Simultaneous identification of glucosinolates and phenolic compounds in a representative collection of vegetable Brassica rapa

Assessment of the effect of drying on Brassica greens via a multiplex approach based on LC-QTOF-MS/MS, molecular networking, and chemometrics along with their antioxidant and anticancer activities

Turnip (Brassica rapa var rapa L.) leaves are a rich source of versatile bioactive phytochemicals with great potential in the food and herbal industries. However, the effect of drying on its constituents has never been studied before. Hereto, three drying techniques were compared, namely, lyophilization (LY), vacuum oven (VO), and shade drying (SD). Chemical profiling utilizing liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-QTOF-MS/MS) combined with chemometrics showed the different impacts of the drying methods on the phytochemical composition of the alcoholic leaf extracts. Unsupervised principal component analysis (PCA) and supervised partial least squares-discriminant analysis (PLS-DA) of the LC-QTOF-MS/MS data showed distinct distant clustering across the three drying techniques. Loading plots and VIP scores demonstrated that sinapic acid, isorhamnetin glycosides, and sinapoyl malate were key markers for LY samples. Meanwhile, oxygenated and polyunsaturated fatty acids were characteristic for SD samples and oxygenated polyunsaturated fatty acids and verbascoside were characteristic for VO samples. LY resulted in the highest total phenolics (TP) and total flavonoid (TF) contents followed by SD and VO. LY and SD samples had much higher antioxidant activity than VO measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC), and iron metal chelation assays. According to the anticancer activity, the drying methods were ranked in descending order as SD > LY ≫ VO when tested against colon, breast, liver, and lung cancer cell lines. Among the identified compounds, flavonoids and omega-3 fatty acids were key metabolites responsible for the anticancer activity as revealed by partial least squares (PLS) regression and correlation analyses. In conclusion, compared to LY, SD projected out as a cost-effective drying method without compromising the phytochemical and biological activities of Brassica greens. The current findings lay the foundation for further studies concerned with the valorization of Brassica greens.

The effect of sourdough, turnips, and butternut squash on the physicochemical and nutritional properties of Doowina functional food during fermentation

The dairy-cereal-based food, known as Doowina, is one of the traditional fermented foods in Iran. We aimed to improve the health-promoting properties of Doowina by using turnips, butternut squash, and sourdough as a new functional food with high nutritional value and antioxidant activity. Therefore, the physicochemical, microbial, and sensory properties of samples with nutritional supplements (8% turnip and 8% butternut squash) and different concentrations of sourdough (0, 0.5, and 1%) were studied during 0, 3, 6, and 9 days of fermentation time. The results showed that there was no significant difference (p < .05) in the moisture and ash content between the different formulations of Doowina. There was also no significant difference (p < .05) in the phenolic compound content and antioxidant activity of the Doowina samples during the fermentation period. However, the number of lactic acid bacteria (LAB) increased significantly (p < .05) until the 6th day of fermentation, and the protein content decreased significantly (p < .05) in all samples during the fermentation period. According to the results, the samples with butternut squash and sourdough had the highest total phenolic content, the highest antioxidant activity, the highest linoleic acid content, and the highest sensory rating of all samples.

Inter-Varietal Variation in Phenolic Profile, Antioxidant, Anti-Inflammatory and Analgesic Activities of Two Brassica rapa Varieties: Influence on Pro-Inflammatory Mediators

The present research study aims to appraise the potential of polyphenol-rich extracts from two Brassica rapa varieties on antioxidant, anti-inflammatory and analgesic activities using carrageenan-induced paw edema model in rats. Methanol extracts of peels and pulps of Brassica rapa yellow root (BRYR) and Brassica rapa white root (BRWR) were prepared using the soxhlet extraction technique. All four extracts were analyzed by reversed-phase high-pressure liquid chromatography (RP-HPLC) for the polyphenols, and results showed that 10 phenolic acids and 4 flavonoids were detected. Gallic acid was the major phenolic acid (174.6-642.3 mg/100 g of dry plant material) while catechin was the major (34.45-358.5 mg/100 g of dry plant material) flavonoid detected in the extracts. The total phenolic contents (TPC) of BRYR peel, BRWR peel, BRYR pulp and BRWR pulp extracts were in the range of 1.21-5.01 mg/g of dry plant material, measured as GAE, whereas the total flavonoid contents (TFC) were found in the range of 0.90-3.95 mg/g of dry plant material, measured as QE. BRYR peel extract exhibited the best DPPH radical scavenging activity (IC50, 3.85 µg/mL) and reducing potential as compared with other extracts. The in vivo anti-inflammatory potential was assessed by carrageenan-induced rat paw edema, and the analgesic potential was investigated by a hot plate test. Suppression of biochemical inflammatory biomarkers including C-reactive protein (CRP), rheumatoid factor (RF) and tumor necrosis factor (TNF-α), and interleukin-6 (IL-6) concentration were also determined. Results showed that BRYR peel extracts reduced paw edema and suppressed the production of TNF-α, IL-6, CRP and RF most significantly, followed by BRWR peel, BRYR pulp and BRWR pulp extracts. In addition, histopathology observation also supports the anti-inflammatory effect of peel extracts as being greater than that of root pulp extracts. Moreover, it was observed that the analgesic effect of the root-peel extracts was also more pronounced as compared with root-pulp extracts. It can be concluded that BRYR peel extract has higher phenolic contents and showed higher suppression of TNF-α, IL-6, CRP and RF, with strong antioxidant, anti-inflammatory and analgesic effects.

The preventive effects of broccoli bioactives against cancer: Evidence from a validated rat glioma model

The aggressive and incurable diffuse gliomas constitute 80% of malignant brain tumors, and patients succumb to recurrent surgeries and drug resistance. Epidemiological research indicates that substantial consumption of fruits and vegetables diminishes the risk of developing this tumor type. Broccoli consumption has shown beneficial effects in both cancer and neurodegenerative diseases. These effects are partially attributed to the isothiocyanate sulforaphane (SFN), which can regulate the Keap1/Nrf2/ARE signaling pathway, stimulate detoxifying enzymes, and activate cellular antioxidant defense processes. This study employs a C6 rat glioma model to assess the chemoprotective potential of aqueous extracts from broccoli seeds, sprouts, and inflorescences, all rich in SFN, and pure SFN as positive control. The findings reveal that administering a dose of 100 mg/kg of broccoli sprout aqueous extract and 0.1 mg/kg of SFN to animals for 30 days before introducing 1 × 104 cells effectively halts tumor growth and progression. This study underscores the significance of exploring foods abundant in bioactive compounds, such as derivatives of broccoli, for potential preventive integration into daily diets. Using broccoli sprouts as a natural defense against cancer development might seem idealistic, yet this investigation establishes that administering this extract proves to be a valuable approach in designing strategies for glioma prevention. Although the findings stem from a rat glioma model, they offer promising insights for subsequent preclinical and clinical research endeavors.

