Podophyllotoxin via SIRT1/PPAR /NF-κB axis induced cardiac injury in rats based on the toxicological evidence chain (TEC) concept

Abstract

BackgroundThe study of cardiotoxicity of drugs has become an important part of clinical safety evaluation of drugs. It is commonly known that podophyllotoxin (PPT) and its many derivatives and congeners are broad-spectrum pharmacologically active substances. Clinical cardiotoxicity of PPT and its derivatives has been raised, basic research on the mechanism of cardiotoxicity remains insufficient. PurposeIn present study, our group's innovative concept of toxicological evidence chain (TEC) was applied to reveal the cardiac toxicity mechanism of PPT by targeted metabolomics, TMT-based quantitative proteomics and western blot. MethodsThe injury phenotype evidence (IPE) acquired from the toxicity manifestations, such as weight and behavior observation of Sprague-Dawley rat. The damage to rat hearts were assessed through histopathological examination and myocardial enzymes levels, which were defined as Adverse Outcomes Evidence (AOE). The damage to rat hearts was assessed through histopathological examination and myocardial enzyme levels, which were defined as evidence of adverse outcomes.Overall measurements of targeted metabolomics based on energy metabolism and TMT-based quantitative proteomics were obtained after exposure to PPT to acquire the Toxic Event Evidence (TEE). The mechanism of cardiac toxicity was speculated based on the integrated analysis of targeted metabolomics and TMT-based quantitative proteomics, which was verified by western blot. ResultsThe results indicated that exposure to PPT could result in significant elevation of myocardial enzymes and pathological alterations in rat hearts. In addition, we found that PPT caused disorders in cardiac energy metabolism, characterized by a decrease in energy metabolism fuels. TMT-based quantitative proteomics revealed that the PPAR (Peroxisome proliferators-activated receptor) signaling pathway needs further study. It is worth noting that PPT may suppress the expression of SIRT1, subsequently inhibiting AMPK, decreasing the expression of PGC-1α, PPARα and PPARγ. This results in disorders of glucose oxidation, glycolysis and ketone body metabolism. Additionally, the increase in the expression of p-IKK and p-IκBα, leads to the nuclear translocation of NF-κB p65 from the cytosol, thus triggering inflammation. ConclusionThis study comprehensively evaluated cardiac toxicity of PPT and initially revealed the mechanism of cardiotoxicity,suggesting that PPT induced disorders of energy metabolism and inflammation via SIRT1/PPAR/NF-κB axis, potentially contributing to cardiac injury.