Background Ensuring rapid, accurate diagnosis and effective treatment is critical to sustaining gains and achieving the ultimate goal of malaria elimination. Invasive blood-based diagnosis is hindered by low compliance and socio-cultural barriers, highlighting the need for non-invasive alternatives in malaria detection. The study evaluated the potential of urine and saliva as non-invasive alternatives for malaria diagnosis. Methods Individuals who provided informed consent, visiting the sample collection sites were enrolled. Demographic and clinical data were recorded in individual case report forms. Blood, urine, and saliva were collected for malaria detection using CareStart RDT. Blood samples were also examined by light microscopy to determine parasite load and some used for the preparation of dried blood spots. DNA was extracted using the chelex-100 method and subjected to Plasmodium speciation by nested PCR. Results The diagnostic sensitivities of saliva and urine RDT using PCR as reference were respectively 61.0% and 57.9% while the specificities were both 96.0% with Plasmodium falciparum being the most prevalent parasite species in the study site. Conclusions The sensitivities of Carestart RDT using urine and saliva were below the 90% threshold required by WHO for confident diagnosis of malaria. Urine and saliva are therefore unsuitable replacements for blood using blood-based Carestart RDT in malaria diagnosis.
Glucose-6-phosphate dehydrogenase deficiency is prevalent in populations where malaria is endemic. Due to the risk of haemolysis, it is essential to test G6PD before malaria treatment. This study aims to determine the risk of malaria and G6PD deficiency on the occurrence of haemolytic anaemia in children from 6 months to 10 years old, in Douala. A cross-sectional hospital-based study was carried out between February and April 2024. Blood was collected from 143 children at Douala Laquintinie Hospital. A haematological test was done for full blood count. A Biochemical test for G6PD deficiency was done and microscopy for Plasmodium identification was carried out. Data were analysed using Statistical Package for the Social Sciences version 25.0 for data cleaning and analyse with R-studio version 2023.9. A Kruskal-Wallis test was carried out to assess the association between haematological parameters, G6PD levels and malaria. The prevalence of malaria, G6PD deficiency and anaemia among participants were 18.18
Schistosomiasis, a parasitic disease transmitted by freshwater snails, affects over 251.4 million people globally, with sub-Saharan Africa bearing 95% of the disease burden. This study evaluates the phytochemical composition, characterizes the bioactive secondary metabolites, antioxidant, anti-inflammatory, and the cercaricidal properties, as well as the biosafety of the methanolic and hexane extracts of Chromolaena odorata. Phytochemical screening of C. odorata extracts identified tannins, flavonoids, and saponins in the methanolic extract and steroids and alkaloids in the hexane extract. LC-MS and HPLC-UVESI-TOF-MS analyses confirmed the presence of polyphenols (flavonoids) and aromatic dicarboxylic acid compounds. Antioxidant analysis revealed strong free radical scavenging potential of the plant extracts. Both extracts demonstrated potent cercaricidal activity against Schistosoma mansoni, with LC50 values as low as 0.2012 and 0.2410 μg/mL, respectively. The anti-inflammatory effects were determined via inhibition of heat-induced albumin denaturation, with plant extracts able to inhibit protein denaturation, particularly the methanolic extract that shows a percentage of inhibition of 73.56% at the highest concentration tested. Cytotoxicity assays on LLCMK2 cells showed low toxicity of the extracts. These findings suggest that crude C. odorata extracts possess antischistosomal, antioxidant, and anti-inflammatory properties, supporting their potential integration into primary healthcare strategies for schistosomiasis control.
