Broccoli or Sulforaphane: Is It the Source or Dose That Matters?

Abstract

There is robust epidemiological evidence for the beneficial effects of broccoli consumption on health, many of them clearly mediated by the isothiocyanate sulforaphane. Present in the plant as its precursor, glucoraphanin, sulforaphane is formed through the actions of myrosinase, a β-thioglucosidase present in either the plant tissue or the mammalian microbiome. Since first isolated from broccoli and demonstrated to have cancer chemoprotective properties in rats in the early 1990s, over 3000 publications have described its efficacy in rodent disease models, underlying mechanisms of action or, to date, over 50 clinical trials examining pharmacokinetics, pharmacodynamics and disease mitigation. This review evaluates the current state of knowledge regarding the relationships between formulation (e.g., plants, sprouts, beverages, supplements), bioavailability and efficacy, and the doses of glucoraphanin and/or sulforaphane that have been used in pre-clinical and clinical studies. We pay special attention to the challenges for better integration of animal model and clinical studies, particularly with regard to selection of dose and route of administration. More effort is required to elucidate underlying mechanisms of action and to develop and validate biomarkers of pharmacodynamic action in humans. A sobering lesson is that changes in approach will be required to implement a public health paradigm for dispensing benefit across all spectrums of the global population.

Sprouts and Microgreens: Trends, Opportunities, and Horizons for Novel Research

“…For plant-derived food, including sprouts, the lack of standardized protocols for the preparation and manipulation of the natural matrix is a crucial limitation. Sprouts, in fact, have been used in animal and human studies as a whole, in the form of extracts, and juices, using different amounts and inconsistent dietary regimens within the population appraised [241,242]. Variable conditions can impact bioavailability, while elusive information about liberation, absorption, distribution, metabolism, and excretion (LADME) phases of pharmacokinetics can complicate decisions as to when and for how long a treatment should be considered [243].…”

Measuring Sulforaphane and Its Metabolites in Human Plasma: A High Throughput Method

“…Glucoraphanin is an isothiocyanate found in cruciferous vegetables, particularly young broccoli (sprout and seeds) [16]. Glucoraphanin is converted into the active antioxidant, sulforaphane, in the gastrointestinal tract by myrosinase-catalyzed hydrolysis [16,17]. Sulforaphane is further metabolized into a number of other active metabolites (Figure 1).…”

Biomarker Exploration in Human Peripheral Blood Mononuclear Cells for Monitoring Sulforaphane Treatment Responses in Autism Spectrum Disorder

“…Myrosinase is also produced by the microflora of the gastrointestinal tract of all healthy humans 10,11 . For over two decades, evidence of the beneficial effects of SF has accumulated, extending from in vitro studies, to animal models, to a variety of clinical studies 6,[12][13][14][15] . Importantly, there are currently no drugs approved to treat the core symptoms of ASD, nor are there any studies using SF in genetic mouse models of ASD 16 .…”