3D7 Strain Research Articles

Black tea kombucha: Physicochemical, microbiological and comprehensive phenolic profile changes during fermentation, and antimalarial activity

This study shows the changes in physicochemical and microbiological composition, and in the phenolic profile of black tea kombucha during fermentation. In addition, the antimalarial potential of the kombucha was evaluated. Ultra-performance liquid chromatography-mass spectrometry multiplex analysis (UPLC-MSE) results revealed a 1.7 log2 fold-change increase in phenolics with the fermentation time, with emphasis on the increase of phenolic acids (0.3 log2 fold-change). Over time there was degradation of flavonoids such as nepetin, hesperidin and catechin 5-O-gallate, to the detriment of the increase in phenolic acids such as gallic acid and cinnamic acid. In addition, black tea kombucha presented antiplasmodic activity against the 3D7 (sensitive chloroquine) and W2 (resistant to chloroquine) strains. Therefore, important changes in the black tea kombucha phenolic profile take place during fermentation, which may help in the development of kombuchas with higher bioactive potential and contribute to a better understanding of the kombucha fermentation process.

Synthesis, anticancer and antimalarial activities of organosulfur and organoselenium derivatives of cyclopentadienyliron dicarbonyl as photoCORMs

The reactions of [CpFe(CO)2]2 with 2 mol equivalents of R2E2 (R = C6H11, C4H3S, CH2C6H5; E = S, Se) have yielded dinuclear products of [CpFe(CO)(μ-L)]2 (L = C6H11S (1), C4H3S2 (2) and CH2C6H5Se (3)), respectively. An additional trinuclear compound, C24H22O2Se2Fe3 (4) was isolated only from the reaction with dibenzyl diselenide. All the products have been fully characterized by FT-IR,1H and13C NMR, CHN elemental analysis, and structurally elucidated by single crystal X-ray diffraction. The stability of 1–3 both under dark and UV conditions were investigated by monitoring the changes in their respective UV–Vis spectra in phosphate buffered saline (PBS) solution. Their potential application as photoCORMs were also evaluated by standard myoglobin assay. 2 showed the shortest half-life and highest equivalent of CO-released. The anticancer studies of 1–3 were evaluated in-vitro on breast cancer cell lines (MCF-7, MDA-MB-231 and MDA-MB-468) and the cytotoxicity of 2 had increased approximately 4 times against MDA-MB-468 cell line upon UV irradiation, which was 11.5 ± 2.7 μM. All complexes exhibited cytotoxic effect on specific sub-types of breast cancer cells. Antimalarial activities of 1–3 had also been studied and reported in this work. Unfortunately, these complexes did not display any significant effect on the Plasmodium falciparum 3D7 strains.

Biodegradation of crude oil by a moderately haloalkaliphilic Acinetobacter strain

Bioremediation of crude oil (or petroleum) pollution in the saline-alkali environment is challenging due to the lack of halotolerant and alkali tolerant oil-degrading bacteria. It is shown here that a newly isolated Acinetobacter strain D2 able to degrade crude oil was moderately haloalkaliphilic. Physiological characterization showed that the optimal crude oil degradation conditions for D2 strain occurred at pH = 9 and NaCl concentration of 2% w/v. Moreover, D2 can tolerate pH 11 and NaCl concentration of 8% w/v. Kinetic analysis indicated that crude oil (0.2% and 0.5% w/v) biodegradation by D2 followed the first-order kinetic model, with the k constant estimated as 0.089–0.111 d−1 and the half-life period of petroleum degradation as 6.24–7.79 d. The results of the gas chromatographic analysis revealed that strain D2 could degrade most saturated hydrocarbons, with higher removal efficiencies for shorter-chain alkanes. Strain D2 can also remove aromatic hydrocarbons with an average efficiency of 33.4%. Combined, these results demonstrated that a moderately haloalkaliphilic Acinetobacter strain can be a suitable candidate for bioremediation of oil-contaminated saline soil and oilfield produced water.

Functionalized Boron Nanoparticles as Potential Promising Antimalarial Agents.

