鱼腥草多糖的抑菌作用

目的:研究鱼腥草多糖的抑菌作用。方法:以鱼腥草新鲜全草为原料,采用水提醇析法和超声波协助提取鱼腥草多糖;运用琼脂扩散法分析检测鱼腥草多糖的抑菌作用。结果与结论:所提取的鱼腥草多糖对大肠杆菌、金黄色葡萄球菌有一定的抑制作用,且通过超声波提取的多糖抑菌效果更好。     

鱼腥草体细胞胚胎发生和植株再生

目的:利用鱼腥草的叶片和叶柄为材料,进行体细胞胚胎诱导及植株再生研究。方法:运用正交设计试验,考察在改良的MS固体培养基上添加不同种类、不同浓度的植物生长物质组合及其配比对鱼腥草愈伤组织诱导、体细胞胚胎发生及植株再生的影响。结果:鱼腥草无菌苗叶片在含有2,4-D 1.0 mg/L 6-BA 0.5 mg/L的改良MS培养基上能诱导出胚性愈伤组织;胚性愈伤组织在含有6-BA 1.0 mg/L的改良的MS培养基上诱导体细胞胚的发生;叶柄在含有6-BA 1.0 mg/L改良MS培养基上直接产生体细胞胚。体细胞胚在改良的MS NAA0.1 mg/L 6-BA 1.0 mg/L的培养基上能够快速繁殖,形成大量不定芽,在不加任何激素的MS培养基上就可以萌发出不定根,发育为成完整植株,在MS IBA 1.0 mg/L的固体培养基上能够形成大量的根。结论:建立了鱼腥草体细胞胚胎发生及植株再生的体系。     

鱼腥草挥发油的化学成分

The volatile oils from Houttuynia cordata Thunb. were obtained with supereritical CO2, steam distillation and petroleum ether extraction and analyzed qualitatively and quantitatively by GC-MS. The results showed that the chemical constituents of the volatile oils by three different methods are very different. The extraction rates of volatile oil by above-mentioned three extraction methods are 1.764%, 0.040% and 0.082%, respectively. The volatile oil extracted by supercritical CO2 extraction, which the content of houttuyninum reached 14.393 %, is better than those with traditional methods.     

鱼腥草组培体系优化及耐低温突变体的筛选

为解决豫北地区没有鱼腥草栽培,缺乏耐低温能越冬材料的需求,本实验以鱼腥草茎段为外植体进行不同植物生长调节剂及其浓度的组织培养诱导侧芽发生,优化了鱼腥草侧芽组织培养体系;使用不同浓度的甲基磺酸乙酯（EMs）诱变侧芽,诱导耐低温突变体,通过测定诱变材料可溶性糖含量、过氧化氢酶（CAT）和超氧化物歧化酶（SOD）活性变化鉴定材料耐寒性。结果表明茎段侧芽诱导的最佳植物生长调节剂组合培养基MS＋6-BA2．0mg·L-1＋NAA0．2mg·L-1;诱变处理的最佳组合为0．4％EMS处理6h,获得8株耐低温突变体;侧芽生根的最佳浓度组合为1／2MS＋NAA0．8mg·L-1。     

三白草不同部位及鱼腥草挥发油成分的GC-MS比较分析

采用水蒸气蒸馏法提取,气相色谱-质谱联用技术(GC-MS)对三白草不同部位及鱼腥草挥发油化学成分进行定性和定量分析。共分离鉴定出88个化合物,从三白草地上部分鉴定出36个,根茎中鉴定出31个,分别占挥发油总量的73.38%和95.53%,其中仅13个共有成分;从鱼腥草中鉴定出50个化合物,占挥发油总量的74.59%。三白草地上部分与根茎挥发油中化学成分含量和组成有明显差异,且均不含有甲基正壬酮。     

鱼腥草抑菌有效成分的醇提、鉴定及抑菌效果研究

以大肠埃希菌抑菌效果为指标,采用正交实验的方法对鱼腥草抑菌有效成分的醇提条件进行优化,同时对鱼腥草醇提液进行分极分离,采用HPLC和GC-MS的方法对抑菌有效部的成分进行鉴定,并对该有效部的抑菌效果进行初步研究。实验结果表明鱼腥草抑菌有效成分醇提的最佳条件为醇浓度70%,温度80℃、料液比1?15,提取时间4 h,该条件下所获得的醇提液分极分离所获得的氯仿部抑菌效果最好,GC-MS和HPLC分析表明氯仿部中含有13种酚类物质及少量的鱼腥草素和甲基正壬酮,该有效部对大肠埃希菌(MIC:16.0 mg/mL)、金黄色葡萄球菌(MIC:8.0 mg/mL)、白色念珠菌(MIC:4.0 mg/mL)、黄曲霉(MIC:8.0 mg/mL)以及黑曲霉(MIC:8.0mg/mL)均有较好的抑菌效果。     

