Effects of Mitofusin-2 Gene on Cell Proliferation and Chemotherapy Sensitivity of MCF-7

In order to evaluate the effect of mitofusin-2 gene （mfn2） on proliferation and chemotherapy sensitivity of human breast carcinoma cell line MCF-7 in vitro, pEGFPmfn2 plasmid carrying full length of mitofusin-2 gene was transfected, by using sofast, into MCF-7 cells. Mitofusin-2 gene expression in MCF-7 cells transfected by sofast after 48 h was detected by PCR and Western blotting, and the stable expression of GFP protein in MCF-7 cells by Western blot analysis. The proliferation of MCF-7 cells was assayed by MTT and cell counting. By using PI method, the effects of mfn2 on the cell cycle distribution of MCF-7 were measured. Annexin-Ⅴ/PI double labeling method was employed to detect the changes in apoptosis induced by chemotherapeutics before and after transfection. The results showed that the MCF-7 cells transfected with mfn2 gene could stably and highly express GFP protein. MTT assay revealed that after transfection of mfn2 cDNA, the proliferation of MCF-7 cells was significantly inhibited. DNA histogram showed that cells arrested in S phase, and the percentage of S phase cells was 42.7, 17.2 and 19.6 in mfn2 cDNA transfection group, blank plasmid transfection group and blank control group, respectively （P〈0.05）. The apoptosis ratio of the cells transfected with mfn2 gene was increased from 3.56% to 15.95%, that of the cells treated with camptothecin （CAMP） followed by mfn2 gene transfection was 69.6%, and that in blank plasmid transfection group and blank control group was 31.0% and 23.4% respectively （P〈0.05）. It was suggested that transfection of mfn2 gene could significantly inhibit the proliferation of MCF-7 cells and promote their sensitivity to CAMP with a synergic effect.     

Aidi Injection (艾迪注射液) Alters the Expression Profiles of MicroRNAs in Human Breast Cancer Cells

Objective: To investigate the effects of Aidi Injection (艾迪注射液 ADI) on the MicroRNAs (miRNA) expression profiles in human breast cancer cells and explore the potential targets of the cancer treatment. Methods: MCF-7 breast cancer cells were grown in RPMI 1640 medium supplemented with different concentrations of ADI. The inhibition of cell proliferation was measured by MTT assay. MCF-7 cells were treated by ADI with above 50% inhibiting concentration (IC50) for 48 h. The expression profiles of miRNA in ADI-treated and ADI-untreated MCF-7 cells were detected with miRNA microarray chips and the array data were verified by quantitative RT-PCR. MCF-7 cells were transiently transfected with miRNA mimics by liposome method. Potential mRNA targets were predicted by informatics analysis with TargetScan and PicTar software. Results: ADI significantly inhibited the proliferation of MCF-7 cells in a dose-dependent manner. The IC50 of ADI was 55.71 mg/mL after treatment for 48 h. The 60 mg/mL ADI was used as the therapeutic drug concentration. Microarray analysis identified 45 miRNAs that were up-regulated and 55 miRNAs that were down-regulated in response to ADI treatment. Many ADI-induced miRNAs were related to breast cancers. The microarray data were validated by qRT-PCR. Ectopic expression of 100 nmol/L mir-126 mimics significantly inhibited the proliferation of MCF-7 cells. The 12 potential target genes of mir-126 were predicted by both TargetScan and PicTar software. Conclusions: The miRNA may serve as therapeutic targets, and the modulation of miRNA expression is an important mechanism of ADI inhibiting breast cancer cell growth.     

