Antimicrobial Activity Of Aqueous Extracts Research Articles

Bioaccessibility of the bioactive compounds and antimicrobial activity of aqueous extracts of Physalis angulata L.

Plant diversity around the world, as well as the chemical variation, involves a large amount of bioactive substances. The use of plant extracts with biological properties appears as a viable and healthy alternative when compared to synthetic substances. In this context, the objective of this study was to evaluate the aqueous extracts of native and cultivated leaves of Physalis angulata L., as well as the influence of the extraction method on the bioaccessibility of bioactive compounds, antioxidant activity and antimicrobial activity. The extracts were obtained from the native and cultivated leaves of P. angulata using three different extraction methods: decoction, maceration and an ultrasound-assisted method. The analysis of variance showed significant differences between the extraction methods and the type of plant material. The extracts obtained by decoction showed the highest levels of phenolic compounds and higher antioxidant potential for both analytical methods (ABTS and DPPH), differing significantly from the other extraction methods. The bioaccessibility indices of the phenolic compounds obtained from the extracts were considered reduced after the simulated gastrointestinal digestion, and consequently, showed low antioxidant potential. The antimicrobial potential of the extracts was observed against the Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes.

In vitro anti-Helicobacter pylori activity of aqueous extract from Persian Oak testa

ObjectiveGrowing problem of antibiotic resistance in Helicobacter pylori, as a common cause of chronic gastritis and even stomach cancer, demands searching for novel candidates of herbal sources. This study is aimed at assessing the antimicrobial activity of aqueous extract obtained from Quercus brantii var. persica seed coat (Testa) on H. pylori isolated from gastric biopsy specimens. MethodsSuch specimens were collected from 100 patients presenting with endoscopic gastroduodenal findings. Testa extracts were prepared from Persian Oak forests in the province of Kohgiluyeh and Boyer-Ahmad, IRAN. H. pylori isolates were obtained by a series of standard bacteriology tests and cell culture, then were confirmed by PCR. The activity of testa extracts towards 25 H. pylori isolates was assessed by well diffusion method, microdilution assay, and a disk diffusion assay in vitro. Results were analyzed statistically by one-way ANOVA analysis. ResultsAqueous extract of testa demonstrated an antimicrobial activity with zone diameters of inhibition ranged from 0 mm to 40 mm. Its inhibitory activity increased simultaneously with increasing extract concentration. The lowest MIC and MBC were both recorded as 2 µg/mL. Anti-H. pylori activity of testa extract was approximately close to tetracycline and metronidazole and less than amoxicillin. A potent extract of testa possessed significant inhibitory activity (P < 0.05). ConclusionTesta extract is suggested as a natural therapeutic source against the gastric H. pylori infection. However, evaluating the in vivo activity of this extract is necessary too.

Evaluation of antimicrobial activity of Pterocarpus extracts

Pterocarpus is one of the most widely used timber resources on the market. But the utilization rate has been low. In order to improve the utilization of Pterocarpus processing residue, as well as explore the reason of its good decay-resistance. In this study, the antifungal mechanism of Peterocarpes spp., aqueous extracts and ethanol extracts of three Pterocarpus species were studied. The antimicrobial active factors were analyzed by gas chromatography-mass spectrometry. Italian poplar (Populus euramevicana cv. ‘I-214’) wood was immersed in the extracts and then inoculated with both Coriolus versicolor and Gloeophyllum trabeum. The antimicrobial properties of the extracts were studied, and the mechanism underlying these properties were analyzed using gas chromatography-mass spectrometry. The results showed that the yield of ethanol extracts from the three Pterocarpus species was significantly higher than that of aqueous extracts. Pterocarpus soyauxii and Pterocarpus macarocarpus produced the highest yield of ethanol extracts (28.59%) and aqueous extracts (14.31%), respectively. With increasing concentrations, the antimicrobial activities of aqueous extracts of Pterocarpus angolensis and Pterocarpus macarocarpus gradually increased, while the antimicrobial activity of other extracts remained constant. Gas chromatography-mass spectrometry analysis identified a considerable number of phenols, ketones, amines, and aromatic compounds in all extracts, which is consistent with their antimicrobial activity and suggests synergism among the chemicals.

