Fig. 7.

Schematic mechanism on gentamicin-induced cytotoxicity. Gentamicin may enhance the formation of reactive oxygen species (ROS), which induce the opening of the mitochondrial permeability transition (MPT) pore. The MPT pore is involved in the intrinsic apoptotic pathway, and pore is opened resulting in a swelling of mitochondria and destruction of the outer mitochondrial membrane. The presence of ROS and resulting apoptosis can lead to increased intracellular calcium concentrations. Metformin significantly reduced a gentamicin-induced increase in ROS, inhibited gentamicin-induced apoptosis, and stabilized the intracellular calcium concentration.