[Antitransforming activity of chlorophyllin against trans-benzo(a)pyrene-trans-7,8-dihydrodiol-9,10-epoxide].
OBJECTIVE
To study the inhibitory effect of chlorophyllin (CHL) on trans-benzo(a)pyrene-trans-7,8-dihydrodiol-9,10-epoxide (BPDE) induced malignant transformation in human bronchial epithelial cell line (16HBE).


METHODS
10, 50 or 100 micro mol/L CHL were added into the media during the cells transformation induced by BPDE, and the malignant degree of transformed cells were identified by the ConA agglutination test and the assay for anchorage-independent growth and tumorigenicity.


RESULTS
After the cells were cultured for 25 times, the time of cells agglutination in groups treated with both CHL and BPDE was increased significantly; the colony formation efficiency in soft agar in groups treated with both CHL and BPDE (7.4 per thousand, 11.4 per thousand and 14.4 per thousand ) showed significant decrease (P < 0.05) in dose-dependent manner, as compared with that in group treated with BPDE alone (19.6 per thousand ). Cells treated with both CHL and BPDE or BPDE alone developed tumor in nude mice, a squamous carcinoma confirmed by histopathological examination. The volume of tumor in groups treated with both CHL and BPDE (0.43 +/- 0.13) cm(2), (0.22 +/- 0.04) cm(2) and (0.10 +/- 0.06) cm(3) was significantly smaller (P < 0.05) and dose-dependent, as compared with that in the group treated with BPDE alone (1.71 +/- 0.37) cm(3).


CONCLUSIONS
CHL showed significant antitransforming ability in human bronchial epithelial cell line induced by BPDE.
Ji
Wei-Dong
WD
Institute for Chemical Carcinogenesis, Guangzhou Medical College, Guangzhou 510182, China.
Jiang
Yi-Guo
YG
Wang
Min
M
Feng
Su-Mei
SM
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000633:toxicity*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D002735:Chlorophyllides / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009374:Neoplasms, Experimental / Q000517:prevention & control
D016588:Anticarcinogenic Agents; D002735:Chlorophyllides; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; C007020:chlorophyllin