Cryptoccocal meningitis in Yaoundé (Cameroon) HIV infected patients: Diagnosis, frequency and Cryptococcus neoformans isolates susceptibility study to fluconazole.

Cryptococcal meningitis is a mycosis encountered especially in patients with Acquired Immunodeficiency Syndrome and is fatal in the absence of treatment. Information on epidemiology, diagnosis and susceptibility profile to antifungal drugs, are scarce in Cameroon. Authors evaluated the diagnosis possibilities of the cryptococcal meningitis in Cameroon, and studied the antifungal susceptibility of isolated strains to fluconazole, used as first line treatment of the disease in Cameroon. Between December 2009 and July 2011, 146 cerebrospinal fluids obtained from HIV patients with suspicion of meningitis were analysed. The diagnosis procedure involved macroscopic and cyto-chemical analysis, India ink test, culture on Sabouraud chloramphenicol medium and antigen latex agglutination test. Antifungal susceptibility testing of isolated strains to fluconazole was done by the E-test(®) method. The diagnosis of cryptococcal meningitis gave 28.08% positive cases. Among these patients, 80% were at stages III and IV and 20% at stage I of the HIV infection, according to the WHO previous classification. Cyto-chemical analysis showed current findings in the case of cryptococcal meningitis. India ink test and latex agglutination test exhibited very high sensitivity and specificity (>94%). Fluconazole antifungal susceptibility testing gave MICs lower than 32µg/mL to 92.7% of isolated strains and MICs greater than this value to 7.3% of isolates. These results showed that cryptococcal meningitis remains a real problem among HIV infected patients in Yaoundé. The emergence of fluconazole reduced susceptibility strains is worrying. Nevertheless, efficacy of rapid detection tests is interesting because this will help in rapid diagnosis and treatment of patients.

Studies on medicinal plants of Ivory Coast: investigation of Sida acuta for in vitro antiplasmodial activities and identification of an active constituent.

Sida acuta Burm. (Malvaceae) originating from Ivory Coast was selected after an ethnobotanical survey: traditional healers of malaria commonly used this plant for the treatment. Extracts were tested on two strains of Plasmodium falciparum: FcM29-Cameroon (chloroquine-resistant strain) and a Nigerian chloroquine-sensitive strain. Extracts were obtained by preparing decoction in water of the powdered plant, the technique used by most of the traditional healers. An ethanol extract was then made and tested. The IC50 values obtained for these extracts ranged from 3.9 to -5.4 microg/ml. Purification of this active fraction led to the identification of cryptolepine as the active antiplasmodial constituent of the plant.

N'Dribala (Cochlospermum planchonii) versus chloroquine for treatment of uncomplicated Plasmodium falciparum malaria.

The aim of this work was to assess the efficacy of oral N'Dribala (tuberous roots decoction of Cochlospermum planchonii Hook) treatment versus chloroquine in non-severe malaria. The study included 85 patients with uncomplicated Plasmodium falciparum infection in Banfora, Burkina Faso. Forty-six patients that received N'Dribala beverage were compared to 21 patients treated with chloroquine. All patients were monitored with clinical examination and a parasitemia control by Giemsa-stained thick films. N'Dribala appeared safe and statistically as efficient as chloroquine for the treatment of uncomplicated Plasmodium falciparum malaria. At day 5 (D5), 57% of chloroquine-treated and 52% of N'Dribala-treated patients were cured with no detectable parasitemia (parasite density (Pd): 0) and more than 90% of whole patients were asymptomatic. N'Dribala is easily available in this country, cheap, without significant side effects and efficient with a clearly demonstrated activity on Plasmodium falciparum blood stages. This study enhances the traditional use of the Cochlospermum planchonii as alternative therapy for treatment of non-severe malaria.

In vitro antiplasmodial activity of extracts of Alchornea cordifolia and identification of an active constituent: ellagic acid.

Extracts of leaves of Alchornea cordifolia were studied for their antiplasmodial activities. Chloroformic and ether extracts were found to be inactive while the ethanolic extract exhibited mild in vitro activity against Plasmodium falciparum. Fractionation of this extract led us to isolate ellagic acid as the active constituent of the extract with IC(50) in the range of 0.2-0.5 microM. Cytotoxicity of ethanolic fraction and ellagic acid was also estimated on human fibroblasts cells (IC(50) on Hela cells = 7.3 microM at 24 h for ellagic acid).

Antiplasmodial activity of aspidosperma indole alkaloids.

