Assessment of mutagenicity, acute and sub-acute toxicity and human trial safety of wasabi leaf extract powder

抄録

Wasabi leaf has been reported to show human health benefits without assessment of its safety. This study aims to investigate the mutagenicity, acute and sub-acute toxicity and human trial safety of wasabi leaf extract (WLE). The Ames test was used to assess mutagenicity, while acute and sub-acute toxicity were assessed by oral administration in five-week-old Slc:ICR mice (SPF) and five-week-old Sprague-Dawley (SD) rats, respectively. Human trial safety was further determined in a clinical trial. Twelve healthy subjects, aged 20–64 years and mildly obese (BMI 23.0 to 30.0 kg/m²), were enrolled in the clinical trial, and participants ingested 200 mg WLE daily for 12 weeks. The effect of WLE on fat metabolism was evaluated by visceral fat area (VFA), subcutaneous fat area (SFA), VFA/SFA(V/S) area ratio, body weight, BMI, TG, T-Cho, HDL-C, LDL-C, waist circumference, and body fat percentage. In the Ames test, WLE did not show mutagenicity in the range of 1.2–5000 µg/plate. No acute toxicity was observed in Slc:ICR mice (SPF) administered 5000 mg/kg/day WLE, and no sub-acute toxicity was observed in Crl:CD (SD) rats administered 2500 mg/kg/day WLE. In the human clinical trial, there were no significant differences between the WLE and placebo groups for any outcome measure assessed. Thus, ingestion of 200 mg/day of WLE was demonstrated for the first time to be safe. Taken together, our data on the mutagenicity, acute and sub-acute toxicity and human trial safety of WLE provide the first standard references for wasabi leaf supplement application.