Screening of some indigenous Qatari medicinal plants for antimicrobial activity

Aqueous, ethanol and butanol crude extracts of the aerial parts of ten plants exhibited variable degrees of antimicrobial activity against four bacterial and two fungal species. Aqueous extracts had low antimicrobial activity against E.coli, P.aeruginosa, B. cerreus, S.aureus, C.albicans and A.flavus. Avicennia marina (AM) aqueous extract exhibited a moderate antifungal activity. Ethanol and butanol crude extracts exhibited an improved antimicrobial activity. However, butanol exhibited a superior antimicrobial activity compared with aqueous and ethanol crudes. Compared with the standard antibiotics tested the butanol extract had the highest activity. Butanol extracts at 2000 microg/disc of AM, Lotus halophilus (LA), Pulicaria gnaphaloides (PG) and Capparis spinosa (CS) had a very good antibacterial activity against both gram-positive and -negative bacteria as well as moderate to good antifungal activity against C. albicans and A. flavus. Medicago laciniata (ML), Limonium axillare (LA) and (PG) butanol crude extract compared with standard chloramphenicol, tetracycline and nalidixic acid exhibited a superior antifungal activity.     

Antimicrobial activity of extracts of herbal plants used in the traditional medicine of Jordan.

Petroleum ether, ethanol, butanol, and aqueous crude extracts of the whole aerial parts of nine plants exhibited variable degrees of antimicrobial activity against four bacterial and three fungal species. Methanol and hexane extracts did not show any activity. Compared with standard antibiotics, extracts had low to moderate activity. The activity spectrum is wide against gram-positive and negative bacteria as well as fungi tested. However, the butanol extracts at 4 mg/disc of Ononis spinosa (OS), Bryonia syriaca (BS) had high moderate antifungal activity against Aspergillus flavus, Fusarium moniliforme and Candida albicans relative to miconazole nitrate at 40 microg/disc. Furthermore, higher antibacterial activity was observed though low to moderate compared with streptomycin and very comparable with chloramphenicol. Cyclaman persicum (CP) petroleum ether extracts only exhibited pronounced antibacterial activity.     

Evaluation of the flora of northern Mexico for in vitro antimicrobial and antituberculosis activity

The aim of the present study was to evaluate the potential antimicrobial activity of 14 plants used in northeast México for the treatment of respiratory diseases, against drug-sensitive and drug-resistant strains of Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae type b and Mycobacterium tuberculosis. Forty-eight organic and aqueous extracts were tested against these bacterial strains using a broth microdilution test. No aqueous extracts showed antimicrobial activity, whereas most of the organic extracts presented antimicrobial activity against at least one of the drug-resistant microorganisms tested. Methanol-based extracts from the roots and leaves of Leucophyllum frutescens and ethyl ether extract from the roots of Chrysanctinia mexicana showed the greatest antimicrobial activity against the drug-resistant strain of Mycobacterium tuberculosis; the minimal inhibitory concentration (MIC) were 62.5, 125 and 62.5 microg/mL, respectively; methanol-based extract from the leaves of Cordia boissieri showed the best antimicrobial activity against the drug-resistant strain of Staphylococcus aureus (MIC 250 microg/mL); the hexane-based extract from the fruits of Schinus molle showed considerable antimicrobial activity against the drug-resistant strain of Streptococcus pneumoniae (MIC 62.5 microg/mL). This study supports that selecting plants by ethnobotanical criteria enhances the possibility of finding species with activity against resistant microorganisms.     

Chemical constituents and antimicrobial activity of medicinal plants from Ghana: Cassia sieberiana, Haematostaphis barteri, Mitragyna inermis and Pseudocedrela kotschyi

The antimicrobial activity of the sequential n-hexane, acetone and 50% aqueous methanol extracts of leaves, stem bark and roots of four species of medicinal plants, Cassia sieberiana DC. (Leguminosae), Haematostaphis barteri Hook. f. (Anacardiaceae), Mitragyna inermis (Willd.) O. Kuntze (Rubiaceae) and Pseudocedrela kotschyi (Schweinf.) Harms (Meliaceae), from Ghana were tested against Bacillus subtilis, Pseudomonas syringae and Cladosporium herbarum using TLC direct-autobiographic methods. Extracts from leaves, stem bark and roots of the four species gave a positive result against at least one test organism. Twelve of the 36 extracts were active against B. subtilis, four extracts were active against P. syringae and six were active against C. herbarum. Preliminary chemical analysis revealed the presence of flavonoids, stilbenes and alkaloids. This is the first report of a stilbene from the Anacardiaceae.     

