Drugs that inhibit which complex in the Electron Transport Chain can lead to increased oxidation stress?

Inhibiting Complex 3 of the Electron Transport Chain (ETC) can lead to increased oxidative stress due to the accumulation of partially reduced intermediates and increased production of reactive oxygen species (ROS). Complex 3, also known as cytochrome b-c1 complex, plays a crucial role in transferring electrons from coenzyme Q (ubiquinone) to cytochrome c. When this complex is inhibited, the transfer of electrons is disrupted, causing a backlog of electrons before this point in the chain.

As electrons become trapped at the level of Complex 3, they can interact with oxygen, resulting in the formation of superoxide radicals—one of the primary ROS. These radicals can cause damage to cellular components, such as lipids, proteins, and DNA, which contributes to oxidative stress. Therefore, the inhibition of Complex 3 not only affects ATP production but also increases oxidative damage, impacting cellular health and function.

In contrast, inhibition of Complex 1, Complex 2, or Complex 4 primarily affects ATP synthesis and may not lead to the same extent of oxidative stress as Complex 3, since they involve different paths of electron transfer or do not favor the formation of reactive intermediates to the same degree. Complexes