The antiplasmodial activity of twelve alkaloids with an aspidospermane skeleton was estimated in vitro on chloroquine-resistant and sensitive strains of Plasmodium falciparum. Seven tetracyclic alkaloids possessing a free ethyl chain such aspidospermine, showed IC50 after incubation for 72 h between 3.2 and 15.4 microM. Moreover, four pentacyclic alkaloids with ethyl chain included in a tetrahydrofuran, such haplocine, showed a reduced activity, with IC50, after 72 h, between 22.6 and 52.6 microM. According to these results, a chloroquine-potentiating experiment was also performed with two of the most active compounds. Isobolograms were obtained and demonstrated a synergic effect of N-formyl-aspidospermidine and aspidospermine when associated with chloroquine. The cytotoxicity and the selectivity index of some alkaloids were also estimated.

Actividad antipacudica y potenciación de lacloroquina con alcaloides aporfinicos in vitro / In vitro antimalarial activity and chloroquine potentiating action of aporphine alkaloids

Pregunta de investigación: ¿Los alcaloides aporfínicos tiene una actividad intrinseca antipalúdica, pueden potencializar la acitivad de la cloroquina y revertir la resitencia de Plasmodium falciparum?. OBjetivos: Determinar la actividad antipaludica intrinseca de 12 alcaloides aporfínicos, Determinar el nivel de su efecto, establecer si tiene efecto y de maduracion o ponteciación, sinergismo aditivo o de antagonismo con la cloroquina, Determinar qué alcaloide pueden provocar reversión de la resistencia a la cloroquina, Estudiar un posible mecanismo de acción. Lugar:IINSAD, IBBA. Métodos: Cultivo de estadios eritrocitarios de Plasmodium falciparum, evaluación de la actividad antipalúdica in vitro de los alcaloides aporfinicos usando varios métodos. Resutlados: Los alcaloides evaluados son menos acativos que la cloroquia sola, todos los alcaloides mostraron un claro efecto acumulativo, especialmente Glaucina fumarato, Los alcaloides asimilobina, isoboldina HCI, coridina y actinodafnia conbinados con lacloroquina mostraron un efecto antagónico hacia esta droga, losalcaloides nuciferina HCI, pachyconfina, cassiticina, presentan un efecto de potenciación a la cloroquina. Glaucina fumarato, lautotetanina e isocorytuberina mostraron un sinergismo aditivo a la cloroquina, Nuceferina HCI revierte la resisstencia de la cloroquina a 0.5ug/ml, pachyconfina a la concentraion de 2 ug/ml y cassyticina a 1 ug/ml, se evidenció que los alcaloides aorfinicos no perturban el mecanismo de transporte creado por los parásitos intraeritrocitarios. Conclusión: Los 12 alcaloides aporfinicos, no presentan una actividad mayor que la cloroquina, pero nuciferina HCI, pachyconfina y cassyticina convinados con esta 4 aminoquinolina, pueden potencializar su actividad y revertir la resitencia de cepas cloroquina-resistentes, la modalidad de acción de estos alcaloides es de tipo acumulativo y no perturban el mecanismo de transporte creado por los parásitos intraeritrocitarios.

Antiplasmodial activity of plant extracts used in west African traditional medicine.

Five plants originating from Ivory Coast were selected after an ethnobotanical survey, Alchornea cordifolia, Mitragyna inermis, Nauclea diderrichii, Pterocarpus santalinoides, and Terminalia glaucescens. Traditional healers for the treatment of malaria commonly used these plants. Extracts of these plants were tested on three strains of Plasmodium falciparum, FcB1-Colombia and FcM29-Cameroon (chloroquine-resistant strains) and a Nigerian chloroquine-sensitive strain. Extracts were obtained by preparing decoction in water of the powdered plant, the technique used by most of the traditional healers. A radioactive micromethod allowed the evaluation of the in vitro activity of the extracts on P. falciparum. Concentrations inhibiting 50% of the parasite growth (IC(50)) ranged from 2.34 to more than 500 microg/ml according to the plant. For the most active plants (A. cordifolia and T. glaucescens) ethanol and pentane extracts were made and tested. The IC(50) values obtained for these extracts ranged from 0.35 to 43.40 microg/ml. The stage specificity of the ethanol extracts of A. cordifolia and T. glaucescens and pentane extract of T. glaucescens on the parasite erythrocytic cycle were determined. The ethanol extract of T. glaucescens showed its highest activity at the transition from the trophozoite to the schizont stages. Cytotoxicity was estimated on human fibroblasts (HeLa) cells and a cytotoxicity/antiplasmodial index was calculated, it ranged between 5 and 21, and the best antiplasmodial extract (T. glaucescens ethanol extract) had the higher index (>20).

Anti-Toxoplasma activity of vegetal extracts used in West African traditional medicine.

