Ginkgo biloba, DNA damage and DNA repair: Overview

Abstract

Despite the ancient use in Chinese popular medicine and, more recently, in western modern medicine in many European countries, the biological effects of extracts of G. biloba (GBE) are still not clearly known. In modern medicine GBE has been used for tinnitus, to reverse memory loss, for dementia, and Alzheimer's and Parkinson's diseases in elderly people. Besides reports on improvement of blood circulation in the brain, there are a number of studies pointing to complex cellular effects, involving signal transduction pathways and epigenetic modifications. Evidence are presented from recent reports concerning genotoxic and antigenotoxic properties and the corresponding mechanisms underlying such activities, mostly regarding the prooxidant and antioxidant activities of the extract. However, several examples of direct interaction of the extract and its components with specific proteins are provided, especially for DNA damage repair, contributing for antigenotoxicity. Evidence of epigenetic effects of GBE are also presented from approaches involving transcriptomics, detection of activity of histone deacetylases, and screening of plant extracts with cell-based systems for detection of posttranslational modifications. The modulation of chromatin-remodeling enzymes by GBE and their interaction with proteins involved in DNA damage repair, apoptosis, and signal transduction are discussed in the context of neurodegeneration.