The sterile buffered solution of 0.2 % actinoquinol with 0.15 % hyaluronic acid, pH 7.2 was dropped on the right eye (one drop every 30 s, five drops in total)

The inhibition of EBV-EA activation was assayed using the EBV genome carrying lymphoblastoid Raji cells of human origin, which were cultivated in RPMI 1640 medium. The cells were incubated at 370 C for 48 h in 1 mL of the medium containing butyric acid (4 mM, as co-inducer), TPA (20 ng/mL, 32 pM) and a known amount of Actinoquinol in DMSO. Smears were made from cell suspension. The EBV-EA-expressing cells were stained with high titre EBV-EA-positive serum from nasopharyngeal carcinoma patients and detected by an indirect immunofluorescence technique. In each assay, 500 cells were counted, and the experiments were carried out in triplicate. The average EA induction was compared to that of a positive control experiment with butyric acid (4 mM) and TPA (32 pM).