๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Effect of dietary chlorophyll derivatives on mutagenesis and tumor cell growth

โœ Scribed by Simon Chernomorsky; Alvin Segelman; Ronald D. Poretz


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
115 KB
Volume
19
Category
Article
ISSN
0270-3211

No coin nor oath required. For personal study only.

โœฆ Synopsis


Much attention in recent years has been given to the antigenotoxicity of chlorophyll. Chlorophyll, however, is known to be converted into pheophytin, pyropheophytin, and pheophorbide in processed vegetable food and following ingestion by humans. Studies were conducted on the antimutagenic and tumoricidal potencies of these compounds. All the chlorophyll derivatives tested exhibit identical antimutagenic effect towards 3-methylcholanthrene (3-MC), suggesting that the porphyrin nucleus may complex directly with the mutagen. It does not exclude, however, another mechanism of activity involving inactivation the enzymatic transformation of 3-MC. In contrast, the action of Nโ€ฒ-nitro-Nโ€ฒ-nitrosoguanidine (MNNG) depends upon structural differences between the chlorophyll derivatives. It is significantly lower when the phytol-containing pheophytin and pyropheophytin are tested as to that of the phytol-lacking pheophorbide. The higher concentrations of the chlorophyll derivatives were required to reduce the mutagenicity of MNNG than needed for 3-MC. The cytotoxicity of chlorophyll derivatives against tumor cells also was evaluated. The cellular uptake and inhibition of myeloma cell multiplicity were found to be greater for pheophorbide than for pheophytin. Calculated on the amount of cell associated chlorophyll derivative, however, pheophytin was more cytostatic/cytotoxic than pheophorbide. The results presented in this report indicate that food sources that yield chlorophyll derivatives may play a significant role in cancer prevention.


๐Ÿ“œ SIMILAR VOLUMES


Effects of conformationally restricted s
โœ Shujian Wu; Dongmei Zhang; Anne Donigan; Marcia I. Dawson; Dianne Robert Soprano ๐Ÿ“‚ Article ๐Ÿ“… 1998 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 151 KB ๐Ÿ‘ 1 views

We have used conformationally restricted retinoids to investigate the role of individual RAR subtypes and RXR in mediating the growth response of ovarian tumor cells to retinoids. Our results show that treatment of all-trans-RA-sensitive CAOV-3 cells with retinoids that bind and activate a single RA

Effect of combined adoptive immunotherap
โœ R. Sumareva; G. Ukrainsky; L. Kiremidjian-Schumacher; M. Roy; H.I. Wishe; A.D. S ๐Ÿ“‚ Article ๐Ÿ“… 1999 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 352 KB ๐Ÿ‘ 2 views

Advanced squamous cell carcinomas of the head and neck are difficult to control despite optimal surgery, radiotherapy and/or chemotherapy, and the tumors are usually not immunogenic. Because of the anatomic accessibility of the tumors, local adoptive immunotherapy of these tumors is feasable and may

Effect of farnesyltransferase overexpres
โœ Toshihiko Nagase; Sumio Kawata; Hiromu Nakajima; Shinji Tamura; Eiji Yamasaki; K ๐Ÿ“‚ Article ๐Ÿ“… 1999 ๐Ÿ› John Wiley and Sons ๐ŸŒ French โš– 275 KB ๐Ÿ‘ 2 views

A series of studies using farnesyltransferase (FTase) inhibitors that the inhibition of FTase function suppresses the growth of ras-transformed cells in vitro and in vivo. However, whether FTase is directly involved in the regulation of cell proliferation remains to be demonstrated. To investigate w

Effect of growth factors and antigen on
โœ Gregory Dandulakis; John C. Herr; Donald J. Kirwan ๐Ÿ“‚ Article ๐Ÿ“… 1997 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 179 KB ๐Ÿ‘ 2 views

The cell growth and monoclonal antibody production kinetics of hybridoma cell cultures continuously exposed to growth factors and the cognate antigen were investigated. The growth factors were the epidermal growth factor, fibroblast growth factor, and interleukin-2, whereas the antigen was the trini