Sulforaphane's Multifaceted Potential: From Neuroprotection to Anticancer Action

Abstract

Sulforaphane (SFN) is a naturally occurring compound found in cruciferous vegetables such as broccoli and cauliflower. It has been widely studied for its potential as a neuroprotective and anticancer agent. This review aims to critically evaluate the current evidence supporting the neuroprotective and anticancer effects of SFN and the potential mechanisms through which it exerts these effects. SFN has been shown to exert neuroprotective effects through the activation of the Nrf2 pathway, the modulation of neuroinflammation, and epigenetic mechanisms. In cancer treatment, SFN has demonstrated the ability to selectively induce cell death in cancer cells, inhibit histone deacetylase, and sensitize cancer cells to chemotherapy. SFN has also shown chemoprotective properties through inhibiting phase I metabolizing enzymes, modulating phase II xenobiotic-metabolizing enzymes, and targeting cancer stem cells. In addition to its potential as a therapeutic agent for neurological disorders and cancer treatment, SFN has shown promise as a potential treatment for cerebral ischemic injury and intracranial hemorrhage. Finally, the ongoing and completed clinical trials on SFN suggest potential therapeutic benefits, but more research is needed to establish its effectiveness. Overall, SFN holds significant promise as a natural compound with diverse therapeutic applications.

Keywords: antioxidant; cancer; chemotherapy; sulforaphane.

Figure 1

(A) Cruciferous vegetables are a rich source of glucoraphanin. (B) Upon chewing or chopping, the myrosinase enzyme present in plant tissues or intestinal flora catalyzes the breakdown of glucoraphanin to SFN (C₆H₁₁NOS₂). (C) SFN consequently becomes available to exert health benefits. (Chemical structures of SFN and Glucoraphanin were sourced from their respective Wikipedia pages: https://en.wikipedia.org/wiki/Sulforaphane and https://en.wikipedia.org/wiki/Glucoraphanin.) This illustration was made with Biorender.com (accessed on 8 August 2023).

Figure 2

Milestones in SFN applications. SFN was discovered in 1992. A remarkable milestone has been reached, from its applications as an antimicrobial agent, a neuroprotective agent, an anticancer agent, and anti-inflammatory agent to currently being under clinical trials for prostate cancer, breast cancer, and lung cancer, among others. This illustration was made with Biorender.com (accessed on 8 August 2023) [2,8,9,10,11,12].

Figure 3

Multifaceted Neuroprotective Effects of Sulforaphane (SFN) in Diverse Neurological Conditions. The central node represents sulforaphane, while six distinct branches emanate from it, each depicting a specific condition where SFN exerts its therapeutic impact. Texts attached to each branch elaborate on the molecular mechanisms and outcomes associated with SFN’s effects in these conditions. Red signifies reduction or decrease in effects. Green indicates an increase or improvement in effects. This illustration was made with Biorender.com (accessed on 8 August 2023) [24,25,26,27,28,29,30,31].

Figure 4

SFN’s Anticancer Effects Across Diverse Cancer Types. The various cancer types for which sulforaphane (SFN) exhibits potent anticancer properties. Red signifies reduction or decrease in effects. Green indicates an increase or improvement in effects. This illustration was made with Biorender.com (accessed on 8 August 2023) [44,70,71,72,73,74,75,76,77].

Figure 5

Conditions for which clinical trials with SFN have been registered. (Generated with data from ClinicalTrials.gov) (a) Conditions and respective numbers of clinical trials. The x-axis represents the number of studies that have recorded clinical trials with SFN and the conditions on the y-axis. (b) Breakdown of the phases of SFN clinical trials. This gives a general breakdown of how far SFN clinical trials have gone, with a majority of studies at the Phase 2 level.