翼蓼块根提取物的抗氧化活性和血管紧张素转化酶抑制活性研究

本文主要对翼蓼块根的甲醇提取物及其乙酸乙酯、正丁醇、水萃取层的DPPH自由基清除能力、还原力、金属离子螯合能力和ACE抑制活性进行研究。四种提取物的总酚含量分别为147.97、228.31、162.99、168.16mg没食子酸/g,黄酮含量分别为19.45、21.57、13.89、14.80 mg槲皮素/g。DPPH自由基清除能力的EC50值分别为52.37、11.43、46.45、50.32μg/m L。四种提取物的还原能力均表现出随着浓度增加,其还原能力也增加的趋势;当终浓度为100μg/m L时,各提取物还原能力均强于抗氧化剂BHA。在100μg/m L时,乙酸乙酯层具有最强的金属螯合能力。在ACE抑制实验中,甲醇提取物和乙酸乙酯层在100μg/m L时,抑制率分别为39.45%和39.76%。实验结果表明,翼蓼块根的总酚和总黄酮含量与其抗氧化活性呈正相关。抗氧化活性与其对应的ACE抑制活性存在一定程度的联系,具体发挥ACE抑制活性的单体化合物尚需要进一步分离分析研究。     

河南鼠尾草抑制体内外α-糖苷酶活性研究

本文采用96微孔板法,首次对河南鼠尾草抑制酵母和大鼠小肠α-葡萄糖苷酶活性进行研究。河南鼠尾草乙酸乙酯提取物(IC50=28.73μg/mL)和正丁醇提取物(IC50=73.90μg/mL)抑制酵母α-葡萄糖苷酶活性远高于阳性对照Acarbose(IC50=1081.27μg/mL),但只有乙酸乙酯提取物(IC50=366.79μg/mL)具有抑制大鼠小肠α-葡萄糖苷酶活性,阳性对照Acarbose未检测出其IC50。结果表明,河南鼠尾草乙酸乙酯提取物和正丁醇提取物均具有较好的酵母α-葡萄糖苷酶抑制活性,但只有乙酸乙酯提取物具有良好的大鼠小肠α-葡萄糖苷酶抑制活性。     

不同品种菊花和贵州产野菊花中木犀草素的含量比较

目的测定并比较不同品种菊花和贵州产野菊花中木犀草素的含量。方法用高效液相色谱法测定木犀草素的含量。色谱柱为ODS柱（4．6mm×250mm,5μm）,流动相为甲醇-水-冰醋酸（体积比45：55：0．4）,检测波长为254nm,流速1．0mL／min。结果7个菊花样品的木犀草素含量,以贵州野菊花的木犀草素含量最高（3．876mg／g）,杭菊的木犀草素含量最低（0．302mg／g）。结论贵州产野菊花中木犀草素的含量均高于其他品种菊花,具有较高的药用价值。     

草麻黄对α-葡萄糖苷酶的抑制作用研究

采用96微孔板法测定草麻黄抑制α-葡萄糖苷酶活性.草麻黄正丁醇(IC50=6.86 μg/mL)、乙酸乙酯(IC50 =77.28 μg/mL)和石油醚部位(IC50=190.20 μg/mL)抑制活性远高于阳性对照阿卡波糖(IC50=1081.27μg/mL).研究表明,草麻黄各部位均具有很好的α-筒萄糖苷酶抑制活性,可进行活性追踪分离活性成分.     

蜈蚣草化学成分及抑制乙酰胆碱酯酶生物活性研究

采用多种分离分析手段对蜈蚣草(Pteris vittata)乙醇提取物进行系统的化学成分和乙酰胆碱酯酶抑制活性研究,应用现代波谱技术鉴定了其中的6个化学成分,分别是芹菜素(1)、芹菜素-7-O-β-D-葡萄糖苷(2)、木犀草素(3)、木犀草素-7-O-β-D-葡萄糖(4)、山柰素-3-O-β-D-葡萄糖苷(5)、β-谷甾醇(6),所有化合物均系首次从该种中获得。化合物5具有一定抑制乙酰胆碱酯酶活性。     

