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1.
PLoS Med ; 18(6): e1003669, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34129601

RESUMEN

BACKGROUND: In Phase II/III randomized controlled clinical trials for the treatment of acute uncomplicated malaria, pyronaridine-artesunate demonstrated high efficacy and a safety profile consistent with that of comparators, except that asymptomatic, mainly mild-to-moderate transient increases in liver aminotransferases were reported for some patients. Hepatic safety, tolerability, and effectiveness have not been previously assessed under real-world conditions in Africa. METHODS AND FINDINGS: This single-arm, open-label, cohort event monitoring study was conducted at 6 health centers in Cameroon, Democratic Republic of Congo, Gabon, Ivory Coast, and Republic of Congo between June 2017 and April 2019. The trial protocol as closely as possible resembled real-world clinical practice for the treatment of malaria at the centers. Eligible patients were adults or children of either sex, weighing at least 5 kg, with acute uncomplicated malaria who did not have contraindications for pyronaridine-artesunate treatment as per the summary of product characteristics. Patients received fixed-dose pyronaridine-artesunate once daily for 3 days, dosed by body weight, without regard to food intake. A tablet formulation was used in adults and adolescents and a pediatric granule formulation in children and infants under 20 kg body weight. The primary outcome was the hepatic event incidence, defined as the appearance of the clinical signs and symptoms of hepatotoxicity confirmed by a >2× rise in alanine aminotransferase/aspartate aminotransferase (ALT/AST) versus baseline in patients with baseline ALT/AST >2× the upper limit of normal (ULN). As a secondary outcome, this was assessed in patients with ALT/AST >2× ULN prior to treatment versus a matched cohort of patients with normal baseline ALT/AST. The safety population comprised 7,154 patients, of mean age 13.9 years (standard deviation (SD) 14.6), around half of whom were male (3,569 [49.9%]). Patients experienced 8,560 malaria episodes; 158 occurred in patients with baseline ALT/AST elevations >2×ULN. No protocol-defined hepatic events occurred following pyronaridine-artesunate treatment of malaria patients with or without baseline hepatic dysfunction. Thus, no cohort comparison could be undertaken. Also, as postbaseline clinical chemistry was only performed where clinically indicated, postbaseline ALT/AST levels were not systematically assessed for all patients. Adverse events of any cause occurred in 20.8% (1,490/7,154) of patients, most frequently pyrexia (5.1% [366/7,154]) and vomiting (4.2% [303/7,154]). Adjusting for Plasmodium falciparum reinfection, clinical effectiveness at day 28 was 98.6% ([7,369/7,746] 95% confidence interval (CI) 98.3 to 98.9) in the per-protocol population. There was no indication that comorbidities or malnutrition adversely affected outcomes. The key study limitation was that postbaseline clinical biochemistry was only evaluated when clinically indicated. CONCLUSIONS: Pyronaridine-artesunate had good tolerability and effectiveness in a representative African population under conditions similar to everyday clinical practice. These findings support pyronaridine-artesunate as an operationally useful addition to the management of acute uncomplicated malaria. TRIAL REGISTRATION: ClinicalTrials.gov NCT03201770.


Asunto(s)
Antimaláricos/uso terapéutico , Artesunato/uso terapéutico , Malaria/tratamiento farmacológico , Naftiridinas/uso terapéutico , Adolescente , Adulto , África , Antimaláricos/efectos adversos , Artesunato/efectos adversos , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Niño , Preescolar , Combinación de Medicamentos , Femenino , Humanos , Lactante , Recién Nacido , Pruebas de Función Hepática , Malaria/diagnóstico , Malaria/parasitología , Masculino , Naftiridinas/efectos adversos , Seguridad del Paciente , Vigilancia de Productos Comercializados , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
2.
Trop Med Int Health ; 26(5): 530-534, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33529447

