Introduction: Tamoxifen is the most frequently prescribed therapy for estrogen positive breast cancer. The duration of a therapeutic course might range between five to ten years.
The purpose of this study is to examine histological reactions to Tamoxifen on retinas of adult female albino rats and the potential beneficial impact of melatonin versus lutein.
Material and Methods: Sixty adult female albino rats were randomly divided into 6 groups. Control group (I), melatonin administered group (II) rats obtained daily doses of melatonin (10 mg/kg), Lutein administered group (III) rats obtained lutein daily (50 mg/kg), Tamoxifen administered group (IV) rats obtained daily Tamoxifen (5mg/kg), Tamoxifen and melatonin treated group (V), Tamoxifen and lutein treated group (VI) rats received the aforementioned doses. At termination of the study (4 weeks), the animals were anesthetized, sacrificed, and retinal samples were collected for histological, immunohistochemical, and electron microscopic examination.
Results: Tamoxifen was found to be deleterious to retinal tissue. Both total retinal thickness and number of ganglion cells showed an extremely significant reduction. There was a significant rise in GFAP and Caspase-3 immunohistochemical reactivity. Ultrastructural alterations revealed degeneration of pigmented epithelium, distortion of photoreceptors, degeneration of outer and inner nuclear layer cells with small shrunken nuclei, intercellular gap expanding, and mitochondrial degeneration. Ganglion cells have notched, irregular nuclei and degraded mitochondria. Coadministration of Lutein exhibited significantly retinal tissue protection than melatonin.
Conclusion: Lutein has a greater protective effect on retinal tissue than melatonin against the potentially harmful effects of Tamoxifen. Patients on long term or high dose tamoxifen therapy were recommended to have regular follow up for possible retinal changes. More studies were recommended on the protective effects of lutein on patients receiving tamoxifen therapy. Various antioxidants in the market should be taken after medical consultation to take benefit of them and avoid their hazardous effects.