Which reducing agent protects the lens against oxidative damage?

Glutathione is known as a potent reducing agent that plays a crucial role in protecting the lens from oxidative damage. It is a tripeptide composed of three amino acids: glutamine, cysteine, and glycine. In the lens, glutathione helps to maintain the redox balance by neutralizing reactive oxygen species (ROS) that can lead to cellular injury and cataract formation.

Oxidative stress can damage cellular components, including proteins, lipids, and DNA, contributing to the aging of the lens and the development of cataracts. Glutathione not only acts as a direct scavenger of free radicals but also participates in various enzymatic reactions to regenerate other antioxidants. Its concentration in the lens is critical for maintaining transparency and refractive properties, as well as overall lens health.

In contrast, other options listed, while they have roles in antioxidant defense, do not function specifically as reducing agents in the context of the lens. Ascorbic acid is another important antioxidant but more commonly associated with the aqueous humor rather than the lens. Catalase and superoxide dismutase are enzymes that also help in detoxifying reactive oxygen species, but they work in different ways than glutathione and do not serve the same