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Journal of Medicinal Food Jun 2024Malaria impedes the ability of primary cells of the immune system to generate an efficacious inflammatory and immune response. Black seed () is a core dietary supplement...
Malaria impedes the ability of primary cells of the immune system to generate an efficacious inflammatory and immune response. Black seed () is a core dietary supplement and food additive in folklore. This study investigated the antioxidant, immunomodulatory, and anti-inflammatory effects of cookies in -infected mice. Aqueous extract of black seed was prepared, and the total phenol and flavonoid contents were determined. The mice were infected with standard inoculum of the strain NK65 . The mice weight and behavioral changes were observed. The mice were fed with the cookies (2.5%, 5%, and 10%) and 10 mg/kg chloroquine for 5 consecutive days after the infection was established. The reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase, catalase, and hematological parameters (red cell indices, leukocytes, and its differentials) in the infected mice were determined. The inflammatory mediators, C-reactive protein (CRP), and myeloperoxidase (MPO) were also assayed. The result revealed that black seed had a total phenol content of 18.73 mgGAE/g and total flavonoid content of 0.36 mgQUE/g. The infected mice treated with cookies showed significantly decreased parasitaemia, MDA, and ROS levels. Furthermore, the results showed significant suppression in proinflammatory mediators (CRP and MPO) levels and enhanced antioxidant status of infected mice treated with . The study suggests that could function as nutraceuticals in the management of infection associated with inflammatory and immunomodulatory disorders.
Topics: Animals; Plasmodium berghei; Malaria; Oxidative Stress; Mice; Nigella sativa; Seeds; Plant Extracts; Male; Antioxidants; Disease Models, Animal; Reactive Oxygen Species; Malondialdehyde; Inflammation; Anti-Inflammatory Agents; Food, Fortified; C-Reactive Protein; Superoxide Dismutase; Humans; Flavonoids; Peroxidase
PubMed: 38935918
DOI: 10.1089/jmf.2023.0181 -
Parasitology Research Aug 2023This study investigated the effects of co-administration of a commercial juice rich in vitamin C (Vit C) on the antimalarial efficacy of artemether-lumefantrine (AL) in...
This study investigated the effects of co-administration of a commercial juice rich in vitamin C (Vit C) on the antimalarial efficacy of artemether-lumefantrine (AL) in Plasmodium berghei-infected mice. Fifty Balb/c mice were infected with Plasmodium berghei NK65 strain from a donor mouse. Parasitemia was established after 72 h. Animals were grouped into 6 (n = 10) and treated daily for 3 days with normal saline, chloroquine, artemether-lumefantrine (AL), AL plus 50% commercial juice (CJ), and AL plus 50% Vit C supplementation in drinks ad libitum, respectively. Body weight, parasitemia levels, and mean survival time were determined. Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), nitrite, malondialdehyde, reduced glutathione (GSH), catalase, and superoxide dismutase (SOD) were determined in the serum and liver tissues. Spleen histopathological changes were determined by H&E staining. Parasitemia was cleared by administration of AL and was not affected by Vit C and CJ supplementation. Vit C significantly prevented body weight reduction in AL-treated mice. CJ and Vit C supplementation to AL-treated mice significantly improved survival proportion compared with AL alone animals. Vit C and CJ supplementation significantly improved reduction of TNF-α, IL-6, and malondialdehyde, and increased GSH, CAT, and SOD in AL-treated mice. Spleen cell degeneration and presence of malaria pigment were reduced in AL-treated animals. The results suggest that ad libitum co-administration of commercial juice and vitamin C with artemether-lumefantrine does not impair its antimalarial efficacy but rather improved antioxidant and anti-inflammatory effects in mice.
Topics: Animals; Mice; Antimalarials; Artemether, Lumefantrine Drug Combination; Plasmodium berghei; Artemether; Malaria; Ascorbic Acid; Parasitemia; Interleukin-6; Tumor Necrosis Factor-alpha; Superoxide Dismutase; Malondialdehyde
PubMed: 37256314
DOI: 10.1007/s00436-023-07885-5 -
Nature Communications Jun 2024Differentiation of male gametocytes into flagellated fertile male gametes relies on the assembly of axoneme, a major component of male development for mosquito...
