Novel anticancer alkene lactone from Persea americana

Abstract

Context: Persea americana Mill (Lauraceae) root bark is used in ethnomedicine for a variety of diseases including cancer.

Objective: To isolate and characterize the chemical constituent in P. americana, and also to determine the anticancer property of a new alkene lactone from the root bark of P. americana.

Materials and methods: The MCF-7 cells were treated with different concentrations of the pure compound for 48?h. The percentage of cells in the various phases, online monitoring of metabolic changes and integrin receptor expression determined by flow cytometry.

Results: One novel alkene lactone (4-hydroxy-5-methylene-3-undecyclidenedihydrofuran-2 (3H)-one) (1) was isolated and characterized using 1D-NMR, 2D-NMR, infrared, UV and MS. At a concentration of 10?µg/mL, significant reduction of proliferation of MCF-7 was induced while MCF-12?A cell was significantly stimulated by 10?µg/mL. The IC₅₀ value for MCF-7 cells is 20.48?µg/mL. Lower concentration of 1 harbor no significant effect on either MCF-7 or MCF-12A. The apoptotic rates of MCF-7 cells were increased significantly. At the final concentration 10?µg/mL, up to 80% of all breast cancer cells were dead. On the non-tumorigenic cell line MCF-12A, the same concentrations (1 and 10?µg/mL) of compound 1 caused significant enhanced apoptotic rates. A total of 1?µg/mL of 1 caused a decrease of α4-, α6-, β1- and β3-integrin expression.

Conclusions: The compound caused a stimulatory effect on non-tumorigenic MCF-12A cells with respect to cell adhesion while tumorigenic MCF-7 cells detached continuously. This is the first report on the anticancer effects of this class of compound.     

Osthole induces G2/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells

Context: Osthole [7-methoxy-8-(3-methyl-2-butenyl) coumarin] isolated from the fruit of Cnidium monnieri (L.) Cuss, one of the commonly used Chinese medicines listed in the Shennong’s Classic of Materia Medica in the Han Dynasty, had remarkable antiproliferative activity against human hepatocellular carcinoma HepG2 cells in culture.

Objectives: This study evaluated the effects of osthole on cell growth, nuclear morphology, cell cycle distribution, and expression of apoptosis-related proteins in HepG2 cells.

Materials and methods: Cytotoxic activity of osthole was determined by the MTT assay at various concentrations ranging from 0.004 to 1.0?µmol/ml in HepG2 cells. Cell morphology was assessed by Hoechst staining and fluorescence microscopy. Apoptosis and cell-cycle distribution was determined by annexin V staining and flow cytometry. Apoptotic protein levels were assessed by Western blot.

Results: Osthole exhibited significant inhibition of the survival of HepG2 cells and the half inhibitory concentration (IC₅₀) values were 0.186, 0.158 and 0.123?µmol/ml at 24, 48 and 72?h, respectively. Cells treated with osthole at concentrations of 0, 0.004, 0.02, 0.1 and 0.5?μmol/ml showed a statistically significant increase in the G2/M fraction accompanied by a decrease in the G0/G1 fraction. The increase of apoptosis induced by osthole was correlated with down-regulation expression of anti-apoptotic Bcl-2 protein and up-regulation expression of pro-apoptotic Bax and p53 proteins.

Conclusion: Osthole had significant growth inhibitory activity and the pro-apoptotic effect of osthole is mediated through the activation of caspases and mitochondria in HepG2 cells. Results suggest that osthole has promising therapeutic potential against hepatocellular carcinoma.     

Emodin inhibits ATP-induced IL-1β secretion,ROS production and phagocytosis attenuation in rat peritoneal macrophages via antagonizing P2X7 receptor

Context: Previous in vitro studies have demonstrated that emodin (1,3,8-trihydroxy-6-methyl-anthraquinone), an anthraquinone derivative from the rhizome of Rheum palmatum L., can inhibit the activation of P2X₇ receptors (P2X₇R) as a potential antagonist. However, the effects of emodin on P2X₇R-related inflammatory processes remain unclear.

Objective: This study aimed to investigate the effects of emodin on different inflammation responses of macrophages induced by ATP, the natural ligand of P2X₇R.

