Assessment of biodiversity goods for the sustainable development of the chagra in an indigenous community of the Colombian Amazon: local values of crops.

BACKGROUND: The chagra is the agroforestry system adapted to the characteristics of the Amazon region. Recently, there has been a reported loss of biodiversity and traditional knowledge associated with the chagras. This paper characterizes the cultivators, exploring knowledge and expressed value perception in the context of the Amazonian chagra of an indigenous community; also, this prioritizes species, under the optics of commercial opportunity. METHODS: A semi-structured instrument was applied to 14 volunteers, asking about marketing preferences and use values of the species; later, a floristic inventory and prioritization workshop was developed. RESULTS: Sixty-two percent of the participants were 50 years or older at the time of the interview. Open conversations showed that traditional knowledge is a matter of practice; and is maintained mainly by the older "grandfathers". Thirty-eight species, belonging to 28 different families, were reported, showing considerable diversity. Seventy-nine percent of the participants consider the Leticia market and sales to tourists as the main marketing scenarios. CONCLUSIONS: The Ziora-Amena community centralizes the handling of chagras in the community's older adults, who transmit their traditional knowledge to new generations through oral tradition. Indicators of preference, use, and abundance highlight the food species. The perception of the trade stakeholder encourages research and development of endemic species, with health properties or ingredients for industry, which represent an opportunity of high added value for the region.

Alsinol, an arylamino alcohol derivative active against Plasmodium, Babesia, Trypanosoma, and Leishmania: past and new outcomes.

Malaria, babesiosis, trypanosomosis, and leishmaniasis are some of the most life-threatening parasites, but the range of drugs to treat them is limited. An effective, safe, and low-cost drug with a large activity spectrum is urgently needed. For this purpose, an aryl amino alcohol derivative called Alsinol was resynthesized, screened in silico, and tested against Plasmodium, Babesia, Trypanosoma, and Leishmania. In silico Alsinol follows the Lipinski and Ghose rules. In vitro it had schizontocidal activity against Plasmodium falciparum and was able to inhibit gametocytogenesis; it was particularly active against late gametocytes. In malaria-infected mice, it showed a dose-dependent activity similar to chloroquine. It demonstrated a similar level of activity to reference compounds against Babesia divergens, and against promastigotes, and amastigotes stages of Leishmania in vitro. It inhibited the in vitro growth of two African animal strains of Trypanosoma but was ineffective in vivo in our experimental conditions. It showed moderate toxicity in J774A1 and Vero cell models. The study demonstrated that Alsinol has a large spectrum of activity and is potentially affordable to produce. Nevertheless, challenges remain in the process of scaling up synthesis, creating a suitable clinical formulation, and determining the safety margin in preclinical models.

Comparison of the antimalarial activity of a Colombian traditional Uitoto remedy with laboratory preparations.

BACKGROUND & OBJECTIVES: In Colombian Amazonia, Uitoto indigenous people use a preparation of Curarea toxicofera (Menispermaceae) to prevent and treat malaria. To open the way for the production of a standardized herbal remedy, we compared the activity of the traditional preparation with laboratory preparations. METHODS: People were interviewed on their mode of use and preparation of what is considered the best remedy against fevers in this area. The herbal remedy was prepared according to the healer's recommendations. The plant was also submitted to continuous distillation and percolation extraction. The preparations were then tested against Plasmodium falciparum, in vitro. Traditional preparation and extract obtained by percolation were tested on Plasmodium berghei infected mice. Chemical profiles were also explored by thin-layer chromatography. RESULTS: Yields of extraction were around 7% in the preparations (percolation was the most efficient). The phytochemical profile showed a mix of steroids, flavonoids and alkaloids qualitatively similar in all preparations. In vitro, the extracts showed inhibitory concentration 50 <10µg/mL: the traditional preparation was almost three times less active than laboratory preparations. In vivo, percolation was also more active than traditional preparation, inhibiting 78% of the parasite growth at 400mg/kg/day by oral route. INTERPRETATION & CONCLUSION: Pharmacological activities suggest that both the original remedy (prepared according to traditional pharmacopeia) and the extracts obtained by percolation extraction exhibit relevant antiparasitic activity. C. toxicofera should therefore be considered for the elaboration of an improved traditional medicine by implementing toxicological studies and carefully following quality control guidelines for its preparation.

