In vivo antimalarial activity of self-nanoemulsifying drug delivery systems containing ethanolic extract of Morinda lucida in combination with other Congolese plants extracts

Morinda lucida leaves are largely used by Congolese traditional healers for the treatment of uncomplicated malaria. The antimalarial activity of their ethanolic extract has been confirmed both in vitro and in vivo. However, the development of relevant formulations for potential clinical application is hampered since the active ingredients contained in this extract exhibit poor water solubility and low oral bioavailability. Hence, this work aims not only to develop self-nanoemulsifying drug delivery systems (SNEDDSs) for oral delivery of the ethanolic extract of Morinda lucida (ML) but also to evaluate its oral antimalarial activity alone and in combination with other Congolese ethanolic plant extracts (Alstonia congensis, Garcinia kola, Lantana camara, Morinda morindoides or Newbouldia laevis). Based on the solubility of these different extracts in various excipients, SNEDDS preconcentrates were prepared, and 200 mg/g of each plant extract were suspended in these formulations. The 4-day suppressive Peter’s test revealed a significant parasite growth inhibiting effect for all the extract-based SNEDDS (from 55.0 to 82.4 %) at 200 mg/kg. These activities were higher than those of their corresponding ethanolic suspensions given orally at the same dose (p<0.05). The combination therapy of MLSNEDDS with other extract-based SNEDDS exhibited remarkable chemosuppression, ranging from 74.3 % to 95.8 % (for 100 + 100 mg/kg) and 86.7 % to 95.5 % (for 200 + 200 mg/kg/day). In regard to these findings, SNEDDS suspension may constitute a promising approach for oral delivery of ML alone or in combination with other antimalarial plants

Resistance profiles of urinary Escherichia coli and Klebsiella pneumoniae isolates to antibiotics commonly prescribed for treatment of urinary tract infections at Monkole Hospital Center, Kinshasa, Democratic Republic of the Congo

Background: The occurrence of urinary tract infection (UTI) caused by multi-drug resistant bacteria is increasing worldwide and has become a major public health concern that requires global attention. To promote better treatment outcome of UTI and raise awareness of antibiotic resistance in the Democratic Republic of the Congo (DRC), we investigated the antimicrobial resistance profile of bacterial pathogens frequently isolated from urine samples of inpatients and outpatients with symptoms of UTI at the Monkole Hospital Center (MHC), Kinshasa from June 2017 to May 2018. Methodology: This was a retrospective review of results of uro-cultures of urine samples of both inpatients and outpatients who had clinical symptoms of UTI, over a period of one year at the MHC, Kinshasa, DRC. During this period, aerobic uro-cultures of urine were done on MacConkey agar (MAC) or Cystine-Lactose- Electrolyte-Deficient (CLED) agar media at 37oC incubation for 24 hours. Identification of bacterial isolates on the culture media and antimicrobial susceptibility to sixteen selected antibiotics were done using the integral system enterobacteria and the Vitek® 2 automated system according to the manufacturer’s instructions. The R-studio software was used for statistical analysis. Results: Of the 2765 uro-cultures performed during the period of study, 809 (29.3%) were positive for bacteria with Escherichia coli being the most frequently isolated bacteria pathogens. There was no significant difference (p>0.05) in the resistance rates of both E. coli and Klebsiella pneumoniae to most of the antibiotics such as amoxicillin-clavulanic acid, piperacillin-tazobactam, amikacin, levofloxacin, norfloxacin, cefuroxime, cefotaxime, cefixime and cephalexin but resistance rates of E. coli compared to K. pneumoniae was significantly higher to cotrimoxazole (OR=2.06, p=0.0016), ofloxacin (OR=3.43, p=0.0019), ciprofloxacin (OR=1.624, p=0.044) and significantly lower to imipenem (OR=0.037, p=0.0046), nitrofurantoin (OR=0.292, p=0.0004) and fosfomycin (OR=0.311, p=0.0003). Both pathogens showed resistance rates of more than 50.0% to doxycycline, cefuroxime, cefixime and cephalexin but resistance rates of K. pneumoniae to ofloxacin and cotrimoxazole was less than 50.0%. The isolates were least resistant to imipenem, piperacillin-tazobactam and amikacin, with less than 13.0% resistance rate. Conclusion: The findings of this study showed that E. coli is the most isolated bacterial uro-pathogen amongst patients with UTI at MHC Kinshasa, DRC, but both E. coli and K. pneumoniae were resistant to most commonly prescribed antibiotics used for treatment of UTI. Amikacin, piperacillin-tazobactam and imipenem demonstrated high invitro activity and should be prioritized for antimicrobial stewardship to prevent or delay emergence of resistance to them. To guarantee optimal treatment of UTI, regular pathogen surveillance and local antibiogram reporting are required. Further studies are needed in DRC to assess the burden and factors driving antimicrobial resistance nationwide

