In vitro antiplasmodial activity of Brazilian Cerrado plants used as traditional remedies

Twenty-seven species of native Brazilian Cerrado plants commonly used by traditional healers to treat malaria and other diseases were collected and 204 hexanic and ethanolic extracts were obtained by maceration. The antiplasmodial activity of the extracts was tested in vitro against a chloroquine resistant strain (FcB1) of Plasmodium falciparum, and cytotoxicity against the cell lines L-6 of rats and MRC-5 of human was evaluated. Thirty-two extracts showed significant inhibition rates of Plasmodium falciparum growth and of these six showed cytotoxicity against the cell lines. The strongest antiplasmodial activity was found for the hexanic extracts of Xylopia aromatica root wood (IC(50)=4.7 microg/ml), Xylopia emarginata root bark (IC(50)=4.9 microg/ml), Casearia sylvestris var. lingua leaves, stem wood and stem bark, and root wood and root bark (IC(50) values from 0.9 to 2.3 microg/ml), and Cupania vernalis leaves (IC(50)=0.9 microg/ml); and for the ethanolic extract of Aspidosperma macrocarpon root bark (IC(50)=4.9 microg/ml). However, the best selectivity towards Plasmodium falciparum was observed for the hexanic root bark extract of Matayba guianensis (IC(50) on Plasmodium falciparum=6.1 microg/ml, SI=16.4 for MRC-5) and the ethanolic root bark extract of Aspidosperma macrocarpon (IC(50) on Plasmodium falciparum=4.9 micro/ml, SI=16.2 for MRC-5).     

Antioxidant, anti-inflammatory and anticancer activities of methanolic extracts from Ledum groenlandicum Retzius

Labrador tea (Ledum groenlandicum Retzius) is an ericaceae widely distributed in North America. The leaves and twigs were used in Native American traditional medicine to treat several inflammatory pathologies such as asthma, rheumatisms and burns. Reactive oxygen species as well as reactive nitrogen species such as nitric oxide (NO) contribute significantly to these pathologies. In this study, the antioxidant, anti-inflammatory and anticancer activities of crude methanol extracts of leaves and twigs from Ledum groenlandicum were investigated. Both extracts showed a strong antioxidant activity using the ORAC method and a cell based-assay. Moreover, the twig and leaf extracts showed significant anti-inflammatory activity, inhibiting NO release, respectively, by 28 and 17% at 25 microg/ml in LPS-stimulated RAW 264.7 macrophages. In comparison, N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, reduced NO release by 24% at 25 microg/ml. The twig extract was also found to be active against DLD-1 colon carcinoma and A-549 lung carcinoma cells, with IC(50) values of 43+/-1 and 65+/-8 microg/ml, respectively. The bioguided study of the twig extract resulted in the isolation and identification of ursolic acid, a known triterpene. Ursolic acid was active against DLD-1 (IC(50): 9.3+/-0.3 microM) and A-549 (IC(50): 8.9+/-0.2 microM), suggesting it is, in part, responsible of the anticancer activity of the twig extract.     

Antiparasitic activity of some New Caledonian medicinal plants

Twenty-nine extracts of 18 medicinal plants used in New Caledonia by traditional healers to treat inflammation, fever and in cicatrizing remedies were evaluated in vitro against several parasites (Leishmania donovani, Trypanosoma brucei brucei, Trichomonas vaginalis and Caenorhabditis elegans). Among the selected plants, Scaevola balansae and Premna serratifolia L. were the most active against Leishmania donovani with IC(50) values between 5 and 10microg/ml. The almond and aril extracts from Myristica fatua had an IC(50) value of 0.5-5microg/ml against Trypanosoma brucei brucei. Only Scaevola balansae extract presented a weak activity against Trichomonas vaginalis. The almond extract from Myristica fatua presented significant activity against Caenorhabditis elegans (IC(50) value of 6.6+/-1.2microg/ml).     

