Antimicrobial Activity Of Extracts Research Articles

Antimicrobial activities of extracts from Urtica urens

The antibacterial and antifungal activities of various extracts from Urtica urens were evaluated against selected microorganisms using agar hole-plate diffusion method. A total of ten extracts namely U. urens hexane leaf extract (HLE), chloroform leaf extract (CLE), ethyl acetate leaf extract (ELE), methanolic leaf extract (MLE), hexane stem-bark extract (HSB), chloroform stem-bark extract (CSB), ethyl acetate stem-bark extract (ESB), methanolic stem-bark extract (MSB), chloroform root extract (CRT) and methanolic root extract (MRT) were prepared. These extracts were evaluated against two Gram-positive bacteria viz. Listeria monocytogenes and Staphylococcus aureus, four Gram-negative bacteria viz. Serratia marcescens, Pseudomonas aeruginosa, Escherichia coli (wild strain) and Escherichia coli (O157:H7) and two fungal isolates viz. Candida albicans and Penicillium digitatum. The inhibition zones of these extracts were found to be in the range of 9.0±0.0 to 40.5±0.7 mm against bacterial isolates and 16.0±4.2 to 17.5±4.9 mm against C. albicans. However, all these extracts exhibited no visible zone of inhibition against P. digitatum. Additionally, the minimum inhibitory concentrations (MICs) of these extracts were also determined and were found to be in the range of <31.25 to >1000 µg/mL against both bacterial and fungal isolates. From this study, we concluded that ELS, MLE, CRT and MRT showed promising antimicrobial activities.

ANTIMICROBIAL AND ANTIOXIDANT EFFECT OF NATURAL EXTRACTS FROM LEAVES, ROOT, STEM AND FLOWERS OF BACCHARIS LATIFOLIA FROM ECUADOR

Objective: The increase in chronic and degenerative diseases and the use of synthetic antioxidants such as (butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT)) are being restricted because they can be considered carcinogenic. Therefore, there is a growing interest in the search for natural antioxidants, especially from plants, due to their content in different bioactive compounds, such as antioxidants and antimicrobials. To evaluate the antibacterial and antioxidant activity of Baccharislatifolia extracts.
 Methods: For the determination of the antimicrobial activity of extracts of leaves, root, stem and flowers of Baccharislatifolia (Bl), the disk plate diffusion method was used, the strains of Listeria, Salmonella and E. coli were studied; antibiotics Penicillin G and Ciprofloxacin were the controls. For the antioxidant activity, a solution of H2O2 (Abs at 230 nm) was prepared in Potassium Phosphate Monobasic-Sodium Hydroxide buffer.
 Results: The antimicrobial activity against Listeria and Salmonella, showed that the extracts of leaves and flowers were more effective with inhibition zones>15 mm and>20 mm respectively. In front of E. coli, the extracts of flowers and stem were the best with zones>7.0 mm. Antibiotics studied inhibited the development of Listeria and Salmonella. However, E. coli isolates were resistant. In the antioxidant activity, the flower extract of Bl in 60 mg/ml presents a higher effect with 47.25%.
 Conclusion: Bl extracts from leaves and flowers were more efficient both in their antimicrobial and antioxidant capacity.

The Biofilm Inhibitory Potential of Compound Produced from Chlamydomonas reinhardtii Against Pathogenic Microorganisms

Microalgae present much usefulness for antimicrobial research because of its enormous biodiversity and rapid growth rate. From this study results it is reaveled that Chlamydomonas reinhardtii were isolated from a pond of water in the province of Diwaniyah. The culture supernatants were obtained when extracted with methanol solvent. Antimicrobial activity of extracts was tested for pathogens, and the best inhibition zone obtained was against Candida albicans (32mm), S.aureus (15mm), and to E.coli (9mm). While it showed no effect against both S.epidermidis and Klebsiella spp. Biofilm was formed by all tested isolates with differences in its strength formation. The C. reinhardtii Algal extract showed higher reduction of the existing Staphylococcus aureus biofilm and (10.9 %) was the remaining biofilm, while 55.21% and 54.98% were to Serratia spp. and Escherichia coli respectively, and it’s the lowest reduction. Klebsiella spp., Candida albicans, Acinetobacter spp., Staphylococcus epidermides, and Aspergillus sp. showed remaining biofilm as (16.7, 18.3, 19.6, 43.6, and 44.1) % respectively. The composition of the volatile compounds of the C. reinhardtii extract was determined by GC/MS. Different groups of compounds were identified such as hydrocarbons, phenols, alcohols and esters, and two bioactive compounds;1-Heptacosanol and Octadecyl chloride which is used in medical and pharmaceutical fields.These results provide an indication of the existence of hopeful antibiofilm compounds in the algal species under study. Further chemical studies are required to illuminate these compounds, structures and activity.