Boron nanoparticles (BNPs), functionalized with hydroxyl groups, were synthesized in situ by a cascade process, followed by bromination and hydrolyzation reactions. These functionalized BNPs, (Bm(OH)n), were characterized using 1H and 11B NMR spectra, Fourier-transform infrared (FT-IR) spectroscopy, inductively coupled plasma-optical emission spectroscopy (ICP-OES), transmission electron microscopy (TEM), dynamic light scattering (DLS), and X-ray photoelectron spectroscopy (XPS) methods. These nanoparticles were also evaluated in vitro for their antimalarial activity against Plasmodium falciparum (3D7 strain) with an IC50 value of 0.0021 μM and showed low toxicity to Uppsala 87 malignant glioma (U87MG) cell lines, malignant melanoma A375 cell lines, KB human oral cancer cell lines, rat cortical neuron cell lines, and rat fibroblast-like synoviocyte (FLS) cell lines.

PfMDR1 Transport Rates Assessed in Intact Isolated Plasmodium falciparum Digestive Vacuoles Reflect Functional Drug Resistance Relationship with pfmdr1 Mutations.

Drug resistance often emerges from mutations in solute transporters. Single amino acid exchanges may alter functionality of transporters with ‘de novo’ ability to transport drugs away from their site of action. The PfMDR1 transporter (or P-glycoprotein 1) is located in the membrane of the digestive vacuole (DV), functions as an ATP-dependent pump, and transports substrates into the DV. In this study, four strains of Plasmodium falciparum, carrying various pfmdr1 gene mutations, were analysed for their transport characteristics of Fluo-4 in isolated DVs of parasites. To obtain quantitative estimates for PfMDR1 DV surface expression, PfMDR1 protein amounts on each strain’s DV membrane were evaluated by quantitative ELISA. Fluo-4, acting as a substrate for PfMDR1, was applied in DV uptake assays (‘reverse Ca2+ imaging’). Viable DVs were isolated from trophozoite stages with preserved PfMDR1 activity. This newly developed assay enabled us to measure the number of Fluo-4 molecules actively transported into isolated DVs per PfMDR1 molecule. The drug-resistant strain Dd2 presented the highest transport rates, followed by K1 and the drug-sensitive strain 3D7, compatible with their copy numbers. With this assay, an evaluation of the probability of resistance formation for newly developed drugs can be implemented in early stages of drug development.

In vitro Evaluation and Molecular Dynamics, DFT Guided Investigation of Antimalarial Activity of Ethnomedicinally used Coptis teeta Wall.

Malaria is caused by different species of Plasmodium; among which P. falciparum is the most severe. Coptis teeta is an ethnomedicinal plant of enormous importance for tribes of northeast India. In this study, the antimalarial activity of the methanol extracts of Coptis teeta was evaluated in vitro and lead identification was carried out via in silico study. On the basis of the in vitro results, in silico analysis by application of different modules of Discovery Studio 2018 was performed on multiple targets of P. falciparum taking into consideration some of the compounds reported from C. teeta. The IC50 of the methanol extract of Coptis teeta was reported to be 0.08 μg/ml in 3D7 strain and 0.7 μg/ml in Dd2 strain of P. falciparum. From the docking study, noroxyhydrastatine was observed to have better binding affinity in comparison to chloroquine. The binding of noroxyhydrastinine with dihydroorotate dehydrogenase was further validated by molecular dynamics simulation and was observed to be significantly stable in comparison to the co-crystal inhibitor. During simulations, it was observed that noroxyhydrastinine retained the interactions, giving strong indications of its effectiveness against the P. falciparum proteins and stability in the binding pocket. From the Density-functional theory analysis, the bandgap energy of noroxyhydrastinine was found to be 0.186 Ha, indicating a favorable interaction. The in silico analysis as an addition to the in vitro results provides strong evidence of noroxyhydrastinine as an antimalarial agent.

