STIMULATION OF THE STRESS-INDUCED EXPRESSION OF STRESS PROTEINS BY CURCUMIN IN CULTURED-CELLS AND IN RAT-TISSUES IN-VIVO

Curcumin, a major component of turmeric, a seasoning commonly used in Indian food, and a known antioxidant, anti-inflammatory and anti-carci nogenic agent, is a potent stimulator of the stress-induced expression of Hsp27, alpha B crystallin and Hsp70. When C6 rat glioma cells were exposed to arsenite (100 mu M for 1 h), CdCl2 (100 mu M for 1 h) or h eat (42 degrees C for 30 min) in the presence of 3-10 mu M curcumin, i nduction of the synthesis of all three proteins was markedly stimulate d, as detected by specific immunoassays, Western blot analysis and Nor thern blot analysis. A gel mobility shift assay revealed that curcumin prolonged the stress-induced activation of the heat shock element-bin ding (HSE-binding) activity of heat shock transcription factor (Hsf) i n the cultured cells. The stimulatory effect of curcumin on the respon ses to stress was also observed in BRL-3A rat liver cells and Swiss 3T 3 mouse fibroblasts. Induction of Hsp27, alpha beta crystallin and Hsp 70 in the liver and adrenal glands of heat-stressed (42 degrees C for 20 min) rats was also enhanced by prior injection of curcumin (20 mg/k g body weight). As curcumin is a potent inhibitor of arachidonic acid metabolism, it is suggested that the mechanism of the stimulation by c urcumin of the stress responses might be similar to that of salicylate , indomethacin and nordihydroguaiaretic acid.