The growth-immunity tradeoff in Brassica oleracea-Xanthomonas campestris pv. campestris pathosystem

Plant responses against pathogens are influenced by growth immunity tradeoff, which ensure the best use of limited resources. We study how the immobilization of carbon resources and the induction of defensive responses (glucosinolates, phenolic compounds, stomatal closure) can influence the biomass of two Brassica oleracea lines, differing in their resistance, after infection with Xanthomonas campestris pv. campestris. Potentially, the growth immunity tradeoff can be influenced by the activation of all these processes. However, on the contrary of which is normally stated, our results suggest that the loss of biomass caused by pathogen infection is mainly due to the differential accumulation of starch and the immobilization of sugars rather than the reallocation of resources to synthesize secondary metabolites. Moreover, resistance may be related to the effectiveness of the tradeoff, since the resistant line immobilizes resources more efficiently than the susceptible one. Both inbred lines show a different phytohormones profile, which support the hypothesis that they are employing different strategies to defend themselves against the pathogen. This study emphasizes the key role of the primary metabolism in the defence strategies of plants against pathogens.

Healthy regulation of Tibetan Brassica rapa L. polysaccharides on alleviating hyperlipidemia: A rodent study

Hyperlipidemia is a common metabolic disorder, which can lead to obesity, hypertension, diabetes, atherosclerosis and other diseases. Studies have shown that polysaccharides absorbed by the intestinal tract can regulate blood lipids and facilitate the growth of intestinal flora. This article aims to investigate whether Tibetan turnip polysaccharide (TTP) plays a protective role in blood lipid and intestinal health via hepatic and intestinal axes. Here we show that TTP helps to reduce the size of adipocytes and the accumulation of liver fat, playing a dose-dependent effect on ADPN levels, suggesting an effect on lipid metabolism regulation. Meantime, TTP intervention results in the downregulation of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and serum inflammatory factors (interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α)), implying that TTP suppresses the progression of inflammation in the body. The expression of key enzymes associated with cholesterol and triglyceride synthesis, such as 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), cholesterol 7α-hydroxylase (CYP7A1), peroxisome proliferator-activated receptors γ (PPARγ), acetyl-CoA carboxylase (ACC), fatty acid synthetase (FAS) and sterol-regulatory element binding proteins-1c (SREBP-1c), can be modulated by TTP. Furthermore, TTP also alleviates the damage to intestinal tissues caused by high-fat diet, restores the integrity of the intestinal barrier, improves the composition and abundance of the intestinal flora and increases the levels of SCFAs. This study provides a theoretical basis for the regulation of body rhythm by functional foods and potential intervention in patients with hyperlipidemia.

Effect of Sprouting on the Phenolic Compounds, Glucosinolates, and Antioxidant Activity of Five Camelina sativa (L.) Crantz Cultivars

Sprouts are increasingly present in the human diet, being tasty and healthy foods high in antioxidant compounds. Although there is a body of literature on the sprouting of many plant species, Camelina sativa (L.) Crantz has not yet been studied for this purpose. This study aimed to characterize the main bioactive compounds and antioxidant potential of seeds and sprouts of five different Camelina cultivars (ALBA, CO46, CCE43, JOELLE, and VERA). In particular, the contents of phenolic compounds (PCs), phenolic acids (PAs), and glucosinolates (GLSs) were investigated. PCs, PAs, GLSs, and the antioxidant activity of seeds differed among cultivars and were greatly increased by sprouting. A PCA analysis underlined both the effect of the cultivar (PC2) and the germination (PC1) on the nutritional properties of Camelina. The best nutritional properties of seeds were observed for ALBA and CCE43, while the best nutritional properties of sprouts were recorded for CCE43 and JOELLE, since the latter cultivar showed a greater enhancement in phytochemical content and antioxidant activity with sprouting. Finally, a UHPLC-UV procedure for the analysis of GLSs in Camelina was developed and validated. The performance criteria of the proposed method demonstrated that it is useful for the analysis of GLSs in Camelina.

New vegetable varieties of Brassica rapa and Brassica napus with modified glucosinolate content obtained by mass selection approach

Background

Glucosinolates (GSLs) constitute a characteristic group of secondary metabolites present in the Brassica genus. These compounds confer resistance to pests and diseases. Moreover, they show allelopathic and anticarcinogenic effects. All those effects are dependent on the chemical structure of the GSL. The modification of the content of specific GSLs would allow obtaining varieties with enhanced resistance and/or improved health benefits. Moreover, the attainment of varieties with the same genetic background but with divergent GSLs concentration will prompt the undertaking of studies on their biological effects.

Objective and Methods

The objective of this study was to evaluate the efficacy of two divergent mass selection programs to modify GSL content in the leaves of two Brassica species: nabicol (Brassica napus L.), selected by glucobrassicanapin (GBN), and nabiza (Brassica rapa L.), selected by gluconapin (GNA) through several selection cycles using cromatographic analysis.

Results

The response to selection fitted a linear regression model with no signs of variability depletion for GSL modification in either direction, but with higher efficiency in reducing the selected GSL than in the increasing. The selection was also effective in other parts of the plant, suggesting that there is a GSL translocation in the plant or a modification in their synthesis pathway that is not-organ specific. There was an indirect response of selection in other GSL; thus this information should be considered when designing breeding programs. Finally, populations obtained by selection have the same agronomic performance or even better than the original population.

Conclusion

Therefore, mass selection seems to be a good method to modify the content of specific GSL in Brassica crops.

Dynamic profiling of intact glucosinolates in radish by combining UHPLC-HRMS/MS and UHPLC-QqQ-MS/MS

Glucosinolates (GSLs) and their degradation products in radish confer plant defense, promote human health, and generate pungent flavor. However, the intact GSLs in radish have not been investigated comprehensively yet. Here, an accurate qualitative and quantitative analyses of 15 intact GSLs from radish, including four major GSLs of glucoraphasatin (GRH), glucoerucin (GER), glucoraphenin (GRE), and 4-methoxyglucobrassicin (4MGBS), were conducted using UHPLC-HRMS/MS in combination with UHPLC-QqQ-MS/MS. Simultaneously, three isomers of hexyl GSL, 3-methylpentyl GSL, and 4-methylpentyl GSL were identified in radish. The highest content of GSLs was up to 232.46 μmol/g DW at the 42 DAG stage in the 'SQY' taproot, with an approximately 184.49-fold increase compared to the lowest content in another sample. That the GSLs content in the taproots of two radishes fluctuated in a similar pattern throughout the five vegetative growth stages according to the metabolic profiling, whereas the GSLs content in the '55' leaf steadily decreased over the same period. Additionally, the proposed biosynthetic pathways of radish-specific GSLs were elucidated in this study. Our findings will provide an abundance of qualitative and quantitative data on intact GSLs, as well as a method for detecting GSLs, thus providing direction for the scientific progress and practical utilization of GSLs in radish.