Antimicrobial and antioxidant activities of traditional Thai herbal remedies for aphthous ulcers

Four medicinal plants (Quercus infectoria, Kaempferia galanga, Coptis chinensis and Glycyrrhiza uralensis) as well as one traditional Thai treatment for aphthous ulcers based on these four plants were tested for antimicrobial activity. MIC values for a range of bacteria and Candida albicans were determined, with both type strains and clinical isolates being used. Antioxidant activity was determined using the ABTS radical scavenging assay. Among the four plants, Q. infectoria showed antimicrobial activity against Staphylococcus aureus with an MIC of 0.41 mg/mL, while C. chinensis showed antifungal activity against C. albicans with an MIC of 6.25 mg/mL. Activity was also shown against a range of other organisms including Salmonella typhi, Serratia marcescens, Vibrio cholerae, Vibrio parahaemolyticus, Pseudomonas aeruginosa and Enterococcus faecalis. The antimicrobial activity of the traditional aphthous ulcer preparation (a powder) was comparable to that for the individual plant extracts, however, incorporation of the powder into a gel formulation resulted in the loss of almost all activity. All extracts, with the exception of K. galanga, also showed good antioxidant activity. This study supports the traditional use of these plants and suggests that they may also be useful in the treatment of other infections.     

Antioxidant, antimicrobial and cytotoxic activities of selected medicinal plants from Yemen

Ninety crude extracts, including dichloromethane, methanol and aqueous extracts from 30 medicinal plants used in the Yemeni ethnomedicine to treat common infections, were screened in vitro for antimicrobial activities against three Gram-positive bacteria and two Gram-negative bacteria, Candida maltosa and five opportunistic human fungal pathogens (two yeasts, three hyphomycetes). Most of the plants showed antibacterial activities. Extracts from Tamarindus indica flowers and Ficus vasta fruits have been the most active. Of the 30 plants tested, 13 showed antifungal activity (40%) against one ore more human pathogenic fungi. The strongest inhibition was exhibited by Azima tetracantha (fruits), Sansevieria ehrenbergii (fruits) and Solanum incanum (fruits). Ten methanol extracts, especially those of Acacia asak barks and Solanum nigrum fruits, showed effective free radical scavenging activities in the DPPH assay. Remarkable cytotoxic activity against FL-cells was shown only for five plants, among them Plicosepalus curviflorus (stems).     

Antimicrobial activity of certain Indian medicinal plants used in folkloric medicine

Fifty medicinal plants belonging to 26 families were studied for their antimicrobial activity. Among 50 plants tested, 72% showed antimicrobial activity. About 22 plant extracts from 15 families exhibited activity against both Gram-positive and Gram-negative bacteria. Fourteen plants belonging to 11 families did not show activity against any of the bacteria tested. Only nine plant extracts showed antifungal activity. The bulb extracts of A. cepa and A. sativum exhibited activity against both filamentous and non-filamentous fungus. Eight plant extracts belonging to seven families exhibited both antibacterial and antifungal activity.     

Antimicrobial activity of 20 plants used in folkloric medicine in the Palestinian area

Ethanolic and aqueous extracts of 20 Palestinian plant species used in folk medicine were investigated for their antimicrobial activities against five bacterial species (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa) and one yeast (Candida albicans). The plants showed 90% of antimicrobial activity, with significant difference in activity between the different plants. The most antimicrobially active plants were Phagnalon rupestre and Micromeria nervosa, whereas, the least active plant was Ziziphus spina-christi. Only ten of the tested plant extracts were active against C. albicans, with the most active from M. nervosa and Inula viscosa and the least active from Ruscus aculeatus. Of all extracts the ethanolic extract of M. nervosa was the most active, whereas, the aqueous extract of Phagnalon rupestre was the most active of all aqueous extracts tested. The ethanolic extracts (70%) showed activity against both Gram positive and negative bacteria and 40% of these extracts showed anticandidal activity, whereas, 50% of the aqueous extracts showed antibacterial activity and 20% of these extracts showed anticandidal activity.     

