Synthesize of nanoparticle-based surfactants containing Mentha piperita L. and Mentha pulegium L. essential oil in order to study the essential oil release and antioxidant activity

Essential Oils (EO) are highly volatile compounds. Encapsulation of EO into the nano-carrier leads to reduced EO volatility and oxidation, as well as increased therapeutic efficiency. The aim of this study was to synthesize a biocompatible nano-niosome containing Mentha piperita L. and Mentha pulegium L. EO and develop herbal-medicine system with suitable encapsulation efficiency. Hence, the amount and type of surfactant and also the amount of phospholipid were investigated in various niosomal formulations. Furthermore, the optimized formulation was introduced in terms of EO loading efficiency by investigating the acidity effect of hydrating buffer at 7.4 (neutral), 5.0 (acidic) and 9.0 (alkaline) pH. In addition, the EO release kinetic from the system was investigated in physiological conditions of normal (pH= 7.4, Temperature 37°C) and cancerous cells (pH= 5.4, temperature 42°C). Various niosomal formulations were prepared using thin-film method and the particle’s size, morphology, zeta potential and chemical interactions were characterized. Then, antioxidant activity of nanoparticles was evaluated by DPPH radical-scavenging assay. Results of the present study showed that the niosomal formulation containing soy phosphatidyl cholin, cholesterol, and tween-60 loaded with mint or Mentha pulegium EO (0.5 mg/mL),hydrated with PBS at pH= 9, had the highest loading efficiency. The EO loading efficiency for mint and Mentha pulegium was 61.36% and 74.31%, respectively. The investigation of morphology, size, and zeta showed particles to be spherical with the size less than 80 nm and anionic surface charge. EO release in acidic condition of cancerous cells and 42°C temperature was more than physiological conditions of normal cells, representing the sensitivity of synthesized formulation to pH and temperature. The FTIR analysis results showed that no interaction occurred between EO and noisome and the loading of EO into the niosomes did not make any changes in chemical nature of EO. In addition, the antioxidant activity of EO was very well preserved during the encapsulation.