In vitro anti-plasmodial activity of some traditionally used medicinal plants against Plasmodium falciparum

The anti-plasmodial activity of different solvent extracts of Adhatoda vasica (root), Caesalpinia pulcherrima (leaf), Carica papaya (pulp), Erythroxylum monogynum (leaf), Lantana camara (whole plant), Ocimum sanctum (root) and Phyllanthus niruri (whole plant) were studied against Plasmodium falciparum. Of the 35 extracts tested, seven extracts showed good anti-plasmodial activity. Methanol extract of C. pulcherrima showed the lowest IC50 value (10.96 μg/mL) followed by methanol extract of A. vasica (IC(50)=11.1 μg/mL), chloroform extract of O. sanctum (IC(50)=11.47 μg/mL), methanol extract of E. monogynum (IC(50)=12.23 μg/mL), acetone extract of C. pulcherrima (IC(50)=12.49 μg/mL), methanol extract of O. sanctum and acetone extract of A. vasica (IC(50)=14.04 μg/mL). The results of the present study justify the use of these medicinal plants in traditional practice, and also, a further study on the isolation of anti-plasmodial molecules from their active crude extracts is in progress.     

In vitro antiplasmodial activity of ethanolic extracts of mangrove plants from South East coast of India against chloroquine-sensitive Plasmodium falciparum

Malaria is one of the most prevalent infectious diseases in the world. Treatment for malaria is commonly inadequate due to the lack of quality assured effective drugs. The effectiveness of these drugs is declining at an ever accelerating rate, with consequent increase in malaria related morbidity and mortality. The newest antiplasmodial drug from plants is needed to overcome this problem. Numerous mangroves and mangal associates are used as folklore medicine to treat various human diseases. The mangrove plant species are a good source of potential bioactive entities which exhibits many therapeutic properties. The present study was carried out to test the antiplasmodial activity of five mangrove plant species distributed along the South East coast of India. Bruguiera cylindrica, Ceriops decandra, Lumnitzera racemosa, Rhizophora apiculata, and Rhizophora mucronata mangrove plant extracts exhibited in vitro antiplasmodial activity against chloroquine-sensitive Plasmodium falciparum. Of which, the ethanolic bark extract of R. mucronata exhibited high antiplasmodial activity (IC₅₀ = 62.18 μg.ml⁻¹). Statistical analysis reveals that, significant antiplasmodial activity (P < 0.05) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried out and it shows that no morphological differences in erythrocytes by the ethanolic extract of mangrove plants after 48 h of incubation. The screening for phytochemical constituents in the mangrove plants were carried out and it reveals that, the presence of alkaloids, triterpenes, flavonoids, tannins, catachin, anthroquinone, phenols, sugars, and proteins. This study shows that the mangrove plants had a source of lead compounds for the development of new drugs for the treatment of malaria.     

In vitro sensitivity of Plasmodium falciparum field isolates to extracts from Cameroonian Annonaceae plants

In a search for new plant-derived antimalarial extracts, 19 fractions were obtained from three Annonaceae species, Uvariopsis congolana (leaf, stem), Polyalthia oliveri (stem bark), and Enantia chlorantha (stem, stem bark) with yields ranging from 0.33% to 4.60%. The extracts were prepared from 500 g of each plant part, using organic solvents to afford five methanolic fractions (acetogenin rich), five water fractions, five hexane fractions, and four interface precipitates. Evaluation of the activity of fractions in vitro against field isolates of the malaria parasite Plasmodium falciparum showed that acetogenin-rich fractions and interface precipitates were the most potent, with IC₅₀ values ranging from 0.05 to 8.09 μg/ml. Sensitivity of parasite isolates to plant extracts varied greatly, with over 100-fold difference from isolate to isolate in some cases. The active acetogenin-rich fractions and interface precipitates were assessed in combination with chloroquine in the same conditions, and showed additive interaction in the huge majority of cases. Synergistic interactions were found in some cases with acetogenin-rich fractions. Acute toxicity of promising fractions was evaluated through oral administration in Swiss albino mice. Tested fractions appeared to be safe, with LD₅₀ values higher than 2 g/kg. In summary, acetogenin-rich fractions from Annonaceae species showed high potency against P. falciparum field isolates and safety by oral administration in mice, supporting their detailed investigation for antimalarial drug discovery.     

