The Integrative Role of Sulforaphane in Preventing Inflammation, Oxidative Stress and Fatigue: A Review of a Potential Protective Phytochemical

Abstract

Cruciferous vegetables hold a myriad of bioactive molecules that are renowned for possessing unique medicinal benefits. Sulforaphane (SFN) is one of the potential nutraceuticals contained within cruciferous vegetables that is useful for improving health and diseased conditions. The objective of this review is to discuss the mechanistic role for SFN in preventing oxidative stress, fatigue, and inflammation. Direct and indirect research evidence is reported to identify the nontoxic dose of SFN for human trials, and effectiveness of SFN to attenuate inflammation and/or oxidative stress. SFN treatment modulates redox balance via activating redox regulator nuclear factor E2 factor-related factor (Nrf2). SFN may play a crucial role in altering the Keap1/Nrf2/ARE pathway (an intricate response to many stimuli or stress), which induces Nrf2 target gene activation to reduce oxidative stress. In addition, SFN reduces inflammation by suppressing centrally involved inflammatory regulator nuclear factor-kappa B (NF-κB), which in turn downregulates the expression of proinflammatory cytokines and mediators. Exercise may induce a significant range of fatigue, inflammation, oxidative stress, and/or organ damage due to producing excessive reactive oxygen species (ROS) and inflammatory cytokines. SFN may play an effective role in preventing such damage via inducing phase 2 enzymes, activating the Nrf2/ARE signaling pathway or suppressing nuclear translocation of NF-κB. In this review, we summarize the integrative role of SFN in preventing fatigue, inflammation, and oxidative stress, and briefly introduce the history of cruciferous vegetables and the bioavailability and pharmacokinetics of SFN reported in previous research. To date, very limited research has been conducted on SFN’s effectiveness in improving exercise endurance or performance. Therefore, more research needs to be carried out to determine the effectiveness of SFN in the field of exercise and lifestyle factors.

A Short Overview of Changes in Inflammatory Cytokines and Oxidative Stress in Response to Physical Activity and Antioxidant Supplementation

“…One of the important pathways in this field is Nrf2-keap1 (nuclear factor erythroid 2-related factor 2-Kelch-like erythroid cell-derived protein with cap 'n' collar homology-associated protein 1) pathway. This pathway plays a major role in the expression of genes associated with maintaining cellular homeostasis and redox status, counteracting oxidizing molecules, and controlling cell functions such as apoptosis, differentiation, and cell proliferation [123,124]. In fact, under oxidative stress, Nrf2 within the nucleus interacts with antioxidant responsive element (ARE), leading to cell survival.…”

“…However, under hemostatic conditions, Nrf2 binds to the suppressor of the keap1 protein in the cytoplasm and is thus targeted by ubiquinine-dependent degradation in the proteasome [125,126]. On the other hand, many studies have recently concluded that Nrf2 can play an effective role in the prevention and treatment of diseases including exercise-induced organ damage and inflammation [122,123,126].…”

Nutraceutical Strategies for Suppressing NLRP3 Inflammasome Activation: Pertinence to the Management of COVID-19 and Beyond

“…Of key importance to our discussion is the fact that phase 2 induction boosts the expression of both thioredoxin and thioredoxin reductase, as well as that of glutathione peroxidase, capable of eliminating hydrogen peroxide [ 61 , 62 , 63 , 64 , 65 ]. Nutraceutical phase 2 inducers that have shown important clinical utility include lipoic acid, ferulic acid, melatonin, and sulforaphane [ 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 ].…”

Efficacy of Sulforaphane in Neurodegenerative Diseases

“…The biosynthesis of SFN occurs through a hydrolysis reaction that involves the myrosinase enzyme, present in plants, which together with the inactive form of epithiospecifier (ESP) protein leads to the formation of SFN. Conversely, the active form of ESP together with myrosinase leads to the synthesis of SFN nitrile [ 4 , 5 ].…”