Induction of apoptosis and inhibition of PI3K/Akt pathway in PC-3 and LNCaP prostate cancer cells by ethanolic neem leaf extract

Aim of the study

The present study is aimed to delineate the effect of ethanolic neem leaf extract on PI3K/Akt and apoptotic pathway in prostate cancer cell lines (PC-3 and LNCaP).

Materials and methods

To test the hypothesis, two different prostate cancer cell lines LNCaP (androgen dependent) and PC-3 (androgen independent) were taken. Cells were exposed to various concentrations of ethanolic neem leaf extract (ENLE) (25-125 μg/ml). The doses were fixed by cell viability (MTT) assay. For apoptotic detection in situ apoptosis assay, caspase-3 activity and protein expression of cytochrome c and Poly-ADP Ribose Polymerase (PARP) were analysed as well as mRNA expression of Bcl-2 family proteins was studied by RT-PCR. The phosphoinositide 3-kinase (PI3K) and p-Akt were analysed by western blotting and mRNA expression of Akt 1 and 2, PTEN was performed by RT-PCR. Immunoblotting of cyclin D1 and p21 was done to access the inhibition of cell proliferation.

Results

ENLE gives 50% inhibition at a dose of 100 μg/ml in both PC-3 and LNCaP cells and considered as effective dose. ENLE decreased the protein expression of PI3K as well as p-Akt and the mRNA expression of Akt 1and 2 in both the cells. There was a significant decrease in mRNA expression of PTEN in LNCaP cells. ENLE induced apoptosis and inhibited cell proliferation by inhibiting PI3K/Akt pathway. Decrease in p-Akt leads to increase in the protein level of Bad, p21 and decrease in the cyclin D1, respectively. ENLE treatment increased the cytochrome c expression and caspase-3 activity as well as regulated the mRNA expression of Bcl-2 family proteins thereby inducing apoptosis to both the cell lines. In situ apoptosis assay showed increased red fluorescence in 100 μg/ml of ENLE in both PC-3 and LNCaP cell lines.

Conclusions

The results suggested that ENLE induces apoptosis and inhibits cell proliferation through inhibiting PI3K/Akt pathway in both PC-3 and LNCaP cells.     

Anti-tumor activity and relative mechanism of ethanolic extract of Marsdenia tenacissima (Asclepiadaceae) against human hematologic neoplasm in vitro and in vivo

Ethnopharmacological relevance

Marsdenia tenacissima, a traditional Chinese medicinal herb, endemic to Yunnan Province is widely used to treat cough, asthma, expectorant, esophageal cancer, gastric cancer, lung cancer, and hepatocellular carcinoma. The aim of this study was to evaluate in vitro and in vivo anti-hematologic neoplasm potential of the ethanolic extract of this herb (crude ethanolic extract of Marsdenia tenacissima, CME) and by using different assays to elucidate its possible mechanism of action.

Materials and methods

The cytotoxicity of CME on tumor cells and peripheral blood mononuclear cells (PBMCs) was evaluated using MTT and apoptosis assays. We also tested the effect of CME on colony formation inhibition and cell cycle distribution of tumor cells. The protein expressions of Cyclin D1, Bax, Bcl-2, caspase-3 and caspase-9 were detected through Western blotting. In vivo anti-tumor effect was evaluated by measuring tumor volume changes, measuring tumor weight, evaluation of tumor microvessel density (MVD) and TUNEL staining by using immunohistochemistry staining in tumor models of nude mice.

Results

Marsdenia tenacissima ethanolic extract exhibited effects of proliferation inhibition and induction of apoptosis on human hematologic neoplasm tumor cells in vitro, as well as hematologic neoplasm growth in vivo.

Conclusion

This study clearly indicated that the ethanolic extract of Marsdenia tenacissima displayed strong anti-tumor effects against hematologic neoplasm cells and could induce tumor cells apoptosis in vitro and in vivo, and also had a significant anti-angiogenic effect in vivo against tumor cell apoptosis. Its multi-mechanism of action might be associated with the cell cycle (G0/G1) arrest, induction of apoptosis through up-regulation protein expressions of Bax, caspase-9 and caspase-3 genes and down-regulation of the expressions of Cyclin D1 and Bcl-2 genes, a decrease in tumor microvessel density and an increase of TUNEL-positive cells in vivo. These findings provided the molecular theoretical basis of clinical application.     

