Insecticidal, antimicrobial and antioxidant activities of bulb extracts of Allium sativum

ObjectiveTo evaluate the insecticidal, antimicrobial and antioxidant activities of bulb extracts of Allium sativum (A. sativum).MethodsDried bulbs of A. sativum were extracted with different solvents and evaluated for insecticidal, antimicrobial and antioxidant activities.MethodsAqueous and methanol extracts showed highest insecticidal activity (mortality rate of 81% and 64% respectively) against the larvae of Spodoptera litura (S. litura) at a concentration of 1 000 ppm. With regard to antimicrobial activity, aqueous extract exhibited antibacterial activity against gram positive (Bacillus subtilis, Staphylococcus aureu,) and gram negative (Escherichia coli and Klebsiella pneumonia) strains and antifungal activity against Candida albicans. While methanol extract showed antimicrobial activity against all the tested micro organisms except two (Staphylococcus aureus and Candida albicans), the extracts of hexane, chloroform and ethyl acetate did not show any anti microbial activity. Minimum inhibitory concentration of aqueous and methanol extracts against tested bacterial and fungal strains was 100–150 μg/mL. Antioxidant activity of the bulb extracts was evaluated in terms of inhibition of free radicals by 2, 2′-diphenly-1-picrylhydrazyl. Aqueous and methanol extracts exhibited strong antioxidant activity (80%–90% of the standard).ConclusionsAntioxidant and antimicrobial activity of A. sativum against the tested organisms therefore, provides scientific basis for its utilization in traditional and folk medicine. Also, our results demonstrated the insecticidal efficacy of A. sativum against S. litura, a polyphagous insect.     

Antibacterial potential of sponge endosymbiont marine Enterobacter sp at Kavaratti Island, Lakshadweep archipelago

ObjectiveTo isolate antibacterial potential of sponge endosymbiotic bacteria from marine sponges at Lakshadweep archipelago. Also to identify the potent bacteria by 16s rDNA sequencing and determine the antibacterial activity against clinical pathogens by MIC.MethodsSponge samples was collected from sub-tidal habitats at Kavaratti Island and identified. The endosymbiotic bacteria were isolated and selected potential bacteria which show antibacterial activity in preliminary screening against clinical pathogens Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Salmonella typhi (S. typhi), Klebsiella pneumoniea (K. pneumoniea) and Streptococcus sp. by disc diffusion assay. The crude extracts of potential bacteria LB3 was tested against clinical pathogens by MIC. The LB3 strain was identified by 16s rDNA sequencing, 1 111 bp was submitted in NCBI (HQ589912) and constructed phylogenetic tree.ResultsSponge sample was identified as Dysidea granulosa (D. granulosa) and potential bacteria LB3 identified as Enterobacter sp TTAG. Preliminary screening of sponge isolates against clinical pathogens, LB3 strain was selected as potential producer of secondary metabolites and crude extract was implies on MIC of LB3 have confirmed with lowest concentration of 5.0 mg/mL in broth medium influence of crude extract on growth inhibitory activity after 5 h of incubation period and completed the inhibitory activity at 15 h.ConclusionsThe present study concluded that phylogenetic analysis of endosymbiotic bacteria Enterobacter sp from sponge D. granulosa of Lakshadweep islands showed significant antibacterial activity against clinical bacterial pathogens.     

