Developing a high-throughput system for the screening of cytochrome P450 1A1--inhibitory polyphenols.

Polycyclic aromatic hydrocarbons (PAH) are established procarcinogens that can be found in our environment. The carcinogenicity of these compounds is initiated by their metabolic intermediates, and the extent of biotransformation determines the amount of reactive intermediates generated. CYP1A1 is a major enzyme that metabolizes PAH into carcinogenic moieties.

Screening of chemopreventive tea polyphenols against PAH genotoxicity in breast cancer cells by a XRE-luciferase reporter construct.

Polycyclic aromatic hydrocarbons (PAHs) are established cancer initiators that can be found in our food and environment. Some dietary plant polyphenols are strong inhibitors to PAH-induced mutagenesis, whereas others may not be as effective. To identify the chemopreventive compounds from a huge volume of dietary components, the development of an efficient screening method is required.

A potential protective mechanism of soya isoflavones against 7,12-dimethylbenz[a]anthracene tumour initiation.

Epidemiological studies indicate that Asian women have a lower breast cancer incidence compared with their counterparts in the West, and the difference has been related to soya consumption. Animal studies have suggested that soya may prevent dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis in the breast. In the present study a cell culture model was developed to address the effect of soya isoflavones on the DMBA-induced DNA damage.

The red clover (Trifolium pratense) isoflavone biochanin A modulates the biotransformation pathways of 7,12-dimethylbenz[a]anthracene.

Several flavonoids have shown their anti-carcinogenic effects in various models. The soyabean isoflavone genistein was demonstrated earlier in our laboratory to be an effective inhibitor of dimethylbenz[a]anthracene (DMBA)-induced DNA damage in MCF-7 cells by curbing cytochrome P450 (CYP) 1 enzymes. The red clover (Trifolium pratense) isoflavone biochanin A is a methylated derivative of genistein, and its anti-mutagenic effect in bacterial cells has been shown previously.

Are herbal medicinal products less teratogenic than Western pharmaceutical products.

Aim: To determine the use and teratogenicity of herbal medicinal products (HMP).

Methods: A retrospective study was conducted in a University hospital to compare the difference in the pattern of use and fetal outcomes between pregnant women who took HMP and Western pharmaceutical products (WPP).

Results: From 1995 Jan to 2001 Dec, 61 and 372 women took HMP and WPP one month before or during their current pregnancies respectively.