In vitro susceptibility of Helicobacter pylori to isoquinoline alkaloids from Sanguinaria canadensis and Hydrastis canadensis

Methanol extracts of the rhizomes of Sanguinaria canadensis, and the roots and rhizomes of Hydrastis canadensis, two plants used traditionally for the treatment of gastrointestinal ailments, were screened for in vitro antibacterial activity against 15 strains of Helicobacter pylori. The rhizome extracts, as well as a methanol extract of S. canadensis suspension-cell cultures inhibited the growth of H. pylori in vitro, with a MIC50 range of 12.5-50.0 microg/ml. Three isoquinoline alkaloids were identified in the active fraction. Sanguinarine and chelerythrine, two benzophenanthridine alkaloids, inhibited the growth of the bacterium, with an MIC50 of 50.0 and 100.0 microg/ml, respectively. Protopine, a protopine alkaloid, also inhibited the growth of the bacterium, with a MIC50 of 100 microg/ml. The crude methanol extract of H. canadensis rhizomes was very active, with an MIC50 of 12.5 microg/ml. Two isoquinoline alkaloids, berberine and beta-hydrastine, were identified as the active constituents, and having an MIC50 of 12.5 and 100.0 microg/ml, respectively.     

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 and anti-inflammatory activity of folklore: Mallotus peltatus leaf extract

Since ages Mallotus peltatus (Geist) Muell. Arg. var acuminatus (Euphorbiaceae) leaf and stem bark is used in folk medicine to cure intestinal ailments and skin infections. In several intestinal ailments, localized inflammation is of common occurrence and hence we have evaluated the antimicrobial as well as anti-inflammatory activity of M. peltatus leaf extract. The crude methanol extract of M. peltatus leaves was found to be active against Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus faecalis, Bacillus subtilis, Escherichia coli and Proteus mirabilis and the dermatophytic fungi Microsporum gypseum. The minimum inhibitory concentration (MIC) ranges from 128 to 2000 microg ml(-1) for bacteria and 128 mg ml(-1) for fungi, while the minimum bactericidal concentration (MBC) was 2-4-fold higher than MIC. The methanol-water fraction of the extract showed similar activity against Staphylococcus, Streptococcus, Bacillus and Proteus isolates. The anti-inflammatory activity of the extract against carrageenan (acute model) and dextran-induced (subacute model) rat paw oedema and cotton pellet-induced granuloma (chronic model) in rats were studied using indomethacin (10 mg kg(-1)), a nonsteroid anti-inflammatory drug, as standard. The methanol extract at 200 and 400 mg kg(-1), and the n-butanol fractions A and B at 25 mg kg(-1), exhibited significant anti-inflammatory activity in Albino rats, compared with indomethacin. Phytochemical study revealed the presence of tannins, saponins, terpenoids, steroids and reducing sugars in the crude extract while the n-butanol fractions showed the presence of ursolic acid, beta-sitosterol and some fatty acids as major compounds. Further study with fractions showed that the antibacterial and anti-inflammatory activity is due to either fraction A (ursolic acid) alone or the combination of fractions A and B (beta-sitosterol and fatty acids) of the extract.     

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.     

Cancer prevention and therapy with kiwifruit in Chinese folklore medicine: a study of kiwifruit extracts

Kiwi gold fruits were extracted successively with hexane, acetone, methanol and 70% methanol, and further fractionated by silica gel and ODS column chromatographies for the assays of various biological activities. Five fractions H1, H2 (hexane extract), Al, A2 (acetone extract) and M2 (methanol extract) showed selective cytotoxic activity against human oral tumor cell lines, which was more sensitive than human gingival fibroblasts. More hydrophilic fractions [70M3, 70M4, 70M5] of 70% methanol extract displayed higher anti-HIV activity, radical generation and O2- scavenging activity. The antibacterial activity of 70% methanol extracts [70M0, 70M1, 70M2, 70M3, 70M4] was generally lower than that of more lipophilic fractions (hexane, acetone, methanol extracts), although each fraction did not show any specific antimicrobial action. All fractions were inactive against Helicobacter pylori. These results demonstrate that gold kiwifruit extracts contain valuable, various bioactive materials, which can be separated with each other.     

