Liraglutide, not dapagliflozin, normalized renal inflammation and fibrosis in STZ-diabetic rats
Background
Diabetic kidney disease (DKD) is a severe complication of diabetes, characterized by progressive inflammation and fibrosis, often leading to end-stage renal disease. Current standard-of-care treatments primarily focus on glycemic and blood pressure control, but often fall short in directly addressing the underlying inflammatory and fibrotic pathways. GLP-1 receptor agonists like liraglutide and SGLT2 inhibitors like dapagliflozin have shown renoprotective effects, yet their comparative efficacy and combined impact on specific markers of renal inflammation and fibrosis remain underexplored, particularly in direct preclinical models.
Study Design
Adult Wistar rats were divided into five groups (15-17 rats/group): control, untreated diabetes (DM), dapagliflozin-treated diabetes (1 mg/kg orally), liraglutide-treated diabetes (0.4 mg/kg subcutaneously), and a combined treatment group. Diabetes was induced via a single intraperitoneal STZ (50 mg/kg) injection. Treatments were administered for 8 weeks. Researchers assessed renal inflammation (C-reactive Protein (CRP), TNF-α, IL-6), oxidative stress (TBARS, GPx, nitric oxide), and fibrosis (TGF-β, collagen type IV) via biochemical assays.
Results
Diabetes significantly increased kidney-to-body weight ratio, which remained unchanged by any treatment. Diabetic rats exhibited elevated renal inflammatory markers, including C-reactive Protein, tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6), alongside increased oxidative stress marker thiobarbituric acid reactive substances (TBARS). Liraglutide treatment normalized levels of CRP and TNF-α, though the addition of dapagliflozin provided no further improvement. None of the treatments altered renal IL-6, TBARS, or glutathione peroxidase (GPx) levels, but all treatment groups showed reduced nitric oxide. Diabetes also led to increased renal fibrosis.
Liraglutide, but not dapagliflozin, normalized renal fibrosis, tumor growth factor-β (
TGF-β), and collagen type IV levels in the diabetic rat kidneys, demonstrating superior anti-fibrotic effects.
Key Findings
- Liraglutide normalized renal C-reactive Protein and TNF-α levels in diabetic rats.
- Liraglutide, but not dapagliflozin, normalized renal fibrosis markers TGF-β and collagen type IV.
- Combined liraglutide and dapagliflozin offered no additional benefit over liraglutide alone for CRP or TNF-α.
- All treatments reduced renal nitric oxide levels.
- No treatment altered renal IL-6, TBARS, or GPx levels.
Why It Matters
This study highlights that liraglutide offers distinct and superior renoprotective benefits over dapagliflozin in mitigating inflammation and fibrosis in diabetic kidney disease, even when dapagliflozin is co-administered. For clinicians and biohackers, this suggests that GLP-1 agonists like liraglutide may be a more potent therapeutic option for directly targeting the structural damage of DKD, beyond their glucose-lowering effects. The findings reinforce the potential for liraglutide as a standalone or primary agent in protocols aimed at preventing or slowing diabetic kidney injury, particularly where inflammation and fibrosis are key concerns. This preclinical data supports further investigation into liraglutide's direct anti-inflammatory and anti-fibrotic mechanisms in human DKD progression.
liraglutide
dapagliflozin
diabetic kidney disease
inflammation
fibrosis
glp-1 agonist