties. The highest FRAP and DPPH values (69.51 and 197.73 mmol TE kg(-1)) revealed 50% methanolic extract prepared from modified mustard seed cultivar without erucic acid and glucosinolates treated with ultrasound for 30 min (ultrasound power/ultrasound time = 4 W min(-1)).

CONCLUSION

Ultrasound-assisted extraction was found to be a more rapid, convenient and appropriate extraction method with higher yield of antioxidants, shorter time and lower solvent consumption in comparison to conventional extraction.

Antimicrobial potential of cauliflower, broccoli, and okara byproducts against foodborne bacteria

The antimicrobial potential of cauliflower, broccoli, and okara byproducts was assessed against Gram-positive and Gram-negative bacteria. Salmonella enterica serovar Typhimurium, Escherichia coli O157:H7, Bacillus cereus, and Listeria monocytogenes serovar 4b growth behavior was assessed under exposure to 5% vegetable byproducts added to the reference medium, buffered peptone water (0.1% [wt/vol]), at 37°C. Although the byproducts were not effective against L. monocytogenes, they were bactericidal against Salmonella Typhimurium, E. coli O157:H7, and B. cereus. The most promising results were achieved with the cauliflower-Salmonella Typhimurium combination, because the bacterial population was reduced by 3.11 log10 cycles after 10 h of incubation at 37°C as a result of 5% cauliflower addition. Further studies were carried out for this combination, at different cauliflower concentrations (0, 0.5, 1, 5, 10, and 15%) and at temperatures in the range of 5-37°C. The greatest inactivation level (6.11 log10 cycles) was achieved at refrigeration temperature (5°C) using 15% cauliflower addition. Both temperature and cauliflower concentration significantly (p≤0.05) influenced the Salmonella Typhimurium inactivation level. The kinetic parameters were adjusted to mathematical models. The modified Gompertz mathematical model provided an accurate fit (root-mean-square error (RMSE) [0.00009-0.21] and adjusted-R(2) [0.81-0.99]) to experimental Salmonella Typhimurium survival curves describing inactivation kinetics of the pathogen to the antimicrobial effect of cauliflower byproduct.

Enzyme-assisted extraction enhancing the phenolic release from cauliflower (Brassica oleracea L. var. botrytis) outer leaves

Phenolic compounds are highly present in byproducts from the cauliflower (Brassica oleracea L. var. botrytis) harvest and are thus a valuable source for valorization toward phenolic-rich extracts. In this study, we aimed to optimize and characterize the release of individual phenolic compounds from outer leaves of cauliflower, using two commercially available polysaccharide-degrading enzymes, Viscozyme L and Rapidase. As major results, the optimal conditions for the enzyme treatment were: enzyme/substrate ratio of 0.2% for Viscozyme L and 0.5% for Rapidase, temperature 35 °C, and pH 4.0. Using a UPLC-HD-TOF-MS setup, the main phenolic compounds in the extracts were identified as kaempferol glycosides and their combinations with different hydroxycinnamic acids. The most abundant components were kaempferol-3-feruloyldiglucoside and kaempferol-3-glucoside (respectively, 37.8 and 58.4 mg rutin equiv/100 g dry weight). Incubation of the cauliflower outer leaves with the enzyme mixtures resulted in a significantly higher extraction yield of kaempferol-glucosides as compared to the control treatment.

Impact of selenium supply on Se-methylselenocysteine and glucosinolate accumulation in selenium-biofortified Brassica sprouts

Brassica sprouts are widely marketed as functional foods. Here we examined the effects of Se treatment on the accumulation of anticancer compound Se-methylselenocysteine (SeMSCys) and glucosinolates in Brassica sprouts. Cultivars from the six most extensively consumed Brassica vegetables (broccoli, cauliflower, green cabbage, Chinese cabbage, kale, and Brussels sprouts) were used. We found that Se-biofortified Brassica sprouts all were able to synthesize significant amounts of SeMSCys. Analysis of glucosinolate profiles revealed that each Brassica crop accumulated different types and amounts of glucosinolates. Cauliflower sprouts had high total glucosinolate content. Broccoli sprouts contained high levels of glucoraphanin, a precursor for potent anticancer compound. Although studies have reported an inverse relationship between accumulation of Se and glucosinolates in mature Brassica plants, Se supply generally did not affect glucosinolate accumulation in Brassica sprouts. Thus, Brassica vegetable sprouts can be biofortified with Se for the accumulation of SeMSCys without negative effects on chemopreventive glucosinolate contents.

Glucosinolates redox activities: can they act as antioxidants?

Glucosinolates are a class of secondary plant metabolites particularly occurring in Cruciferae with potential health-promoting properties, as their hydrolysis products, isothiocyanates, possess chemopreventive and antioxidant activities. In the present study, we systematically studied the in vitro redox behaviour of 15 glucosinolates, by using a range of analytical methods measuring different activities: (i) radical scavenging activity toward peroxyl and toward ABTS radical (chain-breaking activity); (ii) capacity in modulating the in vitro resistance of human low-density lipoprotein (LDL) catalysed by copper (chelating and chain-breaking activity). Data obtained from different assays were compared and analysed by principal component analysis (PCA). PCA allowed us to identify a big cluster of glucosinolates (10 out 15 tested) that do not possess any antioxidant capacity; while, the other five glucosinolates showed moderate and specific antioxidant capacity. Notably, sinalbin and gluconasturtiin were highly active in scavenging ABTS radical and in protecting LDL from copper-catalysed oxidation, respectively. The overall results of this study indicate that just few glucosinolates can act as antioxidants.