Study and evaluation of antimicrobial activity and antioxidant capacity of dry extract and fractions of leaves of Raphanus sativus var. oleiferus Metzg.

The radish (Raphanus sativus L.) is a vegetable of the Brassicaceae family cultivated worldwide and has several medicinal properties. Its biological activities are related to various secondary metabolites present in the species, especially phenolics. Thus, the objectives of this study were the chemical analysis and evaluation of the antioxidant and antimicrobial activities of the dry extract and fractions of the fodder turnip leaves (R. sativus var. oleiferus Metzg.). Samples were analyzed by mass spectrometry and the antioxidant activity was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method and the reducing power method. Antimicrobial activity was determined by the agar diffusion and microdilution methods. The total phenols were concentrated in the butanol fraction (121.27 mg GAE/g) and the flavonoids were concentrated in the ethyl acetate fraction (98.02 mg EQ/g). The ethyl acetate fraction showed the best antioxidants results, with 83.45% of free radical scavenging and 11.34% of ferric ions reduction. The analysis of antimicrobial activity showed that the dry extract had the highest average zone of inhibition against Bacillus subtilis (18.67 mm). Smaller values of the minimum inhibitory concentration for Micrococcus luteus were, and the ethyl acetate fraction showed a lower minimum inhibitory concentration (0.1 mg/ml) for that microorganism. There was a strong correlation between the antioxidant activity and the content of phenols and flavonoids. The results showed the potential antioxidant and antimicrobial activities of this extract with the ethyl acetate fraction being most promising for further studies.

Antimicrobial Activity of Extracts of Medicinal Plants Hipericum Perforatum, Matricaria Chamomilla, Geranium Sangguineum and Nepeta Cataria and their Application in the Treatment of Certain Infectious Diseases in Macedonia

For our research survey was conducted on the entire territory of the Republic of Macedonia...

In Vitro Antibacterial and Antifungal Studies of Pulicaria undulate and Echinacea purpurea Extracts in Combination with Nanowires (Ni:FeO(OH)) and Nanoparticles (NiS)

Background: Due to the presence of many antimicrobial-resistant pathogens, researchers are trying to substitute antibacterial drugs with other nanostructures and medicinal plants. Objectives: This study aimed to assess the antibacterial/antifungal and DNA cleavage characteristics of Pulicaria undulate and Echinacea purpurea extracts with/without Ni:FeO(OH) nanowires and NiS nanoparticles. Methods: The antimicrobial activities of extracts in combination with nanostructures were assessed using MIC, MBC, and disc diffusion methods against Aspergillus oryzae, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis and DNA electrophoresis methods against E. coli. Also, the chemical constituents of extracts and the structures of nanowires/nanoparticles were analyzed by GC-MS and X-ray/SEM, respectively. Results: The main constituents of Pulicaria undulate and Echinacea purpurea extracts were Nonadecane (13.8%) and phytol (17.7%), respectively, in GC analysis. In the disc diffusion method, Ni:FeO (OH)-NW had more effects on Gram-positive bacteria and NiS-NP showed antibacterial effects on Gram-negative bacteria. Also, the combination of Echinacea purpurea and NiFeO(OH) had the most antibacterial effects on Pseudomonas aeruginosa and Staphylococcus aureus (19 and 20 mm, respectively). The lowest MIC effects were seen for Pulicaria undulate and NiS (0.195 mg/mL) against E. coli. Also, the lowest MBC effects were seen for Echinacea purpurea and Ni-doped FeO(OH) against Staphylococcus aureus (0.195 mg/mL). The combination of NiS-NP and Pulicaria undulate had the most DNA cleavage effect. Conclusions: The combination of Pulicaria undulate and Echinacea purpurea extracts with nanostructures was effective to eliminate the bacteria. Therefore, the synergistic effect of the combination of plant extracts and nanoparticles brings about new options for the treatment of microbial diseases.

