Abstract
Purpose :
Hericium erinaceus polysaccharide (HEP) is a traditional Chinese medicine. HEP can significantly decrease lipid peroxidation level and increase activity of antioxidant enzymes in experimental animals. We aimed to test whether the HEP has neuroprotective effects in an experimental of optic nerve (ON) crush in rats.
Methods :
The ONs of adult male Wistar rat (150-180 g) were crushed by a standardized method. The normal control eyes received a sham operation. Different dosages of HEP extract (200, 100, and 50 mg/Kg) or phosphate-buffered saline (PBS control, 200 μL) was immediately administered by daily gavage for 2 weeks after ON crush. RGC density was counted by retrograde labeling with FluoroGold, and visual function was assessed by flash visual evoked potentials (fVEP). We used TUNEL assay to evaluate RGC apoptosis in the retinas and immunohistochemistry of ED1 stain in ON sections to evaluate the presence of extrinsic macrophage.
Results :
Two weeks after the insult, the RGC densities in the 200 and 100 mg/kg of HEP extract-treated groups were significantly higher (982.6±208.3/mm2 and 772.2±214.7/mm2) than that of the PBS-treated group (370.7±167.79/mm2). The fVEP analysis showed the higher amplitude of the P1-N2 wave in the 200 and 100 mg/kg of HEP extract-treated groups (23.7±8.7 μV and 28.8±4.8 μV) than the PBS-treated group (8.3±2.7 μV). TUNEL positive cells were significantly reduced 3.23- and 2.08-fold in the 200 and 100 mg/kg of HEP extract-treated groups compared to the PBS-treated group (p<0.05). Treatment with 200 and 100 mg/kg of HEP extract significantly decreased 3.96- and 2.44-fold of ED1-positive cells compared to treatment with PBS (p<0.05).
Conclusions :
These results demonstrated that HEP extract protects RGCs and helps preserve the visual function in the rat model of ON crush. HEP extract provides neuroprotective effects via anti-apoptotic action on RGCs and anti-inflammation by reducing extrinsic macrophage infiltration into ON in the ON crush injury.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.