The role of glucosinolates and their hydrolysis in pathogens, herbivores, and humans

Glucosinolates are characteristic in the Brassicaceae family of plants. In the past they have been implicated as toxic feeding deterrents for many herbivorous insects, but currently there is abundant research on their roles in health promotion in humans. Some insects are deterred by these plant-produced compounds, while others benefit from them. For example, Pieris butterflies are stimulated by glucosinolates for feeding purposes, but deterred from the same plant with cues from another chemical. In the case of humans, some perceive glucosinolates as a bitter taste, while other humans cannot perceive the bitterness in vegetables containing glucosinolates, including kale, cabbage, broccoli, arugula, and cauliflower. This can be problematic for health companies promoting food with these compounds, because genetics may be a significant element in the rejection of bitter glucosinolates by some humans. Glucosinolate bitterness perception is mainly studied in humans since their reactions to the taste can be communicated. In some studies, the variation in bitter perception of glucosinolates has been correlated to different allelic combinations of a particular bitter taste receptor gene, called TAS2R38. However, other studies have not found support for these correlations. The sensation of glucosinolates is most likely transduced as bitter perception as an adaptation to avoid toxic foods. However, these compounds are not toxic to humans if consumed at a reasonable concentration. This review article is intended to bring together current research on the health benefits of glucosinolate consumption in humans and how the perception of these compounds varies throughout human populations and how pathogens, insects, or other animals can be deterred by or attracted to glucosinolate compounds in plants.