Hepatoprotective and neuroprotective tocopherol analogues isolated from the peels of Citrus unshiu Marcovich.

Three tocopherol analogues methoxytocopherol (1), α-tocopherol (2) and γ-tocopherol (3) were isolated from the peels of Citrus unshiu Marcovich. The protective effects of the isolated compounds against tert-butyl hydroperoxide-induced hepatotoxicity in human liver-derived HepG2 cells and glutamate-induced oxidative stress in HT22-immortalised hippocampal cells were evaluated. Compounds 1-3 were significantly protective in HepG2 cells with EC50 values of 21.22 ± 2.01, 25.21 ± 2.11 and 25.25 ± 1.21 μM, respectively, and in HT22 cells, compounds 1-3 had EC50 values of 20.62 ± 1.36, 6.44 ± 1.65 and 9.52 ± 1.54 μM, respectively.