Biological activities and phytochemical screening of leaf extracts from Zanthoxylum caribaeum L. (Rutaceae)

The Brazilian flora is known for its vast biodiversity; however, many species have been still little studied regarding to their chemical composition and biological potential. Thus, this study aimed to determine the antimicrobial, antioxidant and acaricidal activity of the extracts of leaves of Zanthoxylum caribaeum L. In addition, phytochemical screening of these extracts was carried out to determine the main classes of secondary metabolites present in Z. caribaeum. Using the Z. caribaeum leaves, the aqueous extract and extracts were obtained in organic solvents (ethanol, methanol, hexane, acetone, dichloromethane and ethyl acetate). The antimicrobial activity of extracts was determined by broth microdilution method, and to detect antioxidant activity the method of capturing the free radical 2,2-diphenyl-1-picryl hydrazyl (DPPH) was used. The acaricidal activity of the extracts was tested on Dermanyssus gallinae (De Geer) (Acari: Dermanissidae). Ethanolic and methanolic extracts presented antimicrobial activity for most of the bacterial strains tested, as well as for yeast Candida albicans. The ethanolic extract presented high free radical sequestration potential (71.2%) and antioxidant capacity (the lowest IC50 value - 24.39 μg mL-1). The extracts obtained with methanol and acetone were the most promising. In general, phytochemical screening indicated the presence of steroids, flavanones, flavones, flavonols, saponins, tannins, triterpenoids and xanthones.

Antimicrobial Activities of Extract from Seeds of Baccaurea Ramiflora

Antimicrobial Activities of Extract from Seeds of Baccaurea Ramiflora

Phytochemical Analysis, Multi-Element Composition and Biological Activities of Extracts and Lupenone from Albizia inundata (Mart.) Barneby & J.W.Grimes

In this study, antimicrobial activity of extracts and lupenone from A. inundata (Fabaceae, Mimosoideae), were tested. In addition, the multi-element composition of the leaves, bark and stems (heartwood) of A. inundata was evaluated using inductively coupled plasma optical emission spectrometry (ICP OES). Lupenone was isolated in the petroleum ether extract of leaves, for the first time. Biological assays were conducted to evaluate the antimicrobial (antibacterial, antifungal and antiparasitic) of extracts, their fractions and lupenone. The results showed antimicrobial and antileishmanial activity of these compounds, which may be useful for obtaining a chemical composition and biological activity database on Albizia species. For multi-element composition, we found the mean concentrations (minimum-maximum) of Al, Ca, Cr, Cu, Fe, K, Mg, Mn, Ni, P, V and Zn in the samples ranged between 0.06 and 265.41 µg g-1. Concentration ranges of Cu, Fe, Mn and Zn are large, which makes these samples as additional sources of these macronutrients.

Anti-Acinetobacter baumannii activity of Rumex crispus L. and Rumex sanguineus L. extracts

Objective: To examine the effect of Rumex crispus (R. crispus) and Rumex sanguineus (R. sanguineus) plant extracts against isolates of Acinetobacter baumannii (A. baumannii) from wounds, including multidrug-resistant strains. Methods: Six prepared Rumex extracts were subjected to liquid chromatography-tandem mass spectrometry. Antimicrobial activity of extracts and pure compounds (catechin, quercetin, isoquercitrin, emodin, and gallic acid) was examined by a microtiter plate method, while for determination of compound binary combinations activity a checkerboard method was applied. Active fractions of extracts were detected by agar-overlay high-performance thin- layer chromatography-bioautography assay followed by liquid chromatography - diode array detection - mass spectrometry analysis. Results: A total of 28 compounds were detected in two extracts of R. crispus and 26 compounds in four different R. sanguineus extracts, with catechin as a dominant component. Anti-A. baumannii activity was confirmed for all six R. sanguineus and R. crispus extracts at the concentration range from 1 to 4 mg/mL. Neither examined single compounds nor their binary combinations exhibited an anti-A. baumannii activity (MIC>256 μg/mL). The bioautography showed that fractions with the most prominent anti-A. baumannii activity tended to contain more polar compounds, predominantly flavonol (quercetin and kaempherol) glycosides; but also fractions containing flavanone (eriodictyol) glycosides and anthraquinone (emodin) glycosides; and less polar eriodictyol aglycone. Conclusions: The results justify and elucidate the traditional application of R. sanguineus and R. crispus extracts for wound healing, indicating the necessity for their further examination in combat against multidrug-resistant A. baumannii isolates from wounds.

