Integrated network pharmacology and multi-omics reveals GLUD1-mediated α-KG/Glu conversion in regulating amino acid metabolism: a mechanism of Dangua Fang against type 2 diabetes mellitus.

ETHNOPHARMACOLOGICAL RELEVANCE: Amino acid metabolic disorder is one of the typical features of diabetes. The tricarboxylic acid (TCA) cycle serves as a central hub for carbon-nitrogen metabolism, with α-ketoglutarate (α-KG)/glutamate (Glu) conversion mediated by glutamate dehydrogenase 1 (GLUD1) playing a pivotal role. Dangua Fang (DGF) is a traditional Chinese medicine formula with a history spanning over two millennia, traditionally used to treat Xiaoke (diabetes). It has been shown in previous studies to effectively improve glucose-lipid metabolism and cardiovascular outcomes in patients with type 2 diabetes mellitus (T2DM), and to significantly modulate amino acid metabolism in T2DM rats.

AIM OF THE STUDY: This study aimed to identify key targets regulating amino acid metabolism in T2DM and to elucidate the mechanism by which DGF ameliorates amino acid disturbances.

MATERIALS AND

METHODS

Potential targets were screened through DGF phytochemical characterization, detection of blood-absorbed components, and integrated network pharmacology and proteomics analyses. GLUD1 inhibition experiments were conducted, with metformin used as a reference. Hepatic and urinary metabolomics were applied to evaluate the effects of DGF on amino acid metabolism in T2DM rats.

RESULTS

Network pharmacology and proteomics identified GLUD1 as a critical regulator of amino acid metabolism in T2DM and suggested that DGF may exert its effects through GLUD1 upregulation. In vivo experiments demonstrated that DGF significantly improved glucose-lipid metabolism, alleviated hepatic pathological damage, increased hepatic GLUD1 expression, and promoted TCA cycle activity and α-KG/Glu conversion. Metabolomics analyses further confirmed significant correlations between GLUD1 and amino acid metabolism, while DGF reversed disturbances induced by GLUD1 inhibition.

CONCLUSION

GLUD1-mediated α-KG/Glu conversion is a key mechanism underlying amino acid abnormalities in T2DM. DGF effectively ameliorates these disturbances in T2DM rats through upregulation of hepatic GLUD1.