Antiplasmodial activity of botanical extracts against Plasmodium falciparum

The absence of a vaccine and the rampant resistance to almost all antimalarial drugs have accentuated the urgent need for new antimalarial drugs and drug targets for both prophylaxis and chemotherapy. The aim of the study was to discover effective plant extracts against Plasmodium falciparum. In the present study, the hexane, chloroform, ethyl acetate, acetone, and methanol extracts of Citrus sinensis (peel), Leucas aspera, Ocimum sanctum, Phyllanthus acidus (leaf), Terminalia chebula (seed) were tested for their antimalarial activity against chloroquine (CQ)-sensitive (3D7) strain of P. falciparum which was cultured following the candle-jar method. Antimalarial evaluations of daily replacement of culture medium containing CQ and different plant crude extracts were performed on 96-well plates at 37°C for 24 and 48 h. Parasitemia was determined microscopically on thin-film Giemsa-stained preparations. Plant extracts were tested for their cytotoxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay on human laryngeal cancer cell line (HEp-2) and normal cell line (Vero). Out of the 25 extracts tested, six showed good (IC₅₀ 4.76–22.76 μg/mL), 15 exhibited moderate (IC₅₀ 31.42–88.03 μg/mL), while four displayed mild (IC₅₀ > 100 μg/mL) antiplasmodial activity. The leaf ethyl acetate and methanol extracts of L. aspera; ethyl acetate, acetone, and methanol extracts of P. acidus; and seed acetone extract of T. chebula had good antiplasmodial activity (IC₅₀ = 7.81, 22.76, 9.37, 14.65, 12.68, and 4.76 μg/mL) with selectivity indices 5.43, 2.04, 4.88, 3.35, 3.42, and 9.97 for HEp-2 and >5.79, >2.20, >11.75, >3.41, >3.94, and >7.38 for Vero cells, respectively. These analyses have revealed for the first time that the components present in the solvent extracts of L. aspera, P. acidus, and T. chebula have antiplasmodial activity. The high antiplasmodial activity observed make these plants good candidates for isolation of anti-protozoal compounds which could serve as new lead structures for drug development.     

In vitro antidermatophytic activity and cytotoxicity of extracts derived from medicinal plants and marine algae

Objectives

This study was conducted to evaluate the antidermatophytic activity of 48 extracts obtained from medicinal plants (Cibotium barometz, Melastoma malabathricum, Meuhlenbeckia platyclada, Rhapis excelsa, Syzygium myrtifolium, Vernonia amygdalina) and marine algae (Caulerpa sertularioides, Kappaphycus alvarezii) against Trichophyton rubrum and Trichophyton interdigitale (ATCC reference strains), and the cytotoxicity using African monkey kidney epithelial (Vero) cells. Active plant extracts were screened for the presence of phytochemicals and tested against clinical isolates of Trichophyton tonsurans.

In vitro antimalarial activity of traditionally used Western Ghats plants from India and their interactions with chloroquine against chloroquine-resistant Plasmodium falciparum

Malaria is a major global public health problem, and the alarming spread of drug resistance and limited number of effective drugs now available underline how important it is to discover new antimalarial compounds. An ethnopharmacological investigation was undertaken on Western Ghats plants traditionally used to treat malaria in India; 50 plants were very carefully selected from a total of 372 plants, and 200 extracts were prepared and tested for in vitro antiplasmodial activity alone and in combination with chloroquine (CQ) against CQ-resistant Plasmodium falciparum (strain MRC-Pf-43). In in vitro antiplasmodial activity, when plant extract alone is used, 29 extracts (or 14.5%) showed significant high in vitro antiplasmodial activity with IC₅₀ values ranging from 3.96 to 4.85 μg/ml, 53 extracts (or 26.5%) showed significant good in vitro antiplasmodial activity with IC₅₀ values ranging from 5.02 to 9.87 μg/ml, and 28 extracts (or 14%) showed significant moderate in vitro antiplasmodial activity with IC₅₀ values ranging from 10.87 to 14 μg/ml, respectively. In combination with CQ, 103 extracts (or 51.5%) showed significant synergistic in vitro antiplasmodial activities with synergistic factor values ranging from 1.03 to 1.92, and these activities were up to a fold higher with CQ, suggesting synergistic interactions of the two drugs. Our investigation has confirmed that above 62.1% of the plant extracts showed moderate to high in vitro antiplasmodial activity when used alone, and in combination with CQ, 55.7% of the extracts showed borderline to good synergistic activity.     

