Objective:To observe the effects of metformin on expressions of nuclear factor-κB and intercellular adhesion molecule-1 in cultured rat glomerular mesangial cells(MCs) and explore its reno-protective mechanisms. Methods:MCs were cultured in the medium with normal glucose(group NG), high glucose(group HG),and different concentrations of metformin (group M1, 0.5 mmol/L;group M2, 1.0 mmol/L;group M3, 2.0 mmol/L). After 48h exposure, MCs were collected for mRNA and protein expression of NF-κB, ICAM-1. The expression of NF-κB and ICAM-1 mRNA was analyzed by real time polymerase chain reaction. The expression of NF-κBp65 and ICAM-1 protein was visualized by western blotting . Results:①MCs expressed NF-κB and ICAM-1. ②After stimulated by high glucose, the levels of intracelluar NF-κB, ICAM-1 mRNA and protein expression were significantly increased compared with group NG(P < 0.05). ③Compared with group HG, the expression of intracellular NF-κB, ICAM-1 mRNA was significantly decreased in group M3(P < 0.05). ④Compared with group HG, the expression of intracellular NF-κBp65 and ICAM-1 protein was significantly decreased in group M1, M2 and M3 in a dose-dependent manner(P < 0.01). Conlusion:Metformin can suppress the expression of NF-κB and ICAM-1 in glomerular mesangial cells in a concentration-dependent mode, which may partly contribute to its reno-protection.