Total phenolic and flavonoid contents, antioxidant, antidiabetic and antiplasmodial activities of Garcinia forbesii King: A correlation study

Garcinia forbesii King belongs to Clusiaceae is a source of secondary metabolites especially xanthones with various biological activities. G. forbesii King is also known for its empirical use for malaria and diabetes. This study investigated the total phenolic and flavonoid contents, in vitro antioxidant, antidiabetic and antiplasmodial activities of four extracts attained from the stem bark of G. forbesii King. The total phenolic and flavonoid contents were determined by spectrophotometric methods and antioxidant activity was evaluated by DPPH, ABTS, FRAP assays. In vitro antidiabetic activity was assessed by α-glucosidase and α-amylase assays and antiplasmodial activity was studied against chloroquine sensitive Plasmodium falciparum strain 3D7. The highest value of total phenolic (187.37 ± 0.06 mg GAE/g) and flavonoid (35.97 ± 0.02 mg QE/g) contents were recorded in n-hexane and methanolic extracts. n-Hexane extract showed the highest DPPH activity with IC50 of 8.12 ± 0.02 μg/mL. Ethyl acetate extract exhibited better scavenging ability for ABTS with IC50 of 3.88 ± 0.04 μg/mL. The FRAP assay showed better activity in methanol extract with an inhibition value of 73.68 ± 3.66 µM Fe2+/g. The strong inhibition against α-glucosidase and α-amylase were displayed by dichloromethane extract with IC50 of 35.13 ± 2.01 μg/mL and 4.83 ± 0.20 μg/mL. n-Hexane and methanol extracts showed significant antiplasmodial activity with IC50 of 0.23 ± 0.01 μg/mL and 0.73 ± 0.01 μg/mL, respectively. The correlation analysis indicated a positive relationship of total phenolic and flavonoid contents with antiplasmodial activity. The results revealed that n-hexane and methanol extracts could be used as a potential natural antiplasmodial, while dichloromethane extract is a promising natural antidiabetic.

Response mechanism of psychrotolerant Bacillus cereus D2 towards Ni (II) toxicity and involvement of amino acids in Ni (II) toxicity reduction

The toxic effect of Nickel (Ni (II)) on humans and animals has been previously addressed. Owing to the important application of psychrotolerant bacteria in Ni (II) damage remediation in contamination sites at low temperatures, the response mechanism of psychrotolerant bacteria to Ni (II) toxicity must be elucidated. Therefore, the effect of Ni (II) toxicity on a psychrotolerant Bacillus cereus D2 was studied, showing a way to alleviate the Ni (II) toxicity in strain D2. The results showed that strain D2 growth was completely inhibited at a concentration of 100 mg/L of Ni (II). The main effects of Ni (II) toxicity on strain D2 were membrane damage and reactive oxygen species-dependent oxidative stress. Additionally, Ni (II) toxicity resulted in dysregulation of the cell cycle in strain D2. Furthermore, metabolomic analysis showed that the biosynthesis of amino acids and ABC transporters were significantly affected, and the relative abundance of seven important amino acids changed in a concentration-dependent manner. Addition of 20 mM or 5 mM amino acids to 100 mg/L Ni (II)-treated strain D2 restored its growth. This study provides insights into the way to alleviate the Ni (II) toxicity in strain D2, thus contributing to the development of bioremediation strategies.

A new C–C linked benzophenathridine–2-quinoline dimer, and the antiplasmodial activity of alkaloids from Zanthoxylum holstzianum

The CH2Cl2/MeOH (1:1) extract of Zanthoxylum holstzianum stem bark showed good antiplasmodial activity (IC50 2.5 ± 0.3 and 2.6 ± 0.3 µg/mL against the W2 and D6 strains of Plasmodium falciparum, respectively). From the extract five benzophenanthridine alkaloids [8-acetonyldihydrochelerythrine (1), nitidine (2), dihydrochelerythine (3), norchelerythrine (5), arnottianamide (8)]; a 2-quinolone alkaloid [N-methylflindersine (4)]; a lignan [4,4′-dihydroxy-3,3′-dimethoxylignan-9,9′-diyl diacetate (7)] and a dimer of a benzophenanthridine and 2-quinoline [holstzianoquinoline (6)] were isolated. The CH2Cl2/MeOH (1:1) extract of the root bark afforded 1, 3–6, 8, chelerythridimerine (9) and 9-demethyloxychelerythrine (10). Holstzianoquinoline (6) is new, and is the second dimer linked by a C-C bond of a benzophenanthridine and a 2-quinoline reported thus far. The compounds were identified based on spectroscopic evidence. Amongst five compounds (1-5) tested against two strains of P. falciparum, nitidine (IC50 0.11 ± 0.01 µg/mL against W2 and D6 strains) and norchelerythrine (IC50 value of 0.15 ± 0.01 µg/mL against D6 strain) were the most active.