Antibacterial activity of Aristolochia paucinervis Pomel

Several fractions of the methanolic extract of the rhizome or the leaves of Aristolochia paucinervis Pomel were screened for antibacterial activity using the agar dilution method against fourteen reference bacterial strains. Only three fractions (defatted chloroformic rhizome fraction: APRC, rhizome ethyl acetate fraction: APRE and leaf chloroform fraction: APLC) showed an activity against at least one of the microorganisms tested. The minimum inhibitory concentration (MIC) determination showed that APRC was the most active against Clostridium perfringens, Clostridium difficile, Enterococcus faecalis, Micrococcus luteus and Bacillus subtilis. The high bacteriostatic activity of APRC was confirmed by its MIC determination against clinical strains of C. perfringens (n = 32), C. difficile (n = 31), and E. faecalis (n = 22). Results of this study suggest the potential interest of this highly active fraction and support the use of A. paucinervis Pomel in Moroccan traditional medicine to treat skin and soft-tissue infections, especially gas gangrene and intestinal diseases.     

Antidermatophytic properties of extracts from the leaves of Aristolochia paucinervis Pomel

Several fractions of a methanol extract from the leaves of Aristolochia paucinervis Pomel (Aristolochiaceae) were screened for their antidermatophytic efficiency against different human pathogenic fungi responsible for tinea and other skin infections. The antifungal study was carried out by the macrodilution agar method and the results showed that, with the exception of the aqueous fraction, all the fractions exhibited antifungal activities against the dermatophytic fungi tested. The hexane fraction was found to be the most effective (MIC range: 64-2048 microg/mL), whereas the butanol fraction was the least active (MIC range: 1024 microg/mL to more than 2048 microg/mL). The most susceptible fungi were Epidermophyton floccosum and Trichophyton violaceum in contrast to Trichophyton mentagrophytes and Trychophyton rubrum which were less sensitive to the fractions tested. The effects were compared with those of ketoconazole, amphotericin B and griseofulvin, for which MIC ranges were, respectively, 0.12-4 microg/mL, 0.5-4 microg/mL and 0.5-2 microg/mL.     

In vitro anti-mycobacterial activities of three species of Cola plant extracts (Sterculiaceae)

Extracts obtained from three Nigerian Sterculiaceae plants: Cola accuminata, C. nitida and C. milleni were screened for anti-mycobacterium properties using a slow growing Mycobacterium bovis ATCC 35738 (designated BCG Mexican and known to have some virulence in mouse and guinea pig) at 1000 microg/ml using the radiometric (BACTEC) method. The extracts were also tested against six fast growing ATCC strains of M. vaccae using the broth microdilution method.The methanol extracts from both leaves, stem bark and root bark of Cola accuminata and from the leaves and stem bark of C. nitida and C. milleni were not active at the highest concentration of 1000 microg/ml. Only the methanol extract of root bark for both C. nitida and C. milleni were found to be potent against both M. bovis and strains of M. vaccae. The minimum inhibitory concentration (MIC) of C. nitida against M. bovis is 125 microg/ml while the MIC of C. milleni against M. bovis is 62.5 microg/ml after at least 6 days of inhibition with growth index (GI) units lesser than or equal to the change in GI units inoculated with a 1/100 of the BACTEC inoculum for a control vial.The minimum inhibitory concentration of C. milleni against the six ATCC strain of M. vaccae ranged from 62.5 microg/ml to 250 microg/ml while for C. nitida ranged from 500 microg/ml to above 1000microg/ml. Evidently, C. milleni has the highest inhibitory activity against both M. bovis and strains of M. vaccae used. Rifampicin, the positive control used has strong activity against M. bovis at the tested concentration of 5 microg and 10 microg/ml and 4 to 8 microg/ml against the six strains of M. vaccae.     

