Extract of Ginkgo biloba induces glutathione-S-transferase subunit-P1 in vitro

Abstract 

The extract of Ginkgo biloba (EGb), containing 24% flavone glycosides and 6% terpenoids, is widely used to treat early-stage Alzheimer's disease, vascular dementia, peripheral claudication and vascular tinnitus. Its remarkable antioxidant activity has recently been demonstrated in both cell lines and animals. Glutathione-S-transferases (GSTs) are a class of important detoxification enzymes in the antioxidant system and GST-P1 is the major GST isoform highly expressed in human tissues. Over expression of GST-P1 protected prostate cells from cytotoxicity and DNA damage by the heterocyclic amine carcinogen, while inhibition of expression of GST-P1 by transfecting GST-P1 antisense cDNA or targeted deletion of GST-P1 has been found to sensitize cells to cytotoxic chemicals. It is obvious that induction of GST-P1 expression should be a promising alternative for chemoprevention. The present study aimed to investigate the induction effect of EGb on GST-P1 in HepG2 and Hep1c1c7 cell lines and found that GST-P1 was increased both at the expression and enzyme activity levels.

Keywords: Extract of Ginkgo biloba, Glutathione-S-transferase-subunit-P1 (GST-P1), Herb

Abbreviations: EGb, extract of Ginkgo biloba, GST-P1, glutathione-S-transferase subunit-p1, ARE, antioxidant response element, Nrf2, nuclear factor erythroid 2-related factor 2, Keap1, Kelch-like ECH-associated protein 1