Anticancer activity of isoobtusilactone A from Cinnamomum kotoense: involvement of apoptosis, cell-cycle dysregulation, mitochondria regulation, and reactive oxygen species

In this study, we investigate the anticancer effect of isoobtusilactone A (IOA), a constituent isolated from the leaves of Cinnamomum kotoense, on human non-small cell lung cancer (NSCLC) A549 cells. IOA was found to induce the arrest of G2-M phase, induce apoptosis, increase sub-G1, and inhibit the growth of these cells. Further investigation revealed that IOA's blockade of the cell cycle was associated with increased levels of p21/WAF1, p27 (kip1), and p53. In addition, IOA triggered the mitochondrial apoptotic pathway, as indicated by an increase in Bax/Bcl-2 ratios, resulting in a loss of mitochondrial membrane potential, release of cytochrome c, activation of caspase-9 and caspase-3, and cleavage of PARP. We also found the generation of reactive oxygen species (ROS) to be a critical mediator in IOA-induced inhibition of A549 cell growth. In antioxidant and NO inhibitor studies, we found that by pretreating A549 cells with either N-acetylcystenine (NAC), catalase, mannitol, dexamethasone, trolox, or L-NAME we could significantly decrease IOA production of ROS. Moreover, using NAC to block ROS, we could significantly suppress IOA-induced antiproliferation, antimigration, and anti-invasion. Finally, we found that IOA inhibited the migration and invasion of A549 cell migration and invasion. Taken together, these results suggest that IOA has anticancer effects on A549 cells.     

蜂毒素靶向PTEN/PI3K/Akt信号通路调控非小细胞肺癌细胞的增殖、凋亡

目的蜂毒素能否调控非小细胞肺癌细胞的增殖、凋亡,及其可能的作用机制。方法体外培养非小细胞肺癌细胞A549,在其中加入不同浓度蜂毒素进行干预(0、1、2、4 mg/L),MTT检测细胞增殖抑制率,Annexin V FITC/PI联合流式细胞仪检测细胞凋亡,Western Blot 检测细胞内PTEN、p-PI3K和p-Akt蛋白表达,RT-PCR检测细胞内p53和CyclinD1基因表达。结果蜂毒素能有效抑制A549细胞的增殖,促进细胞的凋亡,上调细胞PTEN的蛋白表达量,下调p-PI3K和p-Akt蛋白表达量,各浓度间差异具有统计学意义(P<0.05);蜂毒素能诱导p53 mRNA、抑制CyclinD1 mRNA的表达,各浓度间差异具有统计学意义(P<0.05)。结论蜂毒素能通过调控PTEN/PI3K/Akt信号通路抑制A549细胞的增殖,促进其凋亡。     

Anti‐lung Cancer Effects of Polyphyllin VI and VII Potentially Correlate with Apoptosis In Vitro and In Vivo

Polyphyllin VI (PVI) and polyphyllin VII (PVII) derived from Paris polyphylla possess anti‐cancer activities. However, the mechanisms for the anti‐lung cancer effects of PVI and PVII remain poorly understood. In this study, PVI and PVII exhibited inhibitory effects on the proliferation of A549 and NCI‐H1299 cells. PVI and PVII induced G2/M cell cycle arrest and triggered apoptosis. PVI and PVII upregulated the tumor suppressor protein p53 and downregulated cyclin B1. The two treatments significantly increased the expression levels of death receptor 3, death receptor 5, Fas, cleaved PARP, and cleaved caspase‐3. Furthermore, PVI and PVII significantly inhibited the growth of A549 cells in vivo. The tumor inhibitory rates of PVI were 25.74%, 34.62%, and 40.43% at 2, 3, and 4 mg/kg, respectively, and those of PVII were 25.63%, 41.71%, and 40.41% at 1, 2, and 3 mg/kg, respectively. Finally, PVI and PVII regulated the expression of proteins related to the apoptotic pathway in A549 xenografts. In summary, PVI and PVII exhibited strong inhibitory effects on lung cancer cell growth in vitro and in vivo by inducing G2/M cell cycle arrest and triggering apoptosis. Copyright © 2015 John Wiley & Sons, Ltd.     

