Anti-Helicobacter pylori activity of Plumbago zeylanica L

It has been shown that the presence of infection by Helicobacter pylori is strongly associated with gastric cancer and peptic ulceration. In western medicine, a 3-fold therapeutic regimen, emphasizing the use of antibiotics, is typically used to suppress H. pylori activity. However, antibiotic drug resistance frequently develops as a consequence of such treatment. In our previous study, 50 Taiwanese folk medicinal plants were screened for their anti-H. pylori activities. The results revealed that Plumbago zeylanica L. had the highest inhibitory effects against H. pylori. In this study, therefore, we have focused on establishing the anti-H. pylori activities of P. zeylanica L. Water and the organic solvents ethanol, ethyl acetate and acetone were used for P. zeylanica L. extraction, obtaining yields of 1.66-6.84% (w/w). Excluding the water extract, higher anti-H. pylori activity was demonstrated for all the extracts, both using the agar diffusion and dilution methods. The ethyl acetate extract exhibited the lowest minimum inhibitory concentrations against five H. pylori strains, of which ranged from 0.32 to 1.28 mg ml-1, followed, in ascending order, by the acetone, ethanol and water analogs. Bactericidal activity was determined for P. zeylanica L. extracts, with the lowest minimum bactericidal concentrations (5.12-20.48 mg ml-1) demonstrated for the ethyl acetate, followed, in ascending order, by the acetone and ethanol analogs. Bactericidal activity appeared to be in a dose-dependent manner. Through a broad pH range (2-7), bactericidal activity was not affected when extract concentrations were greater than or equal to the minimum bactericidal concentration. High stability was demonstrated for the ethyl acetate P. zeylanica L. extract within pH range of 1-7, exhibiting all pH treatments bactericidal activity.     

Anti-Helicobacter pylori activities of six Iranian plants

BACKGROUND: Helicobacter pylori is the major worldwide cause of bacterial gastrointestinal infections in adults and children. Antibiotic therapy and a combination of two or three drugs have been widely used to eradicate these infections. However, development of drug resistance in bacteria calls for new sources of drugs, and plants seem to be a logical source of new antibacterial compounds. METHODS: The anti-H. pylori activities of six native Iranian plants (Glycyrrhiza aspera, Juglans regia, Ligustrum vulgare, Thymus kotschyanus, Trachyspermum copticum and Xanthium brasilicum) and seven antibiotics were determined against 70 clinical isolates from children using the disk susceptibility assay. Minimum inhibitory concentrations were also measured for the biologically active extracts. One extract with the best anti-H. pylori activity was fractionated by silica gel and thin layer chromatography and the active compounds were identified by hydrogen nuclear magnetic resonance ((1)HNMR) spectroscopy. RESULTS: All plant extracts showed anti-H. pylori activity by the disk sensitivity method, but the most active extracts were those from X. brasilicum and T. copticum. In fact, the anti-H. pylori activities of the two extracts were superior to the disk antibiotic susceptibility profile. Minimum inhibitory concentrations were within the range of 31.25-250 micro g/ml. Fractionation and chemical identification of the extract from X. brasilicum showed the presence of two substances, a flavonoid and a xanthanolide. CONCLUSIONS: Due to the rise in antibiotic resistance, new sources of anti-H. pylori drugs are needed. The use of medicinal plants and/or their chemical components may have potential benefit in eradicating such problems.     

Screening of certain medicinal plants from India for their anti-quorum sensing activity

Discovery of quorum sensing (QS) system to coordinate virulence and biofilm formation in bacterial pathogens has triggered search for safe, stable and non-toxic anti-QS compounds from natural products. Ethanolic extracts of 24 Indian medicinal plants were tested by agar well and disc diffusion assay for anti-QS activity using Chromobacterium violaceum (CV12472 and CVO26) reporter strains. AHL from C. violaceum CV31532 was isolated and partially purified for its use in CVO26 based bioassay. Effect on swarming-motility of Pseudomonas aeruginosa (PAO1) was also recorded at sub-MIC concentrations of extracts. Of the 24 medicinal plants screened Hemidesmus indicus (L.) Schult (root), Holarrhena antidysenterica (Roth) A.DC. (bark), Mangifera indica L. (seed) Punica granatum L. (pericarp) and Psoralea corylifolia L. (seed) demonstrated varying level of inhibition of violacein production in the reporter strains. Moreover, a significant reduction in swarms was recorded over control. The inhibition of violacein production and swarming motility may be due to direct or indirect interference on QS by active constituents or the interactive effect of different phytocompounds present in the extracts. These plant extracts may be selected for activity guided fractionation to identify and characterize the active principle.     

