Antimicrobial activity of the extracts of Craniotome furcata (Lamiaceae)

Ethnopharmacological relevance

Craniotome furcata (Link.) O. Kuntze (Lamiaceae) is used in the traditional medicine for the treatment of cuts and wounds indicating antimicrobial activity.

Aim of the study

To validate the traditional medicinal claim, in vitro antimicrobial activity of the extracts was screened against eleven human pathogenic bacteria and fungi.

Materials and methods

The ethyl acetate (CE) and n-butanol (CB) extracts of the aerial parts of Craniotome furcata were tested against four Gram-positive bacteria, four Gram-negative bacteria and three fungi species. Antimicrobial activity was determined by the tube-dilution method.

Results

The CE and CB extracts showed antimicrobial activity against all of the tested microorganisms, with minimum inhibitory concentration (MIC) values in the range of 0.41–4.58 mg/ml.

Conclusions

The tested microbes Micrococcus flavus and Escherichia coli were highly susceptible to extract CE and antimicrobial activity of CB is comparable to that of extract CE against Escherichia coli and Staphylococcus faecalis while it is better than that of extract CE, against Klebsiella pneumoniae. Both the extracts were found less susceptible against tested fungi.     

In vitro antimicrobial activity of extracts and compounds of some selected medicinal plants from Cameroon

Aim of the study

Seven extracts and eight compounds from four selected Cameroonian medicinal plants, Solanecio mannii Hook f. (Asteraceae), Monodora myristica Dunal (Annonaceae), Albizia gummifera (J.F. Gmel) C.A. Smith (Fabaceae/Mimosoideae) and Glyphaea brevis (Spreng) Monachino (Tiliaceae), traditionally used for the treatment of hepatitis, parasites and other infectious diseases, were tested in vitro for their antimicrobial activity against Gram-positive (5 species) and Gram-negative (4 species) bacteria species and pathogenic yeasts (2 Candida species), to establish whether or not they have antimicrobial activity and to validate scientifically their use in traditional medicine.

Materials and methods

The agar disc diffusion and the microbroth dilution methods were used to determine the zone of inhibition between the edge of the filter paper and the edge of the inhibition area (IZ) and the minimal inhibitory concentration (MIC) respectively.

Results

The most active extracts against Candida albicans and Candida krusei were respectively the cyclohexane extract from the fruits of Monodora myristica and the ethyl acetate extract from the stem bark of Albizia gummifera (MIC = 6.3 μg/ml for both extracts). The lowest MIC value (1.6 μg/ml) for purified compounds was obtained on Candida albicans with a mixture of linear aliphatic primary alcohols (n-C24H50O to n-C30H62O), with n-hexacosanol (1b) as major compound and mixture of fatty acid esters of diunsaturated linear 1,2-diols (6).

Conclusion

These results afford ground informations for the potential use of the crude extracts of these species as well as of some of the isolated compounds in bacterial and fungal infections.     

Antimicrobial activity of the methanolic extracts and compounds from Treculia obovoidea (Moraceae)

The crude extract from Treculia obovoidea was subjected to purification by repeated chromatography. Eight compounds were isolated from Treculia obovoidea and identified as Psoralen (1), Bergapten (2), 7-methoxycoumarin (3), 7-hydroxycoumarin (4), 4,2′,4′-trihydroxychalcone (5), 4,2′,4′-trihydroxy-3-prenylchalcone (6), 3-hydroxy-4-methoxybenzoic acid (7) and O-[3-(2,2-dimethyl-3-oxo-2H-furan-5-yl) butyl] bergaptol (8). These compounds together with the extract were tested for their antimicrobial activity against Gram-positive bacteria (six species), Gram-negative bacteria (12 species) and three Candida species using micro-dilution methods for the determination of the minimal inhibition concentration (MIC) and the minimal microbicidal concentration (MMC). The MIC values obtained with the crude extracts varied from 78.12 to 156.25 μg/ml against 17 (80.95%) of the 21 tested microorganisms. All the isolated compounds showed selective activity. The antimicrobial activity of this plant as well as that of compounds 6 and 8 is being reported for the first time. The obtained results provide promising baseline information for the potential use of these crude extract as well as some of the isolated compounds in the treatment of bacterial and fungal infections.     

