Apoptosis of adipose-derived stem cells induced by liposomal soybean phosphatidylcholine extract

Background: Recently, Phosphatidylcholine (PC) has been used as an off-label treatment for lipolysis injection, which is associated with inflammatory reaction due to sodium deoxycholate, an emulsifier, so that inflammation as side effect occurs in those patients. Liposome formulation from soybean lipid was thought to be a better and safer alternative. This study aimed to analyze the mechanism of Liposomal Soybean Phosphatidylcholine (LSPC) extract from Indonesian soybeans (containing 26% PC) to induce Adipose-derived Stem Cells (ASCs) death in vitro. Methods: Liposomes were prepared using thin film hydration method followed by a stepwise extrusion process to produce a small amount of 41.0-71.3 nm. Liposomal soybean phosphatidylcholine extract (LSPCE), liposomal purified PC (LPCC), and solution of PC+SD were used for comparison. Annexin V-fluorescein Isothiocyanate/ Propidium Iodide (FITC/PI) double staining by flow cytometry and also measurement of caspase-3 activity using ELISA were used to quantify the rate of apoptosis. ASCs viability was measured using MTT assay after induction with liposomes. Morphological changes were shown using a phase-contrast, inverted microscope and Transmission-Electron Microscope (TEM). Results: The flow cytometry results showed that cells treated with both LSPCE and LPCC showed increase in early apoptosis beginning at 6 hr after incubation, which was confirmed by caspase 3 measurement. MTT assay showed that both LSPCE and LPCC could decrease viability of cells. Cells treated with LSPCE and LPCC showed some rounded cells, which was an early sign of cell death. Cells treated with SD showed extensive membrane damage with necrosis features using TEM. Conclusion: The results above demonstrated that LSPCE induced apoptosis of ASCs.