Antibacterial Activity of Jordanian Medicinal Plants

The antibacterial activity of ethanol extracts of 15 plant species used in the traditional medicine in Jordan and other Middle East countries were tested. Extracts of certain parts of these plants were tested in vitro against 14 pathogenic bacterial species and strains using the agar diffusion method. Results evaluated as the diameter of inhibition zone of bacterial growth showed that 25 mg/well of 12 plant extracts have antibacterial activity on one or more of the tested bacteria. Three plants exhibited broad spectrum antibacterial activity: Punica granatum L., Quercus infectoria Olive., and Rhus coriaria L. The most susceptible bacteria were Pseudomonas aeruginosa, Bacillus cereus and Streptococcus pyogenes (ATCC 12351), and the most resistant species were Escherichia coli (ATCC 25922 and clinical isolates), Klebsiella pneumoniae, Shigella dysentriae (ATCC 49345), and Yersinia enterocolitica (ATCC 9610). The minimum inhibitory concentrations (MIC) of active extracts ranged from 4-32 mg/ml while the minimum bactericidal concentrations (MBC) were exerted at higher doses 8-62 mg/ml.     

Study on the antibacterial potential of physalis minima linn

Physalis minima is an important medicinal plant of Indian System of Medicine. This plant is reported for its diuretic, laxative and antiinflammatory activities. However, the plant is not well scrutinized for its antimicrobial potential. The major chemical constituents reported from the plant are phenolics and alkaloids, which suggest that the plant may turn out to be a potent antiinfective agent. The aim of the study was to find out the antibacterial potential of mature berries of P. minima using streak plate, well diffusion, determination of minimum inhibitory concentration and bioautographic methods against a battery of Gram positive and Gram negative bacterial strains. Results of the study showed that methanol and chloroform extracts of P. minima exhibited potent inhibitory activity against all the bacterial strains tested. Minimum inhibitory concentration found out was 100 μg in both the extracts. Bioautography assay showed polar compounds present in the crude extract are responsible for the antimicrobial action.     

Inhibition of Staphylococcus Aureus Mediated by Extracts from Iranian Plants

In order to find new antibacterial agents effective against Staphylococcus aureus, ethanolic extracts of 10 plants were tested. S. aureus (489 samples) were isolated either from healthy carriers (nose and throat) or clinical samples. Out of 489 isolates tested, 98.6% were sensitive to trimethoprim-sulfamethoxazole which was used as the reference antibiotic. From the plant extracts screened for antibacterial activity, Myrtus communis L. (leaves) had the greatest activity, inhibiting the growth of 99% of the isolates. Glycyrrhiza glabra L., Eucalyptus globolus Labill and Menta viridis L., were also active against the isolates inhibiting the growth of 90, 59.5 and 48.7% of the isolates, respectively. All of these extracts were active against the reference strains of S. aureus tested. Saturia hortensis L., Teucrium polium L., and Achillea santolina L., had very little antibacterial activity, while Trigonella foenum graecum L., Echium amoenum Fisch & Mey (flowers) and Juglans regia L. (leaves), had no antibacterial activity against the bacterial isolates.     

Essential Oil Composition and Antibacterial Studies of Vitex negundo Linn. Extracts

Essential oils from fresh leaves, flowers and dried fruits of Vitex negundo were obtained by hydrodistillation. Using Soxhlet extractor five successive extracts from dried and powdered leaves were also taken. The chemical constituents of essential oil of leaves, flowers and dried fruits were analyzed by GC-FID and GC/MS techniques. Main constituents identified in leaves oil were δ-guaiene, carryophyllene epoxide and ethyl-hexadecenoate; in flowers oil - α-selinene, germacren-4-ol, carryophyllene epoxide and (E)-nerolidol while fruit oil showed β-selinene, α-cedrene, germacrene D and hexadecanoic acid as the main constituents. β-Caryophyllene was only the constituent identified as common to all three oils. α-Guaiene and guaia-3,7-diene were identified as common constituents in leaf and dried fruit oil while leaf and flower oils showed p -cymene, valencene, caryophyllene epoxide and (E)-nerolidol as common constituent. All the essential oils and successive extracts were evaluated for antibacterial potential against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa bacterial strains. Each of the essential oils and extracts were found to give promising results against B. subtilis and E. coli. Ethyl acetate and ethanol extracts showed prominent antibacterial activity against all the tested strains. Fruits and leaves oil were found to be most active against E. coli and S. aureus, respectively. Only flowers oil was found to be active against P. aeruginosa.     

