Experimental Study On Toxicological Safety Evaluation Of Comtent In Dendrobium Nobile Lindl Capsule

Object:To evaluate the toxicological safety of content in Dendrobium nobile lindl capsule for the purpose of providing scientific evidences for further market development and application.Methods:1. Acute toxicity test:Mice were orally treated with Dendrobium nobile lindl at 10.00g/kg·bw (maximum tolerated dose, MTD) as a single dose, and the death and changes in behaviors of the treated animals were observed for 14 days.2. Ames test: Ames test was conducted with Salmonella typhimurium tester strains TA97, TA98, TA100 and TA102. The rat liver microsomal enzymes (S-9) induced by polychlorinated biphenyls (PCB) were used in vitro metabolic activation system. We counted the number of revertant colonies in these strains at the levels of different exposure (5000μg/plate, 1000μg/plate,200μg/plate,40μg/plate and 8μg/plate) respectively. These tests were repeated once under the same experimental conditions.3. Bone marrow micronucleus test:Mice were orally administered with Dendrobium nobile lindl by 24-hour intervals method at the doses of 3.33g/kg·bw,1.67g/kg·bw and 0.83g/kg·bw respectively. We calculated the micronucleus rate of 1000 polychromatic erythrocytes of every animal and the ratio of polychromatic erythrocytes to mature red blood cell (PCE /NCE).4. Sperm abnormality test:Mice were orally treated once a day with Dendrobium nobile lindl at the doses of 3.33g/kg·bw,1.67g/kg·bw and 0.83g/kg·bw respectively for 5 days. All the animals were sacrificed in the thirtieth day after the last administration to calculate sperm malformation rates.5.30-day feeding test: Rats were administrated Dendrobium nobile lindl at three doses of 0.6g/kg·bw,0.9g/kg·bw and 1.2g/kg·bw respectively for 30 days. At the end of the test, all the animals were sacrificed and we observed alternations of body weight, food utilization, routine blood and blood biochemical parameters, organ weight and organ coeffient of all rats. The changes on gross anatomy and histoopathological examinations were also observed.Results:1. The maximum tolerated dose of mice treated with Dendrobium nobile lindl was larger than 10.00 g/kg·bw (equivalent to the dose that is 833 times human recommended dose). According to the acute toxicity classification standard in "Technical specifications for Inspection and Evaluation of Health Food (2003 edition)", Dendrobium nobile lindl was practically non-toxic.2. The results of Ames test, mouse bone marrow micronucleus test and sperm abnormality test were negative.3. During 30-day feeding test, no significant alternation was found in body weight, food utilization, routine blood and blood biochemical parameters, organ weight and organ coeffient in rats treated with Dendrobium nobile lindl(P>0.05) compared to the control group. Gross anatomy and histopathology examination also revealed no obvious abnormality.Conclusions:Dendrobium nobile lindl has no significant acute and sub-acute toxicity and mutagenic effect and is safe as a health food.