AIM: This study investigated the anti-cancer effect ofcombined quercetin and a recombinant adenovirus vectorexpressing the human p53, GM-CSF and B7-1 genes(designated BB-102) on human hepatocellular carcinoma(HCC) cel...AIM: This study investigated the anti-cancer effect ofcombined quercetin and a recombinant adenovirus vectorexpressing the human p53, GM-CSF and B7-1 genes(designated BB-102) on human hepatocellular carcinoma(HCC) cell lines in vitro.METHODS: The sensitivity of HCC cells to anticancer agentswas evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of cells infectedwith BB-102 was determined by trypan blue exclusion. Theexpression levels of human wild-type p53, GM-CSF and B7-1genes were determined by Western blot, enzyme-linkedimmunosorbent assay (ELISA) and flow cytometric analysis,respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyltransferase (TdT) assay or DNA ladder electrophoresis.RESULTS: Quercetin was found to suppress proliferation ofhuman HCC cell lines BEL-7402, HUH-7 and HLE, with peaksuppression at 50 μmol/L quercetin. BB-102 infection wasalso found to significantly suppress proliferation of HCC celllines. The apoptosis of BB-102-infected HCC cells was greaterin HLE and HUH-7 cells than in BEL-7402 cells. Quercetin didnot affect the expression of the three exogenous genes inBB-102-infected HCC cells (P＞0.05), but it was found to furtherdecrease proliferation and promote apoptosis of BB-102-infected HCC cells.CONCLUSION: BB-102 and quercetin synergeticallysuppress HCC cell proliferation and induce HCC cell apoptosis,suggesting a possible use as a combined anti-cancer agent.展开更多
Supercritical antisolvent (SAS) process is a recently developed technology to produce micro- and nanoparticles. This paper presents a continuous apparatus to conduct experiment of SAS process. With the apparatus,the e...Supercritical antisolvent (SAS) process is a recently developed technology to produce micro- and nanoparticles. This paper presents a continuous apparatus to conduct experiment of SAS process. With the apparatus,the effects of pressure, temperature and flow ratio of CO2 to the solution on the shape and size of particles are studied for the quercetin-ethanol-CO2 system. Spherical quercetin microparticles with diameters ranging form i μm to 6μm can be obtained while ethanol is used as organic solvent. The most effective fact on the shape and size of particles is pressure, the next is temperature and the last is the flow ratio of CO2 to solution.展开更多
AIM: To investigate the effect of quercetin (3,3’,4’,5, 7-pentahydroxy flavone), a major flavonoid in human diet, on hyper-proliferation of gastric mucosal cells in rats treated with chronic oral ethanol. METHODS: F...AIM: To investigate the effect of quercetin (3,3’,4’,5, 7-pentahydroxy flavone), a major flavonoid in human diet, on hyper-proliferation of gastric mucosal cells in rats treated with chronic oral ethanol. METHODS: Forty male Sprague-Dawley rats, weighing 200-250 g, were randomly divided into control group (tap water ad libitum), ethanol treatment group (6 mL/L ethanol), quercetin treatment group (intragastric gavage with 100 mg/kg of quercetin per day), and ethanol plus quercetin treatment group (quercetin and 6 mL/L ethanol). Expression levels of proliferating cell nuclear antigen (PCNA) and Cyclin D1 were detected by Western blot to assay gastric mucosal cell proliferation in rats. To demonstrate the influence of quercetin on the production of extra-cellular reactive oxygen species/ nitrogen species (ROS/RNS) in rats, changes in levels of thiobarbituric acid reactive substance (TBARS), protein carbonyl, nitrite and nitrate (NOx) and nitrotyrosine (NT) were determined. The activity of inducible nitric oxide synthase (NOS) including iNOS and nNOS was also detected by Western blot. RESULTS: Compared to control animals, cell proliferationin the gastric mucosa of animals subjected to ethanol treatment for 7 days was significant increased (increased to 290% for PCNA density P < 0.05, increased to 150 for Cyclin D1 density P < 0.05 and 21.6 ± 0.8 vs 42.3 ± 0.7 for PCNA positive cells per view field), accompanied by an increase in ROS generation (1.298 ± 0.135 μmol vs 1.772 ± 0.078 μmol for TBARS P < 0.05; 4.36 ± 0.39 mmol vs 7.48 ± 0.40 mmol for carbonyl contents P < 0.05) and decrease in NO generation (11.334 ± 0.467 μmol vs 7.978 ± 0.334 μmol P < 0.01 for NOx; 8.986 ± 1.351 μmol vs 6.854 ± 0.460 μmol for nitrotyrosine P < 0.01) and nNOS activity (decreased to 43% P < 0.05). This function was abolished by the co-administration of quercetin. CONCLUSION: The antioxidant action of quercetin relies, in part, on its ability to stimulate nNOS and enhance production of NO that would interact with endogenously produced reactive oxygen to inhibit hyper-proliferation of gastric mucosal cells in rats treated with chronic oral ethanol.展开更多