Antioxidant, antihypertensive, anti-hyperglycemic, and antimicrobial activity of aqueous extracts from twelve native plants of the Yucatan coast.

Looking for a biotechnical potential, aqueous extracts of leaves of 12 native species used in the Mayan traditional medicine of the coastal dune and mangrove of Yucatan (Mexico) were selected to evaluate their biological activities. Rhizophora mangle and Manilkara zapota showed the highest free radical scavenging activity (3.94 ± 0.19 and 6.42 ± 0.32 μg/mL, respectively), and the highest antihypertensive activity was obtained from Solanum donianum (0.38 μg/mL). The anti-hyperglycemic activity of these species was also tested; the highest activities were registered with R. mangle. The antimicrobial activity of Malvaviscus arboreus, S. donianum, M. zapota, and R. mangle at 10% (w/v) was positive against six human pathogenic bacteria and Bonellia macrocarpa against one pathogenic fungus. Solanum donianum, M. zapota, B. macrocarpa, and R. mangle were positive against two pathogenic plant fungi. These results show that the aqueous extracts of five native plants of the Yucatan coast have potential as antioxidants, ACE inhibitors, α-amylase and α-glucosidase inhibitors, and as antimicrobials, which make their exploration for utilization in the agricultural and pharmaceutical industries a possibility.

PHYTOCHEMICAL SCREENING, ANTIMICROBIAL, AND ANTIOXIDANT ACTIVITIES OF ROOT AND LEAF EXTRACTS OF LEUCAS ASPERA

Objective: The present study was designed to evaluate the phytochemical screening, antimicrobial, and antioxidant activities from the roots and leaves of Leucas aspera.&#x0D; Methods: The phytochemical screening and Fourier transform infrared (FTIR) analysis of root and leaf extracts were studied using standard methods. The disk diffusion method was performed to analyze the antimicrobial activity of aqueous extract, methanol extract and hexane extract of root and leaf against to selected bacterial and fungal strains. Antibiotics, streptomycin and nystatin were used as standards for bacteria and fungi, respectively. The antioxidant activity of the extracts was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and scavenging of H2O2 free radicals.&#x0D; Results: Preliminary phytochemical screening of extracts exhibited the presence of carbohydrates, proteins, amino acids, steroids flavonoids, terpenoids, saponins, alkaloids, tannins, and phlobatannins. Leaf extracts exhibited effective antibacterial and antifungal activities compared with root extracts against all the tested bacteria and fungi. ME of the leaves exhibited highest antibacterial activity against Staphylococcus aureus (12.8±0.31 mm), followed by Bacillus subtilis (11.4±0.3 mm), Escherichia coli (9.8±0.21 mm), and Pseudomonas aeruginosa (7.3±0.29 mm). Leaf extracts of L. aspera showed effective scavenging activity compared with root extracts. ME of the leaves showed maximum scavenging activities of 38.39 and 36.85%, respectively, against DPPH and H2O2 free radicals with half maximal inhibitory concentration values of 136.17 and 142.42 μg/ml.&#x0D; Conclusion: Phytochemical analysis and FTIR spectrum revealed that different plant secondary metabolites particularly alkaloids, terpenoids, and flavonoids could be responsible for antimicrobial and antioxidant activities of L. aspera leaf extracts.

Anti-Inflammatory and Antimicrobial Activities of Aqueous Extracts of Wild Mushrooms from Japan

Anti-Inflammatory and Antimicrobial Activities of Aqueous Extracts of Wild Mushrooms from Japan

Antimicrobial Activity of Aqueous Extracts of Potentilla Reptans L. Rhizome and Aerial Part

Abstract Potentilla reptans is a little studied plant of the genus Potentilla, the family Rosaceae. The aim of this study is to determine antimicrobial effects of aqueous extracts of P. reptans aerial part and rhizome against standardized bacterial strains. The antimicrobial activity of aqueous extracts of P. reptans aerial part and rhizome was tested against one fungus, Candida albicans, and two standard bacterial strains, Staphylococcus aureus and Escherichia coli, using an agar diffusion method. Both examined extracts showed a significant antimicrobial activity against Escherichia coli and Staphylococcus aureus at the concentrations of 10 to 150 mg/ml. The rhizome extract showed stronger antimicrobial effect against the tested strains of bacteria than the aerial part extract. The obtained results represent preliminary results of antimicrobial activity of this plant and suggest that in future, the studies should examine antimicrobial activity against other bacterial strains and minimum inhibitory concentration.

