In Vitro Assessment of Plants Growing in Cuba Belonging to Solanaceae Family Against Leishmania amazonensis

In this study, an in vitro antileishmanial assessment of plant extracts from 12 genera and 46 species growing in Cuba belonging to Solanaceae family was performed. A total of 226 extracts were screened against promastigotes of Leishmania amazonensis, and cytotoxicity of active extracts [median inhibitory concentration (IC₅₀) promastigotes <100 µg/mL] was determined on peritoneal macrophage from BALB/c mice. Extracts that showed selective index >5 were then assayed against intracellular amastigote. Metabolomics analysis of promissory extracts was performed using chemical profile obtained by ultra performance liquid chromatography. Only 11 extracts (4.9%) from nine plants were selected as potentially actives: Brunfelsia cestroides A. Rich, Capsicum annuum L., Capsicum chinense Jacq., Cestrum nocturnum L., Nicotiana plumbaginifolia Viv., Solanum havanense Jacq., Solanum myriacanthum Dunal, Solanum nudum Dunal and Solanum seaforthianum And., with IC₅₀ < 50 µg/mL and selectivity index >5. Metabolomics analysis demonstrated significant differences in the chemical profiles with an average of 42.8 (range 31–88) compounds from m/z 104 to 1477, which demonstrated the complex mixture of compounds. In addition, no common markers among active extracts were identified. The results demonstrate the importance of the Solanaceae family to search new antileishmanial agents, particularly in unexplored species of this family. Copyright © 2016 John Wiley & Sons, Ltd.     

The potential antileishmanial activity of some Sudanese medicinal plants

A preliminary examination of the crude methanol extracts of eight plant species collected from Sudan, revealed that only three plant species had a considerable in vitro antileishmanial activity on Leishmania major promastigotes at a concentration < 0.5 µg/mL. The plants Azadirchta indica, Maytenus senegalensis and Eucalyptus globulus gave IC₅₀ values of 11.5, 55 and 78 µg/mL, respectively. Extracts of Pseudocedrela kotscifye and Balanites aegyptiaca had a moderate biological activity, whereas extracts of Sonchous cornatus, Khaya senegalensis and Tamarindus indica failed to exhibit any significant antileishmanial activity against L. major at concentrations <100 µg/mL. Liquid–liquid partitioning of the methanol extracts indicated that fractions of M. senegalensis in dichloromethane and ethyl acetate had the highest antileishmanial activity at 5 µg/mL; IC₅₀ values were 5.01 and 29.7 µg/mL, respectively. Preliminary phytochemical analysis of the dichloromethane fraction revealed terpenoids and traces of phenolic principles but no alkaloid, tannins or flavonoids were detected. As lymphocyte proliferation was inhibited by P. kotscifye and A. indica at higher concentrations (<50 µg/mL) in the presence of phytohaemagglutinin (PHA), M. senegalensis had no significant toxic effect whereas S. cornatus, T. indica and K. senegalensis had a stimulatory impact on lymphocyte cells. Copyright © 1998 John Wiley & Sons, Ltd.     

Evaluation of Turkish seaweeds for antiprotozoal, antimycobacterial and cytotoxic activities

As part of our continuing research on seaweeds, crude MeOH extracts of two green, three brown and six red algae collected from Marmara, Black, Aegean and Mediterranean Seas were screened. Four parasitic protozoa, i.e. Plasmodium falciparum, Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani and the tubercle bacillus Mycobacterium tuberculosis were used as test organisms for the in vitro assays. The selective toxicity of the extracts was also determined against mammalian L6 cells. All seaweed extracts were active against T. brucei rhodesiense; the Dasya pedicellata extract was the most potent (IC₅₀ value 0.37 µg/mL). The same extract also weakly inhibited the growth of T. cruzi (IC₅₀ 62.02 µg/mL). All seaweed extracts also showed leishmanicidal activity (IC₅₀ values 16.76–69.98 µg/mL). The majority of the extracts also exhibited antiplasmodial potential and the most potent extracts were those from D. pedicellata (IC₅₀ 0.38 µg/mL), Codium bursa (IC₅₀ 1.38 µg/mL) and Caulerpa rasemosa (IC₅₀ 3.12 µg/mL). One brown and two red algal extracts showed some weak activity against Mycobacterium tuberculosis (MIC values 125–256 µg/mL). Except for the extract of Dasya pedicellata, none of the extracts displayed any cytotoxicity. This is the second study investigating the antiprotozoal activities of Turkish marine algae and identifies Dasya pedicellata, an understudied algal species, as a candidate for further studies. Copyright © 2010 John Wiley & Sons, Ltd.     