儿茶化学成分研究

目的:研究儿茶Acacia catechu的化学成分。方法:应用正相硅胶、Sephadex LH-20、ODS等柱色谱技术及重结晶等方法分离纯化,通过理化性质和波谱学方法鉴定化合物的结构。结果:从儿茶乙酸乙酯部位中分离出12个化合物,分别鉴定为对-羟基苯甲酸(4-hydroxybenzoic acid,1)、山柰酚(kaempferol,2)、槲皮素(quercetin,3)、3,4′,7-三羟基-3′,5-二甲氧基黄酮(3,4′,7-trihydroxyl-3′,5-dimethoxyflavone,4)、儿茶素(catechin,5)、表儿茶素(epicatechin,6)、阿福豆素(afz-elechin,7)、表阿福豆素(epiafzelechin,8)、mesquitol(9)、ophioglonin(10),香橙素(aromadendrin,11)和苯酚(phenol,12)。结论:化合物7,12为从该植物首次分离得到,化合物4,9~11为从该属植物首次分离得到。     

Screening of the topical anti-inflammatory activity of the bark of Acacia cornigera Willdenow, Byrsonima crassifolia Kunth, Sweetia panamensis Yakovlev and the leaves of Sphagneticola trilobata Hitchcock

Ethnopharmacological relevance

An investigation of topical anti-inflammatory activity was undertaken on plants used in Central America traditional medicine.

Aim of study

Four herbal drugs used in the folk medicine of Central America to treat inflammatory skin affections (Acacia cornigera bark, Byrsonima crassifolia bark, Sphagneticola trilobata leaves and Sweetia panamensis bark) were evaluated for their topical anti-inflammatory activity.

Materials and methods

Petroleum ether, chloroform and methanol extracts were obtained for herbal medicines and then extracts were tested on Croton oil-induced ear dermatitis model in mice.

Results

Almost all the extracts reduced the Croton oil-induced ear dermatitis in mice and the chloroform ones showed the highest activity, with ID₅₀ (dose giving 50% oedema inhibition) values ranging from 112 μg/cm² (Byrsonima crassifolia) to 183 μg/cm² (Sphagneticola trilobata). As reference, ID₅₀ of the non-steroidal anti-inflammatory drug indomethacin was 93 μg/cm².

Conclusions

Lipophilic extracts from these species can be regarded as potential sources of anti-inflammatory principles.     

Anthelmintic activity of Ziziphus nummularia (bark) and Acacia nilotica (fruit) against Trichostrongylid nematodes of sheep

Ethnopharmacological relevance

Ziziphus nummularia (Rhamnaceae) and Acacia nilotica (Fabaceae) are being used as anthelmintics in ethnoveterinary medicinal system of Pakistan.

Aim of the study

Present study was conducted to determine the anthelmintic activity of Ziziphus nummularia (bark) and Acacia nilotica (fruit) in order to justify their traditional use in veterinary medicine.

Materials and methods

In vitro anthelmintic activity of crude methanolic extract (CME) of both the plants was determined against Haemonchus contortus by the adult motility assay, the egg hatch test and the larval development assay. In vivo anthelmintic activity was evaluated in sheep naturally infected with gastrointestinal nematodes by administering increasing doses of crude powder (CP) and CME (1.0–3.0 g/kg).

Results

Both the plants exhibited dose- and time-dependent anthelmintic effects by causing mortality of worms, and inhibiting egg hatching and larval development. Acacia nilotica (LC₅₀ = 512.86 and 194.98 μg/ml) was found to be more potent than Ziziphus nummularia (LC₅₀ = 676.08 and 398.11 μg/ml) in egg hatch test and larval development assay, respectively. In vivo, maximum fecal egg count reduction (84.7%) was recorded on day 13 post-treatment in sheep treated with Ziziphus nummularia CME (3.0 g/kg) followed by 78.5% on same day with Acacia nilotica CME (3.0 g/kg).

Conclusions

These data show that both Ziziphus nummularia and Acacia nilotica possess anthelmintic activity in vitro and in vivo, justifying their use in traditional veterinary medicine in Pakistan.     

