γ-Oryzanol is a potent DNA methyltransferases (DNMTs) inhibitor in the striatum of mice. γ-Oryzanol significantly inhibits the activities of DNMT1 (IC50=3.2 μM), DNMT3a (IC50=22.3 μM).
γ-Oryzanol significantly inhibits the activities of DNMT1 (IC50=3.2 μM), DNMT 3a (IC50=22.3 μM) and DNMT 3b (maximum inhibition 57%). In contrast, the inhibitory activity of Ferulic acid, a metabolite of γ-Oryzanol, is much lower than that of γ-Oryzanol. Furthermore, γ-Oryzanol acts as a partial antagonist against ERRγ, which primarily serves as a positive regulator for DNMT1 production, and consequently decreased the activity of DNMT1[1].
The brown rice-specific bioactive component γ-Oryzanol, a mixture of ferulic acid ester and several phytosterols, attenuates the preference for dietary fat via a decrease in hypothalamic endoplasmic reticulum (ER) stress. γ-Oryzanol ameliorates HFD-induced DNA hypermethylation of the promoter region of D2R in the striatum of mice. γ-Oryzanol might regulate levels of DNMTs in a striatum-specific manner. γ-Oryzanol partially decreases ERRγ activity (an approximately 40% reduction of the innate value). Oral administration of γ-Oryzanol to male mice by gavage significantly attenuates the preference for an HFD (93% of the values for vehicle-treated mice), resulting in an apparent attenuation of body weight gain[1].
[1]. Kozuka C, et al. Impact of brown rice-specific γ-oryzanol on epigenetic modulation of dopamine D2 receptors in brain striatum in high-fat-diet-induced obesity in mice. Diabetologia. 2017 Aug;60(8):1502-1511.