Determination of Phenolic Content, Ascorbic Acid, Antioxidant Activity and Antimicrobial Activity of Selected Fruit Waste

The aim of this study was to determine the total phenolic content (TPC), antioxidant activity, ascorbic acid content and antimicrobial activity of extracts obtained from cocoa pod husk, banana peel and pineapple peel. Banana peel had significantly highest total phenolic content (154.50 mg GAE/g) followed by pineapple peel (140.37 mg GAE/g) and cocoa pod husk (114.08 mg GAE/g). Antioxidant activity of these samples measured using DPPH assays. Banana peel showed significantly higher DPPH scavenging activity (95.74%) compared to pineapple peel (84.96%) and cocoa pod husk (68.33%). Pineapple peel resulted in significantly higher (44.19 ppm) ascorbic acid as measured using High performance liquid chromatography (HPLC) method compared to banana peel (28.56 ppm). Cocoa pod husk, banana peel and pineapple peel were observed for antimicrobial activity against Escherichia coli, Staphylococcus aureus and penicillium. Samples extract at different concentrations in E. coli, S.aureus and penicillium-seeded Mueller-Hinton agar medium, resulted zone of inhibition after 24 h incubation in 37°C for bacteria and 72 h incubation in 28ºC. Banana peel at 20 and 25mg/ml against S.aureus resulted in zone of inhibition 9.67, 11.67 mm and cocoa pod husk with 8.00, 9.67 mm respectively. Cocoa pod husk at 15, 20 and 25mg/ml against E.coli resulted in zone of inhibition 7.33, 9.33 and 10.33 mm and banana peel with 6.67, 7.33 and 7.67 mm respectively. Pineapple peel does not showed any inhibition zone against tested bacteria and fungi.

Evaluation of Antimicrobial Activity and Synergistic Effect of Spices against Few Selected Pathogens

Objectives: The main objective of this study was to evaluate antimicrobial activity of ethanolic extract of spices along with determination of its synergistic effect against few selected pathogens.
 Methods: In this study, ethanolic extract of 5 different spices; Zingiber officinale (Ginger), Allium sativum (Garlic), Curcuma longa (Turmeric), Capsicum annum (Chili) and Allium cepa (Onion) were obtained by using Soxhlet apparatus. The ethanolic extract was concentrated by evaporation and different concentrations of extract were prepared in Dimethy Sulphoxide (DMSO) solvent. Test organisms included mainly pathogens i.e. Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae. The antimicrobial activities of the extracts were determined by well diffusion technique both individually and in combination. On the other hand, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) was determined by serial dilution technique. The result were interpreted on the basis of the fact that the growth occurs in positive control and other tubes with inadequate amount of extract whereas the lowest concentration of agent that inhibits growth of organism, detected by lack of visible turbidity by inhibition of 99% is designed as the MIC. The MBC is identified by determining the lowest concentration of extract solution that reduces the viability of the initial bacterial inoculum by a predetermined reduction such as ≥99.9%. Likewise, for determination of Fractional Inhibitory Concentration Index (FICI), two extracts were combined along with standardized inoculum of bacterial strain. Tubes without visible turbidity were streaked on agar plate and observed for 99.9% killing. 
 Results: All the tested extract of spices were found effective against S. aureus and K. pneumoniae only. The highest zone of inhibition (ZOI) was found in chili extract (ZOI=26 mm) against S. aureus whereas lowest zone of inhibition was found in garlic extract against K. pneumoniae (ZOI=12mm). Similarly, highest ZOI was produced by combined extract of both Turmeric and Ginger (ZOI= 26 mm). Turmeric extract was found to be effective against S. aureus (MIC value = 62.5 mg /ml and MBC value = 31.25 mg/ml) and K. pneumoniae (MIC value 125 mg/ml and MBC value = 62.5 mg/ml). The Fractional Inhibitory Concentration (FIC) values of combined extract suggested synergistic and additive effect (0.5<FIC<1). Chili and ginger were effective with FIC value of 0.25.
 Conclusion: To recapitulate, the extract of spices can be used to prevent the pathogenic organism.

Plant therapy in the Peruvian Amazon (Loreto) in case of infectious diseases and its antimicrobial evaluation.