Investigating the antiplasmodial activity of substituted cyclopentadienyl rhodium and iridium complexes of 2-(2-pyridyl)benzimidazole

Six cationic half-sandwich Ir(III) and Rh(III) complexes (C1-C6) were synthesised by reaction of 2-(2-pyridyl)benzimidazole with the appropriate chloro-bridged dimers. All complexes were fully characterised using standard spectroscopic techniques and their purity confirmed by RP-HPLC. The molecular structures of these complexes were elucidated using single-crystal X-ray diffraction. Depending on the substituted cyclopentadienyl (Cpx) ligands, the complexes crystallized with an orthorhombic (Cpx = pentamethylcyclopentadienyl), monoclinic (Cpx = tetramethylphenylcyclopentadienyl) or triclinic (Cpx = tetramethylbiphenylcyclopentadienyl) crystal system. All complexes displayed good solubility in PBS and HEPES buffers within the concentration range used for the in vitro inhibitory screening. Using proton NMR experiments, the stability of the complexes in water was monitored at 37 °C and all complexes were resistant to displacement of their chlorido ancillary ligands by water. In vitro screening against the 3D7 chloroquine-sensitive and Dd2 multi-drug-resistant strains of Plasmodium falciparum revealed all complexes exhibited moderate to good potency. Complex C6 emerged as the most promising candidate with IC50 values of 0.75 ± 0.11 and 0.42 ± 0.055 µM against the 3D7 and Dd2 strains, respectively. The newly synthesised complexes were not cytotoxic to Human Embryonic Kidney cells.

Differential priority effects impact taxonomy and functionality of host-associated microbiomes.

Most multicellular eukaryotes host complex communities of microorganisms, but the factors that govern their assembly are poorly understood. The settlement of specific microorganisms may have a lasting impact on community composition, a phenomenon known as the priority effect. Priority effects of individual bacterial strains on a host's microbiome are, however, rarely studied and their impact on microbiome functionality remains unknown. We experimentally tested the effect of two bacterial strains (Pseudoalteromonas tunicata D2 and Pseudovibrio sp. D323) on the assembly and succession of the microbial communities associated with the green macroalga Ulva australis. Using 16S rRNA gene sequencing and qPCR, we found that both strains exert a priority effect, with strain D2 causing initially strong but temporary taxonomic changes and strain D323 causing weaker but consistent changes. Consistent changes were predominately facilitatory and included taxa that may benefit the algal host. Metagenome analyses revealed that the strains elicited both shared (e.g., depletion of type III secretion system genes) and unique (e.g., enrichment of antibiotic resistance genes) effects on the predicted microbiome functionality. These findings indicate strong idiosyncratic effects of colonizing bacteria on the structure and function of host-associated microbial communities. Understanding the idiosyncrasies in priority effects is key for the development of novel probiotics to improve host condition.

Structure-activity and structure-property relationship studies of spirocyclic chromanes with antimalarial activity

Malaria is a prevalent and lethal disease. The fast emergence and spread of resistance to current therapies is a major concern and the development of a novel line of therapy that could overcome, the problem of drug resistance, is imperative. Screening of a set of compounds with drug/natural product-based sub-structural motifs led to the identification of spirocyclic chroman-4-one 1 with promising antimalarial activity against the chloroquine-resistant Dd2 and chloroquine-sensitive 3D7 strains of the parasite. Extensive structure-activity and structure-property relationship studies were conducted to identify the essential features necessary for its activity and properties.