Purpose:To study the inhibitive effects of quercetin (QU) on the fibroblasts proliferation of rabbit Tenon's capsule and its mechanism.Methods: Cultured fibroblasts were exposed to different concentrations of QU s...Purpose:To study the inhibitive effects of quercetin (QU) on the fibroblasts proliferation of rabbit Tenon's capsule and its mechanism.Methods: Cultured fibroblasts were exposed to different concentrations of QU solution and investigated by microculture tetrazolium (MTT) assay. The effect of QU was obser ved on cells cycle using the flow cytometer. Besults: QU can suppress the proliferation of rabbit Tenon's capsule fibroblasts in vitro and show a dose-time dependent tendency.Flow cytometer results showed 26.92% cell increase in G1 phase, 23.50% decrease in S phase and 3.42% decrease in G2 phase.Conclusions: QU can suppress the proliferation of rabbit Tenon's capsule fibroblasts in vitro and show a dose-time dependent tendency. QU may effect all phase of cell cycle and inhibit cell proliferation by inhibiting G1 phase transitting to S phase and G2 phase.展开更多
OBJECTIVE To explore the inhibitory effects of quercetin on angiogenesis of experimental mammary carcinoma. METHODS A 7,12-dimethylbenzanthracene (DMBA)-induced animal model of mammary carcinoma was established in rat...OBJECTIVE To explore the inhibitory effects of quercetin on angiogenesis of experimental mammary carcinoma. METHODS A 7,12-dimethylbenzanthracene (DMBA)-induced animal model of mammary carcinoma was established in rats. Seventy-nine female Sprague-Dawly rats were randomized into 4 groups namely, DMBA, DMBA with tamoxifen (TAM), DMBA with quercetin and control agents identified as group A, B, C and D respectively Treatment was for 28 weeks. Samples of breast tissues were collected for histopathological observation and microvessel density (MVD) estimation by light microscopy. The expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and the protein product of H-ras were examined by immunohistochemical staining. RESULTS ① The mammary carcinoma occurrence rate and mean mammary tumor diameter of group A (76.2%, 2.37cm) were significantly higher than that in group B (40.9%, 1.82cm), C (45.5%, 1.71cm) and D (0%, 0cm) (P<0.05). There was no significant difference between groups B and C (P>0.05), which indicated that quercetin inhibited the incidence and growth of mammary carcinoma; ② MVD estimation and immunohistochemical staining for VEGF, bFGF and the H-ras protein product showed significant differences between groups A and B, as well as groups A and C (P < 0.05), but no significant difference between groups B and C (P> 0.05). CONCLUSION Quercetin can reduce the DMBA- induced mammary carcinoma incidence and tumor growth.The following mechanisms may be responsibie for these results: ①Inhibition of the synthesis of the H-ras protein, causing inhibition of proliferation of the tumor cells and tumor angiogenesis. ② Inhibition of the expression of angiogenesis-related growth factors such as VEGF and bFGF, so that angiogenesis in the mammary carcinomas is suppressed, with decreased mammary MVD in the rats receiving quercetin treatment.展开更多
文摘AIM: This study investigated the anti-cancer effect ofcombined quercetin and a recombinant adenovirus vectorexpressing the human p53, GM-CSF and B7-1 genes(designated BB-102) on human hepatocellular carcinoma(HCC) cell lines in vitro.METHODS: The sensitivity of HCC cells to anticancer agentswas evaluated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The viability of cells infectedwith BB-102 was determined by trypan blue exclusion. Theexpression levels of human wild-type p53, GM-CSF and B7-1genes were determined by Western blot, enzyme-linkedimmunosorbent assay (ELISA) and flow cytometric analysis,respectively. The apoptosis of BB-102-infected or quercetin-treated HCC cells was detected by terminal deoxynucleotidyltransferase (TdT) assay or DNA ladder electrophoresis.RESULTS: Quercetin was found to suppress proliferation ofhuman HCC cell lines BEL-7402, HUH-7 and HLE, with peaksuppression at 50 μmol/L quercetin. BB-102 infection wasalso found to significantly suppress proliferation of HCC celllines. The apoptosis of BB-102-infected HCC cells was greaterin HLE and HUH-7 cells than in BEL-7402 cells. Quercetin didnot affect the expression of the three exogenous genes inBB-102-infected HCC cells (P＞0.05), but it was found to furtherdecrease proliferation and promote apoptosis of BB-102-infected HCC cells.CONCLUSION: BB-102 and quercetin synergeticallysuppress HCC cell proliferation and induce HCC cell apoptosis,suggesting a possible use as a combined anti-cancer agent.
文摘Supercritical antisolvent (SAS) process is a recently developed technology to produce micro- and nanoparticles. This paper presents a continuous apparatus to conduct experiment of SAS process. With the apparatus,the effects of pressure, temperature and flow ratio of CO2 to the solution on the shape and size of particles are studied for the quercetin-ethanol-CO2 system. Spherical quercetin microparticles with diameters ranging form i μm to 6μm can be obtained while ethanol is used as organic solvent. The most effective fact on the shape and size of particles is pressure, the next is temperature and the last is the flow ratio of CO2 to solution.
