Evaluation of antioxidant and antimicrobial properties of Soymida febrifuga leaf extracts

The present study was designed to evaluate the antioxidant and antimicrobial properties of hexane (LH), methanol (LM) and aqueous (LA) extracts of Soymida febrifuga (Maliaceae) leaves, which is a traditional folk medicine in India. No pharmacological evaluation of this plant (except antiplasmodial activity) has been reported to date. Antioxidant activity of different extracts was evaluated by DPPH free radical scavenging activity, taking total phenolic content (TPC) as an index. Antimicrobial activity was tested against six bacterial and five fungal strains using the agar hole diffusion method and the minimum inhibitory concentrations (MIC) and minimum microbicidal concentration (MMC) were determined for all the test organisms against the extracts. The results showed that the methanol and aqueous extracts of leaf had a higher antioxidant activity and total phenolic content than the hexane extract. The antioxidant activity and TPC of the extracts were highly correlated. Extracts also showed several degrees of antimicrobial activity against different microbes. The methanol extract was more potent against Aspergillus fumigatus and Candida tropicana. The lowest MIC values obtained for LM, LA and LH were 78, 156, 625 microg/mL against A. fumigatus, C. tropicana and C. albicans, respectively. Hence, this study confirms that Soymida febrifuga leaves possess potent antioxidant and antimicrobial activity.     

Effects of Mikania genus plants on growth and cell adherence of mutans streptococci

The present study evaluated the chemical composition and the antimicrobial activity of the extracts and fractions of Mikania laevigata and Mikania glomerata on growth and cell adherence of mutans streptococci. Ethanolic extract, hexane and ethyl acetate fractions of Mikania laevigata and Mikania glomerata were chemically identified by chromatographic methods and tested on mutans streptococci from culture collection and clinical isolates. Twenty-two compounds were identified in both Mikania extracts, including coumarin, 1-octadecene, and diterpenic, cupressenic and kaurenoic acids. Antimicrobial activity was assessed by determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and inhibition of cell adherence to a glass surface. Hexane fraction from both plant extracts was the most effective in inhibiting the growth of the bacterial strains tested (MIC values between 12.5 microg/ml and 400 microg/ml, and MBC values between 25 microg/ml and 400 microg/ml). In addition, sub-MIC levels of the crude extracts and their hexane fractions significantly inhibited the adherence of the microorganisms to a glass surface. The data indicate that the biologically active compounds are present mostly in the hexane fraction of both Mikania species, which showed remarkable inhibitory activities against mutans streptococci. Mikania genus plant is a promising source for novel antimicrobial agents against oral pathogens.     

Antimicrobial studies on three species of Hypericum from the Canary Islands

The antimicrobial activity of several extracts and fractions of the aerial parts of Hypericum canariense, Hypericum glandulosum and Hypericum grandifolium was investigated using the disc diffusion and broth microdilution methods against twelve reference microorganisms (eight bacterial and four fungal strains). The methanol extract and chloroform fraction of H. canariense, as well as the methanol extracts, butanol and chloroform fractions of both H. glandulosum and H. grandifolium exhibited a good antibacterial activity against four Gram-positive bacteria (Bacillus cereus var. mycoides, Micrococcus luteus, Staphylococcus aureus and Staphylococcus epidermidis) and the Gram-negative bacterium Bordetella bronchiseptica with the diameters of growth inhibition area in the range 10-25 mm and MICs values between 0.03 and 0.29 mg/ml. Neither the infusions and aqueous fractions of the species studied nor the butanol fraction of H. canariense showed any antibacterial activity against the tested microorganisms. Amongst the active extracts, the minimum inhibitory concentration (MIC) determination showed that the H. canariense chloroform fraction was the most active against M. luteus, S. aureus and S. epidermidis. No antifungal activity was seen with any of the extracts or fractions tested. The results of this study support the use of these species in Canarian traditional medicine to treat skin infections.     

Evaluation of antimicrobial activities of Satureja hortensis L

The present study was designated to evaluate the antimicrobial activities of methonol and hexane extracts of Satureja hortensis L. which is an annual herb used as traditional folk medicine in Eastern Anatolia region of Turkey for the treatment of different infectious diseases and disorders. The antimicrobial activities of the extracts against 147 laboratory strains belong to 55 bacterial species, and 31 isolates of 1 yeast and 4 fungi species were tested by using disc diffusion assay. The results showed that hexane extract of Satureja hortensis had no antifungal, but antibacterial activity against four strains of three Bacillus species whereas methanol extract of Satureja hortensis had both anticandidal and antibacterial effects. It inhibited the growth of 23 strains of 11 bacterial species and 6 isolates of Candida albicans, at the concentration of 300microg/ml. Satureja hortensis did not show antimicrobial activity against the remaining microorganisms (83%) tested including most and all of the clinic and plant pathogenic microorganisms, respectively. Methanol extract showed stronger and broader spectrum of antimicrobial activity as compared to hexane extract.     

