Abstract: Objective: The aim of this study was to explore the protective effect of dolichos bean seed polysaccharides (DBSP) against anoxia/reoxygenation (A/R) injury and its potential mechanism of action in neurons. Methods: Primary cultured cerebral cortical neurons were randomly divided into four groups including control group, A/R group, DBSP + A/R group and DBSP + LY294002 + A/R group. Cell survival rate and lactate dehydrogenase (LDH) release were determined. Apoptosis, mitochondrial membrane potential and Ca2+ concentration were determined by flow cytometry analysis. The expression of T-Akt and p-Akt protein was evaluated by Western blot. Results: Compared with the control group, cell survival rate of the A/R group was decreased (P < 0.01) and LDH release, Ca2+ concentration and apoptotic rate were significantly increased (P < 0.01). Compared with the A/R group, cell survival rate of the DBSP + A/R group was increased, and LDH release, Ca2+ concentration and apoptotic rate were significantly decreased (P < 0.01), suggesting that DBSP could protect neurons against A/R injury. Mitochondrial membrane potential and the expression of p-Akt protein increased significantly in the DBSP + A/R group when compared with the A/R group (P < 0.01). The expression of p-Akt protein after treatment with LY294002 (a potent inhibitor of the PI3K-Akt signaling pathway) + DBSP + A/R was attenuated in neurons when compared with A/R + DBSP treatment (P < 0.05). Further experimental results showed that the treatment of cells with LY294002 completely blocked the expression of p-Akt protein, and significantly attenuated the protective effect of DBSP on neurons subjected to A/R. Conclusion: The protective mechanism of polysaccharides from dolichos bean seeds on neuronal cells is closely related to the PI3K-Akt signaling pathway.

Key words: dolichos bean seed polysaccharide, neuronal cells, anoxia/reoxygenation, apoptotic effect, PI3K-Akt signaling pathway