木犀草素通过抑制肝癌细胞Sp1活性上调抑癌基因OPCML表达

抑癌基因OPCML的甲基化失活是肿瘤发生的重要机制,因此采用药物逆转抑癌基因的失活状态是肿瘤防治的重要策略。研究表明,Luteolin可在一定程度上抑制DNA的甲基化转移酶(methyltransferase)的活性,但木犀草素是否能逆转OPCML的失活状态目前尚不明确。本研究通过体外培养肝癌细胞系HepG2,用不同浓度木犀草素处理后,采用实时定量PCR和Western blotting分别检测OPCML、DNMT1的m RNA和蛋白表达;甲基特异性PCR(MSP)和DNA甲基转移酶(DNA methyltransferases)催化实验分析OPCML基因启动子区域甲基化及细胞核中甲基化活性;ELISA分析木犀草素处理前后对核转录因子Sp1活性的变化;RNA干扰及慢病毒转染等方法观察Sp1在介导甲基化及CPCML表达中的作用。最后建立裸鼠异种移植瘤动物模型,观察木犀草素对异种移植瘤生长的抑制作用。结果显示,Hep G2细胞基础状态下OPCML表达水平较低,其启动子区域甲基化水平较高,而经0~30μmol/L木犀草素处理后,能显著增强OPCML蛋白和m RNA的表达,并能降低其启动子甲基化水平以及细胞核中甲基化活性。同时,木犀草素也能抑制Hep G2细胞中Sp1的活性以及DNMT1的表达。si RNA干扰OPCML后,可逆转木犀草素对Hep G2细胞的生长抑制效应,上调细胞内Sp1表达后,同时伴有DNMT1表达增加及OPCML表达降低。此外,木犀草素也能上调裸鼠异种移植瘤中OPCML表达并抑制移植瘤生长的生长。以上结果表明木犀草素可能通过降低细胞内甲基化水平而上调OPCML基因表达,最终抑制Hep G2细胞生长增殖。     

土茯苓叶和种子的抗氧化活性研究

本文研究了土茯苓叶和种子的乙醇提取物不同组分的抗氧化活性。通过采用DPPH法、ABTS法、FRAP法、抗红细胞氧化溶血以及抑制肝肾组织中MDA的生成这5种体外抗氧化方法,并以BHA为阳性对照,发现土茯苓叶乙酸乙酯组分的清除DPPH自由基能力(IC50=21.15±2.90μg/m L)、抗红细胞溶血(IC50=21.93±0.96μg/m L),抑制肝肾组织中MDA生成(肝IC50=1.34±0.14μg/m L,肾IC50=7.69±1.88μg/m L)在土茯苓叶和种子不同组分中效果最好;土茯苓叶正丁醇组分的ABTS自由基的清除能力(IC50=2.29±0.19μg/μL)和还原Fe3+的能力(Trolox当量=3768.44±16.93μmol/g)效果最好,差异均具有统计学意义(P0.05)。因此,土茯苓叶和种子均具有抗氧化活性,且叶的效果要优于种子,有望开发为一种抗氧化剂。     

滇重楼茎叶总皂苷抗肝癌HepG2细胞活性

探究滇重楼茎叶总皂苷对肝癌HepG2细胞增殖的抑制、细胞周期阻滞及诱导细胞凋亡作用。从滇重楼地上茎叶提取总皂苷,配制成浓度为10μg/m L、20μg/m L、40μg/m L、80μg/m L和160μg/m L的总皂苷提取物处理HepG2细胞。总皂苷提取物对细胞增殖的抑制作用采用MTT法检测;对细胞周期阻滞作用采用流式细胞术检测;诱导细胞凋亡的作用采用细胞核荧光染色、流式细胞术和caspase-3活性试剂盒检测。结果表明,滇重楼茎叶总皂苷提取物能显著抑制细胞增殖,且具有时间、剂量依赖效应,能阻滞细胞周期于S期,并能诱导细胞凋亡。但其诱导凋亡作用仅高剂量组(≥80μg/m L)效果显著,低剂量组(80μg/m L)不显著。     

