Evaluation of corneal damage caused by the anticancer drug S-1 in human corneal epithelial cells

The combination drug S-1, which contains tegafur, gimeracil, and oteracil potassium, is a fluoropyrimidine-based oral antineoplastic agent in which the principal drug tegafur is a prodrug of fluorouracil （ 5-FU ） . In recent years, many studies have reported eye problems, especially corneal damage, as an adverse effect of S-1 treatment. In this study, we investigated the cytotoxic effects of each of the constituents of S-1 on corneal epithelial cells by measuring viable cell counts and lactate dehydrogenase （ LDH ） release. study for 5-FU and the constituents of S-1 （ i.e., tegafur, gimeracil, and oteracil ） using a human cell line. We used immortalized human epithelial （ HCE-T ） cells to estimate viable cell counts （ expressed as a percentage of the control cells ） and the activity of LDH in a culture medium （ expressed as a percentage of the total LDH activity ） . Decreases in viable cell counts were noted with 5-FU and tegafur, but a significant elevation in LDH activity was noted only with tegafur. corneal epithelium by 5-FU is involved in the corneal injury mechanism of S-1.