Antimicrobial Activity of Araucaria angustifolia Seed (Pinhão) Coat Extract and its Synergism with Thermal Treatment to Inactivate Listeria monocytogenes

The objective of the present work was to evaluate the antimicrobial activity of aqueous extract from solid waste of Araucaria angustifolia seed (pinhao) at concentration of 10 kg/m3 against a broad spectrum of bacteria and fungi and its synergism with heat treatment against Listeria monocytogenes within temperature range of 55–70 °C. Results showed that pinhao coat extract inhibited the growth of Staphylococcus aureus, Bacillus cereus, L. monocytogenes, L. innocua, and Aeromonas hydrophila, but did not inhibit the fungi evaluated. Kinetic modeling showed that L. monocytogenes inactivation followed the first order model. Results showed that the inactivation rate constant increased 105% when L. monocytogenes was treated at 55 °C in the presence of pinhao coat extract; meanwhile, there was an increase of 58% and 42% at 60 °C and 70 °C, respectively, indicating clearly a synergism between heat treatment and the aqueous extract obtained from the food residue. Thus, pinhao coat extract presents antibacterial activity against important foodborne bacteria and its combination with heat processing implies in reduction of the thermal stability of L. monocytogenes, indicating that the combination of both techniques can be an interesting tool to be used in food preservation.

Phytochemical Properties and Antimicrobial Activities of Aqueous Extract of Curcuma longa (Turmeric) Rhizome Extract

Phytochemical Properties and Antimicrobial Activities of Aqueous Extract of Curcuma longa (Turmeric) Rhizome Extract

Antimicrobial activity of phenolic extracts and essential oil from Thymelaea hirsuta

In the current study, the antimicrobial activity of aqueous extract,organic solvents (petroleum ether, dichloromethane, methanol and ethanol extracts) as well as the essential oil of Thymelaea hirsuta was evaluated on various strains of dermal bacteria and fungi. Screening of phytochemicals was also carried out in order to determine the secondary metabolites available in the mixture (leaf / flower) of the plant. The activities of the T. hirsuta extracts were determined by diffusion method in agar medium for the bacteria and the direct contact procedure for the fungi for.The results obtained showed that all the extracts had an inhibitory activity on the growth of bacteria S. aureus and P. aeruginosa. The essential oil obtained by hydrodistillation showed the greatest influence on these strains. In addition, the antifungal activities of these extracts caused a short duration of the fungus activity (Microsporum audouinii, Microsporum gypseum and Trichophyton rubrum) and this effect depended on the concentrations of the extracts applied. The level of inhibition was also found to vary with procedure of the extraction used. Overall, the studied extracts have the potential to be used as antimi-crobial agents against the tested microbes.

Cistus incanus L. commercial products as a good source of polyphenols in human diet

Recently numerous manufacturers promote herbal infusions and dietary supplements based on the plant Cistus incanus because of its high content of phenolic compounds and strong antioxidant activity. Thus, the aim of this study was to assess the phenolic profile and antioxidant capacity of hydromethanolic and aqueous extracts of commercial C. incanus products. Individual phenolic acids and flavonoids were determined using HPLC, while antioxidant capacities were evaluated by use of scavenging assays of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and ferric reducing/antioxidant power (FRAP). Total phenolic, flavonoid, phenolic acid and L(+)-ascorbic acid contents were quantified using UV–vis spectrometry, whereas in vitro antimicrobial activities of aqueous extracts of C. incanus were investigated by the broth microdilution technique using 96-well plates. The place of origin was the main factor in differentiating C. incanus samples. The results revealed that aqueous extracts of C. incanus are richer in phenolic compounds and have stronger antioxidant activities than hydromethanolic extracts. Moreover, aqueous extracts revealed antibacterial activities more effective against Gram-positive bacteria, particularly S. aureus (MIC values from 0.5 to 32mg/mL) and S. epidermidis (MIC values from 0.25 to 8mg/mL) than Gram-negative bacteria. They were also weak inhibitors of C. albicans and C. glabrata growth (MIC values over 8mg/mL).