补肾活血方中单体成分的体外炎性抑制作用研究

本文采用LC-MS技术进行定性分析,确定补肾活血方水提液中存在芍药苷、阿魏酸、白藜芦醇、蛇床子素及补骨脂素等单体化合物。利用酶联免疫法(ELISA)测定试药对模型细胞释放TNF-α、IL-6及NO的抑制作用。与空白组比较,模型组TNF-α、IL-6、NO含量明显升高(P0.0);与模型组比较,阿魏酸、白藜芦醇、补骨脂素及复方水提部位在100μg/m L,以及蛇床子素在20、100μg/m L均对TNF-α的释放具有显著的抑制(P0.01);阿魏酸及补骨脂素在100μg/m L,白藜芦醇及蛇床子素在20、100μg/m L均对IL-6水平具有显著的抑制(P0.01);芍药苷及复方水提部位在100μg/m L,阿魏酸、白藜芦醇、蛇床子素及补骨脂素在20、100μg/m L均对NO的释放具有显著抑制(P0.01)。结果表明单体对炎性因子的释放抑制作用总体上强于复方水提部位,提示补肾活血方的治疗骨关节炎活性可能是通过抑制炎症介质释放,降低TNF-α、IL-6、NO等含量发挥作用,这对验证复方药效活性,探究效应物质基础具有重要意义。     

螺旋藻源血管紧张素转化酶抑制肽的纯化和鉴定

血管紧张素转化酶(ACE)抑制剂通过影响肾素-血管紧张素系统,对减缓和抑制高血压具有重要的作用.该研究通过超滤、凝胶过滤色谱、反相高效液相色谱等方法,从钝顶螺旋藻的木瓜蛋白酶水解液中分离、纯化得到一种血管紧张素转化酶(ACE)抑制肽,并利用基质辅助激光解吸电离-飞行时间质谱(MALDI-TOF-MS)和氨基酸测序对纯化肽进行鉴定.此外,对其抑制类型和体外模拟消化环境稳定性也进行了研究.结果表明,分子质量范围为0～3000ku的酶解液ACE抑制活性最高,IC50值为(1.03±0.04)g/L.该部分酶解液通过纯化获得ACE抑制肽,IC50值为(0.0094±0.0002)g/L,相当于(27.36±0.14)μmol/L,序列经鉴定为Val-Glu-Pro.Lineweaver-Burk图和Dixon图表明该ACE抑制肽为非竞争性抑制剂,Ki值为(23.59±0.54)μmol/L.体外稳定性实验显示,该抑制肽在胃蛋白酶、胰凝乳蛋白酶、胰蛋白酶等胃肠蛋白酶的消化下能够保持良好的抑制活性,表明螺旋藻源ACE抑制肽可以用于降血压功能食品和药剂方面,具有很好的发展前景.     

毛筒壳科真菌次级代谢产物生物活性的评价

毛筒壳科Tubeufiaceae真菌具有产新结构、新活性次级代谢产物的潜力,目前对该科真菌次级代谢产物的研究较少。为了寻找具有生物活性的新化合物,有必要对毛筒壳科真菌次级代谢产物及其活性进行系统深入的研究。本文采用平板对峙法、生长速率法和MTT法,分别测定已分离得到的19株该科真菌活体菌株抑菌活性、发酵物抑菌活性以及发酵物粗提物对不同人体肿瘤细胞株增殖的抑制作用。通过平板对峙法,试验共筛选获得13株活性菌株,其中,红棕毛筒腔菌菌株Tubeufia rubra PF02-2对7种植物病原真菌有明显的抑菌效果,抑制率均高于60%且抑菌谱广。采用生长速率法,发现红棕毛筒腔菌菌株PF02-2经液体发酵后,发酵液对其中4种植物病原真菌仍有一定的抑制作用,且菌丝体部分的乙酸乙酯提取物对马铃薯早疫病病菌Alternaria solani（ZYB）的抑制效果最好。通过MTT法,发现发酵物粗提物对3种肿瘤细胞均具有不同程度的细胞毒活性,其中在300μg/mL时,剑叶莎毛筒腔菌菌株Tubeufia machaerinae ML03-2发酵液部分的乙酸乙酯提取物对人宫颈癌细胞株HeLa和人前列腺癌细胞株PC-3的抑制率（%）分别达到了98.92±0.15和97.86±0.18,在400μg/mL时,对人肝癌细胞株HEPG2的抑制率（%）达到了98.88±0.04;在500μg/mL时,明孢新旋卷孢菌菌株Neohelicosporium hyalosporum ML05-1菌丝体部分的乙酸乙酯提取物对人宫颈癌细胞株HeLa细胞的抑制率（%）为98.32±0.02,在600μg/mL时,对人肝癌细胞株HEPG2的抑制率（%）达到了97.62±0.20,在300μg/mL时,对人前列腺癌细胞株PC-3的抑制率（%）达到了98.91±0.02。该研究结果为开发利用毛筒壳科真菌提供了科学依据。     