Antimicrobial activity of selected plants employed in the Spanish Mediterranean area

Eighty-one plants from the Spanish Mediterranean area employed as antimicrobial agents in folk medicine have been identified. The in vitro antimicrobial activity of chloroform and methanol extracts of the plants were studied using the agar dilution method against six selected microorganisms. Thirty extracts had activity against some of the microorganisms tested. Bioautography showed that the antimicrobial activity is probably due to flavonoids, terpenoids and phenolic acids.     

In vitro antimicrobial activity of certain medicinal plants from eastern Ghats, India, used for skin diseases

The paper deals with ethnopharmacological and antimicrobial properties of certain medicinal plants used by adivasi tribes of the Eastern Ghats of Andhra Pradesh, India. Ethanolic extracts of 23 crude drug samples used for various skin diseases were assayed for antimicrobial activity against four bacterial and one fungal human pathogens.     

In vitro antimicrobial activity of extracts of four Achillea species: the composition of Achillea clavennae L. (Asteraceae) extract

The extracts of aerial parts of Achillea clavennae, Achillea holosericea, Achillea lingulata and Achillea millefolium (hexane:ether:methanol=1:1:1) have been tested for antimicrobial activity in a disk diffusion assay against five bacteria (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis) and two fungi (Aspergillus niger and Candida albicans). Extracts of all four species possessed a broad spectrum of antimicrobial activity against all tested strains. The composition of the extract of Achillea clavennae, which showed the strongest activity, was investigated and the structures of isolated compounds were elucidated by spectral means (1D and 2D NMR, UV, IR and MS). The extract yielded alkanes, fatty acids, monoterpenes, guaiane sesquiterpenes (rupicolin A and B, 1-deoxy-1alpha-peroxy-rupicolin A and B), and flavonoids (apigenin and centaureidin). This study confirms the ethnopharmacological use of plants from this genus and places Achillea clavennae L. on the same level as the recognized Achillea millefolium.     

Antimicrobial and phytochemical studies on 45 Indian medicinal plants against multi-drug resistant human pathogens

Ethanolic extracts of 45 Indian medicinal plants traditionally used in medicine were studied for their antimicrobial activity against certain drug-resistant bacteria and a yeast Candida albicans of clinical origin. Of these, 40 plant extracts showed varied levels of antimicrobial activity against one or more test bacteria. Anticandidal activity was detected in 24 plant extracts. Overall, broad-spectrum antimicrobial activity was observed in 12 plants (L. inermis, Eucalyptus sp., H. antidysentrica, H. indicus, C. equistifolia. T. belerica, T. chebula, E. officinalis, C. sinensis, S. aromaticum and P. granatum). No correlation was observed between susceptibility of test strains with plant extracts and antibiotic resistance behaviour of the microbial strains (Staphylococcus aureus, Salmonella paratyphi, Shigella dysenteriae, Escherichia coli, Bacillus subtilis, Candida albicans). Qualitative phytochemical tests, thin layer chromatography and TLC-bioautography of certain active extracts demonstrated the presence of common phytocompounds in the plant extracts including phenols, tannins and flavonoids as major active constituents.     

An ethnobotanical survey of Bauchi State herbal plants and their antimicrobial activity

A survey of medicinal plants used locally in the treatment of various diseases was carried out in Bauchi State-Nigeria. A total of 84 medicinal plants were listed. Preliminary antimicrobial activity of the aqueous extracts of the plants was investigated. The results indicated that out of 84 plants, 75 exhibited antimicrobial activity against one or more of the test organisms at a concentration of 200 mg/ml. The extracts were found to show potentially interesting activity against Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli.     