Antibacterial activity of selected ethnomedicinal plants from South India

ObjectiveTo screen the antimicrobial potential of three ethnomedicinal plants Chassalia curviflora Thw. (C. curviflora), Cyclea peltata Hook. F. &; Thomson (C. peltata) and Euphorbia hirta L (E. hirta) used in folk medicines in Aarukani hills Kani tribe, Tamil Nadu, India against human bacterial pathogens.MethodsAntibacterial efficacy was performed by disc diffusion method against the pathogens viz., Escherichia coli (E. coli) (ATCC 35218), Staphylococcus aureus (S. aureus) (ATCC 6538), Salmonella typhi (S. typhi) (MTCC 733), Proteus vulgaris (P. vulgaris), Proteus mirabilis (P. mirabilis) and Streptococcus pyogenes (S. pyogenes) and incubated for 24 h at 37 °C.ResultsThe maximum degree of antibacterial activity was observed in C. peltata followed by C. curviflora. While E. hirta showed comparatively low degree of antibacterial activity. The methanolic extract of C. peltata showed the antibacterial activity against three pathogens viz., S. pyogenes, P. vulgaris and E. coli with the inhibition zones 12 mm, 10 mm and 9 mm, respectively. hexane extracts of C. peltata also showed the antibacterial activity against two selected pathogens viz., P. vulgaris and P. mirabilis with 15 mm and 12 mm of inhibition zones. All the three different concentrations (0.25, 0.50 &; 0.75 mg/mL) of methanolic extract of C. peltata show the inhibitory effect on the three susceptible bacteria S. pyogenes, P. vulgaris and E. coli with the maximum inhibition in the highest concentration (0.75 mg/mL). The methanolic and hexane extracts of C. curviflora exhibited the antibacterial activity against only one bacterium each i.e. P. vulgaris and S. typhi with the maximum zone of inhibition 13 and 11 mm respectively. The methanolic and hexane extracts of E. hirta exhibited the antibacterial activity against only one bacterium i.e. S. pyogenes with the maximum zone of inhibition 13 and 11 mm respectively.ConclusionsThe present investigation revealed that the C. curviflora, C. peltata and E. hirta are potentially good source of antibacterial agents and demonstrates the importance of such plants in traditional medicines.     

Antibacterial activities of some Indian traditional plant extracts

ObjectiveTo evaluate the in vitro antibacterial activity of various solvent extracts of South Indian traditional medicinal plants Ocimum sanctum, Ocimum gratissimum, Aegle marmelos, and Adhatoda vasica leaves against clinical pathogens of human origin.MethodsThe antimicrobial activity of different solvents crude extract of four medicinal plants used in traditional Indian medicine was tested by disc diffusion method against five bacterial pathogens: Escherichia coli, Staphylococcus aureus, Salmonella typhi, Salmonella paratyphi and klebsiella pneumoniae.. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was determined for evaluating the potential plant extract.ResultsThe antibacterial results showed methanol extracts (0.4 g/ml) of Ocimum gratissimum and Ocimum sanctum showed maximum zone of inhibition (30 mm and 25.5 mm, respectively) against Salmonella typhi. MIC was tested at various concentrations from 0.625 mg/ml to 0.039 mg/ml for all the plant extracts. At the lowest concentration (0.039mg/ml) tested, methanol extracts of Ocimum gratissimum showed higher MIC against Salmonella typhi and Salmonella paratyphi where as the methanolic extracts of Ocimum gratissimum showed potent activity against Staphylococcus aureus at 0.078 mg/ml. Methanol extract (0.4 g/ml) of Aegle marmelos showed significant inhibitory activity of 22.5mm and MIC value of 0.156.mg/ml against E. coli strain. The Klebsiella spp was the most resistant strain of all and various concentrations Adhatoda vasica extract showed less activity against the tested pathogens.ConclusionsThe present screening result demonstrated that the Indian traditional medicinal plants Ocimum sanctum, Ocimum gratissimum, Aegle marmelos methanol leaf extract has potent antibacterial activity and the studied plants may be new source for novel antibacterial compound discovery for treating drugs resistant human pathogens.     

Antibacterial activity of crude ethanolic extract and solvent fractions of Ficus pseudopalma Blanco leaves

ObjectiveTo investigate the antimicrobial properties of Ficus pseudopalma (F. pseudopalma) leaf extracts.MethodsThe antibacterial properties of F. pseudopalma Blanco crude ethanolic leaf extract, and its solvent fractions chloroform (CF), ethylacetate (EF) and water fractions were evaluated through antibacterial agar disc diffusion method and the minimum inhibitory concentration (MIC) was determined. Five Gram-positive and five Gram-negative bacteria were used for the study.ResultsThe zone of inhibitions obtained from the antibacterial agar diffusion disc method showed that CF, and EF exhibited active (14-19 mm) antibacterial activity against Bacillus subtilis UST CMS 1011, and partially active (10-13 mm) antibacterial properties against both Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis ATCC 12228. Water exhibited no antibacterial properties against all microorgranisms tested. The MIC values observed for all Gram-positive bacteria tested were >5 mg/mL, except for Bacillus subtilis whose MIC value was 5 mg/mL for CF and EF fractions. All extracts exhibited no antibacterial activity against Gram-negative bacteria.ConclusionsFrom this study, it can be concluded that F. pseudopalma extracts may be a potential antibacterial agent against Gram-positive bacteria. The antibacterial property may be attributed to flavonoids and terpenoids present in the crude ethanolic extract, CF and EF.     

