Improving the Health-Benefits of Kales (Brassica oleracea L. var. acephala DC) through the Application of Controlled Abiotic Stresses: A Review

Kale (Brassica oleracea L. var. acephala DC) is a popular cruciferous vegetable originating from Central Asia, and is well known for its abundant bioactive compounds. This review discusses the main kale phytochemicals and emphasizes molecules of nutraceutical interest, including phenolics, carotenoids, and glucosinolates. The preventive and therapeutic properties of kale against chronic and degenerative diseases are highlighted according to the most recent in vitro, in vivo, and clinical studies reported. Likewise, it is well known that the application of controlled abiotic stresses can be used as an effective tool to increase the content of phytochemicals with health-promoting properties. In this context, the effect of different abiotic stresses (saline, exogenous phytohormones, drought, temperature, and radiation) on the accumulation of secondary metabolites in kale is also presented. The information reviewed in this article can be used as a starting point to further validate through bioassays the effects of abiotically stressed kale on the prevention and treatment of chronic and degenerative diseases.

Agronomic and Metabolomic Side-Effects of a Divergent Selection for Indol-3-Ylmethylglucosinolate Content in Kale (Brassica oleracea var. acephala)

Brassica oleracea var. acephala (kale) is a cruciferous vegetable widely cultivated for its leaves and flower buds in Europe and a food of global interest as a “superfood”. Brassica crops accumulate phytochemicals called glucosinolates (GSLs) which play an important role in plant defense against biotic stresses. Studies carried out to date suggest that GSLs may have a role in the adaptation of plants to different environments, but direct evidence is lacking. We grew two kale populations divergently selected for high and low indol-3-ylmethylGSL (IM) content (H-IM and L-IM, respectively) in different environments and analyzed agronomic parameters, GSL profiles and metabolomic profile. We found a significant increase in fresh and dry foliar weight in H-IM kale populations compared to L-IM in addition to a greater accumulation of total GSLs, indole GSLs and, specifically, IM and 1-methoxyindol-3-ylmethylGSL (1MeOIM). Metabolomic analysis revealed a significant different concentration of 44 metabolites in H-IM kale populations compared to L-IM. According to tentative peak identification from MS interpretation, 80% were phenolics, including flavonoids (kaempferol, quercetin and anthocyanin derivates, including acyl flavonoids), chlorogenic acids (esters of hydroxycinnamic acids and quinic acid), hydroxycinnamic acids (ferulic acid and p-coumaric acid) and coumarins. H-IM kale populations could be more tolerant to diverse environmental conditions, possibly due to GSLs and the associated metabolites with predicted antioxidant potential.

Systematic integrated analyses of methylomic and transcriptomic impacts of early combined botanicals on estrogen receptor-negative mammary cancer

Dietary botanicals such as the cruciferous vegetable broccoli sprouts (BSp) as well as green tea polyphenols (GTPs) have shown exciting potential in preventing or delaying breast cancer (BC). However, little is known about their impact on epigenomic aberrations that are centrally involved in the initiation and progression of estrogen receptor-negative [ER(−)] BC. We have investigated the efficacy of combined BSp and GTPs diets on mammary tumor inhibition in transgenic Her2/neu mice that were administered the diets from prepubescence until adulthood. Herein, we present an integrated DNA methylome and transcriptome analyses for defining the early-life epigenetic impacts of combined BSp and GTPs on mammary tumors and our results indicate that a combinatorial administration of BSp and GTPs have a stronger impact at both transcriptome and methylome levels in comparison to BSp or GTPs administered alone. We also demonstrated a streamlined approach by performing an extensive preprocessing, quality assessment and downstream analyses on the genomic dataset. Our identification of differentially methylated regions in response to dietary botanicals administered during early-life will allow us to identify key genes and facilitate implementation of the subsequent downstream functional analyses on a genomic scale and various epigenetic modifications that are crucial in preventing ER(−) mammary cancer. Furthermore, our realtime PCR results were also found to be consistent with our genome-wide analysis results. These results could be exploited as a comprehensive resource for understanding understudied genes and their associated epigenetic modifications in response to these dietary botanicals.

A New Identification Method Reveals the Resistance of an Extensive-Source Radish Collection to Plasmodiophora brassicae Race 4

Raphanus sativus, an important cruciferous vegetable, has been increasingly affected by clubroot disease. Establishing a stable and accurate resistance identification method for screening resistant germplasms is urgently needed in radish. In this study, the influence of inoculum concentration, inoculation methods, and pH of the substrate on disease occurrence was studied. The result showed that the disease index (DI) was highest at 2 × 108 spores/mL, the efficiency of two-stage combined inoculation methods was higher than others, and pH 6.5 was favorable for the infection of P. brassicae. By using this new method, DIs of 349 radish germplasms varying from 0.00 to 97.04, presented significantly different levels of resistance. Analysis showed that 85.06% germplasms from China were susceptible to P. brassicae, whilst 28 accessions were resistant and mainly distributed in east, southwest, northwest, and south-central China. Most of the exotic germplasms were resistant. Repeated experiments verified the stability and reliability of the method and the identity of germplasm resistance. In total, 13 immune, 5 highly resistant and 21 resistant radish accessions were identified. This study provides an original clubroot-tolerance evaluation technology and valuable materials for the development of broad-spectrum resistant varieties for sustainable clubroot management in radish and other cruciferous crops.