Solid Dispersion of Lumefantrine Using Soluplus® by Solvent Evaporation Method: Formulation, Characterization and in-vitro Antimalarial Screening

Abstract: Objectives: Lumefantrine (LUM) is an antimalarial drug having poor aqueous solubility. The objective was to formulate the solid dispersion of LUM and improve the solubility and dissolution rate. Materials and Methods: Solvent evaporation technique was used to prepare solid dispersions (SDs) with Soluplus® (SOL) using a rotary evaporator. The feasibility of the formation of SD for LUM and SOL was assessed by the Hansen solubility parameter. The drug solubility was analyzed by the HPLC method and the ratio of LUM: SOL was optimized to 1:2. The SD was characterized by DSC, FTIR, XRD and SEM. Results: The results showed that the LUM and SOL had groups that lead to the interaction between them and this led to conversion from crystalline to amorphous form and thus improved the dissolution rate. The solubility of L2 was found to be 135 ± 3.3 μg/mL using the selected dissolution media (0.1 N HCl+1% Myrj 52). The in-vitro antimalarial screening was performed using the P. falciparum 3D7 strain and the in-vitro cytotoxicity test was performed using the Vero cell line. The higher antimalarial efficacy of L2 SD was observed as compared to plain LUM. The selectivity index value of LUM SD depicted its non-toxicity. Stability study was carried out for three months and the SDs were evaluated for the drug content, change in weight and in-vitro drug release. No significant changes were observed after three months in the drug content, SD weight and in-vitro drug release. Thus the L2 SD was found to be stable. Conclusion: The prepared SD improved the solubility as well as the dissolution rate of the drug. Key words: Lumefantrine, Soluplus, Solubility enhancement, Dissolution rate, Antimalarial screening. Key words: Lumefantrine, Soluplus, Solubility enhancement, Dissolution rate, Antimalarial screening.

Microbial production of hydroxy fatty acids utilizing crude glycerol

Strain D2 was isolated from a natural sample as a crude glycerol-assimilating microorganism. The ITS-5.8S rDNA sequence of strain D2 was most similar to that of Fusarium solani deposited in the NCBI database. Strain D2 accumulated 10-hydroxy-cis-12-octadecenoic acid (HYA), 10-hydroxyoctadecanoic acid (HYB), and 10-oxooctadecanoic acid (KetoB) in a medium containing crude glycerol, as a carbon source, and yeast extract, named CG medium. The growth and HYB production of strain D2 depended on the crude glycerol concentration in the medium. Strain D2 produced 2.20 g/L (40% of total fatty acids) of HYB on cultivation in CG medium containing 8% crude glycerol. When strain D2 was cultivated in CG medium containing 6% crude glycerol, the yield of HYB on cultivation under 4 days-shaking and 3 days-static conditions reached 1.19 g/L, which was 2.2 times higher than that under 7 days-shaking conditions and accounted for 53% of total fatty acids. The fungus was found not only to efficiently produce fatty acids utilizing crude glycerol, but also to be the first filamentous fungus to produce hydroxy and oxo fatty acids such as HYB, HYA, and KetoB.

ТЕХНОЛОГИЯ ИЗГОТОВЛЕНИЯ ЭНЕРГЕТИЧЕСКИ АКТИВНОЙ ЭКОДОБАВКИ С ИСПОЛЬЗОВАНИЕМ ПРИРОДНЫХ, МИНЕРАЛЬНЫХ И БАКТЕРИАЛЬНЫХ РЕСУРСОВ

The article deals with the problem of soil salinization, focuses on the problem of deterioration of soil fertility and the quality of agricultural land. The technology of manufacturing an energetically active eco-additive is proposed, which includes lactobacilli, salt-resistant bacteria of the Caspian Sea, nitrogen-forming bacteria and bacteria obtained from rainwater (strain D1) related to saprophytic bacteria. A technology of production of an energy-active eco additive is also proposed, which, in addition to saprophytic microbes and unicellular algae, includes calcined algae, sulfur and biomass of plant origin (waste), which are a source of alternative energy. The use of the last component of eco additive has a detrimental effect on pathogenic fungi and a positive effect on bacteria and algae. This makes it possible to widely use eco-additive in saline lands and greenhouses to combat pathogenic fungi and aridity, in addition, it contributes to an increase in the number of bacteria in the soil that contribute to the rapid decomposition of chemical minerals and also increase soil fertility.