A steroid fraction of chloroform extract from bee pollen of Brassica campestris induces apoptosis in human prostate cancer PC-3 cells

Bee pollen of Brassica campestris L. is widely used in China as a natural food supplement and an herbal medicine in strengthening the body's resistance against diseases including cancer. The present study was carried out to investigate the effect of a steroid fraction of chloroform extract from bee pollen of Brassica campestris L. on human cancer cell viability. Our studies show that among nine cancer cell lines of different origin (PC-3, LNCaP, MCF-7, Hela, BEL-7402, BCG-823, KB, A549 and HO8910), this steroid fraction displayed the strongest cytotoxicity in human prostate cancer PC-3 cells. The mode of cell death appeared to be apoptosis in PC-3 cells, as shown by flow-cytometric analysis and fluorescence microscopes. Caspase-3 activity was obviously enhanced after the cells were treated with the fraction. A time-dependent decrease in the expression of anti-apoptotic protein Bcl-2 was also observed by Western blot analysis. It is suggested that the steroid fraction could induce cytotoxicity in prostate cancer PC-3 cells by triggering apoptosis. The studies indicate that the steroid fraction of chloroform extract from bee pollen of Brassica campestris L. may be a promising candidate for the treatment of advanced prostate cancer.     

Anti-tumor and pro-apoptotic activity of ethanolic extract and its various fractions from Polytrichum commune L.ex Hedw in L1210 cells

Ethnopharmacological relevance

Polytrichum commune L.ex Hedw is a traditional Chinese herb for treatment of fever, hemostatic, uterine prolapse and especially for lymphocytic leukemia, but the antitumor effect and its potential mechanism remains unclear.

Aims of the study

The present study was to investigate the possible anti-proliferative activity of ethanolic extract and the organic fractions from P. commune on murine leukemia L1210 cells.

Materials and methods

The content of ethanolic extract and its fractions was performed on HPLC analysis with gradient elution. L1210 cells were treated with different concentrations of ethanolic extract and its fractions at different time intervals. Cell viability was evaluated using MTT assay. Apoptotic cell death was monitored by nuclear condensation and confirmed by exposure of phosphatidylserine to outer leaflet of plasma membrane. Loss of mitochondrial membrane potential was analyzed by flow cytometry using rhodamine 123 staining.

Results

The obtained results showed that the cell viability of L1210 cells was reduced by ethanolic extract of P. commune in a concentration-dependent manner, and the IC₅₀ value was about 77.22 μg/ml at 24 h post treatment. The ethylacetate fraction displayed higher anti-tumor effect than that of chloroform and butanol fractions with 32.29 μg/ml (IC₅₀ value, 48 h). Microscopy studies revealed that ethanolic extract and ethylacetate fraction treated cells showed morphological characteristics of apoptosis such as chromatin condensation and DNA aggregation. Further, Annexin V-PE/ 7-AAD double staining showing the out leaflet of phosphatidylserine and the decline of mitochondrial membrane potential by flow cytometry confirmed that the extracts do, in fact, induce apoptosis in L1210 cells.

Conclusion

This is the first report on anti-tumor and pro-apoptotic effect of P. commune in cultured leukemia cells, which provides scientific basis for its usefulness as traditional medicine. Further studies are needed to confirm the precise mechanism not only the crude extract but as well the monomeric chemical substances of Polytrichum commune L.ex Hedw.     

Physalin F from Physalis minima L. triggers apoptosis-based cytotoxic mechanism in T-47D cells through the activation caspase-3- and c-myc-dependent pathways

Ethnopharmacological relevance

Physalin F (a secosteroid derivative), is well recognized as a potent anticancer compound from Physalis minima L., a plant that is traditionally used to treat cancer. However, the exact molecular anticancer mechanism remains to be elucidated.

Aim of the study

We have recently reported the apoptosis-based cytotoxic effect of the chloroform extract of this plant. Here, we investigated the cytotoxicity and possible cell death mechanism elicited by the active constituent, physalin F on human breast T-47D carcinoma.

Materials and methods

Cytotoxic-guided fractionation of the chloroform extract of Physalis minima has led to the isolation of physalin F. The cytotoxicity activity was assayed using MTS assay. The effect of the compound to induce apoptosis was determined by biochemical and morphological observations through DeadEnd Colorimetric and annexin V assays, respectively, and RT-PCR analysis of mRNA expression of the apoptotic-associated genes.

