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Curcumin's Biphasic Hormetic Response on Proteasome Activity and Heat‐Shock Protein Synthesis in Human Keratinocytes
Author(s) -
ALI REHAB E.,
RATTAN SURESH I. S.
Publication year - 2006
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1196/annals.1354.056
Subject(s) - curcumin , curcuma , chemistry , proteasome , pharmacology , hormesis , hsp70 , heat shock protein , proteasome inhibitor , zingiberaceae , biochemistry , traditional medicine , biology , medicine , oxidative stress , rhizome , gene
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 μM 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 μM the proteasome activity decreased to 46% of its initial value. Furthermore, the preincubation of human keratinocytes at 43°C for 1 h, followed by 24‐h treatment with 3 μM 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 μM. On the other hand, the level of the small hsp27 was unaffected by curcumin concentrations of 0.3–1 μM, while it decreased by 34% at 10 μM.