Figure 7. Effect of jineol on the lysosomal and proteosomal degradations of tyrosinase in melan-a cells.

(A) Cells (3 × 10⁵ cells/ml) were pretreated with 25 μg/ml of cycloheximide (a protein synthesis inhibitor) for 1 h. Separately, cells were pretreated with 10 μM MG-132 (a proteasomal inhibitor) or 50 μM chloroquine (lysosomal degradation inhibitor) for 1 h. These cycloheximide, MG-132, or chloroquine pretreated cells were then treated with jineol for 6 h. Whole cell lysates were subjected to western blot analysis using anti-tyrosinase antibodies. Equal protein loadings were confirmed using β-actin antibodies. (B) Melanin contents were determined in triplicate, and results are presented as means ± SDs. *P < 0.05, versus non-treated controls, Student’s t-test.