Results

Cytotoxicity screening of physalin F displayed a remarkable dose-dependant inhibitory effect on T-47D cells with lower EC₅₀ value (3.60 μg/ml) than the crude extract. mRNA expression analysis revealed the co-regulation of c-myc- and caspase-3-apoptotic genes in the treated cells with the peak expression at 9 and 12 h of treatment, respectively. This apoptotic mechanism is reconfirmed by DNA fragmentation and phosphatidylserine externalization.

Conclusion

These findings indicate that physalin F may potentially act as a chemopreventive and/or chemotherapeutic agent by triggering apoptosis mechanism via the activation of caspase-3 and c-myc pathways in T-47D cells.     

In vitro anti-breast cancer activity of ethanolic extract of Wrightia tomentosa: Role of pro-apoptotic effects of oleanolic acid and urosolic acid

Ethnopharmacological relevance

Wrightia tomentosa Roem. & Schult. (Apocynaceae) is known in the traditional medicine for anti-cancer activity along with other broad indications like snake and scorpion bites, renal complications, menstrual disorders etc. However, the anti-cancer activity of this plant or its constituents has never been studied systematically in any cancer types so far.

Aim of the study

To evaluate the anti-cancer activities of the ethanolic extract of W. tomentosa and identified constituent active molecule(s) against breast cancer.

Material and methods

Powdered leaves of W. tomentosa were extracted with ethanol. The ethanolic extract, subsequent hexane fractions and fraction F-4 of W. tomentosa were tested for its anti-proliferative and pro-apoptotic effects in breast cancer cells MCF-7 and MDA-MB-231.

Results

The ethanolic extract, subsequent hexane fractions and fraction F-4 of W. tomentosa inhibited the proliferation of human breast cancer cell lines, MCF-7 and MDA-MB-231. The fraction F-4 obtained from hexane fraction inhibited proliferation of MCF-7 and MDA-MB-231 cells in concentration and time dependent manner with IC₅₀ of 50 μg/ml and 30 μg/ml for 24 h, 28 μg/ml and 22 μg/ml for 48 h and 25 μg/ml and 20 μg/ml for 72 h respectively. The fraction F-4 induced G1 cell cycle arrest, reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and subsequent apoptosis. Apoptosis is indicated in terms of increased Bax/Bcl-2 ratio, enhanced Annexin-V positivity, caspase 8 activation and DNA fragmentation. The active molecule isolated from fraction F-4, oleanolic acid and urosolic acid inhibited cell proliferation of MCF-7 and MDA-MB-231 cells at IC₅₀ value of 7.5 μM and 7.0 μM respectively, whereas there is devoid of significant cell inhibiting activity in non-cancer originated cells, HEK-293. In both MCF-7 and MDA-MB-231, oleanolic acid and urosolic acid induced cell cycle arrest and apoptosis as indicated by significant increase in Annexin-V positive apoptotic cell counts.

Conclusion

Our results suggest that W. tomentosa extracts has significant anti-cancer activity against breast cancer cells due to induction of apoptosis pathway. Olenolic and urosolic acid are important constituent molecules in the extract responsible for anti-cancer activity of W. tomentosa.     

Anti-inflammatory and anti-nociceptive activities of Platanus orientalis Linn. and its ulcerogenic risk evaluation

Ethnopharmacological relevance

Leaves of Platanus orientalis Linn. are used in folk medicine as a wound-healer and ophthalmologic agent. Phytol derivatives from the leaves of plane-tree show anti-ulcer activity. Its analgesic and anti-inflammatory effects for knee pain were known to Persian scientists and hakims.

Materials and methods

The ethanolic extract of Platanus orientalis Linn. and its various fractions were given at a dose of 100 mg/kg po and 200 mg/kg po for testing their anti-inflammatory activity by carrageenan induced hind paw edema. The analgesic activity of the ethanolic extract and its fractions has been carried out by tail-flick method and writhing test at a dosage of 200 mg/kg po. Gastric ulceration studies have been further carried out to study the ulcerogenic risk evaluation of the ethanolic extract and its various fractions at a dose of 600 mg/kg body weight.

Results

Among the tested fractions, chloroform fraction exhibited better inhibition (68.33%) at 200 mg/kg po dosage when compared to the standard drug Ibuprofen (66.66%) after 3 h in the carrageenan induced hind paw edema. The ethanolic extract and all its fractions especially the chloroform (p<0.01) showed significant analgesic activity with insignificant ulceration as compared to the standard drug i.e. Ibuprofen. The histopathological study of ethanolic extract and its fractions revealed that none of them cause ulcer.