In vitro antimalarial activity of medicinal plant extracts against Plasmodium falciparum

Malaria is a major global public health problem, and the alarming spread of drug resistance and limited number of effective drugs now available underline how important it is to discover new antimalarial compounds. In the present study, ten plants were extracted with ethyl acetate and methanol and tested for their antimalarial activity against chloroquine (CQ)-sensitive (3D7) and CQ-resistant (Dd2 and INDO) strains of Plasmodium falciparum in culture using the fluorescence-based SYBR Green assay. Plant extracts showed moderate to good antiparasitic effects. Promising antiplasmodial activity was found in the extracts from two plants, Phyllanthus emblica leaf 50% inhibitory concentration (IC₅₀) 3D7: 7.25 μg/mL (ethyl acetate extract), 3.125 μg/mL (methanol extract), and Syzygium aromaticum flower bud, IC₅₀ 3D7:13 μg/mL, (ethyl acetate extract) and 6.25 μg/mL (methanol extract). Moderate activity (30–75 μg/mL) was found in the ethyl acetate and methanol extracts of Abrus precatorius (seed) and Gloriosa superba (leaf); leaf ethyl acetate extracts of Annona squamosa and flower of Musa paradisiaca. The above mentioned plant extracts were also found to be active against CQ-resistant strains (Dd2 and INDO). Cytotoxicity study with P. emblica leaf and S. aromaticum flower bud, extracts showed good therapeutic indices. These results demonstrate that leaf ethyl acetate and methanol extracts of P. emblica and flower bud extract of S. aromaticum may serve as antimalarial agents even in their crude form. The isolation of compounds from P. emblica and S. aromaticum seems to be of special interest for further antimalarial studies.     

In vitro antimalarial activity of extracts of Albizia gummifera,Aspilia mossambicensis,Melia azedarach and Azadirachta indica against Plasmodium falciparum

Since chemotherapy is presently the primary strategy of malaria control in the world, and some malaria parasites are developing resistance to the commonly used antimalarial drugs, new antimalarial compounds are required. Therefore, it is important to test antimalarial activities of medicinal plant extracts which most herbalists claim to cure malaria. We evaluated the antimalarial activities of extracts of Albizia gummiffera, Aspilia mossambicensis, Melia azedar and Azadirahchta indica against laboratory adapted isolates of Plasmodium falciparum using an in vitro radioisotopic uptake technique. Chloroquine was used as a reference antimalarial drug. Al. gummifera had the highest antimalarial activity (mean fifty percent inhibitory concentration {IC(50)S} in ug/ml of test culture =3.5 +1.6SD, n=3) followed by As. mossambicensis (mean IC(50)=29.3+11.8SD, n=4) and Me. Azedarach (mean IC(50) =299.7+202.0SD, n=4). And lastly Az. Indica (mean IC(50)=349.9+213.1 SD, n=4). The antimalarial activities of the reference drug, chloroquine, was far much higher (mean IC(50)=0.065+0.057SD, n=)4). These findings show that Al. gummifera and As. mossambicensis plant extracts have potent antimalarial compounds. Phytochemical analyses should be done on these two plants to isolate the compound(s) containing he active principles(s).     

