An open label pilot study to evaluate the efficacy of Spanish black radish on the induction of phase I and phase II enzymes in healthy male subjects

BACKGROUND Humans are exposed to toxins which accumulate in the body, and are detoxified primarily in the liver. Studies have shown that cruciferous vegetables (such as radishes) may be beneficial to health by aiding detoxification of toxins in the liver. METHODS This single-centre, open-label, pilot study investigated the effect of a dietary supplement containing Spanish Black Radish on hepatic function in healthy males by monitoring the profiles of plasma and urine acetaminophen metabolites and serum hormone concentrations at baseline and after 4 weeks of supplementation. A paired t-test was used to compare pre- and post-treatment of plasma and urine acetaminophen metabolite profiles, serum hormone concentrations and safety end points. RESULTS Area under the curve (AUC) from 0 to 8 hours for the acetaminophen glucuronide metabolite and unchanged acetaminophen in plasma decreased from baseline to week 4 by 9% (P = 0.004) and 40% (P = 0.010), respectively. The AUC from 0 to 8 hours for acetaminophen sulfate and mercapturate metabolites in the urine increased by 11% (P = 0.010) and 37% (P = 0.024), respectively, from baseline to week 4. The AUC from 0 to 8 hours of serum estradiol-17β decreased by 10% from baseline to week 4 (P = 0.005). All measures of clinical safety remained within acceptable laboratory ranges, however a significant reduction in plasma γ-glutamyl transferase levels was noted after 4 weeks of Spanish Black Radish treatment (P = 0.002). CONCLUSIONS These changes in metabolite and hormone levels indicate that Spanish Black Radish supplements have a positive influence on the detoxification of acetaminophen suggesting up-regulation of phase I and phase II liver enzymes. This study was sponsored by Standard Process Inc. TRIAL REGISTRATION ClinicalTrials.gov registration number NCT02137590 (Date of registration: May 12, 2014).