Tanzanian medicinal plants used traditionally for the treatment of malaria: In vivo antimalarial and in vitro cytotoxic activities

Seventeen fractions of extracts obtained from 11 Tanzanian medicinal plants, which had previously been shown to possess a high antimalarial activity in vitro were submitted to the 4-day suppressive test in Plasmodium berghei-infected mice, and were investigated for cytotoxic activity in human carcinoma cell lines in vitro. Several fractions administered orally to the mice (500 mg/kg body weight/day) produced a significant reduction of parasitaemia. The most effective plant fractions investigated were those of the root and stem bark of Maytenus senegalensis (90% and 63% suppression of parasitaemia, respectively) and of the roots of Cissampelos mucronata (59% suppression). Highest cytotoxic activities were found with all fractions of Maytenus senegalensis (IC₅₀ 1 μg/mL) and with the PE fraction of the roots of Salacia madagascariensis (median IC₅₀=1.2 μg/mL for HT 29 and 2.3 μg/mL for KB).     

Antiviral activity of chilean medicinal plant extracts

Chilean flora is a potential source of bioactive compounds, including some with antiviral activity. Ninety aqueous and hydroaloholic extracts from 36 native and introduced plant species were screened for antiviral activity on herpes (HSV-1 and HSV-2) and HIV viruses. Furthermore, the samples were assayed for antimicrobial effect on pathogenic bacteria and a yeast. Plants were selected according to their indication of use for treating symptomatology of possible viral aetiology in Chilean folk medicine. The hydroaloholic extracts of Cassia stipulacea and Escallonia illintia exhibited detectable antiviral effects towards HSV-1 with IC₅₀ values of 80 and 40 μg crude extract/mL, respectively. Samples belonging to Aristotelia chilensis (IC₅₀ of 40 μg/mL), Drymis winteri (IC₅₀ values of 35 and 80μg/mL), Elytropus chilensis and Luma apiculata, with an IC₅₀ value of 100 μg/mL showed activity against HSV-2. None of the extracts showed activity against HIV at extract concentrations which were nontoxic for cells.     

Insecticidal activity of essential oils on Aedes aegypti larvae

The insecticidal activity of essential oils from 52 Bolivian plant species has been evaluated on Aedes aegypti larvae. The active components of essential oils showing an interesting larvicidal effect have been studied. The monoterpenes E-anethol and E-nerolidol were found to be the active principles of the most toxic essential oils. The lethal concentrations (LC₅₀ and LC₉₅) of some essential oils, E-anethol, E-nerolidol and a reference insecticide (Temephos) are given. © 1998 John Wiley & Sons, Ltd.     

Cytotoxic Properties of the Stem Bark of Citrus reticulata Blanco (Rutaceae)

