Contribution of ferulic acid, γ-oryzanol and tocotrienols to the cardiometabolic protective effects of rice bran

Rice bran is an excellent nutritional source of bioactive compounds, including phytochemicals such as ferulic acid, γ-oryzanol, phytosterols and tocols. These bioactive molecules have shown cardiometabolic protection, such as anti-diabetic and anti-hypertensive effects, but more importantly, lipid lowering effects due to cholesterol synthesis downregulation and increased faecal excretion. Moreover, rice bran phytochemicals have been described to mitigate oxidative stress by increasing antioxidant enzymes and by reducing oxygen radical production, and to possess anti-inflammatory activity due to downregulation of NF-κβ activation and reduction of pro-inflammatory cytokines production. This review aims to update and summarize clinical and animal studies, describing the multifactorial activities of rice bran and the individual contribution of its main bioactive compounds, namely, γ-oryzanol, ferulic acid, phytosterols, triterpenic alcohols and tocotrienols. Technological factors affecting biological activities of the different rice bran-derived preparations are also discussed.