Efficacy of fresh leaf extracts of Spondias mombin against some clinical bacterial isolates from typhoid patients

ObjectiveTo evaluate the phytochemical properties and antibacterial activity of methanol, acetone, ethanol and aqueous extracts of fresh leaves of Spondias mombin (S. mombin) on some clinical bacterial isolates.MethodsClean and fresh leaves of S. mombin were collected in Ondo, Southwestern Nigeria. The leaves were blended, extracted with methanol, acetone, ethanol and water. The extracts were evaporated to dryness using rotary evaporator and tested for the presence of saponins, tannins, cardiac glycoside, terpenoids, flavonoids, reducing sugars, volatile oils, alkaloids and glycoside. The extract were tested against Gram-negative bacteria Klebsiella pneumonia, Serratia marcescens, Salmonella typhi and Enterobacter aerogens; Gram-positive bacteria Staphylococcus aureus by observing the zones of inhibition using agar well diffusion assay.ResultsThe study showed that the leaves contained saponins, tannins, flavonoids, alkaloids and glycoside. All the solvent extracts showed activity against all the test bacteria. The methanol extract also showed the highest activity against Enterobacter aerogens, zone of diameter (15.00依1.89) mm, while the ethanol extract showed the highest activity against Staphylococcus aureus with zone of diameter (12.50依1.50) mm. The acetone extract showed the highest activity against Salmonella typhi, zone of diameter (17.50依0.29) mm followed by methanol extract showing zone of diameter (15.67依1.01) mm. The acetone extract showed the highest activity against Klebsiella pneumonia (15.17依0.67) mm, while the aqueous extract shows the highest activity against Serratia marcescens (14.67依2.68) mm. The minimum inhibitory concentration of the leaf extracts ranged between 10-90 mg/mL.ConclusionsThis study showed that the aqueous and organic solvents extract of fresh leaves of S. mombin has anti-microbial activity against all the tested organisms.     

Phytochemical constituents and antibacterial efficacy of the flowers of Peltophorum pterocarpum (DC.) Baker ex Heyne

ObjectiveTo investigate the preliminary phytochemistry and antibacterial activity of the flower extract of Peltophorum pterocarpum .MethodsPhytochemical analysis was done by using the standard methods given by Harbone. The methanolic flower extract were tested against Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Salmonella typhi, Serratia marsecens, Acinetobacter baumannii, Enterobacter sp., Proteus mirabilis, Enterococcus faecalis and Streptococcus pyogenes by the agar disc diffusion method.ResultsPreliminary phytochemical screening of flower extract showed the presence of phenolic compounds, flavonoids, saponins, steroids, tannins, xanthoproteins, carboxylic acids, coumarins and carbohydrates. The flower extract of Peltophorum pterocarpum showed significant activity against four gram positive (Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis and Streptococcus pyogenes) and three gram negative bacteria (Proteus mirabilis, Acinetobacter baumannii and Serratia marsecens), out of 12 pathogenic bacteria studied.ConclusionsThe findings of the present study confirm the presence of significant antibacterial activity against human pathogens in the flowers of Peltophorum pterocarpum.     

Evaluation of extracts and essential oil from Callistemon viminalis leaves: Antibacterial and antioxidant activities,total phenolic and flavonoid contents

ObjectiveTo investigate antioxidant and antibacterial activities of Callistemon viminalis (C. viminalis) leaves.MethodsThe essential oil of C. viminalis leaves obtained by hydro-distillation was analyzed by GC/MS. Different extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant (DPPH assay) and antibacterial (agar disc diffusion and 96-well micro-plates methods) actives.ResultsFourteen components were identified in the essential oil, representing 98.94% of the total oil. The major components were 1,8-cineole (64.53%) and α-pinene (9.69%). Leaf essential oil exhibited the highest antioxidant activity of (88.60±1.51)% comparable to gallic acid, a standard compound [(80.00±2.12)%]. Additionally, the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic (tetracycline). The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial strains.ConclusionsIt can be suggested that C. viminalis is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural basis. The present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of C. viminalis leaves exhibited highly significant antibacterial activity against the tested bacterial strains.     

