Trigonelline reduced diabetic nephropathy and insulin resistance in type 2 diabetic rats through peroxisome proliferator-activated receptor-γ.

Trigonelline has been reported to serve an important role in cell cycle control, oxidative and ultraviolet stress and DNA methylation. In the present study, the effects of trigonelline were examined on type-2 diabetes mellitus (T2DM)-induced renal dysfunction, and its possible mechanism was investigated. Sprague-Dawley rats were fed with high-fat diet (HFD) for 4 weeks and intraperitoneally injected with 35 mg/kg of streptozotocin for 4 weeks. As a result, trigonelline increased body weight, inhibited the kidney weight/body weight ratio and blood glucose levels, and reduced the levels of blood urea nitrogen, creatinine and albumin in type 2 diabetic rats. In addition, trigonelline also reduced inflammation, oxidative stress and kidney cell apoptosis in T2DM rats. In terms of the molecular mechanisms involved, trigonelline induced the protein expression of peroxisome proliferator-activated receptor (PPAR)-gamma and suppressed glucose transporter 4 but suppressed the protein expression of tumor necrosis factor-alpha and leptin in T2DM rats. The present results demonstrated that trigonelline reduced diabetic nephropathy and insulin resistance in T2DM rats through PPAR-gamma.