Preparation, Characterization, and Biological Potential of Nanoemulsion from Rosmarinus officinalis L. Essential Oil

Abstract

Essential oil from Rosmarinus officinalis (also known as rosemary essential oil) is used as traditional medicine and used as therapeutic in medicine, food, and cosmetic sectors. However, this oil is highly unstable, volatile, and prone to oxidation which limits its use. Thus, encapsulation is the better way to protect this oil from adverse conditions. The objective of this study was synthesis of rosemary essential oil (REO) based O/W (oil/water) nanoemulsions (designated as RNE) and evaluation of its biological potential. Physiological characterization was carried out using, UV, fluorescent, and FT-IR techniques. Various biological activities such as anticancerous, antidiabetic, and anti-inflammatory were also estimated. Pharmacokinetics studies on RNE were carried out. Encapsulation efficiency of RNE was found to be 92%. RNE nanoemulsions were spherical in shape with globule size, Z-Average (nm) size 220 nm, zeta potential ?11.33 mV, and polydispersity index was 0.47. RNE nanoemulsions were stable even after 50 days of storage at different temperatures. Antioxidant potential of RNE was conducted by various assays and IC50 were DPPH free radical scavenging activity: 21.53, nitric oxide radical scavenging activity: 26.66, hydroxyl radical scavenging activity: 32.69, ABTS radical scavenging activity: 33.05, and iron chelating assay: 38.78. Notable anticancer activity was observed with the percent cell viability of HeLa cells after treatment with RNE was 23% at higher concentration of 5 ?g. Antidiabetic study revealed that RNE inhibited ?-amylase in a concentration dependent manner, with 71% inhibition at its higher concentration of 250 ?g. RNE depicted maximum antibacterial activity against Bacillus subtilis at higher concentration of 300 ?g. Drug kinetic study revealed that nanoemulsions exhibited Korsmeyer�Peppas model. Based on this, the possible role of R. officinalis oil-based nanoemulsions in food, cosmetic, and pharma sectors has been discussed. � 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.