Antibacterial Activity Of Fractions Research Articles

Antibacterial activity and antioxidant capacity of dairy kefir beverages

Kefir traditionally is based on pasteurised milk and the use of other substrates is unusual. Kefir beverages made with raw milk (RMK), pasteurised milk (PMK) or whey (WK), were obtained and fractionated in microbial cells and supernatants. Antioxidant and antibacterial activity of fractions against Cronobacter sakazakii and Escherichia coli were analysed. The highest antioxidant activity was obtained for PMK with values between 8500 and 10 000 μm TE/mg. Microbial extracts from RMK and PMK showed a reduction of C. sakazakii of 7 log units; while microbial extracts and supernatants from RMK decreased E. coli in 3 and 5 log units, respectively. These results indicate that dairy kefir beverages can be an excellent source of defensive agents to fight against bacteria that cause gastrointestinal disorders.

Phenolic Content, Antioxidant Potential, and Antimicrobial Activity of Uvaria chamae (Annonaceae), a Food Plant from Burkina Faso.

The study aimed to evaluate phenolic content and antioxidant and antibacterial potentials of the fractions of the hydroethanolic extract of Uvaria chamae leaves, a food plant from Burkina Faso. Thus, the hexane, dichloromethane, ethyl acetate, and butanol fractions of the hydroalcoholic extract after drying were used to determine phenolic compound content, antioxidant activity, and antimicrobial potential on strains of pathogenic bacteria responsible for food contamination. Phytochemical analyses were performed according to standardized methods, while antioxidant activity was evaluated by DPPH and FRAP methods. The antibacterial activity of the fractions was determined by diffusion and microdilution methods on the agar medium with gentamicin as a reference antibiotic. All the six strains, namely, Salmonella typhi ATCC 19430, Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 9027, Bacillus cereus ATCC 13061, and Listeria monocytogenes ATCC 7644, were sensitive to the fractions tested. Minimum inhibitory concentrations ranged from 37 µg·mL-1 to 1.67 mg·mL-1, respectively, gentamicin and butanolic fractions, while minimum bactericidal concentrations of the fractions ranged from 0.037 to 2.500 mg·mL-1 depending on the bacterial strain. Antioxidant activity varied significantly between fractions. For DPPH free radical scavenging activity, the butanol fraction was the most active, with an IC50 of 280 μg/mL, while the lowest activity (705 μg/mL) was recorded by the hexane fraction. Those of trolox and ascorbic acid used as standards were 80 and 100 μg/mL, respectively. Ferric reducing power (FRAP) ranged from 0.34 to 0.40 mmol EAA/g extract for the hexanic and ethyl acetate fractions, respectively. Phenolic compound contents also varied significantly between fractions. Butanoic and ethyl acetate presented the best contents of total phenolics and flavonoids, respectively. Significant and positive correlations were also recorded between phenolics and antioxidant activities. The antibacterial and antioxidant activities of the active fractions would be related to their richness in bioactive compounds, including phenolic, which are powerful natural antioxidants. U. chamae leaf extracts could therefore be used as dietary supplements to boost the immune system and prevent bacterial infections.

ANTIBACTERIAL ACTIVITY OF FRACTIONS FROM ETHANOLIC EXTRACT OF HYLOCEREUS

"Antibacterial Activity of Fractions from Ethanolic Extract of Hylocereus." In this investigation, fractions derived from the ethanolic extract of Hylocereus, a genus of cacti commonly known as dragon fruit, were evaluated for their antibacterial properties. The study aimed to assess the potential of these fractions in inhibiting the growth of bacterial pathogens. The extraction process involved the isolation of bioactive compounds from the plant material, and the antibacterial activity was determined through rigorous laboratory testing. The results revealed promising antibacterial effects, suggesting that the fractions derived from the ethanolic extract of Hylocereus may serve as valuable resources for the development of novel antimicrobial agents. This research contributes to the understanding of the therapeutic potential of plant-based compounds in combating bacterial infections. "Antibacterial Activity of Fractions from Ethanolic Extract of Hylocereus." In this investigation, fractions derived from the ethanolic extract of Hylocereus, a genus of cacti commonly known as dragon fruit, were evaluated for their antibacterial properties. The study aimed to assess the potential of these fractions in inhibiting the growth of bacterial pathogens. The extraction process involved the isolation of bioactive compounds from the plant material, and the antibacterial activity was determined through rigorous laboratory testing. The results revealed promising antibacterial effects, suggesting that the fractions derived from the ethanolic extract of Hylocereus may serve as valuable resources for the development of novel antimicrobial agents. This research contributes to the understanding of the therapeutic potential of plant-based compounds in combating bacterial infections.