The bioassay‐guided fractionation of the n‐hexane extract of Citrus reticulata Blanco (Rutaceae) stem bark yielded scoparone (1), xanthyletin (2), lupeol (3), β‐amyrin (4), stigmasterol (5), β‐sitosterol (6) and palmitic acid. The structures of these compounds were determined by comprehensive spectroscopic analyses, i.e., 1D and 2D NMR and EI‐MS, and by comparison with the reported data. Extracts, fractions and isolated compounds 1–6 were assessed for cytotoxicity by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐dphenyltetrazolium bromide (MTT) assay against three human cancer cell lines, i.e., human lung adenocarcinoma cell line A549, human breast adenocarcinoma cell line MCF7 and human Caucasian prostate adenocarcinoma cell line PC3. Significant activity of the n‐hexane and the dichloromethane extracts was observed against the breast cancer cell line MCF7 with IC₅₀s of 45.6 and 54.7 μg/mL, respectively. Moreover, the 70% ethyl acetate in n‐hexane chromatographic fraction showed significant activity displaying IC₅₀ values of 53.0, 52.4 and 49.1 μg/mL against the cancer cell lines A549, MCF7 and PC3, respectively. Encouragingly, an IC₅₀ of 510.0 μg/mL against the human normal prostate cell line PNT2 indicated very low toxicity and hence favourable selectivity indices for the 70% ethyl acetate in n‐hexane fraction in the range of 9.6–10.4 towards cell lines A549, MCF7 and PC3. Because compounds isolated from the above fraction only delivered IC₅₀ values in the range of 18.2–96.3, 9.2–34.1 and 7.5–97.2 μg/mL against A549, MCF7 and PC3 cell lines, respectively, synergistic action between compounds is suggested. Bioassay results valorize the anticancer effectivity of the stem bark of this plant in Cameroonian pharmacopoeia. Copyright © 2017 John Wiley & Sons, Ltd.     

Investigations into the antiadhesive activity of herbal extracts against Campylobacter jejuni

Campylobacter jejuni is one of the most common bacterial causes of diarrhoea in the industrialized world, being associated with the occurrence of Guillain‐Barré Syndrome, and inducing diseases partially through intestinal adherence. With increasing reports of C. jejuni drug resistance against standard antibiotics, investigations into antiadhesive agents for the prevention of bacterial infection are highly significant. Given the consumer‐driven development towards holistic and integrative healthcare, research into additional anti‐Campylobacter effects of herbal medicines that are already used for their beneficial effects on bowel and digestive functions is important. Twenty‐one herbal extracts were screened for antiadhesive activity against C. jejuni using modifications of previously published antiadhesion assays. Antiadhesion effects with IC₅₀ values <3 mg/mL were obtained for seven ethanol plant extracts, with Zingiber officinale (ginger), Capsicum annum (cayenne) and Glycyrrhiza glabra (licorice) displaying the highest antiadhesion activity against C. jejuni (IC₅₀: <0.1 mg/mL, 0.29 mg/mL and 0.65 mg/mL, respectively). Differences in antiadhesion activity were found for two different Echinacea species, with E. purpurea displaying significantly higher and dose dependent antiadhesion activity than E. angustifolia. No significant antiadhesion activity (IC₅₀ values >35 mg/mL) was found for Agrimonia eupatoria (agrimony), Andrographis paniculata (andrographis), Matricaria recutita (chamomile), Foeniculum vulgare (fennel), Filipendula ulmaria (meadowsweet) and Artemisia absinthium (wormwood) extracts. This study provides evidence for additional beneficial effects of marketed herbal medicines in gastrointestinal disorders. Copyright © 2011 John Wiley & Sons, Ltd.     

The antioxidant activity of Clitoria ternatea flower petal extracts and eye gel

Extracts of Clitoria ternatea (butterfly pea) flowers are used in Thailand as a component of cosmetics and the chemical composition of the flowers suggest that they may have antioxidant activity. In this study the potential antioxidant activity of C. ternatea extracts and an extract containing eye gel formulation was investigated. Aqueous extracts were shown to have stronger antioxidant activity (as measured by DPPH scavenging activity) than ethanol extracts (IC₅₀ values were 1 mg/mL and 4 mg/mL, respectively). Aqueous extracts incorporated in to an eye gel formulation were also shown to retain this activity, however, it was significantly less than a commercial antiwrinkle cream included for comparison. The total phenolic content was 1.9 mg/g extract as gallic acid equivalents. The data from this study support the use of C. ternatea extracts as antioxidant inclusions in cosmetic products. Copyright © 2009 John Wiley & Sons, Ltd.     

