γ oryzanol

γ-Oryzanol was purchased from Wako Pure Chemical Industries (Japan). δ-, β-, γ-, and α-tocotrienol, and δ-, β-, γ-, and α-tocopherol were purchased from Merck Co., Ltd. (Kenilworth, NJ, USA). All solvents and chemicals used were either HPLC grade or analytical grade and were purchased commercially from Sigma Chemical Co. (St. Louis, MO, USA), Fluka Chemie GmBH(St. Gallen, Switzerland), Merck (Darmstadt, Germany), Invitrogen (Carlsbad, CA, USA), and Roche (Basel, Germany). A murine macrophage cell line (RAW 264.7), a human adenocarcinoma cell line (HT-29), and a colorectal carcinoma cell (HCT 116) were purchased from American Cell Culture Collection (Bethesda, MD, USA). Talcum was purchased from Union Science Co., Ltd. (Chiang Mai, Thailand). Eudragit^® NE30D and Eudragit^® L100 were supplied by Evonik industries AG (Essen, Germany). Colloidal silicon dioxide (Aerosil^®) was purchased from Bio-Chemical Technology Co., Ltd. (Prathum Thani, Thailand). Microcrystalline cellulose Avicel^® was purchased from Sigma-Aldrich (St. Louis, MO, USA).

To evaluate the preference for the HFD, γ-oryzanol (Wako Pure Chemical Industries, Osaka, Japan) was administrated to 8-week-old mice by gavage during the food choice test as previously described [14 (link), 17 (link)]. For the other experiments, an HFD (D12079B; Research Diets, New Brunswick, NJ, USA) containing 0.4% γ-oryzanol was manufactured as pellets. The components of the diet are shown in electronic supplementary material (ESM) Table 1. After 12 weeks of feeding, tissue was collected from the striatum and hypothalamus. The daily intake of γ-oryzanol, estimated from the mean food intake of the mice, was approximately 320 μg/g body weight. The doses of γ-oryzanol were determined as previously described [14 (link)]. The 5-aza-2′-deoxycytidine (5-aza-dC; Sigma-Aldrich, St Louis, MO, USA) was intraperitoneally injected (0.25 μg/g body weight) three times a week for 12 weeks [18 (link)].

Analytical-standard γ-oryzanol was purchased from Wako Pure Chemical Industries (Osaka, Japan). Standards of amino acids and GABA were obtained from Sigma-Aldrich (St. Louis, MO, USA). Certified HPLC-grade solvents n-hexane and isopropanol were purchased from Echo Chemical (Miaoli, Taiwan). All other reagents used for the extraction and analysis were analytical grade or purer and were purchased from Mallinckrodt Pharmaceuticals (Dublin, Ireland) and J. T. Baker Chemicals (Center Valley, PA, USA). Nutrient broth (NB) was purchased form Acumedia Manufacturers (Lansing, MI, USA).