Antiplasmodial Activity of Griffipavixanthone and Morelloflavone the Main Compounds from Garcinia Chromocarpa Engl. (Clusiaceae)

Ethnopharmacological relevance: The genus Garcinia is a rich source of species mostly used in traditional medicine to treat a many diseases. Bioactive constituents from this genus have been used as antimicrobial, anticancer, antimalarial, anti-inflammatory, hepatoprotective and anti-HIV. According to these properties, major compounds of this plant have been evaluated for their antiplasmodial activity. Materials and methods: The methanol extract of the G. chromocarpa stem bark was used in this study. The chromatographic fractionation of this latest led to the isolation of two major compounds, identified by NMR and MS spectroscopic techniques. The crude extract and pure compounds were compared using the in vitro evaluation of the malaria parasite growth inhibition by colorimetric method (p-LDH assay). Furthermore ABTS•+ and DPPH• scavenging activities and cytotoxicity through WST1 assay were evaluated. Results: Based on the chromatographic profile two major compounds were isolated. They were characterized by spectroscopic analysis interpretation and comparison with the data in the literature: one biflavonoid (1) and one xanthone (2). The compound 2 (Griffipavixanthone, IC50 ± S.D = 5.80±0.32 μg/mL) was found to be more active against the malaria parasite, chloroquinesensitive (3D7) strain of P. falciparum, than the compound 1 (Morelloflavone, IC50 ± S.D = 9.20±0.96 μg/mL). The antiradical activities connected to the ability to scavenge free radicals were observed for the ethanol crude extract of the stem bark, and the leave of G. chromocarpa. Conclusions: This work demonstrated for the first time the antiplasmodial activity of G. chromocarpa and its isolated major compounds. These latest are known in the genus Garcinia but, here, firstly described in G. chromocarpa Engl.

Update and elucidation of Plasmodium kinomes: Prioritization of kinases as potential drug targets for malaria

Malaria is a tropical disease caused by Plasmodium spp. and transmitted by the bite of infected Anopheles mosquitoes. Protein kinases (PKs) play key roles in the life cycle of the etiological agent of malaria, turning these proteins attractive targets for antimalarial drug discovery campaigns. As part of an effort to understand parasite signaling functions, we report the results of a bioinformatics pipeline analysis of PKs of eight Plasmodium species. To date, no P. malariae and P. ovale kinome assemble has been conducted. We classified, curated and annotated predicted kinases to update P. falciparum, P. vivax, P. yoelii, P. berghei, P. chabaudi, and P. knowlesi kinomes published to date, as well as report for the first time the kinomes of P. malariae and P. ovale. Overall, from 76 to 97 PKs were identified among all Plasmodium spp. kinomes. Most of the kinases were assigned to seven of nine major kinase groups: AGC, CAMK, CMGC, CK1, STE, TKL, OTHER; and the Plasmodium-specific group FIKK. About 30% of kinases have been deeply classified into group, family and subfamily levels and only about 10% remained unclassified. Furthermore, updating and comparing the kinomes of P. vivax and P. falciparum allowed for the prioritization and selection of kinases as potential drug targets that could be explored for discovering new drugs against malaria. This integrated approach resulted in the selection of 37 protein kinases as potential targets and the identification of investigational compounds with moderate in vitro activity against asexual P. falciparum (3D7 and Dd2 strains) stages that could serve as starting points for the search of potent antimalarial leads in the future.

