Background:

Daidzein is a soy isoflavone, which acts as a PPAR activator.

In 3T3-L1 adipocytes, Daidzein inverses the attenuation of adiponectin gene expression by co-culture, and these effects are inhibited by the PPAR-γ specific inhibitor. Daidzein attenuates the reduction of adiponectin expression in adipocytes, and a PPAR-γ specific inhibitor abrogated this effect. Direct activation of PPAR-α and-γ by Daidzein is confirmed by a luciferase reporter assay. In HEK293T cells, Daidzein significantly increases PPAR-α transcriptional activity in a concentration-dependent manner. Although an obvious dose-dependency is not observed in PPAR-γ transcriptional activity, Daidzein also significantly increases PPAR-γ transcriptional activity over a similar range of concentrations at which Daidzein enhanced PPAR-α transcriptional activity, with a maximum increase at 25 μM[1]. Daidzein is a soy isoflavone, which upregulates the expression of Abcg1, and it promotes axonal outgrowth in cultured hippocampal neurons via estrogen receptor signaling. Daidzein is a major component of soy with structural similarity to estrogen. It exerts an anti-inflammatory effect, lowers lipid levels, and increases mitochondrial biogenesis. As an activator of nuclear receptor peroxisome proliferator-activated receptors (PPARs), Daidzein enhances transcription of PPARs-dependent genes, including liver X receptors (LXRs, Nr1h gene family in mice). Incubation with different concentrations of Daidzein, from 5 to 100 μM, increases APOE transcriptional activity[2].

Treating Apoe KO mice with Daidzein increases Lxr and Abca1 gene expression at 1 month after stroke, showing that the absence of ApoE does not interfere with other cholesterol homeostasis genetic programs. Therefore, the findings suggest that Daidzein-induced ApoE upregulation is a critical component in fostering functional recovery in chronic stroke[2].

参考文献:
[1]. Sakamoto Y1, et al. The Dietary Isoflavone Daidzein Reduces Expression of Pro-Inflammatory Genes through PPARα/γ and JNK Pathways in Adipocyte and Macrophage Co-Cultures. PLoS One. 2016 Feb 22;11(2):e0149676.
[2]. Kim E, et al. Daidzein Augments Cholesterol Homeostasis via ApoE to Promote Functional Recovery in Chronic Stroke. J Neurosci. 2015 Nov 11;35(45):15113-26.