Materials and methods: Rat peritoneal macrophages were treated with millimolar ATP and emodin (0.1, 0.3,?1,?3,?10?µM) or brilliant blue G (BBG, 0.1,?1,?10?µM). Cytosolic Ca²⁺ concentration ([Ca²⁺]_c) was detected by fluorescent Ca²⁺ imaging. Interleukin-1β (IL-1β) release was measured by rat IL-1β ELISA kits. Reactive oxygen species (ROS) generation was examined by dihydroethidium (DHE) fluorescent staining. Phagocytic activity was tested by neutral red uptake assay.

Results: We found that the [Ca²⁺]_c increase evoked by ATP (5?mM) was inhibited by emodin, in a dose-dependent manner with IC₅₀ of 0.5?μM. Furthermore, emodin reduced the IL-1β release induced by ATP (2?mM) in lipopolysaccharide (LPS)-activated macrophages, with an IC₅₀ of 1.6?μM. Emodin also strongly suppressed the ROS production and phagocytosis attenuation triggered by ATP (1?mM), with IC₅₀ values of 1?μM and 0.7?μM, respectively. Besides, BBG, a specific antagonist of P2X₇R, exhibited similar suppressive effects on these inflammation responses.

Conclusion: These results showed the inhibitory effects of emodin on ATP-induced [Ca²⁺]_c increase, IL-1β release, ROS production and phagocytosis attenuation in rat peritoneal macrophages, by inhibiting the activation of P2X₇R.     

大黄素逆转肿瘤细胞多药抗药性的作用

目的：研究中药成分大黄素的核苷转运抑制活性和对肿瘤细胞多药抗药性的逆转作用。方法：采用［³H］-胸苷掺入法测定核苷转运抑制作用, 采用MTT法检测细胞毒作用, 采用流式细胞术测定P-糖蛋白的功能和表达。 结果：大黄素能抑制小鼠艾氏腹水癌细胞对［³H］-胸苷的跨膜转运,其IC₅₀为9.9　μmol.L^-1。大黄素能增强抗癌药物5-氟尿嘧啶、丝裂霉素和氨甲蝶呤对人肝癌BEL-7402细胞的细胞毒作用并能部分逆转人乳腺癌细胞MCF-7/Adr对阿霉素的抗药性。大黄素增加罗丹明123在MCF-7/Adr细胞中的蓄积并减少其外排,长时间作用降低了P-糖蛋白的表达。结论：大黄素逆转抗药性的作用与抑制核苷转运、降低P-糖蛋白的功能和表达相关。大黄素作为抗肿瘤生化调节剂用于逆转肿瘤细胞多药抗药性的作用值得进一步研究。     

Evaluation of the cytotoxicity,cell-cycle arrest,and apoptotic induction by Euphorbia hirta in MCF-7 breast cancer cells

Context: Euphorbia hirta L. (Euphorbiaceae) has been used as a folk remedy in Southeast Asia for the treatment of various ailments.

Objective: The current study evaluates the cytotoxicity, cell-cycle arrest, and apoptotic induction by E. hirta in MCF-7 breast cancer cells.

Materials and methods: Cytotoxic activity of methanol extract of whole part of E. hirta was determined by the MTT assay at various concentrations ranging from 1.96 to 250.00?µg/mL in MCF-7 cells. Cell morphology was assessed by light and fluorescence microscopy. Apoptosis and cell-cycle distribution were determined by annexin V staining and flow cytometry. DNA fragmentation, caspase activity, and reactive oxygen species (ROS) assays were performed using the commercially available kits. To identify the cytotoxic fraction, E. hirta extract was subjected to bioassay-guided fractionation.

Results: Euphorbia hirta exhibited significant inhibition of the survival of MCF-7 cells and the half inhibitory concentration (IC₅₀) values was 25.26?µg/mL at 24?h. Microscopic studies showed that E. hirta-treated cells exhibited marked morphological features characteristic of apoptosis. Euphorbia hirta extract also had an ignorable influence on the LDH leakage and generating intracellular ROS. The flow cytometry study confirmed that E. hirta extract induced apoptosis in MCF-7 cells. Euphorbia hirta also resulted in DNA fragmentation in MCF-7 cells. Moreover, E. hirta treatment resulted in the accumulation of cells at the S and G₂/M phases as well as apoptosis. The caspase activity study revealed that E. hirta extract induced apoptosis through the caspase-3-independent pathway by the activation of caspase-2, 6, 8, and 9. Euphorbia hirta hexane fraction, namely HFsub4 fraction, demonstrated highest activity among all the fractions tested with an IC₅₀ value of 10.01?µg/mL at 24?h.

