Medium 199

LLC-PK1 cells (ATCC, Manassas, VA, USA) were propagated in Medium 199 (Welgene, Gyeongsangbuk, Korea) containing 10% fetal bovine serum (Regeneration Biology, Ottawa, Canada) and 1% streptomycin-penicillin (Corning, Manassas, VA, USA). The typical growth conditions were set as 37 °C, 95% relative humidity, and 5% CO₂. A 100 mM stock solution of muscone (The Nature Network, Vestenbergsgreuth, Germany) and N-acetylcysteine (NAC; Abcam, Cambridge, UK) were prepared in dimethyl sulfoxide (DMSO; Santa Cruz Biotechnology, TX, USA). A 2 mM stock solution of cisplatin (Sigma-Aldrich, St. Louis, MO, USA) was prepared in autoclaved distilled water. The final proportion of DMSO was controlled to 0.1%, at which concentration cytotoxicity of vehicle (DMSO) and inhibition of cisplatin could not be observed in comparison to that in the non-treated cells. For experiments, LLC-PK1 cells were seeded into multi-well plates at a density of 3 × 10⁴ cells/cm² and incubated for 24 h. Next, the cells were treated with specific doses of compounds for 2 h and subsequently 20 µM cisplatin.