Profilage phytochimique par chromatographie sur couche mince haute performance d’extraits de flavonoïdes totaux du Drepanoalpha® et évaluation de leur activité anti-drépanocytaire in vitro

Contexte et objectif. Le défi le plus important dans la drépanocytose consiste à améliorer l’état de santé des patients dans les pays en développement. L'une des meilleures solutions est donc le développement de la phytomédecine basée sur la connaissance de la pharmacopée traditionnelle. L’objectif de la présente étude était d’évaluer les activités anti-drépanocytaires des flavonoïdes totaux extraits du phytomédicament Drépanoalpha® d’une part et déterminer leur profilage chimique par chromatographie sur couche mince haute performance d’autre part. Méthodes. Les flavonoïdes totaux ont été obtenus par fractionnement de l’extrait méthanolique par chromatographie flash (PURIFLASH COLUMN 30 SILICA HP - 12,0 g) et purifies à l’aide d’une cartouche (Polymeric Reversed Phase) puis caractérisés et dosés par chromatographie sur couche mince haute performance (CCMHP). L’activité anti-drépanocytaire a été mise en évidence grâce aux tests d’Emmel, de polymérisation, de rapport Fe2+/Fe3+, d’hémolyse et de la fragilité osmotique membranaire. Résultats. La poudre du Drépanoalpha® contenait une quantité de flavonoïdes totaux de 8,14 mg équivalent de quercétine/g d'extrait. Les flavonoïdes totaux extraits du Drépanoalpha® possèdent une activité antifalcémiante (avec le taux maximal de normalisation d’environ 90 % et une concentration minimale de normalisations de 11,4 μg/mL), un taux d’augmentation du rapport Fe2+/Fe3+ de 97,0 %, une activité anti-hémolytique avec une fragilité corpusculaire membranaire des érythrocytes (FCM) de 0,73 et un taux d’inhibition de la polymérisation de 77,5%. Conclusion. La pertinence des résultats de cette étude permet de confirmer les flavonoids comme phytomarqueur pour le contrôle de qualité et de standardisation de cet alicament. English Title: In vitro evaluation of anti-sickling activity of crude flavonoid extracted from Drepanoalpha® and their phytochemical profiling by high performance thin layer chromatography Abstract Context and objective. The most important challenge in Sickle cell disease is to improve the health status of patients in developing countries. One of the best solutions is the development of phytomedicine based on the knowledge of the traditional pharmacopoeia. This study aimed to evaluate the anti-sickling activities of crude flavonoids extracted from the phytomedicine Drépanoalpha® on the one hand and to determine their chemical profiling by high performance thin layer chromatography on the other hand. Methods. Crude flavonoids were obtained by fractionation of the methanolic extract by flash chromatography (PURIFLASH COLUMN 30 SILICA HP - 12.0 g) and purified using a cartridge (Polymeric Reversed Phase) then characterized and assayed by high performance thin layer chromatography (HPTLC). The anti-sickling activity was carried out using Emmel, polymerization, Fe2+/Fe3+ ratio, hemolysis and membrane osmotic fragility tests. Results. Drepanoalpha® powder contained an amount of total flavonoids of 8.14 mg quercetin eq/g extract. The total flavonoids extracted from Drépanoalpha® have an antisickling activity (with a maximum reversibility rate of about 90% and a minimum reversibility concentration of 11.4 μg/mL), an increase rate of the Fe2+/Fe3+ ratio of 97.0%, an antihemolytic activity with a corpuscular membrane fragility of erythrocytes (FCM) of 0.73 and a polymerization inhibition rate of 77.5%. Conclusion. Findings from the present study confirm flavonoids as a phytomarker for the quality control and standardization of Drépanoalpha®. Keywords: Drépanoalpha®, Sickle cell disease, Hemoglobin S, Polymerization, Methemoglobin, Flavonoid

Current Advances in Lipid Nanosystems Intended for Topical and Transdermal Drug Delivery Applications

peer reviewedSkin delivery is an exciting and challenging field. It is a promising approach for effective drug delivery due to its ease of administration, ease of handling, high flexibility, controlled release, prolonged therapeutic effect, adaptability, and many other advantages. The main associated challenge, however, is low skin permeability. The skin is a healthy barrier that serves as the body’s primary defence mechanism against foreign particles. New advances in skin delivery (both topical and transdermal) depend on overcoming the challenges associated with drug molecule permeation and skin irritation. These limitations can be overcome by employing new approaches such as lipid nanosystems. Due to their advantages (such as easy scaling, low cost, and remarkable stability) thesesystems have attracted interest from the scientific community. However, for a successful formulation, several factors including particle size, surface charge, components, etc. have to be understood and controlled. This review provided a brief overview of the structure of the skin as well as the different pathways of nanoparticle penetration. In addition, the main factors influencing the penetration of nanoparticles have been highlighted. Applications of lipid nanosystems for dermal and transdermal delivery, as well as regulatory aspects, were critically discussed