黄芪水提物抑制PI3K/Akt通路预防肺癌发生的作用及机制研究

目的探讨黄芪水提物对肺癌的抑制作用及相关机制。方法采用MTT实验、Ed U实验以及划痕实验检测黄芪水提物对肺癌A549和H1299细胞的活性、增殖能力和迁移能力的影响,采用流式细胞仪考察黄芪水提物对肺癌细胞周期的影响,通过Western blotting实验检测PI3K/Akt通路相关蛋白表达,通过苯并芘诱导的小鼠肺癌模型观察黄芪水提物对体内肺癌的影响。结果 MTT实验结果表明,黄芪水提物作用于A549和H1299细胞48 h后,细胞的生长活性被抑制;Ed U实验结果表明,黄芪水提物能够显著抑制A549和H1299细胞的增殖能力;对细胞周期考察的实验结果表明,黄芪水提物能够将A549和H1299细胞周期阻滞在S期;划痕实验结果表明,黄芪水提物作用于A549和H1299细胞24 h和48 h后,能够显著抑制细胞的迁移能力;Western blotting实验结果表明,黄芪水提物能够下调A549和H1299细胞磷脂酰肌醇3激酶(PI3K)、磷酸化的磷酸肌醇依赖性蛋白激酶1(p-PDK1)和磷酸化的蛋白激酶B(p-Akt)蛋白表达水平;体内实验结果表明,黄芪水提物能够显著抑制小鼠肺部肿瘤数量及大小。结论黄芪水提物能够抑制肺癌,该机制可能与PI3K/Akt信号通路受阻有关。     

Growth inhibition of human lung cancer cells via down-regulation of epidermal growth factor receptor signaling by yuanhuadine, a daphnane diterpene from Daphne genkwa

The growth inhibition and antitumor activities of yuanhuadine (1), a daphnane diterpenoid from the flowers of Daphne genkwa, were investigated in human lung cancer cells. Compound 1 exhibited a relatively selective growth inhibition against human lung cancer cells compared to other solid human cancer cell lines. The potent antiproliferative activity by 1 was associated with cell-cycle arrest and modulation of cell-signaling pathways. Cell-cycle arrest in the G0/G1 and G2/M phase was induced by 1 in A549 human non-small-cell lung cancer cells, and these events were correlated with the expression of checkpoint proteins including the up-regulation of p21 and down-regulation of cyclins, cyclin-dependent kinases 2 (CDK2) and 4 (CDK4), and c-Myc. Compound 1 also suppressed the expression of the Akt/mammalian target of rapamycin (mTOR) and its downstream effector molecules including p70 S6 kinase (p70S6K) and eukaryotic initiation factor 4E-binding protein 1 (4EBP1). Ligand-induced epidermal growth factor receptor (EGFR) and c-Met signaling were also inhibited by 1. The oral administration of 1 (0.5 mg/kg body weight, daily) for 14 days significantly inhibited tumor growth in athymic xenograft nude mouse model bearing human lung A549 cells, without any overt toxicity. Synergistic antiproliferative effects of compound 1 were also found in combination with the EGFR inhibitor gefitinib. Cell-cycle arrest and suppression of Akt/mTOR and EGFR signaling pathways might be plausible mechanisms of actions for the antiproliferative and antitumor activity of 1 in human non-small-cell lung cancer cells.     

基于PAK6和Wnt/β-catenin信号通路的苦参碱对肺癌放疗敏感性的影响研究

目的 探究苦参碱对肺癌放疗敏感性的影响和作用机制.方法 人非小细胞肺癌A549细胞分为对照组、2 Gy放疗组、4 Gy放疗组、苦参碱组、苦参碱联合2 Gy组、苦参碱联合4 Gy组、甘氨双唑钠联合2 Gy组、甘氨双唑钠联合4 Gy组,通过克隆形成、细胞增殖、细胞凋亡评价苦参碱对A549细胞放疗敏感性的影响;建立裸鼠皮下移...     

c‐Jun N‐terminal Kinase‐Dependent Endoplasmic Reticulum Stress Pathway is Critically Involved in Arjunic Acid Induced Apoptosis in Non‐Small Cell Lung Cancer Cells