In vitro screening of medicinal plant extracts for macrofilaricidal activity

Methanolic extracts of 20 medicinal plants were screened at 1–10 mg/ml for in vitro macrofilaricidal activity by worm motility assay against adult Setaria digitata, the cattle filarial worm. Four plant extracts showed macrofilaricidal activity by worm motility at concentrations below 4 mg/ml and an incubation period of 100 min. Complete inhibition of worm motility and subsequent mortality was observed at 3, 2, 1 and 1 mg/ml, respectively, for Centratherum anthelminticum, Cedrus deodara, Sphaeranthus indicus and Ricinus communis. 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay was carried out at 1 mg ml⁻¹ and 4-h incubation period, and the results showed that C. deodara, R. communis, S. indicus and C. anthelminticum exhibited 86.56, 72.39, 61.20 and 43.15% inhibition respectively in formazan formation compared to the control. This research is supported by The International Foundation for Science (IFS) and Organization for Prohibition of Chemical Weapons (OPWC), Stockholm, Sweden through a Grant to Dr. Nisha Mathew (Grant No. F/2929-1).     

Piperidones with activity against Plasmodium falciparum

The increasing resistance of the malaria parasites has enforced new strategies of finding new drug targets. We have isolated two genes involved in spermidine metabolism, encoding deoxyhypusine synthase (DHS) and eukaryotic initiation factor 5A (eIF-5A) in the malaria parasites. eIF-5A is activated by the formation of the unusual amino acid hypusine. This process occurs in two steps. DHS transfers an aminobutyl moiety from the triamine spermidine to a specific lysine residue in the eIF-5A precursor protein to form deoxyhypusine. In a second step, deoxyhypusine hydroxylase (DHH), completes hypusine biosynthesis. We used DHH inhibitors, being effective in mammalian cells, to study an antiplasmodicidal effect in Plasmodium falciparum. Experiments with the antifungal drug ciclopiroxolamine, an α-hydroxypyridone, and the plant amino acid l-mimosine, a 4-pyridone, resulted in an antiplasmodial effect in vitro. Using mimosine as a lead structure, alkyl 4-oxo-piperidine 3-carboxylates were found to have the most efficient antiplasmodial effects in vitro and in vivo.     

In vitro antioxidant and cytotoxicity activities of selected indigenous South African medicinal plants

BackgroundMedicinal plants are regarded as a large source of phytochemicals that may have anticancer properties. This could lead to the development of innovative drugs or alternative therapy against cancer.ObjectiveThis study was designed to determine the antioxidant and cytotoxicity effect of 5 selected indigenous South African medicinal plants namely; Bulbine frutescens, Bulbine natalensis, Chlorophytum comosum, Kniphofia uvaria, and Tulbaghia violacea.MethodPhytochemical extracts namely; methanol, 50%, 100% ethanol, and water extracts were prepared from the root and shoot of the plants. The antioxidant effect of methanol extracts of the plant materials was performed using a DPPH assay. A preliminary cytotoxicity screening of the phytochemical extracts in the human colon (Caco-2), cervical (HeLa), and hepatocellular (HepG2) cell lines were determined followed by the half-maximal inhibitory concentration (IC50) using MTT assay.ResultThe methanol root extract of B. natalensis and B. frutescens (33.20% and 26.33% respectively) and shoot extract of K. uvaria (17.10%) showed the highest antioxidant. Out of the 5 plants, only 100% ethanol extract of C. comosum, K. uvaria, and T. violacea caused more than 80% cytotoxicity in HepG2 and Caco-2 cell lines. The shoot of B. frutescens (10.43 µg/ml), K. uvaria (23.0 µg/ml), and root of C. comosum (23.77 µg/ml) were the most active with the highest cytotoxicity.ConclusionC. comosum, K. uvaria, and T. violacea possess significant cytotoxicity that is promising in developing alternative drugs against colon and liver cancers. Our results provided new pieces of evidence for antioxidant and cytotoxic activities of these plants which could be useful for developing new anticancer therapies.     

An in vitro evaluation of extracts from some medicinal plants in Kenya against herpes simplex virus

The extracts from 21 medicinal plants commonly used in traditional remedies in Kenya were screened for antiviral activity against wild type 7401H strain herpes simplex virus type 1. The plant extracts exhibited antiviral activity against the virus in the plaque and yield reduction assays. The results reveal that twelve plants may contain constituents that could be exploited for the management of HSV infections. Although the extracts used in these experiments contain a complex matrix of a large number of compounds the results indicate that useful compounds can be isolated for further exploitation.     