Antimicrobial activity of Schinus lentiscifolius (Anacardiaceae)

Ethnopharmacological relevance

Schinus lentiscifolius Marchand (syn. Schinus weinmannifolius Engl) is a plant native to Rio Grande do Sul (Southern Brazil) and has been used in Brazilian traditional medicine as antiseptic and antimicrobial for the treatment of many different health problems as well as to treat leucorrhea and to assist in ulcer and wound healing. Although it is a plant widely used by the population, there are no studies proving this popular use.

Material and methods

The crude aqueous extract, the crude neutral methanol extract, fractions prepared from this extract (n-hexane, ethyl acetate, and n-butanol), pure compounds isolated from these fractions, and derivatives were investigated in vitro for antimicrobial activities against five Gram positive bacteria: Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Streptococcus pyogenes, three Gram negative bacteria: Escherichia coli, Pseudomonas aeruginosa, and Shigella sonnei, and four yeasts: Candida albicans, Candida tropicalis, Cryptococcus neoformans, and Saccharomyces cerevisiae. The isolated compound moronic acid, which is the most active, was tested against a range of other bacteria such as two Gram positive bacteria, namely, Bacillus cereus, Enterococcus spp, and six Gram negative bacteria, namely, Burkholderia cepacia, Providencia stuartii, Morganella morganii, Enterobacter cloacae, Enterobacter aerogenes, and Proteus mirabilis.

Results

The leaf aqueous extract (decoction) of Schinus lentiscifolius showed a broad spectrum of antibacterial activity, ranging from 125 to 250 μg/ml (MIC) against the tested bacteria and fungi. The n-hexane extract, despite being very little active against bacteria, showed an excellent antifungal activity, especially against Candida albicans (MIC=25 μg/ml), Candida tropicalis (MIC=15.5 μg/ml), and Cryptococcus neoformans, (MIC=15.5 μg/ml). From the acetate fraction (the most active against bacteria), compounds 1–6 were isolated: nonadecanol (1), moronic acid (2), gallic acid methyl ester (3), gallic acid (4), quercetin (5) and quercitrin (6). The minimal inhibitory concentration (MIC) of moronic acid between 1.5 and 3 μg/ml against most of the tested bacteria shows that it is one of the metabolites responsible for the antibacterial activity of Schinus lentiscifolius.

Conclusion

The antimicrobial activity and some constituents of Schinus lentiscifolius are reported for the first time. The results of the present study provide scientific basis for the popular use of Schinus lentiscifolius for a number of different health problems.     

In vitro biological activities of niloticane,a new bioactive cassane diterpene from the bark of Acacia nilotica subsp. kraussiana

Ethnopharmacological relevance

Acacia nilotica subsp. kraussiana was reported in African traditional medicine for the treatment of various ailments. Isolation of an active compound in this study from the bark extract may lead to the validation of its efficiency as a traditional crude drug.

Aims of the study

This study aimed to isolate active compound(s) from an ethyl acetate bark extract of Acacia nilotica subsp. kraussiana and to investigate some of its biological activity.

Materials and methods

The isolation process was carried out using bioassay-guided fractionation. The isolated compound was tested for antibacterial activity using the micro-dilution assay; anti-inflammatory activity using the COX-1 and COX-2 assays and investigated for inhibitory effect against acetylcholinesterase using the microplate assay.

Results

A new bioactive compound was isolated and identified as a cassane diterpene, niloticane. Niloticane showed antibacterial activity against Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus with MIC values of 4 and 8 μg/mL, respectively. With Gram-negative bacteria, niloticane showed weak activity. MIC values obtained were 16 and 33 μg/mL against Klebsiella pneumonia and Escherichia coli, respectively. In the cyclooxygenase test, niloticane possessed activity with IC₅₀ values of 28 and 210 μM against COX-1 and COX-2, respectively. IC₅₀ values observed with indomethacin (positive control) were 3.6 μM for COX-1 and 189 μM for COX-2. In the acetylcholinesterase test, niloticane showed anti-cholinesterase activity with an IC₅₀ value of 4 μM. IC₅₀ values obtained by the galanthamine (positive control) was 2.0 μM.