Discussion and conclusion: This study revealed that E. hirta induced apoptotic cell death and suggests that E. hirta could be used as an apoptosis-inducing anticancer agent for breast cancer treatment with further detailed studies.     

Emodin elicits cytotoxicity in human lung adenocarcinoma A549 cells through inducing apoptosis

This study investigated the mechanism of the cytotoxic effect of emodin, an active anthraquinone, on human lung adenocarcinoma A549 cells. In vitro growth inhibition and suppression on colony forming were used to evaluate the effects of emodin on A549 cells. Emodin’s ability in changing the expressions of apoptosis-related genes was studied by real-time RT-PCR. Emodin could significantly inhibit the growth of A549 cells with IC₅₀ = 16.85 μg/ml (~60 μM). It also concentration dependently inhibited the colony-forming ability of A549 cells with IC₅₀ = 7.60 μg/ml (~30 μM). Hallmarks of apoptosis, such as single-strand DNA breakage and DNA fragmentation, were observed in A549 cells treated with emodin. Emodin (72 h) treatment could up-regulate the gene expression of FASL (p < 0.05) and down-regulate the gene expression of C-MYC (p < 0.01), but induce no significant changes in the gene expressions of MCL1, GAPDH, BAX and CCND1. These results suggest that emodin could induce growth inhibition and apoptosis in A549 cells through modifying the extrinsic apoptotic pathways and the induction of cell cycle arrest.     

Toxic effects induced by curcumin in human astrocytoma cell lines

Abstract

Objective: The objective of this study was to describe the toxicity induced by curcumin in human astrocytoma cell lines.

Methods: The effects induced by curcumin, at 100?µM for 24?h, were evaluated in four astrocytoma cell lines using crystal violet assay and through the evaluation of morphological and ultrastructural changes by electron microscopy. Also, the results of vital staining with acridine orange and propidium iodide for acidic vesicles and apoptotic bodies were analyzed and the expression of the Beclin1 gene was assessed by RT-PCR.

Results: The cells treated with curcumin at 100?µM induced an inhibitory concentration₅₀ of viability with morphological changes characterized by a progressive increase in large, non-acidic vesicles devoid of cytoplasmic components and organelles, but that conserved the cell nuclei. No DNA breakage was observed. The astrocytoma cells showed no apoptosis, necrosis or autophagy. Expression of BECLIN1 was not induced (p?<?0.05) by curcumin in the astrocytoma cells.

Conclusions: Curcumin at 100?µm induced a new type of death cell in astrocytoma cell lines.     

Effects of ginsenoside compound K combined with cisplatin on the proliferation,apoptosis and epithelial mesenchymal transition in MCF-7 cells of human breast cancer

Context: Breast cancer seriously harms the health of women and there are currently few therapeutic options for patients with breast cancer.

Objective: Effects of ginsenoside compound K (CK) in combination with cisplatin (DDP) on the proliferation, apoptosis, and epithelial mesenchymal transition (EMT) of MCF-7 cells were studied.

Materials and methods: MCF-7 cells were divided into CK (50?μmol/L) group, DDP (10?mg/L) group, CK (50?μmol/L)?+DDP (10?mg/L) group, and control (CON) group. The cells in the CON group were not treated with any drugs. Proliferation, apoptosis, expression of E-cadherin, N-cadherin, vimentin, protein kinase B (Akt), phosphorylated Akt (p-Akt), and level of fibronectin (FN) in MCF-7 cells were detected by methyl thiazolyl tetrazolium (MTT), flow cytometry, western blotting, and enzyme-linked immuno sorbent assay (ELISA), respectively.

