不同黄酮类单体对CHO细胞早期损伤作用的比较研究

选用竹叶中4 种黄酮单体荭草苷、异荭草苷、绿原酸和阿魏酸,在各毒性剂量下作用于中国仓鼠卵巢（Chinese hamster ovary,CHO）细胞,通过检测其对细胞早期损伤指标--线粒体功能变化的影响,以评估其细胞损伤作用。CCK-8检测法测得4 种单体物质对CHO细胞的IC50值分别是：绿原酸2 726.11 μmol/L、阿魏酸1 680.28 μmol/L、荭草苷1 889.15 μmol/L、异荭草苷2 358.56 μmol/L。在各单体IC50、1/2 IC50值、1/4 IC50值、1/8IC50值剂量下,线粒体膜电位变化具有剂量依赖性,其中以阿魏酸降低幅度最明显,绿原酸次之,荭草苷和异荭草苷变化较小;三磷酸腺苷（adenosine triphosphate,ATP）生成量与作用剂量成负相关,阿魏酸致ATP生成量降低最多,荭草苷次之,绿原酸和异荭草苷影响较小;细胞色素C的释放量,以阿魏酸最大,荭草苷和异荭草苷次之,绿原酸的最小。研究表明4 种单体物质都对线粒体产生了一定的损伤,其中阿魏酸对线粒体影响最大,荭草苷和异荭草苷次之,绿原酸最小。     

紫甘薯花色苷制备及其抗猪传染性胃肠炎病毒(TGEV)活性的研究

为研究紫甘薯花色苷对猪传染性胃肠炎病毒(TGEV)的抑制作用,实验纯化了紫甘薯花色苷提取物,并采用液质联机的方法鉴定其结构组成;将制备的花色苷提取物作用于侵染TGEV的猪睾丸(ST)细胞,研究对TGEV诱导ST细胞的形态学变化和凋亡情况的影响,揭示花色苷对TGEV的预防和治疗效果。结果表明:紫甘薯花色苷提取物中主要含8种花色苷。花色苷质量浓度低于60μg/mL时,ST细胞生长良好且无细胞毒性;接种TGEV后,20μg/mL的花色苷就能抑制TGEV的增殖,且在安全浓度范围内抑制程度成剂量关系。在此体外实验中,花色苷对TGEV的预防效果比治疗效果更明显。结论:紫甘薯花色苷在20～60μg/mL质量浓度范围内对TGEV有很好的抗病毒功效。      

山楂黄酮提取物的抗氧化活性和对癌细胞生长抑制作用

目的:研究山楂(Crataegus pinnatifida Bunge)黄酮提取物的抗氧化能力以及对人肝癌Hep-G2细胞和人肠癌Caco-2细胞生长抑制作用。方法:比较测定总黄酮含量的直接法和两种铝盐显色法,进一步采用硝酸铝盐显色法测定提取物总黄酮含量,ABTS法和DPPH法分析提取物的抗氧化活性,MTT法评价山楂黄酮提取物对细胞生长的抑制效果。结果:山楂黄酮提取物中黄酮含量占干质量的98%,清除ABTS和DPPH自由基的能力随提取物剂量的增加而升高,EC50分别为88μg/mL和112μg/mL,而标准品Trolox的EC50清除ABTS和DPPH自由基的能力分别为111μg/mL和118μg/mL。山楂黄酮提取物能够有效地抑制癌细胞的生长,且对Hep-G2细胞的抑制效果更强,Hep-G2细胞和Caco-2细胞的IC50分别约为115μg/mL和376μg/mL。结论:山楂黄酮提取物黄酮含量高,抗氧化能力强,有抑制癌细胞的作用,是一种有效的天然抗氧化剂。     

