Li et al. found that trigonelline increased peroxisome proliferator-activated receptor-gamma (PPARγ) and glucose transporter type 4 (GLUT4) protein expression while suppressing leptin and tumour necrosis factor alpha (TNF-α) protein expression in the kidneys of DKD rats, thereby reduce inflammation, oxidative stress, and kidney cell apoptosis [80]. Here, TNF is linked to diabetic kidney disease.