Systematic Review on the Metabolic Interest of Glucosinolates and Their Bioactive Derivatives for Human Health

In the last decade, most of the evidence on the clinical benefits of including cruciferous foods in the diet has been focused on the content of glucosinolates (GSL) and their corresponding isothiocyanates (ITC), and mercapturic acid pathway metabolites, based on their capacity to modulate clinical, biochemical, and molecular parameters. The present systematic review summarizes findings of human studies regarding the metabolism and bioavailability of GSL and ITC, providing a comprehensive analysis that will help guide future research studies and facilitate the consultation of the latest advances in this booming and less profusely researched area of GSL for food and health. The literature search was carried out in Scopus, PubMed and the Web of Science, under the criteria of including publications centered on human subjects and the use of Brassicaceae foods in different formulations (including extracts, beverages, and tablets), as significant sources of bioactive compounds, in different types of subjects, and against certain diseases. Twenty-eight human intervention studies met inclusion criteria, which were classified into three groups depending on the dietary source. This review summarizes recent studies that provided interesting contributions, but also uncovered the many potential venues for future research on the benefits of consuming cruciferous foods in our health and well-being. The research will continue to support the inclusion of GSL-rich foods and products for multiple preventive and active programs in nutrition and well-being.

Metabolic diversity in a collection of wild and cultivated Brassica rapa subspecies

Brassica rapa (B. rapa) and its subspecies contain many bioactive metabolites that are important for plant defense and human health. This study aimed at investigating the metabolite composition and variation among a large collection of B. rapa genotypes, including subspecies and their accessions. Metabolite profiling of leaves of 102 B. rapa genotypes was performed using ultra-performance liquid chromatography coupled with a photodiode array detector and quadrupole time-of-flight mass spectrometry (UPLC-PDA-QTOF-MS/MS). In total, 346 metabolites belonging to different chemical classes were tentatively identified; 36 out of them were assigned with high confidence using authentic standards and 184 were those reported in B. rapa leaves for the first time. The accumulation and variation of metabolites among genotypes were characterized and compared to their phylogenetic distance. We found 47 metabolites, mostly representing anthocyanins, flavonols, and hydroxycinnamic acid derivatives that displayed a significant correlation to the phylogenetic relatedness and determined four major phylometabolic branches; 1) Chinese cabbage, 2) yellow sarson and rapid cycling, 3) the mizuna-komatsuna-turnip-caitai; and 4) a mixed cluster. These metabolites denote the selective pressure on the metabolic network during B. rapa breeding. We present a unique study that combines metabolite profiling data with phylogenetic analysis in a large collection of B. rapa subspecies. We showed how selective breeding utilizes the biochemical potential of wild B. rapa leading to highly diverse metabolic phenotypes. Our work provides the basis for further studies on B. rapa metabolism and nutritional traits improvement.

Dietary-Fibre-Rich Fractions Isolated from Broccoli Stalks as a Potential Functional Ingredient with Phenolic Compounds and Glucosinolates

The Brassica oleracea industry generates large amounts of by-products to which value could be added because of the characteristics of their composition. The aim was to extract different fibre fractions from broccoli stalks to obtain potential new added-value ingredients. Using an ethanol and water extraction procedure, two fibre-rich fractions (total fibre fraction, TF_B, and insoluble fibre fraction, IF_B) were obtained. These fractions were analysed to determine the nutritional, (poly)phenols and glucosinolates composition and physicochemical properties, comparing the results with those of freeze-dried broccoli stalks (DBS). Although TF_B showed a higher content of total dietary fibre, IF_B had the same content of insoluble dietary fibre as TF_B (54%), better hydration properties, higher content of glucosinolates (100 mg/100 g d.w.) and (poly)phenols (74.7 mg/100 g d.w.). The prebiotic effect was evaluated in IF_B and compared with DBS by in vitro fermentation with human faecal slurries. After 48 h, the short-chain fatty acid (SCFA) production was higher with IF_B than with DBS because of the greater presence of both uronic acids, the main component of pectin, and (poly)phenols. These results reveal that novel fibre-rich ingredients—with antioxidant, technological and physiological effects—could be obtained from broccoli stalks by using green extraction methods.

Identification and quantification of intact glucosinolates at different vegetative growth periods in Chinese cabbage cultivars by UHPLC-Q-TOF-MS

The aims of this study were to investigate glucosinolate variations in Chinese cabbage cultivars at different growth periods. Glucosinolates in two types of Chinese cabbage (Xiayangbai and Zaoshu-5) at different growth periods (seeds, germination, seedling, and rosette period) were investigated. Thirteen glucosinolates were identified and quantified using UHPLC-Q-TOF-MS. Concentrations of the glucosinolates were significantly different between Xiayangbai and Zaoshu-5. The seed period generated the highest concentration of glucosinolates, and aliphatic glucosinolate predominated in seeds, seedling, and leaves of the rosette as well as during germination. However, the dominant glucosinolate in the roots was an aromatic glucosinolate (gluconasturtiin). In addition, glucoerucin was only found in the roots of rosettes. There were positive significant correlations with each other among gluconapin, glucobrassicanapin, glucoraphanin, glucoalyssin, and 4-hydroxyglucobrassicin. Our results released the metabolism pathways of glucosinolates in Chinese cabbage, which provided scientific evidence to develop functional foods with higher glucosinolate.

Variation of Nutritional Quality Depending on Harvested Plant Portion of Broccoli and Black Cabbage

Brassicaceae plants are rich with antioxidant compounds that play a key role for human health. This study wants to characterize two Italian broccoli cultivars (Roya and Santee) and black cabbage, evaluating the variation of antioxidants in different portion and at different developmental stage of the plants: for broccoli, heads and stems were sampled, while for black cabbage, leaves and seeds were analyzed. Roja cultivar was also analyzed at the first and second harvest to evaluate the variation of phytochemical compounds over time. Nutritional and sensorial qualities were investigated. Black cabbage seeds showed higher value of total antioxidants, total phenols, and total anthocyanins than leaves. Similarly, phenolics and anthocyanins content in head was higher than in stem in broccoli. In Roja cultivar, the harvest date seemed to influence the antioxidant capacity and the phytochemical compounds content, with broccoli sampled in the second harvest showing better results for all the nutritional parameters. These local vegetables represent a significant source of antioxidants and may contribute to health benefits of the consumers.