Anti-Salmonella activity of medicinal plants from Cameroon

OBJECTIVES: To evaluate the effects of herbal extracts derived from plants commonly prescribed by traditional practitioners for the treatment of typhoid fever. DESIGN: A cross sectional study. SETTING: Departments of Life Sciences and Chemistry, University of Buea, Cameroon. SUBJECTS: Methanol extracts of plant parts commonly used in Cameroon for the treatment of typhoid fever. MAIN OUTCOME MEASURES: Antimicrobial activity was tested using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assays. RESULTS: Methanol extracts of plant parts commonly used in Cameroon for the treatment of typhoid fever were tested for antibacterial activity against Salmonella typhi, S. paratyphi and S. typhimurium. The formulations used were: 1) Formulation A comprising Cymbogogon citratus leaves, Carica papaya leaves, and Zea mays silk. 2) Formulation B comprising C. papaya roots, Mangifera indica leaves, Citrus limon fruit and C. citratus leaves. 3) C. papaya leaves. 4) Emilia coccinea whole plant. 5) Comelina bengalensis leaves. 6) Telfaria occidentalis leaves. 7) Gossypium arboreum whole plant. Antimicrobial activity was tested using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assays. Generally, Formulation A elicited inhibitory activity at a lower range of 0.02 to 0.06 mg/ml. Similarly, Formulation B elicited bacterial activity at the lowest range of 0.06 to 0.25 mg/ml. C. bengalensis leaves on the other hand, showed the lowest activity with a concentration range of 0.132 to 2.0 mg/ml and 1 to 4 mg/ml in MIC and MBC assays respectively. S. paratyphi was most sensitive to the formulations (concentration range of 0.02 to 1 mg/ml in both MIC and MBC assays) while S. typhimurium was the least sensitive and concentrations of up to 4 mg/ml were required to be bactericidal. CONCLUSION: It is concluded that plant extracts with low MIC and MBC values (1 mg/ml and lower) may contain compounds with therapeutic activity.     

Antimicrobial Activity of Goniothalamus Grandiflorous

The extracts of stem bark, leaves and flowers of Goniothalamus grandiflorous were screened against six Gram positive and six Gram negative bacteria, a parasite, and four fungi. All extracts were found to be active against all the bacteria and some fungi. The flower and the leaf extracts exhibited a superior level of antibacterial activity. The flower and bark extracts were active against T. mentagrophytes. Isoaltholactone isolated from the leaves, was the active principle and exhibited a good level of activity against the tested organisms.     

Antibacterial and Antifungal Potential of some Arid Zone Plants

Sequential extracts of some medicinally important arid zone plants of Rajasthan, viz. Lepidagathis trinervis Nees., Polycarpea corymbosa Lam. and Sericostoma pauciflorum Stocks. ex Wight. were tested against six bacterial (Gram +ve and Gram -ve) and five fungal strains using agar well diffusion method. Ethyl acetate extract of L. trinervis showed maximum activity against Bacillus subtilis, Enterobactor aerogenes, Pseudomonas aeruginosa, Aspergillus flavus and Trichophyton rubrum (inhibition zone 16.00±0.81, 13.33±0.66, 14.33±1.85, 14.30±0.34 and 23.00±0.00 mm) at varied minimum inhibitory concentrations of 82, 20, 41, 41 and 20 μg/ml, respectively.     