蜂胶醇提物对人肝癌细胞Hep G2增殖及凋亡的影响

为探讨蜂胶醇提物对人肝癌细胞Hep G2 增殖和凋亡的影响,采用MTT 法检测蜂胶醇提物对Hep G2 细胞增殖的抑制作用,用荧光倒置显微镜和流式细胞仪分析蜂胶醇提物对Hep G2 细胞凋亡的影响。结果表明：12.5～200μg/mL 质量浓度的蜂胶醇提物作用24、48h 后,均能不同程度地抑制Hep G2 细胞的增殖,呈明显的时间、剂量依赖关系,半数抑制质量浓度(IC50)分别是115、78μg/mL。作用8h 后,Hep G2 细胞出现不同程度的凋亡,凋亡率由6.36% 上升到21.9%,呈现出剂量依赖关系。故蜂胶醇提物可显著抑制人肝癌细胞Hep G2 的生长,诱导其凋亡。     

灵芝多糖联合5-FU对人结肠癌HCT-116细胞增殖及凋亡的影响

目的：探讨灵芝多糖(GLP)联合5-氟尿嘧啶(5-FU)对人结肠癌HCT-116细胞增殖抑制及凋亡的影响。方法：采用MTT法测定单独和联用GLP与5-FU对人结肠癌HCT-116细胞的协同抑制作用,应用联合指数法分析两药物之间相互作用,Hoechst33258荧光染色观察细胞的形态学改变,碘化吡啶(PI)标记流式细胞术(FCM)检测GLP联合5-FU对HCT-116细胞周期和凋亡抑制率的变化。结果：MTT法测定结果显示GLP和5-FU单独用药均能显著抑制HCT-116细胞增殖。GLP(＞659μg/mL)联用5-FU(＞1.6μg/mL)联用呈协同效应(CI＜1),与5-FU单独用药组相比有极显著差异(P＜0.01),并呈时间依赖性。给药48h后,Hoechst33258荧光染色可见典型的凋亡形态学特征。FCM检测凋亡显示两药联合作用24h后,5mg/mL GLP联合50μg/mL 5-FU的凋亡率为36.14%,高于5-FU(50μg/mL)单独用药组(26.07%);1.25mg/mL GLP联合12.5μg/mL 5-FU、2.5mg/mL GLP联合25μg/mL 5-FU、5mg/mL GLP联合50μg/mL 5-FU作用48h后,凋亡率分别为20.95%、32.87%、30.01%,均高于5-FU(50μg/mL)单独用药组(14.51%)。联合用药组可使HCT-116细胞阻滞于S期。结论：较高质量浓度的GLP与5-FU联用具有协同抑制人结肠癌细胞株HCT-116细胞增殖,诱导细胞凋亡,阻滞细胞周期作用。     

竹叶黄酮对小鼠脾细胞免疫的分子机制研究

目的:研究竹叶黄酮对小鼠脾细胞的免疫作用。方法:采用分子免疫学、细胞生物学和分子生物学等多种技术评价了竹叶黄酮对小鼠的免疫增强作用。结果:在一定剂量范围内竹叶黄酮可促进小鼠脾脏细胞DNA和蛋白质的合成,促进了细胞的增殖,同时促进了小鼠脾细胞IFNγmRNA的表达,IFNγ的产生与分泌,IFNγ又反过来激活NK细胞,促进T、B细胞分化和CTL成熟,刺激B细胞分泌抗体。结论:一定剂量的竹叶黄酮能增强小鼠的免疫调节能力,并呈明显的剂量效应关系。     