Maximization of Sulforaphane Content in Broccoli Sprouts by Blanching

Broccoli sprouts are a recognized source of health-promoting compounds, such as glucosinolates, glucoraphanin, and sulforaphane (SFN). Maximization of SFN content can be achieved by technological processing. We investigated the effect of blanching conditions to determine the optimal treatment that maximizes sulforaphane content in broccoli sprouts. Broccoli seeds (cv. Traditional) grown under controlled conditions were harvested after 11 days from germination and subjected to different blanching conditions based on a central composite design with temperature and time as experimental factors. Results were analyzed by ANOVA followed by a Tukey test. The optimum conditions were identified through response surface methodology. Blanching increased sulforaphane content compared with untreated sprouts, agreeing with a decrease in total glucosinolates and glucoraphanin content. Temperature significantly affected SFN content. Higher temperatures and shorter immersion times favor glucoraphanin hydrolysis, thus increasing SFN content. The optimum conditions were blanching at 61 °C for 4.8 min, resulting in 54.3 ± 0.20 µmol SFN/g dry weight, representing a 3.3-fold increase with respect to untreated sprouts. This is the highest SFN content reported for sprouts subjected to any treatment so far. The process described in this work may contribute to developing functional foods and nutraceuticals that provide sulforaphane as an active principle.

Development of a quantification method for routine analysis of glucosinolates and camalexin in brassicaceous small-sized samples by simultaneous extraction prior to liquid chromatography determination

Glucosinolates and camalexin are secondary metabolites that, as phytoanticipins and phytoalexins, play a crucial role in plant defence. The present work proposes an improved analytical method for routine analysis and quantification of glucosinolates and camalexin in brassicaceous small-sized samples by using the very specific desulfation process of glucosinolates analysis and the specificity of fluorescence detection for camalexin analysis. The approach is based on a simultaneous ultrasound-assisted extraction followed by a purification on an anion-exchange column. Final analyses are conducted by HPLC-UV-MS for desulfo-glucosinolates and HPLC coupled to a fluorescence detector (HPLC-FLD) for camalexin. The method is linear for glucosinolates (50-3500 µM) and camalexin (0.025-5 µg.mL^-1) with an LOD/LOQ of 3.8/12.6 µM and 0.014/0.046 µg.mL^-1 respectively. The method demonstrated adequate precision, accuracy and trueness on certified reference rapeseed. A practical application of our approach was conducted on different Brassicaceae genera (Barbarea vulgaris, Brassica nigra, Capsella bursa-pastoris, Cardamine hirsuta, Coincya monensis, Sinapis arvensis, and Sisymbrium officinale) and Arabidopsis thaliana genotypes (Columbia and Wassilewskija). Futhermore, different plant organs (seeds and leaves) were analysed, previously inoculated or not with the pathogenic fungus Alternaria brassicicola.

Identification and Quantification of Glucosinolates and Phenolics in a Large Panel of Brassica napus Highlight Valuable Genetic Resources for Chemical Ecology and Breeding

Glucosinolate (GLS) and phenolic contents in Brassicaceae contribute to biotic and abiotic stress responses. Breeding crop accessions harboring agroecologically relevant metabolic profiles require a characterization of the chemical diversity in Brassica germplasm. This work investigates the diversity of specialized metabolites in 281 accessions of B. napus. First, an LC-HRMS2-based approach allowed the annotation of 32 phenolics and 36 GLSs, revealing 13 branched and linear alkyl-GLSs and 4 isomers of hydroxyphenylalkyl-GLSs, many of which have been rarely reported in Brassica. Then, quantitative UPLC-UV-MS-based profiling was performed in leaves and roots for the whole panel. This revealed striking variations in the content of 1-methylpropyl-GLS (glucocochlearin) and a large variation of tetra- and penta-glucosyl kaempferol derivatives among accessions. It also highlighted two main chemotypes related to sinapoyl-O-hexoside and kaempferol-O-trihexoside contents. By offering an unprecedented overview of the phytochemical diversity in B. napus, this work provides a useful resource for chemical ecology and breeding.

Effect of a Sub-Chronic Oral Exposure of Broccoli (Brassica oleracea L. Var. Italica) By-Products Flour on the Physiological Parameters of FVB/N Mice: A Pilot Study

Brassica by-products are a source of natural bioactive molecules such as glucosinolates and isothiocyanates, with potential applications in the nutraceutical and functional food industries. However, the effects of oral sub-chronic exposure to broccoli by-product flour (BF) have not yet been evaluated. The objective of this pilot study was to analyse the effects of BF intake in the physiological parameters of FVB/N mice fed a 6.7% BF-supplemented diet for 21 days. Glucosinolates and their derivatives were also quantified in plasma and urine. BF supplementation significantly decreased (p < 0.05) the accumulation of perirenal adipose tissue. Furthermore, mice supplemented with BF showed significantly lower (p < 0.01) microhematocrit values than control animals, but no impact on the general genotoxicological status nor relevant toxic effects on the liver and kidney were observed. Concerning hepatic and renal antioxidant response, BF supplementation induced a significant increase (p < 0.05) in the liver glutathione S-transferase (GST) levels. In BF-supplemented mice, plasma analysis revealed the presence of the glucosinolates glucobrassicin and glucoerucin, and the isothiocyanates sulforaphane and indole-3-carbinol. Overall, these results show that daily intake of a high dose of BF during three weeks is safe, and enables the bioavailability of beneficial glucosinolates and isothiocyanates. These results allow further testing of the benefits of this BF in animal models of disease, knowing that exposure of up to 6.7% BF does not present relevant toxicity.

Determination of 18 Intact Glucosinolates in Brassicaceae Vegetables by UHPLC-MS/MS: Comparing Tissue Disruption Methods for Sample Preparation

Glucosinolates (GSLs) are important precursor compounds with anticancer activities in Brassicaceae vegetables and are readily hydrolyzed by myrosinase. Given the diversity of these species, establishing an accurate and universal method to quantify intact GSLs in different plant tissues is necessary. Here, we compared and optimized three tissue disruption methods for sample preparation. After microwave treatment for 90 s, 13 GSLs in homogenized Chinese cabbage samples were recovered at 73–124%. However, a limitation of this method was that different tissues could not be processed under the same microwave conditions. Regarding universality, GSLs in Brassicaceae vegetables could be extracted from freeze-dried sample powder with 70% methanol (v/v) or frozen-fresh sample powder with 80% methanol (v/v). Moreover, heating extraction is necessary for GSLs extracted from frozen-fresh sample powder. Average recoveries of the two optimized methods were 74–119% with relative standard deviations ≤ 15%, with the limits of quantification 5.72–17.40 nmol/g dry weight and 0.80–1.43 nmol/g fresh weight, respectively. Notably, the method for analyzing intact GSLs was more efficient than that for desulfo-GSLs regarding operational complexity, detection speed and quantification accuracy. The developed method was applied to identify the characteristic GSLs in 15 Brassicaceae vegetables, providing a foundation for further research on GSLs.

Antimicrobial Activity of Brassica rapa L. Flowers Extract on Gastrointestinal Tract Infections and Antiulcer Potential Against Indomethacin-Induced Gastric Ulcer in Rats Supported by Metabolomics Profiling

INTRODUCTION

The gastrointestinal tract (GIT) is vulnerable to various diseases. In this study, we explored the therapeutic effects of Brassica rapa flower extract (BRFE) on GIT diseases.