Inhibitory Effects of Mild Hyperthermia plus Docetaxel Therapy on ER（＋/-） Breast Cancer Cells and Action Mechanisms

Summary： The purpose of this study was to verify that a combination of mild hyperthermia and do- cetaxel chemotherapy produces synergistic antitumor effects and to explore the action mechanisms of this treatment approach. The effects of docetaxel on the proliferation of cells from the estrogen receptor （ER）-positive human breast cancer cell line MCF-7 and the ER-negative human breast cancer cell line MDA-MB-453 were examined by 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay, and effective experimental concentrations of docetaxel were determined. The effects of mild hy- perthermia plus docetaxel therapy on apoptosis rate in the MCF-7 and MDA-MB-453 human breast cancer cell lines were analyzed by using flow cytometry with Annexin-V fluorescein isothiocyanate （FITC）/propidium iodide （PI） staining. The effects of these combined treatments on cell cycle progres- sion in the MCF-7 and MDA-MB-453 human breast cancer cell lines were examined by using flow cy- tometry. The effects of these combined treatments on the expression of apoptosis-related proteins and proteins in the mitogen-activated protein kinase （MAPK） pathways were analyzed by using Western blotting. The effects of these combined treatments on the expression of the heat shock protein 70 （HSP70） and the multi-drug resistance （MDR） gene product P-glycoprotein （Pgp） were examined by using Western blotting. The results showed that the half-maximal inhibitory concentration （IC50） of do- cetaxel for MCF-7 and MDA-MB-453 cells was 19.57±1.12 and 21.64±2.31 gmol/L respectively. Mild hyperthermia with docetaxel therapy could increase apoptosis rate in the MCF-7 and MDA-MB-453 cells. Apoptosis rate in MCF-7 and MDA-MB-453 cells was increased from （23.66±3.59）% and （18.51±3.17）% in docetaxel treatment group to （47.12±6.73）% and （55.16±7.42）% in mild hyperthermia plus docetaxel group, indicating that the mild hyperthermia and docetaxel therapeutic approaches exhib- ited significant synergistic antitumor effects. Treatments of mild hyperthermia plus docetaxel induced G2/M cell cycle arrest in the MCF-7 and MDA-MB-453 cells. Western blotting demonstrated that pro- teins in the MAPK pathway were expressed at higher levels in docetaxel-treated cells following mild hypothermia than those in cells treated with docetaxel alone. As compared with blank control group, cells from the mild hyperthermia plus docetaxel group exhibited significantly decreased B-cell lym- phoma 2 （Bcl-2） protein expression but slightly increased Bcl-2-associated X protein （Bax） expression. Western blotting results revealed that HSP70 and Pgp expression levels were significantly increased following mild hypothermia. It was concluded that treatments of mild hyperthermia plus docetaxel in- hibited the proliferation of human breast cancer cells, promoted apoptosis of breast cancer cells, and produced synergistic antitumor effects.     

Tetrandrine： A Potent Abrogator of G2 Checkpoint Function in Tumor Cells and Its Mechanism

Objective To assess the ability of tetrandrine （Tet） to enhance the sensitivity to irradiation and its mechanism in cell lines of human breast cancer p53-mutant MCF-7/ADR, p53-wild-type MCF-7 and human colon carcinoma p53-mutant HT-29 as well as in C26 colorectal carcinoma-bearing BALB/c mice. Methods MCF-7/ADR, HT-29 and MCF-7 cells were exposed to irradiation in the absence or presence of tetrandrine. The effect of Tet on the cytotoxicity of X-irradiation in these three cells was determined and the effect of tetrandrine on cell cycle arrest induced by irradiation in its absence or presence was studied by flow cytometry. Moreover, mitotic index measurement determined mitosis of cells to enter mitosis. Western blotting was employed to detect cyclin B1 and Cdc2 proteins in extracts from irradiated or non-irradiated cells of MCF-7/ADR, HT-29 and MCF-7 treated with tetrandrine at various concentrations. Tumor growth delay assay was conducted to determine the radio-sensitization of tetrandrine in vivo. Results Clonogenic assay showed that tetrandrine markedly enhanced the lethal effect of X-rays on p53-mutant MCF-7/ADR and HT-29 cells and the sensitization enhancement ratio （SER） of tetrandrine was 1.51 and 1.63, but its SER was only 1.1 in p53-wt MCF-7 cells. Irradiated p53-mutant MCF-7/ADR and HT-29 cells were only arrested in G2/M phase while MCF-7 cells were arrested in G1 and G2/M phases. Radiation-induced G2 phase arrests were abrogated by tetrandrine in a concentration-dependent manner in MCF-7/ADR and HT-29 cells, whereas redistribution within MCF-7 cell cycle changed slightly. The proportion of cells in M phase increased from 1.3% to 14.7% in MCF-7/ADR cells, and from 1.5% to 13.2% in HT-29 cells, but 2.4% to 7.1% in MCF-7 cells. Furthermore, the levels of cyclin B 1 and Cdc2 expression decreased after X-irradiation in MCF-7/ADR and HT-29 cells, and the mitotic index was also lower. Tet could reverse the decrease and induce the irradiated cells to enter mitosis （M phase）. Endosomatic experiment showed that tetrandrine caused tumor growth delay in irradiated mice. Conclusion Tetrandrine boosts the cell killing activity of irradiation both in vitro and in vivo. Tetrandrine is a potent abrogator for G2 checkpoint control and can sensitize the cells to radiation.     

