QUANTITATION OF VITAMIN-E AND A CAROTENOID PIGMENT IN CATARACTOUS HUMAN LENSES, AND THE EFFECT OF A DIETARY-SUPPLEMENT

The quantitation of tocopherols and carotenoids in lipid extracts of c ataractous human lenses was performed in parallel with those of matche d samples of plasma, which was also analysed at the same time. Alpha-t ocopherol in cataractous lenses from elderly human subjects was presen t at 4.4 mu mole/kg wet weight, much less than the mean of 33 mu moles /l in plasma from these subjects. The mean ratio of alpha- and gamma-t ocopherols was 3.5 in the lenses, and 11.3 in plasma. Lens extracts co ntained no detectable alpha- or beta-carotene, lycopene, or beta-crypt oxanthin. However all the lens extracts contained a pigment with the r etention time and spectrum of lutein and zeaxanthin. Using the molar e xtinction coefficient of lutein this was present at ca. 0.03 mu M, com pared with 0.2 mu M in plasma. Seven patients with bilateral cataracts had one of their cataractous lenses removed and analysed, and were th en given either air oral placebo, oran oral supplement of ascorbate, a lphatocopherol and beta-carotene Three months later; the second catara ctous lens, and a blood sample, were analysed. Three of the seven had received the active supplement, as confirmed by substantially raised b lood levels of alpha-tocopherol and beta-carotene, and raised aqueous humour levels of vitamin C. However lens tocopherol levels remained un changed, and no betacarotene could be detected in the lenses after (C) 1996 Hogrefe & Huber Publishers