METHODS

Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used for phytochemical identification of the compounds in BRFE. The antibacterial activity of BRFE was investigated, and its impact on the bacterial outer and inner membrane permeability and membrane depolarization (using flow cytometry) was studied. In addition, the immunomodulatory activity of BRFE was investigated in vitro on lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMCs) using quantitative reverse transcription polymerase chain reaction (qRT-PCR). Furthermore, the anti-inflammatory activity of BRFE was investigated by histopathological examination and qRT-PCR on indomethacin-induced gastric ulcers in rats.

RESULTS AND DISCUSSION

LC-ESI-MS/MS phytochemically identified 57 compounds in BRFE for the first time. BRFE displayed antibacterial activity against bacteria that cause GIT infections, with increasing outer and inner membrane permeability. However, membrane depolarization was unaffected. BRFE also exhibited immunomodulatory activity in LPS-stimulated PBMCs by attenuating the upregulation of cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin (IL)-6, tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa B (NF-κB) gene expression compared with untreated LPS-stimulated PBMCs. In addition, BRFE exhibited anti-inflammatory activity required for maintaining gastric mucosa homeostasis by decreasing neutrophil infiltration with subsequent myeloperoxidase production, in addition to an increase in glutathione peroxidase (GPx) activity. Histopathological findings presented the gastroprotective effects of BRFE, as a relatively normal stomach mucosa was found in treated rats. In addition, BRFE modulated the expression of genes encoding IL-10, NF-κB, GPx, and myeloperoxidase (MPO).

CONCLUSION

BRFE can be a promising source of therapeutic agents for treatment of GIT diseases.

Role of Glucosinolates in the Nutraceutical Potential of Selected Cultivars of Brassica rapa

Brassica rapa L. subsp. rapa (turnip greens), a traditionally consumed vegetable, is well-known due to its high content of glucosinolates, which are secondary metabolites with a positive biological activity for human health. Our hypothesis has been based on the relation between B. rapa glucosinolate content and its healthy properties, and our aim is to establish guidelines for safe B. rapa vegetable consumption. Three B. rapa cultivars (143N5, 143N7 and 163N7) have been characterized by HPLC analysis of purified extracts from leaf samples in order to determine their glucosinolate content and to relate this content to beneficial effects on DNA protection, lifespan extension and chemoprevention. In order to ascertain the heath properties in vitro and in vivo, toxicity activities were assayed in the Drosophila melanogaster and leukaemia cell models; genomic safety was also assessed in both models using genotoxicity, fragmentation and comet assay. The Drosophila model has also been used to study the antioxidative activity and the longevity induction. Our results showed a relationship between B. rapa glucosinolate content and its safety and benefices in its consumption. Gluconapin, the main B. rapa glucosinolate, was directly related with these wholesome effects. The relevant conclusion in the present research is focused on B. rapa cultivar 163N7 due to its high gluconapin content and low progoitrin content, which exert anti-cancer and DNA protection properties and could be recommended as being safe and healthy for human consumption.

The petroleum ether extract of Brassica rapa L. induces apoptosis of lung adenocarcinoma cells via the mitochondria-dependent pathway

Brassica rapa L. is one of the most popular traditional foods with a variety of biological activities. In this study, the petroleum ether extract of B. rapa was separated by silica gel column chromatography, and named BRPS, which was identified by LC-MS. The effects and pharmacological mechanisms of BRPS on the treatment of lung cancer were investigated both in vitro and in vivo. The results showed that BRPS significantly inhibited the proliferation of both human lung cancer A549 and mouse lung cancer LLC cells, while its toxicity to normal cells was lower than that of cancer cells. BRPS induced cell cycle arrest at the G2/M phase and significantly reduced the levels of CDK1 and CyclinB1 in A549 cells. Moreover, BRPS induced apoptosis in a dose-dependent manner, and increased the Bax/Bcl-2 ratio, while it decreased mitochondrial membrane potential, promoted the release of cytochrome c, activated caspase 9 and 3, and enhanced the degradation of PARP in A549 cells. Furthermore, the levels of reactive oxygen species (ROS) were also upregulated by BRPS and ROS inhibitor reversed BRPS-induced apoptosis. Importantly, BRPS significantly suppressed the growth of LLC cells in vivo without any obvious side effect on body weight and organs of mice, and increased the proportion of B cells, CD4⁺ T cells, CD8⁺ T cells and CD44⁺CD8⁺ T cells in the spleen. These results revealed that BRPS inhibited the growth of lung cancer cells through inducing cell cycle arrest, mitochondria-dependent apoptosis, and activating immunity of mice, and BRPS might be a potential anti-tumor functional food and promising agent for the treatment of lung cancer.

Optimization of an Extraction Process to Obtain a Food-Grade Sulforaphane-Rich Extract from Broccoli (Brassica oleracea var. italica)

Sulforaphane (SFN) is a powerful health-promoting compound found in broccoli in the form of its inactive precursor, glucoraphanin (GFN). SFN formation occurs through the enzymatic hydrolysis of glucoraphanin by myrosinase under specific chemical conditions. Its incorporation in food formulations has been hindered by the thermal instability of SFN and low concentration in Brassicaceae. Then, extracting SFN from broccoli at a temperature below 40 °C appears as an option to recover and stabilize SFN, aiming at delivering it as a nutraceutical. We studied an eco-friendly extraction process to obtain an SFN-rich extract from broccoli. The effect of the broccoli mass/solvent ratio, ethanol concentration in the extractant solution, and extraction time on the recovery of SFN, GFN, phenolic compounds, and antioxidant activity were studied through a Box–Behnken design. The regression models explained more than 70% of the variability in the responses, adequately representing the system. The experimental factors differently affected the bioactive compound recovery and antioxidant activity of the extracts. The extraction conditions that allowed the highest recovery of bioactive compounds and antioxidant activity were identified and experimentally validated. The results may provide the basis for the design of a process to produce a sulforaphane-rich food supplement or nutraceutical by using a GRAS extractant.

Effect of Laser Light on Growth, Physiology, Accumulation of Phytochemicals, and Biological Activities of Sprouts of Three Brassica Cultivars

Brassica sprouts are known as a good source of antimicrobial bioactive compounds such as phenolics and glucosinolates (GLs). We aim at understanding how He-Ne laser light treatment (632 nm, 5 mW) improves sprout growth and physiology and stimulates the accumulation of bioactive metabolites in three Brassica spp., i.e., mustard, cauliflower, and turnip. Moreover, how these changes consequently promote their biological activities. Laser light improved growth, photosynthesis, and respiration, which induced the accumulation of primary and secondary metabolites. Laser light boosted the levels of pigments, phenolics, and indole and aromatic precursors of GLs, which resulted in increased total GLs and glucoraphanin contents. Moreover, laser light induced the myrosinase activity to provoke GLs hydrolysis to bioactive sulforaphane. Interestingly, laser light also reduced the anti-nutrient content and enhanced the overall biological activities of treated sprouts including antioxidant, antibacterial, anti-inflammatory, and anticancer activities. Accordingly, laser light is a promising approach for boosting the accumulation of beneficial metabolites in Brassica sprouts and, subsequently, their biological activities.