Differentiation of male gametocytes into flagellated fertile male gametes relies on the assembly of axoneme, a major component of male development for mosquito transmission of the malaria parasite. RNA-binding protein (RBP)-mediated post-transcriptional regulation of mRNA plays important roles in eukaryotic sexual development, including the development of female Plasmodium. However, the role of RBP in defining the Plasmodium male transcriptome and its function in male gametogenesis remains incompletely understood. Here, we performed genome-wide screening for gender-specific RBPs and identified an undescribed male-specific RBP gene Rbpm1 in the Plasmodium. RBPm1 is localized in the nucleus of male gametocytes. RBPm1-deficient parasites fail to assemble the axoneme for male gametogenesis and thus mosquito transmission. RBPm1 interacts with the spliceosome E complex and regulates the splicing initiation of certain introns in a group of 26 axonemal genes. RBPm1 deficiency results in intron retention and protein loss of these axonemal genes. Intron deletion restores axonemal protein expression and partially rectifies axonemal defects in RBPm1-null gametocytes. Further splicing assays in both reporter and endogenous genes exhibit stringent recognition of the axonemal introns by RBPm1. The splicing activator RBPm1 and its target introns constitute an axonemal intron splicing program in the post-transcriptional regulation essential for Plasmodium male development.
Topics: Introns; RNA Splicing; RNA-Binding Proteins; Animals; Protozoan Proteins; Male; Axoneme; Female; Gametogenesis; Spliceosomes; Plasmodium berghei; Malaria; Plasmodium
PubMed: 38824128
DOI: 10.1038/s41467-024-49002-9 -
ACS Infectious Diseases Jun 2024Our previous work identified a series of 12 xanthoquinodin analogues and 2 emodin-dianthrones with broad-spectrum activities against , , , and . Analyses conducted in...
Our previous work identified a series of 12 xanthoquinodin analogues and 2 emodin-dianthrones with broad-spectrum activities against , , , and . Analyses conducted in this study revealed that the most active analogue, xanthoquinodin A1, also inhibits tachyzoites and the liver stage of , with no cross-resistance to the known antimalarial targets PfACS, PfCARL, PfPI4K, or DHODH. In , inhibition occurs prior to multinucleation and induces parasite death following 12 h of compound exposure. This moderately fast activity has impeded resistance line generation, with xanthoquinodin A1 demonstrating an irresistible phenotype in both and .
Topics: Plasmodium falciparum; Antimalarials; Toxoplasma; Drug Resistance; Plasmodium berghei; Animals; Anthraquinones; Humans
PubMed: 38810215
DOI: 10.1021/acsinfecdis.4c00232 -
Parasites, Hosts and Diseases Aug 2023Despite the recent progress in public health measures, malaria remains a troublesome disease that needs to be eradicated. It is essential to develop new antimalarial...
Despite the recent progress in public health measures, malaria remains a troublesome disease that needs to be eradicated. It is essential to develop new antimalarial medications that are reliable and secure. This report evaluated the pharmacokinetics and antimalarial activity of 1,2,6,7-tetraoxaspiro[7.11]nonadecane (N-89) using the rodent malaria parasite Plasmodium berghei in vivo. After a single oral dose (75 mg /kg) of N-89, its pharmacokinetic parameters were measured, and t1/2 was 0.97 h, Tmax was 0.75 h, and bioavailability was 7.01%. A plasma concentration of 8.1 ng/ml of N-89 was maintained for 8 h but could not be detected at 10 h. The dose inhibiting 50% of parasite growth (ED50) and ED90 values of oral N-89 obtained following a 4-day suppressive test were 20 and 40 mg/kg, respectively. Based on the plasma concentration of N-89, we evaluated the antimalarial activity and cure effects of oral N-89 at a dose of 75 mg/kg 3 times daily for 3 consecutive days in mice harboring more than 0.5% parasitemia. In all the N-89- treated groups, the parasites were eliminated on day 5 post-treatment, and all mice recovered without a parasite recurrence for 30 days. Additionally, administering oral N-89 at a low dose of 50 mg/kg was sufficient to cure mice from day 6 without parasite recurrence. This work was the first to investigate the pharmacokinetic characteristics and antimalarial activity of N-89 as an oral drug. In the future, the following steps should be focused on developing N-89 for malaria treatments; its administration schedule and metabolic pathways should be investigated.
Topics: Animals; Mice; Antimalarials; Biological Availability; Folic Acid Antagonists; Oral Medicine; Parasitemia
PubMed: 37648233
DOI: 10.3347/PHD.23044 -
Molecular Microbiology May 2024Plasmodium is an obligate intracellular parasite that requires intense lipid synthesis for membrane biogenesis and survival. One of the principal membrane components is...
