Effect of lycium barbarum polysaccharides of apoptosis and autophagic death in primary cultured hippocampal neurons injured by oxygen glucose deprivation and reoxygenation

Objective To investigate the effect of lycium barbarum polysaccharides (LBP) on apoptosis and autophagic death in primary cultured hippocampal neurons after oxygen glucose deprivation and reoxygenation (OGD/R) injury. Methods Primary cultured hippocampal neurons were exposed to OGD/R. The cells were randomly divided into 5 groups: control group, OGD/R group, and OGD/R+LBP groups (15, 30 and 60 μg/mL LBP). The cell viability was assessed by MTT assay. The cell damage was evaluated through detecting the lactate dehydrogenase (LDH) release rate. Apoptosis rate was detected by TUNEL, and cleaved Caspase-3 was identified by immunofluorescence staining. Protein expression was detected by Western blotting. Results As compared with the control group, OGD/R group had significantly decreased cell viability (P<0.05); and significantly increased cell viability and decreased LDH release rate were noted in the LBP (15, 30 and 60 μg/mL) treatment groups as compared with those in the OGD/R group (P<0.05). The 60 μg/mL LBP treatment group had significantly smaller number of TUNEL-positive cells than the OGD/R group(P<0.05). Immunofluorescence staining and Western blotting both revealed that 60 μg/mL LBP treatment group had significantly decreased Beclin1 level and ratio of cleaved Caspase-3/Caspase-3 and ratio of microtubule-associated protein light chain (LC)3II/LC3I, and statistically increased p62 level and ratio of Bcl-2/Bax as compared with OGD/R group (P<0.05). Conclusion LBP treatment protects primary hippocampal neurons from OGD/R injury via inhibiting apoptosis and autophagic cell death. Key words: Lycium barbarum polysaccharide; Hippocampal neuron; Oxygen glucose deprivation and reperfusion; Autophagy death; Apoptosis