Baicalin induces ferroptosis in HepG2 cells by inhibiting ROS-mediated PI3K/Akt/FoxO3a signaling pathway

Abstract

This study aims to investigate whether baicalin induces ferroptosis in HepG2 cells and decipher the underlying mechanisms based on network pharmacology and cell experiments. HepG2 cells were cultured in vitro and the cell viability was detected by the cell counting kit-8(CCK-8). The transcriptome data of hepatocellular carcinoma were obtained from the Cancer Genome Atlas(TCGA), and the ferroptosis gene data from FerrDb V2. The DEG2 package was used to screen the differentially expressed genes(DEGs), and the common genes between DEGs and ferroptosis genes were selected as the target genes that mediate ferroptosis to regulate hepatocellular carcinoma progression. The functions and structures of the target genes were analyzed by Gene Ontology(GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment with the thresholds of P<0.05 and |log_2(fold change)|>0.5. DCFH-DA probe was used to detect the changes in the levels of cellular reactive oxygen species(ROS) in each group. The reduced glutathione(GSH) assay kit was used to measure the cellular GSH level, and Fe~(2+) assay kit to determine the Fe~(2+) level. Real-time quantitative PCR(RT-PCR) was employed to measure the mRNA levels of glutathione peroxidase 4(GPX4) and solute carrier family 7 member 11(SLC7A11) in each group. Western blot was employed to determine the protein levels of GPX4, SLC7A11, phosphatidylinositol 3-kinase(PI3K), p-PI3K, protein kinase B(Akt), p-Akt, forkhead box protein O3a(FoxO3a), and p-FoxO3a in each group. The results showed that treatment with 200 μmol·L~(-1) baicalin for 48 h significantly inhibited the viability of HepG2 cells. Ferroptosis in hepatocellular carcinoma could be regulated via the PI3K/Akt signaling pathway. The cell experiments showed that baicalin down-regulated the expression of SLC7A11 and GPX4, lowered the GSH level, and increased ROS accumulation and Fe~(2+) production in HepG2 cells. However, ferrostatin-1, an ferroptosis inhibitor, reduced baicalin-induced ROS accumulation, up-regulated the expression of SLC7A11 and GPX4, elevated the GSH level, and decreased PI3K, Akt, and FoxO3a phosphorylation. In summary, baicalin can induce ferroptosis in HepG2 cells by inhibiting the ROS-mediated PI3K/Akt/FoxO3a pathway.