Plasmodium is an obligate intracellular parasite that requires intense lipid synthesis for membrane biogenesis and survival. One of the principal membrane components is oleic acid, which is needed to maintain the membrane's biophysical properties and fluidity. The malaria parasite can modify fatty acids, and stearoyl-CoA Δ9-desaturase (Scd) is an enzyme that catalyzes the synthesis of oleic acid by desaturation of stearic acid. Scd is dispensable in P. falciparum blood stages; however, its role in mosquito and liver stages remains unknown. We show that P. berghei Scd localizes to the ER in the blood and liver stages. Disruption of Scd in the rodent malaria parasite P. berghei did not affect parasite blood stage propagation, mosquito stage development, or early liver-stage development. However, when Scd KO sporozoites were inoculated intravenously or by mosquito bite into mice, they failed to initiate blood-stage infection. Immunofluorescence analysis revealed that organelle biogenesis was impaired and merozoite formation was abolished, which initiates blood-stage infections. Genetic complementation of the KO parasites restored merozoite formation to a level similar to that of WT parasites. Mice immunized with Scd KO sporozoites confer long-lasting sterile protection against infectious sporozoite challenge. Thus, the Scd KO parasite is an appealing candidate for inducing protective pre-erythrocytic immunity and hence its utility as a GAP.
Topics: Plasmodium berghei; Animals; Mice; Organelle Biogenesis; Liver; Merozoites; Malaria; Stearoyl-CoA Desaturase; Sporozoites; Protozoan Proteins; Anopheles; Female; Endoplasmic Reticulum
PubMed: 38419272
DOI: 10.1111/mmi.15246 -
International Journal For Parasitology May 2024Malaria remains the most important arthropod-borne infectious disease globally. The causative agent, Plasmodium, is a unicellular eukaryote that develops inside red...
Malaria remains the most important arthropod-borne infectious disease globally. The causative agent, Plasmodium, is a unicellular eukaryote that develops inside red blood cells. Identifying new Plasmodium parasite species that infect mammalian hosts can shed light on the complex evolution and diversity of malaria parasites. Bats feature a high diversity of microorganisms including seven separate genera of malarial parasites. Three species of Plasmodium have been reported so far, for which scarce reports exist. Here we present data from an investigation of Plasmodium infections in bats in the western Guinean lowland forest in Sierra Leone. We discovered a new Plasmodium parasite in the horseshoe bat Rhinolophus landeri. Plasmodium cyclopsi infections in a member of leaf-nosed bats, Doryrhina cyclops, exhibited a high prevalence of 100%. Phylogenetic analysis of complete mitochondrial genomes and nine nuclear markers recovered a close relationship between P. cyclopsi and the new Plasmodium parasite with the rodent species Plasmodium berghei, a widely used in vivo model to study malaria in humans. The data suggests that the "rodent/bat" Plasmodium (Vinckeia) clade represents a diverse group of malarial parasites that would likely expand with a systematic sampling of small mammals in tropical Africa. Identifying the bat Plasmodium repertoire is central to our understanding of the evolution of Plasmodium parasites in mammals.
PubMed: 38762159
DOI: 10.1016/j.ijpara.2024.05.002 -
Malaria Journal Apr 2024The use of fluorescent proteins (FPs) in Plasmodium parasites has been key to understand the biology of this obligate intracellular protozoon. FPs like the green... (Review)
Review
The use of fluorescent proteins (FPs) in Plasmodium parasites has been key to understand the biology of this obligate intracellular protozoon. FPs like the green fluorescent protein (GFP) enabled to explore protein localization, promoter activity as well as dynamic processes like protein export and endocytosis. Furthermore, FP biosensors have provided detailed information on physiological parameters at the subcellular level, and fluorescent reporter lines greatly extended the malariology toolbox. Still, in order to achieve optimal results, it is crucial to know exactly the properties of the FP of choice and the genetic scenario in which it will be used. This review highlights advantages and disadvantages of available landing sites and promoters that have been successfully applied for the ectopic expression of FPs in Plasmodium berghei and Plasmodium falciparum. Furthermore, the properties of newly developed FPs beyond DsRed and EGFP, in the visualization of cells and cellular structures as well as in the sensing of small molecules are discussed.
Topics: Green Fluorescent Proteins; Plasmodium berghei; Promoter Regions, Genetic; Plasmodium falciparum; Protein Transport
PubMed: 38643106
DOI: 10.1186/s12936-024-04936-9 -
Journal of Experimental Pharmacology 2024Malaria is causing high mortality and morbidity due to resistance to currently available anti-malarial drugs and mosquito's resistance to insecticides. Thus, there is a...