In vitro antiplasmodial activity of bacterium RJAUTHB 14 associated with marine sponge Haliclona Grant against Plasmodium falciparum

Malaria is the most important parasitic disease, leading to annual death of about one million people, and the Plasmodium falciparum develops resistance to well-established antimalarial drugs. The newest antiplasmodial drug from a marine microorganism helps in addressing this problem. In the present study, Haliclona Grant were collected and subjected for enumeration and isolation of associated bacteria. The count of bacterial isolates was maximum in November 2007 (18?×?10(4) colony-forming units (CFU)?g(-1), and the average count was maximum during the monsoon season (117?×?10(3) CFU g(-1)). Thirty-three morphologically different bacterial isolates were isolated from Haliclona Grant, and the extracellular ethyl acetate extracts were screened for antiplasmodial activity against P. falciparum. The antiplasmodial activity of bacterium RJAUTHB 14 (11.98 μg[Symbol: see text]ml(-1)) is highly comparable with the positive control chloroquine (IC(50) 19.59 μg[Symbol: see text]ml(-1)), but the other 21 bacterial extracts showed an IC(50) value of more than 100 μg[Symbol: see text]ml(-1). Statistical analysis reveals that significant in vitro antiplasmodial activity (P?相似文献   

In vitro antiplasmodial activity of some medicinal plants of Burkina Faso

Malaria remains a major public health problem due to the emergence and spread of Plasmodium falciparum drug resistance. There is an urgent need to investigate new sources of antimalarial drugs which are more effective against Plasmodium falciparum. One of the potential sources of antimalarial drugs is traditional medicinal plants. In this work, we studied the in vitro antiplasmodial activity of chloromethylenic, methanolic, and MeOH/H₂O (1/1) crude extracts and decoction obtained from eight medicinal plants collected in Burkina Faso and of total alkaloids for five plants. Extracts were evaluated in vitro for efficacy against Plasmodium falciparum strain K1, which is resistant to chloroquine, pyrimethamine and proguanil using the fluorescence-based SYBR Green I assay. The antiproliferative activity on human-derived hepatoma cell line HepG2 and Chinese hamster ovary (CHO) cells was evaluated using the 3-[4,5-dimethylthyazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test in order to determine the selectivity index. Among the plant extracts tested for in vitro antiplasmodial activity, 16 were considered to be inactive (with IC₅₀?>?10 μg/ml), six showed a moderate activity (5?<?IC₅₀?≤?10 μg/ml), and six were found to have a good in vitro activity with IC₅₀ value?≤?5 μg/ml. The highest antiplasmodial activity was found for extracts from: the alkaloid leaf extract and the chloromethylenic extracts of Combretum fragrans (IC₅₀?=?3 μg/ml, IC₅₀?=?5 μg/ml), the total alkaloids and the chloromethylenic leaf extracts of Combretum collinum (IC₅₀?=?4 μg/ml), the MeOH/H₂O leaf extract of Terminalia avicennioides (IC₅₀?=?3.5 μg/ml), and the alkaloid leaf extract of Pavetta crassipes (IC₅₀?=?5 μg/ml). Three other extracts showed moderate antiplasmodial activity (5?<?IC₅₀?≤?10 μg/ml): Terminalia avicennioides and Combretum fragrans methanolic extracts and Acacia kirkii alkaloid leaf extract (IC₅₀?=?6.5, 9 and 10 μg/ml respectively). The Terminalia avicennioides crude MeOH/H₂O (80:20 v/v) extract of the leaves was submitted to a successive liquid/liquid extraction with ethylacetate and n-butanol respectively. The extracts were investigated for in vitro antiplasmodial activity and antioxidant properties using DPPH^●, ABTS⁺ and FRAP methods. The ethylacetate extract showed the best antiplasmodial activity (7 μg/ml) and the active constituent was isolated as ellagic acid by bioguided fractionation with an IC₅₀?=?0.2 μM on Plasmodium falciparum and SI?=?152. Besides, Terminalia avicennioides leaf extract and ellagic acid showed a good antioxidant activity. Our finding confirms the importance of investigating the antimalarial activity of plant species used in traditional medicine. Overall, two plants belonging to the Combretaceae family, Combretum fragrans and Combretum collinum appeared to be the best candidates and will be further investigated for their antiplasmodial properties, in order to isolate the molecules responsible for the antiplasmodial activity.     

