Patulin induces ROS-dependent cardiac cell toxicity by inducing DNA damage and activating endoplasmic reticulum stress apoptotic pathway.

Patulin (PAT) is one of the mycotoxins commonly found in agricultural products and fruits, and has obvious toxic effects on animals and humans. PAT has been found to cause myocardial toxicity and oxidative damage, but the mechanism of myocardial toxicity remained to be elucidated. We investigated the toxic effects and potential mechanisms of PAT on human cardiomyocytes and explored the effects of reactive oxygen species (ROS) on them. The study showed that treatment with PAT for 24 h decreased cell viability and superoxide dismutase (SOD) activity, and increased ROS and lactate dehydrogenase (LDH) levels. Moreover, in addition to detecting increased γ-H2AX expression and observing nuclear damage, the comet assay also showed increased DNA tail distance in the PAT-treated group, followed by an increase in phosphorylation of the p53 protein and p21 protein expression, and a decrease in CDK1 and Cyclin B1 protein expression, and G2/M phase arrest. In addition, PAT induced endoplasmic reticulum stress (ERS) and induced apoptosis, as evidenced by Ca2+ increase, ER enlargement and swelling, and upregulation of ERS-related genes and proteins expression, and increased expression of three apoptotic pathway proteins under ERS, including CHOP, JNK, and caspase-12. Meanwhile, N-acetylcysteine (NAC, a ROS scavenger) reversed the negative effects of PAT treatment on cells. These results clarify that excessive ROS production by PAT-treated AC16 cells not only causes DNA damage, leading to cell cycle arrest, but also causes ERS, which triggers apoptotic pathways to cause apoptosis.

Effect and mechanism of Fisetin on myocardial damage induced by Patulin.

OBJECTIVES OF THE STUDY: The aim of this study is to investigate whether fisetin can effectively reduce the myocardial damage induced by patulin. This study also aims to reveal the mechanism and target of fisetin in inhibiting myocardial damage. MATERIALS AND METHODS: Network pharmacology was used to screen the targets of fisetin on myocardial damage and the regulatory network of active ingredients-drug targets was constructed. GO and KEGG enrichment analyses were performed to screen out the key pathways and targets of fisetin on myocardial damage. Patulin induced apoptosis in H9c2 cardiomyocytes to verify the key targets. The mechanism of fisetin in inhibiting myocardial damage was determined. RESULTS: FIS can reduce the apoptosis of cardiomyocytes by protecting cardiomyocytes from PAT injury. According to the results of network pharmacology analysis, combined with enzyme activity detection and WB experiment, it was found that the mechanism of FIS to reduce myocardial damage may be related to the P53 signaling pathway, Caspase3/8/9 and Bax/Bcl-2. CONCLUSION: FIS plays a protective role in PAT-induced myocardial damage. On the one hand, FIS inhibits the protein overexpression of P53, Caspase-9 and Bax. On the other hand, FIS enhances the protein expression of Bcl-2.