miR-21 targets Fas ligand-mediated apoptosis in breast cancer cell line MCF-7

Over-expression of Fas ligand （FasL） on tumor cell surface can induce the apoptosis of spe- cific activated tumor infiltrating lymphocytes （TILs） via the Fas/FasL pathway, leading to the formation of a site of immune privilege surrounding the tumor mass for escaping immune surveillance and pro- moting tumor proliferation, invasion and metastasis. The blocking effect of miR-21 on FasL-mediated apoptosis in breast cancers was investigated in this study. The expression levels of miR-21 and FasL in human breast carcinoma cell lines were detected by using RT-PCR and Western blotting. FasL as a tar- get gene of miR-21 was identified by Luciferase assay. The apoptosis of Jurkat T lymphocytes induced by MCF-7 cells was determined by flow cytometry. It was found that in four human breast cancer cell lines, FasL expression level in MCF-7 cells was the highest, while miR-21 was down-regulated the most notably. After miR-21 expression in MCF-7 cells was up-regulated, FasL was identified as a target gene of miR-21. When the effector/target （E/T） ratio of MCF-7 cells and Jurkat cells was 10：1, 5：1 and 1：1, the inhibitory rate of apoptosis of Jurkat T lymphocytes induced by MCF-7 cells was 95.81%, 93.16% and 91.94%, respectively. It is suggested that in breast cancers miR-21 expression is negatively associ- ated with FasL expression, and FasL is a target gene of miR-21, miR-21 targeting and regulating FasL-mediated apoptosis will bring us the possibility of a new tumor immunotherapy via breaking tu- mor immune privilege.     

Shugan Liangxue Decoction (舒肝凉血方) Down-Regulates Estrogen Receptor α Expression in Breast Cancer Cells

Objective: To observe the effect of Shugan Liangxue Decoction(舒肝凉血方, SGLXD) on estrogen receptor α(ERα) in human breast cancer cells. Methods: The effect of SGLXD(0.85–5.10 mg/m L) on the proliferation of breast cancer cells were evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide(MTT) assay. The nuclear ERα protein levels in MCF-7, T47 D and ZR-75-1 cells which treated by SGLXD for 24 h were examined by western blot and immunofluorescence assay. MCF-7 and MDA-MB-231 cells were treated by 17β-estradiol(E2) with or without SGLXD, for 24 h, and the E2 targeted genes c-myc and bcl-2 protein product was evaluated by western blot. Results: SGLXD showed dose-dependent inhibition on the proliferation of MCF-7, T47 D and ZR-75-1 cells, but did not inhibit the proliferation of MDA-MB-231 cells. Furthermore, the promotive effect on cell growth induced by E2 was also significantly inhibited by SGLXD treatment. With the treatment of 1.70, 3.40, 5.10 mg/m L SGLXD, the nuclear ERα protein level was reduced to 88.1%, 70.4% and 60.9% in MCF-7 cells, and was decreased to 43.0%, 38.4% and 5.9% in ZR-75-1 cells as compared with the control group. In T47 D cells, the nuclear ERα protein was down-regulated to 51.3% and 4.3% by 3.40 and 5.10 mg/m L SGLXD treatment. The down-regulative effect of SGLXD on nuclear ERα was confirmed by immunofluorescence assay. SGLXD decreased the protein product of c-myc and bcl-2. Conclusions: SGLXD may exhibit selective inhibition effect on the proliferation of ER positive breast cancer cells. SGLXD reduced the nuclear ERα expression and the protein product of E2 target gene c-myc and bcl-2.     

