Safety assessment of the fermented Phylloporia ribis (Lonicera japonica Thunb.) mycelia by oral acute toxicity study in mice and 90-day feeding study in rats.

Phylloporia ribis is an edible fungus in China. Its fermented mycelia have been approved by the National Health and Family Planning Commission (NHFPC) of PR China for use as a novel food material, but little information on its safety is available. The present research was the first to evaluate acute and subchronic toxicity in experimental animals of fermented Phylloporia ribis mycelia (FPM) following standard procedures. In acute toxicity study, FPM was orally administered to male and female mice twice a day at single dose of 10 g/kg bw. The Maximum Tolerated Dose (MTD) of FPM for mice of both sexes was over 10 g/kg bw. No death and abnormal behaviors occurred during 14 days study except for an increased locomotor activity in three animals. In 90-day feeding study, male and female Sprague-Dawley rats were fed diets containing 10.0%, 5.0%, 2.5%, 1.25% and 0% (control) FPM for 90 days. The treatment caused no effects on mortality, gross pathology, histology, hematology, and blood chemistry, no dose-dependent changes in food consumption, but caused effect on body weight gain compared with control group. The No Observed Adverse-Effect Level (NOAEL) of FPM was greater than 8.7 g/kg bw/day in both sexes of rats.