Effect of Mexican medicinal plant used to treat trichomoniasis on Trichomonas vaginalis trophozoites

Crude methanolic extracts from 22 Mexican medicinal plants were screened for antitrichomonal activity against Trichomonas vaginalis, which is the etiological agent of trichomoniasis. Among the plants tested Carica papaya and Cocos nucifera showed the best antitrichomonal activity with IC(50) values of 5.6 and 5.8 microg/ml, respectively. The extracts of Bocconia frutescens, Geranium mexicanum, and Lygodium venustum showed moderate activity with IC(50) values ranging from 30.9 to 60.9 microg/ml. All the other plant extracts were inactive (IC(50)>100 microg/ml). All extracts tested were less active than metronidazole (IC(50) 0.037 microg/ml), an antiprotozoal drug used as positive control. The results of the antiprotozoal screening support the popular uses of five of the plants tested for the treatment of some urogenital tract disorders in Mexican traditional medicine. However, seeds of Carica papaya and aerial parts of Bocconia frutescens should be used in herbal medicine with care to avoid toxicity.     

In vitro antiprotozoal activities and cytotoxicity of some selected Cameroonian medicinal plants

Eight extracts from seven selected Cameroonian medicinal plants, traditionally used to treat malaria and other protozoal diseases, were tested in vitro for their antiprotozoal activities against Plasmodium falciparum K1 chloroquine-resistant strain, Leishmania donovani, Trypanosoma cruzi and Trypanosoma brucei rhodesiense, protozoa responsible for malaria, visceral leishmaniasis, Chagas disease and African trypanosomiasis, respectively. The most active extract against Plasmodium falciparum K1 strain and Trypanosoma brucei rhodesiense was the methanolic extract of Albizia zygia (Fabaceae) stem bark with IC(50) values of 1.0 microg/ml and 0.2 microg/ml, respectively. Five extracts showed IC(50) values below 5mug/ml against Leishmania donovani, with the methanolic seed extract of Harungana madagascarensis showing the highest activity, but only the methanolic extract of Albizia zygia showed activity against Trypanosoma cruzi. Cytotoxicity and selectivity indexes were estimated for the most active extracts. The best ratio of cytotoxicity to antiplasmodial activity (SI(a)=14) was established for the methanolic leaf extract of Symphonia globulifera (Clusiaceae), while the methanolic stem bark extract of Albizia zygia showed the best ratio of cytotoxicity to antitrypanosomal activity (SI(b)=22.5).     

Effects of compounds from Kaempferia parviflora on nitric oxide, prostaglandin E2 and tumor necrosis factor-alpha productions in RAW264.7 macrophage cells

Kaempferia parviflora Wall. ex Baker, is one of the plants in the Zingiberaceae family, locally known in Thai as kra-chai-dam. The rhizome of this plant has been used for treatment of gout, apthous ulcer and abscesses. Since K. parviflora rhizomes have long been used for treatment of inflammation and possessed marked nitric oxide (NO) inhibitory activity (IC(50)=7.8microg/ml), we thus investigated the inhibitory activity of compounds isolated from this plant against lipopolysaccharide (LPS)-induced NO release in RAW264.7 cells. From bioassay-guided fractionation of K. parviflora, seven methoxyflavones were isolated from the hexane fraction and were tested for their anti-inflammatory effects. Among the isolated compounds, compound 5 (5-hydroxy-3,7,3',4'-tetramethoxyflavone) exhibited the highest activity against NO release with an IC(50) value of 16.1microM, followed by 4 (IC(50)=24.5microM) and 3 (IC(50)=30.6microM). Compound 5 was also tested on LPS-induced prostaglandin E(2) (PGE(2)) and tumor necrosis factor-alpha (TNF-alpha) releases from RAW264.7 cells. It was revealed that 5 showed appreciable inhibitory effect on PGE(2) release (IC(50)=16.3microM), but inactive on TNF-alpha (IC(50)>100microM). These findings may support the use in Thai traditional medicine of K. parviflora for treatment of inflammatory-related diseases through the inhibition of NO and PGE(2) releases but partly due to that of TNF-alpha.     