RESUMEN

OBJECTIVE: To characterise the factors associated with HIV treatment failure (HIVTF) from reported pharmacovigilance data in Africa. MATERIALS AND METHODS: This is an observational pharmacovigilance analysis of the safety data of HIVTF available in the WHO International Pharmacovigilance database 'VigiBase® '. We used the Standardised MedDRA Queries (SMQ) to identify all the terms corresponding to HIVTF. To identify all relevant molecules and classes of antiretroviral therapy, we used the anatomic, therapeutic, and chemical classification. We presented results as a percentage or an adjusted Reporting Odds Ratio (aROR) with a 95% confidence interval (95% CI). RESULTS: HIVTF was more reported in Africa compared with the rest of the world with 19.1% (18.1%-20.1%) corresponding to 1206 of all 6304 HIVTF reports. Among all the 37 WHO country members in Africa, South Africa was the main source of origin for these HIVTF reports with 86.8% (84.9%-88.7%). Compared to adults, children and adolescents were the most population groups affected by HIVTF, aROR = 2.7, (95% CI) 1.7-4.2 and aROR = 7.9, (95% CI) 4.5-13.9, respectively. CONCLUSION: South Africa was the leading country of the reporting of HIVTF in Africa. The proportion of HIVTF was higher in both HIV-infected children and adolescents than in adults. There is a need for the improvement of medical care for children and adolescents with HIV infection in Africa.


Asunto(s)
Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Farmacovigilancia , Adolescente , África , Niño , Preescolar , Bases de Datos Factuales , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos , Insuficiencia del Tratamiento , Organización Mundial de la Salud
3.
Acta Crystallogr C ; 69(Pt 12): 1557-62, 2013 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-24311512

RESUMEN

Physalis angulata L., an annual herb from the Solanaceae family, is widely used in popular medicine in tropical countries to treat a variety of diseases. Two products, (X) and (Y), were isolated from a crude CH2Cl2 extract of dried Congolese Physalis angulata L. plants and crystallized from acetone for structure elucidation. Compound (X) corresponds to a physalin B dimer acetone solvate hydrate (2C28H30O9·C3H6O·0.22H2O), while compound (Y) crystallizes as a mixed crystal containing two physalin B molecules which overlap with 5ß,6ß-epoxyphysalin B, also known as physalin F, and one acetone molecule in the asymmetric unit (1.332C28H30O9·0.668C28H30O10·C3H6O). Antiplasmodial activity, cytotoxic activity and selectivity indices were determined for crude extracts and the two isolated products (X) and (Y).


Asunto(s)
Physalis/química , Secoesteroides/química , Secoesteroides/aislamiento & purificación , Secoesteroides/farmacología , Cristalografía por Rayos X , Enlace de Hidrógeno , Estructura Molecular
4.
Planta Med ; 78(9): 853-60, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22538476

RESUMEN

According to the promising results of the Phase I and Phase IIA clinical trials with the herbal medicinal product PR 259 CT1 consisting of an 80 % ethanolic extract of the stem bark of Nauclea pobeguinii containing 5.6 % strictosamide, a Phase IIB study was conducted as a single blind prospective trial in 65 patients with proven Plasmodium falciparum malaria to evaluate the effectiveness and safety of this herbal drug. The study was carried out simultaneously using an artesunate-amodiaquine combination (Coarsucam®) as a positive control. This combination is the standard first-line treatment for uncomplicated malaria recommended by the National Programme of Malaria Control in the Democratic Republic of Congo (DR Congo). With regard to PR 259 CT1, patients were treated with a drug regimen of two 500-mg capsules three times daily for three days in the inpatient clinic, followed by out-patient treatment of one 500-mg capsule three times daily during the next four days; the positive control group received two tablets containing 100 mg artesunate and 270 mg amodiaquine (fixed-dose) once daily during three consecutive days. Antimalarial responses were evaluated according to the WHO 2003 guideline for a 14-day test. The results from the physical and laboratory examinations did not show any significant changes in values of vital signs, ECG, biochemical, and haematological parameters. The study showed a significant decreased parasitaemia in patients treated with PR 29 CT1 and artesunate-amodiaquine with adequate clinical parasitological responses (APCR) at day 14 of 87.9 and 96.9 %, respectively. The former product was better tolerated than the latter since more side effects were observed for the artesunate-amodiaquine combination. These results indicated that PR 259 CT1 can be considered as a promising candidate for the development of a herbal medicine for the treatment of uncomplicated falciparum malaria.