笃斯越桔花青素提取物对3T3-L1前脂肪细胞生长抑制作用

目的：研究笃斯越橘花青素提取物对3T3-L1 前脂肪细胞生长抑制作用及其作用机理。方法：采用MTT法观察细胞生长抑制并确定半数抑制浓度(IC50),LDH(lactate dehydrogenase)法评价提取物引起的细胞膜损伤,流式细胞计法测定细胞周期,荧光显微镜观察凋亡细胞的形态学特征。结果：笃斯越橘花青素提取物能够有效地抑制3T3-L1 前脂肪细胞的生长且IC50 约为214μg/mL;LDH 实验表明细胞LDH 释放率在24、48、72h 分别为89.0%、85.2%、67.8%,72h 时相对24h 或48h 明显降低(P ＜ 0.05),提取物对3T3-L1 前脂肪细胞膜的通透性未见明显增加;笃斯越橘花青素提取物能够有效诱导细胞凋亡,同时在S 或G0/G1 期产生阻滞,但是对细胞的G2/M 期未见明显影响,荧光显微镜观察细胞出现典型凋亡特征。结论：笃斯越橘花青素提取物能有效抑制3T3-L1 前脂肪细胞生长的作用,具有开发为天然抗肥胖功能因子的潜在可能。     

苦荞麸皮黄酮抗氧化及抗肿瘤活性

以西南地区的两种苦荞麸皮为实验材料（重庆酉阳苦荞麸皮（T1）;四川西昌苦荞麸皮（T2））,通过氧化自由基吸收能力实验（oxygen radical absorbance capacity,ORAC）测定苦荞麸皮黄酮的化学抗氧化能力,采用人肝癌细胞HepG2为细胞模型,研究苦荞麸皮黄酮的细胞抗氧化活性（cellular antioxidant activity,CAA）及对He pG2 细胞抗增殖活性。结果表明： T 1 和T 2 苦荞麸皮黄酮的ORAC值分别为（ 5 7 . 0±3 . 5 ） 、（73.6±6.3）μmol TE/g。T1和T2苦荞麸皮黄酮的细胞抗氧化值分别为（44.4±5.2）、（52.5±2.7）μmolQE/100 g（PBS清洗）;（32.9±3.2）、（30.9±2.2）μmol QE/100 g（不经PBS清洗）。在对HepG2细胞体外抗增殖活性研究实验中,通过与对照组细胞相比,发现当苦荞麸皮黄酮的质量浓度为21.9 mg/mL时,T1和T2苦荞麸皮黄酮对HepG2细胞增殖的抑制率分别约为51%和82%（P＜0.01）,二者相应的EC50值分别为（23.0±0.5）mg/mL和（13.7±0.1）mg/mL。因此,苦荞麸皮黄酮具有一定的体外细胞抗氧化和抗增殖的能力,可将苦荞麸皮作为此类功能性食品开发的原料资源。     

茶提取物和纳米表没食子儿茶素没食子酸酯对6-羟基多巴胺诱导的SH-SY5Y细胞保护作用

以6-羟基多巴胺（6-hydroxydopamine,6-OHDA）诱导的SH-SY5Y细胞系作为帕金森病（Parkinson’sdisease,PD）体外细胞模型,探究茶提取物（L-茶氨酸、咖啡碱、茶多酚、表没食子儿茶素没食子酸酯（epigallocatechin-3-gallate,EGCG）、茶黄素、茶色素）和两种纳米EGCG对SH-SY5Y细胞的毒性和对6-OHDA诱导的SH-SY5Y细胞保护作用的差异,综合评价茶提取物治疗PD的潜力。结果表明：茶提取物毒性作用由弱到强为茶多酚＜L-茶氨酸＜茶色素＜咖啡碱＜茶黄素＜EGCG;保护作用由强到弱为茶黄素＞EGCG＞茶多酚＞茶色素＞咖啡碱＞L-茶氨酸;茶黄素（0.2 μg/mL）和EGCG（0.9 μg/mL）预处理6-OHDA诱导的SH-SY5Y细胞,细胞存活率分别为（99.59±2.24）%和（95.84±2.50）%,保护作用明显强于其他茶提取物;相较于EGCG,纳米EGCG具有毒性作用更弱和保护作用更强的特点。由此可知,茶作为一种日常饮品,具有较好地治疗PD的潜力。     

Characterization of antioxidant compounds in aqueous coriander extract (Coriandrum sativum L.)

