Background and purpose:Brucine is one of the active components from Strychnos nux vomica,with signifi cant analgesic,anti-inflammatory and platelet-aggregating inhibitory properties.Due to its cytotoxic effect,the anti-tumor effect of brucine has increasingly been appreciated.In this study,we investigated the impact of brucine on A549 cells proliferation,apoptosis as well as the underlying mechanisms.Methods:MTT assay was used to examine the cell viability,flow cytometric analysis and fluorescent microscope were applied to examine cell apoptosis,ELISA method was used to examine the effect of brucine on PGE2 release from A549 cells and RT-PCR analysis was used to measure mRNA content,western blotting analysis was used to measure protein expression and luciferase activity was detected to examine the effect of brucine on COX-2 promoter activity.Results:Brucine was able to suppress the proliferation of A549 cells and induce cell apoptosis to time-dependent and dose-dependent manner.To understand the mechanisms,COX-2 was identifi ed to be an important target molecule involved in the apoptosis induced by brucine because brucine could suppress the COX-2 mRNA,protein expressions as well as PGE2 release in A549 cells in a timedependent manner.Furthermore,overexpression of COX-2 abrogated brucine-induced cell apoptosis,in contrast,when A549 cells were transfected with COX-2 siRNA,the apoptotic effect of brucine was dramatically enhanced.Further analysis revealed that brucine was able to suppress COX-2 transcriptional activation.Conclusion:Brucine was able to induce lung cancer apoptosis via downregulation of COX-2.

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OBJECTIVETo study the molecular mechanism of cyclooxygenase-2 (COX-2), one of effective ingredient of brucine, in inducing non-small cell lung cancer cell apoptosis.

METHODCOX-2 promoter, transcription factor deletion mutants and COX-2 mRNA 3'-UTR-containing report plasmids were transfected with Renillia to non-small cell lung cancer A549 cell, in order to detect the activity of report gene luciferase and minimum cis-acting element of COX-2 promoter inhibited by brucine. The influence of brucine on IkappaB phosphorylation and the nuclear translocation of p65 were detected by immunoblotting assay.

RESULTBrucine significantly suppressed LPS-induced COX-2 promoter activation, but revealed minor impact on COX-2 mRNA stability. NF-kappaB in the vicinity of COX-2 promoter-262 was an important cis-acting element of brucine for inhibiting the activity of COX-2 promoter. Brucine was found to inhibit the phosphorylation of IkappaBalpha as well as the nuclear translocation of p65.

CONCLUSIONBrucine can improve A549 cells apoptosis by inhibiting the activity of NF-kappaB and the subsequent COX-2 gene expression.

Biological Transport ; drug effects ; Carcinoma, Non-Small-Cell Lung ; genetics ; metabolism ; Cell Line, Tumor ; Cyclooxygenase 2 ; genetics ; Humans ; NF-kappa B ; metabolism ; Phosphorylation ; drug effects ; Promoter Regions, Genetic ; drug effects ; genetics ; RNA Stability ; drug effects ; Strychnine ; analogs & derivatives ; pharmacology

AIM: To study preparation of strychnine solid liposome. METHODS: Sorbitol carrier aggradation method and freeze drying method were used to prepare strychnine solid liposomes. They were evaluated by particle morphology, the size range, resolvable peculiarity in the water, encapsulation efficiency. RESULTS: The particles of liposome by sorbitol carrier aggradation method were less than that by freeze drying method, and its encapsulation efficiency was higher than that by freeze drying method. CONCLUSION: Sorbitol carrier aggradation method is better than freeze drying method.

Aim To evaluate the effects of Brucine of restraining transplanted tumor growth,prolonging their survival time and its toxicity on haematopoietic and immune systems as well as hepatic and renal function in mice transplanted with Hepatocarcinoma Heps cells.Methods ICR male mice of Hepatocarcinoma Heps tumor model(Heps mice)was made through Heps cells inoculation.Anti-tumor activity of Brucine was evaluated in terms of tumor inhibitory ratio and life elongational ratio of mice transplanted with Heps tumor.The toxicity of Brucine was measured the mice weight,immune organ weight,blood cell index(leukocyte,erythrocyte,platelet,and hemachrome protein),and hepatic function index(ALT,AST)as well as renal function index(BUN) of Heps mice.Results Brucine had significant restraining effect on the growth of Heps tumor in mice.Its inhibitory rate was 30.34%(1.61 mg?kg~(-1)),46.21%(3.23 mg?kg~(-1))and 42.07%(6.46 mg?kg~(-1))respectively,and 3.23 mg?kg~(-1)(1/20 LD_(50)) was the best dosage of Brucine for treating Heps tumor in vivo,while Brucine had no distinct effect of prolonging the life of Heps mice.Moreover,it enhanced the weight of body and thymus index as well as spleen index,and had no distinct influence on blood cell index as well as ALT,AST and BUN in Heps mice.Conclusion Brucine can inhibit the growth of transplanted Heps tumor,enhance the weight of immune organ index significantly,and has no toxicity on haematopoietic and immune systems as well as hepatic and renal function of mice transplanted with Heps tumor.It may be developed into a promising anticancer drug through further study