Inhibition of cell proliferation by siRNA targeting hPRLR in breast cancer MCF-7 cell line

Objective： To study the inhibition of proliferation of breast cancer by small interfering RNA（siRNA） targeting human prolactin （hPRLR） and the underlying mechanisms. Methods：The siRNA targeting hPRLR was chemically synthesized and transfected into MCF-7 cells, the expression of hPRLR was analyzed by real-time quantitive PCR, cell growth inhibition was measured with MTT assay, cell cycle of the transfected cells was examined by flow cytometry, meanwhile, expression of cyclin D1 was tested by semi-quantitative RT-PCR, Results：24 h after transfection with 100 nmol/L siRNA-PRLR, the expression of hPRLR mRNA was suppressed by 65%, cells in G1 phase increased, but cells in S phase decreased. Down regulated hPRLR expression exhibited significant inhibition in cell proliferation. And the expression of cyclin D 1 was down regulated. Conclusion：The results indicate that siRNA-hPRLR is a useful tool for silencing hPRLR expression and inhibiting cell proliferation in breast cancer MCF-7 cell line, and it may be a possible new approach for breast cancer gene therapy.     

MIF对耐ADM人乳腺癌细胞MCF-7/ADM 体内外耐药逆转作用

目的：采用动物体内外结合方法探讨米非司酮（mifepristone, MIF）对耐阿霉素（adriamycin,ADM）人乳腺癌细胞MCF-7/ADM耐药逆转作用。方法：四甲基偶氮唑蓝法检测5 μmol/L MIF对 MCF-7/ADM体外耐药逆转作用。MCF-7/ADM接种裸鼠皮下构建裸鼠移植瘤模型,空白对照组（NS组）为0.2 mL生理盐水腹腔注射+0.5 mL食用油灌胃;ADM组为5 mg/kg ADM腹腔注射+0.5 mL食用油灌胃;MIF组为30 mg/kg MIF灌胃+0.2 mL生理盐水腹腔注射;ADM+MIF组为5 mg/kg ADM腹腔注射+30 mg/kg MIF灌胃。观察各组裸鼠移植瘤情况。结果：（1）5 μmol/L MIF对MCF-7/ADM细胞的抑制率小于5%,与未用MIF组的抑制率比较差异无统计学意义（P>0.05）。（2）ADM对MCF-7/ADM细胞的半抑制率为17.21 mg/L,而对非耐药乳腺癌细胞MCF-7细胞的半抑制率为0.42 mg/L,ADM对MCF-7/ADM细胞的半抑制率明显高于MCF-7的半抑制率（P＜0.05）。（3）5 μmol/L MIF与ADM联合处理MCF-7/ADM细胞后,MCF-7/ADM半抑制率为1.96 mg/L,明显低于单用ADM组的半抑制率（P＜0.05）。逆转ADM耐药倍数为8.78。（4）ADM+MIF组瘤体积［（232.5149±309.2377）mm3］均低于NS组的瘤体积［（962.2309±261.1313 ）mm3］（均P＜0.05）,也低于MIF组的瘤体积［（778.2846±42.6919）mm3］,还低于ADM组的瘤体积［（508.9648±16.2609） mm3］（均P＜0.05）。MIF+ADM组的瘤质量抑制率为78.0%。结论：MIF对耐阿霉素的人乳腺癌细胞MCF-7/ADM体内外均有逆转耐药性的作用。     

云南药用植物束花石斛提取物的体外抗氧化活性研究

目的研究药用植物束花石斛提取物的体外抗氧化活性．方法采用DPPH自由基清除法对束花石斛提取物的体外自由基清除作用进行研究．结果束花石斛的乙醇粗提物、乙酸乙酯和正丁醇提取物活性较好,IC50分别为0．39,0．27,0．40mg/mL．结论各提取部分均比芦丁（IC50=0．063mg/mL）抗氧化活性弱．     

Cytotoxicity screening of Melastoma malabathricum extracts on human breast cancer cell lines in vitro

