香烟烟雾提取物致小鼠生殖细胞的遗传学损伤及其机制

吸烟与许多疾病有关，但其对遗传或生殖损害研究报道尚少。香烟烟雾提取物可致小鼠生殖细胞染色体损伤，但该作用是否可能遗传给后代或影响生殖细胞的功能尚未见报道。香烟烟雾中含有许多自由基，而自由基可致DNA损伤。我们给雄性小鼠腹腔注射不同剂量香烟烟雾提取物，观察生殖细胞染色体     

羧甲司坦对香烟烟雾提取物诱导A549细胞炎性损伤的影响

目的：探讨羧甲司坦抑制香烟烟雾提取物（CSE）诱导A549细胞炎性损伤的作用。方法：传代培养人A549细胞并分为5组：对照组,CSE组,羧甲司坦低、中、高剂量组（予不同浓度羧甲司坦孵育和CSE诱导）。qRT-PCR、ELISA检测主要细胞因子的合成和释放,免疫蛋白印迹（Western-blot）、免疫荧光（IF）观察NF-κB及MAPK相关信号通路的活化情况。结果：以羧甲司坦预处理或后处理,均可降低CSE诱导的A549细胞的IL-6、IL-8和MIP-1β mRNA的表达;降低IL-6及IL-8的释放。羧甲司坦预处理可抑制p65入核。Western-blot结果显示,对照组,CSE组,羧甲司坦低、中、高剂量组的P-p65蛋白相对表达量分别为（0.17±0.05）、（0.90±0.19）、（0.68±0.15）、（0.64±0.12）和（0.57±0.13）,pERK1/2蛋白相对表达量分别为（0.30±0.10）、（1.25±0.33）、（1.01±0.19）、（0.89±0.22）和（0.81±0.18）,CSE组均明显高于对照组,羧甲司坦低、中、高剂量组均明显低于CSE组（P<0.05）。结论：羧甲司坦通过抑制NF-κB p65及ERK1/2 MAPK活化,发挥对CSE诱导的A549细胞炎性损伤的保护作用。     

香烟烟雾水溶性提取物对肝细胞线粒体的损伤

目的 探讨香烟烟雾水溶性提取物(CSW)对L-02肝细胞线粒体结构与功能的影响.方法 采用噻唑蓝(MTT)检测CSW处理L-02肝细胞24 h后的生存率,以确定后续试验CSW染毒浓度为0、8×10-3、16×10-3、32×10-3、64×10-3支/ml培养基.CSW染毒处理L-02肝细胞24 h后用MTF法检测线粒体总酶活力抑制率,荧光分光光度法检测线粒体膜通透性转运孔(PTP)开放度与细胞线粒体膜电位(△ψm)的变化,透射电子显微镜观察细胞线粒体形态学变化.结果 8×10-3、16×10-3、32×10-3、64×10-3支/ml 4个不同浓度处理组CSW对L-02肝细胞具有一定的细胞毒性,其细胞生存率随CSW处理浓度的增高而降低,且二者呈明显负相关(相关系数r=-0.957);线粒体PTP开放程度则随CSW浓度的增高而增加,32 ×10-3支/ml及其以上CSW浓度组开放度与对照组比较,差异有统计学意义(P＜0.05);线粒体总酶活力与细胞线粒体膜电位(△ψm)随CSW浓度的增加而下降,二者分别在8×10-3、16×10-3支/ml及其以上CSW浓度组与对照组比较,差异均有统计学意义(P＜0.05).透射电子显微镜观察线粒体形态发生显著改变即表现为肿胀、空泡变性、膜和嵴破损.结论 香烟烟雾水溶性提取物可对L-02肝细胞线粒体的结构与功能造成一定程度损伤.     

