The processing mechanism of vinegar-processed Curcumae Rhizome enhances anti hepatic fibrotic effects through regulation of PI3K/Akt/mTOR signaling pathway.

BACKGROUND

Hepatic fibrosis, a chronic pathological condition resulting from various forms of persistent liver injury, in the later stage, it can evolve into cirrhosis and even liver cancer. Curcumae Rhizoma (CR), traditionally recognized for its properties in line qi break blood, eliminate accumulation and relieve pain. According to traditional Chinese medicine (TCM) principles, vinegar-processing enhances CR's ability to enter the liver meridian and act on the blood level, potentially augmenting its therapeutic effects on hepatic diseases. Therefore, vinegar-processed Curcumae Rhizoma (VCR) is frequently employed in treating liver fibrosis and related hepatic conditions. However, the underlying mechanisms of vinegar processing in enhancing its therapeutic efficacy remain unclear.

METHODS

The anti-liver fibrosis effects of CR and VCR were verified at individual and cellular levels. Subsequently, HPLC-Q-TOFMS and pharmacokinetic analysis were utilized to elucidate the potential bioactive substances underlying the enhanced anti-fibrotic efficacy of VCR. Building upon these findings, network pharmacology and metabolomics were integrated to screen for key effect components and regulatory pathways. Finally, the mechanisms of action were further analyzed and validated at the tissue and cellular levels through Western blotting (WB) and molecular docking studies.

RESULTS

Both CR and VCR exhibited therapeutic effects against hepatic fibrosis, with VCR demonstrating enhanced efficacy after vinegar processing. 6 sesquiterpenes including furanodiene and curdione, showed significant alterations in plasma exposure and hepatic distribution post-processing. VCR significantly improved pathological liver conditions, lipid accumulation, and fibrosis severity. Additionally, VCR markedly reduced the expression of α-SMA in the liver and attenuated the elevations in liver function markers such as ALT and AST. Combined network pharmacology, metabolomics, and hepatic tissue WB analysis revealed that the reduced phosphorylation of the PI3K/Akt/mTOR pathway is a critical mechanism in VCR's anti-fibrotic effects. Experiments on LX-2 cells demonstrated that four sesquiterpenes, including furanodiene and curdione, effectively inhibited the proliferation of activated hepatic stellate cells (HSCs). Furanodiene, in particular, promoted apoptosis in activated HSCs by reducing phosphorylation levels of the PI3K/Akt/mTOR pathway proteins, increasing BAX expression, and activating downstream caspase-3 to achieve the effect of anti-liver fibrosis.

CONCLUSION

Vinegar-processing significantly increases the plasma exposure and hepatic distribution of components such as furanodiene in VCR, enhancing anti-fibrotic efficacy by downregulating the phosphorylation levels of the PI3K/Akt/mTOR pathway and promoting HSC apoptosis. This study provides a comprehensive explanation of the vinegar-processing mechanism and its role in enhancing the anti-fibrotic effects of VCR, offering insights for its clinical application in liver fibrosis treatment and reference for the mechanistic study of other vinegar-processed herbal medicines.