Despite efforts to curb the debilitating effects of malaria, incidence is still on the rise. Rapid diagnosis and effective treatment remain key strategies for reducing morbidity and mortality. The limitations of common antigens used for rapid diagnosis necessitate the search for alternatives. Studies carried out by Azcárate and colleagues have identified immunogenic proteins expressed in both clinical and subclinical malaria, which can therefore serve as diagnostic targets. This study is aimed at designing and validating a multi-epitope antigen to detect Plasmodium falciparum. The amino acid sequences of five proteins previously reported to be immunogenic in infected malaria cases were retrieved from the Uniprot database, and linear B-cell epitopes were predicted and joined using GSGSG linkers to produce a chimeric protein (PfMEDA1). The physicochemical properties of the protein, as well as the secondary and tertiary structures, were predicted. The gene sequence of the protein after reverse transcription and codon optimization was synthesized, cloned into a pET30a(+) vector, expressed, and purified from E coli. Antibody reactivity against PfMEDA1 was assessed using an indirect ELISA with human serum samples from infected (n = 223) and non-infected (n = 81) malaria cases collected from hospitals in Fako Division of the South West Region of Cameroon. The in silico-designed protein was predicted to be soluble, stable in varying climatic conditions, and immunogenic. There was a significant difference (P < 0.0001) observed between the mean OD in infected and non-infected samples, with a diagnostic sensitivity of 89.69
Background: Despite efforts invested by both national and international organizations to curb the debilitating effects of malaria, incidences are still on the rise. Rapid diagnosis, prompt and effective treatments are key strategies aimed at reducing morbidity and mortality associated with this ancient scourge. Demerits of common antigens used in rapid diagnosis necessitate the search for alternative antigens with improved diagnostic characteristics. This study is therefore aimed at designing and validating a specific and sensitive multi-epitope antigen to detect P. falciparum malaria Methods The amino acid sequences of five proteins previously reported to be immunogenic in infected malaria cases were retrieved from the Uniprot database and Linear B cell epitopes predicted and joined using GSGSG linkers to produce a chimeric protein ( Pf MEDA1). The physicochemical properties of the protein as well as the secondary and tertiary structures were predicted. The gene sequence of the protein after reverse transcription and codon optimization was synthesized, cloned in a pET30a vector, expressed and purified from E coli. Antibody reactivity against Pf MEDA1 was checked using an indirect ELISA with human serum samples from infected and non-infected malaria cases. Results The in silico-designed protein was predicted to be soluble, stable in varying climatic conditions, and immunogenic. There was a significant difference (P > 0.0001) observed between the mean OD in infected and non-infected samples, with a diagnostic sensitivity of 89.69% and a Cohen kappa value of 0.61 implying substantial agreement with the PCR serving as the reference method. Conclusion Based on the antibody capture ELISA test, Pf MEDA 1 exhibited the potential to be used in the development of a diagnostic tool for the diagnosis of P. falciparum in malaria endemic settings.
Objectives:Malaria burden is primarily owing to resistance of parasites and vectors to frontline drugs and insecticides, respectively. Increasing awareness of factors contributing to parasite resistance to antimalarials within communities is crucial. This study assessed how community knowledge, attitudes, and practices (KAPs) influence factors contributing to antimalarial resistance across four malaria ecological zones in Cameroon.Methods:To accomplish this, structured questionnaires were administered to 980 volunteers from four geographical locations in English or French (the official languages of Cameroon). The data were organized and tested for normality. Spearman rank correlation was used to examine the connection between KAP and malaria.Results:The mean KAP scores were 5.69 ± 1.47, 5.91 ± 1.25, and 5.66 ± 1.84, respectively, on a nine-point scale. Antimalarials commonly used were artemisinin-based combination therapies (37.96%), chloroquine (4.29%), quinine (22.24%), paracetamol (12.96%), and native drugs (19.80%). Up to 49.49% of the participants practiced self-medication, whereas 76.43% bought medications from licensed pharmacies, 10.61% bought from roadside vendors, and 23.57% relied on traditional/herbal medicines. We observed significant and medium positive linear correlations at P <0.01 between knowledge-attitude (r = 0.528), knowledge-practice (r = 0.400), and attitude-practice (r = 0.496).Conclusions:Despite the general fair level of awareness of proper management and use of antimalarial drugs in the communities, the high level of self-medication and gross neglect of certain risk factors that may promote the emergence and spread of drug-resistant parasites is concerning.
