Determination of Entrapment Efficiency of Buthionine Sulfoximine Nanoparticles in Different Entrapping Systems by HPLC / 中国药师

Objective:To establish an HPLC method to determine the entrapment efficiency of buthionine sulfoximine (BSO) nan-oparticles in different entrapping systems .Methods:Free BSO was separated from the loaded nanoparticles by high speed centrifugation in two entrapping systems and the entrapment efficiency of buthionine sulfoximine nanoparticles was determined by HPLC .A WondaSil C18 column (250 mm ×4.6 mm, 5 μm) was used and the mobile phase was methanol-water (20 ∶80).The flow rate was 0.4 ml· min-1 and the column temperature was 30℃.The detection wavelength was set at 210 nm and the volume of injection was 20 μl.Re-sults:BSO had a good linear relationship within the range of 2.0-320.0μg· ml-1(r=0.999 7).The average recovery was 101.05%and RSD was 0.74%(n=9).The average entrapment efficiency of HP/CaCO3/CaHPO4/BSO nanoparticles and HP/PS/CaCO3/BSO hydrid nanovesicles was 25.63% and 58.62%, respectively.Conclusion:The method has good repeatability and high accuracy and sensitivity, which is applicable to determine the entrapment efficiency of BSO nanoparticles .HP/PS/CaCO3/BSO hydrid nanovesicles entrapped system is superior to HP/CaCO3/CaHPO4/BSO nanoparticles entrapped system .

Study on in vitro reversing multidrug resistance of human breast cancer cells by buthionine sulfoximine / 中国药学杂志

OBJECTIVE: To study the effect of BSO administration on the multidrug resistance (MDR) transformation of human breast cancer cell line in vitro. METHODS: The intracellular GSH content was measured by glutathione reductase recycling assay; the 50% inhibitory concentration (IC50) of ADM was measured by MTT assay, then the multidrug resistance property and multidrug resistance reversal times were determined; the apoptosis rate and cell cycle of MCF-7/ADM cell both before and after BSO administration were measured by flow cytometry. RESULTS: The level of GSH in MCF-7/ADM cells was significantly higher than that in MCF-7 cells; the BSO treatment exerted significant inhibitory effect on the synthesis of GSH in MCF-7/ADM while slight effect on MCF-7 cell; The IC50 of ADM in MCF-7/ADM cells was decreased by BSO of certain doses, the multidrug resistance reversal times by BSO at concentrations of 50, 100, 200, 400, and 800 μmol · L-1 were 1.25, 2.02, 8.42, 12.65, and 9.71 respectively, but BSO had no such effect on MCF-7 cell. The value of apoptosis rate and the cells accumulated in Go/GI phase increased significantly when BSO and ADM were simultaneously used compared with using ADM merely. CONCLUSION: BSO can potentially reverse the MDR of MCF-7/ADM cells by inhibition of GSH synthesis in vitro, and the effect may be achieved by inducing apoptotic cell death. Copyright 2012 by the Chinese Pharmaceutical Association.

Study of the rdiosensitivity of DL-BSO on rats C_6 glioma cells / 中国药理学通报

Aim To observe the effect of DL-buthionine s ulfoximine(DL-BSO) on the radiosensitivity of rat C 6 glioma cells under the a erobic and the hypoxic condition. Methods The source of radiati on was 60Co ?-rays. The rats C 6 glioma cells were treated by radia tion alone or DL-BSO+radiation under the aerobic and the hypoxic condition. Col ony forming assay was used to measure effects of DL-BSO on the radiosensitivity . Results Radiosensitive effect of DL-BSO was time-depedent u nder the aerobic condition. After treatment with 0.1 mmol?L -1 DL-BSO fo r 2, 6, 12 hours, the radiosensitive effect was not observed, whereas an enhance ment of radiosensitivity was seen at 24 and 48 hours. An enhancement of radiosen sitivity was seen at 2～48 hours after treatment with 0.1 mmol?L -1 DL-B SO under the hypoxic condition. The radiosensitive effects related to DL-BSO co ncentration under the aerobic and the hypoxic condition. Conclusion Both under the aerobic and the hypoxic conditions DL-BSO can increase the radio sensitivity of rat C 6 glioma cells. DL-BSO increased the rat C 6 gliom a cells radiosensitivity especially under the hypoxic condition, and radiosensit ive effect of DL-BSO is time and concentration-dependent.

