Antimalarial and antiplasmodial activity of husk extract and fractions of Zea mays

Context: Zea mays L. (Poacae) husk decoctions are traditionally used in the treatment of malaria by various tribes in Nigeria.

Objective: To assess the antimalarial and antiplasmodial potentials of the husk extract and fractions on malaria parasites using in vivo and in vitro models.

Materials and methods: The ethanol husk extract and fractions (187–748?mg/kg, p.o.) of Zea mays were investigated for antimalarial activity against Plasmodium berghei using rodent (mice) malaria models and in vitro activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using the SRBR green assay method. Median lethal dose and cytotoxic activities against HeLa and HEKS cells were also carried out. The GCMS analysis of the most active fraction was carried out.

Results: The husk extract (187–748?mg/kg, p.o.) with LD₅₀ of 1874.83?mg/kg was found to exert significant (p?P. berghei infection in suppressive, prophylactive and curative tests. The crude extract and fractions also exerted prominent activity against both chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC₅₀ values of 9.31?±?0.46?μg/mL (Pf 3D7) and 3.69?±?0.66?μg/mL (Pf INDO). The crude extract and fractions were not cytotoxic to the two cell lines tested with IC₅₀ values of?>100?μg/mL against both HeLa and HEKS cell lines.

Discussion and conclusion: These results suggest that the husk extract/fractions of Zea mays possesses antimalarial and antiplasmodial activities and these justify its use in ethnomedicine to treat malaria infections.     

Antimalarial drug discovery: screening of Brazilian medicinal plants and purified compounds

Background: Malaria is the most important parasitic disease and its control depends on specific chemotherapy, now complicated by Plasmodium falciparum that has become resistant to most commonly available antimalarials. Treatment of the disease requires quinine or drug combinations of artemisinin derivatives and other antimalarials. Further drug resistance is expected. New active compounds need to be discovered. Objective/method: To find new antimalarials from medicinal and randomly collected plants, crude extracts are screened against P. falciparum in cultures and in malaria animal models, following bioassays of purified fractions, and cytotoxicity tests. Conclusion: For antimalarial research, screening medicinal plants is more efficient than screening randomly chosen plants. Biomonitored fractionation allows selection of new active molecules identified as potential antimalarials in multidisciplinary projects in Brazil; no new molecule is available for human testing. The advantages of projects based on ethnopharmacology are discussed.     

In vitro antiplasmodial activity of Tithonia diversifolia and identification of its main active constituent: tagitinin C

The antimalarial properties of Tithonia diversifolia, an Asteraceae traditionally used to treat malaria, were investigated in vitro against three strains of Plasmodium falciparum. The ether extract from aerial parts of the plant collected in S?o Tomé e Príncipe, demonstrated good antiplasmodial activity (IC 50 on FCA strain: 0.75 microg/ml). A bioassay guided fractionation of this extract led to the isolation of the known sesquiterpene lactone tagitinin C as an active component against Plasmodium (IC 50 on FCA strain: 0.33 microg/ml), but also possessing cytotoxic properties (IC 50 on HTC-116 cells: 0.706 microg/ml).     

Antimalarial,antiplasmodial and analgesic activities of root extract of Alchornea laxiflora

Context: Alchornea laxiflora (Benth.) Pax. &; Hoffman (Euphorbiaceae) root decoctions are traditionally used in the treatment of malaria and pain in Nigeria.

Objective: To assess the antimalarial, antiplasmodial and analgesic potentials of root extract and fractions against malarial infections and chemically-induced pains.

Material and methods: The root extract and fractions of Alchornea laxiflora were investigated for antimalarial activity against Plasmodium berghei infection in mice, antiplasmodial activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of Plasmodium falciparum using SYBR green assay method and analgesic activity against experimentally-induced pain models. Acute toxicity study of the extract, cytotoxic activity against HeLa cells and GCMS analysis of the active fraction were carried out.