Crude extracts activity of three selected medicinal plants from the Venda region against some pathogenic organisms

BackgroundThe emerging of antimicrobial resistance has become a problem as it is threatening public health worldwide.ObjectivesTo extract crude extracts from three different medicinal plants, test activity against Mycobacterium smegmatis, Staphylococcus aureus and Escherichia coli and screen for phytochemicals of those that showed activity against the targeted bacteria.MethodsKirkiaacuminataOliv., Dichrostachyscinerea (L.) Wight &Arn. and MimusopszeyheriSond. plants were collected at Thengwe area, Mafukani village, Limpopo Province, South Africa. The plant materials collected were extracted using four solvents. Antimicrobial screening was accomplished using the agar well diffusion method and the crude extracts that showed activity against the targeted organisms were screened for phytochemicals using different tests.ResultsWith all solvents used for extraction, methanol had a greater yield of 14.1% from Dichrostachyscinerea crude extracts. Kirkiaacuminata and Dichrostachyscinerea were medicinal plants that inhibited Mycobacterium smegmatis and Staphylococcus aureus at the lowest concentration of 2.5 mg/ml and 1.25 mg/ml.ConclusionsThe results from this study show that the selected medicinal plants are active against Mycobacterium smegmatis and Staphylococcus aureus and their pharmacological properties can be further analyzed for the development of new drugs.     

Bioassay-guided isolation and characterization of active antiplasmodial compounds from Murraya koenigii extracts against Plasmodium falciparum and Plasmodium berghei

Malaria is an overwhelming impact in the poorest countries in the world due to their prevalence, virulence and drug resistance ability. Currently, there is inadequate armoury of drugs for the treatment of malaria. This underscores the continuing need for the discovery and development of new effective and safe antimalarial drugs. To evaluate the in vitro and in vivo antimalarial activity of the leaf ethyl acetate extract of Murraya koenigii, bioassay-guided chromatographic fractionation was employed for the isolation and purification of antimalarial compounds. The in vitro antimalarial activity was assayed by the erythrocytic stages of chloroquine-sensitive strain of Plasmodium falciparum (3D7) in culture using the fluorescence-based SYBR Green I assay. The in vivo assay was done by administering mice infected with Plasmodium berghei (NK65) four consecutive daily doses of the extracts through oral route following Peter’s 4-day curative standard test. The percentage suppression of parasitaemia was calculated for each dose level by comparing the parasitaemia in untreated control with those of treated mice. Cytotoxicity was determined against HeLa cells using MTT assay. Histopathology was studied in kidney, liver and spleen of isolated compound-treated Swiss albino mice. The leaf crude ethyl acetate extract of M. koenigii showed good in vitro antiplasmodial activity against P. falciparum. The in vivo test of the leaf crude ethyl acetate extract (600 mg/kg) showed reduced malaria parasitaemia by 86.6 % against P. berghei in mice. Bioassay-guided fractionation of the leaf ethyl acetate extract of M. koenigii led to the isolation of two purified fractions C3B2 (2.84 g) and C3B4 (1.97 g). The purified fractions C3B2 and C3B4 were found to be active with IC₅₀ values of 10.5?±?0.8 and 8.25?±?0.2 μg/mL against P. falciparum, and in vivo activity significantly reduced parasitaemia by 82.6 and 88.2 % at 100 mg/kg/body weight on day 4 against P. berghei, respectively. The isolated fractions C3B2 and C3B4 were monitored by thin-layer chromatography until a single spot was obtained with R _f values of 0.36 and 0.52, respectively. The pure compounds obtained in the present investigation were subjected to UV–visible spectroscopy, Fourier transformer infrared spectroscopy, 1D and 2D ¹H-Nuclear magnetic resonance (NMR), ¹³C NMR, DEPT, COSY and Mass spectral analysis. Based on the spectral analysis, it is concluded that the isolated compounds were myristic acid (C3B2) and β-caryophyllene (C3B4). The cytotoxic effect of myristic acid and β-caryophyllene showed the TC₅₀ values of >100 and 80.5 μg/mL, respectively against HeLa cell line. The histopathology study showed that protection against nephrotoxicity of kidney, hepatic damage of liver and splenocytes protection in spleen was achieved with the highest dose tested at 100 mg/kg/body weight. The present study provides evidence of antiplasmodial compounds from M. koenigii and is reported for the first time.     