Pachysandra型生物碱的化学结构及活性筛选

本文简要报道黄杨科凳果族植物中Ｐａｃｈｓａｎｄｒａ型生物碱的化学结构研究概况及药理活性筛选的初步结果。药理活性筛选结果表明,筛选的化合物大多具有抗癌（Ｐ３８８和Ｌ１２１０）活性,部分化合物显示较高活性的抗溃疡作用。     

Antiviral activity of south Brazilian medicinal plant extracts.

Brazilian plants are potential sources of useful edible and medicinal plants. Hydromethanolic extracts prepared from 54 medicinal plants used in folk medicine to treat infections were screened for antiviral properties against five different viruses (HSV-1, HSV-2, poliovirus type 2, adenovirus type 2 and VSV). Fifty-two percent of the plant extracts exhibited antiviral against one or more tested viruses. More specifically, 42.6% showed activity against HSV-1 (herpes simplex virus type 1), 42.6% against HSV-2 (herpes simplex virus type 2), 26% against poliovirus and 24% against VSV (vesicular stomatitis virus). None of the extracts was active against adenovirus. Trixis praestans (Vell.) Cabr. and Cunila spicata Benth. extracts were further characterized for antiviral activity.     

三种维药提取物对蛋白酪氨酸磷酸酶1B抑制作用的研究

蛋白酪氨酸磷酸酶1B(PTP1B)是胰岛索增敏的新靶点之一.本文研究了芳香新塔花、沙生蜡菊、驱虫斑鸠菊等3种维药石油醚提取物对PTP1B活性的影响及其对酶的抑制类型.结果表明,所构建的原核表达系统能高表达重组PTP1B(his-PTP1B1-321),分子量为40.8 kDa.3种维药提取物对PTP1B均表现出不同程度...     

Preliminary studies of Mammea americana L. (Guttiferae) bark/latex extract point to an effective antiulcer effect on gastric ulcer models in mice

Plant extracts are some of the most attractive sources of new drugs and have shown promising results for the treatment of gastric ulcers. Several folk medicinal plants and herbs have been used to treat gastrointestinal disorders, including gastric ulcers. Mammea americana L. (Guttiferae) fruit is very common in the diet of the population of northern South America. Our research interest in this plant arose because of its potential medicinal value as a tonic and against stomachache, as used in folk medicine. In this paper we evaluated three different extracts (ethanolic/EtOH, methanolic/MeOH and dichloromethane/DCM) obtained from M. americana L., for their ability to protect the gastric mucosa against injuries caused by necrotizing agents (0.3 M HCl/60% EtOH), hypothermic restraint stress, nonsteroidal anti-inflammatory drugs (NSAID, indomethacin) and pylorus ligation. In the HCl/EtOH-induced gastric-ulcer model, EtOH and DCM extracts demonstrated significant inhibition of the ulcerative lesion index by 54% (12.0 +/- 2.6 mm) and 86% (3.7 +/- 1.8 mm), respectively, in relation to the control value (26.0 +/- 1.4 mm) (p<0.0001). In the NSAID/cholinomimetic-induced lesion model, both EtOH and DCM extracts showed antiulcerogenic effects with significant reduction in the damage to these gastric lesions of 36% (8.3 +/- 2.0 mm) and 42% (7.5 +/- 1.4 mm), respectively, as compared to the control group (13.0 +/- 0.9 mm) (p<0.0001). In the gastric ulcer induced by hypothermic-restraint stress, both extracts also showed significant activity, and inhibited the gastric lesion index by 58% and 75%, respectively. The EtOH and DCM extracts also changed gastric juice parameters as well as those of cimetidine, decreased gastric acid secretion significantly (p<0.0001), increased pH values and promoted reduced acid output (p<0.0001). In all gastric-ulcer-induced models, MeOH extract did not show any significant antiulcerogenic activity, nor did it change gastric-juice parameters (p>0.05). The results suggest that EtOH and DCM extracts obtained from M. americana possess excellent antisecretory and/or gastrotective effect in all gastric ulcer models. These results suggest that the antiulcerogenic compound(s) present in M. americana may be clustered in the apolar fraction, which will be investigated by our group for the probable mechanisms of action.     