Evaluation of antibacterial activity of selected medicinal plant extracts from south India against human pathogens

ObjectiveThe present study was to evaluate the antibacterial properties of 21 crude extracts from leaf and flower of Aristolochia indica (A. indica), Cassia angustifolia (C. angustifolia), leaf of Catharanthus roseus (C. roseus), Diospyros melanoxylon (D. melanoxylon), Dolichos biflorus (D. biflorus), Gymnema sylvestre (G. sylvestre) and Justicia procumbens (J. procumbens).MethodsThe ethyl acetate, acetone and methanol extract of medicinal plants were evaluated against Gram-positive Bacillus cereus (B. cereus) and Gram-negative bacteria Aeromonas hydrophila (A. hydrophila), Enterobacter aerogenes (E. aerogenes), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) by using well diffusion assay and minimum inhibitory concentration (MIC).ResultsThe crude plant extracts demonstrated broad spectrum activity against all bacteria. The highest inhibitory zone was observed in leaf methanol extract of A. indica against E. aerogenes (25 mm), and E. coli (20 mm), flower methanol extract of C. angustifolia against B. cereus (22 mm) and leaf acetone extract of G. sylvestre against B. cereus (22mm). The MIC values of leaf methanol extract of A. indica against K. pneumonia (22.6μg/ml), and flower extract showed against E. coli (MIC: 24.2μg/ml), leaf ethyl acetate extract of C. angustifolia against K. pneumoniae (MIC: 28.4μg/ml). Acetone ethyl acetate and methanol extracts of D. melanoxylon and D. biflorus showed the lowest MIC activity value of >30 μg/ml against all tested pathogens.ConclusionThe antibacterial activity could be confirmed in most species used in traditional medicine in South India. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents.     

Phytochemical analysis and in vitro antimicrobial activity of Illicium griffithii Hook. f. & Thoms extracts

ObjectiveTo evaluate the antimicrobial activity of hexane, ethyl acetate and methanol extracts of seeds and fruits of Illicium griffithii (I. griffithii)(Family: Schisandraceae).MethodsThe antimicrobial activity of the organic extracts were determined using disc diffusion assay against Gram-positive bacterial strains (three reference cultures and three clinical isolates), Gram-negative bacterial strains (nine reference cultures and six clinical isolates), and six fungi. The primary phytochemical and chemical compositions were analyzed using qualitative chemical analysis and gas chromatography-mass spectrometry respectively.ResultsEthyl acetate extract of fruits was effective against most of the tested reference cultures such as Staphylococcus aureus, Yersinia enterocolitica, Vibrio parahaemolyticus, Bacillus subtilis, Salmonella paratyphi, Enterococcus feacalis, Xanthomonas oryzae and Pseudomonas aerugenosa, whereas methanol extract showed activity only against Staphylococcus aureus, Bacillus subtilis and Xanthomonas oryzae. The hexane and ethyl acetate extracts of fruits were more effective against most of the clinical isolates, whereas methanol extract was effective only against Klebsiella pneumoniae ESBL. The extracts of fruits and seeds did not show any significant antifungal activity against tested fungi. The presence of phenols, tannins, flavonoids, triterpenoids, steroids, alkaloids, saponis and carbohydrates in the different extracts was established. Gas chromatography-mass spectrometry studies on hexane and ethyl acetate extract of fruits resulted in the identification of 31 and 39 compounds respectively.ConclusionsPotent antibacterial phytochemicals are present in ethyl acetate extract of I. griffithii fruits. Further studies are needed to investigate activities of I. griffithii against multidrug resistant bacteria.     

Effect of henna and roselle extracts on pathogenic bacteria

ObjectiveTo investigate the antibacterial effects of water and ethanolic extracts of henna leaves and roselle calyxes against pathogenic bacteria isolated from domestic wastewater.MethodsThe antimicrobial activity was determined in the extracts using agar disc diffusion method. The antibacterial activities of extracts (2.5%, 5.0% and 10.0% w/v) of both henna and roselle were tested against one Gram-positive Bacillius subtilis; two Gram-negative Escherichia coli, Pseudomonas aeruginosa human pathogenic bacteria.ResultsEthanolic extracts had more antimicrobial activity than water extracts. Ethanolic extract of roselle had the highest antibacterial activity against all tested organisms, followed with ethanolic extract of henna. Pseudomonas aeruginosa was the most sensitive bacteria to plant extracts.ConclusionThe results of this study suggested that roselle contains more phyto-chemicals with antimicrobial activity than henna on the bacteria strains under study, and these phyto-chemicals were more effective when extracted by ethanol rather than water.     