ObjectiveTo screen the cytotoxic activity of Melastoma malabathricum (M. malabathricum) against human breast cancer cell line (MCF-7) in vitro.MethodsA three steps extraction protocol using n-hexane, chloroform and methanol as the solvents systems was carried out on leaves, stems and flowers of M. malabathricum. Dimethyl sulfoxide was used in extracts dilution and serial dilutions were conducted to obtain five different extract concentrations (100 μg/mL, 50 μg/mL, 25 μg/mL, 12.5 μg/mL and 6.25 μg/mL). The evaluation of cell growth was determined using methylene blue assay.ResultsMethanol extract from the leaves showed significant anticancer activity against MCF-7 cell lines with the IC₅₀ value of 7.14 μg/ml while methanol and chloroform extract from the flowers exhibited a moderate activity towards MCF-7 cell line with the IC₅₀ value of 33.63 μg/mL and 45.76 μg/mL respectively after 72 h of treatment.ConclusionsThe extracts from leaves and flowers of M. malabathricum showed promising anticancer activity toward human breast cancer cell lines with the lowest IC₅₀ at 7.14 μg/mL while the extracts from stems showed less growth inhibition activity.     

Antioxidant and antibacterial activity of different parts of Leucas aspera

Objective

To evaluate antioxidant, antimicrobial and cytotoxic activity of different parts (root, flower, leaf and stem) of Leucas aspera (L. aspera) (Labiatae).

Methods

Different parts of L. aspera were extracted with 80% (v/v) methanol. The methanol extracts were subjected to antioxidant, antimicrobial and brine shrimp lethality assay.

Results

All the extracts showed moderate to potent antioxidant activity, among which the root extract demonstrated the strongest antioxidant activity with the IC₅₀ value of 6.552 µg/mL. Methanol extract of root possessed antioxidant activity near the range of vitamin E and thus could be a potential rich source of natural antioxidant. In case of antimicrobial screening, crude extracts of root, flower, leaf and stem showed notable antibacterial activity against tested microorganisms. The root extract showed the highest mean zone of inhibition ranging from 9.0–11.0 mm against tested microorganisms, at a concentration of 100 mg/mL. In the brine shrimp lethality bioassay, it was evident that the methanol root extract did not show significant toxicity. The LC₅₀ value for 12 h and 24 h observation was 2.890 mg/mL and 1.417 mg/mL, respectively.

Conclusions

The present finding suggests that the methanol root extract of L. aspera could be developed as pharmaceutical products.     

In vitro antioxidant and anti–inflammatory activities of Korean blueberry (Vaccinium corymbosum L.) extracts

ObjectiveTo investigate in vitro antioxidant and anti-inflammatory activities of Korean blueberry (Vaccinium corymbosum L.).MethodsTotal phenolic and flavonoid contents of the Korean blueberry water and ethanol extracts were determined before determining the potential of the extracts as antioxidant. Antioxidant activity of the extracts was determined by following some well established methods for free radical scavenging such as 2,2-diphenyl-picrylhydrazyl hydrate, 1,2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonicacid), free radical induced DNA damage, superoxide dismutase-like and catalase assay etc. Furthermore, 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan and nitric oxide assay were performed to determine the anti-inflammatory activity of the extracts.ResultsTotal phenolic contents were found (115.0±3.0) and (4.2±3.0) mg GAE/100 g fresh mass for both extracts, respectively and flavonoid contents were (1 942.8±7.0) and (1 292.1±6.0) mg CE/100g fresh mass for water and ethonal extracts, respectively. Both the extracts displayed significant scavenging activity of some radicals such as 2,2-diphenyl-picrylhydrazyl hydrate (IC₅₀ at 1.8 mg/mL and 2.05 mg/mL, respectively), 1,2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonicacid) (IC₅₀ at 1.5 mg/mL and 1.6 mg/mL, respectively) and nitrite (IC₅₀ at 1.7 mg/mL and 1.5 mg/mL, respectively) etc. The extracts were found to prevent inflammation as well by reducing nitric oxide production and cytotoxicity in cell.ConclusionsThe findings suggest that the fresh Korean blueberry could be used as a source of natural antioxidants and anti-inflammatory agents.     