In vitro and in vivo antimalarial activity of cryptolepine,a plant-derived indoloquinoline

Cryptolepine is an indoloquinoline, high yields of which may be extracted from the roots of the West African shrub Cryptolepis sanguinolenta. The use of this plant as a traditional treatment for malaria is widespread in Ghana and is reported to be clinically effective. We have tested cryptolepine for in vitro antiplasmodial activity against the multidrug resistant (K1) strain of Plasmodium falciparum and found it to be highly active with an IC₅₀ value of 0.031±0.0085 (SE) μg/mL, equivalent to 0.134±0.037 μM (n = 3). In a 4-day suppression test there was, however, no significant reduction in parasitaemia in P. berghei-infected mice treated subcutaneously with cryptolepine (7–113 mg/kg/d×4), when compared with untreated controls. Like 9-aminoacridine, this compound appears to intercalate with DNA and this may explain the high degree of antimalarial activity demonstrated in vitro.     

In vitro Study of Five Herbs Used Against Microbial Infections in Burundi

The emergence of antimicrobial resistant infectious diseases remains a major threat to worldwide public health, in developed and in developing countries. Therefore, new antimicrobial agents acting by new mechanisms of action are urgently needed. As plants used in traditional medicine may help to overcome these problems, Justicia subsessilis, Platostoma rotundifolium, Pavetta ternifolia, Stomatanthes africanus, and Virectaria major (plants highly cited to be used against microbial infections in traditional Burundian medicine) were studied to assess their traditional use efficacy. We conducted a preliminary phytochemical screening of the extracts, as well as their direct and indirect (effect on antibiotic resistance) antibacterial activity on four bacterial strains (Staphylococcus sp. and Escherichia coli) by broth microdilution methods. All five medicinal plants investigated in this work were found to have direct antibacterial activity against all tested bacterial strains (minimum inhibitory concentration = 62.5–1000 μg/mL) that may support the use of these species in traditional Burundian medicine. Extracts (with no direct antibacterial activity), tested at 200 μg/mL, decreased the MIC values of β‐lactams and aminoglycoside antibiotics by a factor of 2 to 64‐fold. These interactions between plant extracts and antibiotics could open an avenue of research against antibiotic resistance. Copyright © 2017 John Wiley & Sons, Ltd.     

Antileishmanial activity of harmaline and other tryptamine derivatives

Tryptamine derivatives harmaline and α-ethyltryptamine were found to possess a novel antiparasitic action against human pathogen Leishmania mexicana amazonensis both in vitro and in vivo. In vitro, harmaline was the most potent compound tested, with an ED₅₀ of 99μ, whilst α-ethyltryptamine (ED₅₀ 149 μ) had the best therapeutic index (2). In vivo, α-ethyltryptamine was most effective when given orally (ED₅₀ 47 mg/kg), but was also effective when given topically. We suggest that further investigation of traditional plant drugs containing derivatives of β-carbolines and alkyltryptamines would provide a number of novel antiparasitic drugs.     

Compounds with tyrosinase inhibition, elastase inhibition and DPPH radical scavenging activities from the branches of Distylium racemosum Sieb. et Zucc

