Abstract
Magnoliae Flos (MF) is a traditional medicinal herb used for managing rhinitis, sinusitis and headache. The purpose of the present study was to determine the neuroprotective effect of MF against glutamate-induced oxidative stress and to assess the underlying mechanism. Glutamate is a major endogenous excitatory neurotransmitter in the brain and contributes to the development of neurodegenerative diseases by excessive activation. MF extract was subjected to a neuroprotective effect assay in HT22 mouse hippocampal cells. The mechanism underlying the neuroprotective effect of MF extract was evaluated by assaying reactive oxygen species (ROS) levels, intracellular Ca(2+) levels, mitochondrial membrane potential, glutathione level and antioxidant enzyme activity in HT22 cells. MF extract significantly decreased glutamate-induced death of HT22 cells (80.83 ± 7.34% relative neuroprotection). MF extract reduced the intracellular ROS and Ca(2+) levels and increased the glutathione level and glutathione reductase and glutathione peroxide activities. Moreover, MF extract attenuated the mitochondrial membrane potential in HT22 cells. These results suggested that MF extract exerts a neuroprotective effect against oxidative stress HT22 cells, which was mediated by its antioxidant activity.