A repeated dose 28-day oral toxicity study of extract from cultured Lentinula edodes mycelia in Wistar rats.

To evaluate the toxicological safety of extract from cultured Lentinula edodes mycelia (L.E.M.), repeated doses (2,000 mg/kg/day) were administered to male and female Wistar rats for 28 days. No mortality or abnormality in the general status or appearance was observed in rats administered L.E.M extract. Body weight and food consumption decreased slightly, particularly in the case of male rats, although the degree of decrease was not as prominent toward the end of administration. Examination of hematology, serum biochemistry, absolute and relative organ weights, autopsy and histopathology revealed only a few statistically significant differences between the treatment and control groups; these differences suggested no clinically significant changes related to toxicity. Consequently, the no observed adverse effect level (NOAEL) of L.E.M. extract was considered to be more than 2,000 mg/kg/day under the conditions of the present study.