Metabolite profile and in vitro activities of Phagnalon saxatile (L.) Cass. relevant to treatment of Alzheimer’s disease

The present study describes for the first time the in vitro properties (inhibition of NO production and anticholinesterase) of Phagnalon saxatile (L.) Cass. (Asteraceae). The methanolic extract showed antioxidant activity that was measured by DPPH assay and β-carotene bleaching test. The same extract inhibited NO production in the murine monocytic macrophage cell line RAW 264.7. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition was assessed by modifications of Ellman’s method. Purification of the MeOH extract of P. saxatile allowed the isolation of phenolic compounds. Among them, the compounds that most effectively inhibited lipopolysaccharide-induced NO production were caffeic acid and methylchlorogenic acid, with IC₅₀ values of 7?μg/mL and 12?μg/mL, respectively. Luteolin and 3,5-dicaffeoylquinic acid exhibited the most promising activity against AChE with an IC₅₀ of 25.2 and 54.5?μg/mL, respectively, while caffeic acid and luteolin exhibited higher activity against BChE with an IC₅₀ of 32.2 and 37.2?μg/mL, respectively.     

Antioxidant,anti‐inflammatory,and enzyme inhibitory activity of natural plant flavonoids and their synthesized derivatives

The synthesized flavonoid derivatives were examined for their antioxidant, anti‐inflammatory, xanthine oxidase (XO), urease inhibitory activity, and cytotoxicity. Except few, all the flavonoids under this study showed significant antioxidant activity (45.6%–85.5%, 32.6%–70.6%, and 24.9%–65.5% inhibition by DPPH, ferric reducing/antioxidant power, and oxygen radical absorption capacity assays) with promising TNF‐α inhibitory activity (42%–73% at 10 μM) and IL‐6 inhibitory activity (54%–81% at 10 μM) compared with that of control dexamethasone. The flavonoids luteolin, apigenin, diosmetin, chrysin, O^3?, O⁷‐dihexyl diosmetin, O^4?, O⁷‐dihexyl apigenin, and O⁷‐hexyl chrysin, showed an inhibition with IC₅₀ values (4.5‐8.1 μg/mL), more than allopurinol (8.5 μg/mL) at 5 μM against XO and showing more than 50% inhibition at a final concentration (5 mM) with an IC₅₀ value of ranging from 4.8 to 7.2 (μg/mL) in comparison with the positive control thiourea (5.8 μg/mL) for urease inhibition. Thus, the flavonoid derivatives may be considered as potential antioxidant and antigout agents.     

Coptisine-induced inhibition of Helicobacter pylori: elucidation of specific mechanisms by probing urease active site and its maturation process