Though arjunic acid, a triterpene isolated from Terminalia arjuna, was known to have antioxidant, antiinflammatory, and cytotoxic effects, its underlying antitumor mechanism still remains unclear so far. Thus, in the present study, the molecular antitumor mechanism of arjunic acid was examined in A549 and H460 non‐small cell lung cancer (NSCLC) cells. Arjunic acid exerted cytotoxicity by 3‐[4, 5‐dimethylthiazol‐2‐yl]‐2, 5‐diphenyl tetrazolium bromide (MTT) assay and significantly increased sub‐G1 population in A549 and H460 cells by cell cycle analysis. Consistently, arjunic acid cleaved poly (ADP‐ribose) polymerase (PARP), activated Bax, and phosphorylation of c‐Jun N‐terminal kinases (JNK), and also attenuated the expression of pro‐caspase‐3 and Bcl‐2 in A549 and H460 cells. Furthermore, arjunic acid upregulated the expression of endoplasmic reticulum (ER) stress proteins such as IRE1 α, ATF4, p‐eIF2α, and C/EBP homologous protein (CHOP) in A549 and H460 cells. Conversely, CHOP depletion attenuated the increase of sub‐G1 population by arjunic acid, and also JNK inhibitor SP600125 blocked the cytotoxicity and upregulation of IRE1 α and CHOP induced by arjunic acid in A549 and H460 cells. Overall, our findings suggest that arjunic acid induces apoptosis in NSCLC cells via JNK mediated ER stress pathway as a potent chemotherapeutic agent for NSCLC.     

Activation of p53 signaling and inhibition of androgen receptor mediate tanshinone IIA induced G1 arrest in LNCaP prostate cancer cells

Our group previously reported that tanshinone IIA induced apoptosis via a mitochondria dependent pathway in LNCaP prostate cancer cells. In the present study, the roles of androgen receptor (AR) and p53 signaling pathways were investigated in tanshinone IIA-induced G1 arrest in LNCaP cells. Tanshinone IIA significantly inhibited the growth and proliferation of LNCaP cells by colony formation and BrdU incorporation assays, respectively. Tanshinone IIA induced cell cycle arrest at G1 phase and down-regulated cyclin D1, CDK2 and CDK4. Furthermore, tanshinone IIA activated the phosphorylation of p53 at Ser 15 residue and its downstream p21 and p27. Additionally, tanshinone IIA suppressed the expression of AR and prostate specific antigen (PSA). Conversely, silencing p53 using its specific siRNA reversed cyclin D1 expression inhibited by tanshinone IIA. However, knockdown of AR had no effect on the p53/p21/p27 signaling pathway activated by tanshinone IIA in LNCaP cells. In AR siRNA-transfected cells, tanshinone IIA did not cause cell cycle arrest and reduce cyclin D1, implying that AR is essential to induce G1 arrest by tanshinone IIA in LNCaP cells. Taken together, the findings suggest that tanshinone IIA induces G1 arrest via activation of p53 signaling and inhibition of AR in LNCaP cells.     

Apoptotic Effect of Galbanic Acid via Activation of Caspases and Inhibition of Mcl‐1 in H460 Non‐Small Lung Carcinoma Cells

Galbanic acid (GBA), a major compound of Ferula assafoetida, was known to have cytotoxic, anti‐angiogenic and apoptotic effects in prostate cancer and murine Lewis lung cancer cells; the underling apoptotic mechanism of GBA still remains unclear so far. Thus, in the present study, the apoptotic mechanism of GBA was investigated mainly in H460 non‐small cell lung carcinoma (NSCLC) cells because H460 cells were most susceptible to GBA than A549, PC‐9 and HCC827 NSCLC cells. Galbanic acid showed cytotoxicity in wild EGFR type H460 and A549 cells better than other mutant type PC‐9 and HCC827 NSCLC cells. Also, GBA significantly increased the number of Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells and sub G1 population in H460 cells. Western blotting revealed that GBA cleaved poly (ADP‐ribose) polymerase (PARP), activated Bax and caspase 9, attenuated the expression of Bcl‐2, Bcl‐x_L, and Myeloid cell leukemia 1 (Mcl‐1) in H460 cells. However, interestingly, overexpression of Mcl‐1 blocked the ability of GBA to exert cytotoxicity, activate caspase9 and Bax, cleave PARP, and increase sub G1 accumulation in H460 cells. Overall, these findings suggest that GBA induces apoptosis in H460 cells via caspase activation and Mcl‐1 inhibition in H460 cells as a potent anticancer agent for NSCLC treatment. Copyright © 2015 John Wiley & Sons, Ltd.     

