茶组植物新资源元宝山茶的毒理学安全性评价

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

【目的】评价茶组植物新资源元宝山茶(Camellia yungkiangensis var.Yuanbaoshanica)的饮用安全性,为该资源的高效开发利用提供科学依据。【方法】以元宝山茶资源的鲜叶固定样和红茶工艺样为材料,参照食品毒理学安全性评价程序,通过经口急性毒性试验、小鼠骨髓细胞微核试验、Ames试验和慢性喂养(30 d)亚急性毒性试验对其毒理学安全性进行评价。【结果】元宝山茶具有较高的茶多酚、可溶性糖及可可碱含量,但咖啡碱和游离氨基酸含量相对较低。元宝山茶鲜叶固定样提取物对ICR小鼠的半数致死剂量(LD_(50))为5.123 g/kg,其红茶工艺样提取物对小鼠的LD_(50)为7.573 g/kg;元宝山茶(红茶工艺样提取物)各剂量组在添加S_(9)与不加S_(9)时均未导致测试菌株(TA97a、TA98、TA100和TA102)出现致突变作用,即Ames试验结果呈阴性;在5.00 g/kg剂量(相当于人体推荐食用量的144倍)条件下,元宝山茶(红茶工艺样提取物)对小鼠骨髓细胞无明显毒性作用,表明小鼠骨髓细胞微核试验结果呈阴性。按0.87、1.74和3.47 g/kg的剂量经口灌胃红茶工艺样提取物给SD大鼠30 d,试验期间各剂量组大鼠的精神状态、行为活动、摄水、粪便、尿液及各腔道分泌物等均未见异常,也无大鼠死亡;其体重增重、摄食量、食物利用率、血液指标、血清生化指标、脏器湿重及脏/体比值等除个别指标与阴性对照组相比差异显著(P<0.05)或极显著(P<0.01)外,绝大部分指标均无明显的剂量—反应关系,且均在正常范围内波动;剖检观察及组织病理学检查也未发现元宝山茶对大鼠产生明显毒性意义的病理变化。【结论】元宝山茶属于典型的高茶多酚、高可溶性糖、高可可碱及低咖啡碱的特异性资源,且具有很高的饮用安全性,按食品毒理学安全性评价标准属于无毒级食品,作为代茶饮料植物具有广阔的应用前景。

【Objective】To evaluate the drinking safety of the new resource—Camellia yungkiangensis var.Yuanbaoshanica 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(LD_(50)) of the fresh leaf fixed sample extract of C.yungkiangensis var.Yuanbaoshanica to ICR mice was 5.123 g/kg.While the LD_(50) of its black tea sample extract to mice was 7.573 g/kg.The addition of S_(9) and no S_(9) 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.