BackgroundNutritional deficiencies and its consequences such as anaemia are frequent among pregnant women residing in under resource settings. Hence, this study sought to investigate specific dietary micronutrient inadequacy and its effect on maternal haemoglobin levels.MethodsThis institution based cross-sectional survey enrolled 1,014 consenting pregnant women consecutively. Data on socio-demographic, economic and antenatal characteristics were recorded using a structured questionnaire. Minimum dietary diversity for women (MDD-W) was assessed using the 24-h recall method and haemoglobin (Hb) concentration (g/dL) determined using a portable Hb metre. Significant levels between associations was set at p < 0.05.ResultsAmong those enrolled, 40.9% were anaemic while 89.6% had inadequate dietary nutrient intake. In addition, uptake of blood supplements, haem iron, plant and animal-based foods rich in vitamin A were 71.5, 86.2, 35.5 and 12.6%, respectively. Moreover, anaemia prevalence was significantly (p < 0.05) lower in women who took iron-folic acid along with food groups rich in haem iron (38.5%) or both plant and animal vitamin A (29.0%). Besides, mean maternal Hb levels was significantly (p < 0.001) higher in women who consumed haem iron (11.08 ± 1.35) and vitamin A food groups (11.34 ± 1.30) when compared with their counterparts who did not consume haem iron (10.54 ± 1.19) and vitamin A food groups (10.74 ± 1.31).ConclusionDietary uptake of foods rich in haem-iron and vitamin A significantly improves Hb levels in Cameroonian pregnant women. Our findings underscore the importance of improving maternal nutritional awareness and counselling during antenatal period to reduce the anaemia burden.
It is known that the pathogenicity of Plasmodium induces the breakdown of haemoglobin, which leads to the induction of oxidative stress. This study aimed to identify the possible effects of oxidative stress and antioxidant defence systems in symptomatic and asymptomatic Plasmodium falciparum malaria infection in children (1 - 15 years old) in the Mount Cameroon vicinity. This cross-sectional study involved blood samples collected from 473 children and examined for malaria parasitaemia. Full blood counts were performed using an automated haemoanalyser. Serum oxidative stress status (malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and vitamin C (Vit C)) were each determined by colorimetric enzymatic assays. The prevalence of malaria parasite infection was 32.1% among the participants. Out of that, 62.5% of patients with parasitaemia were symptomatic. Anaemia prevalence increased significantly with parasite density. MDA levels were significantly higher in patients with malaria symptoms than in those without symptoms. A significant and positive correlation was detected between MDA (r = 0.831, P < 0.05), NO (r = 0.779, P < 0.05), and malaria parasite density while, a significant and negative relationship occurred between parasite density and GSH (r = ?0.763, P < 0.05) and Vit C (r = ?0.826, P < 0.05) levels, SOD (r = ?0.621, P < 0.05) and CAT (r = ?0.817, P < 0.05) activities. The SOD activity and GSH level significantly decreased (P < 0.05) with an increase in the MDA levels. These findings showed that MDA and nitric oxide levels increased both in malaria participants with or without symptoms. A similar decrease in the antioxidant defence system was observed in both symptomatic and asymptomatic patients. Therefore, there is a need to develop public health policies that encourage routine diagnosis and treatment of malaria in seemingly healthy people (asymptomatic cases), and this will play an essential role in controlling malaria in tropical countries.
Drug-resistant malaria parasites pose a threat to global malaria control efforts, and it is important to know the extent of these drug-resistant mutations in each region to determine appropriate control measures. Chloroquine (CQ) was widely used in Cameroon for decades, but its declining clinical efficacy due to resistance prompted health authorities in 2004 to resort to artemisinin-based combination therapy (ACT) as the first-line treatment for uncomplicated malaria. Despite numerous efforts to control malaria, it persists, and the emergence and spread of resistance to ACTs make the development of new drugs or the possible reintroduction of discontinued drugs increasingly urgent. Malaria-positive blood samples were collected from 798 patients on Whatman filter paper to determine the status of resistance to CQ. DNA was extracted by boiling in Chelex and analysis of Plasmodium species. Four hundred P. falciparum monoinfected samples, 100 per study area, were amplified by nested PCR, and allele-specific restriction analysis of Pfmdr1 gene molecular markers was performed. Fragments were analyzed using a 3% ethidium bromide-stained agarose gel. P. falciparum was the most abundant Plasmodium species, accounting for 87.21% of P. falciparum monoinfections only. No infection with P. vivax was detected. The majority of samples contained the wild type for all 3 SNPs evaluated on the Pfmdr1 gene with N86, Y184, and D1246 accounting for 45.50%, 40.00%, and 70.00%, respectively. The most abundant haplotype observed was the Y184D1246 double wild type at 43.70%. The results suggest that P. falciparum is the major infecting species and that P. falciparum species with the susceptible genotype are gradually recapturing the parasite population.