Conclusion

The present study indicates that Platanus orientalis Linn. has significant anti-inflammatory and analgesic effect.     

Genotoxic and mutagenic properties of Bauhinia platypetala extract,a traditional Brazilian medicinal plant

Ethnopharmacological relevance

Bauhinia platypetala Burch. is a traditionally used Brazilian medicinal plant, although no evidence in the literature substantiates the safety of its use.

Aim of the study

The aim of this study was to investigate the safety of the ethanolic extract and the ethereal fraction of B. platypetala leaves.

Materials and methods

The identification of chemical compounds from the B. platypetala ethanolic extract and its ethereal fraction was performed by GC/MS and ESI-MS/MS. The plant’s toxicological, cytotoxic, mutagenic and genotoxic properties were determined in Saccharomyces cerevisiae strains and V79 cell culture by survival assays and comet assay.

Results

The major compound identified in the B. platypetala ethanolic extract is palmitic acid, kaempferitirin and quercitrin, while the B. platypetala ethereal fraction was found to be rich in phytol, gamma-sitosterol and vitamin E. Moreover, the results indicated that the B. platypetala ethanolic extract has an anti-oxidative effect against H₂O₂ in yeast. In addition, the B. platypetala ethanolic extract did not induce mutagenic effects on the S. cerevisiae N123 strain, but the ethereal fraction of B. platypetala at higher concentrations (250–500 μg/mL) induced cytotoxicity and mutagenicity. A slight cytotoxic effect was observed in mammalian V79 cells; however, both the B. platypetala ethanolic extract and its ethereal fraction were able to induce DNA strand breaks in V79 cells, as detected by the alkaline comet assay.

Conclusion

The B. platypetala ethanolic extract has antioxidant action and showed absence of mutagenic effects in yeast S. cerevisiae. On the other hand B. platypetala ethereal fraction is mutagenic and does not show antioxidant activity in yeast. In mammalian cells B. platypetala ethanolic extract and it's ethereal fraction induce cyotoxic and genotoxic action.     

Protective effects of Puerariae radix extract and its single compounds on methylglyoxal-induced apoptosis in human retinal pigment epithelial cells

Ethnopharmacological relevance

In Korea, Puerariae radix is a medicinal plant traditionally used to treat various diseases including diabetes mellitus. To provide pharmacological basis for Puerariae radix in the treatment of diabetes, we investigated the protective effects of the ethanolic extract and its single compounds on apoptosis associated with glycation in human retinal pigment epithelial (RPE) cells.

Materials and methods

In the present work, a quantified ethanolic extract or single compounds of Puerariae radix were selected to determine its anti-apoptotic effect in human RPE cells cultured with methylglyoxal (MG), which is a stimulator of glycation. To assess the protective effect of the extract or single compounds, the cytotoxicity assessment was performed using an MTT assay in the human RPE cells. Selected active compounds or extracts were tested by FACS analysis with annexin V staining for apoptosis.

Results

Daidzein (1), daidzin (2), puerarin (3), 3'-hydroxy-daidzein 8-C-apiosyl (1→6) glucoside (4), and daidzein 8-C-apiosyl (1→6) glucoside (5), and pueroside B (6) were isolated from an ethanolic extract of Puerariae radix. MG-induced apoptosis was completely inhibited by Puerariae radix, ethanolic extract, and single compounds. Of the six major compounds, daidzin (2) and 3'-hydroxy-daidzein 8-C-apiosyl (1→6) glucoside (4) significantly inhibited MG-induced apoptosis.

Conclusion

Our results provide the first evidence that, due to its anti-glycation effect, Puerariae radix extract could inhibit MG-induced apoptosis in the cultured human RPE cells. These data suggest that Puerariae radix extract, especially its single compounds daidzin and 3'-hydroxy-daidzein 8-C-apiosyl (1→6) glucoside, has potential utility as a preventive agent for glycation-related diabetic retinopathy.     

