Gan-tang-yi decoction improves hepatic insulin resistance through activation of IRS2/PI3K/Akt pathway and inhibition of AGEs/RAGE pathway in cirrhotic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Non-alcoholic fatty liver diseases (NAFLD), including nonalcoholic steatohepatitis (NASH) and cirrhosis, are strongly associated with insulin resistance and glucose intolerance. Gan-tang-yi decoction (GTYD), as a famous classical prescription effectively reduced the elevated level of blood glucose, and improved insulin resistance in cirrhotic patients. However, its specific chemical compositions and molecular mechanisms are still unclear.

AIM OF THE STUDY: The current study aimed to investigate the active ingredients of GTYD and molecular mechanisms underlying the effect of GTYD against insulin resistance of NASH and cirrhosis.

MATERIALS AND

METHODS

Active ingredients of GTYD were evaluated by UPLC-Q-TOF/MS in both positive and negative ion modes. The TCMSP database and SwissTarget Prediction database were utilized to identify the major active components and possible targets of GTYD. The diabetes-related targets were screened in the databases of GenCLiP 3, OMIM, and GeneCards. The intersection of these databases was utilized to identify possible GTYD targets for insulin resistance. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. Protein-protein interaction (PPI) network and hub target proteins were obtained from the STRING database. The hub targets were validated by RT-qPCR analysis. Furthermore, an insulin-resistant rat model of NASH and cirrhosis was created by subcutaneously injecting CCl4 combined with high fat and high sucrose diet to verify the therapeutic effects and the molecular mechanisms of GTYD in vivo.

RESULTS

A total of 91 compounds were identified from GTYD by UPLC/Q-TOF-MS/MS. After removing duplicates, there were 230 targets associated with both disease and medicines. Targets of GTYD involve many biological processes, such as the positive regulation of cellular metabolic and cellular lipid metabolic processes. KEGG enrichment showed that PI3K/Akt and AGE/RAGE pathways played a prominent role in the treatment. RT-qPCR from the GTYD-treated rats revealed that TNF-α, IL-6, VEGFA, STAT3, IL-1B, and MAPK3 mRNA levels in the insulin resistance of NASH and cirrhosis rats were down-regulated. Up-regulated IRS2/PI3K/Akt and down-regulated AGE/RAGE and MAPK/NF-κB signal pathways were closely related to the therapeutic effect of GTYD against insulin resistance of NASH and cirrhosis rats by biology methods.

CONCLUSIONS

GTYD functions as a hepato-protective formula in the insulin resistance of NASH and cirrhosis and exerts its effects via IRS2/PI3K/Akt and AGEs/RAGE signaling pathways.