Inhibition of pro-inflammatory mediators and tumor cell proliferation by Anisomeles indica extracts

Anisomeles indica (L.) Kuntze (Labiatae), is a traditional anti-inflammatory herb used in Taiwan. The aqueous and methanolic extracts of whole plants, leaves, flowers and stems; and chloroform and n-butanol fractions of methanol extract, from A. indica were investigated for their anti-inflammatory activity on murine peritoneal macrophages. In addition, the tumor cells proliferation inhibition activities of these extracts were also evaluated against a panel of tumor cell lines such as Colon 205, PC 3, HepG2 and MCF 7. Treatment with A. indica extracts did not reduce cell viability at any dose used. However, all the extracts significantly inhibited the enhanced production of NO radicals, and pro-inflammatory cytokines (TNF-alpha, and IL-12) induced by LPS/IFN-gamma in a dose-dependent manner. Furthermore, methanolic extracts of leaves and flowers significantly and dose-dependently arrest mitogen-stimulated spleen cells in G0/G1 stage, in addition to their cell proliferation inhibition against Colon 205, MCF 7 and PC 3 by 94, 82; 98, 71; 82, 98%, respectively, at 200 microg/mL concentration. This is the first report on A. indica extracts for their growth inhibitory activities, against inflammatory mediator production, and human tumor cell lines, colon, prostate, hepatoma and breast cells proliferation.     

Direct and indirect antimicrobial effects and antioxidant activity of Cordia gilletii De Wild (Boraginaceae)

Cordia gilletii De Wild (Boraginaceae) root bark is traditionally used in Democratic Republic of Congo (DRC) for the treatment of various disorders, including malaria, diarrhea, wounds and skin diseases; part of these activities may rely on antimicrobial and antioxidant properties. Successive extracts of root barks powder with n-hexane, dichloromethane, ethyl acetate, methanol and water were tested for antimicrobial activity, both direct and indirect (antibiotic resistance reversal), against 10 strains of bacteria and 1 strain of fungi by broth microdilution and agar diffusion methods. The eventual synergy between plant extracts and antibiotics was investigated by the determination of the fractional inhibitory concentration index (FIC index). The methanol extract showed direct antimicrobial activity against all tested microorganisms with minimum inhibitory concentrations (MIC) ranging between 125 and 1000 microg/ml, whereas the ethyl acetate and the dichloromethane extracts showed activity on four and three strains, respectively. 200 microg/ml of n-hexane and dichloromethane extracts decreased the MICs of penicillin and streptomycin 4-64-fold for methicillin-resistant Staphylococcus aureus. A synergistic effect was found between the methanol extract and tetracycline, whereas additive effects were observed for the other combinations tested. The methanol and dichloromethane extracts showed the greater antioxidant activity by scavenging the free radical DPPH with IC(50) values of 3.2 and 8.1 microg/ml, respectively. These results support the use of the plant in the treatment of infectious diseases and wounds; they warrant further studies as to the nature of active compounds.     

Antibacterial activities and cytotoxicity of terpenoids isolated from Spirostachys africana

Spirostachys africana Sond. stem bark is used traditionally for the treatment of diarrhoea and dysentery in Limpopo Province of South Africa. Bioassay-guided fractionation of ethanolic extract from bark of Spirostachys africana led to the isolation of four known compounds, two triterpenoids, compound 1 [d-Friedoolean-14-en-oic acid (3-acetyl aleuritolic acid)] and compound 2 (Lupeol), and two diterpenes, compound 3 [ent-2,6alpha-dihydroxy-norbeyer-1,4,15-trien-3-one (diosphenol 2)] and compound 4 (ent-3beta-hydroxy-beyer-15-ene-2-one). Isolated compounds were tested for antibacterial activity using micro-dilution method. Compound 1, exhibited minimum inhibitory concentration (MIC) of 50 microg/ml against Staphylococcus aureus, Salmonella typhy, Vibrio cholera, Escherichia coli and Shigella dysentery. Compound 2 was not active against all tested microorganisms at 200 microg/ml, which was the highest concentration tested. At this concentration, all four compounds were not active against Shigella sonnei. Cytotoxicity of ethanol crude extracts and isolated compounds from Spirostachys africana was determined using the sodium-2,3-bis-[2-methoxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) assay on Vero cells. Compounds 2 and 3, isolated from Spirostachys africana, had up to three times higher [50% inhibitory concentration (IC(50) values; 300.9 and 308.9 microg/ml)] than the ethanol crude extracts (102.8 microg/ml) suggesting higher toxicity of the crude extract as compared to these two compounds. In contrast, compounds 1 and 4 were not cytotoxic to Vero cell lines (African green monkey) in vitro at the concentrations tested (IC(50)>400 microg/ml). This is the first report on the antibacterial activity and cytotoxicity of purified compounds from Spirostachys africana.     

