Physiological relevance of covalent protein modification by dietary isothiocyanates

Abstract

Isothiocyanates (ITCs), naturally occurring in abundance in cruciferous vegetables, are the most well-studied organosulfur compounds having an electrophilic reactivity. ITCs have been accepted as major ingredients of these vegetables that afford their health promoting potentials. ITCs are able to modulate protein functions related to drug-metabolizing enzymes, transporters, kinases and phosphatases, etc. One of the most important questions about the molecular basis for the health promoting effects of ITCs is how they modulate cellular target proteins. Although the molecular targets of ITCs remains to be validated, dietary modulation of the target proteins via covalent modification by ITCs should be one of the promising strategies for the protection of cells against oxidative and inflammatory damage. This review discusses the plausible target proteins of dietary ITCs with an emphasis on possible involvement of protein modification in their health promoting effects. The fundamental knowledge of ITCs is also included with consideration of the chemistry, intracellular behavior, and metabolism.

Phenethyl isothiocyanate activates leptin signaling and decreases food intake

“…To determine the modification site by PEITC, the native and PEITC-treated PTP1B were digested with V8 and trypsin and then analyzed by ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) [ 27 ]. However, we could not observe any modified peptides, probably due to instability of the thiocarbamoyl adduct [ 53 ]. Recently, we found that safranal, a doubly unsaturated aldehyde isolated from saffron, effectively inhibited PTP1B by covalent addition to the reactive cysteine through a Michael reaction [ 38 ].…”

Secondary sulfur metabolism in cellular signalling and oxidative stress responses

“…It can be hypothesized that the effects of isothiocyanate is due to either the activation of specific signalling proteins, or the stimulation of cellular responses to the increased ROS and NO levels, or both. In animal systems the proposed modes of action for ingested isothiocyanates include direct binding to reactive thiol groups of proteins (Nakamura et al, 2018). Whether such mechanisms also hold true in plants will need further investigation.…”

Pseudosciaena crocea roe protein‐stabilized emulsions for oral delivery systems: In vitro digestion and in situ intestinal perfusion study

“…Emulsion-based delivery systems are designed to encapsulate various types of active ingredients including vitamins, carotenoids, flavonoids, polyphenols, and polyunsaturated fatty acids (Facchi et al, 2016;McClements et al, 2016;Shao, Qiu, Xiao, Zhu, & Sun, 2017). BITC can potentially inhibit the growth of cancer cells and has antibacterial activity (Nakamura, Abekanoh, & Nakamura, 2018). However, BITC is poorly water soluble and is unstable in alkaline or high temperature environments (Kawakishi & Namiki, 1969).…”