Antioxidant activity and phenolic compounds of 112 traditional Chinese medicinal plants associated with anticancer

Cancer prevention and treatment using traditional Chinese medicines have attracted increasing interest. This study characterizes antioxidant activity and phenolic compounds of traditional Chinese medicinal plants associated with anticancer, comprising 112 species from 50 plant families. The improved ABTS(*+) method was used to systematically assess the total antioxidant capacity (Trolox equivalent antioxidant capacity, TEAC) of the medicinal extracts. The TEAC values and total phenolic content for methanolic extracts of herbs ranged from 46.7 to 17,323 micromol Trolox equivalent/100 g dry weight (DW), and from 0.22 to 50.3 g of gallic acid equivalent/100 g DW, respectively. A positive, significant linear relationship between antioxidant activity and total phenolic content (all R(2) values>/=0.95) showed that phenolic compounds were the dominant antioxidant components in the tested medicinal herbs. Major types of phenolic compounds from most of the tested herbs were preliminarily identified and analyzed, and mainly included phenolic acids, flavonoids, tannins, coumarins, lignans, quinones, stilbenes, and curcuminoids. These medicinal herbs exhibited far stronger antioxidant activity and contained significantly higher levels of phenolics than common vegetables and fruits. Traditional Chinese medicinal plants associated with anticancer might be potential sources of potent natural antioxidants and beneficial chemopreventive agents.     

Peptide deformylase is a potential target for anti-Helicobacter pylori drugs: reverse docking, enzymatic assay, and X-ray crystallography validation

Colonization of human stomach by the bacterium Helicobacter pylori is a major causative factor for gastrointestinal illnesses and gastric cancer. However, the discovery of anti-H. pylori agents is a difficult task due to lack of mature protein targets. Therefore, identifying new molecular targets for developing new drugs against H. pylori is obviously necessary. In this study, the in-house potential drug target database (PDTD, http://www.dddc.ac.cn/tarfisdock/) was searched by the reverse docking approach using an active natural product (compound 1) discovered by anti-H. pylori screening as a probe. Homology search revealed that, among the 15 candidates discovered by reverse docking, only diaminopimelate decarboxylase (DC) and peptide deformylase (PDF) have homologous proteins in the genome of H. pylori. Enzymatic assay demonstrated compound 1 and its derivative compound 2 are the potent inhibitors against H. pylori PDF (HpPDF) with IC50 values of 10.8 and 1.25 microM, respectively. X-ray crystal structures of HpPDF and the complexes of HpPDF with 1 and 2 were determined for the first time, indicating that these two inhibitors bind well with HpPDF binding pocket. All these results indicate that HpPDF is a potential target for screening new anti-H. pylori agents. In addition, compounds 1 and 2 were predicted to bind to HpPDF with relatively high selectivity, suggesting they can be used as leads for developing new anti-H. pylori agents. The results demonstrated that our strategy, reverse docking in conjunction with bioassay and structural biology, is effective and can be used as a complementary approach of functional genomics and chemical biology in target identification.     

中草药浸提液对小列当种子发芽的影响

选用240种常用中草药,研究其蒸馏水和甲醇浸提液原液及其10倍、100倍和1 000倍稀释液对小列当种子发芽的影响.结果表明:小列当种子在蒸馏水浸提液刺激下发芽率超过70%的中草药有灯心草、降香和莲须,在甲醇浸提液刺激下发芽率超过70%的中草药有百部、桑椹、谷芽和萆薢;蒸馏水浸提液对小列当种子发芽抑制率超过50%的中草药有菊花、棕榈、苦杏仁和黄柏,甲醇浸提液对小列当种子发芽抑制率超过70%的有续断、地黄、肉豆蔻、地肤子、黄连、木贼和胡黄连.大部分中草药浸提液在10倍稀释液条件下对小列当种子发芽的刺激或抑制作用最明显.研究发现,一些参试中草药蒸馏水和甲醇浸提液能够刺激或抑制小列当种子萌发,并且其对种子萌发的影响程度随浸提液浓度的变化而异,不同中草药最佳处理浓度不同,而且用甲醇浸提液可筛选出更多种具有化感作用的中草药.     