Antimalarial activity of some plants traditionally used in treatment of malaria in Kwale district of Kenya

Methanolic and water extracts of five medicinal plant species used for treatment of malaria in traditional/cultural health systems of Kwale people in Kenya were tested for antimalarial activity against Plasmodium falciparum and Plasmodium berghei, respectively and for their cytotoxic effects. The most active extracts (IC(50)<10 microg/ml) screened against chloroquine (CQ) sensitive (D6) and resistant (W2) P. falciparum clones, were the water and methanol extracts of Maytenus undata (Thunb.) Blakelock (Celasteraceae), methanol extracts of Flueggea virosa (Willd.) Voigt (Euphorbiaceae), Maytenus putterlickioides (Loes.) Excell and Mendoca (Celastraceae), and Warburgia stuhlmannii Engl. (Canellaceae). These extracts showed various cytotoxic levels on Vero E6 cells with the water extract of M. undata exhibiting least cytotoxicity. At least one of the extracts of the plant species exhibited a high chemo suppression of parasitaemia >70% in a murine model of P. berghei infected mice. These results indicate that there is potential for isolation of a lead compound from the extracts of the five plants. W. stuhlmannii and M. putterlickioides have not been reported before for antiplasmodial activity.     

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

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

Typhonium flagelliforme inhibits cancer cell growth in vitro and induces apoptosis: an evaluation by the bioactivity guided approach

AIM OF THE STUDY: Typhonium flagelliforme (Lodd.) Blume (Araceae) is a Malaysian plant used locally to combat cancer. In order to evaluate its antiproliferative activity in vitro and to possibly identify the active chemical constituents, a bioactivity guided study was conducted on the extracts of this plant. MATERIALS AND METHODS: The active extracts of Typhonium flagelliforme were fractionated by flash column chromatography and each fraction was evaluated for antiproliferative activity using MTT assay. The apoptotic effect of the active fraction was determined microscopically and by using TUNEL colorimetric assay. GC-MS and NMR were used to determine the chemical constituents of this active fraction. RESULTS: Several fractions of the hexane and dichloromethane extracts were found to inhibit the growth of NCI-H23 non-small cell lung carcinoma cell line significantly, with IC(50)<15 microg/ml. However, most of these active fractions were also found to inhibit the growth of non-tumorigenic BALB/c 3T3 mouse fibroblast cell line except for fraction 21 of the dichloromethane extract (D/F21). This particular fraction was not only less cytotoxic to the non-tumorigenic cells, where the IC(50) was 48.6 microg/ml compared to IC(50) 7.5 microg/ml for NCI-H23, but it was also found to induce apoptosis in the cancer cell line. GC-MS analysis revealed that D/F21 contains hexadecanoic acid, 1-hexadecene, phytol and a derivative of phytol. The presence of non-saturated fatty acids in this fraction was confirmed by nuclear magnetic resonance spectroscopy. CONCLUSIONS: D/F21 was found to be the active and cancer cell line specific fraction of Typhonium flagelliforme. Its major chemical constituents had been determined spectroscopically.     

Inhibition of lipoxygenases and cyclooxygenase-2 enzymes by extracts isolated from Bacopa monniera (L.) Wettst

AIM OF THE STUDY: Bacopa monniera Linn is described in the Ayurvedic Materia Medica, as a therapeutically useful herb for the treatment of inflammation. In the current study, we investigated the anti-inflammatory activity of methanolic extract of Bacopa monniera (BME). For some experiments EtOAc and bacoside fractions were prepared from BME. The effect of these extracts in modulating key mediators of inflammation was evaluated. MATERIALS AND METHODS: Carrageenan-induced rat paw edema, rat mononuclear cells and human whole blood assay were employed as in vivo and in vitro models. RESULTS: In carrageenan-induced rat paw edema, BME brought about 82% edema inhibition at a dose of 100mg/kg i.p. when compared to indomethacin (INDO) (3mg/kg) that showed 70% edema inhibition. BME also significantly inhibited 5-lipoxygenase (5-LOX), 15-LOX and cyclooxygenase-2 (COX-2) activities in rat monocytes in vivo. Among the fractions tested in vitro, EtOAc fraction possessed significant 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with IC(50) value of 30 microg/ml compared to butylated hydroxyl toluene (IC(50) = 13 microg/ml). This fraction also exerted significant hydroxyl radical scavenging activity with IC(50) value of 25 microg/ml in comparison with quercetin (IC(50) = 5 microg/ml). Inhibitory effects of EtOAc and bacoside fractions on LOX and COX activities in Ca-A23187 stimulated rat mononuclear cells were also assessed. 5-LOX IC(50) values were 25 microg/ml for EtOAc, 68 microg/ml for bacosides and 2 microg/ml for nordihydroguaiaretic acid (NDGA) where as COX-2 IC(50) values were 1.32 microg/ml for EtOAc, 1.19 microg/ml for bacoside fraction and 0.23 microg/ml for indomethacin. EtOAc and bacoside fractions also brought about significant decrease in TNF-alpha release ex vivo. CONCLUSION: Bacopa monniera possesses anti-inflammatory activity through inhibition of COX and LOX and downregulation of TNF-alpha.     