The plant species reported here are used in contemporary phytotherapies by native and neo-urban societies from the Iquitenian surroundings (district of Loreto, Peruvian Amazon) for ailments related to microbial infections. Inhabitants of various ethnic origins were interviewed and 81 selected extracts were evaluated for their antimicrobial properties against a panel of 36 sensitive and multi-resistant bacteria or yeast. Medicinal plant researches in the Peruvian Amazon are now significant, but none of them has focused on an exhaustive listing of identified species tested on so many microbes with standardized experiments (to obtain MIC value). The aim of the study was to inventory the plants used against infections in the Loreto, an Amazonian region of Peru. It led to the new identification of secondary metabolites in two plant species. Ethnographic survey was carried out using "participant-observation" methodology and focus on bioprospecting of antimicrobial remedies. Selected plant extracts and antimicrobial drugs were tested in vitro with agar dilution method on 35 bacteria strains and 1 yeast to evaluate their Minimal Inhibitory Concentration (MIC). Microdilution methods using 96-well microtiter plates were used for the determination of MIC from isolated compounds, and cytotoxicity in HepG2 cells from some selected extracts were also evaluated. Activity-guided isolation and identification of compounds were performed by various chromatographic methods and structural elucidations were established using HRMS and NMR spectroscopy. This study outlined antimicrobial activities of 59 plant species from 33 families (72 single plant extracts and 2 fermented preparations), 7 mixtures, and one insect nest extract against 36 microorganisms. Of the 59 species analysed, 12 plants showed relevant antibacterial activity with MIC ≤0.15mg/mL for one or several of the 36 micro-organisms (Aspidosperma excelsum, Brosimum acutifolium, Copaifera paupera, Erythrina amazonica, Hura crepitans, Myrciaria dubia, Ocotea aciphylla, Persea americana, Spondias mombin, Swartzia polyphylla, Virola pavonis, Vismia macrophylla). Examination by bioautography of E. amazonica, M. dubia and O. aciphylla extracts allowed the phytochemical characterization of antimicrobial fractions and compounds. This study suggested an a posteriori correlation of the plant extract antimicrobial activity with the chemosensory cues of the drugs and attested that those chemosensory cues may be correlated with the presence of antimicrobial compounds (alkaloids, tannins, saponosids, essential oil, oleoresin …). It also led to the first isolation and identification of three secondary metabolites from E. amazonica and M. dubia.

Chemical Composition and Antimicrobial Activity of Bark and Leaf Extracts of Cupressus sempervirens and Juniperus phoenicea Grown in Al- Jabel Al-Akhdar Region, Libya

Background:Plant extracts are important products in the world and have been widely used for isolation of important biologically active products. Because of their significant environmental impact, extensive research has been explored to determine the antimicrobial activity of plant extracts.Methods:Acetone extracts of the bark and leaf of Cupressus sempervirens and Juniperus phoenicea, collected from three different altitudes (125, 391, and 851 m high of sea level) at Al- Jabel Al-Akhdar area, Libya were obtained and analyzed by GC/MS. The antimicrobial activity of the extracts was further evaluated against plant bacteria Rhizobium radiobacter, Erwinia carotovora, Rhodococcus fascians and Ralstonia solanacearum and fungus Botrytis cinerea.Results:The impact of the altitude from the sea level on the quantity and chemical constituents of the extracts was investigated. The yield was largely dependent on tree species and the highest yield (6.50%) was obtained with C. sempervirens L bark of altitude III (851 m of the sea level), while the lowest (1.17%) was obtained with the leaf extract of C. sempervirens L from altitude I (125 m). The chemical composition analyzed by GC/MS confirmed that the leaf extracts of C. sempervirens and J. phoenicea contained a complex mixture of monoterpene hydrocarbons, sesquiterpenes, diterpenes, diterpenoids, terpenophenolic, steroids and phthalates. However, the bark extracts of both trees contained a mixture of sesquiterpenes, diterpenes, diterpenoids, terpenophenolics, phthalates, retinol and steroids. These constituents revealed some variability among the extracts displaying the highest interesting chemotype of totarol (terpenophenolic) in all extracts (14.63-78.19% of the total extract). The extracts displayed a noteworthy antifungal potency with varying degrees of inhibition of growth with EC50 values ranged from 78.50 to 206.90 mg/L. The extracts obtained from the leaves of C. sempervirens showed that the highest inhibitory activity was obtained with the extract of altitude II (391 m) with MIC 565, 510, 380 and 710 mg/L against E. carotovora, R. fascians, and R. radiobacter and R. solanacearum, respectively.Conclusion:Based on antimicrobial activity, raw plant extracts can be a cost-effective way to protect crops from microbial pathogens. Because plant extracts contain several antimicrobial compounds, the development of resistant pathogens can be delayed.

