Extraction of Vitamin E Isomers from Palm Oil: Methodology, Characterization, and in Vitro Anti-Tumor Activity.

ABSTRACT

Vitamin E refers to a family of eight tocopherols (T) and tocotrienol (T3) isomers. Due to the unique pharmacological and anticancer activity of the individual isomers, there is a need to extract and separate the individual T3 isomers from T/T3 rich fractions of palm oil. The objective of the present study was to present a detailed protocol for the extraction of gram quantities of vitamin E isomers from a T3 rich fraction (Tocotrol™) that was obtained from palm oil, by column chromatography using a binary hexaneEtOAc (1-12%) phase system. The chemical integrity and identity of the extracted isomers was confirmed by TLC, HPLC, 1H-NMR, and Raman analysis. To evaluate their anticancer activity, vitamin E isomers were first entrapped into nanoemulsions and then tested against a panel of breast and pancreatic cancer cell lines. Nanoemulsions were prepared by the solvent evaporation technique. They had an average droplet size between 156-200 nm. In confirmation to what has been reported in the literature, γ-T3 and δ-T3 isomers were found to be significantly more active against tumor cells than the α-T and α-T3 isomers. The current study has demonstrated the feasibility of extracting the individual vitamin E isomers at high yields from natural sources while maintaining their chemical integrity and pharmacological activity.