Coriandrum sativum Suppresses Aβ42-Induced ROS Increases, Glial Cell Proliferation, and ERK Activation

Alzheimer's disease (AD), the most common neurodegenerative disease, has a complex and widespread pathology that is characterized by the accumulation of amyloid β-peptide (Aβ) in the brain and various cellular abnormalities, including increased oxidative damage, an amplified inflammatory response, and altered mitogen-activated protein kinase signaling. Based on the complex etiology of AD, traditional medicinal plants with multiple effective components are alternative treatments for patients with AD. In the present study, we investigated the neuroprotective effects of an ethanol extract of Coriandrum sativum (C. sativum) leaves on Aβ cytotoxicity and examined the molecular mechanisms underlying the beneficial effects. Although recent studies have shown the benefits of the inhalation of C. sativum oil in an animal model of AD, the detailed molecular mechanisms by which C. sativum exerts its neuroprotective effects are unclear. Here, we found that treatment with C. sativum extract increased the survival of both Aβ-treated mammalian cells and Aβ42-expressing flies. Moreover, C. sativum extract intake suppressed Aβ42-induced cell death in the larval imaginal disc and brain without affecting Aβ42 expression and accumulation. Interestingly, the increases in reactive oxygen species levels and glial cell number in AD model flies were reduced by C. sativum extract intake. Additionally, C. sativum extract inhibited the epidermal growth factor receptor- and Aβ-induced phosphorylation of extracellular signal-regulated kinase (ERK). The constitutively active form of ERK abolished the protective function of C. sativum extract against the Aβ42-induced eye defect phenotype in Drosophila. Taken together, these results suggest that C. sativum leaves have antioxidant, anti-inflammatory, and ERK signaling inhibitory properties that are beneficial for patients with AD.