[Preventive effect of green tea on MNNG-induced lung cancers and precancerous lesions in LACA mice].
Three hundred and ninety LACA mice of seven weeks old were used in 2 batches (96.4 wks and 106 wks) for studying the preventive effect of green tea on MNNG-induced lung cancers and precancerous lesions. These mice (within each batch) were randomly allocated to four groups, namely, positive control (MNNG), green tea (GT), complex (MNNG + GT), and blank control (C) group. In MNNG group, MNNG 250 micrograms) was injected intravenously every five days for seven times in each mouse; the total dosage of MNNG was 1.75mg. In GT group, according to W/W, 5% GT dust was well mixed into 95% common diet for long-term breeding. In complex group, MNNG was given as that in MNNG group and the mice were reared as those in GT group. The mice in MNNG group and in C group were all reared by common diet. The mean amount of daily intake of feed was 10g. The number of effective animals was 354. The results of experiments showed different degrees of preventive effect of green tea on MNNG-induced lung cancers and precancerous lesions in LACA mice. Green tea exerted an effect on the number of induced cancers and precancerous lesions, causing a drop of the cancerous rate from 79.75% to 13.59% and the number of lung tumor down to 1/7-1/16 that of the MNNG group, i.e. down to less than one tumor nodule per mouse.(ABSTRACT TRUNCATED AT 250 WORDS)
Luo
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Li
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D000236:Adenoma / Q000139:chemically induced / Q000517:prevention & control; D000818:Animals; D008175:Lung Neoplasms / Q000139:chemically induced / Q000517:prevention & control*; D008769:Methylnitronitrosoguanidine; D051379:Mice; D010936:Plant Extracts / Q000627:therapeutic use; D011230:Precancerous Conditions / Q000139:chemically induced / Q000517:prevention & control*; D013662:Tea
D010936:Plant Extracts; D013662:Tea; D008769:Methylnitronitrosoguanidine