Comprehensive analysis of transcriptomics and metabolomics to illustrate the underlying mechanism of helenalin against hepatic fibrosis

This study aimed to investigate the protective mechanisms of helenalin on hepatic fibrosis. In brief, rats were intragastrically administrated with 50% CCl4 for 9 weeks to induce liver fibrosis, followed by treatment with various agents for 6 weeks. The effects of helenalin on hepatic injury were assessed by pathological examinations. The potential targets were predicted by the "Drug-Disease" bioinformatic analysis and then verified by multiple experiments. Moreover, the underlying mechanism was investigated by transcriptomics and metabolomics as a whole. The results showed that helenalin significantly alleviated hepatocyte necrosis and hepatic injury, as proved by the pathological examinations. Also, helenalin markedly attenuated hepatocyte apoptosis by regulating the expression of caspase-3 and Bcl-2 families. Besides, helenalin could significantly reduce collagen accumulation, as evidenced by the decreased contents of collagen, hyaluronic acid and laminin. Moreover, helenalin significantly down-regulated the phosphorylation of PI3K, Akt, FAK, mTOR and P70S6K, and PTEN protein expression, suggesting that helenalin inhibited the PI3K/Akt signaling cascade. Meanwhile, helenalin inhibited the NF-κB signaling pathway by reducing the phosphorylation of IκBα, NF-κB p65 and IKKα/β, alleviating inflammation response. Interestingly, the analysis of transcriptomics and metabolomics indicated that helenalin inhibited the glycerophospholipid metabolism pathway by down-regulating the target genes (CHKA, ETNPPL, LYPLA1, PCYT2, PLD4 and PNPLA6), ultimately ameliorating hepatocyte damage. In conclusion, helenalin ameliorates hepatic fibrosis by regulating the PI3K/Akt and NF-κB signaling pathways and the glycerophospholipid metabolism pathway.