Antibacterial Activity of Water, Ethyl Acetate and n-Hexane Fractions of Pagoda leaves (Clerodendrum paniculatum L.) against Propionibacterium acnes

Pagoda plant (Clerodendrum paniculatum L.) is a medicinal plant that is widely distributed in ASEAN countries, including Indonesia. Pagoda plants are believed to have good pharmacological activity. In this study, the antibacterial activity of pagoda leaves was tested against Propionibacterium acnes. The method used in this research is the antibacterial activity test utilizing agar diffusion using paper discs to assess the inhibitory power of the test substance. The test groups used were water, ethyl acetate, and n-hexane fractions, with each divided into concentrations of 1, 3, 5, 10, 15, and 20%. The positive control used was Clindamycin, and the negative control used was dimethyl sulfoxide solution (DMSO). The results obtained with the highest inhibition value were clindamycin with an inhibition diameter of 28.70+0.15mm, then by a water fraction of 20% with an inhibitory diameter of 14.20+0.20mm. The study results concluded that the antibacterial activity of each fraction of the pagoda leaves was not vigorous in inhibiting the growth of Propionibacterium acnes bacteria.

Antibacterial Activity of Fractions from Extract Ethanolic of Hylocereus Polyrhizus Peel Against E. Coli and S. aureus

Peel of red dragon fruit (Hylocereus polyrhizus) is one of the plants used as an antibacterial agent as it contains saponin triterpenoid compounds, flavonoid compounds, and alkaloid compounds which can have antibacterial activity. This research aims to determine the antibacterial effect of n-hexane, ethyl acetate, and ethanol fraction of red dragon fruit’s peel against Escherichia coli and Staphylococcus aureus by the concentration of 10mg/ml, 20mg/ml, 40mg/ml, 80mg/ml dan 160mg/ml. This research was conducted by using laboratory experiments. The simplicia was macerated with 96% ethanol and fractionated by n-hexane and ethyl acetate. The phytochemical screening of the fraction was n-hexane fraction containing saponin and alkaloid, while the ethyl acetate fraction contained saponin and flavonoid. Kanamycin was used as a positive control, while DMSO was used as a negative control. According to this research, the MIC value of ethanol fraction, n-hexane fraction, and ethyl acetate fraction were 80mg/ml, 20mg/ml, and 80mg/ml, respectively, for E. coli and all fractions were 10mg/ml for S. aureus. Based on the average diameter of the inhibition zone, the largest diameter zone in E. coli was ethyl acetate fraction with 160mg/ml concentration that was 10,33mm. Meanwhile, in S. aureus n-hexane fraction, it was 160mg/ml, which was 11,20mm. This result showed that the n-hexane fraction has good gram-positive activity while the ethyl acetate fraction has good activity on gram-negative.

Antibacterial activity of fractions (chloroform, ethyl acetate and methanol) red betel leaf ethanol extract (Piper crocatum) against Streptococcus pyogenes bacteria

Antibacterial activity of fractions (chloroform, ethyl acetate and methanol) red betel leaf ethanol extract (Piper crocatum) against Streptococcus pyogenes bacteria

The anti-Staphylococcus aureus activity of the phenanthrene fraction from fibrous roots of Bletilla striata.

