Reduced levels of rat lens antioxidant vitamins upon in vitro UVB irradiation

Ultraviolet (UV) radiation is one of the major risk factors of cataractogen esis. UV radiation induced damage to the eye lens is believed to be mediate d through reactive oxygen species. Antioxidant defense systems, enzymatic a nd non-enzymatic, resist this damage. In the present study, the levels of r at lens endogenous antioxidants, L-ascorbic acid, alpha -tocopherol and bet a -carotene, have been determined by HPLC upon in vitro UVB irradiation. UV B irradiation for 24 h (300 nm; 100 muW/cm(2)) of three months old rat lens suspended in RPMI medium, leads to 69-89% decrease in endogenous levels of these antioxidants. The addition of ascorbic acid (2 mM), alpha -tocophero l (2.5 muM) or beta -carotene (10 muM). separately to the medium during irr adiation significantly prevented the decrease in their endogenous levels, t hereby suggesting a protective role for these antioxidant micronutrients ag ainst photodamage to the eye lens. (C) 2001 Elsevier Science Inc. All right s reserved.