Both Toxoplasma gondii and Plasmodium are Apicomplexan protozoa that share common metabolic pathways and potential drug targets. The objective of this study was to examine the anti-Toxoplasma activity of nine West African plants with known activity against P. falciparum. The extracts were obtained from parts of plant commonly used, by most traditional healers, in the form of infusion or as water decoction. The in vitro activity of plant extracts on T. gondii was assessed on MRC5 tissue cultures and was quantified by enzyme-linked immunoassay. Aqueous extracts from Vernonia colorata were found to be inhibitory for Toxoplasma growth at concentrations > 10 mg/L, with an IC50 of 16.3 mg/L. A ten-fold gain in activity was obtained when organic solvents such as dichloromethane, acetone or ethanol were used to extract V. colorata's active principles. These extracts were inhibitory at concentrations as low as 1 mg/L, with IC50 of 1.7, 2.6 and 2.9 mg/L for dichloromethane, acetone and ethanol extracts respectively. These results indicate a promising source of new anti-Toxoplasma drugs from V. colorata and African medicinal plants.

New potential antimalarial agents: synthesis and biological activities of original diaza-analogs of phenanthrene.

Several diaza-analogs of phenanthrene derived from 3-amino, 5-amino, 6-amino, 8-aminoquinolines, and 5-aminoisoquinoline were prepared to evaluate their antiplasmodial activities. All compounds showed mild to good activitiy in vitro, both on a Nigerian chloroquino-sensitive strain and on the chloroquino-resistant FcB1-Columbia and FcM29 strains. The position of the intracyclic nitrogen atom is shown to be crucial for the activities (best results are obtained with a 1,10-phenanthroline skeleton). In regard to the particular properties of this structure (metalloprotease inhibition activitiy by chelating divalent metal ions), the potential chelating site of the molecule was blocked. In this case, the biological activity of the compound was greatly enhanced, showing that the mechanism of action of such a compound is probably not correlated to metalloprotease inhibition activity.

Antimalarial activity and cytotoxicity of (-)-roemrefidine isolated from the stem bark of Sparattanthelium amazonum.

(-)-Roemrefidine, an aporphine alkaloid isolated from Sparattanthelium amazonum Martius (Hernandiaceae) a vine from Bolivia, has been found to be active against both resistant and sensitive strains of Plasmodium falciparum in vitro and against P. berghei in mice. The compound demonstrated no cytotoxic activity against three cell lines (KB, HEp-2 and HeLa).

In vitro antimalarial activity and cytotoxicity of cochlospermum tinctorium and C. planchonii leaf extracts and essential oils.

The antimalarial and toxicological properties of Cochlospermum tinctorium and C. planchonii extracts and essential oils prepared from their leaves were studied. The oil components were extracted by hydrodistillation of the plant leaves and characterized by gas chromatography and mass spectrometry. Crude extracts and oils were tested for in vitro antimalarial activity on Plasmodium falciparum. The IC50 were evaluated after 24 and 72 h contact between the oils and the parasite culture, and ranged from 22 to 500 micrograms/ml. C. planchonii leaf oil yielded the best antimalarial effect (IC50: 22-35 micrograms/ml), while the most potent effect from crude leaf extracts was induced by C. tinctorium. The cytotoxicity of the leaf crude extracts and oils was assessed on the K562 cell line and showed IC50 values ranging between 33 and 2000 micrograms/ml.

[Genotype, serotype and sensitivity to fluconazole of Candida albicans strains isolated from HIV-positive patients]. / Génotype, sérotype et sensibilité au fluconazole de souches de Candida albicans isolées chez des patients VIH positif.

Genotype, serotype and susceptibility in vitro to fluconazole of 104 C. albicans strains isolated from HIV+ patients were studied. The possible correlations between genotype analysed by multilocus enzyme electrophoresis (MLEE) and phenotype of medical relevance (serotype and susceptibility to fluconazole) of Candida albicans isolated from these patients treated with fluconazole were evaluated by factorial correspondence analysis. No correlation was observed between genotype and in vitro or clinical response to fluconazole. In counterpart, serotype B C. albicans was associated with some multilocus genotypic patterns.

Oropharyngeal candidiasis in AIDS patients from Abidjan (Ivory Coast): antifungal susceptibilities and multilocus enzyme electrophoresis analysis of Candida albicans isolates.

Multilocus enzyme electrophoresis (MEE) and in vitro antifungal susceptibility testing were used to investigate the Candida albicans strain diversity in twenty nine AIDS patients from Abidjan (Ivory Coast). All patients were monitored for a first episode of oropharyngeal candidiasis and were randomly clustered into three groups of therapy: ketoconazole, amphotericin B or nystatin. Oral swabs were collected before every treatment, 14 and 30 days after the initiation of the therapy; a total of 67 isolates were investigated. No resistant or less susceptible isolate to any antifungal agent was found despite the emergence of clinical relapses, mainly for patients treated with nystatin or amphotericin B. The MEE analysis revealed 27 different electrophoretic types (ETs). Genetic distances between ETs were statistically analyzed and represented on a dendrogram. The 27 ETs clustered into three groups; in each group, ETs represented variants of the same strain. A segregation of the C. albicans isolates seemed to be as a function of the serotype.