西印度醋栗对四氯化碳引起的大鼠和小鼠急性过氧化肝损伤的保护作用

目的：证实西印度醋栗（Phyllanthus acidus（L.）Skeels）的果实在传统医学中作为保肝药使用的药用用途。方法：连续5d分别给予各组大鼠西印度醋栗果实的70%乙醇提取物（100,200和400mg/kg口服）及对照药水飞蓟素（100mg/kg口服）并于第2天及第3天皮下注射四氯化碳（2mL/kg）。测定血清天冬氨酸氨基转移酶（aspartate transaminase,AST）、丙氨酸氨基转移酶（alanine transaminase,ALT）、碱性磷酸酶（alkaline phosphatase,ALP）、总胆红素以及总蛋白并进行肝脏组织病理学检测。检测大鼠肝组织匀浆中的氧化应激标记物如脂质过氧化反应（lipid peroxidation,LPO）、还原型谷胱甘肽（reduced glutathione,GSH）、超氧化物歧化酶（superoxide dismutase,SOD）、过氧化氢酶（catalase,CAT）以及谷胱甘肽过氧化物酶（glutathione peroxidase,GPx）以衡量西印度醋栗的体外抗氧化作用。此外,本实验还记录了伊维巴诱导的给药后小鼠睡眠时间,使用2,2-二苯基-1-苦基肼（2,2-diphenyl-1-picrylhydrazil,DPPH）法测定小鼠服药后的自由基清除率。结果：与对照组相比,西印度醋栗果实的乙醇提取物及水飞蓟素均显著降低了模型大鼠血清AST、ALT和ALP水平及LPO并升高了TP、GSH、SOD、CAT和GPx的水平（P〈0.01或P〈0.05）。大鼠肝脏组织的组织病理学切片结果也证实了以上实验结果。在小鼠实验中,与对照组相比,西印度醋栗果实的乙醇提取物显著缩短了伊维巴诱导的小鼠睡眠时间（P〈0.01）,并具有较高的DPPH清除率。结论：本研究的实验结果证实了西印度醋栗果实对四氯化碳引起的大鼠急性过氧化肝损伤的保护作用,机制可能与其抗氧化作用及自由基清除功能有关     

云南鼓槌石斛提取物体外自由基清除活性研究

目的 研究鼓槌石斛（Dendrobium chrysotoxum） 95％乙醇、石油醚、乙酸乙酯、正丁醇、甲醇五种粗提物体外自由基清除活性.方法 采用DPPH自由基清除法对云南鼓槌石斛五种提取物的体外自由基清除作用进行研究.结果 鼓槌石斛乙酸乙酯粗提物的自由基清除效果最显著,其IC50为0.12 mg/mL.结论 鼓槌石斛提取物在体外自由基清除活性方面有一定的应用价值.     

HPK1过表达对乳腺癌MCF-7和MDA-MB-231细胞增殖和凋亡的影响及其机制

目的：构建造血祖细胞激酶1（HPK1）慢病毒载体,探讨HPK1过表达对乳腺癌MCF-7和MDA-MB-231细胞增殖和凋亡的作用,阐明其可能的机制。方法：通过过表达HPK1的慢病毒感染细胞,获得稳定表达HPK1的细胞系（MCF-7-HPK1和MDA-MB-231-HPK1）,将2个细胞系分别分为3组,即空白组、对照组（空载体组）和过表达组;分别采用RT-PCR法和Western blotting法检测乳腺癌细胞中HPK1 mRNA和蛋白表达水平,MTT法检测细胞增殖率,流式细胞术检测细胞周期和凋亡率,Transwell法分析细胞的迁移能力,Western blotting法检测caspase 3、PTEN、MMP-9、MMP-2、Ki-67和HPK1蛋白表达水平。结果：与空白组和对照组比较,乳腺癌MCF-7和MDA-MB-231细胞过表达组中HPK1 mRNA和蛋白表达水平升高（P < 0.05）,细胞增殖率明显降低（P < 0.05）,细胞凋亡率明显升高（P < 0.05）,穿越Matrigel的细胞数明显减少（P < 0.05）,MCF-7细胞周期阻断在G₁期;过表达组细胞中caspase 3、PTEN蛋白表达水平上调（P < 0.05）,MMP-9、MMP-2、Ki-67蛋白表达水平降低（P < 0.05）。结论：HPK1过表达可抑制乳腺癌细胞MCF-7和MDA-MB-231的增殖及迁移并诱导凋亡,其可能与caspase 3、PTEN蛋白的表达上调及MMP-9、MMP-2和Ki-67蛋白的表达降低有关。     

