Effect of Lycium bararum polysaccharides on methylmercury-induced abnormal differentiation of hippocampal stem cells

The aim of the present study was to observe the effects of a general extract of Lycium bararum polysaccharides (LBPs) on methylmercury (MeHg)-induced damage in hippocampus neural stem cells (hNSCs). The hippocampal tissues of embryonic day 16 Sprague-Dawley rats were extracted for the isolation, purification and cloning of hNSCs. Following passage and proliferation for 10 days, the cells were allocated at random into the following groups: Control, LBPs, MeHg and MeHg + LBPs. MTT and microtubule-associated protein 2 (MAP-2)/glial fibrillary acidic protein/Hoechst immunofluorescence tests were performed to detect the differentiation and growth of hNSCs in the various groups. The differentiation rate of MeHg-treated hNSCs and the perimeter of MAP-2-positive neurons were 3.632 +/- 0.63% and 62.36 +/- 5.58 mu m, respectively, significantly lower compared with the control group values of 6.500 +/- 0.81% and 166 +/- 8.16 mu m (P < 0.05). Furthermore, the differentiation rate and the perimeter of MAP-2-positive neurons in LBPs groups cells was 7.75 +/- 0.59% and 253.3 +/- 11.21 mu m, respectively, significantly higher compared with the control group (P < 0.05). The same parameters in the MeHg + LBPs group were 5.92 +/- 0.98% and 111.9 +/- 6.07 mu m, respectively, significantly higher than the MeHg group (P < 0.05). The astrocyte differentiation rates in the MeHg and MeHg + LBPs group were 41.19 +/- 2.14 and 34.58 +/- 1.70, respectively (P < 0.05). These results suggest that LBPs may promote the generation and development of new neurons and inhibit the MeHg-induced abnormal differentiation of astrocytes. Thus, LBPs may be considered to be a potential new treatment for MeHg-induced neurotoxicity in hNSCs.