Jiaogulan (Gynostemma pentaphyllum) is a traditional herb with potential antidiabetic properties. This study investigated the underlying mechanisms of these properties by analysing plasma protein profiles in type 2 diabetes patients. A total of 42 participants were divided into three groups, each comprising 14 individuals: healthy controls (N), untreated type 2 diabetes patients (DM), and Jiaogulan-treated type 2 diabetes patients (DMJ). Proteomic analysis, integrated with bioinformatics and molecular docking, was conducted. This analysis identified 24 unique proteins in the healthy control group, 16 in the untreated diabetic group, and 19 in the Jiaogulan-treated group. Notably, the Jiaogulan-treated group exhibited statistically significant upregulation of proteins involved in insulin signalling, including CCDC88A (Girdin), with a p value of <
0.05. This protein is a critical regulator of insulin sensitivity that interacts with the Akt and PI3K pathways. Furthermore, molecular docking analysis identified gypenoside, a bioactive compound from Jiaogulan, as a potential inhibitor of protein phosphatase 2A (PP2A), an important regulator of insulin signalling. PP2A inhibition preserves the phosphorylation of critical signalling molecules, such as Akt, facilitating glucose uptake and metabolism. These findings suggest that Jiaogulan may increase insulin sensitivity by modulating key proteins in the insulin signalling pathway, such as Girdin, and inhibiting PP2A activity. This inhibition might help maintain the phosphorylation of critical signalling molecules such as Akt, thereby promoting glucose uptake and metabolism. Ultimately, this research suggests that Jiaogulan has significant potential therapeutic benefits for individuals with type 2 diabetes.