Molecular Mechanism Of Berberine's Inhibitory Effects On The Apoptosis Of NIT-1 Cells Induced By High Glucose And Saturated Fatty Acids

Part 1 Effects of Berberine on the Apoptosis of NIT-1 Cells Induced by High Glucose and Saturated Fatty AcidsObjectiveTo investigate the effects of berberine on the apoptosis of NIT-1 cells induced by high glucose and saturated fatty acids.MethodsTetrazolium (MTT) assay was applied to detect the influence of a variety of concentrations of berberine and high concentration of glucose and free fatty acids on the viability of NIT-1 cells after incubation 24 hrs. Using Annexin V / PI double labeling method the apoptosis of cultured cells was detected with the technique of flow cytometry.ResultsThe NIT-1 cells were cultured with berberine and high concentration of glucose and free fatty acids for 24 hrs. MTT showed that the inhibition of model group was significantly higher than that of normal group (P < 0.01), a variety of concentrations of berberine could reduce the cell growth inhibition by high concentration of glucose and free fatty acids (P < 0.01). Compared with normal group, it was demonstrated that the apoptotic rate of NIT-1 cells in model group was significantly elevated (P < 0.01). In comparison with model group, the apoptotic rate of NIT-1 cells in berberine group was significantly declined (P < 0.01).ConclusionIt was suggested that berberine could inhibit the apoptosis of NIT-1 cells induced by high glucose and saturated fatty acids. Part 2 Molecular Mechanism of Berberine's Inhibitory Effects on the Apoptosis of NIT-1 Cells Induced by High Glucose and Saturated Fatty AcidsObjectiveTo investigate whether berberine could inhibit the apoptosis of pancreatic isletβcells strains NIT-1 cells induced by high glucose and saturated fatty acids, and to explore its molecular mechanism.MethodsThe NIT-1 cells were cultured with berberine and high concentration of glucose and free fatty acids for 24 hrs. The cellular mRNA expression of apoptosis related genes such as Bcl-2, Bax and Caspase-3 was determined by RT-PCR, further Caspase-3 protein expression was determined by immunofluorescence assay.ResultsCompared with normal group, bcl-2 mRNA expression significantly decreased (P <0.01), while Bax and Caspase-3 mRNA expression obviously increased (P< 0.01), and cytoplasmic Caspase-3 also increased. In comparison with model group, Bcl-2 mRNA expression significantly increased (P< 0.01), while the mRNA expression of Bax and Caspase-3 evidently reduced (P< 0.01), and cytoplasmic Caspase-3 also decreased.ConclusionIt is suggested that berberine could inhibit high glucose and saturated fatty acids induced NIT-1 cell apoptosis, and berberine's anti-apoptosis effect might be possibly associated with increasing Bcl-2 expression and decreasing Bax family and Caspase-3 activation.