Egyptian propolis: 1-antimicrobial activity and chemical composition of Upper Egypt propolis

The antimicrobial activity of four propolis samples collected from Upper Egypt against Staphylococcus aureus; Escherichia coli and Candida albicans was evaluated. There was a variation in the antimicrobial activity according to the propolis origin. Banisweif propolis showed the highest antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans, but Fayoum propolis had moderate activity against all tested pathogens. Propolis collected from Assiut and Souhag gave lower antimicrobial activity. Propolis samples were investigated by GC/MS, 71 compounds were identified, 14 being new for propolis. Banisweif propolis is characterized by the presence of 7 caffeate esters and 4 triterpenoids. Fayoum propolis showed the highest amount of lactic acid and the presence of 3 chalcones. But Assiut propolis is characterized by the presence of 4 prenylated coumarates. Souhag propolis is characterized by the presence of 5 aliphatic dicarboxylic acids and some other new compounds to propolis.     

Egyptian propolis: 2. Chemical composition,antiviral and antimicrobial activities of East Nile Delta propolis

Three propolis samples from East Nile Delta, Egypt were collected. Propolis samples were investigated by GC/MS,103 compounds were identified, 20 being new for propolis. Dakahlia propolis was a typical poplar propolis but it contained two new caffeate esters and two new triterpenoids. Ismailia propolis was characterized by the presence of new triterpenic acid methyl esters and it did not contain any aromatic acids, esters and flavonoids. Sharkia propolis was characterized by the presence of caffeate esters only, some di- and triterpenoids. The antiviral (Infectious Bursal Disease Virus and Reo-Virus) and antimicrobial (Staphylococcus aureus; Escherichia coli and Candida albicans) activities of propolis samples were investigated. Dakahlia propolis showed the highest antiviral activity against Infectious Bursal Disease Virus (IBDV) and the highest antibacterial activity against Escherichia coli and the highest antifungal activity against Candida albicans. While Ismailia propolis had the highest antiviral activity against Reo-virus. Sharkia propolis showed the highest antibacterial activity against Staphylococcus aureus and moderate antiviral activity against infectious bursal disease virus and reovirus.     

Egyptian propolis: 3. Antioxidant,antimicrobial activities and chemical composition of propolis from reclaimed lands

The free radical scavenging effect of two propolis samples collected from reclaimed land, Egypt as well as of vitamin C and caffeic acid in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical system was determined. The antimicrobial (Staphylococcus aureus; Escherichia coli and Candida albicans) activity was also investigated. The results of the free radical scavenging effect of El-Saff and Ismailia propolis showed a concentration-dependent activity. The antioxidant activity was varied according to the examined material. It was obvious that caffeic acid and vitamin C showed the highest activity if compared with the propolis samples. El- Saff propolis had a higher antioxidant activity than Ismailia propolis, it showed a higher antibacterial activity against Staphylococcus aureus and a higher anti-fungal activity against Candida albicans. While the Ismailia propolis had a higher antibacterial activity against Escherichia coli, than El-Saff propolis. The chemical composition of propolis samples was investigated by GC/MS, where 75 compounds were identified, 22 being new for propolis. The Ismailia propolis was characterized by the presence of a highly significant amount of aromatic acid esters (47.3%) and triterpenoids (17.3%), while El-Saff propolis contained 3% and 1.9% respectively. The new esters belonged to 4-methoxyhydrocinnamic acid, hydroferulic acid and ferulic acid. El-Saff propolis had a very high significant amount (27%) of 2,6-bis-(pentanyloxy)-4-pentanylphenethanol, which is also a new compound for propolis.     

Chemical compositions and antimicrobial activities of four different Anatolian propolis samples