An investigation on phytochemical, antioxidant and antibacterial properties of extract from Eryngium billardieri F. Delaroche

It is of great interest to find new antimicrobial compounds from natural origins for new contagious diseases. For the first time, total phenolic and flavonoid contents as well as antioxidant and antimicrobial activities of ethanolic extract from aerial parts of Eryngium billardieri were evaluated in the present work. Total phenolics of the extracts ranged from 10.71 to 33.38 mg GAE/g dry extract, and the total flavonoids varied from 15.04 to 27.13 mg QE/g dry extract. Antioxidant activity of the extract was determined using the 1,1-diphenyl-2-picrylhydrazyl DPPH procedure, and found ranged between 17.25 and 51.63%. The extract prevented effectively the growth of both Gram-positive and Gram-negative bacteria. Antifungal activity of extract was measured as percentage of mycelium growth inhibition and found to be in the range of 16.7‒61.7%. The obtained results indicated that all the studied properties increased with increasing concentration of the extract. Antioxidant and antimicrobial activities of the extract were positively associated with the total phenolics and flavonoids.

Supercritical Carbon Dioxide Antisolvent Fractionation for the Sustainable Concentration of Lavandula luisieri (Rozeira) Riv.- Mart Antimicrobial and Antioxidant Compounds and Comparison with Its Conventional Extracts.

Lavandula stoechas subsp. luisieri is a Spanish subspecies from the Lamiaceae family. Its essential oil has been traditionally used for several medical applications though little is known about other extracts. Similar to many other studies aiming to obtain traditional plant extracts to be used in different applications, this work evaluated the antioxidant and antimicrobial activities of Lavandula luisieri extracts and the correlation with their composition. Traditional hydrodistillation and ethanolic maceration were used to obtain the essential oil and the maceration extract, respectively. A green and sustainable methodology was applied to the maceration extract that was under a Supercritical Antisolvent Fractionation process to obtain a fine solid enriched in rosmarinic acid and the terpenes oleanolic and ursolic acids. Antimicrobial activities of all extracts and pure identified compounds (rosmarinic and ursolic acids) were evaluated against five bacterial strains; Listeria monocytogenes, Enterococcus faecium, Staphylococcus aureus, Salmonella Typhimurium and Escherichia coli and were compared with the pure compounds identified, rosmarinic and ursolic acids. All strains were sensitive against L. luisieri essential oil. The solid product obtained from the supercritical process was concentrated in the identified actives compared to the maceration extract, which resulted in higher antimicrobial and DPPH scavenging activities. The supercritical sustainable process provided L. luisieri compounds, with retention of their antimicrobial and antioxidant activities, in a powder exemptof organic solvents with potential application in the clinical, food or cosmetic fields.

Phytochemical Study and Biological Activities of Two Medicinal Plants used in Burkina Faso: Lannea velutina A. Rich (Anacardiaceae) and Ximenia americana L. (Olacaceae)

Background: Bacterial infections are at the origin of a number of serious pathologies, including meningitis, bronchopneumopathies, typhoid fever and especially diarrhea, which are still a real public health problem for the child population in developing countries. In most of these countries, people use medicinal plants for primary health care. The objective of this study was to determine the content of phenolic compounds, the antioxidant and antimicrobial activity of extracts from two plants used in traditional medicine in Burkina Faso, Lannea velutina and Ximenia americana.
 Place and Duration of Study: Laboratory of Biochemistry and Applied Chemistry (LABIOCA).
 Methods: The total phenolics and flavonoid content of the ethanolic extract extracts were determined by spectrometric assay. The DPPH and FRAP method were used to measure the antioxidant capacity of the extracts. The antibacterial potential was determined on five bacterial strains.
 Results: The ethanolic extracts of Lannea velutina showed the best polyphenol content with 969.67±8.23 ​​mgGAE/g extract against 753.145917±66.31 mgGAE/g extract for Ximenia americana. On the DPPH radical Ximenia americana gave the best activity with a percentage inhibition of 62.32±0.17% compared to Lannea velutina. This species also gave the best reducing activity with a reducing capacity of 3.45±0.97 mmol EAA/10 g of extract. Shigella dysenteria and Staphylococcus aureus were susceptible to Lannea velutina and Ximenia americana with inhibition diameters greater than 8 mm.
 Conclusion: These results showed that the extract has good antioxidant potential as well as antimicrobial activity. These extracts could be used to prevent damage from oxidative stress and infections.

