Pyrocatechol

Exposure related observations in humans: other data

Administrative data

Endpoint:

exposure-related observations in humans: other data

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Remarks:

This test was not performed according to standardised guidelines, but is well described.

Data source

Reference

Reference Type:

publication

Title:

Wine antioxidant polyphenols inhibit the proliferation of human prostate cancer cell lines

Author:

Kampa M., Hatzoglou A., Notas G., Damianaki A., Bakogeorgou|E., Gemetzi C., Kouroumalis E., Martin P.-M., Castanas E.

Year:

2000

Bibliographic source:

Nutrition and Cancer, 37(2) 223-233.

Materials and methods

Type of study / information:

The effect of catechol on the growth of 3 prostate cancer cell lines (LNCaP, PC3, and DU145) was investigated.

Endpoint addressed:

carcinogenicity

Principles of method if other than guideline:

The effect of catechol on 3 prostate cancer cell lines proliferation

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Pyrocatechol

EC Number:

204-427-5

EC Name:

Pyrocatechol

Cas Number:

120-80-9

Molecular formula:

C6H6O2

IUPAC Name:

pyrocatechol

Details on test material:

Concentrated desalcoholised wine was prepared by vacuum distillation followed by evaporation. Wine polyphenolic extract was produced by resin adsorption of total polyphenols followed by ethanolic elution and evaporation.
(+)-catechol was prepared from the total polyphenolic extract by semipreparative high pressure liquid chromatography with use of RP18 column and assayed by ultraviolet visible spectroscopy
- Purity > 99 % (NMR at 500 MHz) - Diluted in Phosphate buffer saline (PBS).

Method

Ethical approval:

not specified

Exposure assessment:

measured

Details on exposure:

* Cell viability and growth assay:
Cells were cultured for a total of 5 days in presence of catechol. Cell growth and viability were measured by the tetrazolium salt assay.
All experiments were performed at least 3 times in triplicates.

* H2O2 treatment:
Cells were seeded in 24-well plates at an initial density of 1.5 x 10E5 cells/well. After 24 h, medium was replaced, FBS was omitted, and catechol was introduced (10E-8 M). 24 h later, medium containing different concentrations of H2O2 (0.05-5.0 mM) was provided. After 3 h at 37 °C cells were washed with PBS and their viability was determined.

* Reactive Oxygen species generation was determined by flow cytometry.

* Androgen binding assay: LNCaP cells (1.5 x 10E5) were seeded in 24-well plates. After 24 h, binding was performed on whole cells in serum-free PBS. 435 fmol of [3H]testosterone were introduced in 50 µl PBS, together with non labelled testosterone and catechol (10E-12 to 10E-6 M).
After overnight exposure, the bound radioactivity was counted in scintillation counter. Binding was repeated at least 3 times in duplicates.

* Determination of NO production and the determination of inducible NO synthase activity were also performed.

Results and discussion

Results:

* Cell proliferation:
Catechol was found to significantly inhibit the proliferation of PC3 cells. LNCaP cells were less sensitive to this effect. In DU145 cells, catechol produced only partial inhibition.
* Catechol acts preferentially on the two cell lines possessing non-functional (PC3) or functional (LNCaP) androgen receptor. Results of competition experiments indicate that catechol is a very weak competitor of androgen binding.
* Preincubation with catechol resulted in an increased resistance of DU145 and PC3 cells to H2O2 toxicity. In LNCaP cells, this effect was observed only at H2O2 concentrations < 1 mM.
* Production of ROS: In PC3 cells, a significant decrease of ROS production was observed. At long incubation time (> 40 min), this effect was also observed in the DU145 cell line.
LNCaP cells did not show any modification of ROS production after catechol preincubation.
* Production of NO: Catechol decreases the production/secretion of NO.

Applicant's summary and conclusion

Conclusions:

Negative.