Results: The proliferation inhibition rates in CK, DDP, and CK?+?DDP groups at 48?h were 19.18?±?2.25, 21.34?±?2.84, and 43.37?±?5.62, respectively. The apoptosis rates were 2.85?±?0.56, 13.37?±?2.28, 20.04?±?2.92, and 30.78?±?4.64 at 24?h and 3.14?±?0.72, 20.36?±?3.28, 27.58?±?4.09, and 41.62?±?5.83 at 48?h in CON, CK, DDP, and CK?+?DDP groups, respectively. CK or DDP alone and their combination all could reduce the levels of N-cadherin, vimentin, p-Akt/Akt, and FN and elevate level of E-cadherin.

Discussion and conclusion: Both CK and DDP can inhibit the proliferation, EMT, and induce the apoptosis in MCF-7 cells, which may be related to the PI3K/Akt pathway. In addition, the combination of CK with DDP can produce a better effect.     

AZT and emodin exhibit synergistic growth-inhibitory effects on K562/ADM cells by inducing S phase cell cycle arrest and suppressing MDR1 mRNA/p-gp protein expression

Abstract

Context: Previous studies have demonstrated that both 3′-azido-3′-deoxythymidine (AZT) and emodin, a traditional chemotherapy agent, can inhibit the growth of many types of cancer cells.

Objective: This study aimed to evaluate the effect of AZT and emodin on adriamycin-resistant human chronic myelogenous leukemia (K562/ADM) cells, determine the expression of multidrug resistance 1 (MDR1) mRNA/p-glycoprotein (p-gp) protein, a protein known to induce resistance to anticancer agents, and to elucidate the underlying molecular mechanisms.

Materials and methods: K562/ADM cells were treated with AZT (10–160?μM) or emodin (5–80?μM) for 24,?48 and 72?h and cell viability was measured using the MTT assay. The effect of AZT (16.5, 33 and 66?μM) and emodin (6.1,?17.6 and 33.2?μM) on K562/ADM cell cycle distribution was determined by flow cytometry, and MDR1 mRNA/p-gp protein expression was determined by real time RT-PCR and western blotting.

Results: The growth suppression of emodin was dramatically enhanced by AZT in K562/ADM cells. The IC₅₀ of AZT and emodin was lower than that of emodin alone. All examined combinations of AZT and emodin yielded a synergetic effect (CI?<?1). Furthermore, AZT and emodin altered the cell cycle distribution and led to an accumulation of cells in S phase. Meanwhile, the expression of MDR1 mRNA/p-gp protein was markedly decreased.

Discussion and conclusion: These results show a synergistic growth-inhibitory effect of AZT and emodin in K562/ADM cells, which is achieved through S phase arrest. MDR1 might ultimately be responsible for these phenomena.     

Effect of citral on the cytotoxicity of doxorubicin in human B-lymphoma cells

Abstract

Context: Doxorubicin is a chemotherapy agent used in non-Hodgkin's lymphoma but side effects limit its use. Citral is a mixture of neral and geranial found in essential oils of lemon grass.

Objectives: We evaluated the activity of citral, doxorubicin, and combination on cytotoxicity, apoptosis, and anti-proliferative effects using human lymphoma Ramos cells.

Materials and methods: Cells were treated with doxorubicin alone or in combination with citral (10, 20, and 40?μM). Cytotoxic and apoptosis studies were done after 24 and 18?h incubations, respectively. Cytotoxic effects of citral on normal human peripheral blood mononuclear cells (PBMCs) were also investigated for its safety. Changes in the expression of BCL-2 family genes were analyzed by quantitative RT-PCR.

Results: Citral had cytotoxicity on cells with an IC₅₀ value of 77.19?±?4.95?µM. Citral at concentrations of 10, 20, and 40?µM additively increased the cytotoxic and apoptotic effects of doxorubicin, leading to decreased IC₅₀ (µM) of the drug from 2.50?±?0.01 to 2.16?±?0.03, 1.90?±?0.04, and 1.23?±?0.04, respectively. Enhanced cytotoxicity was not observed in normal human PBMCs. Citral (40?µM) in combination with doxorubicin (1.5?µM) increased the expression of pro-apoptotic protein BAK but significantly decreased the expression of anti-apoptotic protein BCL-XL to 5.26-fold compared with doxorubicin-treated cells. It did not change the anti-proliferative activity of drug.

Discussion and conclusion: Citral potentiated cytotoxicity of doxorubicin by increasing apoptotic effects. We conclude that citral may have beneficial effects in patients with B cell lymphoma treated with chemotherapy.     