Isolation of Antimalarial Agents From Indonesian Medicinal Plants:Swietenia mahagoniandPluchea indica

Malaria is a neglected tropical disease that still demands serious efforts to tackle successfully, including the need for new antimalarial lead compounds to combat drug-resistant Plasmodium. Intensive phytochemical and pharmacological investigation into the Indonesian medicinal plants Swietenia mahagoni and Pluchea indica successfully revealed 5 constituents. Antimalarial bioassays indicated 34,5-tri- O-caffeoylquinic acid (4) to be the most active against Plasmodium falciparum 3D7 and Dd2 strains with IC50values of 8.2 and 8.8 µM, respectively. No cytotoxicity was observed against Human Embryonic Kidney cells at a concentration of 40 µM.

Synthesis and initial testing of novel antimalarial and antitubercular isonicotinohydrazides

Malaria and tuberculosis (TB) though curable and preventable, remain serious public health problems globally, with devastating consequences. Co-infection of these two deadly diseases worsens the situation and particularly makes treatment very difficult. The current mainstay for malaria treatment is gradually losing their potency due to the development of resistance. Macobacterium tuberculosis (MTB) has developed Multi-drug Resistance (MDR) and Extensive Drug Resistance (XDR) to current antitubercular drugs due to patient incompliance resulting from long treatment regimen. A small library of isonicotinohydrazide were synthesised by incorporating 1,2,4,5- tetraoxane and hydrazine moieties. Evaluation of the compounds gave antimalarial activities in the range 0.060 ± 0.033–0.491 ± 0.012 µM against 3D7 strain of Plasmodium falciparum. We assessed antimycobacterial activity of selected compounds against the standard Mycobacterium tuberculosis reference strain H37Rv and M. aurum (a non-tuberculous mycobacteria) using the microplate Alamar blue (MABA) assay and found four compounds to be very potent against H37Rv but largely inactive against Macobacterium aurum. We followed up to estimate the minimum inhibitory concentrations of these active compounds and tested them against clinical M. tuberculosis strains resistant to isoniazid (INH) and rifampicin (RIF). The MICs of the active compounds against H37Rv were between 0.003 and 0.5 mg/mL however, they were largely inactive against drug resistant clinical strains except for the INH mono-resistant resistant strain which was very active with compounds 5 and 8 possessing MICs of 0.125 mg/mL.

English

In the crude extracts of the bark and leaves of Sclerocarya birrea, have been characterized sterols, triterpenes, saponosides, tannins, anthocyanosides, coumarins, reducing compounds, alkaloids and carotenoids. Tests were carried out in vitro with extracts from each part of the plant to assess their efficacy against strains of Plasmodium falciparum sensitive to chloroquine K1 and that resistant to chloroquine 3D7. The crude alkaloidal extracts of the bark gave IC50 = 2.54 μg / ml with the strain 3D7 and an IC50 = 4.09 μg / ml with the strain K1. On the other hand, the extracts with CH2Cl2 showed an IC50 = 36.59 and 37.78 μg / ml respectively with the 3D7 and K1 strains. Those with CH3OH gave IC50 all greater than 50 μg/ml with both strains. The CH3OH / H2O extracts gave IC50 = 21.48 μg / ml with the K1 strain and greater than 50 μg / ml with 3D7. As for the H2O extracts, the IC50 were = 11.43 μg / ml with the K1 strain and also greater than 50 μg / ml with the 3D7. The alkaloid extracts of leaf gave an IC50 = 9.68 µg / ml with 3D7 and = 3.56 µg / ml with strain K1. With CH2Cl2, and IC50 = 6.62 μg / ml was obtained with 3D7 and 4.05 μg / ml with strain K1. The CH3OH extracts gave an IC50 = 21.12 μg / ml with the 3D7 strain and 21.06 μg / ml with the KI strain. The CH3OH / H2O extracts gave with strain 3D7 and IC50 of more than 50 and 32.73 μg / ml with K1. The aqueous extracts gave IC50 greater than 50 μg / ml for 3D7 and 25.17 μg / ml with the K1 strain. Key words: Medicinal plants, Niger, Sclerocarya birrea, Malaria, Antiplasmodial activity, Alkaloids, Dichloromethane.