Effect of turmeric, turmerin and curcumin on H2O2-induced renal epithelial (LLC-PK1) cell injury

Cell injury by oxidative stress is an important mechanism for renal epithelial cell destruction. This study observed the protective effect of turmeric and its constituents on H2O2-induced injury. Turmeric consists of a water soluble turmerin and lipid soluble curcumin with potent antioxidant properties. Confluent LLC-PK1 cells were labelled with H-3-arachidonic acid at 0.1 mu C/ml over 18 h and then further labelled with Cr-51. Turmeric (100 mu g/ml-0.1 mu g/ml), turmerin (800 ng/ml-0.8 ng/ml), curcumin (100 mu g/ml-0.1 mu g/ml), vitamin E (100 mu M) and 21-aminosteroid (20 mu M) were added and incubated for 3 h at 37 degrees C in 24-well plate. The adherent cells were washed and incubated for 3 h with 1.5 mM H2O2 at 37 degrees C. H-3-arachidonic acid release. Cr-51 release and lipid peroxidation by the thiobarbituric acid reaction was determined. Turmeric (100 mu g/ml) and curcumin (100 mu g/ml, 10 mu g/ml) gave as much protection as did vitamin E in both chromium release assay and lipid degradation while Turmeric (100 mu g/ ml) and curcumin (100 mu g/ml) gave comparable inhibition of lipid peroxidation. Turmerin and 21-aminosteroid showed no protection. These findings provide evidence that turmeric and curcumin provide protection against oxidative stress in a renal cell line. (C) 1997 Elsevier Science Inc.