Isolation and identification of three new chromones from the leaves of Pimenta dioica with cytotoxic,oestrogenic and anti-oestrogenic effects

Context: Pimenta dioica (L.) Merr. (Myrtaceae) is used in Costa Rican traditional medicine for women’s health. Our previous work showed that P. dioica extracts were oestrogenic.

Objectives: This work identifies phytochemicals from P. dioica that are responsible for the plant’s oestrogen-like activities.

Materials and methods: P. dioica leaves were collected in Costa Rica in 2005. Fractions resulting from chromatographic separation of a methanol extract were tested at 50?μg/mL in a competitive oestrogen receptor-binding assay. Active compounds were isolated by HPLC and identified by NMR and MS. Pure compounds were tested at 1?μM in the oestrogen-responsive SEAP reporter gene assay. The effects on cell viability, cytotoxicity and apoptosis were investigated in breast cancer (MCF-7 and SK-BR3) and gastric cancer (AGS and NCI-N87) cell lines using the ApoTox-Glo and Caspase-Glo assays and qPCR.

Results: Quercitrin and three new chromones, including a 2-phenoxychromone, 6,8-di-C-methylcapillarisin (1) were isolated and identified. Compound 1 caused a 6.2-fold increase in SEAP expression at 1?μM (p?2 caused a 6.0-fold increase in SEAP, inhibited the growth of MCF-7, AGS and NCI-N87 cells (IC₅₀ 54.27, 38.13 and 51.22?μg/mL, respectively), and induced apoptosis via caspase 8 and increased the Bax/Bcl-2 mRNA ratio in MCF-7 cells. Compound 3 was anti-oestrogenic in MCF-7 cells.

Discussion and conclusions: Compounds from P. dioica have oestrogenic, anti-oestrogenic and cytotoxic effects that may explain the ethnomedical use of this plant.     

Schizandra chinensis extracts induce apoptosis in human gastric cancer cells via JNK/p38 MAPK activation and the ROS-mediated/mitochondria-dependent pathway

Abstract

Context: Schizandra chinensis Baill (Magnoliaceae) fruit extract (SCE) is considered a traditional herbal medicine for the treatment and alleviation of various diseases. Gastric cancer is the second most common cause of cancer-related death worldwide, and the first most common in Korea.

Objectives: This study investigates the mechanism of SCE-induced apoptosis in AGS human gastric cancer cells.

Materials and methods: SCE concentrations from 100 to 400?µg/ml were used. Cell viabilities were determined using MTT assay. Members of the Bcl-2 family and Bax were detected by Western blotting. RT-PCR was performed to measure the expression level of the Fas/FasL pro-apoptotic genes.

Results: SCE inhibited the proliferation AGS cells for 24 or 72?h (inhibition by 3.1%?±?5.2% at 100?µg/ml and 87.3%?±?7.6% at 400?µg/ml at 24?h and by 40.2%?±?5.3% 100?µg/ml and 95.3%?±?1.3% 400?µg/ml at 72?h) and increased the sub-G1 phase (25.3%?±?5.2% at 100?µg/ml and 370.2%?±?7.2% at 400?µg/ml) and the mitochondrial membrane depolarization (11.2%?±?2.1% at 100?µg/ml and 311.5%?±?6.1% at 400?µg/ml). The SCE-induced apoptotic cell death showed the down-regulation of Bcl-2, but up-regulation of Bax. Subsequently, SCE increased the expression level of Fas/FasL, activated caspase-9 and -3, and increased reactive oxygen species generation. Also, JNK II inhibitor or a p38 MAPK inhibitor inhibited SCE-induced cell death.

Discussion and conclusion: These results indicate that SCE might be an effective chemotherapeutic for the treatment of human gastric cancer.     

Dicranopteris linearis extract inhibits the proliferation of human breast cancer cell line (MDA-MB-231) via induction of S-phase arrest and apoptosis

Context: Dicranopteris linearis (Burm.f.) Underw. (Gleicheniaceae) has been scientifically proven to exert various pharmacological activities. Nevertheless, its anti-proliferative potential has not been extensively investigated.

Objective: To investigate the anti-proliferative potential of D. linearis leaves and determine possible mechanistic pathways.