BackgroundBletillae Rhizoma, the tuber of Bletilla striata, has been used in Chinese traditional medicine to treat infectious diseases. Chemical studies indicated that phenanthrene was one of the most important components of the herb, with a broad spectrum of antibiotic activity against Gram-positive bacteria. The objective of this study was to further characterize the antibacterial activity of the phenanthrene fraction from the fibrous root of the pseudobulb of B. striata.MethodsThe phenanthrene fraction (EF60) from the ethanol extract of fibrous roots of Bletilla striata pseudobulbs was isolated using polyamide column chromatography. The antibacterial activity of the fraction was evaluated in vitro using a 96-well microtiter plate and microbroth dilution method. The cytotoxicity of EF60 against mammalian cells was tested by hemolysis and MTT assays.ResultsEF60 was obtained using alcohol extraction and polyamide column chromatography, with a yield of 14.9 g per 1 kg of the fibrous roots of B. striata. In vitro tests indicated that EF60 was active against all tested strains of Staphylococcus aureus, including clinical isolates and methicillin-resistant S. aureus (MRSA). The minimum inhibitory concentration (MIC) values of EF60 against these pathogens ranged from 8 to 64 μg/mL. Minimum bactericidal concentration tests demonstrated that EF60 was bactericidal against S. aureus 3304 and ATCC 29213 and was bacteriostatic against S. aureus 3211, ATCC 25923, and ATCC 43300. Consistently, the time-kill assay indicated that EF60 could completely kill S. aureus ATCC 29213 at 2× the MIC within 3 h but could kill less than two logarithmic units of ATCC 43300, even at 4× the MIC within 24 h. The postantibiotic effects (PAE) of EF60 (4× MIC) against strains 29213 and 43300 were 2.0 and 0.38 h, respectively. Further studies indicated that EF60 (160 μg/mL) showed no cytotoxicity against human erythrocytes, and was minimally toxic to Human Umbilical Vein Endothelial Cells with an IC50 of 75 μg/mL.ConclusionsOur studies indicated that EF60 is worthy of further investigation as a potential phytotherapeutic agent for treating infections caused by S. aureus and MRSA.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-016-1488-z) contains supplementary material, which is available to authorized users.

Antibacterial activity of fractions from three Chumash medicinal plant extracts and in vitro inhibition of the enzyme enoyl reductase by the flavonoid jaceosidin

We have investigated the in vitro antibacterial bioactivity of dichloromethane-soluble fractions of Artemisia californica, Trichostema lanatum, Salvia apiana, Sambucus nigra ssp. cerulea and Quercus agrifolia Née against a ΔtolC mutant strain of Escherichia coli. These plants are traditional medicinal plants of the Chumash American Indians of Southern California. Bioassay-guided fractionation led to the isolation of three flavonoid compounds from A. californica: jaceosidin (1), jaceidin (2), and chrysoplenol B (3). Compounds 1 and 2 exhibited antibacterial activity against E. coli ΔtolC in liquid cultures. The in vitro activity of 1 against the enoyl reductase enzyme (FabI) was measured using a spectrophotometric assay and found to completely inhibit FabI activity at a concentration of 100 μM. However, comparison of minimum inhibitory concentration values for 1–3 against E. coli ΔtolC and an equivalent strain containing a plasmid constitutively expressing fabI did not reveal any selectivity for FabI in vivo.

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.

GC-MS analysis and antibacterial activity of some fractions from Lagochilus ilicifolius Bge. grown in Mongolia

3-methyl-1,2,3,4-tetrahydroquinoline (1), 4-hydroxyisoquinoline (2), 4-(1E)-hydroxy-1-prophenyl)-2-methoxyphenol (3), 4-acetoxycinnamic acid (4), Songoramine (5), and Songorine (6) have been determined by GC-MS analysis from the crude alkaloid mixtures (G1) obtained from the aerial parts of Lagochilus ilicifolius Bge. grown in Mongolia and comparison of the measured data with those from the literature. The compounds 1-6 are described for the first time from L.ilicifolius. From these 3-methyl-1,2,3,4-tetrahydroquinoline (1) was determined for the first time from natural plants.In addition, the antibacterial activity of fractions and total alkaloids were evaluated against Staphylococcus aurous, Bacillus subtilis, Bacillus cereus and Escherichia coli strains, respectively. The growth inhibition zones against gram-positive S.aureus, B.subtilis, B.cereus and gram negative E.coli, strains were observed. Positive results were achieved on 500 μg/disc concentration, but lower results or no active on 100 μg/disc concentration were for the plant extracts, fractions and total alkaloids.Mongolian Journal of Chemistry 16 (42), 2015, 39-43