Antibacterial activities of some selected plant extracts of local herbal medicines in Lahore-Pakistan

The antibacterial activity of methanol and acetone extracts of five plant extracts being utilized for the cure of different ailments in Pakistan was studied.The extracts of Curcuma zedoaria,Ipomea turpethum,Sphaeranthus indicus,Terminalia chebula and Tricholepis glaberrima were tested against seven different bacterial strains by well diffusion method and microdilution methods.The pattern of zone of inhibition varied with the plant extracts,the solvent used for extraction and organisms tested.Plant extracts(20 mg/mL) were used to evaluate antibacterial activities.The zone of inhibition exhibited by methanol extracts varied between 11 mm and 32 mm while those of acetone extracts varied between 9 mm and 25 mm respectively.The minimum inhibitory concentration(MIC) exhibited by methanol extracts ranged between(18.4-51.1) mg/mL.Overall methanolic extracts showed more activity than the acetone extracts against tested organisms except for S.indicus.The plants were also analyzed for their elemental composition using atomic absorption spectrophotometer to explore natural sources of essential elements that can be utilized for medicinal purposes.     

Synthesis and in vitro antibacterial activity of schiff bases of N-substituted isatins as effective scaffolds

Novel Schiff bases of N-substituted isatin, 1–13, were synthesized starting from isatin and N-(4-amino-2-methylphenyl)-4-chlorophthalimide and their structures were confirmed by spectral and elemental analyses. All new compounds were tested for their in vitro antibacterial activity against a range of Gram +ve bacterial strains, like Bacillus subtilis (NCIM-2156), Staphylococcus aureus (NCIM-2079) and Staphylococcus epidermis (NCIM-2493) and Gram ?ve bacterial strains, like Pseudomonas aeruginosa (NCIM-2036), Escherichia coli (NCIM-2065) and Proteus vulgaris (NCIM-2027) following broth dilution method as recommended by the National Committee for clinical laboratory standards using ciprofloxacin as reference. Determination of minimum inhibitory concentration (MIC) and zone of inhibition showed that the molecules were more active against Gram ?ve bacteria than Gram +ve bacteria. The compounds showed promising antibacterial properties with MIC ranging between 10 and 30 μg/mL.     

Composition and antibacterial activity of the essential oils from Zanthoxylum rhoifolium

The essential oils from the aerial parts of leaves, fruits and flowers of Zanthoxylum rhoifolium of Southern Brazil (Rio Grande do Sul), were analysed by GC, GC/MS, and chiral phase gas chromatography (CPGC). Forty-eight compounds were identified from the essential oils. The major constituents of the essential oil of the leaves were germacrene D (34 %) and bicyclogermacrene (23 %) and of the fruits, menth-2-en-1-ol (46.2 %), beta-myrcene (30.2 %), (-)-linalool (15 %) and (-)-alpha-terpineol (8.45 %). beta-Myrcene (65 %) and menth-2-en-1-ol (5.4 %) dominate the essential oil of the flowers. The oils of the leaves and fruits were bioactive with antibacterial activity against Staphylococcus aureus (Gram positive), and Klebsiella pneumoniae and Salmonella setubal bacteria (Gram negative) microorganisms, while the essential oil of the flowers was inactive.     

In vitro activity of Brazilian medicinal plants,naturally occurring naphthoquinones and their analogues,against methicillin-resistant Staphylococcus aureus

Fourteen extracts from Brazilian traditional medicinal plants used to treat infectious diseases were used to look for potential antimicrobial activity against multiresistant bacteria of medical importance. Staphylococcus aureus strains were susceptible to extracts of Punica granatum and Tabebuia avellanedae. The minimum inhibitory concentrations (MICs) of the total extracts and of additional fractions of these plants were determined by employing strains of methicillin-resistant (MRSA) and -sensitive (MSSA) S. aureus, including isolates of the PFGE clone A, which is prevalent in Brazil and two ATCC reference strains. A mixture of ellagitannins isolated from P. granatum and two naphthoquinones isolated from T. avellanedae demonstrated antibacterial activity against all S. aureus strains tested. Semi-synthetic furanonaphthoquinones (FNQs) showed lower MICs than those exhibited by natural occurring naphthoquinones. The results indicate that these natural products can be effective potential candidates for the development of new strategies to treat MRSA infections.     