Materials and methods: MTT assay was used to determine the cytotoxic effects of D. linearis methanol (MEDL) and petroleum ether (PEEDL) extracts at concentrations of 100, 50, 25, 12.5, 6.25 and 3.125?µg/mL against a panel of cancer cell lines (breast [MCF-7 and MDA-MB-231], cervical [HeLa], colon [HT-29], hepatocellular [HepG2] and lung [A549]), as compared to negative (untreated) and positive [5-fluorouracil (5-FU)-treated] control groups. Mouse fibroblast cells (3T3) were used as normal cells. The mode of cell death was examined using morphological analysis via acridine orange (AO) and propidium iodide (PI) double staining. Cell cycle arrest was determined using flow cytometer, followed by annexin V-PI apoptosis detection kit.

Results: MEDL demonstrated the most significant growth inhibition against MDA-MB-231 cells (IC₅₀ 22.4?µg/mL). PEEDL showed no cytotoxic effect. Induction of apoptosis by MEDL was evidenced via morphological analysis and acridine orange propidium iodide staining. MEDL could induce S phase cell cycle arrest after 72?h of incubation. Early apoptosis induction in MDA-MB-231 cells was confirmed by annexin V-FITC and PI staining. Significant increase in apoptotic cells were detected after 24?h of treatment with 15.07% cells underwent apoptosis, and the amount escalated to 18.24% with prolonged 48?h incubation.

Conclusions: MEDL has potential as a potent cytotoxic agent against MDA-MB-231 adenocarcinoma.     

Antiproliferative and apoptotic activities of extracts of Asclepias subulata

Abstract

Context: Asclepias subulata Decne. (Apocynaceae) is a shrub used in the Mexican traditional medicine for the treatment of cancer.

Objective: The objective of this study was to evaluate the antiproliferative activity of methanol extract of aerial parts of A. subulata and its fractions against different cancer cell lines. Additionally, we analyzed the mechanism of action of the active fractions.

Materials and methods: Methanol extract fractions were prepared by serial extraction with n-hexane, ethyl acetate, and ethanol. The antiproliferative activity of methanol extract and its fractions was evaluated, against several murine (M12.C3.F6, RAW 264.7, and L929) and human (HeLa, A549, PC-3, LS 180, and ARPE-19) cell lines by the MTT assay, using concentrations of 0.4–400?µg/mL for 48?h. Ethanol and residual fractions were separated using silica gel column. Apoptosis induction of cancer cells was evaluated by Annexin and JC-1 staining using flow cytometry.

Results: Methanol extract and its fractions showed antiproliferative activity against all human cancer cell lines tested. Methanol extract had the highest antiproliferative activity on A549 and HeLa cells (IC₅₀ values?<?0.4 and 8.7?µg/mL, respectively). Ethanol and residual fractions exerted significant antiproliferative effect on A549 (IC₅₀?<?0.4?µg/mL) and PC3 cells (IC₅₀ 1.4 and 5.1?µg/mL). Apoptotic assays showed that CEF7, CEF9, CRF6, and CRF5 fractions induced mitochondrial depolarization in A549 cells, 70, 73, 77, and 80%, respectively. Those fractions triggered the apoptosis mitochondrial pathway.

Conclusion: Our data show that A. subulata extracts have potent antiproliferative properties on human cancer cell lines. This plant should be considered an important source of potent anticancer compounds.     

The antitumour effects of eudesmin on lung cancer by inducing apoptosis via mitochondria-mediated pathway in the tumour cells

Context: Limonoids possess broad range of biological activities, including antitumour, antimicrobial and antioxidant activities, etc. Eudesmin (EDN) is a type of limonoid which also possesses various activities. However, there is no report on the antitumour lung cancer (LC) activities of this compound.

Objective: The present study investigates the antitumour effects of EDN and its potential molecular mechanisms.

Materials and methods: The in vitro antitumour effects of EDN on LC A549 cells were evaluated by using MTT assay. The in vivo antitumour effects were investigated on a xenograft athymic nude mouse model. The mice were administered orally with EDN (10, 20 and 40?mg/kg) once daily for 28 days. Effects of EDN on apoptosis-related or signalling proteins (Bcl-2, Bax, caspase-3, caspase-9, P53, Akt and JNK) were assayed by western blot analysis.

