Evaluating the Anti-Inflammatory and Antioxidant Effects of Broccoli Treated with High Hydrostatic Pressure in Cell Models

Abstract

Isothiocyanates (ITCs) are important functional components of cruciferous vegetables. The principal isothiocyanate molecule in broccoli is sulforaphane (SFN), followed by erucin (ERN). They are sensitive to changes in temperature, especially high temperature environments where they are prone to degradation. The present study investigates the effects of high hydrostatic pressure on isothiocyanate content, myrosinase activity, and other functional components of broccoli, and evaluates its anti-inflammatory and antioxidant effects. Broccoli samples were treated with different pressures and for varying treatment times; 15 min at 400 MPa generated the highest amounts of isothiocyanates. The content of flavonoids and vitamin C were not affected by the high-pressure processing strategy, whereas total phenolic content (TPC) exhibited an increasing tendency with increasing pressure, indicating that high-pressure processing effectively prevents the loss of the heat-sensitive components and enhances the nutritional content. The activity of myrosinase (MYR) increased after high-pressure processing, indicating that the increase in isothiocyanate content is related to the stimulation of myrosinase activity by high-pressure processing. In other key enzymes, the ascorbate peroxidase (APX) activity was unaffected by high pressure, whereas peroxidase (POD) and polyphenol oxidase (PPO) activity exhibited a 1.54-fold increase after high-pressure processing, indicating that high pressures can effectively destroy oxidases and maintain food quality. With regards to efficacy evaluation, NO production was inhibited and the expression levels of inducible nitric oxide synthase (iNOS) and Cyclooxygenase-2 (COX-2) were decreased in broccoli treated with high pressures, whereas the cell viability remained unaffected. The efficacy was more significant when the concentration of SFN was 60 mg·mL−1. In addition, at 10 mg·mL−1 SFN, the reduced/oxidized glutathione (GSH/GSSG) ratio in inflammatory macrophages increased from 5.99 to 9.41. In conclusion, high-pressure processing can increase the isothiocyanate content in broccoli, and has anti-inflammatory and anti-oxidant effects in cell-based evaluation strategies, providing a potential treatment strategy for raw materials or additives used in healthy foods.

Comprehensive Evaluation of the Bioactive Composition and Neuroprotective and Antimicrobial Properties of Vacuum-Dried Broccoli (Brassica oleracea var. italica) Powder and Its Antioxidants

“…The extraction process of the bioactive compounds of broccoli was conducted by means of the method proposed by Ke et al [ 63 ]. Fresh and dried broccoli samples were thoroughly dissolved in 80% aqueous methanol at a 1:5 and 1:10 w / v ratio, respectively, and agitated in an orbital shaker (OS-20, Boeco, Hamburg, Germany) at 250 rpm for 1 h, followed by centrifugation at 4193× g for 20 min at 4 °C (5804 R, Eppendorf, Hamburg, Germany).…”

Current Methods for the Extraction and Analysis of Isothiocyanates and Indoles in Cruciferous Vegetables

“…Applications of HPP in foods include the inactivation of microorganisms and enzymes and the increase in the shelf life of the products. Furthermore, the use of chemical preservatives is reduced [110]. After HPP on broccoli sprouts with 600 MPa, 85% of GLS were converted to ITCs [111] which suggested the inactivation of the ESP protein.…”

“…Moreover, the glucosinolate-myrosinase system in broccoli sprouts was not negatively affected. Two studies [110,112] have reported that the application of HHP at 400 MPa in red cabbage and broccoli generated the highest amounts of ITCs. Moreover, it was found that the activity of myrosinase increased after processing, indicating that the increase in ITCs content is related to the stimulation of myrosinase activity [110].…”

“…Two studies [110,112] have reported that the application of HHP at 400 MPa in red cabbage and broccoli generated the highest amounts of ITCs. Moreover, it was found that the activity of myrosinase increased after processing, indicating that the increase in ITCs content is related to the stimulation of myrosinase activity [110]. [118] High voltage electrical discharges are a non-thermal technique based on the electrical breakdown in water, while the air bubbles in water may accelerate the process.…”

Emerging Non-Thermal Food Processing Technologies: Editorial Overview

“…Besides, a research team conducted an attractive study on high-hydrostatic-pressure technology. They investigated the antioxidant and anti-inflammatory effects of broccoli treated with high hydrostatic pressure in cell models, and reported that this emerging nonthermal technology can enhance the isothiocyanate content of broccoli with antioxidant anti-inflammatory effects, providing an innovative strategy with which to develop healthy food products in the future [ 9 ]. Moreover, an insightful manuscript reported a significant improvement in the antioxidant capacity of puffed turmeric by the application of high hydrostatic pressure extraction.…”