Conclusion

The results obtained support the traditional uses of the bark of Acacia nilotica subsp. kraussiana in African traditional medicine for the treatment of some ailments that relate to microbial diseases, inflammation and central nervous system disorders.     

Antimicrobial activity of the methanolic extract and compounds from Morus mesozygia stem bark

Aim of the study

This study was aimed at investigating the antimicrobial activity of the methanolic extract (MMB) and compounds isolated from the stem bark of Morus mesozygia, namely 3β-acetoxyurs-12-en-11-one (1), moracin Q (2), moracin T (3), artocarpesin (4), cycloartocarpesin (5), moracin R (6), moracin U (8), moracin C (9), and moracin M (10).

Materials and Methods

The liquid microdilution assay was used in the determination of the minimal inhibitory concentration (MIC) and the minimal microbicidal concentration (MMC), against nine bacterial and two fungal species.

Results

The results of the MIC determination showed that the compounds 3, 4, 8 and 9 were able to prevent the growth of all tested microbial species. All other samples showed selective activities. Their inhibitory effects were noted on 90.9% studied organisms for the crude extract, 81.8% for compound 6, 72.7% for compound 10, 63.6% for compound 1, 54.5% for compound 5, and 45.5% for compound 2. The lowest MIC value of 39 μg/ml was obtained with the crude extract against Escherichia coli. The corresponding value for compounds (5 μg/ml) was registered with compound 9 on Shigella dysenteriae and compound 3 on E. coli, S. dysenteriae, Pseudomonas aeruginosa, Salmonella typhi and Bacillus cereus. The lowest MIC value (39 μg/ml) observed with the crude extract (on E. coli) was only eightfold greater than that of gentamycin used as reference antibiotic (RA) while the corresponding value (5 μg/ml) recorded with compounds 3 and 9 was equal to that of RA on the corresponding microorganisms.

Conclusions

The obtained results highlighted the interesting antimicrobial potency of M. mesozygia as well as that of the studied compounds, and provided scientific basis for the traditional use of this species.     

Diuretic activity of the ethanol and aqueous extracts of the surface layer of Poria cocos in rat

Ethnopharmacological relevance

Poria cocos Wolf (Polyporaceae) is a well-known traditional East-Asian medicinal fungus. the epidermis (“Fu-Ling-Pi” in Chinese) of the sclerotia is used as a diuretic. This study was conducted to evaluate of ethanol extract (EE) and aqueous extract (AE) of the diuretic activity of Fu-Ling-Pi in saline-loaded rats.

Material and methods

The EE and AE were orally administered to rats. Urinary excretion rate, pH and electrolyte excretion were measured in the urine of saline-loaded rats.

Results

Urinary excretion rates were significantly increased by the EE. The three doses of AE only produced a slight increase urinary output. The EE had little or no effect on K⁺ excretion, but did indeed induce a notable excretion of Na⁺, that was in agreement with the urinary excretion. The three doses of AE produced an increase Na⁺ and K⁺ excretion, but did not arrive at statistical significance.

Conclusions

The present study confirmed that the not aqueous but ethanol extracts of the epidermis of Poria cocos presents a remarkable diuretic effect.     

In vitro and in vivo trypanocidal effect of lipophilic extracts of medicinal plants from Mali and Burkina Faso

AIM OF THE STUDY: To determine the in vitro and in vivo antitrypanosomal activity of extracts of traditionally used plants. MATERIALS AND METHODS: 47 dichloromethane extracts were tested in vitro in the Long-term Viability Assay (LtVA) on Trypanosoma brucei brucei. The most active ones were also tested in vivo using a standardised mouse test. RESULTS: 13 extracts (28%) were active in vitro with MIC-values相似文献   

Evaluation of the toxicity and antimicrobial activity of hydroethanolic extract of Arrabidaea chica (Humb. & Bonpl.) B. Verl.