Effect of biologically synthesized silver nanoparticles on Bacopa monnieri (Linn.) Wettst. plant growth metabolism

In this present study, interactions of biologically synthesized silver nanoparticles on hydroponically grown Bacopa monnieri (Linn.) Wettst. plant growth metabolism were documented. Estimates of protein, carbohydrate, total phenols, in addition antioxidant enzymes, catalase and peroxidise were assayed in various parts of the plants grown in hydroponic solution. The silver nanoparticles used in this study were synthesized by treating AgNO₃ with aqueous leaves extracts of Acalypha indica Linn., a medicinal herb as a source of reductants. Enhanced peroxidase and catalase activity, simulated the stress conditions induced by the silver nitrate treatment. No severe toxic effects were observed in silver nanoparticles treated plants in the morphological studies under scanning electron microscopy (SEM) while structural aberrations were observed in the light microscopic evaluation of root and stem anatomy. Further, the uptake of silver in the root and stem tissues of B. monnieri (Linn.) Wettst. was confirmed using atomic absorption spectrophotometer (AAS).     

Anti-acetylcholinesterase activities of traditional Chinese medicine for treating Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and cognitive impairment. It is the most common type of dementia in the ageing population due to a severe loss of cholinergic neurons in selected brain area. At present, acetylcholinesterase inhibitors (AChEI) are the first group of drugs approved by the FDA to treat mild to moderate Alzheimer's disease. Most of these drugs such as huperzine and galanthamine are originally isolated from plants. In this study, the AChE inhibitory activities from extracts of Chinese medicinal herbs that have traditionally been prescribed to treat insomnia and brain function disorders were examined in a 96-well plate assay based on Ellman's method. Both ethanol and aqueous extracts of 26 traditional Chinese medicinal herbs were tested. Inhibitory effects were expressed as the percentage of inhibition. For the herbal extracts that were shown to exert a significant inhibition, dose-dependent inhibitory assays were also performed. Ethanol and aqueous extracts of six herbs were found to have high AChE inhibitory activities in a dose-dependent manner. The IC(50) of these herbal extracts on inhibition of AChE are at around 5-85mum/ml. The results of this study indicate that there is a great potential to search for novel usage of these medicinal herbs for the treatment of AD.     

Anti-Helicobacter pylori flavonoids from licorice extract

Licorice is the most used crude drug in Kampo medicines (traditional Chinese medicines modified in Japan). The extract of the medicinal plant is also used as the basis of anti-ulcer medicines for treatment of peptic ulcer. Among the chemical constituents of the plant, glabridin and glabrene (components of Glycyrrhiza glabra), licochalcone A (G. inflata), licoricidin and licoisoflavone B (G. uralensis) exhibited inhibitory activity against the growth of Helicobacter pylori in vitro. These flavonoids also showed anti-H. pylori activity against a clarithromycin (CLAR) and amoxicillin (AMOX)-resistant strain. We also investigated the methanol extract of G. uralensis. From the extract, three new isoflavonoids (3-arylcoumarin, pterocarpan, and isoflavan) with a pyran ring, gancaonols A[bond]C, were isolated together with 15 known flavonoids. Among these compounds, vestitol, licoricone, 1-methoxyphaseollidin and gancaonol C exhibited anti-H. pylori activity against the CLAR and AMOX-resistant strain as well as four CLAR (AMOX)-sensitive strains. Glycyrin, formononetin, isolicoflavonol, glyasperin D, 6,8-diprenylorobol, gancaonin I, dihydrolicoisoflavone A, and gancaonol B possessed weaker anti-H. pylori activity. These compounds may be useful chemopreventive agents for peptic ulcer or gastric cancer in H. pylori-infected individuals.     