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.     

Inhibitory effect of methanol extract of Euonymus alatus on matrix metalloproteinase-9

Various extracts prepared from stems of Euonymus alatus were tested for cytotoxic activity on human hepatocellular carcinoma cell line, Hep3B cells using the XTT assay method. Also, the extracts were investigated the inhibitory effects on matrix metalloproteinase (MMP)-9 activity using gelatin zymography. The methanol extract, hexane and ethyl acetate fraction exhibited weak cytotoxic activity (IC(50) of >100 microg/ml). However, butanol (IC(50)=65 microg/ml) and chloroform (IC(50)=85 microg/ml) fraction exhibited strongly cytotoxic activity. Gelatin zymography showed that the Hep3B cells secreted matrix metalloproteinase (MMP), probably including MMP-9, which may be involved in tumor cell invasion and metastasis. The butanol fraction showed stronger inhibitory effect of proteolytic activity than other fractions. Also, the butanol fraction was able to decrease the proteolytic activity of MMP-9 in a concentration-dependent manner on zymography. These results suggest that the butanol fraction from E. alatus has highly inhibitory effect on MMP-9 in comparatively low cytotoxicity.     

In vivo anti-inflammatory activity of Alchornea cordifolia (Schumach. & Thonn.) Müll. Arg. (Euphorbiaceae)

Alchornea cordifolia (Schumach. & Thonn.) Müll. Arg. (Euphorbiaceae) is a widely distributed plant in Africa. It is used in the traditional medicine of many African countries for the treatment of bacterial, fungal, parasitic and inflammatory disorders. Aqueous decoction and methanol leaf extracts were tested for their ability to reduce Croton oil-induced oedema in the mouse ear, after topical application. The methanol leaf extract dose-dependently inhibited the Croton oil-induced ear oedema in mice (ID(50)<500 microg/cm(2)). A bio-assay guided liquid-liquid fractionation of this methanol extract gave four active fractions: water insoluble (F1), hexane (F2), ethyl acetate (F3) and water (F4). The hexane fraction showed a very high activity (42% inhibition at 0.7 microg/cm(2)) as compared to the control. The other fractions were less active (F1: 56% at 506.2 microg/cm(2); F3: 57% at 289.3 microg/cm(2); F4: 32% for 203.8 microg/cm(2)) while indomethacin gave 49% of inhibition at 90 microg/cm(2). The activity of F1 and F3 may be at least in part explained by the presence of anti-inflammatory flavonoids (hyperoside and quercitrin, quercitrin being identified in the plant for the first time) while the activity was not correlated to the tannin contents. None of these compounds were detected in the most active F2 fraction. These results support the reported traditional use of this plant against topical inflammatory disorders.     

In vitro cytotoxic, antileishmanial and antifungal activities of ethnopharmacologically selected Gabonese plants

Seventy-seven crude extracts from leaves and stem barks of 15 Gabonese plants used in traditional medicine were evaluated for their cytotoxic, antileishmanial and antifungal activities. Most of the extracts exhibited cytotoxic activities toward human monocytes, and most particularly the hydromethanolic 50% (v/v) fraction of Ganophyllum giganteum leaves (IC(50)=1.3 microg/ml) as well as the methanolic extracts of Polyalthia suaveolens, Dioscorea preussii, Augouardia letestui leaves and Cola lizae stem barks (IC(50)<5 microg/ml). The methanolic extract of Polyalthia suaveolens displayed a strong antiproliferative activity against the promastigote form of Leishmania infantum parasites and presented a good antifungal activity on all the tested strains (IC(50)<1mg/ml). This extract was divided into six fractions: fraction F6 demonstrated a cytotoxic activity stronger than those of the crude extract (IC(50)=0.6 microg/ml), fractions F4 and F5 were devoid of cytotoxicity (IC(50)>100 microg/ml) and displayed interesting antileishmanial activity against the intracellular amastigote form of the parasite (IC(50)=5.6 and 12.4 microg/ml), respectively. However, the antifungal activity observed for the crude extract could not be recovered in the corresponding fractions.     

