Preparation, characterization and in-vitro bioassays of nanoemulsions from palmarosa ( Cymbopogon martinii ) essential oil

Cymbopogon martinii essential oil (Palmarosa essential oil, PRO) has a wide range of applications in food, medicine, and cosmetics. Because of its hydrophobicity, instability, and volatility, the best option to safeguard this oil is to encapsulate it using nanoemulsion technology. In this work, we synthesize O/W (oil/water) nanoemulsions from C. martini essential oil and analyze their biological activity. The study uses co-surfactants like ethanol and surfactants like tween 80 and sodium dodecyl sulfate to create O/W nanoemulsions. The nanoemulsions were investigated using UV, fluorescence, and FT-IR fingerprinting techniques in addition to parameters such as pH and conductivity. Additionally, the study explored the biological effects of the nanoemulsions, including their antibacterial, anti-inflammatory, anticancer, and anti-diabetic capabilities. The pharmacokinetics of drug release was also examined. By using GC-FID analysis, it has been determined that geraniol is the primary component of PRO. The concentrations of total phenolic, total flavonoid, and total condensed tannin were found to be 2.91 mg/g GAE, 9.29 mg/g RE, and 3.78 mg/g VAE, respectively. Palmarosa essential oil nanoemulsions (PNE) were discovered to have 93.24% encapsulation efficiency. The nanoemulsions remained stable and spherical even after 50 days of storage. PNE was synthesized with a mean diameter of 460.55 ± 98.65 nm, a polydispersity index (PDI) value of 0.45 ± 0.04, and a zeta potential measurement of 0.1711 ± 0.05 mV. According to a drug kinetic analysis, PNE displayed a first-order model with an R2 value of 0.930. PNE revealed a dose-dependent 92% inhibition of α-amylase. Additionally, PNE demonstrated potent anti-bacterial activity against the investigated pathogens that varied from 38% to 94%. In the same way, PNE demonstrated potent anti-fungal efficacy against the studied fungal infections, with a range of 50–95%. Anticancer research showed that the PNE-containing cells had a percent viability of 21.29% after 24 hours and 14.92% after 48 hours, respectively. The article explores the possible applications of nanoemulsions made from palmarosa essential oil in the cosmetic, food, and medicinal sectors.