Chromosomal Aberrations and Sister Chromatid Exchanges in Cultured Human Lymphocytes IV. Concluding Remarks

抄録

It has been widely recognized that food factors play a significant role in carcinogenesis. This has led us to investigate chromosomal aberrations (CA) and SCE's inducing potentiality of black tea (BT), green tea (GT), epigallocatechingallate (EGCG) and ascorbic acid (AA) (See part I, II and III). On the basis of quantitative ratio of EGCG in BT and GT it seems that SCE enhancing effect of BT and GT after treatment ‘A’ is not entirely due to the presence of EGCG. They may contain some other factor (s) which diminish the DNA damaging potentiality of EGCG. BT and GT seems to contain different active factor (s) which may have different mode of actions because treatment ‘B’ of GT decreased the SCE frequency like EGCG, while treatment ‘B’ of BT significantly enhanced the SCE's and aberrant metaphases.
An effort was made to know correlation between CA and SCE's. Various studies have been discussed. The results of present study support our earlier view that positive correlation between these biological end points seems specific and may depend upon the type of mutagens and their mode of action. The present study further suggests that the cell cycle's stage in which cells are treated or exposed to a mutagen also play a significant role in sharing common DNA lesions for the manifestation of CA and SCE's.
On the basis of significant correlation coefficient ‘r’ value between aberrant metaphases (including chromatid gap) and mean SCE/cell and negative ‘r’ value between them (after deleting chromatid gap) after treatment ‘A’ of EGCG, it has been suggested that chromatid gap should not be excluded in scoring chromosomal aberrations.