【Abstract】Objective To investigate the inhibitory effects of flavonoids quercetin on the occurrence and proliferation of experimental mammary carcinoma. Methods DMBA induced mammary carcinoma was produced in rats. Seventy-nine female Sprague-Dawly rats were divided randomly into four groups: DMBA, DMBA with TAM, DMBA with quercetin and control. Chemicals had been administered to group A, group B, group C and group D respectively for 28 weeks. Samples of breasts were collected for light microscope observation and electromicroscope observation. Their expressions of proliferating cell nuclear antigen (PCNA) and the protein product of H-ras were examined by immunohistochemical staining. Results ①Mammary carcinoma incidence of group A(76.2%) was significantly higher than that of group B(40.9%), group C(45.5%) and group D(0%),P＜0.05, and there was no significant difference between group B and group C (P＞0.05), which indicated that quercetin could inhibit the occurrence of mammary carcinoma. ②Mean mammary tumor diameter of group A (2.37cm) was significantly larger than that of group B(1.82cm) and group C(1.71cm), P＜0.05, and there was no significant difference between group B and group C (P＞0.05), which indicated that quercetin could inhibit the growth of experimental mammary carcinoma. ③Immunohistochemical staining of PCNA showed significant difference between group A and group B, group A and group C (P＜0.05), with no significant difference between group B and group C (P＞0.05), which indicated that quercetin could inhibit the proliferation rate of tumor cells. ④Significant difference between group A and group B, group A and group C (P＜0.05), and no significant difference between group B and group C (P＞0.05), were noticed with immunohistochemical staining of H-ras protein product, which indicated that quercetin could inhibit the activity of Hras protein. Conclusion Quercetin could reduce the mammary carcinoma incidence and its degree of growth, and it may be related with its inhibitory effect on the activity of Hras and the proliferation of tumor cell.
Objective To investigate the effects of QUE on proliferation and DNA synthesis of cultured retinal pigment epithelium(RPE) cells with or without EGF. Methods With or without EGF, cultured RPE cells were treated with QUE by various concentrations(200,100,50,1mu;mol/L) and with QUE 200mu;mol/L at different times(24-168 hr), cells proliferation and DNA synthesis were evaluated by cell count method and the uptake of thymidine. The viability of cells was determined by trypanblue exclusion. Results The best concentration of QUE which inhibits proliferation and DNA synthesis of PRE cells was 200mu;mol/L. The significant inhibition effect of QUE occurred at 48hr, and the best inhibition of QUE occurred at 96hr. QUE had more powerful effect of antiproliferation on RPE cells, and the viability of RPE cells was over85%. Conclusion The results suggested that QUE could inhibit the proliferation of RPE cells in a dose-dependent and time-dependent manner, especially inhibit the proliferation induced by EGF stimulating. QUE had no cyto-toxic effect on RPE cells cultured in vitro. (Chin J Ocul Fundus Dis,1999,15:27-29)
Objective To investigate the effect of quercetin on human breast cancer cells and related mechanism. MethodsHuman breast cancer cell line MDA-MB-435S was treated by different concentrations of quercetin (12.5, 25, 50, 100 and 200 μmol/L). The inhibition ratio of human breast cancer cell was measured by trypan blue dye exclusion test, the proliferation cycle of human breast cancer cell was analyzed by flow cytometry and the expression of caspase-3 mRNA was determined by RT-PCR. ResultsQuercetin could inhibit the proliferation of breast cancer cell in the dose- and time-dependent manner. Quercetin could change the cell cycle of breast cancer cell, with the concentrations of quercetin increasing, the percentages of breast cancer cell at G0/G1 phase decreased, which increased at S phase, and increased at G2/M phase followed decrease. Quercetin could activate the expression of caspase-3 mRNA in breast cancer cell. ConclusionQuercetin can inhibit proliferation and induce apoptosis of human breast cancer cell, the mechanism may be associated with the change of cell cycle and the upregulation of caspase-3 expression.
Objective To probe into the roles of inositol 1, 4, 5-trisphosphate (IP3) and bcl-2 gene expression in inhabiting hepatocellular carcinoma of nude mice by quercetin. Methods Animals with hepatocellular carcinoma in quercetin group were treated with injection peritoneum of quercetin 50 mg/（kg·d ） for 3 weeks, while which in control group were treated with 0.4% DMSO of RPMI 1640 0.05 ml/（g·d）. Then the volume and the weight of tumors were measured, IP3, bcl-2 mRNA and bcl-2 protein were assayed by IP3-［3H］ Birtrak Assay, RT-PCR and Western blot respectively. Results The volume and weight of tumors in quercetin group were lower than those in control group 〔（15.8±10.1） mm3 vs. （52.3±26.5） mm3 in volume, （44.8±10.4） mg vs.（91.3±31.4） mg in weight， P＜0.01〕. Content of IP3 in quercetin group was lower than that in control group 〔（13.4±1.4） pmol/mg prot vs. （35.3±6.6） pmol/mg prot， P＜0.01〕. There was no significant difference in bcl-2 mRNA expression between quercetin group and control group 〔RI （the gray degree multiply area of bcl-2 /the gray degree multiply area of β-actin）： 0.55±0.05 vs. 0.79±0.19， P＞0.05〕， but the expression of bcl-2 protein in quercetin group was lower than that in control group (RI: 1.07±0.12 vs. 6.69±1.80, P＜0.01). Conclusion Quercetin can inhabit the growth of hepatocellular carcinoma tansplanted into liver of nude mice by reducing IP3 production and down-regulating bcl-2 gene expression.
Compound Huangbai liquid coating agent is a preparation that combines multiple traditional Chinese medicinal herbs and has shown significant efficacy in burn treatment. In recent years, the application of this coating agent in burn treatment has received widespread attention, and it plays a role in promoting wound healing, preventing infection, and reducing patient pain. This article reviews the research progress of compound Huangbai liquid coating agent in burn treatment, explores its mechanism of promoting wound healing, evaluates its current advantages and limitations in burn treatment, and provides scientific basis and theoretical support for its better use in burn treatment.