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.

Review on Cardamine diphylla (Michx.) A. wood (Brassicaceae): ethnobotany and glucosinolate chemistry

ETHNOPHARMACOLOGICAL RELEVANCE

Cardamine diphylla (Michx.) A. Wood, commonly called toothwort, is a spring perennial herb belonging to the Brassicaceae family. This endemic plant of Eastern North America has been widely used by multiple American First Nations (i.e. indigenous people of North America) for food and medicine for centuries.

APPROACH AND METHODS

The aim of the review is to describe the botany, ethnopharmacology, phytochemistry, and bioactivity of Cardamine diphylla. The review covers literature on Cardamine diphylla, and the alternative name Dentaria diphylla, from English and French language sources.

RESULTS

Multiple traditional uses of Cardamine diphylla by American First Nations are well documented. Initial health studies showed that the tested concentrations of the extract were not toxic against brine shrimp larvae and the same extract had a weak free-radical scavenging activity. However, bioactive compounds in the form of aliphatic and indole glucosinolates and some indole alkaloids have been isolated from this plant. Ecological research regarding Cardamine diphylla-insect interactions (such as feeding and oviposition) is also available in the literature.

CONCLUSIONS

The wide range of traditional uses by multiple American First Nations suggests that the antibacterial, antiviral, immunostimulant, analgesic, antipyretic, and anti-inflammatory activities of this plant should be explored in in vitro and in vivo tests. Traditional modes of preparation of the plant suggest that some of the medicinal properties could certainly be attributed to glucosinolate degradation products (i.e. isothiocyanates), but a clear assignment of active molecules and mechanisms of action remain to be elucidated. The presence of glucosinolates indicates that the plant could be probed for cancer chemopreventive properties. Overall, the review shows that more investigation is necessary to determine the possible benefits of Cardamine diphylla extracts to pharmaceutical companies as a nutraceutic specialty phytotherapeutic agent against respiratory (cold and sore throat) or gastrointestinal problems.

Glucosinolates profile and antioxidant capacity of Romanian Brassica vegetables obtained by organic and conventional agricultural practices

The profile of glucosinolates in relation to the antioxidant capacity of five Brassica vegetables (Broccoli, Cauliflower, Kohlrabi, White and Red Cabbage) grown by organic and conventional agricultural practices in Transylvania region-Romania, were determined and compared. The qualitative and quantitative compositions of glucosinolates were determined by HPLC-PDA technique. The antioxidant capacity was comparatively determined by ABTS, DPPH, FRAP and Folin-Ciocalteu assays. The highest glucosinolates levels were found in the Broccoli samples grown under conventional practices (14.24 μmol/g dry weight), glucoraphanin, glucobrassicin and neo-glucobrassicin being the major components. The total glucosinolates content was similar in Kohlrabi and Cauliflower (4.89 and 4.84 μmol/g dry weight, respectively), the indolyl glucosinolates were predominant in Kohlrabi, while the aliphatic derivatives (sinigrin and glucoiberin) were major in Cauliflower. In Cabbage samples, the aliphatic glucosinolates were predominat against indolyl derivatives, glucoraphanin and glucoiberin being the main ones in Red Cabbage. The principal component analysis was applied to discriminate among conventional and organic samples and demonstrated non-overlaps between these two agricultural practices. Meanwhile it was shown that glucosinolates may represent appropriate molecular markers of Brassica vegetables, their antioxidant capacity being higher in organic crops, without significant differences among different Brassica varieties.

Evaluation of the effect of hydroxypropyl-β-cyclodextrin on topical administration of milk thistle extract

Two water in oil emulsions composed by eudermic ingredients as glycerin, cocoa butter, almond oil and a variety of lipids, were enriched respectively with milk thistle dry extract (MT) or with a binary complex composed by MT and hydroxypropyl-β-cyclodextrin (HP) (1:4 w/w) correspondent to 1% (w/w) in sylimarine in order to obtain two different emulsions designed for the skin delivery and determine influence of hydroxypropyl-β-cyclodextrin on the extract delivery and permeation. Uv-vis spectrophotometric analyses demonstrated that phytocomplex formation influences the finding of MT after the complexation process and the in vitro antioxidant activity. Further in vitro and ex vivo experiments demonstrated that the penetration capability of MT from formulations is strictly influenced by the phytocomplex able to control MT permeation; moreover phytocomplex increases flavonoids stability during the in vitro tests. Additionally, in vivo studies showed that the penetration into the stratum corneum of the active ingredients is effectively achieved by the phytocomplex formation, in fact about 80% of MT is absorbed by the skin along 1h despite the 30% of MT not complexed absorbed during the same period.