Asunto(s)
Antimaláricos/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Extractos Vegetales/uso terapéutico , Rubiaceae , Adolescente , Adulto , Amodiaquina , Antimaláricos/efectos adversos , Artemisininas , Combinación de Medicamentos , Femenino , Humanos , Malaria Falciparum/parasitología , Masculino , Medicinas Tradicionales Africanas , Corteza de la Planta/química , Estudios Prospectivos , Método Simple Ciego , Resultado del Tratamiento , Adulto Joven
5.
Planta Med ; 78(3): 211-8, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22095262

RESUMEN

The aim of this phase IIA clinical trial was to assess the efficacy of an 80 % ethanolic quantified extract (containing 5.6 % strictosamide as the putative active constituent) from Nauclea pobeguinii stem bark denoted as PR 259 CT1 in a small group of adult patients diagnosed with uncomplicated falciparum malaria. Results obtained from a phase I clinical trial on healthy male volunteers indicated that the oral administration during meals of two 500 mg capsules three times daily (each eight hours) during seven days was well tolerated and showed only mild and self-resolving adverse effects. This PR 259 CT1 drug regimen was obtained by mathematical conversion of animal doses obtained in several in vivo studies in mice to human equivalent doses as in falciparum malaria patients. The phase IIA study was an open cohort study in eleven appraisable adult patients suffering from proven Plasmodium falciparum malaria. The study was specifically designed to assess the efficacy of PR 259 CT1 administered with a dose regimen of two 500 mg capsules three times daily for three days, followed by outpatient treatment of one 500 mg capsule three times daily for the next four days, in order to prove that this therapeutic dose, which was calculated from animal doses, was effective to treat adult malaria patients and consequently useful for a future Phase IIB clinical trial. This study would then substitute a dose-escalating trial, which in general is used to find the appropriate dose for clinical studies. The phase IIA clinical trial was carried out according to the WHO 2003 14-day test, and the results revealed that all eleven patients were completely cleared of parasitemia and fever on days 3, 7, and 14 except for one patient, who experienced a recurrence of parasitemia at days 7 until 14. Besides this adequate clinical and parasitological response (ACPR), this trial also demonstrated that PR 259 CT1 was well tolerated with only mild and self-resolving adverse effects including fatigue and headache, which were in accordance with those found in the phase I clinical trial. Moreover, all symptoms progressively disappeared, and no symptoms were observed on day 14. Although the number of patients included in this study was rather limited, the statistical analysis nevertheless suggested the efficacy and tolerability of PR 259 CT1, which indicated that this herbal medicinal product might be considered as a putative candidate for a large scale clinical trial.


Asunto(s)
Antimaláricos/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Fitoterapia/métodos , Extractos Vegetales/uso terapéutico , Rubiaceae/química , Alcaloides de la Vinca/uso terapéutico , Administración Oral , Adolescente , Adulto , Antimaláricos/efectos adversos , Femenino , Humanos , Masculino , Corteza de la Planta/química , Extractos Vegetales/efectos adversos , Extractos Vegetales/aislamiento & purificación , Tallos de la Planta/química , Alcaloides de la Vinca/efectos adversos , Alcaloides de la Vinca/aislamiento & purificación , Adulto Joven
6.
Lancet Microbe ; 3(8): e598-e605, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35654079

