Protective Mechanism of Lycium barbarum Polysaccharide (LBP) on H₂O₂-Induced Apoptosis of Human Epithelium Retinal Pigment Cells

Lycii fructus boasts a rich heritage of medicinal usage in China. Lycium barbarum polysaccharide (LBP) has demonstrated a diverse range of biological effects, such as eye protection, anti-aging, anti-oxidation, regulating the immune system, nerve protection, cell protection and anti-tumor properties. However, there is limited research regarding the potential of LBP to protect human RPE cells from apoptotic cell death induced by hydrogen peroxide (H 2 O 2 ). The study aims to examine how LBP protects human RPE cells from apoptotic induced by H 2 O 2 . The oxidative damage model of RPE cells induced by H 2 O 2 was established, and then investigate the impact of LBP at 10 μ mol/L and 100 μ mol/L on the RPE activity, the proportion of apoptotic cells and the apoptotic-relevant proteins expression under the action of H 2 O 2 . RPE cells were divided into four groups: blank control group (AG), oxidant damage group (OG), low concentration of LBP group (GL, 10 μ mol/L LBP), high concentration of LBP group (GH, 100 μ mol/L LBP). The findings revealed that compared to the AG group, the cell survivorship decreased in the OG group, but increased following intervention by different concentrations of LBP, indicating a substantial difference ( P <0.05). The apoptosis results indicated a significant increase in the OG in opposition to the AG ( P < 0.05). When comparing the GH to the GL, there was a downward trend in the apoptotic rate ( P < 0.05). In comparison to GL group, the apoptosis rate of GH showed a downward trend ( P < 0.05). Furthermore, the Bax protein and Caspase-3 expression increased, while Bcl-2 expression decreased significantly in the OG group compared to the AG ( P <0.01). Both the GL and GH groups showed a decrease in the Bax protein and Caspase-3, while BCL-2 increased significantly when opposed to the OG ( P <0.01). The GH group demonstrated a downward trend in the Bax and Caspase-3, while the Bcl-2 protein showed an upward trend ( P <0.05). Compared to the AG group, the OG demonstrated a decrease in Bcl-2 mRNA and an increase in Bax mRNA expression. The GL group showed higher Bcl-2 mRNA and lower Bax mRNA expression compared to the OG group. The GH group exhibited mRNA levels of Bcl-2 and Bax that were between the OG and GL groups ( P <0.05). These findings suggest that LBP can prevent H 2 O 2 -induced apoptosis of RPE cells and holds potential value in the treatment of dry AMD.