A new aurone glycoside from Veratrum dahuricum (Turcz.) Loes. f / 药学学报

To study the chemical constituents of Veratrum dahuricum (Turcz.) Loes. f., a new aurone glycoside named as (Z)-7, 4'-dimethoxy-6-hydroxyl-aurone-4-O-β-glucopyranoside was isolated from the 95% ethanol extracts of the rhizomes and roots of Veratrum dahuricum (Turcz.) Loes. f. by repeated column chromatography on silica gel and recrystallization. Its structure was established by extensive spectroscopic analyses, and its cytotoxicities against HepG-2, MCF7 and A549 cell lines were measured in vitro.

Chemical constituents from Psoralea corylifolia and their antioxidant alpha-glucosidase inhibitory and antimicrobial activities / 中国中药杂志

Twelve compounds were isolated from Psoralea corylifolia and their structures were identified as isopsoralen (1), psoralen (2), 8-methoxypsoralen (3), psoralidin (4), corylin (5), bavachin (6), daidzein (7), corylifolinin (8), bavachinin (9), neobavaisoflavone (10), daidzin (11) and astragalin (12). The results showed that psoralidin had the activity of scavenging DPPH free radicals activity (IC50 43.85 mg x L(-1)). Psoralidin (IC50 1.32 mg x L(-1))c, oryfolin (IC50 4.97 mg x L(-1)), daidzin (IC50 10.47 mg x S(-1)), daidzein (IC50 34.22 mg) x L(-1)) and astragalin (IC50 31.27 mg x L(-1)) had the activity of scavenging ABTS free radical. Psoralidin (IC50 40.74 mg x L(-1)), coryfolin (IC50 45.73 mg x L(-1)) and daidzein (IC50 49.44 mg x L(-1)) had alpha-glucosidase inhibitory activity. Corylifolinin and neobavaisoflavone had significantly effect of inhibiting SA, MRSA and ESBLs-SA (MIC 0. 781 3, 1.562, 5, 0.781 25 microg x disc(-1) and 6.25, 6.25, 6.25 microg x disc(-1).

Effect of berberine on sensitivity enhances of K562/DOX cells to doxorubicin / 中国药学杂志

OBJECTIVE: To investigate berberine's potential to enhance the sensitivity of doxorubicin-resistant human leukemia cell lines (K562/DOX) to doxorubicin in vitro. METHODS: MTT assay was performed to determine the effect of berberine on the sensitivity of K562/DOX cells to doxorubicin. Doxorubicin accumulation assay was performed by Arrary Scan VTI HCS600 High-Contents. The effect of berberine on doxorubicin-induced cell apoptosis was tested by PI/Hoechst 33342 assay. The efflux activity of P-gp was investigated by measuring the accumulation of the rhodamine 123 after treatment with berberine. RESULTS: μmol · L-1 of berberine, as a wild dose, reduced IC50 of doxorubicin to K562/DOX cells by 1.5 times. 1 μmol · L-1 of berberine showed the enhancement effect on doxorubicin-induced apoptosis. The increase of doxorubicin and rhodamine 123 accumulation was observed in K562/ DOX cells treated with 1 μmol · L-1 of berberine which indicated the inhibition of the activity of P-gp. CONCLUSION: Berberine is shown to effectively enhance chemosensitivity of K562/DOX cells to Dox by inhibiting the efflux activity of P-gp.

Prosapogenin A inhibits cell growth of MCF7 via downregulating STAT3 and glycometabolism-related gene / 药学学报

This study is to investigate the inhibitory effect and mechanism of prosapogenin A (PSA) on MCF7. MTT assay was performed to determine the inhibitory effect of PSA on MCF7 cells. PI/Hoechst 33342 double staining was used to detect cell apoptosis. RT-PCR was used to test the mRNA levels of STAT3, GLUT1, HK and PFKL. Western blotting was performed to determine the expression of STAT3 and pSTAT3 protein in MCF7 cells. The results showed that PSA could dose-dependently inhibit cell growth of MCF7 followed by IC50 of 9.65 micrmol x L(-1) and promote cell apoptosis of MCF7. Reduced mRNA levels of STAT3, HK and PFKL were observed in MCF7 cells treated with 5 micromol x L(-1) of PSA. PSA also decreased the level of pSTAT3 protein. STAT3 siRNA caused decrease of mRNA of GLUT1, HK and PFKL which indicated STAT3 could regulate the expressions of GLUT1, HK and PFKL. The results suggested that PSA could inhibit cell growth and promote cell apoptosis of MCF7 via inhibition of STAT3 and glycometabolism-related gene.

