中华猕猴桃的防癌作用 (四)浓缩猕猴桃汁阻断N-亚硝酰胺的体内合成——大鼠胚胎毒性实验

在妊娠第7、8、9天经口给孕鼠不同剂量的前体物亚硝酸钠(分别为0.125、0.25、0.50、1.00和2.00mmol/kgBW)和乙基脲(剂量是亚硝酸钠的二倍),同时给浓缩猕猴桃汁或4％淀粉液。不给猕猴桃汁的各组随前体物剂量增大,活胎率下降,吸收胎率逐渐增加,分别为5.21％,43.66％,71.70％,85.80％和100％。最高剂量组胚胎全部死亡,并有半数孕鼠中毒死亡。单给高剂量亚硝酸钠或乙基脲则不引起胚胎或孕鼠死亡。表明亚硝酸钠和乙基脲在大鼠体内合成N-亚硝基乙基脲,并通过胎盘引起胚胎死亡。前体物与胚胎毒性之间有明显的剂量反应关系。同时给孕鼠浓缩猕猴桃汁的各组在亚硝酸钠0.125-0.50mmol/kgBW者胚胎存活率无明显减少,仅最高剂量组活胎率明显减少,吸收胎率达58.6％,但无孕鼠中毒死亡。实验结果表明浓缩猕猴桃汁能明显阻断大鼠体内N-亚硝基乙基脲合成,预防所引起的胚胎毒性。

THE EFFECTS OF ACTINIDIA CHINENSIS PLANCH ON THE PREVENTION OF CANCER IV. The Blocking Effects of Concentrated Juice on theN-nitroso Ethyl Urea (NEU) in Vivo——RatEmbryotoxicity Test

In order to observe the effect of Actinidia chinensis Planch fruit juice on blocking the formation of N-nitrosamide in vivo, 99 pregnant Wistar rats were divided into five groups. The rats of each group were orally given ni-trosamide precursor ethylurea (0.25, 0.50, 1.00, 2.00 4.00 mmol/kg) and NaNO2 (0.125, 0.25, 0.50, 1.00, 2.00 mmol/kg) respectively once a day for three days, on the 7th, 8th and 9th day of pregnancy. Half of the rats in. each group were administrated two precursors and a 4% starch solution, while the other half were administrated two precursors and the tested fruit juice.In the groups without the juice, NEU was formed in vivo, which led to a high mortality of embryos. The embryolethality was 5.21%, 43.66%, 71.7%, 85.8% and 100% respectively, and 4 pregnant rats died in the highest dosage group. However, the rats who received both the two precursors and the tested fruit juice, the living embryos and embryolethality were similar to the control groups except the highest dosage group. The none treatment group and groups only given one of the precursors were done as control groups. The results suggested that the concentrated juice could block the formation of NEU in vivo and prevent the embryotoxicity of NEU.