ABSTRACT
Objective To explore the protective effect of gallic acid in Phyllanthus emblica on high glucose－induced apoptosis of pancreatic islet β cells, and to provide a reference for the discovery of natural compounds for the treatment of diabetes. Methods In vivo experimental model, wistar male rats were used as in vivo subjects and 50 mg/kg STZ was injected intraperitoneally. After the model was successfully established, 25 mg/kg of gallic acid was given orally, and the positive drug was Sitagliptin. After 4 weeks of administration, the blood was taken and the pancreas was removed for HE staining. Western blot was used to measure the expression of NLRP3 and TXNIP in pancreatic tissue in high sugar state. In vitro model, insulinoma cell line INS－1 cells were used as in vitro targets to establish high levels. In sugar－induced apoptosis model, INS－1 cells were cultured in glucose－free RPMI 1640 complete medium supplemented with 25 mmol/L glucose. Gallic acid was used as the test sample. Experiments were divided into normal controls, high－sugar models, and low, medium and high levels of gallic acid groups. The cell viability was measured by MTT assay. The mRNA expression of NLRP3 and TXNIP in INS－1 cells was detected by QPCR and Western blot, and the expression of NLRP3 and TXNIP protein was detected.Results (1) INS－1 cells were cultured in a medium with glucose concentration of 25mmol/L for 48h, and the apoptosis rate was increased compared with the control group (P＜0.01), indicating that the apoptosis model was established successfully under high glucose conditions. (2) 10, 5, and 2.5 μmol/L GA were used to treat the control group and the high glucose model group cells respectively. The survival rate of the control group did not change significantly (P＞0.05) . Compared with the control group, the expression of NLRP3 and TXNIP in INS－1 cells in the high glucose model group was significantly different (P＜0.05);the protein expression level was significantly downregulated after GA treatment, and there was a statistical difference (P＜0.05) . Compared with the control group, the expression of NLRP3 protein in INS－1 cells in the high glucose model group was statistically different (P＜0.01), and the protein expression level was significantly downregulated after GA treatment (P＜0.01) ; The protein expression level was up－regulated (P＜0.05);the protein expression level after GA treatment was significantly down－regulated (P＜0.05); (4) The expression of NLRP3 and TXNIP mRNA in INS－1 cells was increased in the high glucose model group compared with the control group (P＜0.01) ; The expression of protein was significantly down－regulated after GA treatment (P＜0.01) . Conclusion The cells were cultured for 48 h in glucose－free RPMI 1640 complete medium supplemented with 25 mmol/L glucose. GA has no effect on the proliferation of normal INS－1 cells. GA protects INS－1 cells from apoptosis under high glucose conditions. The mechanism may be related to GA down－regulation of NLRP3 and TXNIP gene expression.
ABSTRACT
Objective To study the inhibitory effect of ursolic acid on the proliferation of human papillary thyroid carcinoma cell line TPC-1 in vitro. Method TPC-1 cells were treated with different concentrations of ursolic acid (control group:0μM, experimental group:3μM , 6μM, 12μM);MTT assay was used to observe the effect of the growth of TPC-1 cells on different concentrations of ursolic acid at the same time;Apoptosis and cell cycle distribution of TPC-1 cells were treated with ursolic acid by flow cytometry;The expression of Bcl-2, Bax and Caspase-9 mRNA in TPC-1 cells were treated with ursolic acid by QRT-PCR;The expression of Bcl-2, Bax and Caspase-9 protein in TPC-1 cells were treated with ursolic acid by Western blot. Results MTT assay showed that ursolic acid inhibited the proliferation of TPC-1 cells in a concentration and time-dependent manner, and the IC50 at 24 h, 48 h and 72 h was 14.21 μM, 10.56 μM, 10.39 μM; Flow cytometry showed that ursolic acid inhibited the apoptosis of TPC-1 cells in a concentration-dependent manner, and the growth of TPC-1 cells was arrested in S phase;QRT-PCR showed that Bcl-2, Bax and Caspase-9 mRNA were expressed in the control and experimental groups, ursolic acid inhibited the expression of Bcl-2 mRNA in a concentration-dependent manner and up-regulated the expression of Bax and Caspase-9 mRNA;Western blot results showed that Bcl-2, Bax and Caspase-9 were expressed in the control and experimental groups, ursolic acid inhibited the expression of Bcl-2 protein in a concentration-dependent manner and up-regulated the expression of Bax protein and Caspase-9 protein. Conclusion Ursolic acid can significantly inhibit the proliferation and induce apoptosis of human papillary thyroid TPC-1 cells, providing some ideas for the treatment of thyroid cancer.