Screening of antioxidant potential of selected barks of Indian medicinal plants by multiple in vitro assays

Objective To evaluate the antioxidant potential in herbal extract barks of five therapeutically important medicinal plants native to India, i.e. Crataeva nurvala Buch.-Ham., Buchanania lanzan Spreng., Aegle marmelos Corr., Dalbergia sissoo Roxb. ex DC., and Cedrela toona Roxb. Methods Standardized aqueous alcoholic extracts from the selected barks having different target radicals, such as superoxide radical, nitric oxide, ABTS radical, and peroxidative decomposition of phospholipids, were prepared and screened by multiple in vitro assays. These extracts were also tested for total phenolic and tannin content and correlated with antioxidant capacity. Results Total phenolic and tannin contents were found to be the highest in C. nurvala （195 GAE mg/g and 218.3 mg/g CE）. SOD mimetic activity was found to be the highest in Crataeva nurvula, although all barks showed activity more than IO3 units/mg extract. Lipid peroxidation inhibitory potential was found to be the highest in Crataeva nurvala （83.4% inhibition of MDA formation/10 μg extract）, and also showed a comparatively high NO quenching capacity （45.5% per 10 μg extract）. The highest NO quenching potential was found in Aegle marmelos （47.3% per 10 μg extract）. Cedrela toona showed the lowest LPO inhibitory potential and NO quenching capacity （50.5% and 30.5%, respectively）. Buchanania lanzan, a medicinal plant extensively used for inflammatory disorders and Dalbergia sissoo also showed 72.5% and 69.1% LPO inhibitory potential/10 μg extract. Trolox equivalent antioxidant capacity ranged from 0.24 to 0.39 mmol/L TEAC/mg extract, indicating that all the barks tested had ABTS^＋ radical quenching capacity. Conclusion Bark of Crataeva nurvula has the highest antioxidant capacity and a positive correlation between antioxidant activity and their plendic content was found.     

吲哚类化合物GY3通过AMPK/COX-2信号通路诱导乳腺癌细胞MCF-7凋亡

目的 探究吲哚类化合物GY3对人乳腺癌MCF-7细胞增殖和凋亡的作用,及其对腺苷酸活化蛋白激酶/环氧合酶-2(AMPK/COX-2)信号通路的影响.方法 以AMPK激活剂5-氨基4.甲酰胺咪唑核糖核苷酸(AICAR)和COX-2抑制剂塞来昔布为阳性对照药物,利用MTT方法、流式细胞术检测不同浓度的GY3、AICAR、塞来昔布及AICAR+塞来昔布联用对MCF-7细胞增殖和凋亡的影响;用Western blot方法检测不同浓度GY3和AMPK抑制剂Compound C联用对MCF-7细胞乙酰辅酶A羧化酶、磷酸化乙酰辅酶A羧化酶(P-ACC)、COX-2蛋白表达的影响.结果 GY3可上调P-ACC的表达、下调COX-2的表达(P＜0.01,P＜0.05),同时显著降低MCF-7细胞的活力(P ＜0.01,P＜0.05),抑制MCF-7细胞的增殖,诱导MCF-7细胞发生凋亡(P＜0.05),并且呈现一定的浓度依赖性;Compound C可有效地阻断GY3对AMPK的激活和COX-2的抑制作用,其作用与AIC-AR、塞来昔布及AICAR+塞来昔布联用的比较显示GY3的抑癌活性较高.结论 GY3能有效抑制乳腺癌细胞MCF-7的增殖,诱导其凋亡,其机制与激活AMPK、抑制COX-2的表达有关.