Current analytical methods for determination of glucosinolates in vegetables and human tissues

Numerous epidemiological studies have indicated the potential effects of glucosinolates and their metabolites against cancer as well as other non-communicable diseases, such as cardiovascular disease and neurodegenerative disorders. However, information on the presence and quantity of glucosinolates in commonly consumed vegetables and in human fluids is sparse, largely because well-standardised methods for glucosinolate determination are not available, resulting in published data being inconsistent and conflicting. Thus, studies published since 2002 on the most recent developments of glucosinolate extraction and identification have been collected and reviewed with emphasis on determination of the intact glucosinolates by LC-MS and LC-MS/MS. This overview highlights the glucosinolate extraction methods used, the stability of glucosinolates during extraction, the availability of stable isotope labelled internal standards and the use of NMR for purity analysis, as well as the current analytical techniques that have been applied for glucosinolate analysis, e.g. liquid chromatography with mass spectrometric detection (LC-MS). It aims to interpret the findings with a focus on the development of a validated method, which will help to determine the glucosinolate content of vegetative plants and human tissues, and the identification and determination of selected glucosinolate metabolites.

Environmental Conditions and Agronomical Factors Influencing the Levels of Phytochemicals in Brassica Vegetables Responsible for Nutritional and Sensorial Properties

Recently, the consumption of healthy foods has been related to the prevention of cardiovascular, degenerative diseases and different forms of cancers, underlying the importance of the diet for the consumer’s health. Fruits and vegetables contain phytochemicals that act as protective factors for the human body, through different mechanisms of action. Among vegetables, Brassica received a lot of attention in the last years for the phytochemical compounds content and antioxidant capacity that confer nutraceutical value to the product. The amount of healthy bioactive compounds present in the Brassica defines the nutritional quality. These molecules could belong to the class of antioxidant compounds (e.g., phenols, vitamin C, etc.), or to non-antioxidant compounds (e.g., minerals, glucosinolates, etc.). The amount of these compounds in Brassica vegetables could be influenced by several factors, depending on the genotypes, the environmental conditions and the cultivation techniques adopted. The aim of this study is to highlight the main phytochemical compounds present in brassicas used as a food vegetable that confer nutritional and sensorial quality to the final product, and to investigate the main factors that affect the phytochemical concentration and the overall quality of Brassica vegetables.

Phytochemical characterization of turnip greens (Brassica rapa ssp. rapa): A systematic review

Objective

The Turnip (Brassica rapa L. ssp. rapa) is a leaf and root vegetable grown and consumed worldwide. The consumption of Turnip has been associated with beneficial effects on human health due to their phytochemicals that may control a variety of physiological functions, including antioxidant activity, enzyme regulation, and apoptotic control and the cell cycle. The current systematic review of the literature aims to evaluate both the profile and quantity of phytochemicals commonly found in Turnip greens and to provide perspectives for further investigation.

Methods

This review was conducted following the PRISMA guidelines. Four bibliographic databases (PubMed, Embase, Web-of-Science and Cochrane Central Register of Controlled Trials) were searched to identify published studies until April 8th, 2020 (date last searched) without data and language restriction. Studies were included if they used samples of Turnip greens (the leaves), and evaluated its phytochemical content. Two reviewers independently evaluated the titles and abstracts according to the selection criteria. For each potentially eligible study, two reviewers assessed the full-texts and independently extracted the data using a predesigned data extraction form.

Results

Based on the search strategy 5,077 potentially relevant citations were identified and full texts of 37 studies were evaluated, among which 18 studies were eligible to be included in the current review. The majority of included studies were focused on identification of glucosinolates and isothiocyanates (n = 14, 82%), four studies focused on organic acids, and five studies reported phenolic component profile in Turnip greens. Among included studies nine studies (50%) provided information on phytochemical’s content. We found 129 phytochemicals (19 glucosinolates, 33 glucosinolate-breakdown products, 10 organic acids and 59 polyphenolic compounds) reported in Turnip greens. Flavonoids were mainly present as quercetin, kaempferol and isorhamnetin derivatives; while aliphatic forms were the predominant glucosinolate (gluconapin was the most common across five studies, followed by glucobrassicanapin). In general, the phytochemical content varied among the leaves, tops and Turnip roots.

Conclusions

Emerging evidence suggests the Turnip as a substantial source of diverse bioactive compounds. However, detailed investigation on the pure compounds derived from Turnip green, their bioavailability, transport and metabolism after consumption is further needed. Additional studies on their biological activity are crucial to develop dietary recommendations on the effective dosage and dietary recommendation of Turnip greens for nutrition and health.

Comparative study of young shoots and the mature red headed cabbage as antioxidant food resources with antiproliferative effect on prostate cancer cells

The increasing knowledge on health benefit properties of plant origin food ingredients supports recommendations for the use of edible plants in the prevention of diet related diseases, including cancer. The beneficial effects of young shoots of red cabbage can be attributed to their mixture of phytochemicals possessing antioxidant and potential anticancer activity. The objective of this study was to compare the content of bioactive compounds, including HPLC analysis of polyphenols and antioxidant activity of young shoots of red cabbage and the vegetable at full maturity. The content of vitamin C and polyphenols in juices obtained from young shoots and the mature vegetable were also determined. The other aim of this study was to confirm the hypothesis that juice of young shoots more effectively, compared to juice of the mature vegetable, reduces the proliferation of prostate cancer cell lines DU145 and LNCaP in vitro. A significantly higher content of vitamin C and carotenoids, as well as a higher antioxidant activity were found in edible young shoots in comparison to the mature vegetable. In addition, studies have shown higher amount of vitamin C in the juice of young shoots than in the juice of the mature vegetable and similar content of polyphenolic compounds. The level of total polyphenol content in the studied plant samples did not differ significantly. Flavonoids were the main polyphenols in young shoots and juice obtained from them, while phenolic acids were dominant in the mature vegetable and in juice obtained from it. The juice of young shoots has shown stronger in vitro anti-proliferation effect against prostate cancer cells than juice of the mature vegetable.

Young shoots of red cabbage could be a good source of phytochemicals with potential anticancer activity.