Propolis means a gum that is gathered by bees from various plants. It is known for its biological properties, having antibacterial, antifungal and healing properties. The aims of this study were to evaluate the antimicrobial activity of four different Anatolian propolis samples on different groups of microorganisms including some oral pathogens and comparison between their chemical compositions. Ethanol extracts of propolis (EEP) were prepared from four different Anatolian propolis samples and examined whether EEP inhibit the growth of the test microorganisms or not. For the antimicrobial activity assays, minimum inhibitory concentrations (MIC) were determined by using macrodilution method. The MIC values of the most effective propolis (TB) were 2 microg/ml for Streptococcus sobrinus and Enterococcus faecalis, 4 microg/ml for Micrococcus luteus, Candida albicans and C. krusei, 8 microg/ml for Streptococcus mutans, Staphylococcus aureus, Staphylococcus epidermidis and Enterobacter aerogenes, 16 microg/ml for Escherichia coli and C. tropicalis and 32 microg/ml for Salmonella typhimurium and Pseudomonas aeruginosa. The chemical compositions of EEP's were determined by high-temperature high-resolution gas chromatography coupled to mass spectrometry. The main compounds of four Anatolian propolis samples were flavonoids such as pinocembrin, pinostropin, isalpinin, pinobanksin, quercetin, naringenin, galangine and chrysin. Although propolis samples were collected from different regions of Anatolia all showed significant antimicrobial activity against the Gram positive bacteria and yeasts. Propolis can prevent dental caries since it demonstrated significant antimicrobial activity against the microorganisms such as Streptococcus mutans, Streptococcus sobrinus and C. albicans, which involves in oral diseases.     

Antimicrobial and antiviral screening of novel indole carboxamide and propanamide derivatives

A few series of indole derivatives were screened for antimicrobial, antifungal and anti-HBV activities. The compounds were tested for their in vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and for their antifungal activity against Candida albicans using a disc diffusion method, which measures the diameter of the inhibition zone around a paper disc soaked in a solution of the test compounds. The antimicrobial activity results showed that all compounds are as a active as the standard compound ampicillin against Staphylococcus aureus. It was also found that indole carboxamide derivatives, substituted at 3-position with several benzyl groups, showed better inhibition of Bacillus subtilis than their congeners substituted at 2-position. Activity patterns of the compounds against Escherichia coli and Staphylococcus aureus were found slightly different by the same method. In this case, there was no correlation between structure and activity of the compounds. The antifungal activity of carboxamide derivatives was found higher compared to that of the propanamide derivatives. The minimum inhibitory concentration (MIC) values of some indole derivatives were also determined by the tube dilution technique. The MIC values of the compounds were found nearly 20- to 100-fold smaller compared to the standard compounds ciprofloxacin and ampicillin (1.56-3.13 microg/ml and 1.56-12.5 microg/ml, respectively) against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. The MIC values of the tested compounds showed that these are better inhibitors for Candida albicans. Indole derivatives were screened by the anti-HBV susceptibility test. No compound showed good inhibition against the HBV virus.     

Biological activities from extracts of endophytic fungi isolated from Viguiera arenaria and Tithonia diversifolia

A total of 39 endophytic fungi have been isolated from Viguiera arenaria and Tithonia diversifolia, both collected in S?o Paulo State, Brazil. The isolates were identified based on their ribosomal DNA sequences. The ethyl acetate (EtOAc) extracts of all endophytic fungi were evaluated for their antimicrobial, antiparasitic and antitumoral activity. Antimicrobial screening was conducted using an agar diffusion assay against three pathogenic microorganisms: Staphylococcus aureus, Escherichia coli and Candida albicans. Antiparasitic activity was determined by enzymatic inhibition of gGAPDH of Trypanosoma cruzi and adenine phosphorybosiltransferase (APRT) of Leishmania tarentolae. Antitumoral activity was tested against human T leukemia cells by the Mosmann colorimetric method. All extracts showed activity in at least one assay: 79.5% of the extracts were cytotoxic against leukemia cells, 5.1% of the extracts were active against S. aureus, 25.6% against E. coli and 64.1% against Candida albicans. Only one extract showed promising results in the inhibition of parasitic enzymes gGAPDH (95.0%) and three were found to inhibit APRT activity. The cytotoxic extract produced by the strain VA1 (Glomerella cingulata) was fractionated and yielded nectriapyrone and tyrosol. Nectriapyrone showed relevant cytotoxic activity against both human T leukemia and melanoma tumor cell lines.     

Bioactivity studies of extracts from Tridax procumbens.

