Abstract
Epimedii Herba (EH) has been used in traditional Asian medicine to treat hemiplegia
following stroke. Icariin, its major active component, is used as a quality-control
marker and for its various pharmacological effects. We hypothesized that icariin would
show protective effects following traumatic brain injury (TBI). The TBI mouse model
was induced using a controlled cortical impact method. Body weight, brain damage,
motor function, and cognitive function were evaluated. Synaptogenesis markers were
analyzed to investigate potential mechanisms of action. The animals were divided into
six groups: sham, control, minocycline-treated group, and icariin-treated (3, 10,
and 30 mg/kg, p. o.) groups. The icariin 30 mg/kg-treated group regained body weight
at 7 and 8 d post TBI. Icariin 30 mg/kg- and 10 mg/kg-treated groups showed enhanced
sensory-motor function at 8 d post TBI in rotarod and balance beam tests. Icariin-treated
groups showed increased recognition index in the novel object recognition test at
all doses and increased spontaneous alternation in the Y-maze test at 30 mg/kg. Icariin
upregulated brain-derived neurotrophic factor, synaptophysin and postsynaptic density
protein 95 expressions. However, no protective effects against brain damage or neuronal
death were observed. The current results provide a basis for using icariin following
TBI and suggest that it could be a candidate for the development of therapeutic agents
for functional recovery after TBI.
Key words
icariin - Epimedii Herba - traumatic brain injury - synaptic plasticity - functional
recovery - Berberidaceae
