Abstract 3154: Human plasma, prostate and urine levels of α-, γ-, and Δ-tocopherols and their metabolites before and after supplementation with a γ-tocopherol rich vitamin E mixture

Abstract

Abstract In order to determine the blood/tissue levels of tocopherols and their metabolites, we analyzed samples from 5 prostate cancer patients who underwent prostatectomy by HPLC-ECD. These patients had a mean PSA of 6.37 (range 1.99 to 10.54) prior to surgery and a Gleason Score of 7. The plasma α-tocopherol (α-T) levels, 22.02 ± 3.85 μM (mean ± S.D., n = 10), were in the normal range. As expected, the levels of γ-T were lower and those of Δ-T were even lower. The prostate tocopherol levels were 6-14 times lower than plasma levels. Substantial amounts of carboxyethyl hydroxychromans (CEHC) and carboxymethylbutyl hydroxylchromans (CMBHC) were observed in the urine. These metabolites were also found at low levels in the plasma and prostate. In a pilot study, prostate cancer patients received no supplementation or 2 capsules of γ-TMT (a γ-T-rich dietary supplement, containing 128 mg α-T, 200 mg γ-T and 71 mg Δ-T per capsule) daily for 7 or 14 days before prostatectomy. Blood and urine samples were collected from each subject before γ-TMT supplementation and on the day of surgery. The plasma and prostate tocopherol/metabolite levels, especially those from γ-T and Δ-T, were increased in patients who received γ-TMT supplementation (but not in the patients who did not). The effect on the urine levels of tocopherol metabolites was even more evident; high levels of γ- and Δ- forms of CEHCs and CMBHCs were observed in patients who received γ-TMT supplementation. Tocopherols were not excreted in the urine even with supplementation. These results are consistent with our understanding that γ-T and Δ-T are more extensively metabolized than α-T. The rather high CEHC and CMBHC levels in the urine make them useful biomarkers for tocopherol intake and metabolism in future human studies (supported by NIH grants CA120915 and CA133021). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3154. doi:10.1158/1538-7445.AM2011-3154