In Vitro Biological Activities of Drepanoalpha® Ethanolic Extract, A Justicia Secunda and Moringa Oleifera-Based Phytomedicine Proposed for The Symptomatic Treatment of Sickle Cell Disease

Sickle cell disease (SCD) is an autosomal recessive blood disorder characterized by red blood cells that assume an abnormal, rigid sickle shape under low-oxygen conditions. These sickle-shaped erythrocytes tend to lyse, aggregate, and obstruct small blood vessels, leading to major complications. The present study aims to investigate properties that may underlie the activity of Drepanoalphaâ, an antisickling herbal formulation developed in the Democratic Republic of Congo (DRC) for the prevention and symptomatic treatment of sickle cell disease crises. The Drepanoalpha® Ethanolic Extract (DEE) is a dry extract (drug-extract ratio, DER, 100/11) prepared from ethanol (96 %, v/v) percolation of a 1:1 mixture of 2 food plants, Justicia secunda Vahl and Moringa oleifera Lam. Sickling was classically measured by light microscopy on diluted washed erythrocytes obtained from homozygote patients; erythrocytes were treated with 2 % Na2S2O5 in the presence of DEE (suspension in 9 ‰ NaCl), 9 ‰ NaCl (negative control) or disodium cromoglycate (DSCG, positive control). For all tested conditions, the sickle hemoglobin polymerization, the Fe2+/Fe3+ ratio, and the median corpuscular fragility were measured by spectrophotometry. The DEE reversed sickling by 89.1 %, comparable to DSCG (87.7 %; 60.3 µg/mL), inhibiting sickle cell hemoglobin polymerization of 77.8 % and 74.4 %, respectively. The Fe2+/Fe3+ ratio was improved by 18.0 % for DEE and 15.9 % for DSCG. The median corpuscular fragility values were 0.602, 0.714, and 0.732 for NaCl 9 ‰, DSCG, and DEE, respectively. The measured in vitro parameters validate an effective antisickling effect of DEE and confirm the value of this improved traditional herbal formulation for the management of SCD

Green synthesis of antimicrobial silver nanoparticles using aqueous leaf extracts from three Congolese plant species (Brillantaisia patula, Crossopteryx febrifuga and Senna siamea)

In the present study, silver nanoparticles (AgNPs) were synthesized using aqueous leaf extracts of three Congolese plant species, namely Brillantaisia patula (BR-PA), Crossopteryx febrifuga (CR-FE) and Senna siamea (SE-SI). The obtained AgNPs were studied for their optical, structural, surface morphological and antibacterial properties. The prepared AgNPs were characterized by using UV-Visible spectra, Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray spectroscopy (EDX) and X-ray diffractometer (XRD). The synthesized nanoparticles were spherical shaped and well-dispersed with average sizes ranging from 45 to 110 nm. The AgNPs derived from BR-PA, CR-FE and SE-SI exhibited higher antibacterial activity against three bacterial pathogens of the human skin compared to their respective crude extracts and AgNO3. This indicated that the biomolecules covering the nanoparticles may enhance the biological activity of metal nanoparticles. Hence, our results support that biogenic synthesis of AgNPs from Congolese plants constitutes a potential area of interest for the therapeutic management of microbial diseases such as infectious skin diseases

Medicinal plants with antimicrobial, larvicidal, and repellent properties: An ethnopharmacological survey from the Democratic Republic of the Congo

Introduction Infectious diseases (IDs) constitute a real public health problem in the Democratic Republic of the Congo (DRC). Purpose This survey aimed to gather more information about the plants used in the DRC for anti-infective, larvicidal, or repellent treatments. Methods The study spanned 4 months (from April 1 to July 31, 2022) within 11 provinces in the DRC and was conducted among 20 traditional healers (TH), 105 vegetable growers (VG), and 953 other plant users (OU) of traditional plants scattered across the country. The survey consisted of a simple interview with an inventory of the plants used. Results The results showed that the average age of the respondents was between 39 and 43 years old. The VG were mainly illiterate. As for TH and OU, literacy rates up to the primary level were 60% and 78%, respectively. The knowledge of the use of plants by the various actors of traditional medicine in this survey emanates from the cultural heritage. For this study, 132 plant species (104 identified and 28 unidentified based on their botanical name or family) were reported. 33 antimicrobial species and 7 larvicidal species belonging to 22 botanical families have been reported among TH, while 1 and 75 antimicrobial species, 6 and 16 larvicidal species, and 13 and 30 repellent species were respectively identified among VG and OU. This study identified Morinda morindoides, Cymbopogon citratus, and Boswellia sacra as the plant species most used by the individuals surveyed for anti-infective, larvicidal, and repellent treatments, respectively, by their citation frequencies, which were the highest. Additionally, the leaves represented the plant parts most used by the respondents. Conclusion This ethnobotanical analysis revealed that most herbal antimicrobial recipes are used to treat malaria. This study confirms the richness of the Congolese flora concerning anti-infective, larvicidal, and repellent treatments