Ethnopharmacological relevance

Arrabidaea chica (Bignoniaceae) is a vine native to the Amazon Rainforest, popularly known as “crajiru” and whose infusion and decoction of the leaves are used to treat diseases such as gastric ulcers, inflammations, infections, anemia, herpes, jaundice among others. It is also used as a natural dye. This work aimed to evaluate the in vitro and in vivo toxicity, antimicrobial activity including analysis of chemical constitution of the hydroethanolic extract of the leaves of Arrabidaea chica (HEAc).

Materials and methods

Acute and subchronic toxicity of HEAc was evaluated in mice and rats, respectively, and by Alamar blue (cytotoxicity assay) using CHO-K1 cells. Antimicrobial activity of HEAc was tested by broth microdilution method using a panel of bacteria and yeast of clinical interest. The preliminary phytochemical analysis of HEAc was performed by electrospray ionization mass spectrometry [ESI(+)–MS]. Secondary metabolites were quantified by colorimetric methods.

Results

When administered in vivo at doses up to 3000 mg/kg v.o., HEAc did not cause any signs and symptoms of acute toxicity in mice and no cytotoxicity in CHO-K1 cells. Administration for 30 days caused leukocytosis (200 mg/kg) and reversible reductions in non-dose dependent of body weight, total weight gain and feed intake in rats given 200 mg/kg and 500 mg/kg of HEAc, but were not accompanied by behavioral and clinical changes (laboratory and histopathological) that may have demonstrated evidences of subchronic toxicity HEAc demonstrated a pronounced activity against Helicobacter pylori (MIC=12.5 μg/mL) and moderate activity against Enterococcus faecalis (MIC=100 μg/mL) in broth microdilution. Preliminary phytochemical analysis of HEAc by colorimetric methods revealed that mainly the presence of phenolic compounds (16.6%), especially flavones and flavonols (4.02%). [ESI(+)–MS] fingerprint analyses of HEAc revealed the presence of 3-deoxyanthocyanidins and kaempferol.

Conclusion

Our data provide evidence that HEAc is safe and can be useful in infections related to Helicobacter pylori and Enterococcus faecalis. Phytochemical analysis revealed the predominant presence of flavones and flavonols, possibly involved in the antimicrobial action of HEAc.     

Antitubercular activity of Arctium lappa and Tussilago farfara extracts and constituents

Ethnopharmacological relevance

Arctium lappa and Tussilago farfara (Asteraceae) are two plant species used traditionally as antitubercular remedies. The aim of this study was (i) to screen Arctium lappa and Tussilago farfara extracts for activity against Mycobacterium tuberculosis and (ii) to isolate and identify the compound(s) responsible for this reputed anti-TB effect.

Materials and methods

The activity of extracts and isolated compounds was determined against Mycobacterium tuberculosis H₃₇R_v using a high throughput spot culture growth inhibition (HT-SPOTi) assay.

Results

The n-hexane extracts of both plants, the ethyl acetate extract of Tussilago farfara and the dichloromethane phase derived from the methanol extract of Arctium lappa displayed antitubercular activity (MIC 62.5 μg/mL). Further chemical investigation of Arctium lappa led to the isolation of n-nonacosane (1), taraxasterol acetate (2), taraxasterol (3), a (1:1) mixture of β sitosterol/stigmasterol (4), isololiolide (5), melitensin (6), trans-caffeic acid (7), kaempferol (8), quercetin (9), kaempferol-3-O-glucoside (10). Compounds isolated from Tussilago farfara were identified as a (1:1) mixture of β sitosterol/stigmasterol (4), trans-caffeic acid (7), kaempferol (8), quercetin (9), kaempferol-3-O-glucoside (10), loliolide (11), a (4:1) mixture of p-coumaric acid/4-hydroxybenzoic acid (12), p-coumaric acid (13). All compounds were identified following analyses of their physicochemical and spectroscopic data (MS, ¹H and ¹³C-NMR) and by comparison with published data. This is the first report of the isolation of n-nonacosane (1), isololiolide (5), melitensin (6) and kaempferol-3-O-glucoside (10) from Arctium lappa, and of loliolide (11) from Tussilago farfara. Amongst the isolated compounds, the best activity was observed for p-coumaric acid (13) (MIC 31.3 μg/mL or 190.9 μM) alone and in mixture with 4-hydroxybenzoic acid (12) (MIC 62.5 μg/mL).