Effects of cyclophosphamide on pharmacokinetics of buthionine sulfoximine in Walker-256 tumor-bearing rats / 中国药理学通报

AIM: To study the effects of cyclophosphamide (CTX) on the pharmacokinetics of buthionine sulfoximine (BSO) in Walker-256 tumor-bearing rats. METHODS: Walker-256 tumor-bearing rats were treated ip for 4 days with saline or CTX in saline (20 mg·kg-1), then received iv BSO 200mg·kg-1. BSO concentration in rat plasma was determined by a reverse phase HPLC with fluorescence detection after precolumn derivatization with o-phthaldialdehyde. Compartment model and pharmacokinetic parameters were determined by 3P87 software processed on a computer. RESULTS: A single intravenous dose of BSO 200 mg·kg-1 was eliminated from plasma in a two-compartment manner in tumor-bearing rats. The pharmacokinetic parameters of BSO were as follows: In tumor-bearing control rats, T1/2α = (11.1±2.4) min, T1/2β = (65±14) min, CLs= (12.8±1.3) ml·min-1·kg-1, AUC= (262±26) mg · L-1 ·h; in tumor-bearing CTX-treated rats, T1/2α=(8.2±1.8) min, T1/2β=(42±3)min, CLs = (13.4±1.9) ml·min-1·kg-1, AUC= (252±35) mg ·L-1·h. CONCLUSION: There is no significant difference between the parameters of tumor-bearing control and CTX-treated rats except T1/2β.

Effect of Glutathione on Lead Induced Modulation of NO Synthesis in RAW 264.7 Cell / 예방의학회지

OBJECTIVES: To evaluate the effect of glutathione(GSH) on lead induced modulation of nitric oxide(NO) synthesis, and to examine how lead modulates NO production in macrophages. METHODS: This study was observed in a culture of RAW 264.7 cells, which originated from a tumor in a Balb/c mouse that was induced by the Abelson murine leukemia virus. The compounds investigated were lead chloride, N-acetyl-cystein(NAC), and Buthionine Sulfoximine(BSO). RESUJLTS: ATP synthesis in RAW 264.7 cells was unchanged by each lead concentration exposure in a dose dependent manner. The NO synthesis was decreased when exposed to lead(PbCl2) concentration 0.5 micro M. The presence of 300 micro M NAC, used as a pretreatment in the culture medium, caused the recovery of the lead induced decrease in NO synthesis, but in the presence of 300 micro M BSO as a pretreatment, there was no recoverey. Pretreatment with NAC and BSO had no affect on ATP synthesis at any of the lead concentrations used. CONCLUSIONS: These results indicated that GSH has a protective effect toward lead toxicity, and suggested that the inhibition of NO production in macrophage due to lead toxicity may be related to cofactors of iNOS (inducible nitric oxide synthase)

Effect of Glutathione on Lead Induced Modulation of NO Synthesis in RAW 264.7 Cell / 예방의학회지

OBJECTIVES: To evaluate the effect of glutathione(GSH) on lead induced modulation of nitric oxide(NO) synthesis, and to examine how lead modulates NO production in macrophages. METHODS: This study was observed in a culture of RAW 264.7 cells, which originated from a tumor in a Balb/c mouse that was induced by the Abelson murine leukemia virus. The compounds investigated were lead chloride, N-acetyl-cystein(NAC), and Buthionine Sulfoximine(BSO). RESUJLTS: ATP synthesis in RAW 264.7 cells was unchanged by each lead concentration exposure in a dose dependent manner. The NO synthesis was decreased when exposed to lead(PbCl2) concentration 0.5 micro M. The presence of 300 micro M NAC, used as a pretreatment in the culture medium, caused the recovery of the lead induced decrease in NO synthesis, but in the presence of 300 micro M BSO as a pretreatment, there was no recoverey. Pretreatment with NAC and BSO had no affect on ATP synthesis at any of the lead concentrations used. CONCLUSIONS: These results indicated that GSH has a protective effect toward lead toxicity, and suggested that the inhibition of NO production in macrophage due to lead toxicity may be related to cofactors of iNOS (inducible nitric oxide synthase)

Enhancement of Cytotoxicity of Chemotherapeutic Agents by Buthionine sulfoximine in Retinoblastoma Cell Line