Results: The root extract (75–225?mg/kg, p.o.) with LD₅₀ of 748.33?mg/kg exerted significant (p?P. berghei infection in suppressive, prophylactive and curative tests. The root extract and fractions also exerted moderate activity against chloroquine sensitive (Pf 3D7) and resistant (Pf INDO) strains of P. falciparum with the ethyl acetate fraction exerting the highest activity with IC₅₀ value of 38.44?±?0.89?μg/mL (Pf 3D7) and 40.17?±?0.78?μg/mL (Pf INDO). The crude extract was not cytotoxic to HeLa cells with LC₅₀ value >100?μg/mL. The crude extract and ethyl acetate fraction exerted significant (p?Discussion and conclusions: These results suggest that the root extract/fractions of A. laxiflora possess antimalarial, antiplasmodial and analgesic potentials and these justify its use in ethnomedicine to treat malaria and pain.     

Studies on the antiplasmodial properties of some South African medicinal plants used as antimalarial remedies in Zulu folk medicine

The parasite lactate dehydrogenase (pLDH) assay method, a recently developed in vitro enzymatic method for evaluating antimalarial compounds, was used to examine the antiplasmodial activities of the aqueous leaf, stem-bark and fruit extracts of some plants used for the treatment and/or prophylaxis of malaria in KwaZulu-Natal province of South Africa. The in vitro antiplasmodial assay was carried out using a chloroquine-sensitive strain of malarial parasite, Plasmodium falciparum D10. A preliminary phytochemical analysis of the plant extracts was carried out using UV spectral analysis and thin-layer chromatography (TLC) to separate the chemical constituents of the extracts. Their chemical components were subsequently identified by treating the TLC plates with various spray reagents. Of the 14 plant extracts investigated, only 10 were found to have IC50 values of 10-50 micrograms/ml. The two most active extracts were Psidium guajava stem-bark extract and Vangueria infausta leaf extract, both of which showed IC50 values of 10-20 micrograms/ml. Phytochemical analysis of these two active plant extracts revealed the presence of anthraquinones, flavonoids, seccoirridoids and terpenoids.     

Screening for Cytotoxic and Antimalarial Activities in Desert Plants of the Negev and Bedouin Market Plant Products

Aqueous extracts of 66 desert plants of the Negev and Beer Sheva Bedouin market plant products were tested for antitumor, antimalarial (protozoa) and growth inhibition of wheat-rootlet activities. Pteranthus dichotomus, Gypsophila arabica, Achillea fragrantissima, Urginea maritima, and Solanum elaeagnifolium exhibited strong cytotoxicity (above 97%) against cultured melanoma cell lines. Mesembryanthemum nodiflorum, Gypsophila arabica, Hammada scoparia, Trigonella foenum-graecum and Peganum harmala had more than 80% inhibition both in rootlet and melanoma assays. Hammada scoparia, Pulicaria crispa, Centaurea eryngioides, Echinops polyceras, Ephedra aphylla, Teucrium polium, Phlomis brachyodon, Urginea maritima, Ochradenus baccatus, Verbascum fruiticulosum, Corchorus olitorius, and Peganum harmala demonstrated strong growth inhibition (above 96%) of the malaria parasite Plasmodium falciparum. The plants that were positive for antimelanoma and antimalarial activities have been under further investigation for the isolation and characterization of the anticancer and antimalarial compounds.     

Evaluation of the mutagenicity of antimalarial products isolated from Solanum nudum (Solanaceae)

Diosgenone is a major component of the hexane extract from the plant Solanum nudum (Solanaceae). The products from degraded and acetylated diosgenone that showed in vitro antimalarial activity against the FCB-2 strain of Plasmodium falciparum and methanol, dichloromethane and ethereal extracts of Solanum nudum were tested for their mutagenic activity using the Ames test with the TA-97a, TA-98, TA-100 and TA-102 strains of Salmonella typhimurium. These compounds were not mutagenic at the tested concentrations.     

Antimalarial activity of herbal extracts used in traditional medicine in Korea

Aqueous extracts of 6 traditional Korean medicines used to treat malaria were tested in vitro for their antimalarial activity against Plasmodium falciparum. The EC50 values for the herbal extracts were in the range 1.4-8.1 microg/ml. Significant antimalarial activity was observed with Coptis japonica (EC50=1.4 microg/ml), but it demonstrated no selective toxicity (selectivity=1). In contrast, Kalopanax pictus showed antimalarial activity (EC50=4.6 microg/ml) and higher selective toxicity (>4). This indicated that K. pictus may be potent for a new antimalarial agent.     

