REDUCTION OF CISPLATIN TOXICITY IN CULTURED RENAL TUBULAR CELLS BY THE BIOFLAVONOID QUERCETIN

Quercetin (QC), a polyphenolic compound widely distributed in fruits a nd vegetables has recently gained interest due to its cisplatin (CP) s ensitizing properties in cancer cells. It is currently unknown: whethe r quercetin also increases the susceptibility of the kidneys to cispla tin toxicity. We studied the effects of various bioflavonoids on CF to xicity in an in vitro model of cultured tubular epithelial cells (LLC- PK1). Viability of LLC-PK1 cells. as assessed by lactate dehydrogenase (LDH) release and MTT-test. was affected by CP(100-400 mu M) in a tim e and dose dependent fashion. Pretreatment of cells with QC for 3 h si gnificantly reduced the extent of cell damage. The protective activity of QC was concentration dependent, starting at 10-25 mu M and reachin g a plateau between 50 and 100 mu M. Other bioflavonoids (catechin. si libinin, rutin) did not diminish cellular injury, even at higher conce ntrations (100-500 mu M). Quercetin itself showed some intrinsic cytot oxicity at concentrations exceeding 75 mu M. Our data indicate that qu ercetin reduces cisplatin toxicity in cultured tubular epithelial cell s. The exact mechanism of protection is unclear, though scavenging of free oxygen radicals may play an important role.