Results: EDN showed significant inhibitory effects on the growth of LC A549 cells in vitro with the half maximal inhibitory concentration (IC₅₀) of 18.3?μM. By treating with EDN (10, 20 and 40?μM), expression of caspase-3, caspase-9, Bax, P53 and phosphorylated JNK in A549 cells were significantly upregulated, whereas expression of Bcl-2 and Akt phosphorylation were significantly down-regulated. Interestingly, EDN-induced apoptosis could be attenuated by JNK inhibitor. In addition, in vivo experiments also indicated EDN (10, 20 and 40?mg/kg) had significant antitumour effects (p?Conclusions: Overall, the results indicated that EDN possesses significant antitumour effects on LC and the possible mechanism might be related to induction of mitochondria-mediated apoptosis.     

Antioxidant activity and cytotoxicity of Cyrtosperma johnstonii extracts on drug sensitive and resistant leukemia and small cell lung carcinoma cells

Context: The number of patients with cancer is increasing. New therapeutic agents to overcome drug-resistant tumors are urgently needed. Cyrtosperma johnstonii N.E. Br. (Araceae) is used for treatment of cancer in Thai traditional medicine. This study aimed to evaluate antioxidant activity and cytotoxicity of C. johnstonii extracts on human cancer cells.

Materials and methods: Dried powder of C. johnstonii rhizomes was extracted with several solvents. The 0.1?mg/ml extract solution was tested for antioxidant activity by 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric reducing antioxidant power (FRAP) assays. Color formation from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to determine cell viability. Standardization of the extract was performed by high-performance liquid chromatography (HPLC) with photodiode array detector at 254 and 360?nm. Cell cycle arrest was evaluated by flow cytometry after 5?min, 12?h and 24?h treated with 20 µg/ml of the acetone extract.

Results: The acetone extract exhibited the highest phenolic content and antioxidant activity (TEAC and EC values = 19.2?±?0.14 and 19.2?±?0.31?mM/mg, respectively). The IC₅₀ values for leukemia ranged from 11?±?1 to 29?±?3 µg/ml and from 5?±?2 to 6?±?0 µg/ml for small cell lung carcinoma cells. Cell cycle arrest occurred at the G2/M phase followed by apoptosis. HPLC analysis revealed that rutin is the major constituents of the extract.

Discussion and conclusion: The acetone extract of C. johnstoni is a promising source of natural antioxidants and anticancer. The extract inhibits cancer cells effectively with less effect on normal cells.     

Antiproliferative effects of extracts from Iranian Artemisia species on cancer cell lines

Objective: Different species of Artemisia (Asteraceae) have shown to exhibit antitumor activity. The aim of this study was to identify the antiproliferative effect of some Artemisia species from Iran on cultured human cancer cells.

Materials and methods: Methanol, ethyl acetate, dichloromethane and n-hexane extracts from aerial parts of seven species of Artemisia were prepared and their antiproliferative effects on four cancer (AGS, HeLa, HT-29 and MCF-7) and normal cell line (L929) were determined. Different concentrations of extracts were added to cultured cells and incubated for 72?h. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was employed to assess the cell viability.

Results: Different extracts exert various growth inhibitory effects. In case of AGS cells, dichloromethane and methanol extracts of A. ciniformis Krasch. & Popov ex Poljak. (IC₅₀ values: 35 and 60 µg/ml, respectively) showed the highest growth inhibitory effects. HeLa cells were more sensitive to both A. diffusa Krasch. ex Poljak. dichloromethane (IC₅₀ value: 71 µg/ml) and A. ciniformis ethylacetate (IC₅₀ value: 73 µg/ml) extracts. Dichloromethane extracts of A. diffusa, A. santolina Schrenk and A. ciniformis (IC₅₀ values: 42, 91 and 94 µg/ml, respectively) exhibited more inhibition on HT-29 cells in comparison to other extracts. MCF-7 cells were best inhibited by A. ciniformis dichloromethane (IC₅₀ value: 29 µg/ml) and A. vulgaris L. ethyl acetate (IC₅₀ value: 57 µg/ml) extracts.

Discussion and conclusion: This study shows the antiproliferative effects of Artemisia extracts on malignant cell lines. Artemisia could be also considered as a promising chemotherapeutic agent in cancer treatment.