Chinese medicinal herbs modulate mutagenesis, DNA binding and metabolism of benzo[a]pyrene 7,8-dihydrodiol and benzo[a]pyrene 7,8-dihydrodiol-9,10-epoxide
- PMID: 1540939
- DOI: 10.1016/0304-3835(92)90182-u
Chinese medicinal herbs modulate mutagenesis, DNA binding and metabolism of benzo[a]pyrene 7,8-dihydrodiol and benzo[a]pyrene 7,8-dihydrodiol-9,10-epoxide
Abstract
Oldenlandia diffusa(OD) and Scutellaria barbata (SB) have been used in traditional Chinese medicine for treating liver, lung and rectal tumors. In this study, the effects of aqueous extracts of these two herbs on benzo[a]pyrene 7,8-dihydrodiol. (BaP 7,8-DHD) and benzo[a]pyrene 7,8-dihydrodiol-9,10-epoxide (BPDE)-induced mutagenesis using Salmonella typhimurium TA100 as the bacterial tester strain and rat liver 9000 x g supernatant (S9) as the metabolic activation system were assessed. We also determined the effects of these two herbs on BaP 7,8-DHD and BPDE binding to calf thymus DNA. Organosoluble metabolites of BaP 7,8-DHD and water-soluble conjugates of BaP 7,8-DHD and BPDE were analyzed by high-performance liquid chromatography (HPLC) and alumina column liquid chromatography. Mutagenesis assays revealed that these two herbs produced a significant concentration-dependent inhibition of histidine-independent (His+) revertants induced by BaP 7,8-DHD and BPDE. OD and SB also inhibited BPDE-induced mutagenesis in a concentration-dependent manner in the absence of S9. SB had a greater inhibitory effect than OD. SB significantly inhibited BaP 7,8-DHD and BPDE binding to DNA while OD significantly enhanced DNA binding of both compounds. OD and SB inhibited the formation of organosoluble metabolites of BaP 7,8-DHD and decreased the formation of water-soluble conjugates of BaP 7,8-DHD and BPDE. However, the fraction of the total radioactivity in the water-soluble conjugates present as sulfate and glutathione was increased by OD and SB. Glucuronide fraction was decreased. The results of this study affirm our previous work suggesting that these two Chinese medicinal herbs possess antimutagenic properties and further suggest that they act as blocking agents through a scavenging mechanism.
Similar articles
-
Inhibition of liver microsome-mediated mutagenesis, metabolism and DNA-binding of benzo[a]pyrene and benzo[a]pyrene 7,8-dihydrodiol in the rat following glucose administration.Cancer Lett. 1990 Apr 20;50(2):149-56. doi: 10.1016/0304-3835(90)90245-s. Cancer Lett. 1990. PMID: 2109652
-
Modulation of cytochrome P-450IA1-mediated mutagenicity, DNA binding and metabolism of benzo[a]pyrene by Chinese medicinal herbs.Cancer Lett. 1993 Jan 15;68(1):75-82. doi: 10.1016/0304-3835(93)90222-u. Cancer Lett. 1993. PMID: 8422652
-
Chinese medicinal herbs modulate mutagenesis, DNA binding and metabolism of aflatoxin B1.Mutat Res. 1992 Jun 1;279(3):209-16. doi: 10.1016/0165-1218(92)90069-c. Mutat Res. 1992. PMID: 1377337
-
The dual effects of Benzo(a)pyrene/Benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide on DNA Methylation.Sci Total Environ. 2024 Nov 10;950:175042. doi: 10.1016/j.scitotenv.2024.175042. Epub 2024 Jul 29. Sci Total Environ. 2024. PMID: 39084379 Review.
-
DNA-carcinogen interaction: covalent DNA-adducts of benzo(a)pyrene 7,8-dihydrodiol 9,10-epoxides studied by biochemical and biophysical techniques.Q Rev Biophys. 1989 Feb;22(1):1-37. Q Rev Biophys. 1989. PMID: 2501820 Review. No abstract available.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources