L-Buthionine-(S,R)-sulfoximine is an irreversible inhibitor of γ-glutamylcysteine synthetase (Ki = 25 ?M).1 It inhibits the proliferation of ZAZ and M14 melanoma cells, as well as A2780 ovarian and MCF-7 breast cancer cells (IC50s = 4.9, 18, 8.5, and 26.5 ?M, respectively).2 L-Buthionine-(S,R)-sulfoximine (100?M) induces ferroptosis in A172 and T98G glioblastoma cells.3 It increases reactive oxygen species (ROS) levels in HeLa cells when used at a concentration of 10 ?M. L-Buthionine-(S,R)-sulfoximine (1 mM), in combination with methylglyoxal, induces apoptosis of bovine aortic endothelial cells (BAECs).4 It increases the number of eye spots in the retinal pigment epithelium, an indicator of DNA deletions, in mouse pups when administered to pregnant dams at concentrations of 2 and 20 mM in the drinking water.5 L-Buthionine-(S,R)-sulfoximine decreases cysteine and glutathione (GSH) levels in fetal mice when administered to pregnant dams.
1.Griffith, O.W.Mechanism of action, metabolism, and toxicity of buthionine sulfoximine and its higher homologs, potent inhibitors of glutathione synthesisJ. Biol. Chem.257(22)13704-13712(1982) 2.Fruehauf, J.P., Zonis, S., al-Bassam, M., et al.Selective and synergistic activity of L-S,R-buthionine sulfoximine on malignant melanoma is accompanied by decreased expression of glutathione-S-transferasePigment Cell Res.10(4)236-249(1997) 3.Hayashima, K., and Katoh, H.Expression of gamma-glutamyltransferase 1 in glioblastoma cells confers resistance to cystine deprivation-induced ferroptosisJ. Biol. Chem.298(3)101703(2022) 4.Takahashi, K., Tatsunami, R., Oba, T., et al.Buthionine sulfoximine promotes methylglyoxal-induced apoptotic cell death and oxidative stress in endothelial cellsBiol. Pharm. Bull.33(4)556-560(2010) 5.Reliene, R., and Schiestl, R.H.Glutathione depletion by buthionine sulfoximine induces DNA deletions in miceCarcinogenesis27(2)240-244(2006)