麦冬皂苷B体外调控非小细胞肺癌A549细胞miRNA-34b表达的研究

目的：本研究主要观察不同方式处理后的非小细胞肺癌（NSCLC）A549细胞中miRNA?34b表达水平,探讨miRNA?34b对MET信号通路的调控机制,以及麦冬皂苷B（OPB）抑癌效应的分子机理,探寻治疗NSCLC的新靶点。方法：采用非小细胞肺癌A549细胞、胚肺成纤维细胞MRC?5、A549+OPB细胞、感染过表达慢病毒LV?hsa?mir?34b的A549细胞、以及感染阴性对照CON181B病毒的A549细胞作为研究对象,分别设为CON组、MRC?5组、CON+OPB组、Micro?up组、NC组。采用qRT?PCR方法检测miR?34b在CON组、MRC?5组、A549+OPB组A549细胞中的表达情况。使用生物信息学软件预测miRNA?34b可能的下游功能靶基因。使用qRT?PCR的方法定量分析OPB对MET基因表达的影响,用Western blot检测miRNA?34b和OPB对靶MET蛋白表达的影响。结果：与MRC?5组相比,A549细胞中miRNA?34b的表达明显减少,加入OPB后miR?34b的表达增加。生物信息学预测显示MET基因是miR?34b可能的关键下游靶基因。加入OPB后,MET基因水平和蛋白水平的表达均降低。结论：OPB可能通过上调A549细胞miRNA?34b表达,抑制下游靶基因MET进而发挥抗癌作用。     

消岩汤药物血清对A549/DDP多药耐药逆转作用的研究

[目的]探讨消岩汤药物血清对接种S180昆明小鼠肿瘤的抑制作用,及对耐顺铂人肺腺癌细胞系A549/耐顺铂(DDP)的耐药逆转作用。[方法]通过建立小鼠肿瘤模型,观察消岩汤对小鼠S180移植肿瘤生长的影响;以人肺腺癌敏感细胞A549和耐药细胞A549/DDP为研究对象,采用细胞毒实验(MTT)方法,探讨消岩汤对肺癌耐药细胞的多药耐药逆转作用。[结果]消岩汤高、低剂量组的抑瘤率分别是48.36%和27.87%;消岩汤荷瘤动物含药血清高、低剂量组分别与DDP合用时,对耐药细胞A549/DDP的杀伤作用分别是DDP组的1.78倍和1.57倍。[结论]消岩汤可改善小鼠生活质量,拮抗恶病质,并能够抑制肿瘤生长;消岩汤含药血清对A549及A549/DDP均有生长抑制作用,且能增强DDP对肺癌敏感细胞和耐药细胞的杀伤作用,具有耐药逆转作用。     

姜黄素对肺腺癌A549细胞增殖与凋亡的影响

目的：研究姜黄素对肺腺癌A549细胞增殖与凋亡的影响。方法：采用MTT法检测姜黄素对A549细胞存活率的影响。运用吖啶橙染色方法,观察细胞形态变化。利用TUNEL染色,检测DNA断裂情况。采用Western blot技术,检测P53蛋白表达变化。结果：姜黄素显著抑制A549细胞增殖。吖啶橙和TUNEL染色显示姜黄素可以诱导A549细胞凋亡。Western blot结果显示姜黄素提高了A549细胞中P53蛋白的表达。结论：姜黄素通过激活P53蛋白,抑制A549细胞增殖和诱导A549细胞凋亡。     

Eugenol inhibits non‐small cell lung cancer by repressing expression of NF‐κB‐regulated TRIM59

In view of the recognized anti‐tumor properties of eugenol against non‐small cell lung cancer (NSCLC) in cell culture, here we further set out to investigate the potential therapeutic effect of eugenol in vivo and elucidate the underlying molecular mechanism. The relative expression levels of TRIM59 and p65 in NSCLC were quantified by real‐time polymerase chain reaction. Xenograft tumor model was established with TRIM59‐deficient H1975 cells, and tumor progression was monitored. Kaplan–Meier's analysis was performed to measure overall survival. Protein levels of TRIM59 and p65 in xenograft tumor were determined by western blot. Direct binding of p65 on the TRIM59 promoter was analyzed by chromatin immunoprecipitation assay, and the regulatory effect was interrogated with luciferase reporter assay. Both TRIM59 and p65 were up‐regulated in NSCLC. Eugenol treatment significantly inhibited xenograft tumor progression and prolonged the overall survival of tumor‐bearing mice. Mechanistically, eugenol suppressed p65 expression, which subsequently decreased TRIM59 expression. TRIM59 deficiency fully recapitulated the anti‐tumoral phenotype elicited by eugenol. Ectopic expression of TRIM59 completely abolished the tumor suppressive effect of eugenol, which underlined the predominant role of TRIM59 in mediating the signaling downstream of eugenol treatment. Eugenol inhibited NSCLC via repression NF‐κB‐TRIM59 pathway.     

