Uveal melanoma cells were inoculated into the choroid of nude mice and treated with or without
intraocular injection of
zeaxanthin. After 21 days, mice were sacrificed and the eyes enucleated. Histopathological analysis was performed in
hematoxylin and
eosin stained frozen sections.
Melanoma developed rapidly in the control group (without treatment of
zeaxanthin).
Tumor-bearing eye mass and
tumor mass in the control group were significantly greater than those in
zeaxanthin treated group.
Melanoma in the controlled eyes occupied a large part of the eye, was epithelioid in morphology, and was with numerous mitotic figures. Scleral perforation and extraocular extension were observed in half of the eyes.
Melanomas in
zeaxanthin treated eyes were significantly smaller with many
necrosis and apoptosis areas and no extraocular extension could be found. Quantitative image analysis revealed that the
tumor size was reduced by 56% in eyes treated with low dosages of
zeaxanthin and 92% in eyes treatment with high dosages of
zeaxanthin, as compared to the controls. This study demonstrated that
zeaxanthin significantly inhibits the growth and invasion of human
uveal melanoma in nude mice, suggesting that
zeaxanthin may be a promising agent to be explored for the prevention and treatment of
uveal melanoma.