The Protective Effects of Lycium Barbarum Polysaccharides on Transient Retinal Ischemia

Retinal ischemia/reperfusion (I/R) injury leads to irreversible neuronal death, glial activation, retinal swelling and oxidative stress. It is a common feature in various ocular diseases, such as glaucoma, diabetic retinopathy and amaurosis fugax. In the present study, we aimed to evaluate the effects of Lycium Barbarum Polysaccharides (LBP) in a murine retinal I/R model. Mice were orally treated with either vehicle (PBS) or LBP (1mg/kg) daily for 1 week before induction of retinal ischemia. Retinae were collected after 2 hours ischemia and 22 hours reperfusion. Paraffin-embedded sections were prepared for immunohistochemical analyses. Significantly fewer viable cells were found in vehicle-treated retinae comparing to LBP group. This finding was further confirmed by TUNEL assay where significantly fewer apoptotic cells were identified in LBP-treated retinae. Additionally, retinal swelling induced by retinal I/R injury in the vehicle-treated group was not observed in LBP-treated group. Moreover, intense GFAP immunoreactivity and IgG extravasation were observed in vehicle-treated group but not in LBP treated group. The results showed that pre-treatment with LBP was protective in retinal I/R injury via reducing neuronal death, apoptosis, retinal swelling, GFAP activation and blood vessel leakage. LBP may be used as a preventive agent for retinal ischemia diseases.