An updated review on the biological activity of Tridax procumbens is presented. A detailed biological screening comprised of gram-positive and gram-negative bacteria, yeasts and fungi using crude extracts of this plant was undertaken. The n-hexane extract of the flowers showed activity against Escherichia coli. The same extract of the whole aerial parts was active against Mycobacterium smegmatis, Escherichia coli, Salmonella group C and Salmonella paratyphi. The ethyl-acetate extract of the flowers was active against Bacillus cereus and Klebsiella sp. The aerial parts extract also showed activity only against Mycobacterium smegmatis and Staphylococcus aureus, while the aqueous extract showed no antimicrobial activity. None of the tested extracts was active against the yeasts, Candida albicans, Candida tropicalis and Rhodotorula rubra; or the fungi: Aspergillus flavus, Aspergillus niger, Mucor sp. and Trichophyton rubrum.     

Investigation and identification of the antimicrobial component of the drug "Tomatol"]

Antimicrobial activity of Tomatol against laboratory strains of Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538-P and Candida albicans ATCC 885-653 as well as against clinical isolates of Enterobacter spp., Streptococcus spp., Staphylococcus spp., Klebsiella spp. and Escherichia spp. was tested. Tomatol was shown to have a broad antimicrobial spectrum including gram-positive and gram-negative organisms and Candida. The TLC investigation demonstrated that the Tomatol antimicrobial component was that of a complex of organic acids such as succinic, citric, tartaric and others.     

Antimicrobial activity of some Salvia species essential oils from Iran

The aerial parts of Salvia multicaulis, S. sclarea and S. verticillata were collected at full flowering stage. The essential oils were isolated by hydrodistillation and analyzed by combination of capillary GC and GC-MS. The in vitro antimicrobial activity of the essential oils were studied against eight Gram-positive and Gram-negative bacteria (Bacillus subtilis, Bacillus pumulis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) and three fungi (Candida albicans, Saccharomyces cerevisiae and Aspergillus niger). The results of antibacterial activity tests of the essential oils according to the disc diffusion method and MIC values indicated that all the samples have moderate to high inhibitory activity against the tested bacteria except for P. aeruginosa which was totally resistant. In contrast to antibacterial activity, the oils exhibited no or slight antifungal property, in which only the oil of S. multicaulis showed weak activity against two tested yeasts, C. albicans and S. cerevisiae.     

Chemical composition and biological activity of propolis from Brazilian meliponinae

Twenty-one propolis samples produced by 12 different Meliponinae species were analyzed by GC-MS. Several chemical types of stingless bees' propolis could be grouped, according to the prevailing type of compounds like: 'gallic acid", "diterpenic" and "triterpenic" types. The results confirm that neither the bee species nor the geographical location determine the chemical composition of Meliponinae propolis and the choice of its plant source, respectively. This could be explained by the fact that Meliponinae forage over short distances (maximum 500 m) and thus use as propolis source the first plant exudate they encounter during their flights. The antibacterial, antifungal and cytotoxic activities of the samples were also investigated. Most samples had weak or no activity against E. coli, weak action against Candida albicans. Some of them showed significant activity against St. aureus., presumably connected to the high concentration of diterpenic acids. Samples rich in diterpenic acids possessed also high cytotoxic activity (Artemia salina test).     

The antimicrobial activity of extracts of the lichen Hypogymnia tubulosa and its 3-hydroxyphysodic acid constituent

The antimicrobial activity and the MIC values of the diethyl ether, acetone, chloroform, petroleum ether, and ethanol extracts of the lichen Hypogymnia tubulosa and its 3-hydroxyphysodic acid constituent have been investigated against some microorganisms. At least one of the extracts or 3-hydroxyphysodic acid showed antimicrobial activity against Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Proteus vulgaris, Salmonella typhimurium, Staphylococcus aureus, Streptococcus faecalis, and Candida albicans. No antifungal activity of the extracts has been observed against ten filamentous fungi.     

In vitro anti-microbial activity of the Cuban medicinal plants Simarouba glauca DC, Melaleuca leucadendron L and Artemisia absinthium L

In the present study, an extensive in vitro antimicrobial profiling was performed for three medicinal plants grown in Cuba, namely Simarouba glauca, Melaleuca leucadendron and Artemisia absinthium. Ethanol extracts were tested for their antiprotozoal potential against Trypanosoma b. brucei, Trypanosoma cruzi, Leishmania infantum and Plasmodium falciparum. Antifungal activities were evaluated against Microsporum canis and Candida albicans whereas Escherichia coli and Staphylococcus aureus were used as test organisms for antibacterial activity. Cytotoxicity was assessed against human MRC-5 cells. Only M. leucadendron extract showed selective activity against microorganisms tested. Although S. glauca exhibited strong activity against all protozoa, it must be considered non-specific. The value of integrated evaluation of extracts with particular reference to selectivity is discussed.     