Antiviral and antimicrobial activities of Colombian medicinal plants

Strong antiviral and antimicrobial activities were detected in methanolic extracts of 24 plants used medicinally in the treatment of skin infections in four different regions of Colombia. Thirteen extracts displayed activity against herpes simplex virus (HSV) whereas none was active against poliovirus. The antiviral activity was indicated by a total inhibition of viral cytopathic effects (CPE) at a non-cytotoxic concentration of the extract. The most potent extract was obtained from Byrsonima verbascifolia (L.) HBK. which showed anti-HSV activity at a concentration as low as 2.5 microg/ml. Antimicrobial screening was conducted using the disc diffusion assay against Klebsiella pneumoniae, Escherichia coli, Streptococcus faecalis, Mycobacterium phlei, Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium and the human pathogenic yeast, Candida albicans. Anti-Candida activity was observed for Piper lanceaefolium HBK. and Juglans neotropica Diels. Twenty-two extracts displayed activity against Gram-positive bacteria whereas none was active against the Gram-negative species. We concluded that these Colombian medicinal plants represent an untapped source of potentially useful antivirals and are worthy of further study.     

Antimicrobial activities of some selected traditional Ethiopian medicinal plants used in the treatment of skin disorders

Hydroalcoholic extracts of eight species of medicinal plants, namely, Acokanthera schimperi (Apocynaceae), Calpurnia aurea (Leguminosae), Kalanchoe petitiana (Crassulaceae), Lippia adoensis (Verbenaceae), Malva parviflora (Malvaceae), Olinia rochetiana (Oliniaceae), Phytolacca dodecandra (Phytolaccaceae) and Verbascum sinaiticum (Scrophulariaceae), traditionally used in the treatment of various skin disorders were screened for antimicrobial activity against different strains of bacteria and fungi which are known to cause different types of skin infections. The tests were carried out using agar well diffusion method at three concentration levels (100, 50 and 25mg/ml) of the crude extracts. The MICs of the crude extracts of Lippia adoensis and Olinia rochetiana were determined by agar dilution method. Furthermore, the powdered leaves of Lippia adoensis and Olinia rochetiana were fractionated into different solvents of wide ranging polarity and the resulting fractions were screened for antimicrobial activity against the same organisms. Of all the plants tested, Lippia adoensis and Olinia rochetiana were found to be the most active species against bacterial and fungal strains, respectively. In addition, almost all species of plants were found to have activity on at least one microbial strain. The antimicrobial activity profile also showed that Staphylococcus aureus and Trichophyton mentagrophytes were the most susceptible bacterial and fungal strains, respectively. The results indicate the potential of these herbal drugs in treating microbial infections of the skin, thus, justifying their claimed uses in the treatment of various skin disorders, the majority of which are of infectious origin.     

Antimicrobial evaluation of some medicinal plants for their anti-enteric potential against multi-drug resistant Salmonella typhi

Screening was done of some plants of importance in the Ayurvedic system of traditional medicine used in India to treat enteric diseases. Fifty four plant extracts (methanol and aqueous) were assayed for their activity against multi-drug resistant Salmonella typhi. Strong antibacterial activity was shown by the methanol extracts of Aegle marmelos, Salmalia malabarica, Punica granatum, Myristica fragrans, Holarrhena antidysenterica, Terminalia arjuna and Triphal (mixture of Emblica of fi cinalis, Terminalia chebula and Terminalia belerica). Moderate antimicrobial activity was shown by Picorhiza kurroa, Acacia catechu, Acacia nilotica, Cichorium intybus, Embelia ribes, Solanum nigrum, Carum copticum, Apium graveolens, Ocimum sanctum, Peucedanum graveolens and Butea monosperma.     

Screening of some Siberian medicinal plants for antimicrobial activity

The antimicrobial activity of crude ethanolic extracts of 16 Siberian medicinal plants was tested against five species of microorganisms: Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Of the 16 plants tested, 12 showed antimicrobial activity against one or more species of microorganisms. The most active antimicrobial plants were Bergenia crassifolia, Chelidonium majus, Rhaponticum carthamoides, Sanguisorba officinalis, and Tussilago farfara.     