Twenty compounds were isolated from the ethanol extract of Distylium racemosum branches and their inhibitory activities on tyrosinase, elastase and free radicals evaluated. The isolated compounds were identified as dibenzofurans (1–4), abscisic acid (5), 6′‐O‐galloylsalidroside (6), catechin derivatives (7–11), gallic acid derivatives (12–14), tyrosol (15), flavonoids (16–18), lupeol (19) and 1,2,3,6‐tetragalloylglucose (20). For study of tyrosinase inhibition activities, when compared with arbutin (IC₅₀ 48.8 μg/mL), four compounds (8, 11, 13, 17) showed higher activities, with IC₅₀ values of 4.8, 30.2, 40.5 and 37.7 μg/mL, respectively. For the elastase inhibition test, dibenzofuran 1 showed greater activity than the positive control, oleanolic acid (IC₅₀ 9.7 μg/mL), with an IC₅₀ of 7.7 μg/mL. In the studies on DPPH radical scavenging activities, five compounds (11, 12, 13, 14, 15) showed higher activities than ascorbic acid (IC₅₀ 5.0 μg/mL), with IC₅₀ values of 4.6, 3.9, 2.9, 3.8 and 4.7 μg/mL, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

The Isolation of Antiprotozoal Compounds from Libyan Propolis

Propolis is increasingly being explored as a source of biologically active compounds. Until now, there has been no study of Libyan propolis. Two samples were collected in North East Libya and tested for their activity against Trypanosoma brucei. Extracts from both samples had quite high activity. One of the samples was fractionated and yielded a number of active fractions. Three of the active fractions contained single compounds, which were found to be 13‐epitorulosal, acetyl‐13‐epi‐cupressic acid and 13‐epi‐cupressic acid, which have been described before in Mediterranean propolis. Two of the compounds had a minimum inhibitory concentration value of 1.56 µg/mL against T. brucei. The active fractions were also tested against macrophages infected with Leishmania donovani, and again moderate to strong activity was observed with the compounds having IC₅₀ values in the range 5.1–21.9 µg/mL. Copyright © 2014 John Wiley & Sons, Ltd.     

Xanthine Oxidase Inhibitory Activity of Extracts Prepared from Polygonaceae Species

The xanthine oxidase (XO) inhibitory activity of aqueous and organic extracts of 27 selected species belonging in five genera (Fallopia, Oxyria, Persicaria, Polygonum and Rumex) of the family Polygonaceae occurring in the Carpathian Basin were tested in vitro. From different plant parts (aerial parts, leaves, flowers, fruits and roots), a total of 196 extracts were prepared by subsequent extraction with methanol and hot H₂O and solvent–solvent partition of the MeOH extract yielding n‐hexane, chloroform and 50% MeOH subextracts. It was found that the chloroform subextracts and/or the remaining 50% MeOH extracts of Fallopia species (F. bohemica, F. japonica and F. sachalinensis), Rumex species (R. acetosa, R. acetosella, R. alpinus, R. conglomeratus, R. crispus, R. hydrolapathus, R. pulcher, R. stenophyllus, R. thyrsiflorus, R. obtusifolius subsp. subalpinus, R. patientia) and Polygonum bistorta, Polygonum hydropiper, Polygonum lapathifolium and Polygonum viviparum demonstrated the highest XO inhibitory activity (>85% inhibition) at 400 µg/mL. The IC₅₀ values of the active extracts were also determined. On the basis of the results, these plants, and especially P. hydropiper and R. acetosella, are considered worthy of activity‐guided phytochemical investigations. Copyright © 2014 John Wiley & Sons, Ltd.     

Antioxidant activity of Osbeckia aspera

Plants of the Osbeckia family have been shown to possess hepatoprotective properties, which could be due to the presence of antioxidant compounds. The plant extract was shown to inhibit significantly in a dose-dependent manner, the activities of the DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical (EC₅₀ of 27.5 μg/mL), xanthine oxidase (EC₅₀ of 1.16 mg/mL) and demonstrate a scavenging effect on hydroxyl radical mediated damage to deoxyribose (EC₅₀ of 140 μg/mL). The plant extract possessed some prooxidant activity from the effect on bleomycin-induced DNA damage, but this was less than that shown by comparable concentrations of (+)-catechin or silymarin. © 1998 John Wiley & Sons, Ltd.     

