Characterisation of naturally occurring isothiocyanates as glutathione reductase inhibitors

Abstract

Glutathione reductase (GR), an essential antioxidant enzyme against oxidative stress, has become an attractive drug target for the development of anticancer and antimalarial drugs. In this regard, we evaluated the naturally occurring isothiocyanates as promising GR inhibitors and elucidated the mechanism of action. It was found that benzyl isothiocyanate (BITC) and phenethyl isothiocyanate (PEITC) inhibited yeast GR (yGR) and human GR (hGR) in a time-and concentration-dependent manner. The K i and k inact of BITC against yGR were determined to be 259.87 mM and 0.0266 min À1 , respectively. The GR inhibition occurred only in the presence of NADPH and persisted after extensive dialysis. The tandem mass spectrometric analysis revealed that Cys 61 rather than Cys 66 at the active site of yGR was mono-benzyl thiocarbamoylated by BITC. Inhibition of intracellular GR by BITC and PEITC in cultured cancer cells was also observed. BITC and PEITC were evaluated as competitive and irreversible inhibitors of GR.

The effects of morin and methotrexate on pentose phosphate pathway enzymes and GR/GST/TrxR enzyme activities: An in vivo and in silico study

“…[ 29 ] According to the previous studies regarding GR, the fluorophenylthiourea compounds displayed low µM IC 50 and K I values, with IC 50 values ranging from 8.85 ± 0.20 to 21.62 ± 0.27 µM and K I constants from 23.04 ± 4.37 to 59.97 ± 13.45 µM. [ 30 ] Li et al [ 31 ] investigated the time‐ and concentration‐dependent inhibition of yeast GR and human GR by phenethyl and benzyl isothiocyanates. The inhibiting effects of N ‐methylpyrrole derivatives on GR were described by Kocaoğlu et al [ 32 ] All the agents tested outperformed the potent GR inhibitor N , N ‐bis(2‐chloroethyl)‐ N ‐nitrosourea in terms of inhibitory efficacy, which researchers discovered.…”

Benzyl isothiocyanate improves the prognosis of Aspergillus fumigatus keratitis by reducing fungal load and inhibiting Mincle signal pathway

“…Redox homeostasis is essential for mitochondria, cells, and organisms to function properly ( Zorov et al, 2014 ). Previous studies have shown that BITC can disrupt redox reactions of cells through various mechanisms, such as inhibition of glutathione reductase and cytochrome c oxidase, as well as disruption of mitochondrial function, leading to cell death or apoptosis initiation ( Li et al, 2020 ; Henklewska et al, 2021 ). In our study, BITC induced ROS within fungi conidia in a concentration-dependent manner.…”

Long- term safety of Eruca sativa leaf ethanolic extract on Male Rats

“…While the rats treated with 6g/kg of BW show an early death at 14th day, and the percentage change in body weight for the other rats was signi cantly lower than other groups, which may re ect the toxicity at this dose. This result may be due to the cells being exposed to high levels of thiocynates resulting in glutathione reductase inhibitor which lead to an unbalance in cellular GSH/GR system causing depletion of cellular GSH, induce oxidative stress and cell death (Li et al 2020).…”

“…In addition the chemical components and mineral content of ESLE which stimulates the metabolic process which keep animal healthy(Khalil et al 2015;Tassi et al 2018). On the other hand, the decrease in the % body weight gain at 6g /kg may be attributed to high level of glucosinolates which lead to antinutrional effect, reduce protein digestibility and food consumption(Bjerg et al 1989) and/or decrease thyroid hormone production which lead to loss of weight(Felker et al 2016;Li et al 2020).…”