谷胱甘肽对香烟烟雾作用大鼠淋巴细胞氧化应激的影响

谷胱甘肽是由谷氨酸、半胱氨酸和甘氨酸组成的三肽类巯基物质,以2种形式存在:还原型(GSH)和氧化型(GSSG)。GSH与许多重要的生物学现象,如基因表达调控DNA生物合成、酶活力和代谢调节、免疫功能调节代谢等密切相关,作为细胞内重要的抗氧化剂和解毒剂,对保护细胞、延缓衰老有重要     

香烟烟雾对巨噬细胞的氧化损伤及盐酸氨溴索抗氧化作用的研究

目的研究香烟烟雾对体外培养的巨噬细胞的氧化损伤及盐酸氨溴索的抗氧化作用。方法采用黄嘌呤氧化酶法及硫代巴比妥酸法测定香烟烟雾提取物(CSE)和CSE+盐酸氨溴索作用于体外培养的小鼠巨噬细胞后30min、1、3和6h超氧化物歧化酶(SOD)和脂质过氧化物(LPO)的含量。结果加入CSE后3h,CSE组巨噬细胞SOD活性明显低于空白对照组,差异有统计学意义(P<0.05);CSE+氨溴索组SOD活性明显高于CSE组,差异有统计学意义(P<0.05);其余时间点三组SOD活性差异均无统计学意义。加入CSE后1h,CSE组巨噬细胞LPO含量明显高于空白对照组,差异有统计学意义(P<0.05);CSE+氨溴索组LPO含量与CSE组及空白对照组比较差异均无统计学意义;其余时间点三组LPO含量差异均无统计学意义。结论香烟烟雾作用于巨噬细胞产生脂质过氧化反应,造成氧化性损伤。盐酸氨溴索具有抗氧化作用,在一定程度上抑制过氧化反应,减轻氧化反应所致的损伤。     

黄芩苷调节细胞周期对缺氧神经细胞的保护作用研究

摘要：目的:观察黄芩苷（BL）对缺氧神经细胞的保护及细胞周期调节作用,并对其机制进行探讨。方法:以人神经母细胞瘤SK-N-SH细胞为研究模型并培养于正常环境（NE）中,三气培养箱构建缺氧环境（OGD）,设立NE组、OGD组及BL+OGD组。MTT法检测细胞活力,流式细胞术检测细胞周期和凋亡情况,蛋白印记实验检测P53、Cdc25a及Cyclin A蛋白表达变化。结果:与NE组相比,OGD组细胞活力明显降低（P<0.01）,5,10,25,50μmol·L-1BL处理24 h均能显著增强OGD组的细胞活力（P<0.01）,其中BL 25μmol·L-1浓度组作用最强。与NE组相比,OGD组细胞凋亡率和S期细胞比例明显升高（P<0.01）;而与OGD组相比,OGD+BL组（25μmol·L-1）细胞凋亡率和S期细胞比例明显降低（P<0.05或P<0.01）。与NE组相比,OGD组细胞P53蛋白表达明显上调（P<0.01）,Cdc25和Cyclin A蛋白表达明显下调（P<0.01）;而与OGD组相比,OGD+BL组细胞P53蛋白表达明显下调（P<0.01）,Cdc25和Cyclin A蛋白表达明显上调（P<0.01）。结论:BL对缺氧神经母细胞瘤SKN-SH细胞具有保护作用,该作用可能与其减缓细胞S期阻滞从而降低细胞凋亡有关。     

JNK信号转导通路在黄芩苷诱导肝癌细胞凋亡中的作用

目的探讨黄芩苷对人肝癌Hep G2细胞生长的抑制作用及其对c-Jun氨基末端激酶(JNK)信号通路的影响。方法 50、100、150μg/ml的黄芩苷分别与人肝癌Hep G2细胞共同培养24、48和72 h,MTT测定细胞生长抑制率;采用Western blotting方法检测黄芩苷处理72 h后Hep G2细胞JNK和p-JNK的表达变化并观察JNK抑制剂对细胞凋亡的影响。结果黄芩苷对人肝癌Hep G2细胞增殖抑制作用呈时间依赖性,黄芩苷浓度低于100μg/ml其对细胞的抑制作用随浓度升高而增强,超过100μg/ml其对细胞的抑制作用不再增强。在黄芩苷处理后Hep G2细胞pJNK蛋白表达上调,使用JNK抑制剂后,能阻断JNK蛋白的磷酸化,并且降低黄芩苷诱导细胞凋亡的能力。结论黄芩苷通过激活JNK信号通路诱导人肝癌Hep G2细胞凋亡。     