Structure-activity relationship of new antimalarial 1-aryl-3-susbtituted propanol derivatives: Synthesis, preliminary toxicity profiling, parasite life cycle stage studies, target exploration, and targeted delivery.

Design, synthesis, structure-activity relationship, cytotoxicity studies, in silico drug-likeness, genotoxicity screening, and in vivo studies of new 1-aryl-3-substituted propanol derivatives led to the identification of nine compounds with promising in vitro (55, 56, 61, 64, 66, and 70-73) and in vivo (66 and 72) antimalarial profiles against Plasmodium falciparum and Plasmodium berghei. Compounds 55, 56, 61, 64, 66 and 70-73 exhibited potent antiplasmodial activity against chloroquine-resistant strain FCR-3 (IC50s < 0.28 µM), and compounds 55, 56, 64, 70, 71, and 72 showed potent biological activity in chloroquine-sensitive and multidrug-resistant strains (IC50s < 0.7 µM for 3D7, D6, FCR-3 and C235). All of these compounds share appropriate drug-likeness profiles and adequate selectivity indexes (77 < SI < 184) as well as lack genotoxicity. In vivo efficacy tests in a mouse model showed compounds 66 and 72 to be promising candidates as they exhibited significant parasitemia reductions of 96.4% and 80.4%, respectively. Additional studies such as liver stage and sporogony inhibition, target exploration of heat shock protein 90 of P. falciparum, targeted delivery by immunoliposomes, and enantiomer characterization were performed and strongly reinforce the hypothesis of 1-aryl-3-substituted propanol derivatives as promising antimalarial compounds.

Pharmacological activity of Curarea toxicofera in combination with classical antimalarial treatments.

ETHNOPHARMACOLOGICAL RELEVANCE: In the Leticia-Amazonas area, Uitoto indigenous people use a preparation of Curarea toxicofera (Wedd) Barneby & Krukoff (Menispermaceae) alone or combined with prescribed medications to prevent and treat malaria. AIM OF STUDY: To determine the in vitro and in vivo antiplasmodial activity of traditional preparations of Curarea toxicofera alone and in combination with classical antimalarials. MATERIAL AND METHODS: The traditional preparation was evaluated in vitro against P. falciparum FCR3 CQ resistant strain, alone and combined. The preparation was further administered orally alone or combined with chloroquine and artesunate in mice infected with Plasmodium berghei ANKA strain on the four-day antimalarial test model. RESULTS: The herbal remedy used alone was able to significantly decrease the parasitemia both in vitro (IC50 7.3 µg/ml) and in vivo (ED50 328 mg/Kg) but it was less active than chloroquine (IC50 0.29 µg/ml in vitro and ED50 2.3 mg/Kg/day in vivo), and than artesunate (IC50 0.002 µg/ml and ED50 3.7 mg/Kg/day). Interestingly it presented synergism with chloroquine in vitro (Combination Index: 0.39) and in vivo; and was additive with artesunate in vitro (Combination Index: 0.94) and in vivo. CONCLUSION: The traditional preparation showed potential as an antimalarial and, when used in combination, does not negatively affect the efficacy of the drugs evaluated. Pre-clinical studies should be conducted with a standardized preparation to confirm its efficacy and safety alone and in combination with chloroquine and artesunate.

Adaptation and optimization of a fluorescence-based assay for in vivo antimalarial drug screening.