Antimalarial Activity of Some Kenyan Medicinal Plants

This paper describes the in vitro antimalarial activity of eight species of plants popularly used traditionally to treat malaria in Kenya. Organic and aqueous extracts from different parts of the plants were tested. Generally, a stronger antimalarial activity was observed in the organic extracts. The most active extracts were of Vernonia brachycalyx O. Hoffm. Schreber. (Compositae) leaves which showed an IC 50 of 6.6 µg/ml for methylene chloride: ethyl acetate (1:1) extracts, while the aqueous and more polar methanolic extracts gave IC 50 values of 29.6 and 30 µg/ml, respectively. The findings of this study support the use of this plant as a traditional remedy for malaria. The rest of the plants tested gave IC 50 values between 30–100 µg/ml.     

Antiplasmodial activity of extracts of 25 cyanobacterial species from coastal regions of Tamil Nadu

Context: Marine cyanobacteria offer considerable potential to isolate new antimalarials to meet a pressing need of our times.

Objective: To explore the antiplasmodial properties of marine cyanobacteria.

Materials and methods: Cyanobacterial samples collected from the coastal regions of Tamil Nadu were identified using light microscopy, and the strains were cultivated in ASN-III medium. Organic extracts (0–100?µg?mL^?1) of 25 in vitro mass-cultivated cyanobacteria, prepared using methanol: chloroform mixture (1:1?v/v) were evaluated for their antiplasmodial activity against chloroquine-sensitive and -resistant strains of Plasmodium falciparum by fluorescence-based SYBR Green I assay where chloroquine was used as a control. To detect the toxic effects of cyanobacterial extracts against red blood cells, the invasion, maturation, and growth rate of malarial parasites in cyanobacterial extracts pre-treated versus untreated erythrocytes were quantified microscopically. Mammalian cell line (HeLa) was used to determine cyanobacterial extract toxicity using the MTT assay.

Results: The extracts of Lyngbya aestuarii Liebm. ex Gomont CNP 1005 (C12) Oscillatoria boryana BDU 91451 (C22) and Oscillatoria boryana Bory ex Gomont BDU 141071 (C18) showed promising antiplasmodial activity (IC₅₀?=?18, 18, and 51?μg?mL^?1 respectively) against Pf3D7. Pretreatment of red blood cells with IC₁₀₀ of C12, C18, and C22 (40, 100, and 40?µgmL^?1, respectively) did not significantly influence the invasion, maturation, and growth rate of malarial parasites in comparison with untreated RBC controls suggesting a lack of toxicity to host cells. MTT assay based IC₅₀ (>200?μg?mL^?1) of these extracts against HeLa cell line also indicates their high selectivity against the malaria parasite.

Discussion and conclusion: These exploratory studies suggest the possibilities of development of new antimalarial compounds from marine cyanobacteria.     

Antiprotozoal screening of the Cuban native plant Scutellaria havanensis

Context: Scutellaria havanensis Jacq. (Lamiaceae) is a native medicinal herb with a history of use in Cuba.

Objective: This study screens the antiprotozoal activity of S. havanensis.

Materials and methods: Chloroform and methanol extracts from leaves and stems were evaluated in vitro at doses between 0.015 and 200?μg/mL against protozoan parasites: Plasmodium berghei, Trichomonas vaginalis and Leishmania amazonensis. Chloroform and methanol extracts were characterized by GC/MS. Cytotoxicity against mouse peritoneal macrophages was tested in parallel.