JNK 信号转导通路在黄芩苷诱导肝癌细胞凋亡中的作用

目的：探讨黄芩苷对人肝癌 HepG2细胞生长的抑制作用及其对 c-Jun 氨基末端激酶(JNK)信号通路的影响。方法50、100、150μg/ ml 的黄芩苷分别与人肝癌 HepG2细胞共同培养24、48和72 h,MTT 测定细胞生长抑制率;采用 Western blotting 方法检测黄芩苷处理72 h 后 HepG2细胞 JNK 和 p-JNK 的表达变化并观察 JNK 抑制剂对细胞凋亡的影响。结果黄芩苷对人肝癌 HepG2细胞增殖抑制作用呈时间依赖性,黄芩苷浓度低于100μg/ ml 其对细胞的抑制作用随浓度升高而增强,超过100μg/ ml 其对细胞的抑制作用不再增强。在黄芩苷处理后 HepG2细胞 p-JNK 蛋白表达上调,使用 JNK 抑制剂后,能阻断 JNK 蛋白的磷酸化,并且降低黄芩苷诱导细胞凋亡的能力。结论黄芩苷通过激活 JNK 信号通路诱导人肝癌 HepG2细胞凋亡。     

黄芩苷对羟自由基诱发心肌损伤的保护作用

目的:研究黄芩苷(baicalin,Bai)对羟自由基诱导大鼠心肌损伤的保护作用。方法:体外羟自由基发生系诱导心肌脂质过氧化,无机磷法测定心肌三磷酸腺苷(ATP)酶活性,分光光度法检测脂质过氧化物(MDA)含量、线粒体膨胀度和细胞色素氧化酶活性。结果:在羟自由基作用下心肌细胞膜中MDA含量明显升高,ATP酶活性显著降低,且ATP酶活性与MDA含量间呈显著负相关;线粒体膨胀明显,细胞色素氧化酶活性下降。Bai可降低保护羟自由基引起的心肌细胞膜MDA含量的升高和提高ATP酶活性;降低线粒体膨胀程度,恢复细胞色素氧化酶活性。结论:Bai可能通过清除氧自由基,抑制MDA的生成实现其保护心肌的功能。     

卷烟烟气中木犀草素和黄芩苷混合物对呼吸系统作用的研究

目的研究卷烟烟气中木犀草素和黄芩苷对呼吸系统的作用。方法将木犀草素和黄芩苷混合物加入卷烟制成特制卷烟,以动物吸烟机使混合物通过烟气接触动物呼吸系统。采用小鼠氨水引咳法制作咳嗽模型;以小鼠酚红排泄法评价气道分泌液量;以豚鼠整体动物药物引喘法评价对支气管痉挛的作用;并进行木犀草素和黄芩苷混合物经消化道给药和特制卷烟的急性毒性试验。结果与对照卷烟比较,特制卷烟可明显减少咳嗽,增加气道分泌液量,减轻动物呼吸道刺激。结论特制卷烟中木犀草素和黄芩苷能降低卷烟的呼吸系统危害性。     

Apoptotic effects of cigarette smoke extracts on mouse embryonic stem cells via oxidative stress

Previous studies have reported that cigarette smoke and cigarette smoke extract (CSE) have negative effects on embryonic development. However, no studies have investigated the mechanism through which CSE affects the cellular signaling pathway leading to apoptosis and oxidative stress in embryonic cells, or how the two pathways are cross‐linked. Thus, we studied the effects of CSE on apoptosis and oxidative stress in mouse embryonic stem cells (mESCs). Specifically, we measured changes in cell viability in response to CSEs (3R4F and two domestic cigarettes CSE 1 and 2) using a water soluble tetrazolium (WST) assay and a neutral red uptake (NRU) assay, which revealed that cell viability decreased in a concentration‐dependent manner. Western blot analysis revealed that the expression of cyclin D1 and cyclin E1 was decreased and that of p21 and p27 was increased by CSE. Additionally, the number of terminal deoxynucleotidyl transferase (TUNEL)‐stained cells was increased by CSE, while the levels of Bax and Caspase‐3 increased and Bcl‐2 decreased. Moreover, a 2′,7′‐dichlorofluorescin diacetate (DCF‐DA) assay and reactive oxygen species (ROS)‐Glo H₂O₂ assay confirmed that ROS were generated in response to CSE and that they were associated with up‐regulated Keaf‐1 and CHOP. Overall, the results revealed that cigarette smoke extract (CSE) inhibited cell proliferation by regulating cell cycle‐related protein expression and increased oxidative stress by regulating the expression of Kelch‐like ECH‐associated protein 1 (Keap‐1) and CCAAT/enhancer‐binding protein homologous protein (CHOP), resulting in apoptosis in mESCs.     