RESUMEN

BACKGROUND: High-quality evidence for the therapeutic efficacy and effectiveness of antimalarials for infections caused by Plasmodium malariae, Plasmodium ovale spp, and mixed-Plasmodium infections is scarce. In this study, we aimed to analyse the efficacy of pyronaridine-artesunate for the treatment of non-falciparum and mixed-species Plasmodium infections from a large phase 3b/4 clinical trial in central Africa. METHODS: This post-hoc analysis was done in a random subset of samples from two sites (in the Democratic Republic of the Congo and in Gabon) of the CANTAM-Pyramax trial assessing pyronaridine-artesunate therapy. We randomly selected paired dried blood spot samples from day 0 and day 28 (or unforeseen visit) and analysed them by quantitative PCR for mixed Plasmodium infections or non-falciparum mono-infections. Day 28 (or unforeseen visit) samples positive for non-falciparum malaria were re-assessed by microscopy to identify microscopic versus submicroscopic infections. Analyses were done on two sample sets: a per-protocol set and an intention-to-treat set. FINDINGS: Among 1502 randomly selected samples, 192 (12·8%) showed mixed-Plasmodium infections or non-falciparum mono-infections. We did not detect P vivax in the samples. For both the per-protocol and intention-to-treat sets, the overall day 28 cure rates for P malariae, P ovale curtisi, and P ovale wallikeri were 96·3% or higher (95% CIs from 81·0-99·9 to 95·7-100). Cure rates were consistently high in P malariae (99·2%, 95·7-100) and P ovale spp (97·9%, 88·7-99·9, for P ovale curtisi and 96·3%, 81·0-99·9, for P ovale wallikeri) infections. INTERPRETATION: This post-hoc analysis provides important evidence supporting the high efficacy of pyronaridine-artesunate against mono-infections with P malariae, P ovale curtisi, or P ovale wallikeri and mixed-Plasmodium infections in a real-world setting. FUNDING: Medicines for Malaria Venture.


Asunto(s)
Malaria , Plasmodium ovale , Artesunato , Combinación de Medicamentos , Humanos , Malaria/tratamiento farmacológico , Naftiridinas , Plasmodium malariae , Plasmodium ovale/genética
7.
Planta Med ; 77(2): 111-6, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20665369

RESUMEN

The aim of this study was to evaluate the short-term safety and tolerability of an antimalarial herbal medicinal product (PR 259 CT1) consisting of a quantified 80 % ethanol extract from the stem bark of Nauclea pobeguinii when given orally to healthy adult male volunteers. The amount of the major alkaloid strictosamide in the extract was determined by a validated HPLC method and was shown to be 5.6 %. The herbal preparation was formulated in a gelatine capsule form containing 500 mg of PCR 259 CT1. A sample of 15 healthy male volunteers, selected using the Lot Quality Assurance of Sampling (LQAS) method, was eligible for inclusion after fulfillment of the inclusion criteria and clinical examination by a physician. The volunteers were treated in an outpatient clinic with a drug regimen of two 500 mg capsules three times daily (each eight hours) for seven days, during meals. Safety and tolerability were monitored clinically, haematologically, biochemically and by electrocardiographic (ECG) examination at days 0, 1, 3, 7 and 14. Adverse effects were recorded by self-reporting of the participants or by detection of abnormalities in clinical examinations by a physician. The oral administration of PR 259 CT1 at high doses of 2 × 500 mg/capsule/day for 7 days was found to induce no significant changes in the concentration levels of all investigated haematological, biochemical, electrocardiogram and vital sign parameters and physical characteristics after 14 days of treatment compared to those seen in the baseline data. The concentration levels of all evaluated parameters were within the normal limits as reported in the literature. All adverse events noted were mild and self-resolving including increase of appetite (33 %), headache (20 %) and nausea (20 %). Other minor side effects were insomnia, somnolence and asthenia (7 %). Thus, PR 259 CT1 presented a significant safety and tolerability in healthy volunteers to allow its further development by starting a phase II clinical trial.


Asunto(s)
Antimaláricos/normas , Malaria/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/normas , Rubiaceae/química , Administración Oral , Adulto , Antimaláricos/efectos adversos , Antimaláricos/uso terapéutico , Electrocardiografía , Etanol , Humanos , Muestreo para la Garantía de la Calidad de Lotes , Masculino , Corteza de la Planta/química , Extractos Vegetales/efectos adversos , Extractos Vegetales/uso terapéutico , Tallos de la Planta/química , Plantas Medicinales/química , Estudios Prospectivos , Seguridad , Factores de Tiempo , Adulto Joven
8.
PLoS One ; 14(9): e0222379, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31527899

