Ginkgo biloba L. Leaf Extract Protects HepG2 Cells Against Paraquat-Induced Oxidative DNA Damage
Department of Biology and Environment, University of Trás-os-Montes e Alto Douro (ECVA, UTAD), Quinta de Prados, 5001-801 Vila Real, Portugal
Centre for the Research and Technology of Agro-Environmental and Biological Sciences, (CITAB-UTAD), Quinta de Prados, 5001-801 Vila-Real, Portugal
Department of Genetic and Biotechnology, (ECVA, UTAD), Quinta de Prados, 5001-801 Vila-Real, Portugal
Research Center in Sports, Health Sciences and Human Development, ECVA, UTAD, Quinta de Prados, 5001-801 Vila Real, Portugal
National Health Institute Dr. Ricardo Jorge (INSA), Rua Alexandre Herculano 321, 4000-055 Porto, Portugal
EPIUnit—Instituto de Saúde Pública da Universidade do Porto, Rua das Taipas, 135, 4050-091 Porto, Portugal
BioISI—Biosystems & Integrative Sciences Institute, University of Trás-os-Montes and Alto Douro (BioISI-UTAD), Quinta de Prados, 5000-801 Vila Real, Portugal
The Veterinary and Animal Research Centre, (CECAV-UTAD), 5000-801 Vila Real, Portugal
Authors to whom correspondence should be addressed.
Plants 2019, 8(12), 556; https://doi.org/10.3390/plants8120556
Received: 25 October 2019 / Revised: 23 November 2019 / Accepted: 27 November 2019 / Published: 29 November 2019
(This article belongs to the Special Issue Bioactive Compounds in Plants)
Ginkgo biloba L. leaf extracts and herbal infusions are used worldwide due to the health benefits that are attributed to its use, including anti-neoplastic, anti-aging, neuro-protection, antioxidant and others. The aim of this study was to evaluate the effect of an aqueous Ginkgo biloba extract on HepG2 cell viability, genotoxicity and DNA protection against paraquat-induced oxidative damage. Exposure to paraquat (PQ), over 24 h incubation at 1.0 and 1.5 µM, did not significantly reduce cell viability but induced concentration and time-dependent oxidative DNA damage. Ginkgo biloba leaf extract produced dose-dependent cytotoxicity (IC50 = 540.8 ± 40.5 µg/mL at 24 h exposure), and short incubations (1 h) produced basal and oxidative DNA damage (>750 and 1500 µg/mL, respectively). However, lower concentrations (e.g., 75 µg/mL) of Ginkgo biloba leaf extract were not cytotoxic and reduced basal DNA damage, indicating a protective effect at incubations up to 4 h. On the other hand, longer incubations (24 h) induced oxidative DNA damage. Co-incubation of HepG2 cells for 4 h, with G. biloba leaf extract (75 µg/mL) and PQ (1.0 or 1.5 µM) significantly reduced PQ-induced oxidative DNA damage. In conclusion, the consumption of Ginkgo biloba leaf extract for long periods at high doses/concentrations is potentially toxic; however, low doses protect the cells against basal oxidative damage and against environmentally derived toxicants that induce oxidative DNA damage.