Abstract:
Objective: To investigate the mechanisms underlying the hypoglycemic and hypolipidemic effects of Jin-Ju tea (JJT), a medicinal and edible formula composed of
Abelmoschus manihot,
Helianthus tuberosus, and
Taraxacum mongolicum, in rats with type 2 diabetes mellitus (T2DM). Methods: A T2DM rat model was established using a high-fat diet combined with streptozotocin injection. Successfully modeled rats were divided into the diabetic model (DM) group, metformin (MET) group, JJT low-dose (JJTL, 200 mg/kg), JJT medium-dose (JJTM, 400 mg/kg), and JJT high-dose (JJTH, 800 mg/kg) groups, with a normal control (CON) group also included. After 8 weeks of continuous intragastric administration, an oral glucose tolerance test was performed. Fasting blood glucose, glycated serum protein, fasting insulin, four lipid profile indicators, liver function, and pro-inflammatory cytokine levels were measured. The composition of the gut microbiota was analyzed via 16S rRNA sequencing, and correlations between microbial changes and metabolic indicators were explored. Results: Compared with the DM group, the JJTM group showed significant reductions in fasting blood glucose, glycated serum protein, and oral glucose tolerance test - area under the curve (
P<0.05), along with a marked increase in fasting insulin levels (
P<0.01). Serum levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol were significantly decreased (
P<0.001), while high-density lipoprotein cholesterol were significantly increased (
P<0.01). Levels of the pro-inflammatory cytokines interleukin-6, interleukin-1
β, and tumor necrosis factor
-α were significantly reduced (
P<0.001). Aspartate aminotransferase and alanine aminotransferase activities decreased significantly by 47.64% and 35.76%, respectively (
P<0.001). JJT increased the diversity of the gut microbiota and modulated its structure in T2DM rats, specifically upregulating the relative abundances of
Lactobacillus,
Bacillus, unclassified_Muribaculaceae, and Prevotellaceae_UCG_001, while downregulating
Dubosiella, unclassified_Lachnospiraceae, and Lachnospiraceae_NK4A136_group. Correlation analysis indicated that Prevotellaceae_UCG_001,
Bifidobacterium, and
Dubosiella were closely associated with glycemic and lipid metabolic indicators. Conclusion: JJT effectively ameliorates T2DM, with the JJTM group exhibiting the most pronounced effects. The underlying mechanism may be related to the alleviation of inflammatory responses and modulation of the gut microbiota structure.