薇菜、蕺菜中氨基酸及其他营养素含量的测定

对秦巴山区薇菜 (Osmundajaponicathunb .)、蕺菜 (Houttuyniacordatathunb.)两种山野菜可食部分中氨基酸、灰分、粗蛋白、粗脂肪、粗纤维、总糖等含量进行了测定。结果表明 :所测定的 1 7种氨基酸中 ,薇菜含 1 7种氨基酸 ,蕺菜含 1 6种氨基酸 ,七种必需氨基酸含量占各自氨基酸总量的百分数分别为 4 3 .2 6%、3 6.58%。薇菜、蕺菜灰分含量分别为 8.1 1 %、9.4 0 % ;粗蛋白含量分别为 2 2 .80 %、1 7.2 2 % ;粗脂肪含量分别为 3 .3 4 %、5.4 3 % ;粗纤维含量分别为 1 3 .0 7%、1 7.89% ;总糖含量分别为 2 1 .1 4 %、1 3 .4 2 %。     

铅、锌及其交互作用对鱼腥草(Houttuynia cordata)叶绿素含量及抗氧化酶系统的影响

采用营养液培养方法研究铅、锌及其交互作用对鱼腥草叶绿素含量及抗氧化酶系统的影响。实验结果显示，随着Pb浓度的增加，鱼腥草叶绿素含量逐渐降低但无显著变化。Zn在一定浓度下能提高鱼腥草叶绿素含量，而在高浓度Zn胁迫下，叶绿素含量急剧下降。鱼腥草叶片中SOD、POD和CAT3种酶活性都是随着Pb浓度的增加先上升后下降。随着Zn浓度的增加，SOD和CAT也是先上升后下降，POD则是逐渐上升。Pb—Zn交互作用增加了鱼腥草叶绿素含量，对SOD和POD活性具有抑制作用，对CAT活性影响不明显。同时研究结果还表明，单一Pb、Zn对鱼腥草叶绿素含量和抗氧化酶系统的影响大于Pb、Zn二者的共同作用，其中高浓度Zn对鱼腥草的伤害作用最大，而当溶液Pb处理浓度达到400mg／L时，鱼腥草仍能正常生长，说明鱼腥草具有较强的耐Pb能力。     

鄂西北产鱼腥草提取物体外抗氧化性的四种化学方法评价

采用α-脱氧核糖法、邻苯三酚自氧化法、DPPH法、铁氰化钾还原法等4种国内外常用的体外抗氧化活性检测方法,对鄂西北产鱼腥草石油醚提取物、无水乙醇提取物、乙酸乙酯提取物、三氯甲烷提取物的抗氧化性进行化学评价,结果表明鱼腥草提取物具有一定抗氧化性,其浓度与其抗氧化活性强弱顺序一致。     

Alkaloids from aerial parts of Houttuynia cordata and their anti-inflammatory activity

New alkaloids, houttuynamide B and C (1, 2) and houttuycorine (14), were isolated from the aerial parts of Houttuynia cordata Thunb. in addition to eighteen known alkaloids. Their structures were elucidated through extensive spectroscopic analysis. All the isolates were tested for their inhibitory activity against NO production in RAW 264.7 cells stimulated by LPS. Of the tested compounds, compound 15 showed the most potent anti-inflammatory activity with an IC₅₀ value of 8.7 μM.     

High-frequency induction of multiple shoots and clonal propagation from rhizomatous nodal segments of Houttuynia cordata Thunb.—An ethnomedicinal herb of India

Summary This study reports an efficient and direct shoot bud differentiation and multiple shoot induction from nodal segments of underground stoloniferous rhizomes of Houttuynia cordata Thumb. The frequency of shoot bud regeneration was influenced by the type of cytokinin and concentrations. Among the various concentrations used, benzylaminopurine (BAP, 17.74 μM) or kinetin (Kn, 18.58 μM) was found to be most effective for rapid and maximum shoot but differentiation. The number of shoots per explant was higher (20.00±2.61) on Murashige and Skoog (MS) medium supplemented with Kn (18.58 μM) compared to BAP and 6-γ-γ-(dimethyl-allylamino)-purine (2iP) during initial 40-d-old culture. Subsequent shoot differentiation and multiplication were achieved in MS medium containing 9.29 μM Kn and 15% (v/v) coconut milk. Elongation and growth of multiple shoots were also obtained on MS medium containing either 2.32 μM Kn or 2.46 μM 2iP alone. The rate of shoot multiplication during subcultures declined with an increase in the size of proliferating shoot cluster. Reducing shoot cluster size to three to four shoots and subculturing together in shoot multiplication medium resulted in a better shoot multiplication and growth, which could be maintained for 2 yr. The elongated shoots (>20 mm) were successfully rooted on MS medium supplemented with 19.60 μM indole-3-butyric acid. Regenerated plants were successfully established in soil and were found to be healthy and uniform. The protocol reported in this study can be used for conservation and utilization of elite clone of H. cordata.     