Antimicrobial activity of selected South African medicinal plants

ABSTRACT: BACKGROUND: Nearly 3,000 plant species are used as medicines in South Africa, with approximately 350 species forming the most commonly traded and used medicinal plants. In the present study, twelve South African medicinal plants were selected and tested for their antimicrobial activities against eight microbial species belonging to fungi, Mycobacteria, Gram-positive and Gram-negative bacteria. METHODS: The radiometric respiratory technique using the BACTEC 460 system was used for susceptibility testing against Mycobacterium tuberculosis, and the liquid micro-broth dilution was used for other antimicrobial assays. RESULTS: The results of the minimal inhibitory concentration (MIC) determinations indicated that the methanol extracts from Acacia karoo, Erythrophleum lasianthum and Salvia africana were able to prevent the growth of all the tested microorganisms. All other samples showed selective activities. MIC values below 100μg/ml were recorded with A. karoo, C. dentate, E. lasianthum, P. obligun and S. africana on at least one of the nine tested microorganisms. The best activity (MIC value of 39.06μg/ml) was noted with S. africana against E. coli, S. aureus and M. audouinii, and Knowltonia vesitoria against M. tuberculosis. CONCLUSION: The overall results of the present work provide baseline information for the possible use of the studied South African plant extracts in the treatment of microbial infections.     

In vitro activity of tigecycline against strains isolated from diabetic foot ulcers

Purpose of the studyThe aim of this study was to evaluate the in vitro activity of tigecycline and other comparator agents against bacterial strains isolated from diabetic foot infections (DFI).Patients and methodsAll diabetic patients hospitalized for a first episode of DFI (stage 2 to 4, according to the International Working Group of Diabetic Foot classification) were selected in Nîmes University hospital between January 2005 and June 2006. MICs were determined using custom broth microdilution panels against bacterial strains isolated from foot samples.ResultsThree hundred fifteen strains were studied. Tigecycline was active against 83.7% of all the strains especially Gram-positive cocci (97.3%) in particular methicillin-resistant Staphylococcus aureus (96%), Enterobacteriaceae (88.5%) and anaerobes (100%). Exclusively Pseudomonas aeruginosa and Proteae were not covered by this antibiotic.ConclusionsTigecycline, a new broad spectrum antimicrobial agent, is qualified to belong to the therapeutic arsenal package of complicated skin and soft tissue infections in diabetic patients after microbial documentation.     

BACE1 inhibitory activity of fungal endophytic extracts from Malaysian medicinal plants

Background

The roots of Sophora flavescens (Leguminosae) have been used in East Asian countries as an herbal medicine and a food ingredient for thousands of years. The aim of the present study was to investigate the effects of S. flavescens fermentation on endotoxin-induced uveitis (EIU) in rats.

Methods

EIU was induced in rats via a footpad injection of lipopolysaccharide (LPS). Immediately after the LPS inoculation, fermented and non-fermented extracts of S. flavescens (FSE and NFSE, respectively) were administered orally, and the aqueous humor was collected from both eyes 24 hours later. The anti-inflammatory effects of FSE and NFSE were examined in terms of regulation of nuclear factor kappa B (NF-κB) activation and the expression of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), intercellular cell adhesion molecule (ICAM)-1, and cyclooxygenase-2 (COX-2). The regulation of maleic dialdehyde (MDA) levels and polymorphonuclear cell (PMN) infiltration by FSE and NFSE were also examined.

Results

Treatment with FSE significantly inhibited LPS-induced increases in IL-1β and TNF-α production and the expression of iNOS, ICAM-1 and COX-2. Moreover, FSE suppressed LPS-induced NF-κB activation, and reduced both MDA levels and infiltration by PMN.

Conclusion

These results indicate that solid state fermentation may enhance the anti-inflammatory effects of S. flavescens.