Anticancer activity of 28-Oxoallobetulin on HT-29 human colon cancer cells

Many successful therapeutic drug, including several anticancer agents, have been isolated for natural products. In a recent screen of methanolic extracts from several natural products, we isolated an active compound, from the methanolic extract of persimmon calyx, which promoted cytotoxicity and apoptosis in HT-29 human colon cancer cells. This compound was identified as 28-oxoallobetulin, a prototypical compound, by UV-MS analysis and various NMR spectroscopic methods. The highly cytotoxic effects of 28-oxoallobetulin on HT-29 cells were demonstrated using MTT reduction, LDH release, and colony formation assays. Furthermore, we were able to detect apoptotic bodies in HT-29 cells by Hoechst staining as well as flow cytometric analysis for the presence of sub-G1 DNA peaks, indicative of apoptotic cells. Finally apoptosis in HT-29 cells following 28-oxoallobetulin treatment was also confirmed by the presence of activated caspase-3 and specific proteolytic cleavage of poly (ADP-ribose) polymerase.     

Selective cytotoxicity of Saururus chinensis in glucose-deprived HT-29 human colon cancer cells

In this study, the selective cytotoxic activity of methanolic extracts of Saururus chinensis (SCE) was examined on glucose-deprived HT-29 cells. The effects of SCE on 2-deoxy-glucose (2DG) or glucose-free stressed HT-29 cells were evaluated through the MTT reduction assay, morphological observations, and the colony formation assay, in which SCE (5, 10 μg/mL) was found to be highly toxic to HT-29 cells only during glucose-deprived conditions. In addition, the mechanism of selective cytotoxic effects on SCE was assessed by Western blot analysis; SCE suppressed the accumulation of GRP78. Furthermore, apoptotic effects of SCE on glucose-deprived HT-29 cells were identified by Hoechst 33342 staining and flow cytometric analysis. In conclusion, SCE induced apoptosis in HT-29 cells under glucose-deprived conditions by down-regulation of GRP78. Cytotoxic effects on HT-29 cells were only observed during glucose deprivation, suggesting that SCE may be a target for novel therapeutic agents for treating colon cancer under glucose-deprived stress.     

下关生沱茶的HT-29人体结肠癌细胞的体外抗癌效果

对2005年,2007年和2009年产下关生沱茶,进行HT-29结肠癌细胞体外抗癌效果评价,通过MTT试验、细胞生长率试验和RT-PCR分析验证其抗癌效果。200μg／mL质量浓度下2005年产下关生沱茶（85％）表现出对HT-29结肠癌细胞最强的生长抑制效果。RT—PCR检查Bax,Bcl-2基因表达情况显示2005年产下关生沱茶对HT-29结肠癌细胞有最强的诱其凋亡的能力。由此得出,储存时间越长的沱茶具有更好的抗癌预防效果。     

Antioxidant activity versus cytotoxic and nuclear factor kappa B regulatory activities on HT-29 cells by natural fruit juices

The antioxidant activity (free radical scavenging ability and lipid oxidation inhibitory activity) and the activity in cell culture [influence on HT-29 human colon cancer cell viability and nuclear factor kappa B (NF-κB) activation] of natural fruit juices from red grape, strawberry, cherry and sour cherry were investigated in vitro. Analysis of polyphenolic composition of fruit juices showed the dominant presence of anthocyanins (cyanidin-3-glucoside, cyanidin-3-rutinoside, peonidin-3-rutinoside, pelargonidin-3-glucoside), anthocyanidins (procyanidins B1, B2 and B3), flavonoids (glucosides of myricetin, quercetin and kaempferol), and phenolic acids (neochlorogenic acid, chlorogenic acid, ellagic acid, p-coumaroylquinic acid) in juices. DPPH test and β-carotene bleaching method indicated that grape, strawberry, cherry and sour cherry natural juices (at the concentration of 2.5%) showed very strong free radical scavenging (75–92%) and antioxidant activity (71–94%). In addition, at the concentration of 0.01% they showed complete inhibition of copper-induced oxidation of human LDL (low density lipoprotein). In contrast, selected fruit juices did not show cytotoxic effects on HT-29 cells and NF-κB inhibitory activity (at the concentrations of 0.5 and 2%). Results of this study showed no correlation between the antioxidant activity of natural fruit juices from red grape, strawberry, cherry and sour cherry and their effect on HT-29 cell viability and NF-κB inhibitory activity.     

