Biochemical, Biological, and Clinical Properties of γ-Oryzanol

Abstract

γ-Oryzanol is a complex mixture of ferulic acid esters of phytosterols and triterpene alcohols predominantly found in rice bran. It exhibits a wide range of biological activities, including antioxidant, anti-inflammatory, and lipid-lowering effects, as well as the ability to modulate cellular metabolic pathways in both in vitro and in vivo models. The composition and concentration of γ-oryzanol vary significantly among rice varieties and are influenced by genetic, environmental, and technological factors. Advances in extraction methods, including traditional solvent extraction and innovative approaches such as supercritical fluid extraction, have improved yield and purity, supporting its use in functional foods, nutraceuticals, and cosmetics. Current research in the biological, biomedical, and cosmetic fields is actively investigating γ-oryzanol’s mechanisms of action in metabolic regulation and inflammation, as well as developing advanced formulation strategies to enhance its antioxidant, skin-protective, and functional properties. These efforts aim to optimize its delivery and efficacy by addressing challenges related to poor water solubility and bioavailability, thereby expanding its role as a multifunctional bioactive compound. This review provides a comprehensive overview on γ-oryzanol, focusing on its extraction techniques, chemical characterization, and biological/pharmacological activities. Additionally, clinical trials investigating its efficacy and safety have been thoroughly dissected, offering valuable insights into its therapeutic potential in human populations.