49I-15 |
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H. Y. KEUNG, Department of Biology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, 852, China and P. C. K. Cheung, Food and Nutritional Sciences Programme, The Chinese University of Hong Kong, Shatin, New Territories, HongKong, China. Pleurotus tuber-regium (Ptr) is a tropical sclerotial mushroom which has been gaining interest recently as a functional food in terms of its nutritional, medicinal and economic values. Sclerotia of Ptr, which are dry mass of fungal hypha, have been used as a traditional medicine in Africa for constipation, headache, and dental problems. Recent studies have also revealed that the bioactive components, especially polysaccharides from Ptr sclerotia possess antitumor activity. However, safety evaluation on their toxicity is rare. This research evaluated the possible toxicity resulted from the consumption of the mushroom sclerotia by animal model. Acute toxicity of Ptr sclerotia was evaluated by single dose oral feeding of 7-weeks female S.D. rats with a sclerotium-based diet. Death, reduced body weight and clinical symptoms in the animals were monitored for a 4-day period. Hepatotoxicity in the animals was biochemically determined by measuring their serum glutamate pyruvate transaminase (GPT) and serum glutamate oxaloacetate transaminase (GOT) levels. Light microscopy was used to check signs of necrosis or steatosis in the rat,s liver caused by adverse biochemical changes. Finally, genotoxicity of the mushroom sclerotia would also be studied using comet assay to find out any DNA breakages induced by genotoxic substances. No toxic symptoms were shown in the rats during the feeding period at a level of 53 g sclerotium/kg body weight over a period of 4 days. Blood serum GPT and GOT levels in the sclerotium-diet group (19.82 IU/L and 60.09 IU/L, respectively) were not significantly different (p > 0.05) from the control group fed with normal rodent chows (22.04 IU/L and 88.46 IU/L, respectively) (Student,s t-test, P>0.05). This research provides some basic information on the toxicity of Ptr sclerotia which are important for the development of mushroom scleortia and their products as a safe functional food.
Session 49I, Toxicology & Safety Evaluation: General
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