In vitro antiplasmodial activity of stem and root extracts of Nauclea latifolia S.M. (Rubiaceae).

Aqueous extracts from Nauclea latifolia S.M. (Rubiaceae), a plant commonly used in Ivory Coast by traditional healers for the treatment of malaria, were tested on two strains of Plasmodium faliparum: FcB1-Colombia (chloroquine-resistant) and a Nigerian strain (chloroquine-sensitive). The extracts were obtained from stems and roots of the plant in two forms, infusion and decoction, both methods used by most traditional healers. The in vitro activity of N. latifolia extracts on P. falciparum was assessed both visually and by a radioactive method. The visual analysis allowed determination of the time of extract action on the erythrocytic cycle, as well as the parasitic stage of most inhibitory effect. Similar results were obtained applying fresh, frozen or lyophilized extracts. The IC50 values determined were within the range already reported for other antimalarial plants such as Azadirachta indica A. Juss (Meliaceae) or Artemisia annua L. (Asteraceae). Aqueous extracts of N. latifolia inhibited P. falciparum (FcB1 strain) mainly at the end of the erythrocytic cycle (32nd to 48th hour).

In vitro antimalarial activity of penduline, a bisbenzylisoquinoline from Isopyrum thalictroides.

Two bisbenzylisoquinolines, tetrandrine and penduline, were purified from Isopyrum thalictroides. When tested for antimalarial activity in vitro, penduline was efficient at concentrations fivefold lower than those of tetrandrine. In highly synchronized parasite cultures, penduline mostly interfered between the 8th and the 32nd hours of the parasite cycle.

In vitro antimalarial activity of vegetal extracts used in West African traditional medicine.

Among strategies for the development of new antimalarials, a study of plants traditionally used in Africa against malaria has been pursued. Extracts obtained from the plants Azadirachta indica, Cinnamonum camphora, Lippia multiflora, Vernonia colorata, Guiera senegalensis, Combretum micranthum, and Ximenia americana, commonly used in Cote d'Ivoire by native healers for the treatment of malaria, were tested on two strains of Plasmodium falciparum: FcB1-Colombia (chloroquine-resistant) and F32-Tanzania (chloroquine-sensitive). Extracts were obtained after infusion and decoction, both techniques being used by most native healers. The antimalarial activities of the extracts were tested first by parasite 3H-hypoxanthine incorporation and second by visual evaluation of the activities of plant extracts on thin blood smears, which also permitted the determination of parasitic stages and parasite alteration. Among the seven plants tested, some had an apparent inhibitory effect on P. falciparum growth in vitro, while other seemed to be less efficient.

Composition and antimalarial activity in vitro of volatile components of Lippia multiflora.

The essential oil of Lippia multiflora was prepared by hydrodistillation of leaves and stalks and characterized by GC and mass spectroscopy. The oil was tested for antimalarial activity on in vitro cultures of Plasmodium falciparum (FcB1-Columbia chloroquine-resistant strain and F32-Tanzania chloroquine-sensitive strain). The dilutions inhibiting the in vitro growth of the parasite by 50% 24 and 72 hr after administration of the essential oil to the parasite culture were 1/12,000 and 1/21,000, respectively. When tested on a highly synchronized culture, the essential oil inhibited growth mostly at the trophozoite-schizont step, indicating a potential effect on the first nuclear division of the parasite.

Antimalarial activity in vitro of Cochlospermum tinctorium tubercle extracts.

Resistance of Plasmodium falciparum to current antimalarial compounds has drastically increased during the last few years and is now a major public health problem. We have studied plants traditionally used in Africa against malaria. Extracts of the tubercles of Cochlospermum tinctorium A. Rich, commonly used in Burkina Faso, were tested in vitro on 2 strains of P. falciparum, one (FcB1-Colombia) chloroquine resistant and the other (F32-Tanzania) chloroquine sensitive. Extracts were obtained by infusion and decoction. The 50% inhibitory concentrations (IC50) were determined by measuring [3H]hypoxanthine incorporation and also by microscopical examination which permitted the determination of parasite stages. We obtained similar results with fresh extracts, frozen extracts, and lyophilized extracts of C. tinctorum. IC50 values were of the order of 1-2 micrograms/mL, about one-tenth of those reported for extracts of neem leaves (Azadirachta indica) and about half the values reported for Artemisia annua extracts.