Antibacterial activity of ethyl acetate and aqueous extracts of Mentha longifolia L. and hydroalcoholic extract of Zataria multiflora Boiss. plants against important human pathogens

ObjectiveTo determine the potential antibacterial activity of ethyl acetate and aqueous extracts from Mentha longifolia L. (M. longifolia) and hydroalcoholic extract of Zataria multiflora Boiss. (Z. multiflora) against important human pathogens.MethodsPseudomonas aeruginosa, Shigella dysenteriae, Klebsiella pneumoniae (K. pneumonia), Enterobacter cloacae, Salmonella typhi, Proteus mirabilis, Serratia marcescens, Bacillus cereus, Staphylococcus saprophyticus and Staphylococcus aureus were kinds of pathogenic bacteria to determine the antibacterial effect of aqueous and ethyl acetate extracts of M. longifolia and hydroalcoholic extract of Z. multiflora using broth microdiluation method.ResultsThe lowest minimum inhibitory concentration and minimum bactericidal concentration values for K. pneumonia and Pseudomonas aeruginosa (1.25 and 2.5 mg/mL) were observed by the hydroalcoholic extract of Z. multiflora and the lowest minimum inhibitory concentration and minimum bactericidal concentration values for K. pneumonia and Serratia marcescens (2.5 and 5 mg/mL) were observed by the aqueous extracts of M. longifolia.ConclusionsIn conclusion, it seems that Z. multiflora and M. longifolia extracts could inhibit the growth of all of the mentioned bacteria.     

Antibacterial activity and characterization of secondary metabolites isolated from mangrove plant Avicennia officinalis

ObjectiveTo explore antibacterial activity and characterization of secondary metabolites isolated from mangrove plant Avicennia officinalis (A. officinalis).MethodsIn the present study the leaf extracts of A. officinalis were examined for its antibacterial potential using five different solvents against some reference strains of human pathogenic bacteria for the crude extract. Maximum activity was observed for ethyl acetate and hence different concentrations like 15 μL, 25 μL, and 50 μL of ethyl extracts was checked for its antibacterial activity. Partial purification of crude extract was carried by column chromatography and fractions were analyzed using gas chromatography-mass spectrometry (GC-MS) to identify compounds.ResultsThe crude ethyl acetate extracts of A. officinalis showed remarkable antibacterial activity with zones of inhibition of 13 mm against Eschericia coli (E. coli) and 11 mm against Staphylococcus aureus (S. aureus). Fraction 13 (ethyl acetate÷methanol= 8÷2) as the most potent one against with the minimal inhibitory concentration of 30 mm against E. coli and 25 mm against S. aureus. The GCMS resultsof active column fraction (F13) revealed that the active principals were a mixture of hydroxy-4 methoxybenzoic acid, diethyl phthalate, oleic acid.ConclusionsThe leaf extracts with proven antibacterial effects can clearly be directed towards cancer treatment as to inhibiting cancer cell growth. The limited number of test organisms owes to a constraint of resource. So, the effect of strong bursts of leaf extracts on human pathogenic bacteria should further be tested on a wide range of test organisms.     

Evaluation of antimicrobial study in in vitro application of Clerodendrum infortunatum Linn.

ObjectiveTo evaluate the antimicrobial potency of ethanol and chloroform extracts of root, leaf and stem of Clerodendrum infortunatum (Verbenaceae) and to explore a scientific data as this plant was randomly use in traditional medicine to cure common ailments such as intestinal disorder, diarrhea, tuberculosis and respiratory problems, etc.MethodsThe in vitro application was carried out by using disc diffusion, micro broth dilution and serial dilution techniques against clinically important life threatening organisms.ResultsAll the extracts showed significant inhibitory activity over the bacteria and fungus comparable to the standard drug tetracycline and fluconazole. The maximum average diameter zone of inhibition was recorded to bacterial strains against Bacillus megaterium, Salmonella typhi, Klebsiella pneumoniae and to fungi against Aspergillus niger and Candida albicans. The minimum inhibitory concentration values of ethanol leaf extract were determined 64 μg/mL to Bacillus megaterium, Salmonella typhi and Klebsiella pneumoniae; 128 μg/mL to Staphylococcus aureus, Streptococcus-β–haemolyticus and Escherichia coli.ConclusionsThe findings evidently appear promising antibacterial and antifungal properties of Clerodendrum infortunatum against antagonistic pathogens. Leaf possesses quite potent activity than root and stem specially leaf extract>root extract>stem extract. This study serves as basis for further research to lead compounds to be isolated so that it may be as a template for the implications of these results for bioactivity and drug discovery potential of herbal products.     