Results: Scutellaria havanensis extracts exhibited IC₅₀ values between 7.7 and 32.2?μg/mL against trophozoites of P. berghei and T. vaginalis; while the extracts were inactive against L. amazonensis promastigotes. Trichomonicidal activity of methanol extract exhibited the best selectivity but chloroform extract showed the highest antiplasmodial, trichomonicidal and cytotoxic activity. The majority of compounds in the chloroform extract were hydroxy and/or methoxyflavones (77.96%), in particular, wogonin (48.27%). In methanol extract, wogonin (5.89%) was detected. Trichomonicidal effect of wogonin was moderate (IC_50?=_?56?μM) and unspecific with respect to macrophages (SI?=?2). On the contrary, antiplasmodial activity of wogonin were particularly active (IC_50?=_?15?μM) demonstrating a higher selectivity index (SI?=?7.4).

Conclusions: Wogonin is an active principle compound of the chloroform extract of S. havanensis against P. berghei and T. vaginalis trophozoites, whereas the methanol extract of S. havanensis should be investigated more deeply as a trichomonicide. Our findings suggest that wogonin is potentially useful for the development of antimalarial alternative treatments.     

In vitro antimalarial activity of a series of cationic 2,2'-bipyridyl- and 1,10-phenanthrolineplatinum(II) benzoylthiourea complexes

We have synthesized a series of novel 2,2'-bipyridyl and 1,10-phenanthroline benzoylthiourea complexes of platinum(II) with various substituents on the bipyridyl and phenanthroline ligands. All of these square-planar mixed-ligand cationic complexes were found to form moderately strong complexes with ferriprotoporphyrin IX in 40% aqueous DMSO (log K ranging from 4.81 to 6.24). The complexes also all inhibit beta-hematin (synthetic hemozoin or malaria pigment) formation in acetate solution. Four of the compounds were found to exhibit in vitro antimalarial activity, with (N-benzoyl-N',N'-di(2-hydroxyethyl)thioureato)(4,4'-di-tert-butyl-2,2'-bipyridyl)platinum(II) chloride being particularly active. These active complexes exhibited equally strong activity against both the D10 chloroquine sensitive and K1 chloroquine resistant strains of malaria parasite. Cytotoxicity testing of the four most active compounds shows that they exhibit selective activity against malaria parasites with selectivity indices greater than 85. These compounds represent a new family of potential antimalarials.     

In Vitro Antimalarial Activity of Brucea javanica against Multi-Drug Resistant Plasmodium falciparum.

The medicinal plant, BRUCEA JAVANICA (L.) Merr. (Simaroubaceae) was examined for antimalarial properties. Among different crude solvent extracts of the fruit, the chloroform extract was shown to have the most potent IN VITRO antimalarial activity. Three active compounds were isolated and purified from the chloroform extract. These compounds were confirmed as bruceine A, bruceine B hydrate and bruceine C by UV, IR, NMR and mass spectra. When tested IN VITRO against multi-drug resistant isolates of P. FALCIPARUM bruceine A and bruceine B hydrate were similar in activity (ID50 of 8.66 and 8.15 ng/ml) whereas bruceine C had an ID50 of 1.95 ng/ml. These compounds were comparable in IN VITRO activity to the new antimalarial drug, mefloquine (ID50 of 6.26 ng/ml).     

Multiple Antiviral Activities of Endemic Medicinal Plants Used by Berber Peoples of Morocco

We investigated the antiviral activities of methanol extracts of 75 Moroccan plants (64 genera of 35 families), used traditionally to treat diseases that could be caused by viruses and microbes. The plants included many endemic to Morocco and used by Berber as well as Arab peoples. They were evaluated against three mammalian viruses: herpes simplex virus, Sindbis virus and poliovirus, at non-cytotoxic concentrations. Five extracts were very active against the three viruses, 16 were active against two viruses, and 24 were only active against one virus. Thirty-two extracts showed light enhanced and two showed light-dependent activities. Punica granatum extract, which was the most active, inhibited all three viruses at a concentration of only 1.5 µg/ml, although these activities were not light enhanced. The extracts of Acacia gummifera, Juglans regia, Thymus maroccanus, Lawsonia inermis, Pinus halepensis, and Rosa canina inhibited Sindbis virus at a minimum concentration of 1.5 µg/ml. Thymus maroccanus and Rosa canina activities were light enhanced. Pistacia lentiscus and Thymus maroccanus were very active against herpes simplex virus. The extracts most active against poliovirus were those from Pinus halepensis and Punica granatum. These were active at minimum concentrations of 6.5 µg/ml, but were not light enhanced. These results indicate that some of these plants are potential potent medicines against infectious diseases caused by viruses. Their discriminatory effect against specific microorganisms suggests the presence of different chemical compounds. Light is a determining factor in the activity of photosensitizers and should be definitely taken into account in this kind of test.     

