Oropharyngeal administration of the GSTP inhibitor, TLK117, at a time when fibrosis is already apparent, attenuated bleomycin- and AdTGFβ-induced remodeling, α-SMA, caspase activation, FAS S-glutathionylation, and total protein S-glutathionylation. Four hours after administration of 50 mg/kg TLK117, GSTP activity is strongly decreased and remains decreased by about 60% for at least 24 hours.