构树叶总黄酮调控Bcl-2与Bax蛋白表达及caspase-3活性诱导HepG-2细胞凋亡的研究

目的:研究构树叶总黄酮(total flavonoids of Broussonetia papyrifera,TFBP)诱导HepG-2细胞凋亡的机制。方法:采用体外细胞培养方法,取对数生长期人肝癌HepG-2细胞,随机分为药物组和对照组,药物组用3,6,9,12 g·L-1不同质量浓度TFBP作用人肝癌HepG-2细胞24,48,72 h后,应用MTT法检测TFBP对人肝癌细胞HepG-2生长抑制作用;Hoechst 33342荧光染色法荧光显微镜观察各浓度TFBP作用细胞48 h后的细胞的形态变化;通过免疫细胞化学SP法检测凋亡相关基因B细胞淋巴瘤/白血病2(Bcl-2),Bcl-2相关X蛋白(Bax)蛋白表达;比色法检测半胱氨酸蛋白酶-3(caspase-3)活性。结果:TFBP在体外对人肝癌细胞HepG-2有较强的浓度依赖性和时间依赖性抑制作用,9,12 g·L-1的TFBP作用HepG-2细胞72 h后,细胞增殖抑制率可分别达52.46%,64.72%,与对照组具有显著性差异(P<0.01),可诱导细胞凋亡,质量浓度9,12 g·L-1的TFBP作用HepG-2细胞48 h后就可出现典型的凋亡小体,TFBP可升高caspase-3活性,并具有浓度效应,同时还可下调Bcl-2蛋白表达,上调Bax蛋白表达,下调Bcl-2/Bax。结论:TFBP在体外对肝癌细胞HepG-2有明显的增殖抑制和诱导细胞凋亡的作用。其诱导凋亡的机制可能与其下调Bcl-2蛋白和上调Bax蛋白的表达,下调Bcl-2/Bax以及增强caspase-3的活性有关。     

Growth arrest and induction of apoptotic and non-apoptotic programmed cell death by, Physalis minima L. chloroform extract in human ovarian carcinoma Caov-3 cells

Ethnopharmacological relevance

The decoction of the whole plant of Physalis minima L. is traditionally consumed to treat cancer. Its anticancer property has been previously verified (using in vitro cytotoxicity assays) against NCI-H23 lung, CORL23 lung and MCF7 breast cancer cell lines but the mechanism underlying the anticancer potency towards ovarian carcinoma cells remain unclear.

Aim of the study

The present study is aimed to systematically determine the cytotoxicity and possible cell death mechanism elicited by the chloroform extract of Physalis minima in human ovarian Caov-3 carcinoma.

Materials and methods

Cytotoxicity of the extract was measured using the methylene blue assay. The mechanism of cell death was determined using four independent methods, namely DeadEnd™ assay to label the DNA fragmentation nuclei cells, RT-PCR analysis to determine the mRNA expression level of three apoptotic genes (c-myc, p53 and caspase-3 genes), Transmission Electron Microscope (TEM) analysis to describe the ultra structural characteristics and annexin V and propidium iodide staining to confirm the types and stages of cell deaths.

Results

Cytotoxicity screening of the extract on Caov-3 cells exhibited concentration- and time-dependent inhibitory effects. A combination of apoptotic and autophagic programmed cell death was detected. The apoptotic characteristic was initially determined by DNA fragmentation followed by the expression of c-myc and p53 genes that was much earlier than caspase-3. Apoptotic ultra structural changes (including clumping and magination of chromatin, blebbing and convolution of nucleus membrane and formation of apoptotic bodies) and autophagy (Type II non-apoptotic programmed cell death) with distinct vacuolated morphology were detected in TEM analysis. The existence of these programmed cell deaths was then corroborated using annexin V and propidium iodide staining.

Conclusions

The chloroform extract of Physalis minima exerted anticancer effect due to a combination of apoptotic and autophagic cell death mechanisms on Caov-3 cells. The induction of these programmed cell deaths was mediated via c-myc, p53 and caspase-3 dependent pathway. The results could provide a valuable insight in cancer therapy.     

Neurotrophic activity of DA-9801, a mixture extract of Dioscorea japonica Thunb. and Dioscorea nipponica Makino, in vitro

Ethnopharmacological relevance

Dioscorea japonica Thunb. has been traditionally used to treat polyuria and diabetes in Korea.

Aim of the study

We previously report the effects of Dioscorea japonica Thunb. extract on glucose control, NGF induction, and neuroprotection in a rodent diabetic model. Since the most potent fraction, DA-9801, was identified from a mixture of Dioscorea japonica Thunb. (DJ) and Dioscorea nipponica Makino (DN) following bioactivity-guided fractionation, here, we investigated the potential mechanism of the extract activity against diabetic peripheral neuropathy (DPN).