RESUMEN

INTRODUCTION: Artemisinin-based combination therapy is currently the best option for the treatment of uncomplicated malaria. Quinine is recommended as a rescue treatment. Safety information during repeated treatment with the same drug is scarce. We report safety data from the Quinact randomized clinical trial (RCT) that was designed to assess efficacy and safety of artesunate-amodiaquine (ASAQ), artemether-lumefantrine (AL) and quinine+clindamycin (QnC). METHODOLOGY: Males and females aged 12 to 59 months with uncomplicated malaria were treated with ASAQ and followed up during 42 days (preRCT). Clinical failures were randomized to one of the 3 treatments and followed up for 28 days (RCT). Subsequent failures were repeatedly treated with ASAQ several times as needed (postRCT1, postRCT2 and so on) until a 28-days follow up period without parasitaemia. RESULTS: Eight hundred and sixty-five, 242 and 64 patients were recruited respectively in preRCT, RCT and postRCTs. In preRCT, 433 (50.0%) patients experienced at least one drug-related adverse event (AE). The most reported AEs were anorexia (22.9%), asthenia (19.4%), and abnormal behavior (14.6%). Twenty-nine AEs (3.5%) were reported to be severe. In RCT, at least one drug-related AE was reported in 54.7%, 21.5% and 40.0% of patient randomized respectively to ASAQ, AL and QnC (p<0.001). During postRCT1 (n = 64), postRCT 2 (n = 17) and postRCT3 (n = 7), respectively 32.8%, 35.3% and 71.4% of patients experienced at least one drug-related AE. Three serious adverse events occurred but not judged related to study medication. CONCLUSION: The proportion of AEs did not increase over the treatment courses with ASAQ. However, continuous monitoring is important.


Asunto(s)
Antimaláricos/efectos adversos , Antimaláricos/uso terapéutico , Clindamicina/efectos adversos , Clindamicina/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Plasmodium falciparum/efectos de los fármacos , Amodiaquina/administración & dosificación , Amodiaquina/efectos adversos , Amodiaquina/uso terapéutico , Antibacterianos/efectos adversos , Antibacterianos/uso terapéutico , Arteméter/efectos adversos , Arteméter/uso terapéutico , Combinación Arteméter y Lumefantrina/efectos adversos , Combinación Arteméter y Lumefantrina/uso terapéutico , Artemisininas/efectos adversos , Artemisininas/uso terapéutico , Artesunato/efectos adversos , Artesunato/uso terapéutico , Preescolar , República Democrática del Congo , Combinación de Medicamentos , Femenino , Humanos , Lactante , Lumefantrina/administración & dosificación , Malaria Falciparum/parasitología , Masculino , Quinina/efectos adversos , Quinina/uso terapéutico
9.
Vaccine ; 36(41): 6170-6182, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-30190119

RESUMEN

BACKGROUND: In early 2016, there was a Yellow Fever (YF) outbreak in Central Africa with several deaths reported from Angola and the Democratic Republic of Congo. Due to a shortage in vaccine supply, fractional dosing (0.1 ml) of 17DD Yellow Fever Vaccine (YFV) was proposed in preventive vaccination campaign in Kinshasa in August 2016. A Pharmacovigilance surveillance at community level was implemented to track Adverse Events Following Immunization (AEFIs). The objective of this study was to describe AEFIs as captured from community-based pharmacovigilance and to compare the safety profile of the fractional dosing of YFV between gender. METHODS: PV information sessions were organized in churches, academic institutions, and pediatrician, obstetrician and friend networks. Prior to data collection, education about AEFI was provided through face-to-face discussions, phone calls, SMS and WhatsApp messages. Individuals reported AEFIs though the above communication channels to assigned individuals. Reported AEFIs were entered into VigiFlow and extracted for statistical analysis using Stata 12. Only vaccinees who received fractional dose (subjects from the age of 2-year-old and non-pregnant women) were included in analysis. Proportional t-test was used to compare AEFI preferred terms among males and females. RESULTS: A total of 4020 subjects reported 5409 AEFIs. Reporters were mostly males (54.9%) with an average age of 26 ±â€¯10.7 years. Fever and injection site pain were the most reported systemic and local AEFI respectively. The safety profile was similar between gender although females reported more diarrhea and dizziness whilst males reported more asthenia (P < 0.001). Five individuals reported serious AEFIs. Among them, 4 were less-immunocompetent. CONCLUSION: Fractional dosing of 17DD YFV has a good safety profile, which is similar between gender. These findings complement the documented immunogenicity profile to support recommendation of fractional dose of YFV for outbreak control.


