Abstract
Purpose: Vitamin E delta-tocotrienol (VEDT) has demonstrated chemopreventive and antineoplastic activity in preclinical models. The aim of our study was to determine the safety and pharmacokinetics of VEDT and its metabolites after single- and multiple-dose administrations in healthy subjects. Methods: Thirty-six subjects received from 100 to 1600 mg of oral VEDT as a single dose or twice daily for 14 consecutive days. A 3 + 3 dose escalation design was utilized. Pharmacokinetic data were derived from high-performance liquid chromatography (HPLC) assays. Serial blood and urine samples were collected before and during VEDT administration, with serum and urine metabolites assessed using HPLC. Results: No drug-related adverse events were observed. Pharmacokinetic parameters for single and multiple doses were, respectively, as follows (shown as range): time to maximum concentration of 4–9.3 and 4.7–7.3 h, maximum concentration of 795.6–3742.6 and 493.3–3746 ng/mL, half-life of 1.7–5.9 and 2.3–6.9 h, and 0–12 h area under the curve of 4518.7–20,781.4 and 1987.7–22,171.2 ng h/mL. Plasma tocotrienols were significantly increased after VEDT administration, indicating oral bioavailability of VEDT in humans. Plasma and urine levels of metabolites, δ-carboxyethyl hydroxychroman, and δ-carboxymethylbutyl hydroxychroman were elevated after VEDT administration in a dose-dependent manner and were 30–60 times significantly higher than δ-tocotrienol levels. VEDT can be safely administered at doses up to 1600 mg twice daily. Plasma VEDT concentrations were comparable to those obtained in VEDT-treated mice in which tumor growth was delayed. Conclusions: Our results suggest that VEDT can be safely consumed by healthy subjects and achieve bioactive levels, supporting the investigation of VEDT for chemoprevention.
Original language | English (US) |
---|---|
Pages (from-to) | 157-165 |
Number of pages | 9 |
Journal | Cancer chemotherapy and pharmacology |
Volume | 78 |
Issue number | 1 |
DOIs | |
State | Published - Jul 1 2016 |
Keywords
- Antitumor agent
- Biomarker
- Chemoprevention
- Pancreatic cancer
- Tocochromanol
ASJC Scopus subject areas
- Oncology
- Toxicology
- Pharmacology
- Cancer Research
- Pharmacology (medical)