Antifungal activities of six South African Terminalia species (Combretaceae)

A serial microplate dilution method developed for bacteria was modified slightly and gave good results with several fungi. The antifungal activity of acetone, hexane, dichloromethane and methanol leaf extracts of six Terminalia species (Terminalia prunioides, Terminalia brachystemma, Terminalia sericea, Terminalia gazensis, Terminalia mollis and Terminalia sambesiaca) were tested against five fungal animal pathogens (Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, Microsporum canis and Sporothrix schenkii). Methanol extracted the highest quantity, but the acetone extracts had the highest antifungal activity. Some of the extracts had antioxidant activity. Most of the antifungal extracts had MIC values of c. 0.08 mg/ml, some were with MIC values as low as 0.02 mg/ml. Microsporum canis was the most susceptible microorganism and Terminalia sericea extracts were the most active against nearly all microorganisms tested.     

Antimicrobial activity of plants used in traditional medicine of San Juan province, Argentine

Eighteen extracts from Acaena magellanica, Baccharis grisebachii, Ephedra breana, Oxalis erythrorhiza, Pachylaena atriplicifolia and Satureja parvifolia were assessed for antimicrobial activity against bacteria and fungi with the agar dilution method. The hexane (H) and dichloromethane (DCM) extracts of B. grisebachii and O. erythrorhiza showed the broadest spectrum of action against fungi, inhibiting all of the tested dermatophytes with MICs ranging from < or =25 to < or =1000 microg/ml. Trichophyton rubrum was the most susceptible species and Cryptococcus neoformans was inhibited only by the DCM extract of B. grisebachii with MIC of 600 microg/ml. Regarding the antibacterial activity, H and DCM extracts of B. grisebachii as well as the DCM of O. erythrorhiza, were active on methicillin-resistant and methicillin-sensitive Staphylococcus aureus with MIC from < or =125 to < or =500 microg/ml. The DCM extract of B. grisebacchii was more active against methicillin-resistant than methicillin-sensitive strains.     

Antimicrobial activity and cytotoxicity of the essential oil of Curcuma zedoaria

The chemical compositions of the essential oil of Curcuma zedoaria (Berg.) Rosc. were analyzed by gas chromatography-mass spectrometry (GC-MS) and showed a high content of epicurzerenone and curdione representing 46.6% and 13.7% of the total oil, respectively. The essential oil was evaluated for potential antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonasa aeruginosa, Vibrio parahaemolyticus, Salmonella typhimurium and Bacillus cereus. V. parahaemolyticus was sensitive to the presence of the essential oil, while the most resistant strain appeared to be E. coli. Based on 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay, nitroblue tetrazolium (NBT) reduction and cell morphology, the essential oil of C. zedoaria could inhibit the proliferation of human promyelocytic leukemia HL-60 cells. These results suggest that the essential oil has the antimicrobial activity against some of Gram- positive and negative pathogenic microorganisms and the components of the extract lead to the apoptosis of human cancer cell line.     

Phytochemical and antimicrobial studies of Begonia malabarica.

Phytochemical investigation of the various extracts of the leaves of Begonia malabarica Lam. (Begoniaceae) resulted in the isolation and identification of six known compounds, viz. friedelin, epi-friedelinol, beta-sitosterol, luteolin, quercetin and beta-sitosterol-3-beta-D-glucopyranoside. The aqueous and organic solvent extracts were also tested against ten human pathogenic bacteria and four fungal strains by the agar-well diffusion method. All the extracts were devoid of antifungal activity against the tested fungi. The hexane extract did not show any activity. The aqueous extracts showed activity against the Gram-negative bacteria except Vibrio parahaemolyticus. The chloroform and methanol extracts showed activity against all the tested bacteria. The study supported the claim of the usefulness of the plant in respiratory tract infections and also suggests its use in diarrhoea and skin diseases caused by pathogenic bacteria.     

Evaluation of natural products on inhibition of inducible cyclooxygenase (COX-2) and nitric oxide synthase (iNOS) in cultured mouse macrophage cells

The inhibitors of prostaglandin biosynthesis and nitric oxide production have been considered as potential anti-inflammatory and cancer chemopreventive agents. In this study, we evaluated approximately 170 methanol extracts of natural products including Korean herbal medicines for the inhibition of prostaglandin E(2) production (for COX-2 inhibitors) and nitric oxide formation (for iNOS inhibitors) in lipopolysaccharide (LPS)-induced mouse macrophages RAW264.7 cells. As a result, several extracts such as Aristolochia debilis, Cinnamomum cassia, Cinnamomum loureirii, Curcuma zedoaria, Eugenia caryophyllata, Pterocarpus santalius, Rehmania glutinosa and Tribulus terrestris showed potent inhibition of COX-2 activity (>80% inhibition at the test concentration of 10 micro g/ml). In addition, the extracts of A. debilis, Caesalpinia sappan, Curcuma longa, C. zedoaria, Daphne genkwa and Morus alba were also considered as potential inhibitors of iNOS activity (>70% inhibition at the test concentration of 10 micro g/ml). These active extracts mediating COX-2 and iNOS inhibitory activities are warranted for further elucidation of active principles for development of new cancer chemopreventive and/or anti-inflammatory agents.     

