Cordyceps militaris (C. militaris) is a parasitic fungus that grows on the larvae of Lepidoptera. It is a well-known fungus with immunomodulatory activity. Despite the fact that there was no adverse effect observed in previous animal safety studies of C. militaris mycelium, including acute oral toxicity assay, 3 different test systems of genotoxicity test and teratogenicity study, subchronic toxicity of C. militaris mycelium has not yet been investigated. Therefore, the study was conducted to further clarify the edible safety of C. militaris mycelium for long term use. Eighty Sprague-Dawley (SD) rats were divided into four groups (10 males and 10 females in each group). Rats were orally administrated with reverse osmosis water (control) or 2,000, 3,000 and 4,000 mg/kg BW/day freeze dried C. militaris mycelium powder for 90 consecutive days. Clinical observation of the rats was carried out daily. The body weight and feed intake of the rats was recorded weekly. At the end of the study, all rats were sacrificed and the blood and organs were collected for hematology, clinical biochemistry and histopathological examination. All animals survived until the end of the study. During the study period, no abnormality occurred in clinical signs, body weight, feed intake, ophthalmological examination and urinalysis. There were no significant differences upon gross necropsy between the treatment and control group. Hematology, clinical biochemistry parameters and histopathological examination showed no treatment-related change. According to the results, the no-observed-adverse-effect level (NOAEL) of C. militaris mycelium is determined to be greater than 4,000 mg/kg BW/day for male and female SD rats. The results of this study provide support for the use of C. militaris fermentation product as a safe agent in functional food.
Jhou, B.-Y., Fang, W.-C., Chen, Y.-L., & Chen, C.-C. (2018). A 90-Day Subchronic Toxicity Study of Submerged Mycelial Culture of Cordyceps militaris in Rats. Toxicology Research. doi:10.1039/c8tx00075a