 - Detoxification of platinum derivatives The glutathione GSH conjugation pathway is involved in detoxification of platinum derivatives and decreases their cytotoxicity by inhibiting the formation of DNA adducts. Conjugation to GSH is ensured by glutathione-S-transferases GSTs, which constitute a multigenic family of enzymes involved in phase II metabolism that inactivate electrophilic molecules by conjugating them to glutathione, thereby promoting their elimination. GSTP1 is particularly involved in the conjugation of platinum derivatives. Elimination of glutathione conjugates then involves membrane transporters. These conjugates can be expelled from target tumour cells and then eliminated, essentially in the urine, by efflux membrane transporters, particularly MRP2 Sun et al., 2009. Two other enzymes, thiopurine S-methyltransferase TPMT and catechol O-methyltransferase, have been reported to be associated with increased toxicity of cisplatin when their activity is decreased Ross et al., 2009. 