Cigarette Smoke Extract-induced Reduction in Migration and Contraction in Normal Human Bronchial Smooth Muscle Cells

The proliferation, migration, cytokine release, and contraction of airway smooth muscle cells are key events in the airway remodeling process that occur in lung disease such as asthma, chronic obstruction pulmonary disease, and cancer. These events can be modulated by a number of factors, including cigarette smoke extract (CSE). CSE-induced alterations in the viability, migration, and contractile abilities of normal human airway cells remain unclear. This study investigated the effect of CSE on cell viability, migration, tumor necrosis factor (TNF)-α secretion, and contraction in normal human bronchial smooth muscle cells (HBSMCs). Treatment of HBSMCs with 10% CSE induced cell death, and the death was accompanied by the generation of reactive oxygen species (ROS). CSE-induced cell death was reduced by N-acetyl-l-cysteine (NAC), an ROS scavenger. In addition, CSE reduced the migration ability of HBSMCs by 75%. The combination of NAC with CSE blocked the CSE-induced reduction of cell migration. However, CSE had no effect on TNF-α secretion and NF-κB activation. CSE induced an increase in intracellular Ca(2+) concentration in 64% of HBSMCs. CSE reduced the contractile ability of HBSMCs, and the ability was enhanced by NAC treatment. These results demonstrate that CSE treatment induces cell death and reduces migration and contraction by increasing ROS generation in normal HBSMCs. These results suggest that CSE may induce airway change through cell death and reduction in migration and contraction of normal HBSMCs.     

Effect of alpha lipoic acid on smoking-induced skin damage

Objective: Exposed to cigarette leads to the formation of reactive oxygen species and the generation of bioactive molecules that can damage skin cells. This investigation was carried out to study possible effects of Alpha Lipoic Acid (ALA) on smoking-induced rat skin injury.

Materials and methods: 28 Spraque–Dawley female rats were allocated into three groups: control group (n?=?8), smoking group (n?=?10; 12 cigarettes/day, 8 weeks) and smoking?+?ALA group (n?=?10; 12 cigarettes/day?+?100?mg/kg, 8 weeks). Experiment group animals were sacrificed under anaesthesia with 10%ketamine?+?2%xylasine at the end of second mounts and then skin examples were taken from the epigastric area. Histochemical (Haematoxylin–Eosin and Masson’s trichrome, immunohistochemical (TNF-α) and biochemical analysis (CAT, MDA and protein carbonylation) were performed on these skin tissues.

Results: Histologically, skin was distinguished normal structure in the control group. In the smoking group, collagen bundles and hair follicle degradation/reduction, sweat gland degeneration, mononuclear cell infiltration in dermis were encountered. In ALA-treated group, all of these changes were improved (p?<?0.05). Collagen bundles structures were appearance more regular than the smoking group . Immunohistologically, intense staining was observed in the smoking group, while very weak staining was observed in control group, weak staining was observed in the ALA-treated group. Biochemically; The CAT activity compared to cigarette group with control was raised high and in ALA group was higher compared to both groups, but not significant (p?>?0.05). MDA; which is indicator of lipid peroxidation was significantly higher in cigarette group than in control group (p?<?0.05) and was significantly lower in ALA group than cigarette (p?<?0.05). Protein carbonylation was higher in cigarette group than the control group but not in the non-significant (p?>?0.05). In the ALA it was significantly lower compared to the control group and cigarette (p?<?0.05).

Conclusions: Based on biochemical and histopathological determinations, the study showed that cigarette smoke can cause degenerative effects on skin tissues in rats. However, ALA has a curative effect on cigarette-induced injuries on the skin tissues by anti-oxidative and anti-inflammatory effects.     