Antimicrobial activity of Alstonia macrophylla: a folklore of bay islands

The methanolic crude and methanol-aqueous extract of Alstonia macrophylla leaves and n-butanol part of the crude extract showed antimicrobial activity against various strains of Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus faecalis, Escherichia coli, Proteus mirabilis, Trichophyton rubrum, Trichophyton mentagrophytes var. mentagrophytes and Microsporum gypseum. The minimum inhibitory concentration (MIC) values ranges from 64 to 1000 microg/ml for bacteria and 32-128 mg/ml for dermatophytes. However, the strains of Pseudomonas aeruginosa, Klebsiella sp. and Vibrio cholerae showed resistance against in vitro treatment of the extracts up to 2000 microg/ml concentration, while the two yeast species were resistant even at 128 mg/ml concentration. The stem bark extract prepared similarly was found to be less active compared to the leaves. Phytochemical study indicates that the crude extract contains tannins, flavonoids, saponins, sterols, triterpene and reducing sugars. Further fractionation and purification of n-butanol part of the extract showed the presence of beta-sitosterol, ursolic acid, beta-sitosterol glucoside and a mixture of minor compounds only detected in TLC.     

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.     

Activity against multidrug-resistant Mycobacterium tuberculosis in Mexican plants used to treat respiratory diseases

The increase of multidrug-resistant Mycobacterium tuberculosis (MDR-TB) demands the search for alternative antimycobacterial drugs. The aim of this study was to evaluate plants used in Mexican traditional medicine to treat respiratory diseases for activity against MDR-TB. A group of 22 plants was screened for activity against Mycobacterium tuberculosis H37Rv and Mycobacterium avium at concentrations from 50 to 200 microg/mL. The antimycobacterial effect was determined by a microcolorimetric assay with Alamar blue dye. None of the aqueous extracts had antimycobacterial activity. Hexane extracts from Artemisia ludoviciana, Chamaedora tepejilote, Lantana hispida, Juniperus communis and Malva parviflora, and methanol extracts from Artemisia ludoviciana and Juniperus communis inhibited the growth of Mycobacterium tuberculosis. Mycobacterium avium was inhibited by Juniperus communis hexane extract and by Malva parviflora methanol extract. The active extracts were tested against monoresistant variants of Mycobacterium tuberculosis H37Rv (isoniazid, rifampin, streptomycin and ethambutol resistant) and the hexane extract of Lantana hispida showed the best activity. Lantana hispida hexane extract was also active against a group of MDR-TB clinical isolates. In contrast, it did not inhibit the growth of non-tuberculous mycobacteria. The hexane extract of Lantana hispida was fractionated by column chromatography and one of its fractions (FVI) inhibited the growth of all the MDR-TB clinical isolates at concentrations up to 25 microg/mL. This study supports the fact that selecting plants by ethnobotanical criteria enhances the probability of finding species with activity against mycobacteria, and our results point to Lantana hispida as an important source of potential compounds against MDR-TB.     

Antimicrobial activities of Barringtonia acutangula

Crude extracts and VLC fractions from the stem bark of Barringtonia acutangula (L.) Gaertn (Fam. Lecythidaceae) were screened for their antimicrobial activities against two Gram-positive bacteria, two Gram-negative bacteria and two fungi using a microdilution titre assay. Among the crude extracts, petroleum ether extract showed good activity against all test organisms. The VLC fraction PE 16 was found to be very effective against Bacillus subtilis (MIC=25 microg/ml) and Aspergillus niger (MIC=12.5 microg/ml). The activities were compared to standard antibiotics-kanamycin and fluconazole. The major compound from PE16 was identified as 12, 20(29)-lupadien-3-ol by NMR spectroscopy.     