Materials and methods

A 1:3 mixture of DJ and DN was extracted with ethanol (DA-9801) and further fractionated into an ethylacetate-soluble fraction (DA-9801E). Effects of these extracts on neurite outgrowth were measured in PC-12 cells and DRG neurons. Effects on cell viability and TrkA phosphorylation were evaluated in PC-12 cells. NGF induction effect was determined in primary Schwann cells as well as IMS32 cells (immortalized Schwann cells).

Results

No cytotoxicity was observed in PC-12 cells at the concentration below 500 μg/ml of either DA-9801 or DA-9801E. DA-9801 and DA-9801E at 100 μg/ml and 10 μg/ml, respectively, showed a significant effect on neurite outgrowth in PC-12 cells and DRG neurons in the presence of or absence a low concentration of NGF (2 ng/ml). The Trk-A phosphorylation effect of DA9801 was confirmed in PC-12 cells. An NGF induction effect of these extracts was not detected in either IMS-32 cells, or primary Schwann cells.

Conclusions

The NGF agonistic activity of DA-9801 and DA-9801E was demonstrated, which may contribute to their neuroprotective effect against DPN. Studies of the detailed mechanism of these extracts as well as identification of the active components are warranted for the development of an anti-DPN drug from DJ and DN.     

雷公藤中倍半萜生物碱类化学成分的研究

目的 对雷公藤Tripterygium wilfordii乙醇提取物氯仿部位中的倍半萜生物碱类成分进行研究。方法 采用酸提碱沉法,结合中性氧化铝、十八烷基硅烷键合硅胶（ODS）及半制备高效液相等多种色谱技术进行分离纯化,并运用1D-NMR、2D-NMR、MS、ECD等波谱学方法对化合物进行结构鉴定。结果 从雷公藤乙醇提取物氯仿部位中分离得到5个倍半萜生物碱类成分,分别鉴定为(1S,4S,5R,6R,7R,8S,9S,10S)-1,8,11-triacetoxy-7-nicotinoyloxy-4,5-dihydroxy-dihydroagarofuran(1）、triptersinine U(2）、macroregeline F(3）、雷公藤宁碱B(4）和triptonine B(5）。结论 化合物1为新化合物,命名为雷公藤司宁Z15;化合物3为首次从该植物中分离得到。     

地黄提取物对人PC-3细胞凋亡机制的影响

目的:探讨熟地黄乙醇提取物对人前列腺癌PC-3细胞凋亡,初步探讨其作用的分子机制。方法:不同浓度(2.0、2.5、3.0、3.5 mg/mL)的熟地黄乙醇提取物作用于人前列腺癌PC-3细胞24 h、48 h后,采用噻唑蓝(Methyl Thiazolyl Tetrazolium,MTT)法检测熟地黄乙醇提取物对前列腺癌PC-3细胞分裂增殖的影响;Western-bloting法检测Livin、Survivin、Caspase3凋亡相关蛋白的表达。结果:抑制率具有浓度时间依赖性;熟地黄乙醇提取物能够影响PC-3细胞凋亡相关蛋白Livin、Survivin、Caspase3的表达。结论:熟地黄乙醇提取物抑制前列腺癌细胞增殖的机制可能与诱导前列腺癌细胞凋亡以及影响其凋亡相关蛋白的表达有关。     

