Effects of lycium barbarum polysaccharide on MIN6 cells viability and apoptosis

Objective To study the effects of different concentration lycium barbarum polysaccharide (LBP) on mouse islet β cell line MIN6 cells viability and apoptosis.Methods MIN6 cells were cultured and divided into control group and different concentration LBP intervene group,treated separately with 0,100,200,400 mg/L LBP for 24 h.Cells viability and apoptosis were separately detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry.The expression of phosphorylated extracellular regulated protein kinase (ERK) and B-cell lymphoma 2 (Bcl-2) were analyzed by Western blot.Results Compared with control group,MIN6 cells viability was promoted (all P ＜ 0.01),apoptosis was repressed (all P ＜0.01) in 100,200 mg/L LBP intervene group,while MIN6 cells viability was decreased (P ＜ 0.05) and apoptosis was increased (P ＜ 0.05) in 400 mg/L LBP intervene group.Compared with control group,protein levels of Bcl-2 and phosphorylated ERK were increased in 100,200,400 mg/L LBP intervene group (F =65.26,P ＜0.01 ; F =14.85,P ＜0.01),and decreased in 400 mg/L LBP intervene group.The difference of levels of Bcl-2 and phosphorylated ERK were statistically significant between 200 mg/L LBP intervene group and 400 mg/L LBP intervene group (all P ＜ 0.01).Conclusions Lower concentration LBP could promote the proliferation and inhibit the apoptosis of MIN6 cells,while the effects of higher concentration LBP were on the contrary.The mechanisms were associated with ERK signaling pathway. Key words: Lycium barbarum polysaccharide;  MIN6 cells ;  Cells viability ;  Apoptosis