Lipid-based formulations for oral delivery of poorly water-soluble antimalarial drugs

Malaria is the most prevalent parasitic disease and the foremost cause of morbidity and mortality in the world. Currently, the first-line treatment for malaria is based on the association of an artemisinin-type compound with another drug. β-arteether (AE), the ethyl ether derivative of artemisinin, is highly effective against all species of Plasmodium. Curcumin (CC), a hydrophobic polyphenol from Curcuma longa, was recently proposed as one of the adjunctive therapy strategies in the AE-combination therapies to protect against parasite recrudescence and relapse. However, the oral delivery of AE and CC is limited by their poor water solubility and low stability in gastrointestinal medium. The main objective of this thesis was to develop lipid-based drug delivery systems (LBDDS) for the oral delivery of AE and CC in order to enhance their oral bioavailability and to provide an effective rapid cure for malaria at low cost. In the gastrointestinal medium, the developed LBDDS self-emulsified and increased the solubility and the stability of AE and CC. Additionally, AE-LBDDS and CC-LBDDS significantly increased the transport of AE and CC across intestinal cell monolayers. Using murine malaria model, complete cure was observed in mice treated orally with AE-LBDDS at 24 mg/kg for 4 days. At the same dose, this antimalarial efficacy was comparable to that of the marketed intramuscular injectable formulations of AE and significantly higher than that of an oily solution of AE given orally. The combination therapy of subtherapeutic dose of AE-LBDDS and CC-LBDDS increased protection and survival rate associated with a significant delay in recrudescence. In conclusion, the combination of oral AE and CC loaded in LBDDS may constitute a promising approach for the treatment of malaria at low cost.(BIFA - Sciences biomédicales et pharmaceutiques) -- UCL, 201

Formulation design and in vivo antimalarial evaluation of lipid-based drug delivery systems for oral delivery of β-arteether

β-Arteether, an effective artemisinin derivative, is used in the treatment of malaria but available only as an intramuscular injection. The objective of this work was to develop lipid-based formulations for oral administration of β-arteether. Self-emulsifying drug delivery systems (SEDDSs) of low cost and with accessible excipients (groundnut or sesame oil, Maisine 35-1, Tween 80 or Cremophor EL, and absolute ethanol) were formulated. In 250 ml of simulated gastric medium, 1g of these SEDDS solubilized the daily dose of β-arteether and formed lipid droplets of average size 80-250 nm. No toxicity against Caco-2 intestinal cells was observed. Using a mouse model, the efficacy of these arteether lipid formulations against Plasmodium berghei was evaluated. A daily dose of 24 mg/kg for 4 days led to complete cure for more than 45 days in 100% of treated mice and had an antimalarial efficacy comparable to that of an intramuscular oily solution of arteether and significantly higher than that of an oily solution of β-arteether given orally at the same dose. In conclusion, lipid-based drug delivery systems constitute a promising approach for the oral administration of β-arteether

An oral malaria therapy: Curcumin-loaded lipid-based drug delivery systems combined with β-arteether.

Curcumin (CC), a potential antimalarial drug, has poor water solubility, stability and oral bioavailability. To circumvent these pitfalls, lipid-based drug delivery systems (LBDDSs) with a high CC loading (30mg/g) were formulated. In a biorelevant gastric medium, CC-LBDDSs formed particle sizes in the range of 30-40nm. During in vitro lipolysis, 90-95% of the CC remained solubilized, whereas 5-10% of the CC precipitated as an amorphous solid, with a high rate of re-dissolution in a biorelevant intestinal medium. The transport of the CC-LBDDS across Caco-2 monolayers was enhanced compared with the transport of free drug because of the increased CC solubility. In Plasmodium berghei-infected mice, modest antimalarial efficacy was observed following oral treatment with CC-LBDDSs. However, the combination therapy of CC-LBDDS with a subtherapeutic dose of β-arteether-LBDDS provided an increase in protection and survival rate that was associated with a significant delay in recrudescence. These findings suggest that the combination of oral CC and β-arteether lipid-based formulations may constitute a promising approach for the treatment of malaria