Effect of coenzyme Q10 encapsulation with different sterols on stability, antioxidant activity, and cellular properties of nanoliposomes

The present study focuses on optimizing the preparation conditions of coenzyme Q10 (CoQ10)-loaded liposomes (LPs), aiming to overcome the limitations of conventional LPs. Cholesterol, commonly used for LPs stabilization, prompts exploration of alternative phytosterols due to its health concerns. This study evaluates the optimal concentrations of cholesterol and β-sitosterol, along with CoQ10 by analyzing their effects on particle size and entrapment efficiency (EE) using response surface methodology. It further investigates how cholesterol and β-sitosterol impact key physicochemical attributes, including lipid oxidation stability, cellular adhesion property, and cellular antioxidant activity. Incorporating cholesterol led to increased particle size but decreased CoQ10-loaded LPs' EE. Conversely, β-sitosterol incorporation increased both particle size and EE. The optimal sterol, including cholesterol and β-sitosterol, and CoQ10 concentration was 0.605 and 0.150 mg/mL, respectively. Notably, significant differences between cholesterol and β-sitosterol exhibited in lipid oxidation stability and cellular antioxidant activity of CoQ10-loaded LPs prepared with optimal conditions (p < 0.05). Under heat treatment at 60 °C for 2 h, β-sitosterol-containing LPs suppressed malondialdehyde production approximately 15% more effectively than cholesterol-containing LPs. Moreover, β-sitosterol elevated cellular antioxidant activity by around 11% in Caco-2 monolayers compared to cholesterol. These findings highlight β-sitosterol's potential to enhance CoQ10-loaded LPs' physicochemical attributes, proposing applications for cholesterol-free, stable LPs with improved bioactivity in the food and pharmaceutical industries.