Chitosan�CEDTA New Combination is a Promising Candidate for Treatment of Bacterial and Fungal Infections

Chitosan is an attractive preparation widely used as a pharmaceutical excipient. This study aimed to evaluate the antimicrobial activities of chitosan derivatives, EDTA, and the newly developed chitosan-EDTA combination against Gram-negative and Gram-positive bacteria as well as Candida albicans. Antimicrobial activity was studied. Both minimal Inhibitory Concentrations (MIC) and minimal biocidal concentrations (MBC) were determined. Chitosan acetic acid recorded lower MIC values against Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans than those exhibited by EDTA. EDTA failed to have inhibitory activity against Enterococcus faecalis as well as MBC against any of the studied microorganisms. Chitosan acetic acid's MBC were recorded to all examined species. Checkerboard assay results indicated a synergistic antimicrobial activity of the new combination against Staphylococcus aureus and an additive effect against other microorganisms. Moreover, a short microbial exposure to chitosan-EDTA (20-30 min) caused complete eradication. Due to the continuous emergence of resistant strains, there is an urgent need to discover new antimicrobial agents. Our findings suggest the use of chitosan as an enhancing agent with antibacterial and antifungal properties in combination with EDTA in pharmaceutical preparations.     

Antimicrobial activity of essential oils and other plant extracts

The antimicrobial activity of plant oils and extracts has been recognized for many years. However, few investigations have compared large numbers of oils and extracts using methods that are directly comparable. In the present study, 52 plant oils and extracts were investigated for activity against Acinetobacter baumanii, Aeromonas veronii biogroup sobria, Candida albicans, Enterococcus faecalis, Escherichia col, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica subsp. enterica serotype typhimurium, Serratia marcescens and Staphylococcus aureus, using an agar dilution method. Lemongrass, oregano and bay inhibited all organisms at concentrations of < or = 2.0% (v/v). Six oils did not inhibit any organisms at the highest concentration, which was 2.0% (v/v) oil for apricot kernel, evening primrose, macadamia, pumpkin, sage and sweet almond. Variable activity was recorded for the remaining oils. Twenty of the plant oils and extracts were investigated, using a broth microdilution method, for activity against C. albicans, Staph. aureus and E. coli. The lowest minimum inhibitory concentrations were 0.03% (v/v) thyme oil against C. albicans and E. coli and 0.008% (v/v) vetiver oil against Staph. aureus. These results support the notion that plant essential oils and extracts may have a role as pharmaceuticals and preservatives.     

Anti-inflammatory, antioxidant and antimicrobial activity of Ophthacare brand, an herbal eye drops.

In the present study, the herbal preparation of Ophthacare brand eye drops was investigated for its anti-inflammatory, antioxidant and antimicrobial activity, using in vivo and in vitro experimental models. Ophthacare brand eye drops exhibited significant anti-inflammatory activity in turpentine liniment-induced ocular inflammation in rabbits. The preparation dose-dependently inhibited ferric chloride-induced lipid peroxidation in vitro and also showed significant antibacterial activity against Escherichia coli and Staphylococcus aureus and antifungal activity against Candida albicans. All these findings suggest that Ophthacare brand eye drops can be used in the treatment of various ophthalmic disorders.     

Synthesis of egonol derivatives and their antimicrobial activities

Eighteen derivatives of egonol (A-R) were synthesized and evaluated for their antimicrobial activities against Staphylococcus aureus ATCC 29213, Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231 and Escherichia coli ATCC 8739 microorganisms comparing with egonol. The obtained data reported that compound B exhibited improved activities against all tested bacteria than egonol, others have shown different range of activities.     

