Neuroprotective effect of progesterone in newborn rats with hypoxic-ischemic encephalopathy

Abstract

Progesterone (PROG) is a type of neurosteroid, and it has physiological functions in the central nervous system. To date, most researches into progesterone have focused on its application in treatment of traumatic brain injury, stroke and neurodegenerative disorders, but its effect on hypoxic-ischemic encephalopathy (HIE) remains unclear. In the current study, we investigated the effect of exogenous progesterone in HIE newborn rats. Newborn Wistar rats were divided into the sham-operated group, hypoxic-ischemic (HI) group and the pretreated group with PROG to observe the effects of progesterone on the components in cortex and hippocampus. Our results showed that the levels of water, sodium, calcium, NO (nitric oxide) and glycogen synthatase kinase-3β (GSK-3β) in brain tissues were increased significantly in HI group compared to those in the sham-operated group except for significantly lower concentration of potassium while those in PROG pretreated group were lower significantly than those in HI group. The cell apoptosis rate and the concentration of malondialdehyde (MDA) in HI group were higher significantly than those in the sham-operated group or the pretreated group while superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities in HI group were lower significantly than those in any other two groups. Exogenous PROG can obviously reduce neuron apoptosis, oxygen free radical production, down-regulate the expression of glial fibrillary acidic protein (GFAP) and up-regulate the expression of PROG receptor (PR) after brain injury. Key words: Progesterone, hypoxic-ischemic encephalopathy, newborn rats, neuroprotection.