Safety assessment of cultivated fruiting body of Ophiocordyceps sinensis evaluated through subacute toxicity in rats

ETHNOPHARMACOLOGICAL RELEVANCE: Ophiocordyceps sinensis (Berk.) G.H. Sung, J.M. Sung, Hywel-Jones & Spatafora is one of the most renowned traditional Chinese medicine used as tonic, renal, respiratory and reproductive health, promote longevity and overall improvement in quality of life. Natural production of O. sinensis is limited due to its extreme specificity in host range and confined geographic distribution. Therefore, cultivation of the fungus was developed to meet high demand for commercialization as nutraceutical. O. sinensis fruiting body has recently been successfully cultivated in large scale using rice based solid medium, providing wider source options for consumers and scientific researchers.

AIMS OF THE STUDY: The present study aims to establish safety profile for the consumption of cultivated fruiting body of O. sinensis (FBOS) by 28-days sub-acute toxicity study in Sprague Dawley rats.

MATERIALS AND METHODS: Rats were orally administered with cultivated FBOS at three graded doses (250, 500 and 1000mg/kg), once daily for 28 consecutive days. Control group received distilled water. General observations (gross behavioral changes and toxic symptoms) and body weight of each animal were monitored daily. Haematological, serum biochemical and histopathological analysis were carried out at the end of the experiment (Day 29).

RESULTS: No behavioral changes, toxic symptoms or death was observed in rats throughout the dosing period. Cultivated FBOS treatment up to 1000mg/kg did not cause any adverse effect on the growth of the animals. Results from haematology and serum biochemistry revealed no toxic effect following cultivated FBOS treatment at three graded doses for 28 days. In addition, no treatment related histopathological changes were noted in heart, spleen, kidney, lung and liver of the animals.

CONCLUSION: The present study revealed that oral administration of cultivated FBOS for 28 days, at dosage up to 1000mg/kg did not pose toxicological concern in rats. Therefore, the no-observed-adverse-effect level (NOAEL) dose of cultivated FBOS in 28-days subacute toxicity study is higher than 1000mg/kg.