Ethnopharmacological relevance: Cymbopogon citratus (DC.) Stapf (Poaceae) is a medicinal plant known for its antimalarial, antipyretic and antifatigue activities in Cameroonian folk medicine. Aim of the study: The aim of this work was to evaluate the prophylactic antimalarial effects of the decoction prepared from the leaves of Cymbopogon citratus on Plasmodium berghei ANKA infection in mice and investigate its action on haematological and serum biochemical status. Materials and methods: Swiss mice were treated with Cymbopogon citratus leaf decoction (25, 50, 100 and 200 mg/kg) and later inoculated with Plasmodium berghei ANKA. The prophylactic antimalarial activity of the decoction was evaluated by determining the parasitaemia, percentage chemosuppression, body weight, body temperature, food and water intake in pretreated parasitised mice. The possible ameliorative effects of the decoction on malaria associated haematological and serum biochemical changes were also assessed. Results: The decoction exhibited a prophylactic activity of 85.32% and its chemotherapeutic effects ranged from 56.88 – 85.32% with maximum effect observed at the highest experimental dose. It significantly inhibited parasitaemia (P < 0.001) compared to the negative control group. Interestingly, treatment of parasitised mice with the decoction significantly restored the malaria modified haematological and biochemical status compared with distilled water-treated parasitised mice. Conclusion: The results of this prophylactic assay indicated that Cymbopogon citratus decoction has antimalarial effects and normalised haematological and serum biochemical aberrations generated by malaria. Hence, Cymbopogon citratus represents a promising source of new antimalarial agents.
Ethnopharmacological relevance: Milk production, processing and consumption are integral part of traditional practices in Fulani tribe of Cameroon. It has been observed that Fulani are resistant to malaria. Dairy products traditionally processed by Fulani are intensively used in the ritual treatment of malarial, inflammations and behavioural disorders. Many studies have demonstrated that fermented milk is a rich source of probiotic bacteria. However, the antimalarial activity of probiotics isolated from this natural source has not been experimentally tested. Aim of the study: Hence, this study was therefore aimed at evaluating the antimalarial activity of a probiotic bacterium Lactobacillus sakei isolated from traditionally fermented milk in mice infected with chloroquine sensitive Plasmodium berghei ANKA. Materials and methods: The probiotic bacterium was isolated from the Cameroonian Mborro Fulani's traditionally fermented milk and identified using the 16S r RNA gene sequencing. The schizontocidal activity of Lactobacillus sakei on established malaria infection was evaluated. Eighty-four healthy young adult Balb/c mice infected with Plasmodium berghei parasite were randomly divided into two sets of seven group of six mice each, and were given three different doses of Lactobacillus sakei, chloroquine and sulfadoxine/pyrimethamine for seven and fourteen days respectively. The level of parasitaemia, body temperature, survival time and haematological parameters were evaluated. Results: The parasite growth inhibition was observed to increase with increasing dose of probiotic bacterium with maximum suppression being 100 % at dose 3 on day 20. Also, the probiotic bacterium significantly prevented body weight loss and was associated with body temperature reduction and prevented (p<0.05) a decrease in haematological parameters compared to that untreated malaria infected mice. Conclusion: The results obtained suggest that Lactobacillus sakei is a probiotic bacterium with antimalarial activity in mice infected with chloroquine sensitive Plasmodium berghei.
The small leucine-rich proteoglycan, decorin, has incrementally been shown to be a powerful inhibitor of growth in a wide variety of tumour cells, an effect specifically mediated by the interaction of decorin core protein with the epidermal growth factor receptor (EGFR) and other ErbB family proteins. Nowadays, this matrikine has become the main focus of various cancer studies. Decorin is an important component of the cellular microenvironment or extracellular matrix (ECM). Its interactions with matrix and cell membrane components have been implicated in many physiological and pathophysiological processes including matrix organisation, signal transduction, wound healing, cell migration, inhibition of metastasis, and angiogenesis. This review summarises recent findings on decorin's interactions and behaviour related to cancer. Highlighted are key functions of decorin such as interaction with cell surface receptors, as well as with ECM components, and the therapeutic potential of this multifunctional molecule.