Garcinia mangostana: a source of potential anti-cancer lead compounds against CEM-SS cell line

Our current interest in searching for natural anti-cancer lead compounds from plants has led us to the discovery that the stem and roots of Garcinia mangostana can be a source of such compounds. The stem furnished 2,8-dihydroxy-6-methoxy-5-(3-methylbut-2-enyl)-xanthone (1), which is a new xanthone. Meanwhile, the root bark of the plant furnished six xanthones, namely alpha-mangostin (2), beta-mangostin (3), gamma-mangostin (4), garcinone D (5), mangostanol (6), and gartanin (7). The hexane and chloroform extracts of the root bark of G. mangostana as well as the hexane extract of the stem bark were found to be active against the CEM-SS cell line. gamma-Mangostin (4) showed good activity with a very low IC(50) value of 4.7 microg/ml, while alpha-mangostin (2), mangostanol (6), and garcinone D (5) showed significant activities with IC(50) values of 5.5, 9.6, and 3.2 microg/ml, respectively. This is the first report on the cytotoxicity of the extracts of the stem and root bark of G. mangostana and of alpha-mangostin, mangostanol, and garcinone D against the CEM-SS cell line.     

Antimicrobial activity of the crude ethanol extract from Pimenta pseudocaryophyllus

The antimicrobial activity of the crude ethanol extract from Pimenta pseudocaryophyllus (Gomes) L. R. Landrum (Myrtaceae), collected at two locations in Brazil, was investigated. Leaf samples were collected in April 2005 and in September 2005, both in Brasília, DF, Brazil, and in July 2000 in São Gonçalo do Abaeté, MG, Brazil. They were dried, crushed and used to obtain three crude ethanol extracts. The agar diffusion test was used for antimicrobial activity screening and the agar dilution method for determining the minimal inhibitory concentration (MIC). In assay conditions, extracts I, II and III demonstrated antimicrobial activity against Gram-positive Staphylococcus aureus, Micrococcus luteus, M. roseus, Bacillus cereus, B. atrophaeus, and B. stearothermophilus (MIC 0.39062 to 12.5?mg/mL, MIC 0.78125 to 1.5625?mg/mL and MIC 0.39062 to 1.5625?mg/mL, respectively), against Gram-negative Pseudomonas aeruginosa (MIC 0.39062 to 3.125?mg/mL, MIC 1.5625?mg/mL and MIC 0.78125 to 1.5625?mg/mL, respectively), against clinical isolates of Pseudomonas stutzeri (MIC 0.39062 to 0.78125?mg/mL, MIC 0.78125 to 1.5625?mg/mL, MIC 0.78125 to 1.5625?mg/mL, respectively) and also against Candida albicans fungi (MIC 0.19531?mg/mL for the extracts I, II and III). This study showed that the antimicrobial activity of P. pseudocaryophyllus might be considered sufficient to encourage further studies to isolate and identify its active principles. Pharmacological and toxicological studies are also necessary, followed by studies regarding the culturing and managing processes of this vegetable.     

Evaluation of mutagenic activity of several antimalarial extracts from Eupatorium inulaefolium

Eupatorium inulaefolium is used as an antimalarial agent by traditional healers of the Tumaco region (Nari?o-Colombia). Several extracts of this plant have been tested by our laboratory and in vitro antimalarial activity against the FCB-2 strain of Plasmodium falciparum has been confirmed. For this reason, the mutagenic effect of the methanol, dichloromethane, and hexane extracts of Eupatorium inulaefolium (number 83377 university of Antioquia herbarium) were evaluated using the Ames test. None of the extracts evaluated had mutagenic effects on TA-98 or TA-100 strains of Salmonella typhimurium.     