Seasonal Variation of Health-Promoting Bioactives in Broccoli and Methyl-Jasmonate Pre-Harvest Treatments to Enhance Their Contents

Broccoli is a source of bioactive compounds that provide an important nutritional value. The content of these compounds can vary depending on agronomic and environmental conditions, as well as on elicitation. In this study, three crop trials were carried out to evaluate the effects of the cultivation season, the application of different dosages of methyl-jasmonate (MeJA) on the overall quality and on the total content of bioactive compounds of 'Parthenon' broccoli cultivated under the field conditions of southeastern Spain. Color parameters, chlorophyll content, total phenolic compounds, total flavonoids and antioxidant activity were measured to evaluate the overall quality. Moreover, individual carotenoids, phenolic compounds and glucosinolates were evaluated by high performance liquid chromatography with diode array detection (HPLC-DAD) and high performance liquid chromatography equipped with diode array detector coupled to mass spectrometer using electro spray ionization (HPLC-DAD-ESI/MSn). The content of total carotenoids, phenolic compounds and glucosinolates were higher in autumn compared with spring, showing increases of 2.8-fold, 2-fold and 1.2-fold, respectively. Moreover, a double application of MeJA increased the contents of total carotenoids, phenolic compounds and glucosinolates by 22%, 32% and 39%, respectively, relative to the untreated samples. Considering our results, the controlled and timely application of 250 µM MeJA to the aerial parts of the plants four days before harvest, on two consecutive days, seems to be a valid agronomic strategy to improve the health-promoting capacity of Parthenon broccoli, without compromising its overall quality.

Pre- and Post-harvest Factors Affecting Glucosinolate Content in Broccoli

Owing to several presumed health-promoting biological activities, increased attention is being given to natural plant chemicals, especially those frequently entering the human diet. Glucosinolates (GLs) are the main bioactive compounds found in broccoli (Brassica oleracea L. var. italica Plenck). Their regular dietary assumption has been correlated with reduced risk of various types of neoplasms (lung, colon, pancreatic, breast, bladder, and prostate cancers), some degenerative diseases, such as Alzheimer's, and decreased incidence of cardiovascular pathologies. GL's synthesis pathway and regulation mechanism have been elucidated mainly in Arabidopsis. However, nearly 56 putative genes have been identified as involved in the B. oleracea GL pathway. It is widely recognized that there are several pre-harvest (genotype, growing environment, cultural practices, ripening stage, etc.) and post-harvest (harvesting, post-harvest treatments, packaging, storage, etc.) factors that affect GL synthesis, profiles, and levels in broccoli. Understanding how these factors act and interact in driving GL accumulation in the edible parts is essential for developing new broccoli cultivars with improved health-promoting bioactivity. In this regard, any systematic and comprehensive review outlining the effects of pre- and post-harvest factors on the accumulation of GLs in broccoli is not yet available. Thus, the goal of this paper is to fill this gap by giving a synoptic overview of the most relevant and recent literature. The existence of substantial cultivar-to-cultivar variation in GL content in response to pre-harvest factors and post-harvest manipulations has been highlighted and discussed. The paper also stresses the need for adapting particular pre- and post-harvest procedures for each particular genotype in order to maintain nutritious, fresh-like quality throughout the broccoli value chain.

Effect of Drum-Drying Conditions on the Content of Bioactive Compounds of Broccoli Pulp

This work studied the effect of drum-rotation frequency, drum temperature, and water-to-pulp ratio in a double-drum drier on the content of sulforaphane, glucoraphanin, total phenolic compounds, ascorbic acid, and antioxidant activity of broccoli pulp through a multilevel factorial design with one replicate. Drum-drying conditions did not significantly affect sulforaphane content, unlike glucoraphanin, however the poor adherence of broccoli pulp resulted in a final product with undefined shape and heterogeneous color. On the other hand, antioxidant activity was unevenly affected by drying conditions; however, drum-rotation frequency affected it in the same way that phenolic compounds and ascorbic acid, showing a concordant behavior. The ascorbic acid content decreased significantly after drying, and it was highly dependent on the experimental factors, resulting in a regression model that explained 90% of its variability. Drum-rotation frequency of 5 Hz, drum temperature of 125 °C, and water-to-pulp ratio of 0.25 resulted in an apparent increase of sulforaphane and phenolic compounds content of 13.7% and 47.6%, respectively. Drum drying has great potential to fabricate dehydrated broccoli-based foods with functional properties. Besides, since drum drying has low investment and operation costs, it represents a very attractive option for the industrialization of broccoli derivatives.

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.

Composted Sewage Sludge Influences the Microbiome and Persistence of Human Pathogens in Soil

Composted sewage sludge (CSS) gained attention as a potential fertilizer in agriculture. Application of CSS increases soil microbial activity and microbial biomass, however, it can also lead to increased chemical and microbiological risks. In this study, we performed microcosm experiments to assess how CSS reshapes the microbial community of diluvial sand (DS) soil. Further, we assessed the potential of CSS to increase the persistence of human pathogens in DS soil and the colonization of Chinese cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt). The results revealed that CSS substantially altered the prokaryotic community composition. Moreover, addition of CSS increased the persistence of Salmonella enterica serovar Typhimurium strain 14028s and S.enterica serovar Senftenberg in DS soil. However, the enhanced persistence in soil had no impact on the colonization rate of B.rapa grown on soil inoculated with Salmonella. We detected Salmonella in leaves of 1.9% to 3.6% of plants. Addition of CSS had no impact on the plant colonization rate. The use of sewage sludge composts is an interesting option. However, safety measures should be applied in order to avoid contamination of crop plants by human pathogens.

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.

Comparative Metabolomics Revealed the Potential Antitumor Characteristics of Four Endophytic Fungi of Brassica rapa L

Endophytic fungi of medicinal plants have attracted wide attention due to their various active biochemical substances that are similar to those of the host plants and can be easily fermented and cultured. As a traditional medicine and food homologous plant in Xinjiang, Brassica rapa L. has a long history of applications. Recently, it has been shown that B. rapa L. has hypoglycemic, antimicrobial, immunomodulatory, and antioxidant properties. However, there are no studies on the function and diversity of enophytic fungi of B. rapa L. Four endophytic fungus (pr6, pr7, pr8, and pr10) strains were isolated from B. rapa L. in our laboratory. The metabolic extracts from pr10 have significant effects in terms of antitumor activity. In this study, in terms of types and contents, compared with those of the other three endophytic fungi, the dominant metabolites of pr10 were determined by comparative metabolomics analysis. The results of metabolomics analysis indicated that the metabolites of pr10 are rich in amino acids and sugar derivatives such as trehalose, whose ability to inhibit the A549 cell line has been proved. This study provides a theoretical basis for the development and utilization of B. rapa L. and its endophytic fungi to form antitumor agents.

Liquiritin elicitation can increase the content of medicinally important glucosinolates and phenolic compounds in Chinese kale plants

BACKGROUND

Brassica oleracea var. alboglabra (Chinese kale) is an important vegetable grown in southern China. This study was aimed at searching for environmentally friendly and affordable approaches to increase the production of medicinally relevant glucosinolates and phenolic compounds in Chinese kale plants. For this purpose, the foliar application of liquiritin at 0 (control), 250, 500 and 750 ppm was tested starting from the four-leaf stage and repeated every two weeks until plants were two months old.