Endogenous cystathionine-gamma-lyase/hydrogen sulfide pathway regulates apoptosis of HepG2 cells / 药学学报

This study is to investigate the role of endogenous CSE/H2S in regulating apoptosis of HepG2 cells. MTT and Trypan blue assay were performed to determine the effect of CSE inhibitor PAG and CSE siRNA on proliferation of HepG2. Production of H2S from HepG2 cells was assessed spectrophotometrically using N, N-dimethyl-p-phenylenediamine-dihydrochloride. Cells apoptosis was detected by means of double staining of Hoechst 33342 and PI with Array Scan V(TI)HCS600 High-Contents. Dihydroethidine (DHE) and 2', 7'-dichlorodihydrofluorescein diacetate (DCFH-DA) assay was used to determine intracellular superoxide anion and ROS level. Reduced glutathione (GSH) was determined by OxiSelect Total Glutathione Assay Kit. Recombinant plasmid pcDNA 3.1/myc-His(-)-CSE was constructed and transfected into 293T cells to rescue the ROS and GSH level to further investigate the effect of CSE/H2S on ROS and GSH. Western blotting was performed to test the effect of CSE siRNA on expression of activated caspase 3 and p-AKT and Nrf2 protein. The results showed that PAG and CSE siRNA could significantly decrease the production of H2S in HepG2 cells and inhibit the proliferation of HepG2 cells at a dose-dependent and time-dependent manner, respectively. PAG and CSE siRNA could promote the cell apoptosis of HepG2 cells. Moreover, PAG and CSE siRNA induced increased ROS generation and depletion of the critical antioxidant GSH and recombinant plasmid pcDNA 3.1/myc-His(-)-CSE rescued the level of ROS and GSH. Meanwhile, CSE siRNA increased the expression of activated caspase 3, but CSE siRNA did not affect the expression of p-AKT and Nrf2. These results suggested that the CSE/H2S pathway was involved in suppression of HepG2 cell growth and promoted apoptosis of HepG2 cells in an oxidative stress-dependent manner.

Small interfering RNA targeting STAT3 enhances antitumor activity of doxorubicin / 药学学报

This study is to investigate the effect of small interfering RNA targeting STAT3 (STAT3-siRNA) enhancing antitumor activity of doxorubicin. RT-PCR and Western blotting were used to test the expression of STAT3 mRNA and protein in the HepG2, HeLa and K562/DOX cells and the effect of STAT3-siRNA on the expression of STAT3 mRNA and protein. MTT and Trypan blue assay were performed to determine the inhibitory effect of STAT3-siRNA on HepG2, HeLa and K562/DOX cells and the effect of STAT3-siRNA enhancing antitumor activity of doxorubicin. The effects of STAT3-siRNA on intracellular accumulation of doxorubicin and cell apoptosis were performed by Arrary Scan V(TI)HCS600 High-Contents. The results showed that STAT3 gene, STAT3 and pSTAT3 protein were highly expressed in HepG2, HeLa and K562/DOX cells and STAT3-siRNA decreased the expression of STAT3 mRNA and protein. STAT3-siRNA inhibited the growth of HepG2, HeLa and K562/DOX cells. STAT3-siRNA in combination with doxorubicin decreased by 3.13, 5.22 and 1.74 fold of IC50 of HepG2, HeLa and K562/DOX cells compared with doxorubicin only. Intracellular accumulation of doxorubicin increased by 16.8%, 12.87% and 25.67% respectively in HepG2, HeLa and K562/DOX cells in the presence of STAT3-siRNA. An enhancement of doxorubicin-induced cell apoptosis was observed in HepG2, HeLa and K562/DOX cells treated with STAT3-siRNA. The results suggested that STAT3-siRNA could enhance the antitumor activity of doxorubicin on HepG2, HeLa and K562/DOX cells.

