Toxicological safety evaluation of the new resource in Sect. Thea plant-Camellia yungkiangensis var. Yuanbaoshanica

【Objective】To evaluate the drinking safety of the new resource-Camellia yungkiangensis var. Yuan-baoshanica in Sect. Thea plant,so as to provide scientific basis for the efficient development and utilization of the resource.【Method】The fresh leaf fixed samples and black tea samples of the resource were used as materials,and the food toxicological safety evaluation program was taken as referenced to evaluate the toxicological safety of the resource through oral acute toxicity test,mouse bone marrow cell micronucleus test,Ames test and 30-day chronic feeding subacute toxicity test.【Result】The results showed that C. yungkiangensis var. Yuanbaoshanica had high content of tea polyphenols,soluble sugar and theobromine,but relatively low content of caffeine and free amino acids. The median lethal dose(LD₅₀) of the fresh leaf fixed sample extract of C. yungkiangensis var. Yuanbaoshanica to ICR mice was 5.123 g/kg. While the LD₅₀ of its black tea sample extract to mice was 7.573 g/kg. The addition of S₉ and no S₉ in each dose group of C. yungkiangensis var. Yuanbaoshanica(black tea sample extract) did not cause mutagenic effects on the test strain,indicating that the Ames test result was negative. And at a dose of 5.00 g/kg(equivalent to 144 times the recommended dosage of the human body),C. yungkiangensis var. Yuanbaoshanica(black tea sample extract) had no obvious toxic effect on mouse bone marrow cells,indicating that the results of the mouse bone marrow cell micronucleus test were negative. SD rats were given the tested samples(black tea sample extract) at doses of 0.87,1.74 and 3.47 g/kg for 30 days through oral gavage. During the experiment,no abnormalities had been found in the mental state,behavioral activity,water intake, feces,urine and secretions of each cavity in each dose group,and no rats died. And the weight gain,food intake,food utilization,hematology index,blood biochemical indicators,wet weight of organs,organ-body ratio,etc. of the rats in each dose group were significantly different(P<0.05) or extremely significantly different(P<0.01) from that of the negative control group, but most of the indicators had no significant dose response relationship, and the values fluctuated within the normal range. Moreover,no pathological changes with significant toxic effects on rats were found through gross anatomical observation and histopathological examination.【Conclusion】C. yungkiangensis var. Yuanbaoshanica is a typical and specific resource with high content of tea polyphenols,soluble sugar,theobromine and low content of caffeine,with high drinking safety. According to the food toxicological safety evaluation standards,it belongs to the non-toxic food, with a prospect as a substitute tea beverage plant.