a Effects of AGs on the mitochondrial structure and shape of the kidney. Scale bar: 1 µm; b reactive oxygen species (ROS) levels, mitochondrial superoxide levels, mitochondrial membrane potential (MMP), mitochondrial DNA (mtDNA) copy number, and ATP levels were measured in NRK-52E cells; c ROS levels, mitochondrial superoxide levels, MMP, mtDNA copy number, and ATP levels were measured in HEI-OC1 cells. The GM, ETM, and AMK-L groups were treated at a concentration of 3 mM for 48 h; the AMK-H group was treated at a concentration of 9 mM for 48 h. The results are presented as the means ± SEM (n = 6). *P < 0.05, **P < 0.01, ***P < 0.001 vs. control group. #P < 0.05, ##P < 0.01, ###P < 0.001 vs. GM-treated group.