Effects Of Loganin And Paeoniflorin On The Proliferation And The Relative Expression Of NGF And IGF-1in Rat Schwan Cells Which Cultured In High Glucose

Objective:To investigate the influence of loganin and paeoniflorin on proliferation and expression of NGF、IGF-1of rat Schwan cells cultured in high glucose, so as to explore the possible mechanism of loganin and paeoniflorin in the treatment of diabetic peripheral neuropathy. Methods: Schwan cells were cultured in vitro, and were divided the control group, high glucose group(50mMGlu), loganin group (5μg·mL-1,10μg·mL-1,20μg·mL-1,,40μg·L-1), paeoniflorin group(3μg·mL-1,6μg·mL-1,12μg·mL-1,24μg·mL-1). With different concentrations of loganin and paeoniflorin affect Schwan cells cultured in high glucose after48h, then observe the effect of loganin and paeoniflorin on proliferation of Schwann cells in different concentrations by four methyl thiazolyl tetrazolium (MTT), and measure the expression of NGF and IGF-1mRNA in Schwann cells by reverse transcription polymerase chain reaction (RT-PCR), and detect the expression of NGF and IGF-1protein in Schwann cells by immunocyto chemistry. Results:Observed from the experiment of MTT, high glucose can inhibit the proliferation of Schwann cells (compared with the control group, P<0.05), loganin (10μg·mL-1,20μg·mL-1,40μg·mL-1) and paeoniflorin (6μg·mL-1,11μg·mL-1,24μg·mL-1) promote high glucose cultured Schwann cell proliferation in varying degrees, counteract the proliferation inhibition effect of high glucose. Observed from the experiment of RT-PCR, the expression of NGF and IGF-1mRNA in high glucose group was lower than that in the control group, and there is a significant difference (P<0.05);Compared with high glucose group, the expression of NGF mRNA in loganin (5μg·mL-1,10μg·mL-1,20μg·mL-1,40μg·mL-1) increased in varying degrees, and there is a significant difference(P<0.05) in loganin20μg·mL-1group; Compared with high glucose group, the expression of IGF-1mRNA in loganin (20μg·mL-1,40μg·mL-1) increased in varying degrees (P<0.05), while the expression of IGF-1mRNA in loganin (5μg·mL-1,10μg·mL-1)were not statistically significant difference(P>0.05); Compared with high glucose group, the expression of NGF, IGF-1mRNA in paeoniflorin (6μg·L-1,12μg·L-1,24μg·L-1) increased in varying degrees, and there is a significant difference (P<0.05) in12μg·mL-1group, while3ug/ml of paeoniflorin NGF, IGF-1mRNA was not statistically significant difference(P>0.05).Observed from the cell immunity in the chemical experiment, in the control group the positive expression of NGF and IGF-1was mainly expressed in the cytoplasm. The positive expression of NGF and IGF-1in high glucose groups was significantly lower than that in the control group. Compared with high glucose group, the positive expression of NGF and IGF-1in loganin (5μg·mL-1,10μg·mL-1,20μg·mL-1,40μg·mL-1) increased in varying degrees, in which 20μg·mL-1,40μg·mL-1is most obvious. Compared with high glucose group, the positive expression of NGF and IGF-1in paeoniflorin (12μg·mL-1,24μg·mL-1)increased(P<0.05), while the positive expression of NGF and IGF-1in paeoniflorin (3μg·mL-1,6μg·mL-1) were not statistically significant difference(P>0.05). Conclusion:1,High glucose can inhibit the proliferation of Schwann cells, and with the more increase of glucose concentration, the inhibition was the more obviously.2, High glucose can cause the expression of NGF and IGF-1gene and protein down regulation in Schwann cells,and can decrease the secreting of NGF and IGF-1significantly in Schwann cells.3, Loganin and Paeoniflorin can promote the proliferation of Schwann cells cultured with high glucose and up-regulation the expression of NGF and IGF-1gene and protein, and increase the secreting of NGF and IGF-1, so as to protect and improve the morphology and function of peripheral nerve and promote the repair of nerve injury, which is the possible mechanism in the treatment of diabetic peripheral neuropathy.