Protective Effect of Ginkgo biloba (Ginkgoaceae Family) Leaf Extracts on Female Drosophila melanogaster Suffering from Ultraviolet Irradiation through Activating the Keap1-Nrf2 Signaling Pathway

Ginkgo biloba leaf extracts (GBLE) possess strong physiological activities, such as antioxidant and anti-inflammatory effects. In the experiment, the mitigating effects of GBLE on ultraviolet (UV) radiation-induced damage were studied in female Drosophila melanogaster (D. melanogaster). Based on the concentration screening experiments, GBLE was finally added to the food medium at a concentration of 0.04 mg/mL to ameliorate the damage to female D. melanogaster suffering from the irradiating dose (300 μW/cm³, 40 cm, 50 min). The results indicated that the mean lifespan of D. melanogaster fed GBLE food was increased by 5.80% in comparison with that of the control group, and the climbing ability was increased by 69.79% with antioxidant capacity improvement, including a reduction in ROS levels in the fat body. Additionally, GBLE could also promote the recovery of cyclogeny and fertility of UV-damaged D. melanogaster. The gene expression levels in the Keap1-Nrf2 signaling pathway were significantly promoted in female D. melanogaster suffering from UV radiation with GBLE supplementation, and according to the Nrf2-RNAi D. melanogaster experiments, GBLE ameliorated the effect of UV damage through activating the Keap1-Nrf2 signaling pathway.