An aqueous coriander extract obtained through a sequential extraction process, was analysed using chromatography and mass spectrometry in order to identify the phenolic compounds responsible for its antioxidant activity. Four fractions were identified from the crude extract using chromatography in a silica gel column. Their antioxidant activity, according to the β-carotene/linoleic acid model, was similar to one another but inferior to that of the crude extract and of butylated hydroxytoluene. Of the phenols identified through gas chromatography and mass spectrometry, it was noted that caffeic acid was present in high concentration (4.34 μg/ml in fraction I and 2.64 μg/ml in fraction III), whereas protocatechinic acid and glycitin were present in high concentration in fraction II (6.43 μg/ml) and fraction IV (3.27 μg/ml), respectively. These results, when considered with the recognized antioxidant ability of phenolic acids, suggest that they are principal components responsible for the antioxidant activity of the aqueous coriander extract.     

Inhibition of proliferation of human carcinoma cell lines by phenolic compounds from a bearberry-leaf crude extract and its fractions

Phenolic compounds were extracted from the leaves of bearberry, a potential functional food ingredient, using 80% (v/v) aqueous ethanol after which the resultant crude extract was applied to a Sephadex LH-20 column. A fraction comprising low-molecular-weight phenolics (LMW fraction) and sugars was eluted from the column with 95% (v/v) ethanol. A tannin fraction was then obtained after switching the mobile phase to acetone/water (1:1, v/v). Phenolic compounds present in the crude extract and its two fractions showed antiproliferative activities in a concentration-dependent manner against five carcinoma cell lines, namely MCF-7 (estrogen receptor-positive breast carcinoma), DU-145 (androgen receptor-negative prostate carcinoma), HT-29 (colon carcinoma), SK-MEL-5 and MDA-MB-435 (melanoma; skin carcinoma). IC₅₀ data revealed that the tannin fraction was best at retarding cell proliferation in the tested cancer cell lines. The greatest inhibition at 1.5 μg fraction/mL assay was observed for the HT-29 colon carcinoma cell line. The proliferation of SK-MEL-5 skin carcinoma cells was also strongly inhibited by both the crude extract and LMW fraction. MDA-MB-435 cells were found to be the least sensitive for the materials tested, particularly for the LMW fraction.     

广林9号桉叶多酚抗氧化活性研究

采用不同极性有机溶剂对广林9号桉叶提取物进行系统萃取分离,用福林-酚法测定各组分的总酚含量,以1,1-二苯基-2-三硝基苯肼(DPPH)、2,2＇-联氮-双-(3-乙基苯并噻唑啉-6-磺酸)(ABTS)、还原能力3种体外抗氧化活性方法测定了桉叶各组分的抗氧化活性。结果表明,不同萃取组分中,乙酸乙酯组分总酚含量最高,达到502.67mg/g;其对DPPH自由基和ABTS＋·的清除能力和还原能力也最强,优于阳性对照物茶多酚,其清除两种自由基的IC50分别为0.097mg/mL 和0.034mg/mL;通过总酚含量与抗氧化活性比较发现,其抗氧化活性与总酚含量成正相关,由此判断桉叶提取物的抗氧化活性成分主要为多酚类物质;桉叶粗提物中多酚含量达到30%以上,与茶叶粗提物中多酚含量相当,具有开发意义。     

