Synthesis, characterization and cellular mineral absorption of nanoemulsions of Rhododendron arboreum flower extracts stabilized with gum arabic

To assess the cellular mineral uptake and oxidative stability of flower extract, a nanoscale gum arabic stabilized Rhododendron arboreum flower extract emulsion was formulated. Four different concentrations of flower extract (1-5%) were used for the optimization of the nanoemulsion. A significant (P < 0.05) difference was observed in average droplet size (43.51-55.87 nm) of the nanoemulsion. FTIR spectrum confirmed mainly C=C, aliphatic C-H, aliphatic and aromatic galacto-proteins, and polymeric-OH groups present in nanoemulsion. Smooth type of nanoemulsion was confirmed by inverted light microscopy. Ionic strength was evaluated and significant (P < 0.05) increase in particles size was attributed, whereas significant (P < 0.05) decrease in zeta potential was observed by increased NaCl concentration. Iron and calcium showed a non-significant difference in terms of mineral bioavailability. Calcium revealed significantly higher cellular uptake (52.11%) in comparison with iron (50.25%) and zinc (45.32%) during transwell assay. Higher cellular iron uptake unveiled a satisfactory amount of ferritin content