多伞阿魏体外抗胃癌活性筛选、细胞凋亡及周期阻滞机制

目的:研究确定新疆特色维族药多伞阿魏体外抗胃癌活性部位及其敏感胃癌细胞系,并探讨多伞阿魏诱导胃癌细胞凋亡和细胞周期阻滞情况,为其进一步在抗胃癌方面的研究、开发与应用提供实验依据。方法:采用四甲基偶氮唑盐(MTT)比色法检测不同质量浓度多伞阿魏不同提取物(挥发油,95%乙醇提取物,及其石油醚部位,三氯甲烷部位,乙酸乙酯部位,正丁醇部位,水部位)分别对5种胃癌细胞系(AGS,MKN-45,BGC-823,MGC-803,SGC-7901)的增殖抑制作用;采用Hoechst33258荧光染色法观察多伞阿魏挥发油和三氯甲烷部位对胃癌细胞AGS和SGC-7901的影响情况;并应用细胞流式仪检测多伞阿魏不同提取部位作用胃癌细胞AGS和SGC-7901的凋亡和周期阻滞影响情况。结果:与空白组比较,多伞阿魏挥发油,95%乙醇提取物,石油醚部位,三氯甲烷部位,乙酸乙酯部位对5种胃癌细胞均有不同程度的增殖抑制作用(P0.05),并呈现浓度依赖关系。挥发油对胃癌细胞AGS呈现出较强的增殖抑制作用,其半数抑制浓度(IC50)为(7.98±2.62)mg·L~(-1),三氯甲烷部位对5种胃癌细胞系均具有较好的敏感性,对胃癌细胞SGC-7901最为敏感,其IC50为(8.73±0.55)mg·L~(-1),而正丁醇部位和水部位未呈现出明显的细胞增殖抑制作用;多伞阿魏挥发油和三氯甲烷部位作用胃癌细胞AGS和SGC-7901后,细胞核被Hoechst33258染色呈亮蓝色,且随着药物浓度的增加蓝色荧光越强;流式细胞凋亡检测结果显示,多伞阿魏不同提取部位诱导胃癌细胞AGS和SGC-7901发生不同程度的凋亡(P0.05),且随着药物浓度的增加,细胞总凋亡率明显增高;流式细胞周期检测结果显示,与空白组比较,多伞阿魏挥发油使胃癌细胞AGS的周期发生明显改变,细胞休眠期/DNA复制前期(G0/G1期)细胞比例增高,DNA复制期(S期)细胞比例降低,DNA复制后期/有丝分裂期(G2/M期)比例降低(P0.05);与空白组比较,多伞阿魏三氯甲烷部位使胃癌细胞SGC-7901的周期也发生显著改变,G0/G1期细胞比例降低,S期细胞比例增高,G2/M期比例降低(P0.05)。结论:多伞阿魏挥发油对胃癌细胞AGS呈现出较强的细胞毒活性,三氯甲烷部位对5种胃癌细胞均具有较好的增殖抑制作用,尤其对胃癌细胞SGC-7901最为敏感;多伞阿魏各提取部位诱导胃癌细胞AGS和SGC-7901主要发生晚期凋亡,而多伞阿魏乙酸乙酯部位诱导胃癌细胞AGS主要发生细胞早期凋亡;多伞阿魏挥发油能够将胃癌细胞AGS阻滞于G0/G1期,阻止细胞进入S期及G2/M期;伞阿魏三氯甲烷部位将胃癌SGC-7901细胞周期阻滞于S期。研究表明多伞阿魏挥发油和三氯甲烷部位具有较好的抗胃癌活性作用,具有潜在的研究价值和开发利用空间,并为多伞阿魏体内抗胃癌及其抗胃癌机制研究提供了一定的科学依据。     

紫草素诱导人前列腺癌PC-3细胞凋亡机制的探讨

目的:研究紫草素诱导人前列腺癌细胞(PC-3)凋亡及其作用机制。方法:以PC-3细胞为研究对象,以不同浓度的紫草素处理PC-3细胞,另设空白组,处理不同时间后,分别采用噻唑蓝(MTT)法检测紫草素对PC-3细胞增殖抑制情况;显微镜观察细胞形态变化;流式细胞仪检测细胞中活性氧(reactive oxygen species,ROS)的产生;蛋白质免疫印迹(Western blot)检测B细胞淋巴瘤/白血病-2(Bcl-2),Bcl-2相关X蛋白(Bax),半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)和磷酸化-细胞外信号调节激酶1/2(p-ERK1/2)蛋白的表达。结果:不同浓度的紫草素对PC-3细胞的生长抑制呈时间和剂量依赖性;形态学观察结果显示紫草素作用PC-3细胞后可使细胞变圆,脱落,皱缩,细胞内出现空泡,周围出现凋亡小体;与空白组比较,不同浓度的紫草素明显升高Caspase-3和Bax蛋白的表达,明显降低Bcl-2蛋白的表达,不同浓度的紫草素作用细胞48 h后可诱导细胞产生ROS,ROS清除剂二硫苏糖醇(DTT)可以明显逆转紫草素诱导的PC-3细胞的生长抑制率,且0.2 mmol·L-1DTT可以抑制由紫草素诱导的Caspase-3和ERK1/2的活化。结论:紫草素通过ROS/ERK1/2信号通路诱导人前列腺癌PC-3细胞发生凋亡。     

Matrine induces apoptosis in gastric carcinoma cells via alteration of Fas/FasL and activation of caspase-3

Aim of the study

Matrine, an alkaloid purified from the chinese herb Sophora flavescens Ait, is well known to possess activities including anti-inflammation, anti-fibrotic and anticancer. In this study, the mechanism of matrine inducing the apoptosis of gastric carcinoma cells was investigated.