The in vivo efficacy of potential antimalarials is usually evaluated by direct microscopic determination of the parasitaemia of Plasmodium-infected mice on Giemsa-stained blood smears. This process is time-consuming, requires experienced technicians and is not automatable. Therefore, we optimized a SYBR Green I (SYBRG I) fluorescence-based assay to fluorometers commonly available in many research laboratories. This technique was originally developed to assess parasitaemia in humans by cytometry. We defined optimal conditions with Plasmodium berghei-infected mice, standard lysis buffer (Tris, EDTA, saponin and Triton), whole blood cells and 2 h staining incubation with SYBRG I 2X. The fluorescence background generated by uninfected whole blood cells was low (around 4.6%), and the linearity high (r 2 = 0.96), with parasitaemia ranging from 1.4 to 60%. The Bland-Altman plot showed a strong correlation between SYBRG I and Giemsa gold standard method; Z'-factor was >0.5. These findings suggest that our fluorescence-based assay is suitable for in vivo antimalarial drug assessment in a malaria murine model. It can help to overcome the human bias found with microscopic techniques.

Exploring the scope of new arylamino alcohol derivatives: Synthesis, antimalarial evaluation, toxicological studies, and target exploration.

Synthesis of new 1-aryl-3-substituted propanol derivatives followed by structure-activity relationship, in silico drug-likeness, cytotoxicity, genotoxicity, in silico metabolism, in silico pharmacophore modeling, and in vivo studies led to the identification of compounds 22 and 23 with significant in vitro antiplasmodial activity against drug sensitive (D6 IC50 ≤ 0.19 µM) and multidrug resistant (FCR-3 IC50 ≤ 0.40 µM and C235 IC50 ≤ 0.28 µM) strains of Plasmodium falciparum. Adequate selectivity index and absence of genotoxicity was also observed. Notably, compound 22 displays excellent parasitemia reduction (98 ± 1%), and complete cure with all treated mice surviving through the entire period with no signs of toxicity. One important factor is the agreement between in vitro potency and in vivo studies. Target exploration was performed; this chemotype series exhibits an alternative antimalarial mechanism.

In vitro susceptibility of Plasmodium vivax to antimalarials in Colombia.

The in vitro susceptibilities of 30 isolates of Plasmodium vivax to a number of antimalarials (chloroquine [CQ], mefloquine, amodiaquine, quinine, and artesunate [AS]) were evaluated. The isolates came from the region of Urabá in Colombia, in which malaria is endemic, and were evaluated by the schizont maturation test. The 50% inhibitory concentration (IC50) was 0.6 nM (95% confidence interval [CI], 0.3 to 1.0 nM) for artesunate, 8.5 nM (95% CI, 5.6 to 13.0 nM) for amodiaquine, 23.3 nM (95% CI, 12.4 to 44.1 nM) for chloroquine, 55.6 nM (95% CI, 36.8 to 84.1 nM) for mefloquine, and 115.3 nM (95% CI, 57.7 to 230.5 nM) for quinine. The isolates were classified according to whether the initial parasites were mature or immature trophozoites (Tfz). It was found that the IC50s for chloroquine and artesunate were significantly different in the two aforementioned groups (P < 0.001). The IC50s of CQ and AS were higher in the isolates from mature Tfz (CQ, 39.3 nM versus 17 nM; AS, 1.4 nM versus 0.3 nM), and 10% of the isolates showed lower susceptibilities to one of the antimalarial drugs, 13.3% to two antimalarial drugs, and 3.3% to more than three antimalarial drugs. It should be highlighted that despite the extensive use of chloroquine in Colombia, P. vivax continues to be susceptible to antimalarials. This is the first report, to our knowledge, showing in vitro susceptibilities of P. vivax isolates to antimalarials in Colombia.

The in vivo antimalarial activity of methylene blue combined with pyrimethamine, chloroquine and quinine.