Asunto(s)
Vacuna contra la Fiebre Amarilla/administración & dosificación , Vacuna contra la Fiebre Amarilla/efectos adversos , Adolescente , Adulto , República Democrática del Congo , Femenino , Humanos , Masculino , Vacunación/efectos adversos , Fiebre Amarilla/prevención & control , Adulto Joven
10.
J Ethnopharmacol ; 174: 607-17, 2015 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-26079563

RESUMEN

UNLABELLED: Ethnoparmaological relevance: One of the possible methodologies for the discovery of novel drugs is the screening of selected plant extracts for a broad array of pharmacological activities. MATERIALS AND METHODS: The selection based on enthnomedicinal uses, combined with a follow-up of existing literature on the plants' chemotaxonomic properties, would seem to be the most cost-effective strategy for finding active plant extracts. A bioassay-guided fractionation of the active extracts should subsequently lead to the isolation and identification of the active lead constituent(s). RESULTS AND DISCUSSION: Taking into account the enormous number and the amazing structural diversity of the currently known plant constituents, one might hope that promising model compounds with new structures and/or novel mechanisms of action might be found. In order, however, to optimize such a natural product drug discovery methodology, dereplication and selectivity of activity should be included in the screening system. Dereplication by which known compounds can rapidly be identified from a partially purified mixture prevents a research group from wasting resources by rediscovering known compounds. The use of single-target specific bioassays such as tests on isolated enzymes or on receptor-binding, or multiple target functional bioassays on isolated organs or intact cells must allow at an early stage to isolate compounds with specific pharmacological properties. CONCLUSIONS: In this publication, several examples of bioassay-guided isolation and identification of pharmacologically active lead compounds from plants used in Central-African traditional medicine by our research group will be presented and discussed.


Asunto(s)
Medicinas Tradicionales Africanas , África Central , Animales , Descubrimiento de Drogas , Etnofarmacología , Humanos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Plantas Medicinales/química
11.
Eur J Pharmacol ; 60(4): 329-36, 1979 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-230981

RESUMEN

SC4453 is a digoxin analogue with a pyridazine instead of a lactone ring on C17 beta. SC4453 was compared with digoxin with respect to inhibition of (Na+ + K+)-ATPase prepared from human heart, guinea-pig heart and guinea-pig brain. SC4453 was slightly less potent than digoxin but showed a similar sensitivity to K+. As for cardenolides, species differences in sensitivity to SC4453 were accounted for by differences in the rate of dissociation from the receptors. These observations confirm that the human heart is one of the tissues most sensitive to cardiac glycosides.


Asunto(s)
Encéfalo/enzimología , Digoxina/análogos & derivados , Digoxina/farmacología , Miocardio/enzimología , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Animales , Glicósidos Cardíacos/farmacología , Femenino , Cobayas , Semivida , Humanos , Técnicas In Vitro , Masculino , Piridazinas/farmacología , Especificidad de la Especie , Factores de Tiempo
12.
J Ethnopharmacol ; 142(3): 620-6, 2012 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-22609154