Materials and Methods

Proliferation of SGC-7901 cells was examined by MTT assay. Cellular morphology was observed under transmission electron microscope. Flow cytometry (FCM) was used to observe the apoptosis of SGC-7901 cells by staining with annexinV-FITC/PI. The expression levels of Fas/FasL in SGC-7901 cells were monitored by FCM analysis using an indirect immunoflurenscence method. Activity of caspase-3 enzyme was measured by spectrofluorometry.

Results

MTT assay showed that matrine inhibited SGC-7901 cells proliferation in a dose-dependent and time-dependent manner. Apoptosis induction was demonstrated by morphological changes under electron microscope and FCM analysis. Florescence intensity levels of Fas and FasL were found to be equally up-regulated after matrine treatment, which were both correlated with apoptosis rate. The activity of caspase-3 enzyme increased in matrine groups, positively correlated with apoptosis rate.

Conclusions

Matrine could inhibit cell proliferation and induce apoptosis of SGC-7901 cells in vitro. The apoptosis induction appears to proceed by up-regulating Fas/FasL expression and activating caspase-3 enzyme.     

壁虎醇提物体外诱导人前列腺癌PC-3细胞凋亡及机制研究

目的:研究壁虎醇提物(GAE)体外诱导激素非依赖性前列腺癌PC-3细胞凋亡作用及其可能机制,为激素非依赖性前列腺癌的治疗提供理论依据。方法:以前列腺癌PC-3细胞为研究对象,MTT法检测3.5,4.0,4.5,5.0,5.5 g·L~(-1)GAE作用细胞24,48,72 h后对激素非依赖性前列腺癌PC-3细胞增殖抑制作用;3.5,4.0,5.0 g·L~(-1)的GAE作用48 h后,另设空白组,Hoeehst33342荧光染色法,Annexin V-FITC/PI双染流式细胞仪检测细胞凋亡,SP免疫组化法检测细胞内半胱氨酸蛋白酶3(Caspase 3)和Fas的表达情况并做统计学处理。结果:3.5,4.0,4.5,5.0,5.5 g·L~(-1)GAE作用细胞24,48,72 h后能显著抑制PC-3细胞的生长且呈剂量和时间依赖性;与空白组比较,3.5,4.0,5.0 g·L~(-1)的GAE作用48 h后Hoeehst33342荧光染色发现部分PC-3细胞发生典型的凋亡形态学改变;Annexin V-FITC/PI双染流式细胞仪检测显示3.5,4.0,5.0 g·L~(-1)的GAE作用48 h后,早期凋亡细胞分别占6.51%,12.48%和22.81%,且免疫组化显示细胞内蛋白Caspase-3和Fas的表达均上调且呈浓度依赖性(P0.05)。结论:GAE能够诱导激素非依赖性前列腺癌PC-3细胞凋亡,其作用机制可能与死亡受体介导的信号通路有关。     

Chemical composition and biological activity of a new type of Brazilian propolis: Red propolis

Propolis has been used as a medicinal agent to treat infections and promote wound healing for centuries. The aim of the present study was to test the antimicrobial, antioxidant, and cytotoxic activities of a new type of Brazilian propolis, popularly called red propolis, as well as to analyze its chemical composition. The antimicrobial activity against Staphylococcus aureus ATCC 25923 and Staphylococcus mutans UA159 was evaluated and the chloroform fraction (Chlo-fr) was the most active with lower MIC ranging from 25 to 50 μg/ml. The hexane fraction (H-fr), having the highest concentration of total flavonoids, showed the best sequestrating activity for the free radical DPPH. The ethanolic extract of propolis (EEP) showed cytotoxic activity for the HeLa tumor cells with an IC₅₀ of 7.45 μg/ml. When the EEP was analyzed by GC–MS, seven new compounds were found, among which four were isoflavones. Our results showed that the red propolis has biologically active compounds that had never been reported in other types of Brazilian propolis.