BIOLOGICAL ACTIVITY OF EXTRACTS AND ESSENTIAL OILS OF TWO ERYNGIUM (APIACEAE) SPECIES FROM THE BALKAN PENINSULA

The present study describes antioxidant and antimicrobial activity of water, methanol, acetone and ethyl acetate extracts from Eryngium maritimum L. from Greece and Eryngium serbicum Pancic, growing wild in Serbia. Also, antimicrobial activity of essential oils from aerial parts was analysed. Spectrophotometric methods were used for measuring of total phenols, total flavonoids, as well as for antioxidant potential, using DPPH and ABTS methods. The total phenolic content in the extracts was determined using Folin-Ciocalteu reagent and their amounts ranged between 7.47 and 121.35 mg GAE/g. The concentrations of flavonoids in the extracts varied from 8.98 to 48.68 mg QU/g. Antioxidant activity ranged from 1.247 to 31.19 IC50 (mg/ml) and from 0.109 to 3.36 mg AA/g when tested with the DPPH and ABTS reagents, respectively. The antimicrobial activity of the extracts and essential oils was investigated using a micro well-dilution assay against the most common human gastrointestinal pathogenic bacterial strains. The most resistant bacterium was Srteptococcus pyogenes, while Staphylococcus aureus showed high sensitivity in presence of all tested extracts except on water extract of E. maritimum. Essential oil of E. serbicum showed better antimicrobial activity than E. maritimum oil. This finding suggests that investigated Eryngium species may be considered as a natural source of antioxidant and antimicrobial agents.

Investigation of Genotoxic, Antimicrobial and Antioxidant Activities of Leaf and Flower Extracts of Cynara syriaca Boiss

The mutagenicity and antimutagenicity of leaves and flower extract of Cynara syriaca Boiss were studied with Ames assay in Salmonella typhimurium TA98 and TA100 strains. While leaves extract did not show any mutagenic effects against all the tester strains with or without metabolic activation, the flower extract showed mutagenic effect against TA98 strain without metabolic activation. On the other hand, it has been observed that the extracts have antimutagenic activity against mutations induced by sodium azide and daunomycin. The antimicrobial activity of extracts was determined by disc diffusion and MIC value. Both of the extracts possess weak antimicrobial activity. Cupric reducing antioxidant capacity (CUPRAC), DPPH free radical scavenging activity, and ABTS radical cation decolorization methods were carried out to determine the antioxidant activity. Among the tested antioxidant methods, the highest antioxidant capacity was determined in ABTS radical cation decolorization assay in which both of the extracts exhibited the best effect. Flower extract exhibited higher activity also in DPPH free radical scavenging.

Total phenolic content, antioxidant and antimicrobial activities of extracts from Pistacia lentiscus leaves

The purpose of the current study was to investigate total phenolic (TPC), total flavonoids (TF) and flavonols (FV) contents, as well as antioxidant and antimicrobial activities of different extracts of Pistacia lentiscus leaves. TP compounds were quantified by Folin-Ciocalteu, while antioxidant properties were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), radical scavenging assay (RSA), Ferric reducing activity power (FRAP) and β-carotene bleaching (βCB) assay. The antimicrobial activity was assessed against Gram-positive bacteria (Micrococcus luteus, Bacillus subtilis and Listeria innocua), Gram-negative bacteriaum (Escherichia coli) and fungi (Candida pelliculosa and Fusarium oxysporum albidinis). Overall, the ethanol fraction (EEPL) exhibited the highest TPC (70.4 ± 7.07 mg GAE g-1 powder), TF (32.06 ± 1.68 mg QE g-1 powder), FV (14.36 ± 1.68 mg QE g-1 powder) and RSA (IC50 = 5.34 ± 0.2 µg mL-1). Whereas, methanol extract (EMPL) displayed the highest FRAP (1.20 ± 0.02) and dichloromethane extract (EDPL) showed a high βCB (90.32 ± 2.98%). Furthermore, the antioxidant activities of extracts exhibited strong positive correlation with TP, TF and flavonols. The extracts obtained showed good inhibitory effect against most of the bacterial and fungal strains tested, suggesting their possible use as antimicrobial agents in medical or agro-industry sectors.