Yeast β-glucan with different degrees of oxidation: Capability of adsorbing lead ions and protective effect against lead-induced PC12 cytotoxicity.

This study investigated the adsorption behavior of Pb by three different oxidized yeast β-glucans (OYG) and their effect on lead-induced PC12 cytotoxicity. The analysis revealed that the adsorption kinetics conformed to pseudo-first-order model and the adsorption capacities for Pb (36.50, 41.61 and 50.31 μg/mg for OYG1-3) showed a positive correlation with oxidation degree (15.2%, 47.3% and 71.2% for OYG1-3). Additionally, the lead adsorption by OYGs showed an endothermic process and the adsorption capacity increased with the increasing Pb concentration in the aqueous phase. Then, it was found that OYGs were biocompatible and could increase cell viability from 60% to 80% during lead stress. Nuclear staining revealed an inhibitory effect of OYGs on cell apoptosis, with the best performance for OYG3. Furthermore, OYGs could significantly suppress lead-induced production of reactive oxygen species (ROS) and nitric oxide (NO) in PC12 cells. Specifically, when being supplemented with 20 μg/mL OYG3, the increase of fluorescence intensity caused by the production of ROS and NO in PC12 cells were significantly alleviated from 2.65 and 2.6 to 1.23 and 1.35-fold, respectively. Our findings indicate that OYGs could adsorb lead effectively and protect PC12 cells from lead-induced cytotoxicity.