Concept: Cruciferous vegetables
Cells lining the respiratory tract are equipped with mechanisms that dampen the effects of oxidative stress. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a mediator involved in regulating oxidative stress. Recent data indicate Nrf2 also controls expression of secretory leukocyte protease inhibitor (SLPI). Sulforaphane (SFN), an isothiocyanate found in cruciferous vegetables, enhances Nrf2 activity. Therefore, we hypothesized that SFN supplementation induces SLPI secretion in the nasal mucosa in an Nrf2 dependent manner. Healthy nonsmoking adults ingested SFN-containing broccoli shake homogenate (BSH) for 3 consecutive days. Nasal lavage fluid (NLF) was collected before and after BSH ingestion and analyzed for SLPI protein levels. In follow up in vitro experiments, differentiated primary nasal epithelial cells were used to evaluate the relationship between SFN, Nrf2, and SLPI. Epithelial cells were transduced with Nrf2-specific shRNA to examine the regulatory role of Nrf2 on SLPI expression. Supplementation with BSH significantly increased SLPI levels in NLF. SFN supplementation in vitro significantly enhanced SLPI secretion and these effects were significantly decreased in cells transduced with Nrf2-specific shRNA. Our data support a relationship between nutritional supplementation, Nrf2 activation, and SLPI secretion. Therefore, ingestion of SFN-containing foods has therapeutic potential to augment SLPI expression in the nasal mucosa.
Higher intakes of cruciferous vegetables or their constituents have been shown to lower inflammation in animal studies. However, evidence for this anti-inflammatory effect of cruciferous vegetable consumption in humans is scarce.
Evidence shows cruciferous vegetables exhibit chemoprotective properties, commonly attributed to their rich source of isothiocyanates. However, epidemiological data examining the association between cruciferous vegetable intake and colorectal neoplasms have been inconclusive. This meta-analysis examines the epidemiological evidence to characterize the association between cruciferous vegetable intake and risk of developing colorectal neoplasms. Thirty-three articles were included in the meta-analysis after a literature search of electronic databases. Subgroup analysis for individual cruciferae types (n = 8 studies) and GST polymorphism (n = 8 studies) were performed. Pooled adjusted odds ratios (ORs) comparing highest and lowest categories of dietary pattern scores were calculated. Results show a statistically significant inverse association between cruciferous vegetable intake and colon cancer [OR = 0.84; 95% confidence interval (CI): 0.72-0.98; P value heterogeneity < 0.001]. Broccoli in particular exhibited protective benefits against colorectal (CRC) neoplasms (OR = 0.80; 95% CI: 0.65-0.99; P value heterogeneity = 0.02). Stratification by GST genotype reveals that the GSTT1 null genotype confers a reduction in CRC risk (OR = 0.78; 95% CI: 0.64-0.95; P value heterogeneity = 0.32). This study provides support to the hypothesis that cruciferous vegetable intake protects against cancer of the colon. This study also demonstrates the significance of gene-diet interactions and the importance of assessing individual cruciferous vegetables.
Sulforaphane (SFN), a natural compound occurring in cruciferous vegetables, has been known for years as a chemopreventive agent against many types of cancer. Recently, it has been investigated as an antioxidant and anti-aging agent, and interesting conclusions have been made over the last decade. SFN demonstrated protective effects against ultraviolet (UV)-induced skin damage through several mechanisms of action, for example, decrease of reactive oxygen species production, inhibition of matrix metalloproteinase expression, and induction of phase 2 enzymes. SFN used as a protective agent against UV damage is a whole new matter, and it seems to be a very promising ingredient in upcoming anti-aging drugs and cosmetics.
Glycation, an endogenous process that leads to the production of advanced glycation end products (AGEs), plays a role in the etiopathogenesis of different neurodegenerative diseases such as Alzheimer’s disease (AD). Methylglyoxal is the most potent precursor of AGEs and high levels of methylglyoxal have been found in the cerebrospinal fluid of AD patients. Methylglyoxal may contribute to AD both inducing extensive protein cross-linking and as mediator of oxidative stress. Aim of this study was to investigate the role of sulforaphane, an isothiocyanate found in Cruciferous vegetables, in counteracting methylglyoxal induced damage in SH-SY5Y neuroblastoma cells. Data demonstrated that sulforaphane protected cells against glycative damage by inhibiting the activation of caspase-3 enzyme, reducing the phosphorylation of MAPK signaling pathways (ERK1/2, JNK, and p38), reducing oxidative stress and increasing intracellular GSH levels. For the first time we demonstrated that sulforaphane enhanced methylglyoxal detoxifying system increasing the expression and activity of glyoxalase I. Sulforaphane modulated brain derived neurotrophic factor and its pathway, whose dysregulation is related to AD development. Moreover, sulforaphane was able to revert the reduction of glucose uptake caused by methylglyoxal. In conclusion, sulforaphane demonstrated a pleiotropic behavior thanks to its ability to act on different cellular targets, suggesting its potential role in preventing/counteracting multifactorial neurodegenerative diseases such as AD.