Pregnane X receptor and multidrug resistance / 国际药学研究杂志

Multidrug resistance(MDR) is the leading cause of treatment failure in cancer therapy. Overexpression of the ATP-binding cassette (ABC) transporter family increases the cellular efflux, decreases the effectiveness of chemotherapeutic agents,and results in MDR. In particular,overexpression of P-glycoprotein and its encoding genes(mdr1) is the major mechanism. It is feasible for overcoming MDR by studying the factors affecting mdr1 gene expression so as to block the expression of mdr1. Pregnane X receptor(PXR) can regulate the expression of MDR proteins, suggesting that it be possible to overcome drug resistance by regulating PXR. In this paper,the relation between PXR and MDR and recent development of PXR antagonists to pharmacologically modulate PXR are reviewed. The review proposes that selectively preventing the elevation of MDR levels by regulating PXR rather than non-selectively inhibiting the MDR activity by using MDR inhibitors can be a less toxic approach to overcome drug resistance during cancer therapy.

Reversal effect of isotetrandrine, an isoquinoline alkaloid extracted from Caulis Mahoniae, on P-glycoprotein-mediated doxorubicin-resistance in human breast cancer (MCF-7/DOX) cells / 药学学报

This study investigated the reversal effect of isotetrandrine, an isoquinoline alkaloid extracted from Caulis mahoniae, on P-glycoprotein-mediated multidrug resistance in human breast cancer doxorubicin-resistant (MCF-7/DOX) cells. RT-PCR assay and immunity histochemistry assay were used to determine the expression level of mdrl gene and P-gp in MCF-7/DOX cells to elucidate resistant character of MCF-7/DOX cells. The activity of isotetrandine to enhance doxorubicin cytotoxicity was tested using MTT (3-(4, 5-dimethyhthiazol)-2,5 -diphenyltetrazolium bromide) assay and was evaluated by the reversal fold (RF) values. Intracellular accumulation of doxorubicin was assessed by the determination of doxorubicin-associated fluorescence intensity. Effect of isotetrandrine on the expression level of P-gp in MCF-7/DOX cells was then determined by immunity histochemistry assay. The ability of isotetrandrine to inhibit P-gp function was evaluated by detecting the accumulation and efflux of rhodamine 123 (Rh123) with flow cytometry (FCM). Verapamil was employed as a comparative agent in whole experiment. The results indicated that MCF-7/DOX cells had phenotype of MDR and that the positive expression of P-gp was their resistant character. 10 microg x mL(-1) isotetrandrine could distinctly enhance cytotoxicity of DOX in MCF-7/DOX cells and reversal fold (RF) was significantly higher than that of verapamil (P < 0.05), but it hardly affected cytotoxicity of DOX in MCF-7 cells and the expression level of P-gp in MCF-7/DOX cells. The ability of isotetrandrine to inhibit P-gp function was reversible, because incubation of MCF-7/DOX cells with isotetrandrine caused a marked increase in uptake and a notable decrease in efflux of Rh123 and a marked increase of intracellular DOX concentrations. In conclusion, isotetrandrine exhibited potent effect on the reversal of P-gp-mediated MDR in vitro, suggesting that it might become a candidate of effective MDR reversing agent in cancer chemotherapy.

Expression of Matrix Metalloproteinase-1 and Tissue Inhibitor of Metalloproteinase-1 in Fibra Muscular Torticollis in Children / 实用儿科临床杂志

Objective To explore the expressions of matrix metalloproteinases-1(MMP-1) and tissue inhibitor of metalloproteinase-1(TIMP-1) in sternomastoid muscle and explore the pathogenesis of sternomastoid muscle fibrosis in congenital fibra muscular torticollis in children.Methods The hyperplastic state of collagen fiber were determine by Masson collagen stainning method and muscular torticollis and fibra torticollis was differed,obtained 22 cases of the fibra torticollis group.Immunohistochemical method was used to determine the expression of MMP-1 and TIMP-1 in sternomastoid muscle of fibra torticollis and compared them with 6 cases of control group.Results By the immunohistochemical method,the expression of MMP-1 in the experiment group significantly decreased than that in control group(P0.05).Conclusion In congenital fibra torticollis,the sternomastoid muscle fibrosis is related to the decrease of MMP-1.