The antimicrobial activity of heyneanol A extracted from the root of Taiwanese wild grape

Aims:  To search for antimicrobial compounds against pathogenic bacteria from grape vines ( Vitis spp.). To investigate the antimicrobial efficacy of active compounds towards methicillin-resistant Staphylococcus aureus (MRSA).
Methods and Results:  The root extracts of taiwanese wild grape ( Vitis thunbergii var. taiwaniana ) showed marked activities against Gram-positive bacteria using the disc diffusion method. After purification, the active compound 1 was confirmed as heyneanol A by mass spectroscopy and nuclear magnetic resonance. Heyneanol A showed an minimum inhibitory concentration (MIC) value of 2  μ g ml⁻¹ towards MRSA and a value of 2 to 4  μ g ml⁻¹ for Enterococcus faecium , S. aureus , Streptococcus agalactiae and Streptococcus pyogenes . In addition, the contents of heyneanol A were determined as 36 mg g⁻¹ in roots of taiwanese wild grape.
Conclusions:  The root extracts of grapevines have good antimicrobial activities towards some strains of Gram-positive pathogens. Heyneanol A, the major antimicrobial compound, is especially active towards MRSA. In addition, the abundances of heyneanol A and other stilbenes in the roots of grapevines make it possible to produce natural antimicrobial compounds from this plant species.
Significance and Impact of the Study:  This study reports for the first time the antimicrobial compounds in the root extracts of grapevines. The results will have clinical significance owing to their activities against MRSA.     

An extract from teak (Tectona grandis) bark inhibited Listeria monocytogenes and methicillin resistant Staphylococcus aureus

AIMS: The aim of this study was to characterize the inhibitory mechanism in teak (Tectona grandis) bark and to determine its effectiveness against Listeria monocytogenes and methicillin resistant Staphylococcus aureus (MRSA). METHODS AND RESULTS: Methanol extracts of teak bark were inhibitory to L. monocytogenes and MRSA by means of disc diffusion. Gas chromatography-mass spectrometry, and (1)H and (13)C nuclear mass resonance analyses revealed that the inhibitory compound had a molecular weight of 174, and a structure of 5-hydroxy-1,4-naphthalenedione (Juglone). CONCLUSIONS: 5-hydroxy-1,4-naphthalenedione (Juglone) inhibited L. monocytogenes and MRSA. SIGNIFICANCE AND IMPACT OF THE STUDY: A compound in an extract of teak bark was inhibitory to L. monocytogenes and MRSA.     

Inhibitory effects of food additives derived from polyphenols on staphylococcal enterotoxin A production and biofilm formation by Staphylococcus aureus

In this study, we examined the inhibitory effects of 14 food additives derived from polyphenol samples on staphylococcal enterotoxin A (SEA) production and biofilm formation by Staphylococcus aureus. Tannic acid AL (TA), Purephenon 50 W (PP) and Polyphenon 70A (POP) at 0.25 mg/mL and Gravinol®-N (GN), Blackcurrant polyphenol AC10 (BP), and Resveratrol-P5 (RT) at 1.0 mg/mL significantly decreased SEA production by S. aureus C-29 (p < 0.05). TA, GN, BP, and RT significantly inhibited the expression of the sea gene in S. aureus C-29 (p < 0.05), while suppression attempts by PP and POP proved unsuccessful. After result analysis, it can be derived that TA, GN, BP, and RT inhibit the production of SEA. Of the six samples, each one significantly inhibited biofilm formation (p < 0.05). Food additives derived from polyphenols have viability to be used as a means to inhibit the enterotoxin production and control the biofilm formation of foodborne pathogens.     