This study was performed to evaluate in vitro cytotoxicity of chemotherapeutic agents in established human retinoblastoma cell line, Y79 and to study the possibility of enhancing the cytotoxicity of chemotherapeutic agents by administration of buthionine sulfoximine(BSO) which lowers the intracellular glutathione(GSH) level. IC50 defined as the concentration which inhibits the cell survival rates to 50% compared with control group was used to evaluate cytotoxicity. Intracellular level after 13.50 adminstration were measured and compared with the level prior to administration of BSO. Doxorubicin, cisplatin, and melphalan showed significant decrease of IC50 by administration of BSO(p0.05). Intracellular GSH level prior to the administration of BSO was 0.931nM/mg protein. After the administration of BSO, they were lowered to 0.095nM/mg protein in both BSO concentrations. Results listed above suggest that cytotoxicity of doxorubicin, cisplatin, and melphalan can be enhanced by ESO. This effect may be mediated by decreased intracellualr level of GSH by BSO.

Enhanced Therapeutic Effects of Carboplatin by Buthionine Sulfoximine in MBT-2 Bladder Tumor / 대한비뇨기과학회지

Glutathione based detoxification system in tumor cells was proposed as one of the drug resistance mechanisms and appeared to play as an obstacle in anticancer chemotherapy. It was evaluated that depletion of glutathione content in MBT-2, murine bladder tumor cells by buthionine sulfoximine could enhance the chemotherapeutic effect of carboplatin. Glutathione contents were measured by an enzymatic assay and chemosensitivity was assessed by MTT colorimetric test. Twenty-four hours exposure to 1, 2.5, 5 and 10uM buthionine sulfoximine reduced intracellular glutathione levels to 84.9, 24.8, 18.3 and 11.0% of the control level, respectively, in MBT-2 tumor cell line. Pretreatment with 2.5, 5 and 10uM buthionine sulfoximine for 24 hours and continuous exposure to buthionine sulfoximine and carboplatin for 72 hours potentiated the carboplatin cytotoxicity by 1.26, 1.56 and 1.90 folds, respectively. The potentiation of antitumor effect of carboplatin in C3H/He mice MBT-2 tumor by buthionine sulfoximine was evaluated with the use of tumor growth and tumor volume-doubling time. Glutathione contents in the tumor and liver were reduced to 12.8 and 21.8% of the control level by oral administration of 30mM buthionine sulfoximine for 5 days. No significant change in serum creatinine levels and renal histology was found in the mice treated with buthionine sulfoximine. Combination of carboplatin and buthionine sulfoximine significantly reduced tumor growth rate and delayed tumor volume-doubling time compared to carboplatin alone(p 0.05). Weight loss or mortality due to carboplatin and buthionine sulfoximine administration was not noted. Since buthionine sulfoximine significantly enhanced the effect of carboplatin on murine bladder tumor without apparent toxicity, combination of buthionine sulfoximine and carboplatin could be a new strategy in chemotherapy against advanced bladder cancer.

Effects of cyclophosphamide on pharmacokinetics of buthionine sulfoximine in Walker-256 tumor-bearing rats / 中国药理学通报

AIM To study the effects of cyclophosphamide (CTX) on the pharmacokinetics of buthionine sulfoximine (BSO)in Walker 256 tumor bearing rats. METHODS Walker 256 tumor bearing rats were treated ip for 4 days with saline or CTX in saline (20 mg?kg -1 ), then received iv BSO 200 mg?kg -1 . BSO concentration in rat plasma was determined by a reverse phase HPLC with fluorescence detection after precolumn derivatization with o phthaldialdehyde. Compartment model and pharmacokinetic parameters were determined by 3P87 software processed on a computer. RESULTS A single intravenous dose of BSO 200 mg?kg -1 was eliminated from plasma in a two compartment manner in tumor bearing rats. The pharmacokinetic parameters of BSO were as follows: In tumor bearing control rats, T 1/2? =(11 1?2 4) min, T 1/2? =(65?14) min, CLs=(12 8?1 3) ml?min -1 ?kg -1 , AUC=(262?26) mg?L -1 ?h; in tumor bearing CTX treated rats, T 1/2? =(8 2?1 8) min, T 1/2? =(42?3) min, CLs=(13 4?1 9) ml?min -1 ?kg -1 ,AUC=(252?35) mg ?L -1 ?h. CONCLUSION There is no significant difference between the parameters of tumor bearing control and CTX treated rats except T 1/2? .