Conclusions

The above results provide for the first time some scientific evidence to support, to some extent, the ethno-medicinal use of Arctium lappa and Tussilago farfara as traditional antitubercular remedies.     

四合木中三萜类成分及其免疫抑制活性

目的:研究四合木Tetraena mongolica的化学成分及其生物活性.方法:采用硅胶柱色谱、凝胶柱色谱和HPLC制备色谱方法分离纯化得到单体化合物,采用有机波谱方法鉴定化合物结构,进一步以MTT比色法测定化合物对淋巴细胞转化的作用.结果:从四合木醋酸乙酯提取物中分离得到6个三萜类化合物,分别为3β-hydroxy-11α,12α:13β,28-diepoxyolean-ane(1),3β(3,4-dihydroxycinnamoyl)-erythrodi-ol(2),olean-28-al-3β-yl-caffeate(3),古柯二醇(4),12-oleanane-3β-caffeate(5),3-O-(E)-coumaroylerythrodiol(6).淋巴细胞转换实验结果表明化合物2～4在30 mg·L~(-1)时的抑制率均大于50%.结论:化合物1～6均为首次从该属中分离得到,其中化合物1为新天然产物;化合物2～4具有较强的免疫抑制活性.     

In vivo antimalarial activity of Keetia leucantha twigs extracts and in vitro antiplasmodial effect of their constituents

Ethnopharmacological relevance

The West African tree Keetia leucantha (Rubiaceae) is used in traditional medicine in Benin to treat malaria. The twigs dichloromethane extract was previously shown to inhibit in vitro Plasmodium falciparum growth with no cytotoxicity (>100 µg/ml on human normal fibroblasts).

Materials and methods

The dichloromethane and aqueous extracts of twigs of K. leucantha were evaluated in vivo against Plasmodium berghei NK 173 by the 4-day suppressive test and in vitro against a chloroquine-sensitive strain of Plasmodium falciparum (3D7) using the measurement of the plasmodial lactate dehydrogenase activity. Bioguided fractionations were realized and compounds were structurally elucidated using extensive spectroscopic analysis.

Results

The in vivo antimalarial activity of K. leucantha dichloromethane and aqueous twigs extracts were assessed in mice at the dose of 200 mg/kg/day. Both extracts exhibited significant effect in inhibiting parasite growth by 56.8% and 53.0% (p<0.0001) on day 7-postinfection. An LC–MS analysis and bioguided fractionations on the twigs dichloromethane extract led to the isolation and structural determination of scopoletin (1), stigmasterol (2), three phenolic compounds: vanillin (3), hydroxybenzaldehyde (4) and ferulaldehyde (5), eight triterpenic esters (6–13), oleanolic acid and ursolic acid. The antiplasmodial activity of the mixture of the eight triterpenic esters showed an antiplasmodial activity of 1.66±0.54 µg/ml on the 3D7 strain, and the same range of activity was observed for isolated isomers mixtures.

Conclusions

This is the first report on the in vivo activity of K. leucantha extracts, the isolation of thirteen compounds and analysis of their antiplasmodial activity. The results obtained may partially justify the traditional use of K. leucantha to treat malaria in Benin.     

Antimicrobial activity of the crude extract,fractions and compounds from stem bark of Ficus ovata (Moraceae)

Aim of the study

This study was designed to investigate the antimicrobial activities of the methanol extracts from the stem bark of Ficus ovata (FOB), fractions (FOB1–6) and compounds isolated following bio-guided fractionation [3-friedelanone (1), taraxeryl acetate (2), betulinic acid (3), oleanoïc acid (4), 2-hydroxyisoprunetin (5), 6,7-(2-isopropenyl furo)-5,2,4-trihydroxyisoflavone (6), Cajanin (7) and protocatechuic acid (8)].

Materials and Methods

The micro-dilution method was used for the determination of the minimal inhibition concentration (MIC) and the minimal microbicidal concentration (MMC) against fungi (two species), Gram-positive (three species) and Gram-negative bacteria (five species).

