Flavonoid-rich extract of Toxicodendron vernicifluum served as a natural neuroprotective agent

Abstract

Lacquer tree [Toxicodendron vernicifluum (Stokes) F. A. Barkley Stokes], an economically important tree species that contains flavonoids as its major biologically active constituents, is mainly used to produce raw lacquers. Due to its sizeable production, the accumulation of byproducts is extensive, especially of older trees that cannot produce raw lacquers. It is considerable to develop new applications for these waste materials. Herein, a flavonoid-rich extract from the heartwood of T. vernicifluum (FRET) was prepared, and its potent in vitro neuroprotective properties against H2O2-induced oxidative injury in SH-SY5Y cells were demonstrated for the first time. The main components of FRET were determined by UF-HPLC-QTOF/MS, and the underlying mechanism of the neuroprotective effect was revealed. The results showed that FRET pretreatment significantly attenuated H2O2-induced cell apoptosis in a dose-dependent manner by lowering ROS production and increasing the mitochondrial membrane potential. Mechanistically, the neuroprotective effects of FRET were confirmed to be associated with Nrf2/HO-1, PI3K/Akt/mTOR-GSK3β, IL-6/Src-Stat3 and MAPK pathways. This study suggested that FRET with promising neuroprotective properties might be developed as a functional food or potential drug candidate for the prevention or treatment of diseases caused by oxidative stress and also provided a novel strategy for the comprehensive utilization of T. vernicifluum.