Antibacterial, antioxidant activities and phytochemical analysis of the leaf extract of Ludwigia grandiflora spp., invasive

Introduced from South America in the 19th century as an ornamental aquatic plant, Ludwigia has since invaded almost every continent. L. grandiflora is widespread and invasive in France, forming dense aquatic stands, which cause major ecological and economic problems and reduce local biodiversity. The eradication of L. grandiflora is either very difficult or even impossible. The purpose of this study was the valorization of potential antibacterial and antioxidant compounds in the leaf extract of L. grandiflora using a bioassay-guided fractionation approach. Antibacterial activity was assessed using the disc diffusion and microdilution methods against 14 strains of Gram-positive and Gram-negative bacteria. Crude methanolic leaf extract showed strong activity against most of the tested strains, sometimes being more active than common antibiotics. Maximum antibacterial activity was measured against two pathogenic bacteria, Staphylococcus aureus and Salmonella enterica. The bioassay guided fractionation led to the isolation of several fractions more active than the crude extract; antibacterial activity of fraction (A) was 52% higher than that of the crude extract against S. aureus. The antioxidant activity was evaluated by the scavenging effect on DPPH (2,2-diphenyl-1-picrylhydrazyl) and was expressed as EC50 (µg/mL), the extract dose required to cause a 50% inhibition. The fraction (A) exhibited a higher antioxidant activity (EC50= 6 µg/mL), as compared to the crude extract (EC50= 26.3 µg/mL) and the Trolox (EC50= 15.9 µg/mL), which was used as reference standard. RP-HPLC analysis showed that myricetin was the major phenolic compound. However, there was insufficient time to determine the active molecules. This innovative study, which allowed the submission of a patent, suggests that Ludwigia may be considered as an interesting source of antibacterial and antioxidant compounds for therapeutic uses and for the cosmetic and nutraceutical industries.

Antioxidative and Antibacterial Activities of Artemisia princeps Pampanini Extracts

In the present study, the antioxidative and antibacterial activities of Artemisia princeps Pampanini (A. princeps Pamp.) extract were investigated. The ethyl acetate fraction of A. princeps Pamp. showed the most prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity (). Reactive oxygen species (ROS) scavenging activities () of A. princeps Pamp. extract on systems were investigated using a luminol-dependent chemiluminescence assay. The ethyl acetate fraction of the extract () had a 5 times greater ROS scavenging activity than L-ascorbic acid (), known as a water soluble antioxidant. The cellular protective effects of fractions of A. princeps Pamp. on the rose-bengal sensitized photohemolysis of human erythrocytes were examined. The aglycone fraction of extracts suppressed photohemolysis in a concentration dependent manner. The inhibitory effects of A. princeps Pamp. extract on tyrosinase were investigated to assess their whitening efficiency. The ethyl acetate fraction demonstrated a 7 times higher tyrosinase inhibitory effect () than albutin, known as a whitening agent. The antibacterial activity of ethyl acetate fractions against various normal skin flora were measured. The results showed that the antibacterial activity of the fraction was the highest on Staphylococcus aureus, Bacillus subtilis, and Propionibacterium acnes. Antioxidant substances were isolated and purified from the ethyl acetate fractions. Eupatilin and jaceosidin were identified. These results indicate that the extract/fractions of A. princeps Pamp. can function as antioxidant and/or antibacterial agents for the skin.

AVALIAÇÃO DA ATIVIDADE ANTIBACTERIANA DE Aster lanceolatus Willd. (ASTERACEAE) CONTRA Staphylococcus aureus

Utilizando o método de bioautografia, avaliou-se a atividade antibacteriana de frações de Aster lanceolatus Willd contra cepas de Staphylococcus aureus. Os resultados demonstraram que a fração hexano e fração diclorometano apresentam atividade antibacteriana contra o microrganismo testado.