Evaluation of the Antimicrobial Activity of Tribulus terrestris, Allium sativum, Salvia officinalis, and Allium hirtifolium Boiss Against Enterococcus faecalis

Background: Enterococcus faecalis is a Gram-positive, commensal bacterium which can cause life-threatening infections in humans. E. faecalis has been frequently found in root canal-treated teeth and is resistant to many commonly used antimicrobial agents. Nowadays modern medicine recognizes herbalism as a form of alternative medicine. Tribulus terrestris, Allium sativum, Salvia officinalis and Allium hirtifolium Boiss are commonly found in Iran and used as antimicrobial agents in folklore medicine. Objectives: In this study, antimicrobial activities of aqueous extracts of some plants were examined in vitro against E. faecalis. Materials and Methods: Antibacterial activities of the extracts of T. terrestris, A. sativum, S. officinalis and A. hirtifolium Boiss were examined using disc and well diffusion methods, and the19 minimum inhibitory concentration (MIC) of aqueous extracts were determined against E. faecalis using agar and broth dilution methods. Results: The obtained results showed that the extract of A. hirtifolium Boiss inhibited the growth of E. faecalis (MIC of 10 mg/mL). Other plants had no effect on the target bacterium. Conclusion: According to the best effect of A. hirtifolium extract on E. faecalis and stability of this extract in thermal condition, we may purify this extract and use it for treatment of infections.

Antimicrobial activity of aqueous extracts from four plants on bacterial isolates from periodontitis patients.

Four aqueous extracts of different plant organs are the following: Artemisia herba-alba, Opuntia ficus-indica, Camellia sinensis and Phlomis crinita were evaluated against two bacterial strains: Porphyromonas gingivalis and Prevotella intermedia, which are implicated in periodontal diseases. By using a disc method, these plant extracts demonstrated powerful bacterial activity against these Gram-negative strains. The minimum inhibitory concentration values of the four plant extracts varied between 0.03 and 590.82mg/ml for the microbes. Another assay using commercial antibiotics and antibacterials as positive controls was also conducted. Values obtained after statistical analysis of inhibition diameters of all plant extracts demonstrated that for P. gingivalis, the aqueous extracts of A. herba-alba and O. ficus-indica were most effective, followed by those of C. sinensis and P. crinita. For P. intermedia, aqueous extracts of O. ficus-indica and C. sinensis appeared to be more efficient with significantly different (P>0.05) inhibition diameters, followed by those of O. ficus-indica and P. crinita. In summary, the statistical results reveal that these plant extracts exert stronger antibacterial activity on P. intermedia germ as compared to P. gingivalis.

Antimicrobial analysis of Triphala and comparison with its individual constituents

Triphala, a well known ayurvedic formulation is used against number of ailments since ancient times. It consists of Emblica officinalis, Terminalia chebula and Terminalia bellerica in equal proportion. Triphala as a whole and its three individual constituents show specific antimicrobial activity against certain bacteria and fungi. Antimicrobial activity of aqueous extract of triphala and its constituents was studied against P.aeruginasa, E.coli , B.subtilis, K. pneumoniae and S.aureus by cup-plate method. Triphala was found strongly bactericidal against P. aeruginosa with 1.8 cm of inhibitory zone. This was on account of T. chebula which showed 1.2 cm of inhibitory zone against the same pathogen, followed by E. coli and other two Gram positive bacteria. T. bellerica however showed maximum inhibitory activity against B.subtilis by showing 2.2 cm of inhibitory zone. It was confirmed that antimicrobial activity against Gram negative bacteria is due to T. chebula and E. officinalis while antimicrobial activity against Gram positive bacteria is on account of T. bellerica. Antifungal activity of Triphala and its constituents was studied against two pathogenic fungi viz. Aspergillus niger and Candida albicans by the same method. Triphala was found more efficient against A. niger, this was on account of T. bellerica which showed nearly 2 cm zone of inhibition. T. bellerica and Triphala showed more than 2 cm inhibitory zone against C. albicans. Inhibitory zone of Emblica officinalis was observed to be of 1.5-2 cm against both the fungi, whereas T. chebula did not show inhibitory activity against C. albicans but showed nearly 1 cm of inhibitory zone against A. niger. This confirms that the antifungal activity of Triphala is primarily due to T. bellerica and E. offiicinalis.