肺岩宁颗粒干预细胞周期G1/S检测点调控信号抗Lewis肺癌细胞增殖的研究

目的 观察肺岩宁颗粒对Lewis肺癌小鼠肿瘤生长、肿瘤细胞周期分布,以及G1/S检测点调控信号RB－E2F1生物轴的影响。 方法 采用C57BL/6小鼠,造模并随机分为6组：模型组、顺铂组、肺岩宁煎剂组（煎剂组）、肺岩宁颗粒低剂量组（低剂量组,0.3 g）、肺岩宁颗粒中剂量组（中剂量组,0.6 g）、肺岩宁颗粒高剂量组（高剂量组,1.2 g）。造模后顺铂组1、3、5天腹腔注射顺铂0.1 mg,其他各组分别灌胃给药14天,观察各组治疗后抑瘤率、瘤重、体重,流式细胞术检测细胞周期时相分布,RT-PCR测定肿瘤组织视网膜母细胞瘤蛋白（RB）－腺病毒E2启动子结合转录因子（E2F1）的mRNA表达,Western blot检测RB、E2F1蛋白表达。 结果 各用药组瘤重低于模型组（P<0.05,P<0.01）,中剂量组体重明显高于模型组和顺铂组（P<0.05,P<0.01）。流式细胞术发现中剂量组的G0/G1比例较模型组、顺铂组和煎剂组显著增多（P<0.01）,癌细胞增殖指数明显降低（P<0.01,P<0.05）。RT-PCR显示中剂量组E2F1 mRNA水平明显低于模型组、顺铂组和煎剂组(P<0.01);中剂量组RB mRNA表达明显高于模型组、顺铂组和煎剂组 (P<0.01)。Western blot分析显示中剂量组较模型组和顺铂组明显抑制E2F1蛋白表达(P<0.05),并较模型组、顺铂组和煎剂组明显增加RB蛋白表达(P<0.05)。 结论 肺岩宁颗粒抑制Lewis肺癌肿瘤生长与干预细胞周期时相分布有关,能使癌细胞较多的阻滞在细胞周期G0/G1期,通过抑制E2F1,增强RB表达,从而干预细胞周期G1/S检测点信号通路中RB－E2F1生物轴实现抗肺癌增殖。     

蝎毒多肽提取物对A549细胞增殖抑制作用机制研究

目的:观察蝎毒多肽提取物(PESV)对非小细胞肺癌细胞株A549的增殖抑制作用及可能的作用机制。方法:采用噻唑蓝(MTT)法观察不同浓度PESV对A549细胞生长与增殖的影响,下游实验将对数生长期的A549细胞分为阴性对照组、PESV低、中、高剂量组,应用流式细胞术、免疫细胞化学法、Western blot法检测PESV干预后细胞周期及VEGF,HIF-1α和PTEN蛋白表达的变化。结果:MTT结果显示,PESV在一定浓度范围内对A549细胞的增殖活性有明显抑制作用(P<0.01)。流式细胞法、免疫细胞化学法及Western blot法结果显示,PESV干预后能使A549细胞阻滞于G0/G1期,并显著下调HIF-1α,VEGF表达,上调PTEN表达。结论:PESV能够抑制A549细胞的增殖,其作用机制可能与影响血管生成因子VEGF,HIF-1α和PTEN的表达而直接抑制细胞增殖、阻滞细胞周期和抑制血管生成有关。     

Extracts from the roots of Lindera strychifolia induces apoptosis in lung cancer cells and prolongs survival of tumor-bearing mice