60味中药提取物抗菌活性的研究

目的:体外观察60味中药的240种提取物对9种常见病原菌的作用,并对其中抑菌效果明显的提取物进行最低抑菌浓度检测。方法:采用纸片扩散法对240种提取物进行初步的抗菌活性筛选,并采用液体培养基法(2倍稀释法)测定活性提取物的最低抑菌浓度(MIC)。结果:共有104种提取物对1种或多种细菌显示较强的抑制作用,其中丹参等11味中药的20种提取物对3种常见菌体现了强抑制作用(MIC<0.2 mg·mL-1)。结论:丹参、蛇床子、蓼蓝、蒲公英、桑叶、甘草、姜黄、紫草、半边莲、野菊花和密蒙花等11味中药的乙醇、丙酮、正己烷提取部位对枯草芽孢杆菌、蜡样芽孢杆菌和金黄色葡萄球菌有强抑制作用。     

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 activity of the essential oil and extracts of Cordia curassavica (Boraginaceae)

In traditional Mexican medicine Cordia curassavica (Jacq) Roemer & Schultes is used to treat gastrointestinal, respiratory and dermatological disorders in Zapotitlán de las Salinas, Puebla (México). The aim of this work was to investigate antimicrobial activity of the essential oil, obtained by using Clevenger distillation apparatus, and hexane, chloroform and methanol extracts from aerial parts of Cordia curassavica. Antimicrobial activity was evaluated against 13 bacteria and five fungal strains. The oil and extracts exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria and five fungal strains. Sarcina lutea and Vibrio cholerae were the strains more sensitive to the essential oil effect (MIC=62 microg/mL) and Vibrio cholerae for the hexane extract (MIC=125 microg/mL). Rhyzoctonia solani was the strain more sensitive to the essential oil effect (IC(50)=180 microg/mL) and Trichophyton mentagrophytes for the hexane extract (IC(50)=230 microg/mL). The essential oil was examined by GC and GC-MS. A total 11 constituents representing 96.28% of the essential oil were identified: 4-methyl,4-ethenyl-3-(1-methyl ethenyl)-1-(1-methyl methanol)cyclohexane (37.34%), beta-eudesmol (19.21%), spathulenol (11.25%) and cadina 4(5), 10(14) diene (7.93%) were found to be the major components. The present study tends to confirm the use in the folk medicine of Cordia curassavica in gastrointestinal, respiratory and dermatological diseases.     

Screening of anti-bacterial activity of medicinal plants from Belize (Central America)

Twenty-one extracts from seven herbal drugs, Aristolochia trilobata (Aristolochiaceae) leaves and bark, Bursera simaruba (Burseraceae) bark, Guazuma ulmifolia (Sterculiaceae) bark, Hamelia patens (Rubiaceae) leaves and Syngonium podophyllum (Araceae) leaves and bark, used in traditional medicine of Belize (Central America) as deep and superficial wound healers, were evaluated for their anti-bacterial properties. Activity was tested against standard strains of Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212. Almost all the extracts were able to inhibit the growth of one or more of the bacterial strains, except that of Enterococcus faecalis. For the first time an anti-microbial activity is reported for Aristolochia trilobata as well as for Syngonium podophyllum. The hexane extracts of Aristolochia trilobata leaves and bark were the most active extracts against Staphylococcus aureus (MIC=0.31 and 0.625mg/ml, respectively).     

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.     

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.     

羊耳菊水提取物体外抑菌活性研究

目的 探讨羊耳菊不同器官水提取物的体外抑菌活性.方法 以金黄色葡萄球菌、铜绿假单胞菌、白色念珠菌等10种微生物为试验菌株,采用药敏纸片扩散法、试管二倍稀释法,对羊耳菊水提取物进行抑菌试验.结果 羊耳菊全株各器官都具有较强的抑菌作用,其中根对10种供试菌种都有抑制作用,抑制范围最广;茎对9种供试菌种有抑制作用,叶对8种供试菌种有抑制作用.羊耳菊各器官对金黄色葡萄球菌与铜绿假单胞菌的抑制作用最强.羊耳菊根、茎、叶对金黄色葡萄球菌的MIC值分别为15.63,62.5,62.5 mg/ml,而其抑菌圈直径分别为14.3,13.8,13.5 mm;羊耳菊根,茎,叶对铜绿假单胞菌的MIC值分别为15.63,31.25,62.5 mg/ml,其抑菌圈直径分别为15.8,15.5,14.0 mm.结论 羊耳菊水提取物体外试验证实了该民间药物具有抗菌活性,也表明了羊耳菊是一种有开发潜力的新抗菌药物资源.     