Antioxidant and antiproliferative activities of grape seeds from different cultivars

Grape seeds contain high levels of phytochemicals, which have been correlated with a decreased risk of chronic diseases. In this study, grape seeds from 10 different cultivars (‘SV 18315’, ‘Naples’, ‘Agawam’, ‘Aligote’, ‘V.50151’, ‘Cabernet Sauvignon’, ‘Urbana’, ‘Baco22A’, ‘Clinton’, and ‘Campbell Early’) were evaluated for their antioxidant and antiproliferative activities. The antioxidant activity of the grape seeds was evaluated by radical scavenging activities and reducing power. The antiproliferative activity was assessed by the inhibition of MCF7, NCI-H460, HCT116, and MKN45 cancer cell proliferation. The total polyphenol and flavonoid contents were determined by spectrophotometric methods. ‘Cabernet Sauvignon’ and ‘Baco22A’ had high polyphenol (4,369.2 and 3,747.0 mg/100 g seeds) and flavonoid contents (3,072.7 and 2,032.9 mg/100 g seeds). ‘Cabernet Sauvignon’ and ‘Baco22A’ also possessed the highest radical scavenging activity. In addition, these were showed generally higher antiproliferative activity than other cultivars. Both the polyphenol and flavonoid contents were positively correlated with radical scavenging activity (R²>0.9). These results may provide basic information about health-beneficial effects of grape seeds.     

苹果皮果胶多糖的理化性质以及抑制人结肠癌细胞HT-29增殖活性的初步研究

用水、质量分数0.5%草酸铵溶液、0.05 mol/L HCl溶液、1 mol/L KOH溶液从苹果皮中提取得到4种果胶多糖,分别是水溶性果胶多糖(WSP)、盐溶性果胶多糖(CSP)、酸溶性果胶多糖(ASP)和碱溶性果胶多糖(BSP)。测定了它们的总糖、糖醛酸和蛋白含量以及相对分子质量、单糖组成及摩尔比和红外光谱;并初步研究了4种苹果皮果胶多糖对人结肠腺癌细胞系HT-29细胞生长的抑制作用。结果显示:WSP、CSP、ASP和BSP的相对分子质量均大于4.0×105Da;气相色谱测定WSP、CSP、ASP和BSP的单糖组成及摩尔比,4种果胶多糖均含有半乳糖,而CSP所含的半乳糖醛酸含量最多,BSP不含半乳糖醛酸。WSP、CSP、ASP和BSP都能抑制人结肠腺癌细胞系HT-29细胞的增值,CSP的抑制活性最高(35.65%),BSP的抑制活性最低(10.30%),初步分析可能与苹果皮果胶多糖中半乳糖及半乳糖醛酸残基的含量相关。     

Erythrodiol, a natural triterpenoid from olives, has antiproliferative and apoptotic activity in HT-29 human adenocarcinoma cells

Erythrodiol is the precursor of pentacyclic triterpenic acids present in Olea Europaea. Although olive oil and some of its constituents are reported to have anticarcinogenic activities, erythrodiol has not been assessed in its cell biological functions in detail. We therefore determined its effects on cell growth and apoptosis in human colorectal carcinoma HT-29 cells. Proliferation, cytotoxicity, and apoptosis were measured by fluorescence-based techniques. Erythrodiol inhibited cell growth with an EC50 value of 48.8 +/- 3.7 microM without any cytotoxic effects in a concentration range up to 100 microM. However, exposure of cells for 24 h to 50, 100, and 150 microM erythrodiol increased caspase-3-like activity by 3.2-, 4.8-, and 5.2-fold over that in control cells. We here demonstrate for the first time that, in colon adenocarcinoma cells, erythrodiol exerts antiproliferative and proapoptotic activity.     

Antioxidant peptides isolated from sea cucumber Stichopus Japonicus

The sea cucumber Stichopus japonicus protein was hydrolyzed by pepsin, trypsin, papain, acid protease and neutral protease, respectively, to get five kinds of peptide fractions: pepsin peptides (PP), trypsin peptides (TP), acid protease peptides (AP), neutral protease peptides (NP) and papain peptide (PAP). Antioxidative activities of all peptide fractions were evaluated by hydroxyl radical– (·OH) and Superoxide anion (O₂ ^{· −} )–scavenging activity. Trypsin peptide (TP) exhibited the highest antioxidative activity compared to other peptide fractions. In considering scavenging effects on hydroxyl radicals (·OH) and Superoxide anions (O₂ ^{· −} ), TP was employed for isolation, purification and identification of antioxidant peptide. To purify and characterize antioxidative peptide, two steps gel filtration, one-step ion-exchange column chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC) were used. The purified antioxidative peptide TP2b-1 was a novel peptide and was sequenced as GPEPTGPTGAPQWLR, in which the low molecular weight and some amino acid constituents played important role in the radical-scavenging effects according reports. The IC₅₀ values of TP2b-1 were 138.9 μM on ·OH and 353.9 μM on O₂ ^{· −} .     