Inhibition of immunological function mediated DNA damage of alveolar macrophages caused by cigarette smoke in mice

Exposure to cigarette smoke impairs the pulmonary immune system, including alveolar macrophage function, although the mechanisms by which this occurs are not fully elucidated. This study investigates the effect of cigarette smoke exposure on the antigen-presenting activity of alveolar macrophages, which is required for antigen-specific response to T cells. C57BL/6 mice were exposed to cigarette smoke for 10 days using a Hamburg II smoking machine, and alveolar macrophages were obtained by bronchoalveolar lavage. The antigen-presenting activity of alveolar macrophages was significantly inhibited in mice exposed to cigarette smoke compared with mice not exposed to cigarette smoke. Major histocompatibility complex class II cell surface molecule–positive cells, B7-1 molecule–positive cells, and interleukin-1β messenger RNA gene expression in alveolar macrophages were significantly decreased in mice exposed to cigarette smoke compared with mice not exposed to cigarette smoke. In contrast, DNA damage and generation of superoxide and hydrogen peroxide in alveolar macrophages were significantly increased by cigarette smoke exposure. These results suggest that inhibition of the antigen-presenting activity of alveolar macrophages may result from decreased expression of major histocompatibility complex class II and B7-1 molecules and interleukin-1β messenger RNA gene expression following cigarette smoke exposure. Furthermore, inhibition of antigen presentation in alveolar macrophage may result from DNA damage induced by excessive amounts of reactive oxygen species being generated by alveolar macrophages following cigarette smoke exposure. These findings suggest that cigarette smoke impairs the immunological function of alveolar macrophages and, as a result, increases the risk for pulmonary infection.     

Nicotine- and tar-free cigarette smoke induces cell damage through reactive oxygen species newly generated by PKC-dependent activation of NADPH oxidase

We examined cytotoxic effects of nicotine/tar-free cigarette smoke extract (CSE) on C6 glioma cells. The CSE induced plasma membrane damage (determined by lactate dehydrogenase leakage and propidium iodide uptake) and cell apoptosis {determined by MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] reduction activity and DNA fragmentation}. The cytotoxic activity decayed with a half-life of approximately 2 h at 37°C, and it was abolished by N-acetyl-l-cysteine and reduced glutathione. The membrane damage was prevented by catalase and edaravone (a scavenger of ^?OH) but not by superoxide dismutase, indicating involvement of ^?OH. In contrast, the CSE-induced cell apoptosis was resistant to edaravone and induced by authentic H₂O₂ or O₂^? generated by the xanthine/xanthine oxidase system, indicating involvement of H₂O₂ or O₂^? in cell apoptosis. Diphenyleneiodonium [NADPH oxidase (NOX) inhibitor] and bisindolylmaleimide I [BIS I, protein kinase C (PKC) inhibitor] abolished membrane damage, whereas they partially inhibited apoptosis. These results demonstrate that 1) a stable component(s) in the CSE activates PKC, which stimulates NOX to generate reactive oxygen species (ROS), causing membrane damage and apoptosis; 2) different ROS are responsible for membrane damage and apoptosis; and 3) part of the apoptosis is caused by oxidants independently of PKC and NOX.[Supplementary methods and Figure: available only at http://dx.doi.org/10.1254/jphs.11166FP]     

Oxidative stress is an important component of airway inflammation in mice exposed to cigarette smoke or lipopolysaccharide

1. It was proposed previously that oxidative stress is a main component of the inflammatory process in chronic obstructive pulmonary disease (COPD). Thus, in the present study, we investigated the inflammatory response in mice deficient for the p47(phox) subunit of NADPH oxidase (p47 KO) exposed to cigarette smoke (CS). 2. Exposure of mice to CS elicited an increase in the number of macrophages and neutrophils and levels of interleukin (IL)-6, keratinocyte-derived chemokine (KC/CXCL1) and monocyte chemoattractant protein-1 (MCP1/CCL2) in bronchoalveolar lavage fluid (BALF), which were lower in p47 KO mice compared with control mice. In contrast, 24 h after lipopolysaccharide (LPS) exposure, the number of macrophages and neutrophils, as well as KC/CXCL1 levels, in BALF was significantly greater in p47 KO mice compared with control mice. 3. The present study has shown that airway inflammation is decreased in p47 KO mice after exposure to CS, but not LPS, suggesting that oxidative stress is involved in the pathogenesis of airway inflammation associated with COPD.     