The effectiveness of methylene blue (MB) combined with pyrimethamine (PYR), chloroquine (CQ) or quinine (Q) was examined in a classical four-day suppressive test against a causative agent of rodent malaria, Plasmodium berghei. A marked potentiation was observed when MB was administered at a non-curative dose of 15 mg/kg/day in combination with PYR (0.19 mg/kg/day) or Q (25 mg/kg/day). No synergy was found between MB (15 mg/Kg) and CQ (0.75 mg/Kg). Our results suggest that the combination of MB with PYR or Q may improve the efficacy of these currently used antimalarial drugs.

The in vivo antimalarial activity of methylene blue combined with pyrimethamine, chloroquine and quinine

The effectiveness of methylene blue (MB) combined with pyrimethamine (PYR), chloroquine (CQ) or quinine (Q) was examined in a classical four-day suppressive test against a causative agent of rodent malaria, Plasmodium berghei. A marked potentiation was observed when MB was administered at a non-curative dose of 15 mg/kg/day in combination with PYR (0.19 mg/kg/day) or Q (25 mg/kg/day). No synergy was found between MB (15 mg/Kg) and CQ (0.75 mg/Kg). Our results suggest that the combination of MB with PYR or Q may improve the efficacy of these currently used antimalarial drugs.

Aryl piperazine and pyrrolidine as antimalarial agents. Synthesis and investigation of structure-activity relationships.

Piperazine and pyrrolidine derivatives were synthesised and evaluated for their capacity to inhibit the growth of Plasmodium falciparum chloroquine-resistant (FCR-3) strain in culture. The combined presence of a hydroxyl group, a propane chain and a fluor were shown to be crucial for the antiplasmodial activity. Five compounds of the aryl-alcohol series inhibited 50% of parasite growth at doses ≤10 µM. The most active compound 1-(4-fluoronaphthyl)-3-[4-(4-nitro-2-trifluoromethylphenyl)piperazin-1-yl] propan-1-ol was almost 20-40 times more active on P. falciparum (IC(50): 0.5 µM) than on tumorogenic and non-tumorogenic cells. In vivo it has a very weak effect; inhibiting 35% of parasite growth only, at 10 mg/kg/day against Plasmodium berghei infected mice without any impact on survival time. In silico molecular docking study and molecular electrostatic potential calculation revealed that this compound bound to the active site of Plasmodium plasmepsin II enzyme.

Revisión documental de los productos naturales legalmente autorizados para su mercadeo en Colombia / Documental revision of the natural products authorized for marketing in Colombia

Introducción: El grupo de los productos naturales ha cobrado gran interés en los últimos años debido a la creencia popular que son eficaces y más seguros que los medicamentos de síntesis o por recientes tendencias en salud que buscan suplementar la alimentación.Objetivo: Describir el grupo de los productos naturales desde el punto de vista de la autoridad sanitaria.Metodología: Estudio observacional descriptivo de corte transversal a partir del universo de los Registros Sanitarios de Productos Naturales que presenta la base de datos del Instituto Nacional de Vigilancia de Medicamentos y Alimentos (Autoridad Sanitaria Colombiana).Resultados: Aproximadamente la mitad de los productos naturales legalmente aceptados para su mercadeo son productos fitoterapéuticos y la otra mitad la componen los suplementos dietarios junto con los productos de uso específico. La especie vegetal con mayor número de autorizaciones de comercialización es la alcachofa (Cynara scolymus), seguida de caléndula (Calendula officinalis), valeriana (Valeriana officinalis), ajo (Allium sativum) y ginkgo (Ginkgo biloba). Hay un predominio del empleo de especies foráneas en los productos fitoterapéuticos comercializados. Se propone una clasificación novedosa del órgano de la planta o droga empleado en la producción con la cual es evidente el mayor uso de las hojas respecto a cualquier otro órgano. Cápsulas, tabletas y soluciones son las formas farmacéuticas predominantes...