27味中药醇提物对酪氨酸酶体外活性的影响

以儿茶酚为底物,体外分光光度法研究了22个科的27味中药醇提物对酪氨酸酶的抑制活性。结果表明,在各种中药的50%乙醇(v/v)提取液中,生药质量浓度达到2 mg/mL时,红花(Carthamus tinctoriusL.)、杨梅叶(Myrica rubraS.)、黄芩(Scutellaria baicalensisG.)和绿茶(Camellia sinensisL.)相对L-抗坏血酸(维生素C)的酪氨酸酶抑制率分别达到128.62%、83.64%、79.65%和66.48%,它们在美白化妆品领域有潜在的应用价值。     

Antimutagenic activity of extracts from anticancer drugs in Chinese medicine

The antimutagenic activities of extracts of 36 commonly used anticancer crude drugs from Chinese herbs were studied by using the Salmonella/microsomal system in the presence of picrolonic acid or benzo[a]pyrene to test whether they contain direct or indirect antimutagens. Each crude drug was extracted with boiling water for 2 h, the method which is commonly used by Chinese people to prepare the drug for oral intake. The extracts of Pteris multifida P. showed the highest antimutagenic activity against picrolonic acid-induced mutation. The extracts of 6 other different kinds of Chinese herbs were shown to have a moderate antimutagenic activity against picrolonic acid-induced mutation, and they are: Actinidia chinensis P., Artemisia lavendulaefolia DC. and Crotalaria sessiflora L., Prunella vulgaris L., Paris polyphylla S. and Ampelopsis brevipedunculata T. The extracts of Smilax china L., Prunella vulgaris L. and Actinidia chinensis P. were demonstrated to inhibit the mutagenicity of benzo[a]pyrene completely. The 12 other kinds of extracts of Chinese herbs which had a moderate antimutagenic activity against benzo[a]pyrene were: Pteris polyphylla S., Ampelopsis brevipedunculata T., Duchesnea indica F., Gossypium herbaceum L., Lithospermum erythrorrhizon SZ., Artemisia lavendulaefolia DC., Selaginella doederleinii H., Dianthus superbus L., Centipeda minima ABA., Curcuma zedoaria R., Marsdenia tenacissima WA. and Kalopanax septemlobus K. Among them, there were 5 kinds of crude drugs, Actinidia chinensis P., Artemisia lavendulaefolia DC., Prunella vulgaris L., Paris polyphylla S. and Ampelopsis brevipedunculata T., containing antimutagenic factors against both picrolonic acid- and benzo[a]pyrene-induced mutation.     

Interaction of folk medicinal plant extracts with human alpha2-adrenoceptor subtypes

Forty-two extracts of folk medicinal plant organs from Pakistan were tested in competition binding assays for their interaction with the specific ligand recognition sites on the human alpha2-adrenoceptor subtypes alpha2A, alpha2B and alpha2C Strong binding of the extracts (40 mg/ml) from Acacia nilotica (L.) Delile leaves (88-98% displacement of radiolabel) and Peganum harmala seeds (89-96% displacement) on three subtypes prompted us to extract these plant materials with 40% and 80% methanol, ethanol, and acetone. The extraction results indicated an absence of alpha2-adrenoceptor binding activity in the stalk of A. nilotica and A. tortils, whereas the leaves of both plants contained activity. The extracts of A. nilotica leaves showed a slight, but consistent, preference for the alpha2C-adrenoceptor, whereas the leaves of A. tortils were slightly more active on the alpha2B subtype. The extract of P. harmala stalks was less active than that of its seeds. The binding activities of A. nilotica leaves and P. harmala seeds were mainly concentrated in the water and 30% methanol fractions and further sub-fractions. In a functional activity assay, the active fractions inhibited epinephrine-stimulated 35S-GTPyS binding, thus indicating a predominantly antagonistic nature of the compounds with alpha2-adrenoceptor affinity in these fractions. Among the known major alkaloids of P. harmala (demissidine, harmaline, harmine, 6-methoxyharmalan, and norharmane), only 6-methoxyharmalan showed moderate affinity (dissociation constant (Ki) of 530 +/- 40 nm for alpha2A subtype). This study is a first systematic attempt towards the discovery of potential drug candidates from these plant materials for treating alpha2-adrenoceptor related diseases.     