In vitro antimicrobial activity of aqueous extracts from Lentinula edodes isolates against Colletotrichum sublineolum and Xanthomonas axonopodis pv. Passiflorae

The aim of this study was to evaluate the antimicrobial activity of aqueous extracts from fruiting bodies of different isolates of Lentinula edodeson the pathogens Colletotrichum sublineolum, the causal agent of anthracnose in sorghum, and Xanthomonas axonopodispv. passiflorae, the causal agent of bacterial spot in passion fruit. Results showed that the aqueous extracts from isolates LE JAB-K and LE 95/01 significantly reduced C. sublineolumspore germination,while the isolate LE 96/22 was the only one to inhibit the pathogen mycelial growth. However, all L. edodesisolates showed inhibitory effect on C. sublineolumappressorium formation. Regarding X. axonopodispv. passiflorae, the aqueous extracts from all L. edodesisolates significantly reduced the in vitromultiplication of the bacterium. However, antimicrobial activity was lost when the extracts were autoclaved, demonstrating their thermolabile property. The aqueous extract from isolate LE 96/22 was also partially purified by anion exchange chromatography and fraction V exhibited high inhibitory activity on the in vitromycelial growth of C. sublineolum, while the multiplication of X. axonopodispv. passifloraewas inhibited by fractions IV, V and VII. Thus, L. edodesisolates were shown to produce compounds exhibiting antifungal and antibacterial activities against phytopathogens, which are mainly concentrated in fraction V.

Effect of clove and cinnamon extracts on experimental model of acute hematogenous pyelonephritis in albino rats: Immunopathological and antimicrobial study.

Recent studies showed prominent antimicrobial activity of some plant extracts on some pathogenic microorganisms so we evaluated antimicrobial activity of aqueous extracts of clove and cinnamon using the agar well diffusion method. An in vivo study was carried out on 40 adult healthy male albino rats divided into four groups: Group 1: negative control group (received intragastric saline solution daily); Group 2: injected with mixed bacterial suspension of S. aureus and E.coli as a model of pyelonephritis then received intragastric saline solution daily; Group 3: injected with the same dose of mixed bacterial suspension then received intragastric clove extract 500 mg/kg/day; and Group (4): injected with mixed bacterial suspension then received intragastric cinnamon 500 mg/kg/day. Five rats from each group were sacrificed after 1 and 4 weeks. Serum and blood samples were collected for lysozymes activity and nitric oxide production, lymphocyte transformation test, as well as counting of both total and differential leukocytes and erythrocytes. Kidney samples were tested histopathologically. Both in vivo and in vitro results confirmed the efficacy of clove extract as natural antimicrobials and suggested the possibility of its use in treatment of such bacterial infections.

Etude De L'activité Biologique Des Extraits Aqueux D’euphorbia Guyoniana "Euphorbiaceae" Récoltée Dans Oued Sebseb "Sahara Algérien"

The study focuses on the toxicity of leaf extracts of Euphorbia guyoniana Boiss. & Reut (Euphorbiaceae), harvested in Oued sebseb, northern Sahara eastern Algeria on some bacterial and fungal strains. The crude extract of Euphorbia guyoniana has low antibacterial activity for Staphylococcus aureus with an area of 8.5 mm, and Escherichia coli is 7.67 mm; Protus mirabilis for 7mm; and Micrococci lutus and Bacillus subtilis by 6mm inhibition zone, and therefore also for the other dilutions were labeled low less antimicrobial activity of 8mm, except for Staphylococcus aureus resulting in a 9.33 mm zone of inhibition with the 10 -6 and 10 -4 with 8.33 dilution. The study of the antimicrobial activity of aqueous extracts of E. guyoniana reveals weak antimicrobial activities. Keywords : Euphorbia guyoniana , aqueous extract, antimicrobial activity, Sahara.