RESUMEN

AIM OF THE STUDY: To evaluate the antidiarrhoeal properties of Alstonia congensis leaves claimed to be effective for the treatment of diarrhoea by traditional healers during our ethnopharmacological investigation conducted in Kinshasa, Democratic Republic of Congo. MATERIALS AND METHODS: The aqueous extract (decoction), and the 80% hot methanol extract (Soxhlet extraction) were obtained. This last extract was fractionated. The antidiarrhoeal activity was evaluated using castor oil and magnesium sulphate-induced diarrhoea in animals. The potential antibacterial activity of all samples was also assessed in vitro. RESULTS: At all oral doses of 100 and 200 mg/kg body weight, all A. congensis samples showed significant and dose-dependent antidiarrhoeal activity in treated Wistar rats characterised by significant increase of onset time and decrease of all other diarrhoeal parameters at various degrees compared to untreated groups in both models. At the highest oral dose of 200 mg/kg bodyweight, the 80% hot methanol and aqueous extracts produced 79.8 ± 2.1% and 78.6 ± 0.5%, and 75.0 ± 2.1% and 71.4 ± 2.1% inhibition of defecation and diarrhoea respectively against castor oil-induced diarrhoea, and 75.0 ± 1.2% and 73.3±1.2% inhibition of diarrhoea respectively against magnesium sulphate-induced diarrhoea. The 80% hot methanol and aqueous detannified extracts showed low activity (42-47% inhibition of defecation and/or diarrhoea in both tests) suggesting that tannins may be responsible for the observed activity. At the same oral doses, the total alkaloid extract, the chloroform soluble fraction rich in alkaloids, the 80% methanol and the alkaline aqueous soluble subfractions produced more than 50% inhibition of defecation and/or diarrhoea in both tests. From the antibacterial testing in vitro, results indicated that all A. congensis samples exhibited an antibacterial activity mainly against bacteria implicated in diarrhoea with MIC and MBC values in the range of 15.6-500 µg/ml. The most active samples were the aqueous (decoction) and the 80% hot methanol dried extracts, the chloroform subfraction rich in alkaloids and the total alkaloid extract (MIC: 15.7-125 µg/ml, MBC: 31.2-250 µg/ml). Proteus varibilis was found to be the most resistant microorganism. CONCLUSION: These reported results can partly support and justify the traditional use of extracts from Alstonia congensis leaves for the treatment of diarrhoea in tradittional medicine.


Asunto(s)
Alstonia , Antibacterianos/uso terapéutico , Antidiarreicos/uso terapéutico , Diarrea/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/uso terapéutico , Animales , Antibacterianos/farmacología , Antidiarreicos/farmacología , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Aceite de Ricino , Diarrea/inducido químicamente , Sulfato de Magnesio , Metanol/química , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/farmacología , Hojas de la Planta/química , Ratas , Ratas Wistar , Solventes/química
13.
Planta Med ; 72(8): 751-3, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16732537

RESUMEN

An aqueous decoction (dried extract), an 80 % methanolic extract from Morinda morindoides (Rubiaceae) leaves, and five iridoids isolated from the 80 % methanolic extract were evaluated in vitro for their activity against Entamoeba histolytica and their cytotoxicity. The aqueous decoction and the 80 % methanolic extract exhibited a promising antiamoebic activity with IC (50) values of 3.1 +/- 1.7 and 1.7 +/- 0.6 microg/mL, respectively. All tested iridoids displayed antiamoebic activity, the most active being epoxygaertneroside (IC (50): 1.3 +/- 0.4 microg/mL) and methoxygaertneroside (IC (50): 2.3 +/- 0.7 microg/mL) followed by gaertneroside, acetylgaertneroside and gaertneric acid with IC (50) values of 4.3 +/- 1.8, 5.4 +/- 1.4 and 7.1 +/- 1.4 microg/mL, respectively. Synergistic effects between the iridoids tested, or with other constituents, may explain the high activity of the extracts. All extracts and iridoids were devoid of any cytotoxic effect against MT-4 cells at the highest test concentration of 250 microg/mL. These findings support at least in part the traditional use of Morinda morindoides leaves for the treatment of amoebiasis in the Democratic Republic of Congo.


Asunto(s)
Amebicidas/farmacología , Amoeba/efectos de los fármacos , Morinda , Fitoterapia , Extractos Vegetales/farmacología , Amebiasis/tratamiento farmacológico , Amebicidas/administración & dosificación , Amebicidas/uso terapéutico , Animales , Humanos , Pruebas de Sensibilidad Parasitaria , Extractos Vegetales/administración & dosificación , Extractos Vegetales/uso terapéutico , Hojas de la Planta
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