Cinnamon extracts' inhibitory effect on Helicobacter pylori

Ethanol and methylene chloride extracts of cinnamon were compared for their effect on Helicobacter pylori growth and urease activity. Methylene chloride extract was found to inhibit growth of H. pylori, while ethanol extract counteracted its urease activity. Cinnamon extract (from methylene chloride) inhibited H. pylori at concentration range of common antibiotics. Complete inhibition in vitro was achieved by 50 microg/ml in solid medium (egg yolk emulsion agar) and by 15 microg/ml in liquid medium (supplemented brain heart infusion broth). The cinnamon extracts were more inhibitory on free urease than on whole cell urease.     

Antibacterial and antioxidant activities in Sideritis italica (Miller) Greuter et Burdet essential oils

Sideritis italica (Miller) Greuter et Burdet is a widespread Lamiacea in the Mediterranean region used in traditional medicine. Essential oils were antibacterial against nine ATCC and as many clinically isolated Gram-positive and Gram-negative bacterial strains. Antibacterial activity was also found against Helicobacter pylori: a dose-dependant inhibition was shown between 5 and 25 microg/ml. The antibacterial activity of the oils was expressed as MICs (minimum inhibitory concentrations) and MBCs (minimum bactericidal concentrations). At a concentration between 3.9 and 250 microg/ml the oils showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In particular the ATCC strains Pseudomonas aeruginosa (MIC=3.9 microg/ml and 7.8 for flowerheads and leaves, respectively), Proteus mirabilis (MIC=15.6 and 7.8 microg/ml), Salmonella typhi (MIC=7.8 microg/ml) and Proteus vulgaris (MIC=15.6 microg/ml) were the most inhibited. Only Pseudomonas aeruginosa showed MBC at a concentration between 62.6 and 125 microg/ml. The antioxidant activity of the essential oils was evaluated by two cell free colorimetric methods: ABTS and DMPD; leaf oil is more active (4.29 +/- 0.02 trolox equivalents and 4.53 +/- 0.67 ascorbic acid equivalents by ABTS and DMPD, respectively). Finally the antioxidant activity of the essential oils was also evaluated by their effects on human whole blood leukocytes (WB) and on isolated polymorphonucleate (PMN) chemiluminescence. Comparing the effects of the oils from leaves and flowerheads on both PMN and WB chemiluminescence emission, we found no significant differences. Essential oils showed a dose-dependent and linear inhibitory activity on isolated PMN as well as on WB CL emission when PMA-stimulated. On the contrary, the inhibitory activity on resting cells was nonlinear. Our data represent an answer to the continual demand for new antibiotics and antioxidants for the continuous emergence of antibiotic-resistant strains and the growing interest in the substitution of synthetic antioxidants with natural ones. Furthermore, our finding of antibacterial and antioxidant activities in the essential oils from Sideritis italica flowerheads and leaves validated the use of the plant for medical purposes.     

3-Farnesyl-2-hydroxybenzoic acid is a new anti-Helicobacter pylori compound from Piper multiplinervium

A new prenylated salicylic acid derivative, 3-farnesyl-2-hydroxy benzoic acid (1), was isolated from the leaves of Piper multiplinervium C. DC. (Piperaceae). It showed anti-Helicobacter pylori activity (MIC 37.5 microg/ml) and antimicrobial activity at MICs between 2.5 and 5 microg/ml against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Mycobacterium smegmatis, Pseudomonas aeruginosa and Candida albicans. Its structure was elucidated by means of MS, 1H and 13C NMR. The ethnomedical claim of Piper multiplinervium to treat stomach aches by the Kuna Indians of Panama may be justified by anti-Helicobacter pylori activity of its MeOH extract.