BACKGROUND
Malaria is causing high mortality and morbidity due to resistance to currently available anti-malarial drugs and mosquito's resistance to insecticides. Thus, there is a critical need to search for novel anti-malarial drugs from natural sources. Therefore, this study investigated in vivo antimalarial activities of two Ethiopian medicinal plants, Pax and Thonn, in infected Swiss albino mice.
METHODS
Soxhlet extraction method using 80% methanol as a solvent was used to prepare crude extracts of the two plants. Acute oral toxicity and 4-day suppressive in vivo antimalarial activity tests were performed on healthy female mice and infected male mice, respectively. Antimalarial activity of the crude extracts at doses of 100, 200, and 400 mg/kg and the standard drug, chloroquine were used to assesse in infected Swiss albino mice. Parasitemia level, packed cell volume, body weight, and rectal temperature of the mice were determined before infection (day 0) and after treatment (day 4). Survival time was determined by recording the date on which the mice died, considering the date of infection as day 0. The recorded data were analyzed using ANOVA and SPSS version 24.
RESULTS
The result of the acute toxicity study revealed that the crude extracts were non-toxic at doses up to 2 g/kg. The extract of suppressed parasitemia level by 66.28, 63.44 and 63.14% at 400, 200, and 100mg/kg, levels while extract suppressed parasitemia level by 45.29% at a dose of 400mg/kg. The remaining two dose levels of extract suppressed parasitemia level by < 30%.
CONCLUSION
and showed anti-plasmodial activities. exhibited a more pronounced anti-plasmodial effect than . The activities of both plants observed in this study support their traditional use as antimalarial drugs. Further studies on these plants using solvent fractions are required to identify their active ingredients.
PubMed: 38826847
DOI: 10.2147/JEP.S457659 -
Malaria Journal Nov 2023Acquired functional inhibitory antibodies are one of several humoral immune mechanisms used to neutralize foreign pathogens. In vitro bioassays are useful tools for...
BACKGROUND
Acquired functional inhibitory antibodies are one of several humoral immune mechanisms used to neutralize foreign pathogens. In vitro bioassays are useful tools for quantifying antibody-mediated inhibition and evaluating anti-parasite immune antibodies. However, a gap remains in understanding of how antibody-mediated inhibition in vitro translates to inhibition in vivo. In this study, two well-characterized transgenic Plasmodium berghei parasite lines, PbmCh-luc and Pb-PfCSP(r), and murine monoclonal antibodies (mAbs) specific to P. berghei and Plasmodium falciparum circumsporozoite protein (CSP), 3D11 and 2A10, respectively, were used to evaluate antibody-mediated inhibition of parasite development in both in vitro and in vivo functional assays.
METHODS
IC values of mAbs were determined using an established inhibition of liver-stage development assay (ILSDA). For the in vivo inhibition assay, mice were passively immunized by transfer of the mAbs and subsequently challenged with 5.0 × 10 sporozoites via tail vein injection. The infection burden in both assays was quantified by luminescence and qRT-PCR of P. berghei 18S rRNA normalized to host GAPDH.
RESULTS
The IC values quantified by relative luminescence of mAbs 3D11 and 2A10 were 0.396 µg/ml and 0.093 µg/ml, respectively, against transgenic lines in vitro. Using the highest (> 90%) inhibitory antibody concentrations in a passive transfer, an IC of 233.8 µg/ml and 181.5 µg/ml for mAbs 3D11 and 2A10, respectively, was observed in vivo. At 25 µg (250 µg/ml), the 2A10 antibody significantly inhibited liver burden in mice compared to control. Additionally, qRT-PCR of P. berghei 18S rRNA served as a secondary validation of liver burden quantification.
CONCLUSIONS
Results from both experimental models, ILSDA and in vivo challenge, demonstrated that increased concentrations of the homologous anti-CSP repeat mAbs increased parasite inhibition. However, differences in antibody IC values between parasite lines did not allow a direct correlation between the inhibition of sporozoite invasion in vitro by ILSDA and the inhibition of mouse liver stage burden. Further studies are needed to establish the conditions for confident predictions for the in vitro ILSDA to be a predictor of in vivo outcomes using this model system.
Topics: Mice; Animals; Antibodies, Monoclonal; Plasmodium berghei; Plasmodium falciparum; RNA, Ribosomal, 18S; Protozoan Proteins; Animals, Genetically Modified; Antibodies, Protozoan; Malaria Vaccines
PubMed: 37936181
DOI: 10.1186/s12936-023-04765-2