Bean (Phaseolus vulgaris L.) polysaccharides modulate gene expression in human colon cancer cells (HT-29)

Colorectal cancer is one of the most commonly diagnosed cancers in the United States and the third cause of cancer mortality in México. We present the results of molecular changes involved in p53 pathway in HT-29 cells evaluated by PCR array after 24 h exposure to in vitro fermented bean (cv. Bayo Madero) polysaccharide extract with human gut flora (FE-hgf). Significant differences were detected in 72 of 84 human p53-mediated signal transduction response genes involved in apoptosis, cell cycle and cell proliferation showed significant expression changes. Apoptosis genes, SIAH1, PRKCA and negative regulation of the cell cycle gene MSH2 were the highest up-regulated genes (30.5-, 18.4- and 9.8-fold, respectively), whereas cell cycle genes CHEK1 and GADD45A were markedly down regulated (21.4- and 9.1-fold, respectively). We demonstrate that common beans and or/it´s polysaccharides modulate gene expression profiles in HT-29 cells, providing insight about the mechanism underlying its overall chemoprotective function against colon carcinogenesis.     

Antioxidant and antigenotoxic effects of plant cell wall hydroxycinnamic acids in cultured HT-29 cells

We demonstrate that two hydroxycinnamic acids, (E )-ferulic acid and (E )-p-coumaric acid, have the ability to protect against oxidative stress and genotoxicity in cultured mammalian cells. They also show the ability to reduce the activity of the xenobiotic metabolising enzyme, cytochrome P450 1A, and downregulate the expression of the cyclooxygenase-2 enzyme. At equitoxic doses, their activities are equal to or superior to that of the known anticarcinogen, curcumin. The hydroxycinnamic acids are both important components of plant cell walls in certain plant foods. It is known that the action of microbial hydroxycinnamoyl esterases can lead to the release of hydroxycinnamic acids from ester-linkages to cell wall polysaccharides into the human colon. Thus, providing they can reach effective levels in the colon, they could provide an important mechanism by which dietary fibres of food plants, such as spinach or cereal, protect against colon cancer.     

金钗石斛脂溶性生物碱提取物诱导人结肠癌 HT-29 细胞凋亡

目的:研究金钗石斛脂溶性生物碱提取物对人结肠癌HT-29细胞生长的抑制作用及其诱导细胞凋亡的分子机制。方法:MTT法检测金钗石斛脂溶性生物碱提取物对HT-29细胞存活率的影响,Hoechst33342染色法观察细胞形态学变化,流式细胞仪检测胞内活性氧水平、线粒体膜电位、细胞周期和细胞凋亡率变化;蛋白免疫印迹检法测蛋白Caspase-3,9和胞内细胞色素C的表达。结果:金钗石斛脂溶性生物碱提取物能降低HT-29结肠癌细胞存活率,呈剂量和时间效应,48 h半数抑制浓度（IC50）为0.72 mg/m L;金钗石斛脂溶性生物碱提取物能诱导HT-29细胞凋亡,并诱导细胞周期阻滞于G2期;金钗石斛脂溶性生物碱提取物诱使线粒体膜电位降低,胞内活性氧浓度升高;激活型Caspase-9,3与胞内细胞色素C表达水平增高。结论:金钗石斛脂溶性生物碱提取物对HT-29结肠癌细胞的生长具有抑制作用并诱导细胞凋亡,其可能通过线粒体凋亡途径诱导细胞凋亡。      

葡萄籽多酚化合物抗氧化能力与抗癌细胞增殖活性的评价

目的:探讨葡萄鲜果及酿酒皮渣中葡萄籽提取物中的酚类化合物含量,抗氧化特性及对癌细胞增殖的抑制作用。方法:乙醇法提取葡萄籽中多酚化合物,分光光度计法测定三大酚类化合物参数(总酚、类黄酮类、黄烷-3-醇类)及3种抗氧化性能参数(DPPH及ABTS自由基清除能力,FRAP分析)。体外培养肝癌细胞HepG2,建立细胞模型,不同浓度的提取物作用于癌细胞后,采用四甲基偶氮唑盐比色法(MTT法)检测多酚提取物对癌细胞增殖的抑制作用。结果:不同样品葡萄籽所含酚类化合物、抗氧化性能、抗癌细胞增殖能力均不同,酿酒皮渣的葡萄籽中仍含有大量的多酚化合物,其中欧亚种赤霞珠鲜果及酿酒皮渣中葡萄籽所含酚类化合物、抗氧化能力及抗癌细胞增殖活性高于圆叶葡萄Noble鲜果及酿酒皮渣。结论:葡萄鲜果与酿酒皮渣中的葡萄籽多酚化合物具有抗氧化能力及抗癌细胞增殖活性。     