Isolation and identification of antiplasmodial sesquiterpene lactones from Oncosiphon piluliferum

Oncosiphon piluliferum (Asteraceae) is used traditionally to treat a variety of ailments, mainly fevers. This prompted the screening of this plant for antiplasmodial properties. The dichloromethane extract of the aerial parts of the plant showed activity in vitro against the chloroquine-sensitive (IC(50) 2.6microg/ml) and the chloroquine-resistant (IC(50) 3.1microg/ml) strains of Plasmodium falciparum. Through conventional chromatographic techniques and bioassay-guided fractionation, sesquiterpene lactones of the germacranolide and eudesmanolide type displaying significant in vitro antiplasmodial activity (IC(50) values ranging from 0.4 to 4.4microg/ml) were isolated and identified by spectroscopic data. In addition, the cytotoxic effects of the active compounds against Chinese Hamster Ovarian (CHO) cells were evaluated and the compounds were found to be toxic to mammalian cells at similar concentrations. Structure-activity relationships were assessed.     

Spasmolytic action of Lepechinia caulescens is through calcium channel blockade and NO release

The present study was undertaken to elucidate the mode of action of methanol extract from aerial parts of L. caulescens (TC-MELc) as spasmolytic agent on in vitro rat ileum test, and investigate the possible antibacterial activity of different extracts from the plant. TC-MELc induced a concentration-dependent (0.001 to 100microg/mL) antispasmodic effect on spontaneous contractions. TC-MELc also (IC50 11.2microg/mL) induced a marked depression on cumulative concentration-response curve for carbachol (Emax=2.3+/-0.3g vs. 0.66+/-0.1g) and serotonin (Emax=1.1+/-0.3g vs. -0.01+/-0.09g). Besides, extract decreased and displaced to the right KCl and CaCl2 concentration-response curves. Moreover, TC-MELc (11.2microg/mL) provoked a total relaxation when ileum strips were contracted with carbachol (1microM) in calcium-free Krebs solution. Pre-treatment with l-NAME (10microM) produced a significant change of the relaxant response and activity was markedly inhibited. Additionally, hexanic (HELc), dichloromethanic (DELc) and methanolic (MELc) extracts from aerial parts were studied to determine their antibacterial activity. DELc showed antibacterial activity on all bacterial strains assayed (相似文献   

Evaluation of the leishmanicidal activity of plants used by Peruvian Chayahuita ethnic group

AIM OF THE STUDY: A total of 27 ethanolic plant extracts from 27 species were screened for leishmanicidal activity in vitro against Leishmania amazonensis. Most of the selected species (19) are traditionally used by the Chayahuitas, an Amazonian Peruvian ethnic group, to treat skin affections and/or leishmaniasis. MATERIAL AND METHODS: A colorimetric method based on the reduction of tetrazolium salt (MTT) was used to measure the viability of Leishmania amazonensis promastigote and amastigote stages. RESULTS AND CONCLUSIONS: Only the leaves of two species of the Piperaceae family (Piper hispidum Sw., and Piper strigosum Trel.) showed good leishmanicidal activities (IC(50)<10 microg/ml against amastigotes). Roots of Tabernaemontana sananho Ruiz & Pav. (Apocynaceae), together with bark of Vismia tomentosa Ruiz & Pav. (Clusiaceae), fruits of Solanum straminifolium var straminifolium Jacq. (Solanaceae), and stems of Zamia lindenii Regel ex André (Cycadaceae) showed low activity against amastigote stage (IC(50) around 50 microg/ml). Of those only Tabernaemontana sananho displayed also good activity on promastigotes (IC(50)<10 microg/ml). Results are discussed herein, in relation with the traditional use of the plants and compared with other data from the relevant literature.     

