Abstract
<title>Abstract</title> <p>The ocular surface is constantly exposed to environmental radiation. While the damaging effects of ultraviolet (UV) radiation are well established, increasing exposure to artificial blue light has raised concerns regarding photo-induced oxidative stress at the corneal level. Preventive strategies to protect corneal epithelial cells from light-induced damage are therefore of growing interest. The protective effects of a tamarind seed polysaccharide (TSP)-based ophthalmic formulation were evaluated in rabbit corneal epithelial (RCE) cells exposed to blue light (405 nm) or UV radiation (365 nm). Cell viability, intracellular and mitochondrial oxidative stress, and cell morphology were assessed using complementary biochemical and high-content imaging approaches. Blue-light exposure moderately increased oxidative stress without affecting cell viability, whereas UV irradiation induced significant cytotoxicity and ROS accumulation. TSP pre-treatment significantly reduced cytosolic and mitochondrial ROS in a dose-dependent manner under both irradiation conditions and completely prevented UV-induced loss of viability. The fluorescence image analysis confirmed increased mitochondrial superoxide after irradiation, which was significantly attenuated by TSP, with a significant irradiation–treatment interaction. High-content imaging demonstrated preservation of mitochondrial organization and epithelial morphology in TSP-treated cells while no intrinsic cytotoxic or pro-oxidant effects were observed in non-irradiated samples. TSP exerts cytoprotective effects by attenuating oxidative stress and preserving mitochondrial integrity in corneal epithelial cells exposed to blue and UV light. These results support its potential use for protecting the ocular surface against environmental and digital light exposure.</p>