Preventive Effect of Processed Hydrangea Leaf Extract on Acute Restraint-induced Stress via Brain-derived Neurotrophic Factor Signaling Pathway in C57BL/6 Mice

Abstract

Stress is a crucial determinant for maintenance of health and has been accompanied with neuropsychiatric disorders and abnormal behavioral symptoms. Processed Hydrangea Leaf is a traditional tea that has been used as a natural sweetening agent for food and has a meaning of 'Inner peace' in Buddhism. The aim of this study was to investigate the preventive effect of Processed Hydrangea Leaf extract (PHL) on mice against acute restraint-induced stress. Acute Restraint Stress (ARS) is widely used to evoke depression-like and anxiety-like behaviors in C57BL/6 mice. ARS induced traumatic behavior and higher corticosterone level in plasma compared with common state. Preadministration of PHL at dose of 0, 10, 50 mg/kg by daily gavage for 5 days decreased the immobility time in tail suspension test (TST), and increased locomotor activity in open field test (OFT). In both prefrontal cortex and hippocampus, the effects of PHL on the brain-derived neurotrophic factor (BDNF) signaling pathway were revealed that PHL reduced the increased BDNF levels in mice subjected to repeated restraint stress. In conclusion, Processed Hydrangea Leaf extract has a protective effect on acute restraint-induced stress via BDNF signaling pathway in mice.