Antiprotozoal activity of Senna racemosa

Methanol extracts of leaves, roots and bark of Senna racemosa (Mill.) H.S. Irwin & Barneby (syn. Cassia racemosa Mill.) were tested for antiprotozooal activity against Giardia intestinalis and Entamoeba histolytica. All of the tested extracts showed good activity against both protozoa species. Extracts from stem bark and leaves were most active, with an IC(50) of 2.10 microg/mL for Giardia intestinalis and 3.87 microg/mL for Entamoeba histolytica. Of the previously isolated compounds from Senna racemosa, the piperidine alkaloid cassine had greater activity against Giardia intestinalis with an IC(50) of 3.28 microg/mL and chrysophanol, a 1,8-dihydroxy-anthraquinone, was the most active agent against Entamoeba histolytica, with an IC(50) of 6.21 microg/mL.     

Anti-ulcer, anti-inflammatory and antioxidant activities of the n-butanol fraction from Pteleopsis suberosa stem bark

Pteleopsis suberosa Engl. et Diels (Combretaceae) is a tree distributed in many African countries. The decoction from the stem bark is orally administered for the treatment of gastric ulcers in traditional medicine. Previous pharmacological studies reported the anti-ulcer activity of extracts from P. suberosa stem bark. In the present study, the anti-ulcer and anti-inflammatory effects of the n-butanol fraction (RBuOH) obtained from a methanol extract of P. suberosa bark were investigated on ethanol-induced gastric ulcers in rats and carrageenan-induced paw oedema in mice. Misoprostol (0.50 mg/kg, p.o.) and indomethacin (8.00 mg/kg, p.o.) were used as positive controls for anti-ulcer and anti-inflammatory activities, respectively. Results showed that RBuOH treatment significantly reduced the incidence of gastric lesions (50 mg/kg, P<0.05; 100 and 200 mg/kg, P<0.01) and restored the decreased levels of total sulfhydryl groups (T-SH) and non-protein sulfhydryl groups (NP-SH) (50, 100 mg/kg, P<0.05; 200 mg/kg, P<0.01) in the stomach homogenate. Moreover, RBuOH treatment attenuated MDA levels as index of lipid peroxidation in gastric mucosa. Administration of RBuOH at the same dosage (50, 100 and 200 mg/kg) reduced significantly (P<0.01) carrageenan-induced paw oedema in dose-dependent manner (from 42.81% to 87.81% inhibition, 5h after carrageenan injection). The anti-inflammatory effect of RBuOH at 200 mg/kg was comparable with that of indomethacin. Finally, RBuOH proved to possess elevated free radical scavenger capacity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (IC(50) 23.48 microg/ml) which may contribute to the observed anti-ulcer and anti-inflammatory activities.     

Screening of selected indigenous plants of Cambodia for antiplasmodial activity

The in vitro antiplasmodial activity of 117 aqueous, methanol and dichloromethane extracts derived from different parts of 28 indigenous wild plant species was studied. These plants are commonly used in Cambodian traditional medicine. The plant extracts were tested for in vitro activity against a chloroquine resistant Plasmodium falciparum strain (W2). Nine extracts were moderately active with IC(50) values ranging between 5 and 10 microg/ml, 17 extracts were active with IC(50) values ranging between 1 and 5 microg/ml. These 26 extracts derived from eight plants belong to six families. The most active extracts were dichloromethane and came from Stephania rotunda and Brucea javanica with IC(50) values of 1 microg/ml and a selectivity index > or = 25. It is interesting to note that some aqueous extracts were as active as dichloromethane extracts especially aqueous extracts of Stephania rotunda, Brucea javanica, Phyllanthus urinaria and Eurycoma longifolia with IC(50) values of < or = 4 microg/ml. These results are in agreement with statements of healers on traditional uses of these plants for the treatment of malaria and/or fever. In this study, we report the antiplasmodial potential activity of eight plant species from Cambodia. Among them four are tested for the first time.