Mitochondrial toxicity of selected natural compounds: in vitro assessment and in silico molecular docking and dynamics simulation

Prangos uechtritzii Boiss & Hausskn stands out for its rich bioactive constituents including prantschimgin (PRA), imperatorin (IMP), suberosin (SUB), adicardin (ADI), and oxypeucedanin hydrate (OPH) in the Apiaceae family. Although these molecules contribute to several biological activities, their mitochondrial toxicity were not illuminated in depth with the appropriate in vitro and in silico models. Cell viability studies investigated the cytotoxic activities of molecules in HepG2 cells by replacing glucose with galactose due to Warburg effects. Mitochondrial toxicity (mitotoxicity) parameters such as cellular adenosine triphosphate (ATP) and mitochondrial membrane potential (MMP) levels were assessed with cytotoxic concentrations of selected molecules. Molecular docking and dynamics studies were also conducted against mitochondrial electron transport chain (ETC) complexes (I-V) with selected compounds. In vitro results showed that PRA, SUB, and IMP reduced cell viability more in galactose media compared to high glucose media in a dose-dependent manner. PRA, IMP, and SUB decreased ATP levels and MMP, especially in the galactose medium. The in silico study revealed that PRA, IMP, and SUB might bind to complexes I-V at different levels. The docking study demonstrated that PRA had the highest binding potential with the complexes, higher than the standard ligands in some cases. The molecular dynamics (MD) simulation study showed that PRA formed stable complexes with complexes II, III, and IV. In addition, PRA was anticipated to remain inside the binding site of complex II most stably during the 230 ns simulation period. Our study suggests that PRA, IMP, and SUB exhibit mitotoxicity.