In this study, we examined the anti-Helicobactor pylori effects of the main protoberberine-type alkaloids in Rhizoma Coptidis. Coptisine exerted varying antibacterial and bactericidal effects against three standard H. pylori strains and eleven clinical isolates, including four drug-resistant strains, with minimum inhibitory concentrations ranging from 25 to 50?μg/mL and minimal bactericidal concentrations ranging from 37.5 to 125?μg/mL. Coptisine’s anti-H. pylori effects derived from specific inhibition of urease in vivo. In vitro, coptisine inactivated urease in a concentration-dependent manner through slow-binding inhibition and involved binding to the urease active site sulfhydryl group. Coptisine inhibition of H. pylori urease (HPU) was mixed type, while inhibition of jack bean urease was non-competitive. Importantly, coptisine also inhibited HPU by binding to its nickel metallocentre. Besides, coptisine interfered with urease maturation by inhibiting activity of prototypical urease accessory protein UreG and formation of UreG dimers and by promoting dissociation of nickel from UreG dimers. These findings demonstrate that coptisine inhibits urease activity by targeting its active site and inhibiting its maturation, thereby effectively inhibiting H. pylori. Coptisine may thus be an effective anti-H. pylori agent.     

Anti-inflammatory action of herbal medicine comprised of Scutellaria baicalensis and Chrysanthemum morifolium

ABSTRACT

Various mixtures were prepared depending on the mixing ratio of Scutellaria baicalensis hot water extract (SB-HW), and Chrysanthemum morifolium ethanol extract (CM-E) and their anti-inflammatory activity were compared. Among them, SB-HW (80 μg/mL)/CM-E (120 μg/mL) or SB-HW (40 μg/mL)/CM-E (160 μg/mL) significantly inhibited LPS-stimulated NO and IL-6 levels in RAW 264.7 cells. The SB-HW (80 μg/mL)/CM-E (120 μg/mL) mixture, which was determined as active mixture, significantly reduced MUC5AC secretion in PMA and LPS-induced NCI-H292 cells. The active mixture also reduced the production of PGE₂ and IL-8 in PMA-induced A549 cells. LC-MS/MS analysis showed that the active mixture was composed of high contents of flavone glycosides, such as baicalin and cynaroside. Western blot analysis indicated that the active mixture suppressed phosphorylation of ERK, JNK, and p38, associating with the inhibition of MAPK signaling. Taken together, our results suggest that the active mixture could be applied as a new anti-inflammatory herbal medicine.     

白柄肉齿菌Sarcodon leucopus多酚生物碱提取物的体外抗氧化及降血糖活性

为探讨西藏白柄肉齿菌Sarcodon leucopus子实体多酚生物碱提取物（PAE）的抗氧化和降糖活性,本研究考察了PAE对DPPH自由基清除能力、细胞内抗氧化能力（CAA）和糖尿病关键酶（大鼠小肠来源麦芽糖酶、蔗糖酶和α-淀粉酶）活性的抑制能力。结果表明,PAE具有一定的抗氧化活性,对DPPH自由基的半数抑制浓度（IC₅₀）为(18.12±1.09)μg/mL,对细胞内抗氧化能力表现为CAA₅₀=(13.60±0.13)μg/mL;PAE对糖尿病关键酶的抑制活性有一定选择性,对麦芽糖酶和蔗糖酶具有抑制作用,并呈剂量效应关系,其IC₅₀分别(60.86±4.50)μg/mL和(64.60±4.53)μg/mL,而对α-淀粉酶抑制作用极低。研究结果表明PAE有潜在的抗氧化及降血糖活性,具有开发为安全高效的天然降血糖功能食品和药物的潜力。     

Antibacterial properties of a glycolipid-rich extract and active principle from Nunavik collections of the macroalgae Fucus evanescens C. Agardh (Fucaceae)

This study investigated the antibacterial activity of glycolipid-rich extracts of the brown macroalga Fucus evanescens in cell culture. Accessions were collected on the Arctic coast of Ungava Bay, Nunavik, Quebec. The crude ethyl acetate extract of these accessions showed strong antibacterial activity (≥4 log(10) cfu) against Hemophilus influenzae , Legionella pneumophila , Propionibacterium acnes (ATCC and clinical isolate), and Streptococcus pyogenes at 100?μg/mL. This algal extract inhibited by 3 log(10) Clostridium difficile and methicillin-resistant Staphylococcus aureus , whereas Bacillus cereus , Escherichia coli , Klebsiella pneumoniae , and Pseudomonas aeruginosa were not significantly affected. Further investigations of the activity of a glycolipid-rich fraction, extracted with dichloromethane, against Propionibacterium acnes showed an MIC(100) of 50?μg/mL, with an inhibition of more than 99% at only 7.8?μg/mL. The main active compound, a β-d-galactosyl O-linked glycolipid, was synthesized for the bioassay and showed an MIC(100) of 50?μg/mL but lost its activity more quickly with only 50% of inhibition at 12.5?μg/mL. Therefore, the semipurified F. evanescens extract could be a good choice for future research into the development of alternative treatments for acne therapy.     