A survey on Hibiscus rosa—sinensis,Alcea rosea L. and Malva neglecta Wallr as antibacterial agents

ObjectiveTo guide for selection of plants with antibacterial activity for further phytochemical works on the isolation and identification of the active compounds.MethodsEthanolic extracts of 3 species from Malvaceae family were evaluated by agar disc diffusion method for antibacterial activity against some gram-positive and gram-negative bacteria (Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella pneumoniae, Salmonella typhi, Bacillus cereus, Bacillus anthracis, Escherichia coli Streptococcus pyogenes). The extracts were obtained from aerial parts of Hibiscus rosa (H. rosa)-sinensis (leaf and flower), Alcea rosea (A. rosea) L. (leaf and flower) and Malva neglecta (M. neglecta) Wallr (flower).ResultsThese extracts had inhibitory effects at different concentrations (0.05, 0.10, 0.20 and 0.40 g/mL) against above mentioned bacteria. Escherichia coli was the most resistant strain. The highest inhibitory zone was showed by ethanolic extract of M. neglecta against Staphylococcus epidermidis (22 mm) and followed by ethanolic extract from flower of H. rosa against Staphylococcus epidermidis and Staphylococcus aureus (20 mm). The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values against Staphylococcus epidermidis were equal (MIC=MBC=5 mg/mL for M. neglecta extract and for H. rosa extract MIC=MBC=20 mg/mL).ConclusionsThese findings suggest that these native plants have good antibacterial properties that can be used for infection control and treatment and could also be as new source for antibiotics discovery and infection treatment.     

Preliminary study on the antibacterial activity of some medicinal plants of Khuzestan (Iran)

ObjectiveTo search for antimicrobial agents among natural products.MethodsEthanolic extracts of 4 plant species, including Beta vulgaris L. (Chenopodiaceae), Amaranthus graecizans (A. graecizans) L. (Amaranthaceae), Rumex obtusifolius (R. obtusifolius) L. and Polygonum patulum (P. patulum) M.B. (Polygonaceae), were evaluated for antibacterial activity using agar disc diffusion method against some gram-positive and gram-negative bacteria [Pseudomonas aeruginosa (P. aeruginosa), Listeria monocytogenes (L. monocytogenes), Staphylococcus epidermidis (S. epidermidis), Staphylococcus aureus (S. aureus), Klebsiella pneumoniae (K. pneumoniae), Salmonella typhi (S. typhi), Bacillus cereus (B. cereus), Bacillus anthracis (B. anthracis), Escherichia coli (E. coli) and Streptococcus pyogenes (Str. pyogenes)]. These extracts were obtained from aerial parts of the used plants.ResultsThe majority of these extracts had inhibitory effect at different concentrations (0.05 g/mL, 0.10 g/mL, 0.20 g/mL and 0.40 g/mL) against above mentioned bacteria. E. coli was the most resistant strain. The highest inhibitory zone was showed by ethanolic extract of P. patulum against Str. pyogenes (28 mm) and followed by ethanolic extract of B. vulgaris against S. epidermidis (23 mm). The extract of A. graecizans didn't show inhibitory activity except at 0.40 g/mL against B. cereus. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of R. obtusifolius extract that was measured against Str. pyogenes were equal (MIC=MBC=5.00mg/mL).ConclusionThe findings of this study could also be as new source for antibiotics discovery and infection treatment.     