菱角壳分级萃取物对肿瘤细胞增殖及凋亡的影响

目的:制备菱角壳乙醇提取物的分级萃取物,并研究其对肿瘤细胞增殖及凋亡的作用。方法:采用有机溶剂萃取法将菱角壳乙醇提取物分为乙酸乙酯萃取物和正丁醇萃取物2个不同极性部分,并测定其黄酮与多酚含量,CCK-8法测定菱角壳分级萃取物对肿瘤细胞增殖的抑制作用,流式细胞术检测菱角壳萃取物诱导肿瘤细胞凋亡的作用。结果:乙酸乙酯萃取物中多酚和黄酮含量高于正丁醇萃取物。在两种萃取物浓度为25、50、100、200、400 μg/mL时均能抑制胃癌细胞(SGC-7901)、肝癌细胞(Hep G2)的增殖,最高抑制率均达60%以上,并存在明显的剂量与效应关系。两种萃取物均能促进肿瘤细胞凋亡,400 μg/mL的乙酸乙酯、正丁醇萃取物作用肝癌细胞24 h,凋亡率分别为45.57%和33.34%;作用胃癌细胞24 h,凋亡率分别为31.01%和21.65%。结论:菱角壳乙酸乙酯萃取物具有抑制肿瘤细胞增殖及促肿瘤细胞凋亡的生物活性。     

Differential effects of polyphenols-enriched extracts from hawthorn fruit peels and fleshes on cell cycle and apoptosis in human MCF-7 breast carcinoma cells

This study was to investigate the anticancer effects of the peel polyphenolic extract (HPP) and flesh polyphenolic extract (HFP) from hawthorn fruit in human MCF-7 breast cancer cells. It was found that the polyphenol and flavonoid contents of HPP were significant higher than that of HFP. Both HPP and HFP inhibited cell growth in a dose-dependent manner with the IC₅₀ of 88.6 μg/mL and 175.5 μg/mL, respectively, suggesting that HPP was more effective against MCF-7 cells than HFP. Flow cytometric analysis revealed that both HPP and HFP mediated the cell-cycle arrest at the S-phase, and also dose-dependently led to apoptosis of MCF-7 cells via the mitochondrial pathway, as evidenced by the activation of caspase-3 and caspase-9 and the elevation of intracellular ROS production. All these findings indicate that hawthorn fruit, especially its peel, is an excellent source of natural chemopreventive agents in the treatment of breast cancer.     

Antioxidant activity and phenolic compounds of fractions from Portulaca oleracea L.

Portulaca oleracea fractions obtained from the crude extract of the plant by reversed-phase separation were investigated for their antioxidant activities and phenolic compounds content. Five fractions were classified based on optical absorption between the wavelength range of 200–400 nm. Fraction 3 displayed higher absorption than the other fractions. The total amount of quantified phenolics in this fraction was found to be quite high compared to that of crude extract. Chlorogenic, caffeic, p-coumaric, ferulic and rosmarinic acids were the free phenolic acids, and quercetin and kaempferol were the free flavonoids detected in Fraction 3. IC₅₀ value of crude extract was found to be 511.8 μg/ml whereas Fraction 3 exhibited an IC₅₀ value of 154.1 μg/ml. TEAC of Fraction 3 was found to be almost four times higher than that of the crude extract. Fraction 3 was also found to show the highest lipid peroxidation inhibiting capacity, determined by TBARS assay.     

Evaluation of antioxidant property of extract and fractions obtained from a red alga, Polysiphonia urceolata

Antioxidant activity (AA), total phenolic content, and reducing power of the crude extract, fractions, and subfractions derived from a red alga, Polysiphonia urceolata, were evaluated and determined. The antioxidative activity was measured using the α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging assay and the β-carotene–linoleate assay systems, and compared with that of butylated hydroxytoluene (BHT), gallic acid (GA), and ascorbic acid (AscA). The results showed that the crude extract and the ethyl acetate-soluble fraction exhibited higher AA than BHT in the DPPH assay model, at all of four concentration levels tested (from 0.4 to 50 μg/ml), while, in the β-carotene–linoleate assay system, the crude extract and the ethyl acetate-soluble fraction exhibited similar or, in most cases, higher AA than GA and AscA at the same concentrations (from 10 to 200 μg/ml). The ethyl acetate-soluble fraction was further fractionated into seven subfractions F1–F7 by silica gel vacuum liquid chromatography. F1 was found to be the most effective subfraction in both assay systems. The total phenolic content and reducing power were determined using the Folin–Ciocalteu and the potassium ferricyanide reduction methods, respectively. Statistical analysis indicated a significant association between the antioxidant potency and total phenolic content as well as between the antioxidant potency and reducing power.     

