中华猕猴桃汁阻断胃癌高发区人群的内源性N-亚硝基化合物合成

THE INHIBITORY EFFECT OF ACTINIDIA CHINENSIS PLANCH ON THE ENDOGENOUS FORMATION OF N-NITROSO COMPOUNDS IN SUBJECTS FROM A HIGH- RISK AREA FOR GASTRIC CANCER

本文以空腹胃液中挥发性亚硝胺(VNA)和24小时尿N-亚硝基脯氨酸(NPRO)排出量为指标,观察中华猕猴桃汁(简称桃汁)阻断胃癌高发区人群内源性N-亚硝基化合物(NOC)合成的阻断作用。受试者服用30ml桃汁后,空腹胃液中VNA总量由平均2.08±1.06μg/L显著下降至0.42±0.43μg/L(P<0.01),阻断率为79.8％。在NPRO试验中,受试验者摄入300mg脯氨酸后,尿NPRO排出量由本底的3.3±1.2μg/d显著升高至9.4±4.7μg/d(P<0.001)。与脯氨酸同时服用30ml桃汁后,NPRO排出量显著降低至本底水平(2.9±1.9μg/d,P<0.001)。上述阻断作用在胃粘膜病变程度不同的三组人群间未见显著性差别(P>0.1)。本研究证实,中华猕猴桃汁能有效地阻断胃癌高危人群内源性NOC合成。

The inhibitory effect of Actinidia chinensis Planch(ACP) juice on the endogenous formation of N-nitroso compounds (NOC) in the subjects from a high-risk area for gastric cancer were observed. Total concentration of volatile N-nitrosamines(VNA)in fasting gastric juice and 24-h urinary excretion of N-nitrosoproline (NPRO) were used as indices of endogenous exposure. After iagestion of 30 ml ACP juice the average total VNA concentration was significantly decreased from 2.08±1.06μg/L to 0.42±0.43μg/L (p<0.01), with an inhibitory rate 79.8%. In the NPRO test, urinary NPRO excretion was significantly increased from background level 3.3±1.2μg/d to 9.4±4.7μg/d (p<0.001) following intake of 300mg L-proline. While in the subjects intaking L-proline plus 30ml ACP juice, the elevated NPRO formation was completely blocked to the background level (2.9±1.9μg/d). There was no difference between the inhibtory effects of ACP juice in 3 groups of the subjects with various intragastric lesions. The study demonstrates that ACP juice has a strong potential of inhibitory effect on endogenous formation of NOC in the high-risk subjects for gastric cancer.