Comparative testing of antimicrobial activity of aqueous extracts of Aloe vera and Lycium barbarium

Plants have a very important role in natural medicine because of their composition rich in vitamins, minerals, antimicrobial and immunomodulatory compounds. Since antibioresistance to some antibiotics used in current therapy in human medicine and veterinary medicine is nowadays a major problem, researches have searched for alternative methods of replacement or combination of antibiotics with different plant extracts with antimicrobial and/or immunomodulatory effect. This experiment was designed to evaluate the comparative antimicrobial effect of aqueous extracts of aloe (Aloe vera) and goji berries (Lycium barbarum) on some species of bacteria and fungi. We used for this experiment five kinds of aqueous extracts of aloe vera (two extracted from the for six months old plant, two from a 4 years old plants and a standard commercially available aqueous extract). Five types of aqueous extracts of goji fruit (1/1 goji soak, total aqueous extract, fruit centrifuged supernatant, fruits supernatant filtered through 0.2μm Millipore and watery sediment from plant mortar) were also tested. Four kinds of microorganisms including Gram-positive bacteria (Staphylococcus aureus ATCC 6538P), Gram-negative bacteria (Escherichia coli ATCC 10536, Pseudomonas aeruginosa ATCC 27853) and fungi (Candida albicans ATCC 10231) were used for determining the sensitivity. Testing was done by disc diffusion method with some changes according to the tested compounds. The interpretation of disk diffusion test revealed that Aloe vera extracts had inhibitory effect only on the strains of Staphylococcus aureus ATCC 6538P, the effect being stronger for total extract (100%) as well as for standardized extract. The growth of Escherichia coli ATCC 10536 strain, was increased instead of being inhibited. On Candida albicans ATCC 10231 strain, only standardized extract had a good inhibitory effect. Regarding the antimicrobial effect of aqueous extracts of goji fruit we found a weak inhibitory effect, however, observing a strong inhibitory effect on E. coli strain. This study demonstrated that aqueous extracts of aloe and goji have antimicrobial effect, which depends on the concentration of the extract and the type of microorganism tested. The results can represent a prospect into the use of these extracts as substitutes for antibiotics or along with antibiotics and may have practical applications in medicine, cosmetics and food industry.

Antimicrobial activity of aqueous extracts of sea cucumber (Isostichopus badionotus) from the coast of Yucatan, Mexico

The antibacterial activity of aqueous extracts from different tissues of Isostichopus badionotus was evaluated in this study. The antibacterial activity was detected in aqueous extracts of muscle and respiratory tract. A high antibacterial activity was found in the Membrane Protein fraction (MP) muscle on Staphylococcus aureus, Vibrio cholerae, Escherichia coli and Pseudomonas aeruginosa. The minimum inhibitory concentration (MIC) of MP against S. aureus was 37.4 and 8.4 μg/ml protein for V. cholerae. It also showed resistance to treatment with proteinase K and heat, indicating that the active compound of this fraction is from non-protein origin. The results of this study suggest that I. badionotus is a potential source for discovering new antibiotics.

Phytochemical, Antioxidant and in vitro Antibacterial Activity of Aqueous and Ethanolic Fruit Extracts of Kigelia Africana

Phytochemicals presents in plants probably explain the various uses of plants for traditional medicine. In this study Kigelia Africana fruit was selected for assessing the level of various Phytochemicals, enzymatic and non- enzymatic antioxidants and antimicrobial activity. Fruits of the plant taken, dried, grind to powder and then aqueous and ethanolic extracts were prepared. Antimicrobial activity of these extracts was then studied using agar well plate method. Results of the study showed that aqueous extract of Kigelia Africana have significant amount of phytochemicals and antioxidant enzymes so useful to prevent chronic diseases related to oxidative stress in human body. Antimicrobial activity of aqueous extract was more than the ethanolic extract.