Sarkar D, Sharma A, Talukder G
Department of Botany, University of Calcutta, India.
Environ Mol Mutagen. 1996;28(2):121-6. doi: 10.1002/(SICI)1098-2280(1996)28:2<121::AID-EM8>3.0.CO;2-I.
Dietary consumption of green vegetables has been associated with protection against mutagenic and clastogenic activity of genotoxicants. Chlorophyll, being present in all green plants, had earlier been suggested to be the principal factor involved. Mice were administered (i) crude aqueous extract of leaf of Indian spinach, Beta vulgaris L. var.benghalensis Hort., and equivalent amounts of (ii) chlorophyll extracted from the leaf; (iii) purified chlorophyll, (iv) chlorophyllin, a sodium-copper derivative of chlorophyll; daily for 7 days. On day 7, one set of mice from each treatment was administered potassium dichromate-a known metallic clastogen. The mice were sacrificed after 24 hours. Chromosome preparations were made from bone marrow following the usual colchicine-air dry-Giemsa schedule. The cytogenetic endpoints scored were chromosomal aberrations and damaged cells. Crude leaf extract and chlorophyllin were nonclastogenic and reduced the clastogenic effects of potassium dichromate to the control distilled water level. Chlorophyll alone, whether extracted from the leaf or obtained in commercially purified form, was clastogenic and could reduce the effects of the chromium salt only to its own level. The protective action of the crude leaf extract may be attributed to the total effect of the interaction between the different components within the leaf extract, in which the clastogenicity of chlorophyll had been neutralized.
食用绿色蔬菜与预防遗传毒性物质的诱变和断裂活性有关。叶绿素存在于所有绿色植物中,此前曾被认为是其中的主要相关因素。给小鼠每日喂食(i)印度菠菜(Beta vulgaris L. var.benghalensis Hort.)叶片的粗水提取物以及等量的(ii)从叶片中提取的叶绿素;(iii)纯化的叶绿素,(iv)叶绿酸,一种叶绿素的钠铜衍生物,持续7天。在第7天,给每组处理中的一组小鼠施用重铬酸钾——一种已知的金属断裂剂。24小时后处死小鼠。按照常规的秋水仙素-空气干燥-吉姆萨染色程序,从骨髓制备染色体标本。所记录的细胞遗传学终点指标为染色体畸变和受损细胞。粗叶提取物和叶绿酸无断裂活性,并将重铬酸钾的断裂活性降低至对照蒸馏水水平。单独的叶绿素,无论是从叶片中提取还是以商业纯化形式获得,都具有断裂活性,并且只能将铬盐的作用降低到其自身的水平。粗叶提取物的保护作用可能归因于叶提取物中不同成分之间相互作用的总体效果,其中叶绿素的断裂活性已被中和。