Phenethyl Isothiocyanate, a Bioactive Agent for Gastrointestinal Health: A Review

The incidence of gastrointestinal diseases (cancer in particular) has increased progressively with considerable morbidity, mortality, and a high economic impact on the healthcare system. Dietary intake of natural bioactive phytochemicals showed to have cancer-preventing and therapeutic effects. This includes the cruciferous vegetable derivative phenethyl isothiocyanate (PEITC), a bioactive compound from watercress. PEITC antioxidant, anti-inflammatory and anti-cancer properties are of particular importance. This review summarizes the current knowledge on the role of PEITC as a potential natural nutraceutical or an adjuvant against oxidative/inflammatory-related disorders in the gastrointestinal tract. We also discuss the safe and recommended dose of PEITC. Besides, we establish a framework to guide the research and development of sustainable methodologies for obtaining and stabilizing this natural nutraceutical for industrial use. This is a topic that still needs more scientific development, but with the potential to lead to a viable strategy in the prevention of cancer and other associated diseases of the gastrointestinal tract.

Brassinin Inhibits Proliferation in Human Liver Cancer Cells via Mitochondrial Dysfunction

Brassinin is a phytochemical derived from Chinese cabbage, a cruciferous vegetable. Brassinin has shown anticancer effects on prostate and colon cancer cells, among others. However, its mechanisms and effects on hepatocellular carcinoma (HCC) have not been elucidated yet. Our results confirmed that brassinin exerted antiproliferative effects by reducing proliferating cell nuclear antigen (PCNA) activity, a proliferation indicator and inducing cell cycle arrest in human HCC (Huh7 and Hep3B) cells. Brassinin also increased mitochondrial Ca2+ levels and depolarized the mitochondrial membrane in both Huh7 and Hep3B cells. Moreover, brassinin generated high amounts of reactive oxygen species (ROS) in both cell lines. The ROS scavenger N-acetyl-L-cysteine (NAC) inhibited this brassinin-induced ROS production. Brassinin also regulated the AKT and mitogen-activated protein kinases (MAPK) signaling pathways in Huh7 and Hep3B cells. Furthermore, co-administering brassinin and pharmacological inhibitors for JNK, ERK1/2 and P38 decreased cell proliferation in both HCC cell lines more than the pharmacological inhibitors alone. Collectively, our results demonstrated that brassinin exerts antiproliferative effects via mitochondrial dysfunction and MAPK pathway regulation on HCC cells.

Association between maternal vegetable intake during pregnancy and allergy in offspring: Japan Environment and Children’s Study

The association between maternal diet during pregnancy and allergy in offspring remains contentious. Here, we examined the association between maternal intake of vegetables and related nutrients during pregnancy and allergic diseases in offspring at one year of age. A cohort of 80,270 pregnant women enrolled in the Japan Environment and Children’s Study were asked to respond to a food frequency questionnaire during pregnancy and the International Study of Asthma and Allergies in Childhood questionnaire at one year postpartum. The women were categorized into quintiles according to the energy-adjusted maternal intake of vegetables and related nutrients. Using the categorizations as exposure variables, the adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were determined for the allergic outcomes, including asthma, wheeze, atopic dermatitis, eczema, and food allergy, in the offspring per quintile at one year of age. Of the 80,270 participants, 2,027 (2.5%), 15,617 (19.6%), 3,477 (4.3%), 14,929 (18.7%), 13,801 (17.2%), and 25,028 (31.3%) children experienced asthma, wheeze, atopic dermatitis, eczema, food allergy, and some form of allergic disease, respectively. The aORs of each quintile of maternal vegetable intake for all allergic outcomes were close to 1.0 compared to the lowest quintile. The lowest aOR was found in the association of maternal cruciferous vegetable intake with asthma (aOR: 0.82, 95% CI: 0.70–0.96) and highest was found in the association of maternal total vegetable intake with atopic dermatitis (aOR: 1.17, 95% CI: 1.04–1.31). The risk of allergic outcomes for the various nutrients related to vegetable consumption was close to 1.0. The maternal intake of vegetables and various related nutrients during pregnancy had little or no association with any of the allergic outcomes, including asthma, wheezing, atopic dermatitis, eczema, and food allergy, in offspring at one year.