Introduction: The group of natural products has gained much interest in recent years because of the popular belief that they are effective and more secure than synthetic medications, or because of recent health tendencies seeking to supplement nutrition. Objective: To describe the group of natural products from a sanitary authority point of view. Methodology: Observational, descriptive, cross-sectional study from the universe of Drug approvals of Natural Products presented by a database from the Instituto Nacional de Vigilancia de Medicamentos y Alimentos (Colombian Sanitary Authority). Results: Nearly half of the natural products legally accepted for marketing are herbal medicines and the other half are dietary supplements, along with specific-use products. The vegetable species with the greatest number of commercialization authorizations is artichoke Cynara scolymus (alcachofa), followed by calendula (Calendula officinalis), valerian (Valeriana officinalis), garlic (Allium sativum), and ginkgo (Ginkgo biloba). Foreign species predominate in the fabrication of commercialized herbal medicines. A novel classification is proposed of the plant organ or drug employed in the production with which it is evident that leaves are used more with respect to any other plant organ. Capsules, tablets, and solutions are the predominant pharmaceutical forms...

Hallazgos complementarios sobre la actividad antimalárica del azul de metileno y su toxicidad / Complementary findings on the antimalarial activity and toxicity of methylene blue

En 1881, Ehrlich reportó el azul de metileno como el primer antimalárico sintético, pero dejo de ser empleado con este propósito; el debe ser reconsiderado pues son necesarias con urgencia nuevas alternativas de bajo costo, en el arsenal de medicamentos antimaláricos. En este trabajo la actividad antimalárica del azul de metileno es evaluada in vivo frente a parásitos de malaria murina. Una dosis de 15 mg/kg/día inhibe el 50 por ciento del crecimiento eritrocítico parasitario de Plasmodium berghei y P. yoelii nigeriensis, en tanto que es prácticamente inactivo frente a los estadíos hepáticos de P. yoelii yoelii. Sobre un cultivo de la línea celular linfoblástica BJAB, el azul de metileno es 20 veces más citotóxico que la cloroquina, no obstante el azul de metileno presenta valores de índice de selectividad del mismo nivel que la cloroquina, frente a varias cepas de P. falciparum de diferentes niveles de sensibilidad y provenientes de diferentes lugares geográficos

A non-radiolabeled heme-GSH interaction test for the screening of antimalarial compounds.

Intraerythrocytic Plasmodium produces large amounts of toxic heme during the digestion of hemoglobin, a parasite specific pathway. Heme is then partially biocristallized into hemozoin and mostly detoxified by reduced glutathione. We proposed an in vitro micro assay to test the ability of drugs to inhibit heme-glutathione dependent degradation. As glutathione and o-phthalaldehyde form a fluorescent adduct, we followed the extinction of the fluorescent signal when heme was added with or without antimalarial compounds. In this assay, 50 microM of amodiaquine, arthemether, chloroquine, methylene blue, mefloquine and quinine inhibited the interaction between glutathione (50 microM) and heme (50 microM), while atovaquone did not. Consequently, this test could detect drugs that can inhibit heme-GSH degradation in a fast, simple and specific way, making it suitable for high throughput screening of potential antimalarials.

Actividad Leishmanicida y tripanocida de algunas plantas reportadas como medicinales en Colombia / Activity Leishmanicida and tripanocida of some plants reported as medicinal in Colombia

Ocho extractos crudos y dos fracciones de alcaloides obtenidos de siete especies vegetales provenientes de la flora colombiana, (abuta grandifolia, Piper holtonii, Acnistus arborescens, Croton leptostachys, Piper cumanense, Acacia farnesiana y Xilopia aromática) fueron evaluadas in vitro frente a tres especies de Leishmania danovanni y Leismania braziliensis y epimastigotes de Trypanosoma cruzi (tulahuen); dos de estas epecies (Acnistus arborescens y Piper cumanense) mostraron alta actividad en los ensayos realizados con valores de concentración inhibitoria 50 (CL50) menores de 12,5 ug/mL; cercanos a los obtenidos con el fármaco de referencia pentamidina 10 ug/mL.