蜂胶提取物对诺如病毒的体外抑制作用研究

为研究蜂胶提取物对人源诺如病毒的体外抑制作用,采用小鼠诺如病毒和噬菌体MS2病毒为替代病毒,研究蜂胶水提物和醇提物随浓度及时间变化对小鼠诺如病毒和噬菌体MS2病毒的抑制作用及其机制.浓度相关性实验表明:随着蜂胶醇提物浓度增加,小鼠诺如病毒和MS2病毒滴度呈显著下降趋势,当醇提物质量浓度达到500μg/mL时,小鼠诺如病...     

Antioxidant and antimicrobial activities of Laetiporus sulphureus (Bull.) Murrill

Antioxidant capacity and antimicrobial activities of Laetiporus sulphureus (Bull.) Murrill. extracts obtained with ethanol were investigated in this study. The study was aimed at determining the antioxidant activity (DPPH free radical-scavenging, β-carotene/linoleic acid systems), total phenolic content and total flavonoid concentration of L. sulphureus. Inhibition values both of L. sulphureus ethanol and the standards increased parallel with the elevation of concentration in the linoleic acid system. Inhibition values of L. sulphureus (LS) extract, BHA and α-tocopherol standards were found to be 82.2%, 96.4% and 98.6%, respectively, at a concentration of 160 μg/ml. DPPH free radical-scavenging activity was found to exhibit 14%, 26%, 55% and 86% inhibition, respectively, at concentrations of 100, 200, 400 and 800 μg/ml. Total flavanoids were 14.2 ± 0.12 μg mg⁻¹ (quercetin equivalent) while the phenolics were 63.8 ± 0.25 μg mg⁻¹ (pyrocatechol equivalent) in the extract. Positive correlations were found between total phenolic content in the mushroom extracts and their antioxidant activities. Edible mushrooms may have potential as natural antioxidants. L. sulphureus showed narrow antibacterial activity against Gram-negative bacteria and strongly inhibited the growth of the Gram-positive bacteria tested. The crude extract exhibited high anticandidal activity on Candida albicans. Therefore, the extracts could be suitable as antimicrobial and antioxidative agents in the food industry.     

不同浓度苦丁茶对TCA8113人舌鳞癌细胞的体外抗癌效果

对一种市售苦丁茶进行TCA8113人舌鳞癌细胞体外抗癌效果评价。通过MTT（3-（4,5-二甲基噻唑-2）-2,5-二苯基四氮唑溴盐）比色法实验、DAPI（4’,6-二脒基-2-苯基吲哚）荧光染色分析、RT-PCR（逆转录聚合酶链式反应）和Westernblot分析,研究其抗癌效果。通过MTT法测定苦丁茶对癌细胞体外生长抑制效果时发现,200μg/mL浓度的苦丁茶（75%癌细胞生长抑制率）对TCA8113人舌鳞癌细胞生长有相对最强的抑制效果。DAPI染色分析显示,与100、50μg/mL苦丁茶相比,使用200μg/mL浓度的苦丁茶,对TCA8113细胞有较强的诱其凋亡的能力。在RT-PCR和Westernblot分析结果中,凋亡因子Bax（B细胞淋巴瘤/白血病基因伴随蛋白x）、caspase-3（半胱天冬氨酸酶-3）、caspase-9（半胱天冬氨酸酶-9）的mRNA和蛋白质表达得到增强,Bcl-2（B细胞淋巴瘤/白血病基因-2）表达减弱。综合分析得出,一定浓度的苦丁茶具有良好的防癌抗癌效果。