Unveiling the vitamin E profile in rice bran extracellular vesicles: evaluation of extraction and preparation methods

Extracellular vesicles (EVs) are nanoscale entities secreted by various cells, encapsulating various nucleic acids and proteins that play important roles in cellular activities. Although rice bran is known for its richness in phytochemicals such as tocopherol and tocotrienol, the distribution of these compounds within EVs has not been extensively studied. The objective of this study was to detect and analyze the presence of vitamin E in EVs extracted from rice bran. We investigated several EV extraction methods, including rotation, vortex mixing, and ultrasonication, followed by post-extraction techniques such as ultracentrifugation, ultrafiltration, and lyophilization. Vitamin E in the EVs from rice bran was analyzed using LC-FLD. This study is the first to identify tocopherol and tocotrienol in rice bran-derived EVs. Our results indicate that ultracentrifugation followed by rotation is the most effective method for the preparation of rice bran-derived EVs. Notably, the vitamin E profile in EVs varies depending on the preparation method and differs from that in rice bran extracts. The pronounced presence of vitamin E in EVs suggests unique pharmacokinetics and underscores the potential of EVs as carriers for drug delivery systems. This study not only confirms the presence of vitamin E in EVs, but also underscores the potential of EVs and their phytochemical content for therapeutic applications.