Antibacterial Activity of some Medicinal Mangroves against Antibiotic Resistant Pathogenic Bacteria

The antibacterial activity of the leaves and bark of mangrove plants, Avicennia marina, A. officinalis, Bruguiera sexangula, Exoecaria agallocha, Lumnitzera racemosa, and Rhizophora apiculata was evaluated against antibiotic resistant pathogenic bacteria, Staphylococcus aureus and Proteus sp. Soxhlet extracts of petroleum ether, ethyl acetate, ethanol and water were prepared and evaluated the antibacterial activity using agar diffusion method. Most of the plant extracts showed promising antibacterial activity against both bacterial species. However, higher antibacterial activity was observed for Staphylococcus aureus than Proteus sp. The highest antibacterial activity was shown by ethyl acetate of mature leaf extracts of E. agallocha for Staphylococcus aureus. All ethyl acetate extracts showed higher inhibition against S. aureus while some extracts of chloroform, ethyl acetate and ethanol gave inhibition against Proteus sp. None of the petroleum ether and aqueous extracts showed inhibition against Proteus sp. All fresh plant materials did also show more antibacterial activity against both bacterial strains than did dried plant extracts. Antibacterial activity of fresh and dried plant materials reduced for both bacterial strains with time after extraction. Since L. racemosa and A. marina gave the best inhibition for bacterial species, they were used for further investigations. Charcoal treated plant extracts of L. racemosa and A. marina were able to inhibit both bacterial strains more than those of untreated plant extracts. Phytochemical screening of mature leaf, bark of L. racemosa and leaf extracts of A. marina has been carried out and revealed that leaf and bark contained alkaloids, steroids, triterpenoids and flavonoids. None of the above extracts indicate the presence of saponins and cardiac glycosides. Separated bands of extracts by TLC analysis showed antibacterial activity against S. aureus.     

Evaluation of antimicrobial efficacy of flavonoids of withania somnifera L

In the present study antimicrobial activity of Withania somnifera L. Dunal (Solanaceae) has been evaluated against selected pathogens. Free and bound flavonoids of different parts (root, stem, leaf and fruit) of W. somnifera have been studied for their antimicrobial activity using disc diffusion assay against three Gram negative bacteria (Escherichia coli MTCC 46, Proteus mirabilis MTCC 3310 and Pseudomonas aeruginosa MTCC 1934), one Gram positive bacteria (Staphylococcus aureus MTCC 3160) and three fungi (Candida albicans MTCC 183, Aspergillus flavus MTCC 277 and Aspergillus niger MTCC 282). Minimum inhibitory concentration (MIC) of the extracts was evaluated through micro broth dilution method, while minimum bactericidal/fungicidal concentration was determined by sub culturing the relevant samples. C. albicans was found to be the most susceptible organism followed by S. aureus, P. mirabilis, E. coli and P. aeruginosa. Out of the tested organisms, A flavus and A. niger were observed to be resistant as none of the tested extracts showed activity against them. Total activity (TA) of extracts (ml/g) against each sensitive pathogens was also evaluated. Bound flavonoid extract of root showed best activity against C. albicans (IZ 30, MIC 0.039, MFC 0.039, respectively). However all the microorganisms were found to be sensitive against the extracts tested. Total activity of bound flavonoid extract of root was found to be same for E.coli, P. mirabilis, S. aureus and C. albicans (153.84 ml/g). Results of the present study reveal that extracts of W. somnifera showing great antimicrobial potential against test microorganisms may be exploited for future antimicrobial drugs.     