基金State Education Ministry Scientific Research Foundation for the Returned Overseas Chinese Scholars, No. 1999747
文摘AIM: To investigate the effect of quercetin (3,3’,4’,5, 7-pentahydroxy flavone), a major flavonoid in human diet, on hyper-proliferation of gastric mucosal cells in rats treated with chronic oral ethanol. METHODS: Forty male Sprague-Dawley rats, weighing 200-250 g, were randomly divided into control group (tap water ad libitum), ethanol treatment group (6 mL/L ethanol), quercetin treatment group (intragastric gavage with 100 mg/kg of quercetin per day), and ethanol plus quercetin treatment group (quercetin and 6 mL/L ethanol). Expression levels of proliferating cell nuclear antigen (PCNA) and Cyclin D1 were detected by Western blot to assay gastric mucosal cell proliferation in rats. To demonstrate the influence of quercetin on the production of extra-cellular reactive oxygen species/ nitrogen species (ROS/RNS) in rats, changes in levels of thiobarbituric acid reactive substance (TBARS), protein carbonyl, nitrite and nitrate (NOx) and nitrotyrosine (NT) were determined. The activity of inducible nitric oxide synthase (NOS) including iNOS and nNOS was also detected by Western blot. RESULTS: Compared to control animals, cell proliferationin the gastric mucosa of animals subjected to ethanol treatment for 7 days was significant increased (increased to 290% for PCNA density P < 0.05, increased to 150 for Cyclin D1 density P < 0.05 and 21.6 ± 0.8 vs 42.3 ± 0.7 for PCNA positive cells per view field), accompanied by an increase in ROS generation (1.298 ± 0.135 μmol vs 1.772 ± 0.078 μmol for TBARS P < 0.05; 4.36 ± 0.39 mmol vs 7.48 ± 0.40 mmol for carbonyl contents P < 0.05) and decrease in NO generation (11.334 ± 0.467 μmol vs 7.978 ± 0.334 μmol P < 0.01 for NOx; 8.986 ± 1.351 μmol vs 6.854 ± 0.460 μmol for nitrotyrosine P < 0.01) and nNOS activity (decreased to 43% P < 0.05). This function was abolished by the co-administration of quercetin. CONCLUSION: The antioxidant action of quercetin relies, in part, on its ability to stimulate nNOS and enhance production of NO that would interact with endogenously produced reactive oxygen to inhibit hyper-proliferation of gastric mucosal cells in rats treated with chronic oral ethanol.
文摘Purpose:To study the inhibitive effects of quercetin (QU) on the fibroblasts proliferation of rabbit Tenon's capsule and its mechanism.Methods: Cultured fibroblasts were exposed to different concentrations of QU solution and investigated by microculture tetrazolium (MTT) assay. The effect of QU was obser ved on cells cycle using the flow cytometer. Besults: QU can suppress the proliferation of rabbit Tenon's capsule fibroblasts in vitro and show a dose-time dependent tendency.Flow cytometer results showed 26.92% cell increase in G1 phase, 23.50% decrease in S phase and 3.42% decrease in G2 phase.Conclusions: QU can suppress the proliferation of rabbit Tenon's capsule fibroblasts in vitro and show a dose-time dependent tendency. QU may effect all phase of cell cycle and inhibit cell proliferation by inhibiting G1 phase transitting to S phase and G2 phase.
文摘OBJECTIVE To explore the inhibitory effects of quercetin on angiogenesis of experimental mammary carcinoma. METHODS A 7,12-dimethylbenzanthracene (DMBA)-induced animal model of mammary carcinoma was established in rats. Seventy-nine female Sprague-Dawly rats were randomized into 4 groups namely, DMBA, DMBA with tamoxifen (TAM), DMBA with quercetin and control agents identified as group A, B, C and D respectively Treatment was for 28 weeks. Samples of breast tissues were collected for histopathological observation and microvessel density (MVD) estimation by light microscopy. The expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and the protein product of H-ras were examined by immunohistochemical staining. RESULTS ① The mammary carcinoma occurrence rate and mean mammary tumor diameter of group A (76.2%, 2.37cm) were significantly higher than that in group B (40.9%, 1.82cm), C (45.5%, 1.71cm) and D (0%, 0cm) (P<0.05). There was no significant difference between groups B and C (P>0.05), which indicated that quercetin inhibited the incidence and growth of mammary carcinoma; ② MVD estimation and immunohistochemical staining for VEGF, bFGF and the H-ras protein product showed significant differences between groups A and B, as well as groups A and C (P < 0.05), but no significant difference between groups B and C (P> 0.05). CONCLUSION Quercetin can reduce the DMBA- induced mammary carcinoma incidence and tumor growth.The following mechanisms may be responsibie for these results: ①Inhibition of the synthesis of the H-ras protein, causing inhibition of proliferation of the tumor cells and tumor angiogenesis. ② Inhibition of the expression of angiogenesis-related growth factors such as VEGF and bFGF, so that angiogenesis in the mammary carcinomas is suppressed, with decreased mammary MVD in the rats receiving quercetin treatment.