Induction of cell death by a novel naphthoquinone containing a modified anthracycline ring system

The novel naphthoquinone adduct 12,13-Dihydro-N-methyl-6,11,13-trioxo-5H-benzo[4,5]cyclohepta[1,2-b]naphthalen-5,12-imine (hereafter called TU100) was synthesized as a potential chemotherapeutic agent. TU100 arrests tissue culture cells in S and G2/M phases of the cell cycle, followed by rapid induction of apoptosis. Evaluation by the Developmental Therapeutics Program at the National Cancer Institute revealed TU100 differentially inhibits growth of tissue-specific human cancer cell lines and has in vivo efficacy in a hollow fiber assay. These data were evaluated against previously analyzed compounds using the COMPARE algorithm and predicted that TU100 has a unique mechanism of action. Further analysis revealed TU100 does not intercalate into DNA despite structural similarity to anthracyclines. Cells treated with the drug do exhibit DNA damage, however, as indicated by phosphorylation of histone H2A.X. This damage and effects on cell viability are likely mediated in part by TU100-induced reactive oxygen species. Based on these results, TU100 shows promise as a chemotherapeutic drug owing to its unique structure, cellular targets, and efficacy against selected panels of tissue-specific cancer cell lines.     

Cigarette smoke extracts induced the colon cancer migration via regulating epithelial mesenchymal transition and metastatic genes in human colon cancer cells

There was considerable evidence that exposure to cigarette smoke is associated with an increased risk for colon cancer. Nevertheless, the mechanism underlying the relationship between cigarette smoking and colon cancer remains unclear. Moreover, there were only a few studies on effects of complexing substance contained in cigarette smoke on colon cancer. Thus, we further investigated whether cigarette smoke extract (CSE) affects the cell cycle, apoptosis and migration of human metastatic colon cancer cells, SW‐620. MTT assay revealed that SW‐620 cell proliferation was significantly inhibited following treatments with all CSEs, 3R4F, and two‐domestic cigarettes, for 9 days in a concentration‐dependent manner. Moreover, CSE treatments decreased cyclin D1 and E1, and increased p21 and p27 proteins by Western blot analysis in SW‐620 cells. Additionally, the treatment of the cells with CSE contributed to these effects expressing by apoptosis‐related proteins. An increased migration or invasion ability of SW‐620 cells following CSE treatment was also confirmed by a scratch or fibronectin invasion assay in vitro. In addition, the protein levels of E‐cadherin as an epithelial maker were down‐regulated, while the mesenchymal markers, N‐cadherin, snail, and slug, were up‐regulated in a time‐dependent manner. A metastatic marker, cathepsin D, was also down‐regulated by CSE treatment. Taken together, these results indicate that CSE exposure in colon cancer cells may deregulate the cell growth by altering the expression of cell cycle‐related proteins and pro‐apoptotic protein, and stimulate cell metastatic ability by altering epithelial‐mesenchymal transition (EMT) markers and cathepsin D expression. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 690–704, 2017.     

Physicochemical Properties of Liposomes Affecting Apoptosis Induced by Cationic Liposomes in Macrophages

Purpose. Cationic liposomes are expected to be useful as nonviral vectors for gene delivery. Cationic liposomes showed cytotoxicity, and we proposed that the cytotoxicity is through apoptosis. In this study, we examined the effects of liposomal properties, such as liposomal charge, size, membrane fluidity, and PEG coating, on the induction of apoptosis in the macrophage-like cell line RAW264.7. Methods. RAW264.7 cells were treated with liposomes, and the induction of apoptosis was evaluated by monitoring the changes in DNA content by flow cytometry. The association of liposomes with cells and the generation of reactive oxygen species (ROS) were also measured by flow cytometry. Results. The induction of apoptosis of RAW264.7 cells was dependent on the concentrations of stearylamine or cholesterol, a component of cationic liposomes. A significant correlation was observed between the degree of apoptosis and association of cationic liposomes with the cells. Coating the liposomal surface with polyethylene glycol (PEG) decreased the association of cationic liposomes with RAW264.7 cells and reduced the induction of apoptosis. Liposomal size also affected the induction of apoptosis, and larger liposomes showed a higher degree of apoptosis induction. Furthermore, ROS, which were required for the induction of apoptosis by cationic liposomes, were generated in a cholesterol content-dependent manner, and ROS generation was also decreased by PEG coating as the association and the induction of apoptosis were reduced. Conclusions. The degree of apoptosis is related to the extent of association of cationic liposomes with cells and is related to the generation of ROS.