Preparation of phytol-loaded nanoemulsion and screening for antioxidant capacity

Abstract

The study prepared a nanoemulsion with a diterpenoid isoprenoid alcohol called phytol (PYT) and subsequently tested it for antioxidant capacity. For this, PYT-loaded nanoemulsion was prepared by phase inversion method and both PYT-containing nanoemulsion (PNE) and PYT-free nanoemulsion (PFNE) (2-16 µM) were tested for antiradical activity (DPPH•: 1,1-dipheny-picrylhydrazyl radical; ABTS•+: azino-bisethylbenzthiazoline-sulfonic acid; •OH: hydroxyl radical scavenging; NO•: nitrite oxide radical), lipid peroxidation (LP), reduction potential (RP), and inhibition of hemolysis (HL) in rat erythrocytes in comparison with an α-tocopherol analogue (Trolox - TRO - positive control). In addition, an in vivo test was performed with wildtype and deficient Saccharomyces cerevisiae strains using hydrogen peroxide (H2O2) as a stressor. Results suggest that PNE exhibited higher antioxidant than the PFNE. Increasing doses reveled antioxidant capacity in a dose-dependent manner. In the S. cerevisiae study, both PFNE- and PNE-treated groups exhibited decreased rates of survival with the highest doses, whichever in the presence of stressor increased the survival rates, which indicates antioxidative defense capacity of PYT. In this occasion, PNE exhibited prominent antioxidative defense in the presence of stressor rather than PFNE. In conclusion, PYT exhibited potential antioxidant activity but at high concentration it was toxic to the yeast cells. The production of PYT-nanoemulsions may be relevant to the pharmaceutical sciences.