Possible Interaction: Tamoxifen and Vitamin C

“Various antioxidants (vitamin E, vitamin C , β-carotene, catalase, and superoxide dismutase) inhibited all these cellular effects of Tam.”

“Pre‐treatment with vitamin C caused a dose‐dependent attenuation of cytotoxicity, as measured by acridine‐orange/propidium iodide (AO/PI) and Annexin V assay after treatment with TAM.”

“ Vitamin C dose‐dependently protected cancer cells against lipid peroxidation caused by TAM treatment.”

“Conclusion: The results compared vitamin C-treated breast cancer patients with normal individuals and showed that co-administration of vitamin C is more beneficial in breast cancer patients treated with tamoxifen.”

“The concurrent exposure of the explants to 100 micro M tamoxifen with 1mM ascorbic acid reduced the level of alpha-hydroxytamoxifen substantially (68.9%).”

“17beta-estradiol, synthetic estrogen diethylstilbestrol, and partial agonist tamoxifen were found to inhibit ascorbic acid accumulation in a dose-dependent fashion.”

“The administration of riboflavin (45 mg/kg … (100 mg/kg bw/day) and ascorbic acid (200 mg/…) along with tamoxifen (45 mg/kg bw/day) caused a significant decrease in the activity of glycolytic enzymes … increase in the activities of gluconeogenic enzymes to near normal levels in experimental animals.”

“E(2) significantly elevated both AA and LHRH release and the minimal effective dose was 10(-7) M. A combination of E(2) (10(-7) M) and tamoxifen (10(-6) M) totally blocked E(2)-induced AA and LHRH release.”

“Additionally, ascorbic acid and glutathione, inhibitors of covalent binding of tamoxifen , produced an elevation of methylated catechol.”