In vitro antibacterial potential of some Vitex species against human pathogenic bacteria

ObjectiveTo study the antibacterial activity of the leaf methanol extracts of five different species of Vitex namely, Vitex altissima (V. altissima), Vitex diversifolia (V. diversifolia), Vitex negundo (V. negundo), Vitex peduncularis (V. peduncularis) and Vitex trifolia (V. trifolia).MethodsAntibacterial assay was carried out by using disc diffusion method, determination of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) against five strains of Gram-positive and seven strains of Gram-negative human pathogenic bacterial strains.ResultsThe results of antibacterial activity of Vitex species showed that the extracts possessed a broad spectrum of antibacterial activity. The V. peduncularis possessed the highest activity against all the microorganisms screened. It produced a zone of inhibition ranged between (11.000 ± 0.577) and (22.670 ± 0.667) mm and the MIC values were from 62.5 to 1 000.0 μg/mL and the MBC values were from 125.0 to 2 000.0 μg/mL.ConclusionsBased on the present study, V. peduncularis is recommended for the isolation of antibacterial molecule responsible for the activity against the tested human pathogenic bacterial strains.     

Enhanced Optical and Antibacterial Activity of Hydrothermally Synthesized Cobalt-Doped Zinc Oxide Cylindrical Microcrystals

Cobalt (Co) doped zinc oxide (ZnO) microcrystals (MCs) are prepared by using the hydrothermal method from the precursor’s mixture of zinc chloride (ZnCl₂), cobalt-II chloride hexahydrate (CoCl₂·6H₂O), and potassium hydroxide (KOH). The smooth round cylindrical morphologies of the synthesized microcrystals of Co-doped ZnO show an increase in absorption with the cobalt doping. The antibacterial activity of the as-obtained Co-doped ZnO-MCs was tested against the bacterial strains of gram-negative (Escherichia coli, Klebsiella pneumonia) and gram-positive bacteria (Staphylococcus aureus, Streptococcus pyogenes) via the agar well diffusion method. The zones of inhibition (ZOI) for Co-doped ZnO-MCs against E. coli and K. pneumoniae were found to be 17 and 19 mm, and 15 and 16 mm against S. Aureus and S. pyogenes, respectively. The prepared Co-doped ZnO-MCs were thus established as a probable antibacterial agent against gram-negative bacterial strains.     

Assessment of in vitro antimicrobial potency and free radical scavenging capacity of the essential oil and ethanol extract of Calycotome villosa subsp. intermedia growing in Algeria

ObjectiveTo assess the antimicrobial and antioxidant activity of the essential oil and ethanol extract of the aerial parts of Calycotome villosa subsp. intermedia growing in the West Northern region of Algeria.MethodsChemical composition of essential oils obtained by hydrodistillation from areal parts of Calycotome villosa subsp. intermedia was investigated using gas chromatography (retention indices) and gas chromatography-mass spectrometry while the antimicrobial activities were determinate by paper disc diffusion method and minimum inhibitory concentration assays tested against four bacterial strains and one yeast and antioxidant activity was evaluated as a free radical scavenging capacity (RSC).ResultsEssential oils were dominated by non-terpenic compounds and fatty acids. However, the phenylpropanoids, monoterpenes and sesquiterpenes components were only present in small percentages. The most important antibacterial activity of essential oil was expressed on Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae and Salmonella typhimurium. Antioxidant activity was evaluated as a RSC. RSC was assessed by measuring the scavenging activity of essential oil and ethanol extract on 1,1-diphenyl-2-picrylhydrazil (DPPH). Investigated ethanol extract reduced the DPPH radical formation (IC₅₀=68 μg/mL).ConclusionResults in this experiment indicate that the essential oil and the ethanol extract display antibacterial activity against two Gram-positive bacteria and activity to a lesser extent against two Gram-negative species. They may be a new potential source of components, which are likely to have impact on human health.     

In vitro antibacterial activity of Desmodium gangeticum (L.) DG

ObjectiveTo identify the antibacterial activity of Desmodium gangeticum (D. gangeticum).MethodsAntibacterial activity of D. gangeticum was tested with various solvents viz., methanol, ethanol, chloroform and aqueous extract against various bacterial pathogens such as Klebsiella pneumoniae, Escherichia coli, Salmonella typhi, Streptococcus mutants and Pseudomonas aeruginosa. Antibiotic sensitivity assay was performed with amoxicillin, kanamycin, tetracyclin, ciprofloxacin and penicillin.ResultOf the selected several extract, the methanolic extract showed maximum zone of inhibition (24±2.3mm) against S. mutants and minimum zone of inhibition was observed with aqueous extract against P. aeruginosa (7±0.08). In addition the antibiotic sensitivity was observed with kanamycin, tetracyclin, ciprofloxacin against all bacterias.ConclusionsThe methonalic extract of D. gangeticum be able to use as potential antibacterial source for various infective pathogens.