Skip to Content
MilliporeSigma
  • Mechanistic evaluation of Ginkgo biloba leaf extract-induced genotoxicity in L5178Y cells.

Mechanistic evaluation of Ginkgo biloba leaf extract-induced genotoxicity in L5178Y cells.

Toxicological sciences : an official journal of the Society of Toxicology (2014-03-07)
Haixia Lin, Xiaoqing Guo, Suhui Zhang, Stacey L Dial, Lei Guo, Mugimane G Manjanatha, Martha M Moore, Nan Mei
ABSTRACT

Ginkgo biloba has been used for many thousand years as a traditional herbal remedy and its extract has been consumed for many decades as a dietary supplement. Ginkgo biloba leaf extract is a complex mixture with many constituents, including flavonol glycosides and terpene lactones. The National Toxicology Program 2-year cancer bioassay found that G. biloba leaf extract targets the liver, thyroid gland, and nose of rodents; however, the mechanism of G. biloba leaf extract-associated carcinogenicity remains unclear. In the current study, the in vitro genotoxicity of G. biloba leaf extract and its eight constituents was evaluated using the mouse lymphoma assay (MLA) and Comet assay. The underlying mechanisms of G. biloba leaf extract-associated genotoxicity were explored. Ginkgo biloba leaf extract, quercetin, and kaempferol resulted in a dose-dependent increase in the mutant frequency and DNA double-strand breaks (DSBs). Western blot analysis confirmed that G. biloba leaf extract, quercetin, and kaempferol activated the DNA damage signaling pathway with increased expression of γ-H2AX and phosphorylated Chk2 and Chk1. In addition, G. biloba leaf extract produced reactive oxygen species and decreased glutathione levels in L5178Y cells. Loss of heterozygosity analysis of mutants indicated that G. biloba leaf extract, quercetin, and kaempferol treatments resulted in extensive chromosomal damage. These results indicate that G. biloba leaf extract and its two constituents, quercetin and kaempferol, are mutagenic to the mouse L5178Y cells and induce DSBs. Quercetin and kaempferol likely are major contributors to G. biloba leaf extract-induced genotoxicity.

MATERIALS
Product Number
Brand
Product Description

Supelco
Benzo[a]pyrene solution, certified reference material, TraceCERT®, 1000 μg/mL in acetone
Supelco
Benzo[a]pyrene solution, certified reference material, TraceCERT®, 200 μg/mL in methylene chloride
Sigma-Aldrich
Quercetin, ≥95% (HPLC), solid
Sigma-Aldrich
Trypan Blue, ≥80% (HPLC), Dye content 60 %
Supelco
Ginkgolide C, analytical standard
Sigma-Aldrich
Kaempferol, ≥97.0% (HPLC)
Sigma-Aldrich
Trypan Blue, powder, BioReagent, suitable for cell culture
Sigma-Aldrich
Trifluorothymidine, ≥99% (HPLC)
Sigma-Aldrich
Kaempferol, ≥90% (HPLC), powder
Sigma-Aldrich
(−)-Bilobalide from Ginkgo biloba leaves, ≥93% (HPLC)
Supelco
Kaempferol, analytical standard
Supelco
Benzo[a]pyrene solution, 100 μg/mL in cyclohexane, analytical standard
USP
Quercetin, United States Pharmacopeia (USP) Reference Standard
Supelco
Quercetin, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Dimethyl sulfoxide, SAJ first grade, ≥99.0%
Sigma-Aldrich
Dimethyl sulfoxide, JIS special grade, ≥99.0%
Sigma-Aldrich
Dimethyl sulfoxide, ≥99.5%
Sigma-Aldrich
Dimethyl sulfoxide, ≥99.0%, suitable for absorption spectrum analysis
Sigma-Aldrich
Dimethyl sulfoxide solution, 50 wt. % in H2O
Sigma-Aldrich
Dimethyl sulfoxide, suitable for HPLC
Supelco
Ginkgolide B, analytical standard
Supelco
Benzo[a]pyrene, certified reference material, TraceCERT®, Manufactured by: Sigma-Aldrich Production GmbH, Switzerland
Supelco
Dimethyl sulfoxide, for inorganic trace analysis, ≥99.99995% (metals basis)
Supelco
Isorhamnetin, analytical standard
Sigma-Aldrich
8-Octanoyloxypyrene-1,3,6-trisulfonic acid trisodium salt, suitable for fluorescence, ≥90% (HPCE)
Supelco
Benzo[a]pyrene, analytical standard, for environmental analysis
Sigma-Aldrich
Trypan Blue solution, 0.4%, for microscopy
Sigma-Aldrich
4-Nitroquinoline N-oxide, ≥98%
Sigma-Aldrich
Trypan Blue solution, 0.4%, liquid, sterile-filtered, suitable for cell culture
Sigma-Aldrich
Benzo[a]pyrene, ≥96% (HPLC)