RESULTS

Foliar application of liquiritin in Chinese kale plants significantly increased glucosinolates and total phenolic content, in a dose-dependent manner. Compared with control plants, 2.3- and 1.9-fold increases in yields of glucosinolates and total phenolic content, respectively, were corroborated in Chinese kale plants treated with 750 ppm of liquiritin. Along with rises in the content of eight different glucosinolates, liquiritin elicitation effectively increased the concentration of glycosilated and acylated flavonoids and hydroxycinnamic acids. The expression of genes involved in glucosinolate and phenolic biosynthesis was significantly higher in liquiritin-treated plants as compared to controls.

CONCLUSIONS

Liquiritin elicitation is a feasible and environmentally friendly practice for increasing the production of medicinally important glucosinolates and phenolic compounds in Chinese kale, which may improve this plant's value as a nutraceutical food. This study also contributes to understanding the molecular mechanisms underlying liquiritin elicitation. This is the first report documenting the use of liquiritin for an elicitation purpose in plants. © 2019 Society of Chemical Industry.

Molecular Modeling of Epithiospecifier and Nitrile-Specifier Proteins of Broccoli and Their Interaction with Aglycones

Glucosinolates are secondary plant metabolites of Brassicaceae. They exert their effect after enzymatic hydrolysis to yield aglycones, which become nitriles and epithionitriles through the action of epithiospecifier (ESP) and nitrile-specifier proteins (NSP). The mechanism of action of broccoli ESP and NSP is poorly understood mainly because ESP and NSP structures have not been completely characterized and because aglycones are unstable, thus hindering experimental measurements. The aim of this work was to investigate the interaction of broccoli ESP and NSP with the aglycones derived from broccoli glucosinolates using molecular simulations. The three-dimensional structure of broccoli ESP was built based on its amino-acid sequence, and the NSP structure was constructed based on a consensus amino-acid sequence. The models obtained using Iterative Threading ASSEmbly Refinement (I-TASSER) were refined with the OPLS-AA/L all atom force field of GROMACS 5.0.7 and were validated by Veryfy3D and ERRAT. The structures were selected based on molecular dynamics simulations. Interactions between the proteins and aglycones were simulated with Autodock Vina at different pH. It was concluded that pH determines the stability of the complexes and that the aglycone derived from glucoraphanin has the highest affinity to both ESP and NSP. This agrees with the fact that glucoraphanin is the most abundant glucosinolate in broccoli florets.

Developmentally-related changes in phenolic and L-ascorbic acid content and antioxidant capacity of Chinese cabbage sprouts

The phytochemical and antioxidant properties of mature (head stage) Chinese cabbage (Brassica rapa ssp. pekinensis) are known; however, data on the phenolic profile, vitamin C (L-ascorbic acid) content and antioxidant capacity of its fresh sprouts are lacking. Since the human consumption of fresh cruciferous sprouts has significantly increased in recent years, their nutritional characterization has become a somewhat urgent matter. Therefore, in this study the contents of total phenolics, flavonols and hydroxycinnamic acids were measured spectrophotometrically, whereas individual flavonoids, phenolic acids and vitamin C were identified and quantified using a newly-developed high performance liquid chromatography method. Also, the antioxidant capacity of five Chinese cabbage sprout growth stages was determined. These stages contained either cotyledons only (seedlings), cotyledons and two leaves, four leaves, six leaves, or ten leaves. Principal component analysis (PCA) and hierarchical clustering (HC) were implemented in order to visualize the classification trend between the stages. Seedlings contained more sinapic acid and vitamin C than older plants. Plants containing six or ten leaves had more ferulic acid and isorhamnetin than younger ones. Total phenolics, flavonols, hydroxycinnamic acids, quercetin and antioxidant capacity did not statistically differ between seedlings and stages with six or ten leaves and their concentrations were significantly higher than in stages with two or four leaves. PCA and HC confirmed the higher phytochemical similarity between seedlings and plants with six or ten leaves than plants with two or four leaves. Therefore, Chinese cabbage seedlings and plants with six or ten leaves should be preferred over plants with two or four leaves, which were ultimately shown to be of lesser nutritional quality.

Pereira C, Stefanucci A, Mollica A, Zengin G, Llorent-Martínez EJ, Castilho PC, Custódio L. Phenolic Profile, Toxicity, Enzyme Inhibition, In Silico Studies, and Antioxidant Properties of Cakile maritima Scop. (Brassicaceae) from Southern Portugal

Cakile maritima Scop. (sea rocket) is an edible halophyte plant with several ethnomedicinal uses. This work reports the chemical profile and bioactivities of food grade extracts from sea rocket organs. Toxicity was determined on mammalian cells, and phenolic profiling and the quantitation of the main metabolites were made by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Enzymatic inhibition was determined towards acetyl- and butyrylcholinesterase (AChE, BuChE), α-glucosidase, α-amylase, and tyrosinase. Docking studies were performed to tyrosinase, on the major metabolites, and samples were tested for antioxidant properties. Extracts were not toxic, were constituted mainly by flavonoids, and some compounds (roseoside and oleuropein) are here described for the first time in the species. The aerial organs' ethanol extract had relevant activity towards 2,2-diphenyl-1-picrylhydrazyl [DPPH, half maximal inhibitory concentration (IC50) = 0.59 mg/mL], and ferric-reducing activity power (FRAP, IC50 = 0.99 mg/mL). All samples were more active towards AChE than on BuChE. The ethanol fruits' extract inhibited α-glucosidase [2.19 mmol of equivalent of acarbose (ACAE)/g]. Samples were active against tyrosinase, especially the aerial organs' ethanol extracts [25.9 mg of equivalent of kojic acid (KAE)/g]. Quercetin and kaempferol glycosides fit well into the enzymatic pocket of tyrosinase. Our results suggest sea rocket as a candidate to be further explored as a source of bioactive products.

Antioxidant Components of Brassica Vegetables Including Turnip and the Influence of Processing and Storage on their Anti-oxidative Properties

Brassica vegetables, particularly turnip, contain many natural antioxidants. This review focuses on antioxidant components and the influence of different processing and storage conditions on antioxidant activities of some Brassica vegetables including turnip. Long storage times had an adverse effect on antioxidant value of turnip. Also, the activity of antioxidants in cruciferous vegetables could be influenced by antioxidant breakdown and leaching during cooking. Heat treatment has a major impact on the antioxidant activity of Brassica vegetables and it has been perceived minor antioxidant ability in processed vegetables compared with uncooked samples. Food processing operations in terms of blanching, canning, sterilizing and freezing, in addition to cooking methods perhaps can have a major influence on the yield, chemical structure and bioavailability of antioxidants in Brassica family. Cooking methods such as steaming and microwaving are proper methods for a short time. Consumption of raw or slightly blanched turnip is an appropriate way to maximize its health benefits.