Curcumin's biphasic hormetic response on proteasome activity and heat-shock protein synthesis in human keratinocytes.
Curcumin (diferuloylmethane), is a component of the yellow powder prepared from the roots of Curcuma longa (Zingiberaceae), also known as tumeric or turmeric. It is widely cultivated and used as a food ingredient in tropical areas of Asia and Central America. Treatment of mid-passage human epidermal keratinocytes with curcumin resulted in a biphasic hormetic dose-response with respect to proteasome activity. Curcumin treatment (up to 1 microM for 24 h) increased chymotrypsin-like activity by 46% compared to that in untreated keratinocytes. However, higher concentrations of curcumin were inhibitory, and at 10 microM the proteasome activity decreased to 46% of its initial value. Furthermore, the preincubation of human keratinocytes at 43 degrees C for 1 h, followed by 24-h treatment with 3 microM curcumin, led to an increase in heat-shock protein (hsp70 and hsp90) levels by 24% and 19%, respectively, and the effect was sustained at concentrations up to 10 microM. On the other hand, the level of the small hsp27 was unaffected by curcumin concentrations of 0.3-1 microM, while it decreased by 34% at 10 microM.
Ali
Rehab E
RE
Laboratory of Cellular Ageing, Danish Centre for Molecular Gerontology, Department of Molecular Biology, University of Aarhus, Denmark.
Rattan
Suresh I S
SI
D000328:Adult; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects / Q000502:physiology*; D003474:Curcumin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D000078404:Epidermal Cells; D005260:Female; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*
D006360:Heat-Shock Proteins; D046988:Proteasome Endopeptidase Complex; D003474:Curcumin