黑木耳中抑制胰脂肪酶活性物质的提取工艺及体外抑制效果

本文以黑木耳醇提物和水提物为研究对象,以对胰脂肪酶活性的抑制率为指标,分别对其提取工艺进行了单因素和正交试验,选取优化后抑制率高的提取物进行抑制类型和3T3-L1前脂肪细胞方面的研究。结果表明醇提物的最佳提取工艺为提取温度70℃、提取时间1h、乙醇浓度90%、料液比1:20,抑制胰脂肪酶的IC₅₀=681.56μg/mL。水提物的最佳提取工艺为提取温度70℃、提取时间2h、料液比1:40,抑制胰脂肪酶的IC₅₀=850.59μg/mL,醇提物的抑制效果优于水提物。醇提物对胰脂肪酶的抑制类型为非竞争性抑制,抑制常数为4.69mg/mL;醇提物浓度低于1mg/mL时,对3T3-L1前脂肪细胞的活性无影响;浓度高于400μg/mL时即可显著抑制前脂肪细胞的分化。     

灵芝子实体中不同极性的三萜体外抗肿瘤及抗炎活性比较

为了解灵芝中不同极性三萜活性的差异,运用大孔树脂将灵芝总三萜根据极性大小进行分段,采用高效液相法分析各极性部分的HPLC指纹图谱和三萜含量,并比较其对不同肿瘤细胞增殖的抑制作用和抗炎活性。结果显示D-101大孔树脂可以有效地将灵芝总三萜分为中等极性和低极性两部分,两部分的三萜含量分别为(279.00±2.90)mg/g、(94.52±2.03)mg/g。其中,低极性三萜的体外抗肿瘤活性明显强于中等极性三萜,其对K562、SW620、L1210细胞增殖抑制的IC₅₀值分别为(74.12±1.94)μg/mL、(121.45±2.13)μg/mL、(13.52±1.13)μg/mL。另外,低极性三萜对RAW264.7细胞呼吸爆发的抑制作用也明显强于中等极性三萜。进一步对低极性三萜和中等极性三萜单体的抗炎活性进行比较,发现低极性三萜灵芝烯酸F、灵芝酸DM、灵芝醇B对RAW264.7细胞呼吸爆发的抑制作用明显强于极性较高的灵芝酸C₂、灵芝酸A。该研究阐明了灵芝子实体中不同极性三萜部位的抗肿瘤及抗炎活性并不相同,为将来新药开发和灵芝质量标准的改进建立了基础。     

Phytochemical screening and anti-oxidant activity of Sargassum wightii enhances the anti-bacterial activity against Pseudomonas aeruginosa

In this study, the phytochemical, phenolic, flavonoid and bioactive compounds were successfully screened from crude extract of Sargassum wightii by LC-MS analysis after NIST interpretation. Bacterial growth inhibition study result was shown with 24 mm zone inhibition at 200 µg/mL concentration against P. aeruginosa. The increased phenolic content was much closed to gallic acid and the range was observed at 250 μg/mL concentration. In addition, flavonoid contents of the algae extract was indicated more significant with rutin at 200 μg/mL. In result, both the phenolic and flavonoid contents of the extract were more correlated with gallic acid and rutin. Further, the total anti-oxidant and DPPH radical scavenging activities were shown increased activity at 200 μg/mL concentrations. Furthermore, the excellent anti-bacterial alteration result was observed at 200 μg/mL concentration by minimum inhibition concentration. Therefore, the result was revealed that the marine algae Sargassum wightii has excellent phytochemical and anti-oxidant activities, and it has improved anti-bacterial activity against P. aeruginosa.