Upregulation of Nrf2–p300 mediates anti-inflammatory effects of curcumin in microglia by downregulating p65–p300

Abstract

ABSTRACTCurcumin (CUR) is a hydrophobic polyphenol derived from the rhizome of Curcuma longa. CUR confers protection in various pathological conditions, including many brain-related diseases, such as cerebral ischemia, intracerebral hemorrhage, or Alzheimer’s disease, and these effects have been attributed to its anti-inflammatory and anti-oxidative properties. In the present study, we found CUR induced the nuclear translocation of nuclear factor E2-related factor 2 (Nrf2) in microglia, brain macrophage, and thus upregulated genes downstream of antioxidant response element, such as heme oxygenase 1, NAD(P)H:quinone oxidoreductase 1, glutamate-cysteine ligase modifier subunit, and ferritin light chain, and simultaneously downregulated lipopolysaccharide-induced inducible nitric oxide synthase expression. We showed that the anti-inflammatory effect of CUR in microglia is connected with its anti-oxidative effect in that CUR promotes Nrf2–p300 binding at the expense of p65–p300 binding. Since CUR is a dietary spice that is eaten on a daily basis, it appears that CUR could be used therapeutically to induce anti-oxidative effect and simultaneously ameliorate inflammatory conditions via up–downregulation of related genes.