Phytochemical analysis and antibacterial activity towards methicillin-resistant Staphylococcus aureus of leaf extracts from Argania spinosa (L.) Skeels

Argania spinosa (L.) Skeels is an endemic Moroccan species belonging to Sapotaceae family. In this work, lipophilic and aqueous extracts were obtained from leaves and subjected to a chemical profiling by MS and LC-MS/MS. Pentacyclic terpenoids were identified and quantified in the lipophilic fraction, while phenolic compounds (mainly belonging to flavonols and flavan-3-ols) were identified in the aqueous fraction. The antibacterial activities of fractions were evaluated in vitro against both reference Gram-positive and -negative bacterial strains and clinical isolates of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA); in addition, the compounds quantified as main components in each extract were assayed against reference strains. A relevant antibacterial activity was observed against reference MSSA and MRSA strains of S. aureus: for the lipophilic fraction, MIC₅₀ values obtained were 177.8 and 170.6 μg/mL for the former and the latter, respectively, while for the aqueous fraction were 215.5 and 233.3 μg/mL. These inhibitory activities could be mainly ascribed to ursolic and oleanolic acids, among pentacyclic terpenoids, and to quercetin concerning phenolic compounds. A remarkable antibacterial activity was also observed against clinical isolates, thus argan leaves can be considered of interest in the chemotherapy of human infections.     

Chemical fingerprint,acute oral toxicity and anti-inflammatory activity of the hydroalcoholic extract of leaves from Tocoyena formosa (Cham. & Schlecht.) K. Schum

Inflammation is a protective response of the organism against damaging agents, this process is considered beneficial, however in some situations, this response can be damage when exacerbated effect are present. This claim objective to evaluate the qualitative and quantitative chemical profile, acute toxic and anti-inflammatory effects of the hydroalcoholic extract of leaves from Tocoyena formosa (Cham. & Schlecht.) K. Schum. (HELTF). Quantitative and qualitative phytochemical analysis was performed by HPLC-DAD and colorimetric assay. The topical anti-inflammatory activity was determined in Croton oil-induced ear edema assay and systemic activity was performed in vascular permeability, paw edema induced by carrageenan and dextran. Phytochemical analysis of leaves from HELTF showed presence of tannin, flavonoid, saponins an other that confirmed by HPLC analysis. The extract did not cause significant with LD₅₀ greater than 5000 mg/kg and did not promote significate reduction in topical inflammatory process. However, HELTF demonstrate significant reduction of paw edema induced by carrageenan and dextran. The HELTF (200 mg/kg) reduced the protein/cell migration in the intradermal carrageenan-induced inflammation. Our results demonstrated that the first time the chemical profile and describe the effective action in systemic anti-inflammatory, antiedematogenic activity and low acute toxicity. This activity presents, supporting its traditional use. However, new studies are necessary for the detection and clarification of the possible mechanism of action.     

Biological and biochemical characterization of two new PLA2 isoforms Cdc-9 and Cdc-10 from Crotalus durissus cumanensis snake venom

This work reports the purification, biological characterization and amino acid sequence of two new basic PLA₂ isoforms, Cdc-9 and Cdc-10, purified from the Crotalus durissus cumanensis venom by one step analytical chromatography reverse phase HPLC. The molecular masses of the PLA₂ were 14,175 ± 2.7 Da for Cdc-9 and 14,228 ± 3.5 Da for Cdc-10 both deduced by primary structure and confirmed by MALDI-TOF. The isoforms presented an amino acid sequence of 122 amino acid residues, being Cdc-9: SLVQFNKMIK FETRKSGLPF YAAYGCYCGW GGQRPKDATD RCCFVHDCCY GKVAKCNTKW DIYSYSLKSG YITCGKGTWC KEQICECDRV AAECLRRSLS TYKNEYMFYP DSRCREPPEY TC with pI value of 8.25 and Cdc-10: SLLQFNKMIK FETRKSGVPF YAAYGCYCGW GGRRPKDPTD RCCFVHDCCY GKLTKCNTKW DIYSYSLKSG YITCGKGTWC KEQICECDRV AAECLRRSLN TYKNEYMFYP DSRCRGPPEY TC with a pI value of 8.46, showing highly conserved Ca²⁺-binding and catalytic sites. The PLA₂ activity decreased when the isoforms Cdc-9 and Cdc-10 were incubated with 4-bromophenacyl bromide (p-BPB), anhydrous acetic acid and p-nitrobenzene sulfonyl fluoride (NBSF) when compared with the activity of both native isoforms. In mice, the PLA₂ isoforms Cdc-9 and Cdc-10 induced myonecrosis and edema. Myotoxic and edema activities were reduced after treatment of the isoforms with p-BPB; acetylation of the lysine residues and the treatment of PLA₂ with NBSF have also induced edema reduction. However, p-BPB strongly diminishes the local and systemic myotoxic effects.