Effects of Bushen Tongmai Recipe on protein kinase Balpha expression in polycystic ovary rats with insulin resistance / 中国结合医学杂志

<p><b>OBJECTIVE</b>To observe the effects of Bushen Tongmai Recipe (, BSTMR) on mRNA and protein expressions of protein kinase B alpha (PKB alpha) in hepatic, adipose, muscular, and ovarian tissues of polycystic ovary (PCO) rats with insulin resistance (IR) and to explore the possible molecular mechanism of BSTMR in treating IR and ovulation dysfunction.</p><p><b>METHODS</b>Female 22-day-old SD rats were injected subcutaneously with sodium prasterone sulfate (9 mg.100g(-1).d(-1)) for 20 days and fed with high-fat diet for 80 days to induce PCO rats with IR. Then, the PCO rats were randomly divided into the model group (n=23) and the treated group (n=21). The treated group was administered with BSTMR for 2 weeks. Meanwhile, a group with 15 rats of the same age was used as the control group. The histological changes in the ovaries were examined. Fasting blood glucose (FBG) was determined by the glucose oxidase method. Serum fasting insulin (Fins) was determined by radioimmunoassay (RIA). The mRNA level of PKBalpha was measured by reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemistry staining and Western blot analysis were employed to detect the protein expression in target tissues.</p><p><b>RESULTS</b>Compared with the control group, the ovaries in the model group showed multiple follicular cysts, levels of FBG and Fins in the model group increased markedly (P<0.05 or P<0.01, respectively), and the insulin sensitive index (ISI) decreased obviously (P<0.01). The mRNA and protein expressions of PKBalpha in target tissues in the model group were dramatically lower than those in the control group (P<0.05 or P<0.01). Compared with the model group, the stratum granulosum of the ovarian follicle in the treated group increased markedly, the level of Fins in the treated group decreased obviously (P<0.01), ISI in the treated group improved markedly (P<0.01), and the mRNA and protein expressions of PKBalpha in target tissues of the treated rats were elevated significantly (P<0.05 or P<0.01).</p><p><b>CONCLUSION</b>BSTMR could improve IR and ovulation dysfunction in PCO rats with IR, and its molecular mechanisms might be closely related with the elevation of mRNA and protein expressions of PKBalpha in target tissues of PCO rats with IR.</p>

8-hydroxy-dihydroberberine ameliorated insulin resistance induced by high FFA and high glucose in 3T3-L1 adipocytes / 药学学报

The purpose of the study is to investigate the effect of 8-hydroxy-dihydroberberine on insulin resistance induced by high free fatty acid (FFA) and high glucose in 3T3-L1 adipocytes and its possible molecular mechanism. Palmic acid or glucose in combination with insulin was used to induce insulin resistance in 3T3-L1 adipocytes. 8-Hydroxy-dihydroberberine and berberine were added to the cultured medium separately, which were considered as treated group and positive control group. The rate of glucose uptake was determined by 2-deoxy-[3H]-D-glucose method. The amount of glucose consumption in the medium was measured by glucose oxidase method. Cell growth and proliferation of 3T3-L1 adipocytes were detected with Cell Counting Kit-8 (CCK-8) assay. After incubated with palmic acid for 24 hours or glucose with insulin for 18 hours, the rate of glucose transport in 3T3-L1 adipocytes was inhibited by 67% and 58%, respectively. The amount of glucose consumption in 3T3-L1 adipose cells was decreased by 41% after cells were incubated with palmic acid for 24 h. However, the above changes were reversed by pretreatment with 8-hydroxy-dihydroberberine for 24 and 48 h. Significant difference existed between groups. Insulin resistance in 3T3-L1 adipocytes, which is induced by high FFA and high glucose, could be ameliorated by 8-hydroxy-dihydroberberine.

Effect of berberine on insulin secretion and glucokinase activity of NIT-1 cells / 药学学报

To investigate the effect of berberine on insulin secretion of NIT-1 cells stimulated by glucose and the possible molecular mechanism, we used radioimmunoassay, scintillation counting technique, enzymatic method and Western blotting to measure the effects of berberine on insulin secretion, glucose utilization, the activity of glucokinase (GK) and protein level of GK and GK regulation protein (GKRP). Compared with untreated group, insulin secretion level, glucose utilization, the activity and protein level of GK in NIT-1 cells stimulated by high concentration of glucose were increased significantly in berberine group (P < 0.05), while the protein level of GKRP in berberine group decreased markedly. In conclusion, berberine can promote insulin secretion of NIT-1 cells induced by high concentration of glucose. The possible molecular mechanism may be associated with berberine acting as a GK activator, improving glucose utilization, enhancing the activity and protein expression level of GK, as well as decreased the protein level of GKRP.