Human skin fibroblasts efficiently internalize the matrikine decorin by receptor-mediated endocytosis, however, very little is known about its intracellular trafficking routes up to lysosomal degradation. In an in vitro system measuring uptake and degradation of [35S]sulfate-labeled decorin, endocytosis was blocked by 46% when clathrin assembly/disassembly was inhibited using chlorpromazine. Pharmacological inhibition of EGF receptor signaling caused 34% reduction of decorin uptake, whereas inhibition of the IGF receptor had no effect. Using confocal immunofluorescence microscopy, we determined that only about 5–10% of internalized decorin colocalized with the EGFR. Thus, uptake depends on EGFR signaling rather than trafficking along the same pathway. Decorin passes through early endosomes towards trafficking to lysosomes, since more than 50% of decorin colocalized with EEA1. Moreover, inhibition of endosomal fusion by wortmannin caused a profound inhibition of decorin endocytosis. Overexpression of the clathrin-binding Hrs protein, which has previously been shown to inibit EGFR degradation blocked the degradation of decorin. Cholesterol depletion by filipin inhibited uptake of decorin by 34%, however, nearly no intracellular colocalization was found between decorin and caveolin-1. The combined use of filipin and chlorpromazine had an additive inhibitory effect on decorin endocytosis. Moreover, chlorpromazine diverted decorin from the chlorpromazine-sensitive pathway to an alternative uptake route. The CD44/hyaluronan pathway was excluded as an endocytic route for decorin. Our observations indicate that decorin is taken up by more than one endocytic pathway. Of note, lipid-raft-dependent EGFR signaling modulates decorin uptake, suggesting the presence of a potential feedback regulation mechanism for desensitization of signaling events mediated by decorin.
The small leucine-rich proteoglycan (SLRP) decorin is efficiently internalized by a variety of cultured cells. A 51-kDa protein has previously been described as a receptor mediating endocytosis of decorin and of the structurally related SLRP biglycan. Recent findings suggest that endocytosis of SLRPs may also be mediated by additional receptors. The class-A scavenger receptor, the endocytic mannose receptor, the epidermal growth factor receptor, and insulin-like growth factor-I receptor have emerged as candidates. We used a combined approach of immunoprecipitation and photoactivated cross-linking to identify endocytosis receptors for decorin in human skin fibroblasts. Decorin was purified by HPLC-DEAE-ion exchange chromatography from the secretions of human skin fibroblasts under nondenaturing conditions. Confocal immunofluorescence microscopy revealed that both biotinylated decorin and decorin conjugated to the heterobifunctional cross-linker sulfosuccinimidyl 2-(p-azidosalicylamido)ethyl-1-3'-dithiopropionate (SASD) were endocytosed with equal efficiency. SASD-conjugated decorin was added to [35S]-methionine-labeled fibroblasts and cross-linked intracellularly to receptor molecules by photoactivation on endocytic uptake. Cross-linked decorin-receptor complexes were purified from the extracts of trypsin-treated fibroblasts by anion exchange chromatography and immunoprecipitation with a decorin-specific antiserum. Analysis by 2D electrophoresis and autoradiography revealed that decorin was specifically cross-linked to a protein of 110 kDa, which exhibited an isoelectric point of 5.5. In a second approach, unlabeled fibroblasts were subjected to decorin endocytosis and photoactivated cross-linking followed by Western blotting of DEAE-purified cell extracts. A shift of biotinylated decorin immunoreactivity from 165 kDa (decorin-receptor complex) to 54 kDa (SASD-conjugated biotinylated decorin) was noted on reductive cleavage of the cross-linker, representing a difference in molecular weight of approximately 110 kDa. The identification of a 110-kDa protein as a novel endocytosis receptor for decorin provides further support for the emerging concept of a redundancy of receptor molecules in the endocytosis of SLRP.
Bisdermican (PG760) is a large, heterodimeric, dermatan sulfate proteoglycan found in selected basement membranes, smooth muscle cell layers, and different extracellular matrices. Age-dependent and developmentally regulated alterations in glycosaminoglycan structure and quantity have been shown to be functionally relevant for a number of physiological and pathological processes. Bisdermican was purified from human skin fibroblast cultures of different age and confluency. Following β-elimination, glycosaminoglycan chains were analyzed by Sephacryl-S-300 chromatography. Glycosaminoglycan chains of Bisdermican from infantile fibroblasts had a molecular weight of 19 kDa, whereas the glycosaminoglycan chain of the large Bisdermican subunit purified from confluent fetal fibroblast secretions was slightly larger (Mr = 24 kDa). Bisdermican derived from subconfluent cultures of fetal fibroblasts displayed the largest glycosaminoglycan chains with a molecular weight of 31.5 kDa for the large subunit, and a molecular weight of 22 kDa for the small subunit. Thus, Bisdermican displays a molecular polymorphism that is related to its chronological age and proliferative state.