Sulforaphane, a naturally occurring cancer chemopreventive, is the hydrolysis product of glucoraphanin, the main glucosinolate in broccoli. The hydrolysis requires myrosinase isoenzyme to be present in sufficient activity; however, processing leads to its denaturation and hence reduced hydrolysis. In this study, the effect of adding mustard seeds, which contain a more resilient isoform of myrosinase, to processed broccoli was investigated with a view to intensify the formation of sulforaphane. Thermal inactivation of myrosinase from both broccoli and mustard seeds was studied. Thermal degradation of broccoli glucoraphanin was investigated in addition to the effects of thermal processing on the formation of sulforaphane and sulforaphane nitrile. Limited thermal degradation of glucoraphanin (less than 12%) was observed when broccoli was placed in vacuum sealed bag (sous vide) and cooked in a water bath at 100°C for 8 and 12 min. Boiling broccoli in water prevented the formation of any significant levels of sulforaphane due to inactivated myrosinase. However, addition of powdered mustard seeds to the heat processed broccoli significantly increased the formation of sulforaphane.
Kale (Brassica oleracea var. acephala) is a cruciferous vegetable, characterized by leaves along the stem, which, in recent years, have gained a great popularity as a ´superfood´. Consequently, in a popular culture it is listed in many ´lists of the healthiest vegetables´. Without the doubt, a scientific evidence support the fact that cruciferous vegetables included in human diet can positively affect health and well-being, but remains unclear why kale is declared superior in comparison with other cruciferous. It is questionable if this statement about kale is triggered by scientific evidence or by some other factors. Our review aims to bring an overview of kale’s botanical characteristics, agronomic requirements, contemporary and traditional use, macronutrient and phytochemical content and biological activity, in order to point out the reasons for tremendous kale popularity.
Sulforaphane is a phytochemical that is usually found in cruciferous vegetables and is known to have a depressive effect on gastric cancer. Preliminary investigations showed that the sulforaphane concentration in broccoli (Brassica oleracea var. italica) florets increased under anoxia. Therefore, in the present study, we examined the effect of different atmospheric conditions on the sulforaphane concentration in broccoli and also tested whether there are concurrent effects on the concentration of ethanol, which is an unfavorable byproduct of fermentation. The sulforaphane concentration in broccoli florets was significantly elevated by 1.9- to 2.8-fold after 2 d of storage under hypoxia at ca. 0% O2 and ca. 24% CO2 at 20°C, whereas no such increase was observed following storage under normoxia at ca. 0% O2 without CO2 at 20°C. Furthermore, after 2 d, the sulforaphane concentration under hypoxia was 1.6- to 2.3-fold higher than that under normoxia. These results suggest that storage under hypoxia with high CO2 levels can elevate the sulforaphane concentration in broccoli florets. However, the elevated sulforaphane concentration could not be maintained beyond 2 d. There was no significant difference in the concentration of ethanol between florets that were stored under hypoxia with/without CO2 or normoxia at 2 d. However, the ethanol concentrations inside the pouches significantly increased between 2 d and 7 d. These findings indicate that the quality of broccoli florets can be improved through storage under hypoxia with high CO2 levels at 20°C for 2 d.
A photochemically induced fluorescence based flow-through optosensor for screening of nitenpyram residues in cruciferous vegetables
- Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment
- Published almost 2 years ago
One of the most used agrochemicals in agricultural production, nitenpyram (NTP), has been determined by using a flow-through optosensing device based on Photochemically Induced Fluorescence (PIF) detection. The combination of both methodologies allows, on one hand, a quick on-line photodegradation of NTP and, on the other hand, the preconcentration, quantification and desorption of the fluorescent photoproduct generated when retained on Sephadex QAE-A25 as solid support, which was monitored at 295 and 362 nm for excitation and emission, respectively. The proposed analytical method presents a detection limit of 500 pg mL-1by using Multicommutated Flow Injection Analysis (MCFIA). Recovery experiments were carried out in different kinds of cruciferous vegetables at or below the maximum residue limit (MRL) established in Japan, demonstrating that this method combines advantages of simplicity, high sensibility and high selectivity, fulfilling the requirements for its application in quality control. Results obtained in the analysis of real samples were in good agreement with those provided by a reference HPLC method.
Several lines of evidence suggest that the consumption of cruciferous vegetables is beneficial to human health. Yet, underlying mechanisms and key molecular targets that are involved with achieving these benefits in humans are still not fully understood. To accelerate this research, we conducted a human study to identify potential molecular targets of crucifers for further study. This study aimed to characterize plasma metabolite profiles in humans before and after consuming fresh broccoli sprouts (a rich dietary source of bioactive sulforaphane).