Antimicrobial activity of the methanolic extracts and compounds from Vismia laurentii De Wild (Guttiferae)

Methanolic extracts prepared from the leaves, twigs and the roots of Vismia laurentii De Wild as well as nine compounds isolated from these crude extracts, were tested for their antimicrobial activity against Gram-positive bacteria (six species), Gram-negative bacteria (12 species) and two Candida species using disc diffusion and well micro-dilution methods. The disc diffusion assay indicated that the crude extract was active against all the pathogens tested, whereas isolated compounds showed selective activities. The degree of sensitivity of the test organisms to purified compounds varied from 25 to 90%. Fridelin (8) was found to be the most active compound, while Bivismiaquinone (3) was the least active. The lowest minimum inhibition concentration (MIC) values as obtained by the micro-dilution assays were 19.53 and 1.22 microg/ml for the crude extracts and purified compounds, respectively. The lowest value for the purified compounds (1.22 microg/ml) was obtained with O(1)-demethyl-3',4'-deoxypsorospermin-3',4'-diol (6) on Candida gabrata and Bacillus subtilis; 1,8-dihydroxy-6-methoxy-3-methylanthraquinone (5) on Bacillus subtilis and 6-deoxyisojacareubin (7) on Bacillus stearothermophilus. These results provide promising baseline information for the potential use of these crude extracts as well as some of the isolated compounds in the treatment of bacterial and fungal infections.     

Antimicrobial activity of aqueous and methanol extracts of Juniperus oxycedrus L

Aqueous and methanol extracts of the leaves of Juniperus oxycedrus were investigated for their in vitro antimicrobial properties. The plant was collected from Pelitli Village of Gebze, Kocaeli, in the Marmara region of Turkey. Juniperus oxycedrus is widely used as traditional folk medicine in Turkey for treatment of different infectious diseases. The antimicrobial activity of the extracts against 143 laboratory strains belonging to 56 bacterial species, and 31 isolates of 5 fungi species were evaluated based on the inhibition zone using the disc-diffusion assay, minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC) values. The aqueous extract of J. oxycedrus had no antimicrobial effect against the test microorganisms whereas the methanol extract had inhibitory effects on the growth of 57 strains of 24 bacterial species in the genera of Acinetobacter, Bacillus, Brevundimonas, Brucella, Enterobacter, Escherichia, Micrococcus, Pseudomonas, Staphylococcus, and Xanthomonas. In addition 11 Candida albicans isolates at a concentration of 31.25-250 micro g/ml were also inhibited.     

Antimicrobial activity of the crude extracts and five flavonoids from the twigs of Dorstenia barteri (Moraceae)

The aim of this study was to evaluate the antimicrobial activity of the crude extract of the twigs of Dorstenia barteri (DBT) as well as that of four of the five flavonoids isolated from this extract. Gram-positive bacteria (six species), Gram-negative bacteria (12 species) and fungi (four species) were used. The agar disc diffusion test was used to determine the sensitivity of the tested samples while the well micro-dilution was used to determine the minimal inhibition concentrations (MIC) and the minimal microbicidal concentration (MMC) of the active samples. The results of the disc diffusion assay showed that DBT, isobavachalcone (1), and kanzonol C (4) prevented the growth of all the 22 tested microbial species. Other compounds showed selective activity. The inhibitory activity of the most active compounds namely compounds 1 and 4 was noted on 86.4% of the tested microorganisms and that of 4-hydroxylonchocarpin (3) was observed on 72.7%. This lowest MIC value of 19.06microg/ml was observed with the crude extract on seven microorganisms namely Citrobacter freundii, Enterobacter aerogens, Proteus mirabilis, Proteus vulgaris, Bacillus megaterium, Bacillus stearothermophilus and Candida albicans. For the tested compounds, the lowest MIC value of 0.3microg/ml (on six of the 22 organisms tested) was obtained only with compound 1, which appeared as the most active compound. This lowest MIC value (0.3microg/ml) is about 4-fold lower than that of the RA, indicating the powerful and very interesting antimicrobial potential of isobavachalcone (1). The antimicrobial activities of DBT, as well as that of compounds 1, 3, 4, amentoflavone (5) are being reported for the first time. The overall results provide promising baseline information for the potential use of the crude extracts from DBT as well as some of the isolated compounds in the treatment of bacterial and fungal infections.