Results

The results of the MIC determinations indicated that the crude extract (FOB), fractions FOB2 and FOB4 as well as compound 5 were active on the entire studied organisms. Other samples showed selective activity, fractions FOB1, FOB3 and FOB5 being active against 50% of the tested microbial species while FOB6 was active on 40%. Compounds 8, 6, 2 and 7 prevented the growth of 80%, 70%, 50% and 20% of the organisms respectively. The lowest MIC value (156g/ml) observed with the crude extract was recorded on Streptococcus faecalis, Candida albicans and Microsporum audouinii. The corresponding value for fractions (39 μg/ml) was noted with FOB4 against Staphylococcus aureus, while that of the tested compounds (10 μg/ml) was observed with compound 8 on Microsporum audouinii. The results of the MMC determination suggested that the cidal effect of most of the tested samples on the studied microorganisms could be expected.

Conclusions

The overall results provided evidence that the studied plant extract, as well as some of the isolated compounds might be potential sources of new antimicrobial drug.     

Medicinal plant complexes of Salvia subgenus Calosphace: An ethnobotanical study of new world sages

Ethnopharmacological relevance

The species of Salvia subgenus Calosphace are used medicinally and ritually in numerous traditions of folk healing among indigenous cultures of North and South America with more than 500 species. These species contain numerous bioactive terpenes and terpenoids, some active at human opioid and GABA receptors, which may contribute to their effectiveness as folk medicines. Medicinal plant complexes contain species which share common names, morphological and/or aromatic properties, and medicinal uses; these complexes are found in traditional systems of medicine. Our research looks for complexes within Calosphace and the secondary metabolites they contain.

Materials and methods

Several studies have combined molecular phylogenetics and ethnopharmacology to successfully target active medicinal species. In this paper, we have selected a monophyletic clade, Salvia subgenus Calosphace, and performed a literature search to identify medicinal plant complexes within it. We created a database from over 200 references, found using keywords, and herbarium sheets. To identify medicinal plant complexes within the database, all species with shared vernacular names were first grouped. If the species sharing common names had similar medicinal uses and morphological similarity, they were concluded to be a complex. In order to determine the accuracy and validity of this approach, the chia complex was used as control, and we more species than reported by all of the published references combined. After identifying complexes and species within each, we searched the phytochemical literature to identify all reported secondary metabolites for each.

Results

We identify four previously unidentified complexes. Mirto (5 species) is used extensively in the treatment of the folk illness susto and other illnesses in Mexico, and is characterized by red flowers. Ñucchu (7 species) used as a symbolic element in religious processions and in the treatment of respiratory ailments in Peru and characterized by red flowers. Cantueso (2 species), with blue flowers, is used for respiratory ailments in Mexico, and Manga-paqui (3 species) is used for kidney and liver diseases in Ecuador. For the species of each complex we report all traditional preparations, other vernacular names, and known secondary metabolites. Among these complexes, Mirto and Ñucchu appear to have exceptional levels of cultural significance.

Conclusions

Our results support our hypothesis that species within Salvia subgenus Calosphace will assort into complexes of medicinal plants that share common names, appearances, and medicinal uses. We have identified four new complexes within this monophyletic lineage, mirto, ñucchu, cantueso, and manga-paqui.     

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 compounds from Alpinia conchigera

Ethnopharmacological relevance

The rhizome of Alpinia conchigerahas been used as a condiment in the northern states of Peninsular Malaysia and occasionally in folk medicine in the east coast to treat fungal infections. In some states of Peninsular Malaysia, the rhizomes are consumed as a post-partum medicine and the young shoots are prepared into a vegetable dish. This study aimed to investigate the chemical constituents of the pseudostems and rhizomes of Malaysian Alpinia conchigera and to evaluate the antimicrobial activity of the dichloromethane (DCM) extracts of the pseudostems, rhizomes and the isolated compounds against three selected fungi and five strains of Staphylococcus aureus.