Lindera strychifolia, a scandent shrub Lauraceous medicinal plant, has been used in Chinese traditional medicine as a palliative and an anti-spasmodic. It also shows cytotoxic effects against several tumor cell lines and inhibits marcromolecule biosynthesis. This study investigated the anti-tumor effects of L. strychifolia extract against lung cancer cells using in vitro and in vivo models. Two human lung cancer cell lines A549 (adenocarcinoma) and SBC-3 (small cell carcinoma), and a non-tumor cell line 3T3-L1 (mice fibroblasts) were subjected to L. strychifolia extract treatment. On lung cancer cells, L. strychifolia induced cell growth inhibition in a dose-dependent manner. Conversely, the extract did not show any significant cytotoxic effect on 3T3-L1 cells. Therefore, the extract is specific for tumor cells. Tumor cells treated with L. strychifolia extract showed typical morphological appearance of apoptosis including nuclei fragmentation and cell condensation. The in vivo effects of L. strychifolia extract were investigated in C57BL/6 mice transplanted with Lewis lung cancer (LL-2) cells, and in BALB/c nude mice transplanted with A549 or SBC-3 human lung cancer cells. Oral administration of L. strychifolia extract prolonged survival time and inhibited tumor growth in a dose-dependent manner by inducing apoptosis in the LL-2 cell mice model. Furthermore, in A549 or SBC-3 cell nude mice models, oral administration of L. strychifolia extract also significantly inhibited tumor growth at the 5.0 mg/ml concentration. These findings suggested that the components of L. strychifolia have anticancer activity and may contribute to clinical applications in the prevention and treatment of lung cancer.     

灯盏花素对非小细胞肺癌A549细胞的作用及机制研究

目的:探讨灯盏花素(BVP)对非小细胞肺癌A549细胞增殖和细胞凋亡的影响。方法:将非小细胞肺癌A549细胞分为对照组、BVP低剂量组(20 μmol/L)、BVP中剂量组(40 μmol/L)、BVP高剂量组(80 μmol/L),使用噻唑蓝(MTT)比色法检测各组细胞12、24、48 h细胞存活率,使用AnnexinV-FITC /PI双染法检测各组细胞24 h细胞凋亡情况,使用蛋白印记法检测各组细胞细胞周期、凋亡相关蛋白表达。结果:BVP低、中、高剂量组A549细胞12、24、48 h时的细胞存活率依次呈降低趋势(P<0.05),作用相同时间时,BVP低、中、高剂量组A549细胞存活率均明显低于对照组(P<0.05),存在剂量效应(P<0.05); BVP低、中、高剂量组24 h细胞凋亡率和Ki67、增殖细胞核抗原(PCNA)、细胞周期蛋白D1(Cyclin D1)、B淋巴细胞瘤-2(Bcl-2)蛋白表达均明显低于对照组(P<0.05),而p21、Bcl-2相关X蛋白(Bax)、天冬氨酸蛋白水解酶-9(Caspase-9)、天冬氨酸蛋白水解酶-3(Caspase-3)蛋白表达量均明显高于对照组(P<0.05),存在剂量效应。结论:BVP可降低非小细胞肺癌A549细胞存活率和促进细胞凋亡,其机制可能与调节细胞增殖、凋亡相关蛋白表达有关。     

The extract of Hibiscus syriacus inducing apoptosis by activating p53 and AIF in human lung cancer cells

Natural products including plants, microorganisms and marine life provide rich resources for anticancer drug discovery. The root bark of Hibiscus syriacus has been used as an antipyretic, anthelmintic and antifungal agent in Asia. The antiproliferative effects of H. syriacus on human lung cancer cells were evaluated with bio-assays. The apoptotic activity was detected by Hoechst 33342 DNA staining and annexin V staining. The expression of caspases, p53, apoptosis induced factor (AIF), Bcl-2 and Bax were evaluated with Western blotting. The in vivo anticancer activity was evaluated using A549-xenograft model. The acetone extract of H. syriacus (HS-AE) exhibited a better cytotoxic effect on lung cancer cells than its methanol extract (HS-ME) or water extract (HS-WE). The IC(50) values of HS-AE on A549 (adenocarcinoma), H209 (squamous cell carcinoma) or H661 (large cell carcinoma) lung cancer cells ranged from 14 to 22 microg/ml after 48 hours of treatment. After 48 hours of exposure, HS-AE (15 microg/ml) induced A549 cell apoptosis to 48 +/- 3.6% of the control. Using Western blotting, HS-AE appears to suppress the expression of p53 and AIF. The results of the in vivo study showed that HS-AE suppresses growth in A549 subcutaneous xenograft tumors. These results indicate that HS-AE exerts significant and dose-dependent antiproliferative effects on cancer cells in vitro and in vivo, which prompts us to further evaluate and elucidate the bioactive component(s) of H. syriacus.