Optimized preparation of eugenol microcapsules and its effect on hepatic steatosis in HepG₂ cells

This study was aimed at evaluating the potential of peach gum (PG) and gelatin in the microencapsulation of eugenol and the intervention of eugenol microcapsules on hepatic steatosis in vitro. Response surface method (RSM) was used to optimize the encapsulation conditions of eugenol microcapsules. The microcapsules were characterized by scanning electron microscopy (SEM), dynamic Light Scattering (DLS), Fourier transform infrared spectroscopy (FT-IR) and release behavior in vitro was determined. The effect of eugenol microcapsules on free fatty acids (FFA) treated hepatocellular cells (HepG₂) cells was evaluated by oil red O staining and intracellular total cholesterol (TC) and triglyceride (TG) determination. The results showed that the optimal encapsulation conditions were as follows: the PG-gelatin ratio was 1.6:1.4, the core-wall ratio was 1.6:1.4, the pH was 4 and the emulsification speed was 9000 r/min. The optimized microcapsules were smooth spherical with a size of about 3.09 ± 0.58 μm and the encapsulation was confirmed by FT-IR. In vitro release behavior showed that eugenol microcapsules could be released stably in a neutral environment for 72 h. Oil red O staining showed that 50 and 100 μM eugenol microcapsules could significantly inhibit the lipid accumulation and reduce the TC and TG in steatotic HepG₂ cells induced by FFA. Therefore, PG and gelatin can be used as excellent carriers for the microencapsulation of volatile compounds in the field of biomedical industry, and eugenol microcapsules is a promising preparation for the treatment of nonalcoholic fatty liver disease (NAFLD).