Fig. 7. Schematic representation of GardeninA-mediated neuroprotection against PQ-induced PD phenotypes in Drosophila.

PQ exposure induces oxidative stress and leads to the activation of genes involved in the neuroinflammatory pathways, including Relish and nitric oxide in adult male flies. Furthermore, it activates the proapoptotic responses leading to PD symptoms involving increased mortality, mobility defects and progressive demise of dopaminergic neurons. The flavonoid, GardeninA confers protection against PQ-induced neurotoxicity by inhibiting the neuroinflammatory and the cellular death response pathways, thereby providing protection against PD like symptoms. Interestingly, the antioxidant activity of GardeninA alone is not sufficient to provide protection against PQ-induced neurotoxicity. GardeninA acts on multiple pathways that are commonly associated with PD pathogenesis to reduce the neurotoxic impact of PQ in adult flies. Therefore, Gardenin A can be a potential multifactorial therapeutic for the prevention of PD caused by environmental toxins.