Antiproliferative activity of prepared Aloe vera leaf skin extract-loaded essential oil nanoemulsions using Box-Behnken design

Aloe vera is being cultivated worldwide for its vast industrial applications in the pharmaceutical, cosmeceutical, and food sectors. In this work, the skin leaves of Aloe vera plant were used to extract bioactive components and load them into Satureja khuzistanica essential oil nanoemulsions (AvE-SKEO NE) to enhance delivery and cytotoxic effects against hepatocellular carcinoma (HepG2 cells). Box-Behnken response surface methodology (RSM) was used to optimize AvE-SKEO NE regarding particle size and PDI. Dynamic light scattering (DLS) and Transmission electron microscopy (TEM) were used to characterize the nanoemulsion. The nanoformulations with the minimum and maximum particle size (150 and 290 nm) and AvE content (2.5 and 5 mg) were screened for cytotoxicity activity against HepG2 cells. The results showed that the nanoformulations with minimum particle size and maximum AvE content showed the best cytotoxicity with IC₅₀ of 26.09 ± 2.46 µg/mL. Based on these results, the optimum formulation with the mean particle size of 169.08 ± 12.22 nm and AvE content of 5 mg was formulated and characterized. The optimal formulation's cytotoxicity decreased to 22.54 ± 5.16 µg/mL, which was only about two times lower than that of the well-known anticancer drug cisplatin (IC₅₀=12.00 ± 1.20 µg/mL). The stability of the optimized formulation was approved over 6 months, with no significant particle size changes. The results highlight the importance of Aloe vera to be explored as a new source for anticancer drug discovery using nanotechnology approaches.