Antimalarial Ethnobotany: In Vitro. Antiplasmodial Activity of Seven Plants Identified in the Nigerian Middle Belt

Abstract

Seven methanol extracts of seven plants from seven plant families were screened for antimalarial properties. The plants were identified and selected from Gboko and Kastina-Ala local government areas in the Tivland ethnobotany in the Middle Belt Zone of Nigeria. Methanol plant extracts were evaluated for in vitro. antimalarial properties using the lactate dehydrogenase technique, with a multiresistant strain of Plasmodium falciparum. K1. Quantification of activity was by estimation of the concentration of extracts that inhibited 50% growth of parasite (IC₅₀) in µg/ml. Of the seven plants screened, Erythrina senegalensis. DC (Leguminosae), Pericopsis elata. Harms (Papilionaceae), and Bridelia micrantha. Benth (Fabaceae) had IC₅₀ values of 99.7, 124.8, and 158.7?µg/ml, respectively. Nauclea latifolia. SM (Rubiaceae) extract exhibited the least activity in the assay with an IC₅₀ value of 478.9?µg/ml.     

In vivo antimalarial activity of ginseng extracts

Context: Novel antimalarial agents are in demand due to the emergence of multidrug resistant strains. Ginseng, a medicinal plant with antiparasitic activity, contains components that can be used to treat the tropical disease malaria.

Objective: Ginsenosides and polysaccharides are active components of ginseng. This study aimed to elucidate the ability of these compounds to inhibit the replication of Plasmodium yoelii in an attempt to determine whether the medicinal uses of ginseng are supported by pharmacological effects. New antimalarial compounds may be developed from ginsenosides and water-soluble ginseng polysaccharides (WGP).

Materials and methods: Ginsenosides and ginseng polysaccharides were prepared from ginseng. Antimalarial activities were examined by 4-day tests and repository tests. Macrophage phagocytosis was tested in normal and malaria-bearing mice.

Results: Ginseng polysaccharides could inhibit residual malaria infection. After a 6-day treatment, the parasitemia reductions of WGP and acidic ginseng polysaccharide (WGPA) were 55.66% and 64.73% at 200?mg/kg/day, respectively. Ginsenosides showed significant antimalarial activity on early infection. Protopanaxadiol-type ginsenosides caused 70.97% chemosuppression at 50?mg/kg/day, higher than 52.8% of total ginsenosides at the same dose.

Discussion and conclusion: Protopanaxadiol-type ginsenosides have remarkably suppressive activity during early infection, while acidic ginseng polysaccharides have significant prophylactic activity against malaria by stimulating the immune system. We propose that the activity of ginsenosides is dependent upon non-specific carbohydrate interactions and that the activity of ginseng polysaccharides is due to immunological modulation. Ginsenosides and ginseng polysaccharides might have a potential application in antimalarial treatments.     

Studies on cytotoxic, hydroxyl radical scavenging and topoisomerase inhibitory activities of extracts of Tabernaemontana divaricata (L.) R.Br. ex Roem. and Schult

In the present investigation, the cytotoxic, hydroxyl radical scavenging and topoisomerase inhibition activities of Tabernaemontana divaricata (Apocynaceae) were evaluated. The extracts from leaves of the plant were prepared with different solvents viz. chloroform, methanol, ethyl acetate and hexane. In, in vitro cytotoxicity assay, with cell lines viz HCT-15 (Colon), HT-29 (Colon), 502713 (Colon), MCF-7 (Breast), PC- 3 (Prostrate), it was observed that the ethyl acetate extract was effective against only one colon cell line (502713) at the lowest dose i.e. 10 micro g/ml, whereas the chloroform extract was effective against all the three colon cancer cell lines, at 30 microg/ ml. In order to evaluate the mechanism of cytotoxicity of these extracts, they were assessed for their ability to scavenge hydroxyl radicals in plasmid nicking assay with pBR322. It was observed that all the extracts effectively inhibited the unwinding of supercoiled DNA except hexane extract, which showed the least effect. Since the expression of topo enzymes is linked with cell proliferation so the extracts were also checked for topo I and topo II inhibitory activities. It was noticed that ethyl acetate extract selectively showed inhibition of topo II in topoisomerase II relaxation assay.