In Vitro Immunostimulant Activity of Solid Self-nano Emulsifying Drug Delivery System (S-snedds)-loaded Propolis Extract on Raw 264.7 Macrophages

Abstract

Background: Propolis is known for its immunostimulant effects. However, its low solubility limits its therapeutic potential. To address this, Solid Self-Nano Emulsifying Drug Delivery Systems (S-SNEDDS) have been developed to improve the solubility and bioavailability of poorly soluble compounds like propolis. Objective: This study aims to evaluate the immunostimulant effects of S-SNEDDS propolis on RAW 264.7 macrophage cells in vitro. Methods: The S-SNEDDS propolis was prepared and characterized. Cell viabily assay was determined using the MTT method. The immunostimulant activity was assessed through phagocytosis activity using latex beads and nitric oxide (NO) production assays using the Griess method. Results: The characterization test of S-SNEDDS propolis demonstrated that all parameters met the standards for a nanoformulation, including %transmittance (99.724% ± 0.005), particle size (111.267 nm ± 0.462), polydispersity index (PDI) (0.328 ± 0.017), and zeta potential (-29.80 mV ± 0.7). The S-SNEDDS formulation demonstrated superior immunostimulant activity. At a concentration of 125 ppm, S-SNEDDS significantly increased NO production (5.85 ppm ± 0.008) and showed the highest phagocytosis index (0.923 ± 0.159) and capacity (49.75% ± 7.78) at 250 ppm. Conclusion: The S-SNEDDS propolis exhibits immunostimulant activity, outperforms propolis SNEDDS and propolis extract.