抑制人结肠癌HT-29细胞增殖乳酸菌有效成分的筛选

以鼠李糖乳杆菌（Lactobacillus rhamnosus）GG（LGG）为阳性对照,4株具有潜在抗结肠癌功效的乳酸菌为研究对象,提取其细胞壁及细胞质,通过3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐（MTT）法初步筛选具备抑制HT-29细胞增殖能力的成分,再通过分析提取成分对HT-29细胞DNA损伤、细胞死亡及周期的影响,获得具有抗结肠癌作用的有效成分。结果表明,与阳性对照LGG相比,乳酸菌X11、X12、M5、K14的细胞壁和乳酸菌M5、K14的细胞质对HT-29细胞增殖能力有显著抑制作用（P＜0.05）;HT-29细胞经乳酸菌细胞壁或细胞质（蛋白质含量为80 μg/mL）处理48 h后,脱氧核糖核酸（DNA）出现了明显的弥散拖尾形态;乳酸菌X12、M5和K14细胞壁诱导HT-29细胞凋亡,并调控癌细胞周期分布。通过筛选最终获得乳酸菌X12、M5和K14的细胞壁成分具有抗结肠癌作用。     

Antioxidant activity of peptides isolated from alfalfa leaf protein hydrolysate

Alfalfa leaf protein, a potential source of high quality protein for human consumption, was hydrolyzed with protease. Alfalfa leaf protein hydrolysate was fractionated by ultrafiltration and the obtained peptides were purified by dynamical adsorption. The antioxidant activity of alfalfa leaf peptides (ALPs) was investigated and compared with that of a native antioxidant, reduced glutathione (GSH), which was used as a reference. The reducing power of ALPs was 0.69 at 2.00 mg/mL. ALPs at 1.60 mg/mL and 0.90 mg/mL exhibited 79.71% and 67.00% of scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide radical, respectively. In addition, ALPs showed 65.15% chelating effect on ferrous ion at 0.50 mg/mL. The molecular weight of the peptides was determined and 67.86% of the total amount was below 1000 Da. Combined with the result of the amino acid profiles, ALPs was believed to have high nutritive value in addition to antioxidant activity.     

Antioxidant activities of volatile components isolated from Eucalyptus species

Extracts of three species of eucalyptus leaves (Eucalyptus polyanthemos Schauer, E globulus Labill and E perriniana) and their major volatile components were assessed for antioxidant activity in two different assays. The inhibitory effect of each extract and its components towards aldehyde/carboxylic acid conversion was measured over a period of 30 days. Their inhibitory effects towards malonaldehyde formation from lipid by oxidation with Fenton's reagent were also measured; the extract from E polyanthemos inhibited the oxidation of hexanal completely for 30 days at a level of 200 and 500 µg ml^?1. It also inhibited malonaldehyde (MA) formation in cod liver oil by 86% at the 160 µg ml^?1 level. At the 500 µg ml^?1 level, thymol, 1,8‐cineole, benzyl alcohol and terpinen‐4‐ol identified in the extract from E polyanthemos reduced the extent of hexanal oxidation over a period of 30 days by 100, 96, 82 and 75% respectively. In the lipid/MA assay, thymol, benzyl alcohol, terpinen‐4‐ol and 1,8‐cineole inhibited MA formation by 80, 63, 58 and 26% respectively at the level of 160 µg ml^?1. Thymol exhibited potent antioxidant activity comparable to that of the known natural antioxidant α‐tocopherol. © 2001 Society of Chemical Industry     

Antioxidant and antiproliferative activities of phytochemicals from Quince (Cydonia vulgaris) peels

Fifty-nine secondary metabolites have been isolated from Cydonia vulgaris peels and characterised on the basis of their spectroscopic features. Among them, five metabolites, 3β-(18-hydroxylinoleoyl)-28-hydroxyurs-12-ene (12), 3β-linoleoylurs-12-en-28-oic acid (15), 3β-oleoyl-24-hydroxy-24-ethylcholesta-5,28(29)-diene (24), tiglic acid 1-O-β-d-glucopyranoside (35), and 6,9-dihydroxymegastigmasta-5,7-dien-3-one 9-O-β-d-gentiobioside (46), have been isolated and elucidated for the first time. All of the compounds were tested for their radical-scavenging and antioxidant activities by measuring their capacity to scavenge the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical, and anion superoxide radical and to induce the reduction of Mo(VI) to Mo(V). The antiproliferative activity of all the most abundant compounds by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) bioassay on murine B16-F1 melanoma cells has been also assessed.