Antimicrobial activity of extracts of chemical races of the lichen Pseudevernia furfuracea and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents

The antimicrobial activity and the MIC values of the ethanol, chloroform, diethyl ether, and acetone extracts of the chemical races of Pseudevernia furfuracea (var. furfuracea and var. ceratea) and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents have been investigated against some microorganisms. Nearly all extracts of both chemical races showed antimicrobial activity against Aeromonas hydrophila, Bacillus cereus, Bacillus subtilis, Listeria monocytogenes, Proteus vulgaris, Staphylococcus aureus, Streptococcus faecalis, Yersinia enterocolitica, Candida albicans, Candida glabrata, Alternaria alternata, Ascochyta rabiei, Aspergillus niger, Fusarium culmorum, Fusarium moniliforme, Fusarium oxysporum, Fusarium solani, and Penicillium notatum. There was no antimicrobial activity of the extracts against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Pseudomonas syringae, Salmonella typhimurium, Alternaria citri, Alternaria tenuissima, and Gaeumannomyces graminis. Chloroatranorin and olivetoric acid were active against the same microorganisms with few exceptions. Physodic acid was active against about the same bacteria and yeasts and inactive against all of the filamentous fungi tested. Also no activity of atranorin against the filamentous fungi was observed.     

Synthesis and antimicrobial properties of novel silver/polyrhodanine nanofibers

Silver nanoparticle-embedded polyrhodanine nanofibers were synthesized by chemical oxidation polymerization. Silver ions were reduced to silver nanoparticles by oxidizing rhodanine monomer and simultaneously complexed with the rhodanine due to coordinative interactions, resulting in the formation of silver nanoparticle-embedded polyrhodanine nanofibers. The synthesized silver/polyrhodanine nanofiber was found to have the excellent antimicrobial activity against gram-negative Escherichia coli, gram-positive Staphylococcus aureus, and Candida albicans. The modified Kirby-Bauer test demonstrated that the silver/polyrhodanine nanofiber had better antimicrobial efficacy than silver sulfadiazine.     

The lactoperoxidase system: the influence of iodide and the chemical and antimicrobial stability over the period of about 18 months

The lactoperoxidase (LP) system is a natural antimicrobial system, the use of which has been suggested as a preservative in foods and pharmaceuticals. The effect of adding iodide to the LP system, the chemical stability and the change in antimicrobial effectiveness during storage was studied. Addition of iodide with thiocyanate increased the fungicidal and bactericidal effect against Candida albicans, Escherichia coli and Staphylococcus aureus. Pseudomonas aeruginosa showed the same inhibition in the LP system with iodide and without iodide. Storage of the LP system in completely filled airtight containers for 18 months caused a 35% loss of the initial thiocyanate concentration. The antimicrobial activity of this LP system was strong enough to kill inocula of 106 cfu ml-1 of the four test organisms within 2 h of contact time. During storage of the air-containing LP system, the concentration of thiocyanate was reduced below detection limit within 7 d, the concentrations of hypothiocyanite and hypoiodite within 350 d. After 516 d the antimicrobial activity of air-containing LP system was strong enough to kill inocula of 106 cfu ml-1 Ps. aeruginosa within 2 h, Staph. aureus within 4 h and Candida albicans and E. coli within 1 week of contact time.     

26种滇产植物提取物的体外抗耐药菌作用研究

研究26种云南滇东南产植物80%乙醇提取物的体外抗耐药菌作用。制备植物的醇提物,用琼脂打孔法对其进行抗菌活性的筛选。通过微量稀释法测定提取物的最低抑菌浓度[minimum inhibitory concentration(MIC)]、最低杀细菌浓度[minimum bactericidal concentration(MBC)]及最低杀真菌浓度[minimum fungicidal concentration(MFC)]。结果表明:26种提取物中有9种对金黄色葡萄球菌(简称金葡菌)、大肠埃希菌、铜绿假单胞菌、白色念珠菌有不同程度的抑制活性;其中以红花荷、马蹄参、百花贝母兰、二色大包兰和光序肉实树提取物对耐甲氧西林金葡菌的抑菌作用最强,其MIC/MBC(mg/L)范围分别为512/2048～>2048,512/2048～>2048,256-512/2048～>2048,512～1024/1024～>2048和512～1024/>2048。另外,肋果茶提取物对铜绿假单胞菌及白色念珠菌有较好的抑制作用,其对铜绿假单胞菌及其耐药菌株的MIC/MBC为512～2048/>2048mg/L;对白色念珠菌及其耐药菌株的MIC/MFC均为2048/>2048mg/L。26种植物提取物对大肠埃希菌的抑制作用均较弱。