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

Abstract

This study investigated the adsorption behavior of Pb2+ 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 Pb2+ (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 Pb2+ 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.