Screening of selected indigenous plants of Lebanon for antimicrobial activity

The objective of this study is to test in vitro the antimicrobial efficacy of 39 water and 39 methanol extracts derived from different parts of 27 indigenous wild plant species that have been commonly used in Lebanese folk medicine. The antimicrobial efficacy was determined using the single disk diffusion method, with 10 and 20 microl load extract volume per disc. Nine test microorganisms were used namely, Escherichia coli, Proteus sp., Pseudomonas aeruginosa, Shigella dysenteria, Salmonella enteritidis, Salmonella typhi, Staphylococcus aureus, Streptococcus faecalis, and Candida albicans. Only one water extract out of 39 derived from whole plant of Alchemilla diademata showed an antimicrobial activity against Staphylococcus aureus. The percentage of test organisms that were susceptible to 10 most efficacious methanol plant extracts (20 microl/disc) were as follows: Achillea damascena whole plant (88.8%), Anthemis scariosa flower (88.8%), Cirsium sp. whole plant (88.8%), Centaurea ainetensis flowers (88.8%), Hieracium sp. whole plant (88.8%), Origanum libanoticum whole plant (99.9%), Ranunculus myosuroudes whole plant (88.8%), Nepata curviflora leaf (88.8%), Nepata curviflora stem, and Verbascum leptostychum flower (99.9%). The minimum inhibitory concentration (MIC) was determined on plant extracts that showed high efficacy against the test organisms. The chance to find antimicrobial activities was more apparent in methanol rather than water extracts of the same indigenous plants of Lebanon, with higher antimicrobial activities in 20 microl methanol extract-discs in comparison to that present in the 10 microl discs (P < 0.05).     

Antibacterial activity of plants used in traditional medicines of Ghana with particular reference to MRSA

ETHNOPHARMACOLOGICAL RELEVANCE: : In an ethno botanical survey carried out in the Akwapim-North district of the Republic of Ghana, 25 plant species, used in traditional medicine to treat skin disease and/or to treat antimicrobial (viral, bacterial or protozoan) infections were identified. AIM OF STUDY: : To investigate the antimicrobial activity of traditional Ghanaian medicines with special interest in anti-methicillin-resistant Staphylococcus aureus (MRSA) activity. MATERIALS AND METHODS: : Chloroform, ethanol and aqueous extracts (including use of a Stomacher) of these plants were prepared and agar-well diffusion tests, MIC's and MBC's were used to investigate antimicrobial activity. RESULTS: Extracts of 13 plant species inhibited the growth of one or more of the following bacteria: MRSA, methicillin-sensitive Staphylococcus aureus (MSSA), Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris. Extracts from 11 of these 13 plant species also inhibited the growth of three or more of 14 additional clinical isolates of MRSA. Aqueous extracts of Alchornea cordifolia were active against all 21 bacterial strains tested and showed the highest levels of antibacterial activity overall with MIC's against MRSA in the range of 1.6-3.1 mgml(-1) and MBC's in the range of 6.3-12.5 mgml(-1). CONCLUSIONS: : The presence of antibacterial activity in extracts of Elaeophorbia drupifera, Rauwolfia vomitoria and the leaves of Solanum verbascifolium, plants traditionally used to treat skin infections, are reported for the first time. Extracts from Alchornea cordifolia, also used to treat wounds, had the widest spectrum of antibacterial activity.     

In vitro cytotoxic activity of some Korean medicinal plants on human cancer cell lines: enhancement in cytotoxicity by heat processing

The goal of this study was to examine the in vitro antiproliferative activity of crude methanol extracts of three traditional Korean medicinal plants: Achyranthes fauriei, Epimedium koreanum Nakai and Scutellaria baicalensis before and after heat processing. The extracts were screened for antitumoral potential by means of an MTT assay on four human cancer cell lines: lung cancer cells (Lu1), colon cancer cells (Col2), oral epidermoid carcinomas (KB) and hormone-dependent prostate cancer cells (LNCaP). None of the extracts showed significant activity against any of the cancer cell lines. However, after treatment with steam, the processed Achyranthes fauriei extract exhibited a slight, but enhanced cytotoxic activity against all four of the cancer cell lines. The processed Scutellaria baicalensis extract exerted a potent cytotoxic activity against the Lu1 cell line in a specific manner with an IC(50) value of 14.3 microg/mL. The Epimedium koreanum extract showed no cytotoxic effects against any of the cancer cell lines with or without heat processing. These results suggest that the heat processing of medicinal plants represents a possible route to the development of antitumor agents.