Effects of Methanol Extract of Wedelia chinensis Osbeck (Asteraceae) Leaves against Pathogenic Bacteria with Emphasise on Bacillus cereus

The antibacterial activity of the methanol extract of Wedelia chinensis leave was studied and tested against three pathogenic Gram positive bacteria (Bacillus cereus, B. subtilis and Stapylococcus aureus) and three pathogenic Gram negative bacteria (Escherichia coli, Proteus rettgeri and Pseudomonas aeruginosa) by the disk diffusion assay and broth dilution methods. The extract exhibited favourable antibacterial activity against the bacterial cells but was more potent against Gram positive bacteria with the minimum inhibition concentration of 3.12 to 6.25 mg/ml compared to the Gram negative bacteria which had minimum inhibition concentration values of 25 mg/ml. The time-kill study suggested that the extract possessed bactericidal properties at higher concentrations and eradicated the growth of bacterial cells. The major abnormalities occurred to the bacterial cells after exposed to the extract were complete alterations in their morphology and collapsed of the cells beyond repair. The methanol extract of W. chinensis may be an effective antibacterial agent to treat bacterial infections.     

Antibacterial and antifungal activities of extracts of combretum molle

OBJECTIVE: In traditional medical practices of Ethiopia the aqueous extracts obtained from the stem bark of Combretum molle (R. Br. Ex. G. Don.) Engl & Diels (Combretaceae) have a longstanding reputation for the treatment of liver diseases malaria and tuberculosis. Owing to the widespread traditional uses of this plant, the studyinvestigated the antimicrobial activity the bark extract of this plant against Gram positive and and Gram negative bacteria. METHODS: Petroleum ether, dichloromethane and acetone fractions of the bark of the plant were prepared by soxhlet extraction and screened for their antimicrobial activity. The acetone fraction exhibited a powerful activity and was therefore further tested against twenty-one bacterial and six fungal strains. The minimum inhibitory concentration (MIC) of this extract was determined by checker board technique using nutrient agar medium. The zones of inhibition produced by the extract against bacteria and fungi were determined and compared by disc diffusion technique with those of pure ciprofloxacin and griseofulvin, respectively. RESULTS: The highest antibacterial action of the acetone extract was against the Gram negative organisms EscherIchia coli and Shigella spp with an MIC value of 50 mg/ml. The activity of the extract against these bacteria was comparable to that of ciprofloxacin when assessed by the disc diffusion technique. Among the fungal strains tested Candida albicans showed high susceptibility to the extract and growth was completely inhibited at a concentration of 400 microg/ml. At the same concentration, the acetone extract and the standard antifungal drug griseofulvin produced comparable zones of inhibition on C. albicans. Studies on the mode of action of the extract indicated that it was bactericidal and fungicidal. The antimicrobial activity of the extract was attributed to the high amount of hydrolysable tannins present in the bark of the plant. CONCLUSION: The acetone extract of the stem bark of C. molle has the potential for use as a natural antimicrobial agent. Further in vivo antimicrobial, phytochemical and toxicological studies are requireed to evaluate the chemotherapeutic effect of the plant.     

Bio-efficacy of Dioscorea pentaphylla from Midmid-Western Ghats, India

Antibacterial and antifungal activity of crude extracts of medicinally important and traditionally used yam plant, Dioscorea pentaphylla, from mid-Western Ghats was evaluated against 27 bacterial and 5 fungal clinical strains collected of the patients from infectious sources. The clinical strains belonging to their respective species showed concentration-dependent susceptibility toward crude petroleum ether extract, chloroform extract and methanol extract at 100 μg/100 μl. The extracts exhibited predominant antibacterial activity against Staphylococcus aureus (ATCC-20852), Pseudomonas aeruginosa (ATCC-29737) and Klebsiella pneumoniae (MTCC-618), respectively, and five clinically isolated pathogenic fungi, Trichophyton rubrum, Microsporum gypseum, Tricophyton tonsurans, Microsporum audouini, and Candida albicans, with antibacterial drug ciprofloxacin and antifungal drug fluconozole (50 μg/100 μl) as standards. Out of the three extracts, ethanol extracts possessed better minimum inhibitory concentration (MIC) against all the bacterial strains. All the three extracts showed significant activity against all the five fungal pathogen strains. The results are promising and support the traditional use of D. pentaphylla for the treatment of bacterial and fungal infections.     