Efficacy of leaf extracts of some medicinal plants against disease development in banana

Treatment of infested banana fruits by aqueous leaf extracts of some medicinal plants, viz. Calotropis procera (Ait) R.Br., Vitex negundo Linn., Lantana camara Linn., Azadirachta indica Linn., Ficus religiosa Linn., Ocimum sanctum Lin., Thuja orientalis Linn., Argemone mexicana Linn., Achyranthes aspera Linn., Datura fastuosa Linn. and Ricinus communis Linn. exhibited considerable control of disease development. Of 11 leaf extracts, those of A. indica and O. sanctum were most effective, and showed minimum per cent loss in fruit weight. The appearance of the first disease symptom was also delayed in treated fruits as compared with untreated ones.     

In vitro antimicrobial activity of six medicinal plants traditionally used for the treatment of dysentery and diarrhoea in Democratic Republic of Congo (DRC).

Twenty-four crude extracts derived from six medicinal plants highly valued as antidiarrhoeal agents in Congolese folk medicine were screened for antimicrobial activity against several enteric pathogens. The results of this study indicated that the methanolic and aqueous extracts derived from three of them (Roureopsis obliquifoliolata, Epinetrum villosum and Cissus rubiginosa) possessed prominent antibacterial activity, therefore supporting the ethnomedical uses of these species. In addition, phytochemical analysis of these medicinal plants showed that 1/6 plant sample contained alkaloids, 6/6 triterpenes and/or sterols, 4/6 flavonoids, 3/6 tannins and 5/6 saponins. Anthraquinones were not detected in any of these plants.     

Exploration of the in vitro cytotoxic and antiviral activities of different medicinal plants against infectious bursal disease (IBD) virus

Infectious bursal disease (IBD) caused by non-enveloped double stranded RNA virus is an acute and contagious poultry disease. Outbreak of IBD could result in 10–75% mortality of the birds; hence it has gained socio-economic importance worldwide. Medicinal plants have shown broad spectrum anti-viral activities against RNA and DNA viruses. Moringa oleifera Lam (MOL), Phyllanthus emblicus Linn (PEL), Glycyrrhiza glabra Linn (GGL), and Eugenia jambolana Lam (EJL) are commonly available medicinal plants of the sub-continent and exhibited anti-viral potential against different viruses. Ethanolic extracts of the leaves of MOL and EJL, roots of GGL and dried fruit of PEL were investigated for their cytotoxic and anti-viral potential against IBD virus using MTT colorimetric assay and anti-viral assay. Significant anti-viral potential (P<0.001) was demonstrated at concentrations 12.5, 25, 50 and 100 µg ml^?1 of GGL, PEL, MOL and EJL, respectively, with no cytotoxicity. Data also spotlighted that all tested plant extracts possess significant anti-viral potential and this trend was higher in GGL followed by PEL, MOL, and EJL. The data undoubtedly conclude that these medicinal plants contain several health beneficial phyto-chemicals which got significant anti-viral potential and effectively be utilized against IBD virus. Moreover, the outcomes of this study provide a platform on the way to discover novel anti-viral agents against IBD virus and other viruses from plant origin.     

Anti-Toxoplasma activity of vegetal extracts used in West African traditional medicine

Both Toxoplasma gondii and Plasmodium are Apicomplexan protozoa that share common metabolic pathways and potential drug targets. The objective of this study was to examine the anti-Toxoplasma activity of nine West African plants with known activity against P. falciparum. The extracts were obtained from parts of plant commonly used, by most traditional healers, in the form of infusion or as water decoction. The in vitro activity of plant extracts on T. gondii was assessed on MRC5 tissue cultures and was quantified by enzyme-linked immunoassay. Aqueous extracts from Vernonia colorata were found to be inhibitory for Toxoplasma growth at concentrations > 10 mg/L, with an IC50 of 16.3 mg/L. A ten-fold gain in activity was obtained when organic solvents such as dichloromethane, acetone or ethanol were used to extract V. colorata's active principles. These extracts were inhibitory at concentrations as low as 1 mg/L, with IC50 of 1.7, 2.6 and 2.9 mg/L for dichloromethane, acetone and ethanol extracts respectively. These results indicate a promising source of new anti-Toxoplasma drugs from V. colorata and African medicinal plants.