In vitro anti‐adhesive activity of green tea extract against pathogen adhesion

Camellia sinensis polysaccharide has been reported to possess anti‐adhesive activity against pathogens. The present study was designed to investigate whether hot water extracts obtained from green tea leaves might inhibit pathogen adhesion to human or mouse cell lines. Green tea extract‐4 (CSI‐4) with the maximum yield of 4% (w/v) is composed of a major proportion of carbohydrates containing 40% uronic acids, but lack of catechins. It showed strong inhibitory activities against hemagglutination mediated by pathogens Helicobacter pylori, Propionibacterium acnes and Staphylococcus aureus with the minimum inhibitory concentrations of 0.01‐0.5 mg/mL. CSI‐4 further demonstrated an inhibitory effect on the adhesion of these pathogens to host cell lines with the IC₅₀ values (50% inhibition of adhesion) of 0.14–2.3 mg/mL. It exhibited the highest activity against P. acnes, but no inhibitory effects were observed against Lactobacillus acidophilus, Bifidobacterium bifidum, Escherichia coli, or Staphylococcus epidermidis. Our results suggest that CSI‐4 may exert a selective anti‐adhesive effect against certain pathogenic bacteria with no adverse effects against beneficial or commensal bacteria. Copyright © 2008 John Wiley & Sons, Ltd.     

Antimalarial activity and cytotoxicity of Ficus pyrifolia and Rhus (=Baronia) taratana leaf extracts

Ethanolic leaf extracts of Ficus pyrifolia (Moraceae) and Rhus(= Baronia) taratana (Anacardiaccae), said to possess antimalarial effects in traditional herbal medicines, were tested against Plasmodium falciparum in vitro using an isotropic semi-microtest and in vivo in the 4 day suppressive test in Plasmodium berghei infected mice. Although the in vitro test showed moderate or low activity (IC₅₀ = 18 μg/mL and 80 μg/mL, respectively), the in vivo bioassays demonstrated significant activity with 67%, 52% and 48% suppression of parasitaemia with 80, 320, 2.5 mg/kg day^?1 of Ficus pyrifolia, Rhus taratana and chloroquine, respectively. The two plant extracts showed low cytotoxicity.     

Antimalarial Activity of Alkaloids from Pogonopus tubulosus

The antimalarial activity of the Bolivian medicinal plant Pogonopus tubulosus (D.C.) Schumann was evaluated by in vitro testing on trophozoite stages of resistant and sensitive strains of Plasmodium falciparum and by in vivo tests on P. berghei and P. vinckei petteri in mice. The bark of this medicinal plant yielded three alkaloids: tubulosine, psychotrine, cephaeline. Tubulosine showed an interesting activity in vitro with an IC₅₀ of 0.006 μg/mL against the sensitive strain of P. falciparum and an IC₅₀ of 0.011 μg/mL against the resistant strain of P. falciparum . This compound had good in vivo antimalarial activity with an ED₅₀ of 0.05 mg/kg/day on P. vinckei petteri strain and an ED₅₀ of 0.45 mg/kg/day on P. berghei.     

Antiproliferative activity of Hungarian Asteraceae species against human cancer cell lines. Part II

The antiproliferative activities of aqueous and organic extracts prepared from 26 Hungarian species of the tribes Cynereae and Lactuceae (Asteraceae) were tested in vitro against HeLa (cervix epithelial adenocarcinoma), A431 (skin epidermoid carcinoma) and MCF7 (breast epithelial adenocarcinoma) cells by using the MTT assay. Of the tested 200 extracts of different plant parts obtained with n‐hexane, chloroform, 50% methanol and water, 16 extracts displayed noteworthy cell growth inhibitory activity (>50% inhibition at a concentration of 10 µg/mL). The IC₅₀ values of these extracts were determined, and their direct cytotoxic effects were measured. High differences between the antiproliferative and cytotoxic activities, demonstrating a real cell proliferation inhibitory activity rather than direct killing effects, were found for some Centaurea, Cirsium, Cichorium, Lactuca, Onopordum and Scorsonera extracts. Copyright © 2009 John Wiley & Sons, Ltd.