Antibacterial activity of some African medicinal plants used traditionally against infectious diseases

Context: Plants are known to play a crucial role in African traditional medicine for the treatment of infection diseases.

Objectives: To investigate the claimed antimicrobial properties of plants traditionally used in African countries, providing scientific validation for their use.

Materials and methods: Eighty-three polar and non-polar extracts from 22 medicinal plants were screened for their antibacterial activity against Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae) and Mycobacterium smegmatis using the broth microdilution method.

Results and Discussion: In vitro antibacterial activity against one or more tested bacteria was shown by 83% of the extracts. The highest activity was obtained with the methanol extracts of the aerial parts of Acacia karroo Hayne (Fabaceae) and Anacardium occidentale L. (Anacardiaceae) and the roots of Bridelia cathartica G. Bertol (Euphorbiaceae), against S. aureus (minimum inhibitory concentration (MIC)?=?7.5 µg/mL). The same MIC values were exhibited against E. faecalis by the methanol extract of A. occidentale, the dichloromethane and methanol extracts of B. cathartica and the ethyl acetate extract of Momordica balsamina l. (Curcubitaceae) leaves. Gram-negative bacteria were less sensitive; the growth of P. aeruginosa was significantly inhibited (MIC?=?31 µg/mL) by the n-hexane and methanol extracts of Gomphocarpus fruticosus (l.) Ait. (Asclepiadaceae) fruits and by the dichloromethane extract of Trichilia emetica Vahl (Meliaceae) seeds. Most of the active extracts were rich in fenols/flavonoids.

Conclusion: This study supports the use of most of the studied plants in traditional medicine, for the treatment of infectious diseases. Some of them are worthy of further investigation.     

GUINEA-BISSAU'S PLANTS: IN VITRO SUSCEPTIBILITY STUDIES ON NEISSERIA GONORRHOEAE

Abstract

Extracts from different parts of Cassia sieberiana, Chamaechrista nigricans, Guiera senegalensis, Lippia chevalieri, Pavetta oblongifolia, Piliostigma thonningii, Senna podocarpa and Terminalia macroptera were examined for in vitro antibacterial activity. These species were collected in the Contúboel region (Guinea-Bissau) which were used by the traditional healer's of the Fulani ethny to treat several disorders including venereal diseases (Diniz, 1996). Fifteen plant extracts were tested against nine strains of Neisseria gonorrhoeae, including penicillin and tetracycline resistant strains. All the extracts exhibited antibacterial activity against all the tested strains. Two of the most active extracts (from Guiera senegalensis leaves and Terminalia macroptera root) were partitioned with different solvents and tested for antiNeisseria gonorrhoeae activity.

     

Antimicrobial Studies on Extracts of Four Species of Stachys

The antimicrobial activity of the methanol extracts of the dried flowering aerial parts of Stachys byzantina, S. inflata, S. lavandulifolia and S. laxa (Labiatae) were studied using the disc diffusion method and determination of minimum inhibitory concentration (MIC) values against Staphylococcus aureus, Streptococcus sanguis, Escherichia coli, Pseudomonas aeroginosa, Klebsiella pneumoniae, Aspergilus niger and Candida albicans. The extracts of plants exhibited concentration-dependent antibacterial activity against the bacteria tested. The extracts were more active against Gram-positive microorganisms. The extracts, however, did not show any antifungal activity.     

In vitro bactericidal activities of new oral penem, faropenem against the various clinical isolates]

The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of faropenem (FRPM) more compared with those of various oral beta-lactams against 15 isolates each of 6 species of microorganism. FRPM possessed potent in vitro antibacterial activity against both aerobic and anaerobic Gram-positive bacteria tested. FRPM showed the same activity as new oral cephems such as cefdinir, cefditoren and cefcapene against all Gram-negative bacteria, but K. pneumoniae strains were less susceptible. The MBC of FRPM against S. pneumoniae and the other strains tested equal and were within 1 dilution the MIC of that, respectively. These results suggest that FRPM has excellent in vitro bactericidal activity against clinical isolates and is a clinically useful for the chemotherapy of bacterial infections.