Materials and methods

The dried and ground pseudostems (0.8 kg) and rhizomes (1.0 kg) were successively extracted in Soxhlet extractor using n-hexane, dichloromethane (DCM) and methanol. The n-hexane and DCM extracts of the pseudostem and rhizome were subjected to isolation and purification using column chromatography on silica gel using a stepwise gradient system (n-hexane to methanol). Briefly, a serial two fold dilutions of the test materials dissolved in DMSO were prepared prior to addition of 100 μl overnight microbial suspension (108 cfu/ml) followed by incubation at 37 °C (bacteria) or 26 °C (dermatophytes and candida) for 24 h. The highest concentration of DMSO remaining after dilution (5%, v/v) caused no inhibition to bacterial/candida/dermatophytes’ growth. Antibiotic cycloheximide was used as reference for anticandidal and antidermatophyte comparison while oxacilin was used as reference for antibacterial testing. DMSO served as negative control. Turbidity was taken as indication of growth, thus the lowest concentration which remains clear after macroscopic evaluation was taken as the minimum inhibitory concentration (MIC).

Results

The isolation of n-hexane and DCM extracts of the rhizomes and pseudostems of Alpinia conchigera via column chromatography yielded two triterpenes isolated as a mixture of stigmasterol and β-sitosterol: caryophyllene oxide, chavicol acetate 1, p-hydroxy cinnamaldehyde 2, 1′S-1′-acetoxychavicol acetate 3, trans-p-coumaryl diacetate 4, 1′S-1′-acetoxyeugenol acetate 5, 1′-hydroxychavicol acetate 6, p-hydroxycinnamyl acetate 7 and 4-hydroxybenzaldehyde.The DCM extract of the rhizome of Alpinia conchigera indicated potent antifungal activity against Candida albicans, Microsporum canis and Trycophyton rubrum with MIC values of 625 μg/ml, 156 μg/ml and 156 μg/ml, respectively. It also showed significant inhibitory activity with MIC values between 17.88 and 35.75 μg/ml against the mutant Staphylococci isolates MSSA, MRSA and Sa7.Amongst the isolated compounds, the lowest inhibition observed were of 1′S-1′-acetoxyeugenol against the dermatophytes (MIC 313 μg/ml) followed by trans-p-coumaryl diacetate against both dermatophytes and candida (MIC 625 μg/ml). The compound p-hydroxycinnamyl acetate strongly inhibited Staphylococcusaureus strain VISA (MIC 39 μg/ml) followed by trans-p-coumaryl diacetate and 1′-hydroxychavicol acetate with MIC value of 156 μg/ml.

Conclusion

In conclusion, the observed antibacterial, anticandidal and antidermatophyte activity of the extracts and compounds obtained from the rhizome confirm the traditional use of Alpinia cochigera rhizome in the treatment of skin infection.     

In vitro estrogenic activity of Asplenium trichomanes L. extracts and isolated compounds

Ethnopharmacological relevance

Asplenium trichomanes was used as an expectorant, anti-cough remedy, laxative, emmenagogue, abortifacient and for irregular menses.

Aim of the study

To investigate the in vitro estrogenic activity of Asplenium trichomanes extracts and isolated compounds and their ability to activate ERα and ERβ.

Materials and methods

Leaves infusion (IF), decoction (DC) and methanol extract (ME) were prepared. MCF7/EREluc cell line which expresses endogenous ERα, and SK-NBE cells transiently transfected with the estrogen receptors (ERα and ERβ) were used for the estrogenic activity assays. Phytochemical investigations were performed (CC, HPLC, etc.) and structure of isolated compounds were achieved on the basis of 1D and 2D NMR techniques and HR-MS spectrometry.

Results

IF and ME were active in our MCF7 model; selectivity for the ERβ receptor was observed in the SK-NBE test. Two new phenol derivatives, 4-vinyl-phenol-1-O-[α-l-rhamno(1 → 6)-β-d-glucopyranosyde] (1) and kaempferol-3-O-α-[2′acetyl]-arabinofuranosyl-7-O-α-l-rhamnopyranoside (2) were isolated with six known compounds (3–8). Compounds 2–4, 7 and 8 showed selectivity for the activation of the ERβ receptor although with a moderate activity compared with 17-β-estradiol.

Conclusion

Further investigations about the estrogenic effects of this plant are needed but our data can, at least in part, explain some of its traditional use as emmeagogue.