Regulatory T cells modulate monocyte functions in immunocompetent antiretroviral therapy naive HIV-1 infected people.

We previously demonstrated that the overall number of regulatory T (Treg) cells decrease proportionately with helper CD4+ T cells and their frequencies increase in antiretroviral therapy (ART)-naive human immunodeficiency virus type-1 (HIV-1) infected individuals. The question now is whether the discrepancies in Treg cell numbers and frequencies are synonymous to an impairment of their functions. To address this, we purified Treg cells and assessed their ability to modulate autologous monocytes functions. We observed that Treg cells were able to down modulate autologous monocytes activation as well as interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) production during stimulation with polyinosinic-polycytidylic acid stabilized with poly-L-lysine and carboxymethylcellulose (poly-ICLC). This activity of Treg cells has been shown to be influenced by immunocompetence including but not limited to helper CD4+ T cell counts, in individuals with HIV-1 infection. Compared to immunosuppressed participants (CD4 < 500 cells/µL), immunocompetent participants (CD4 ≥ 500 cells/µL) showed significantly higher levels of transforming growth factor beta (TGF-ß) and IL-10 (p < 0.001 and p < 0.05, respectively), key cytokines used by Treg cells to exert their immunosuppressive functions. Our findings suggest the contribution of both TGF-ß and IL-10 in the suppressive activity of Treg cells.

Metallo-ß-lactamase and AmpC genes in Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa isolates from abattoir and poultry origin in Nigeria.

BACKGROUND: Gram-negative bacteria (GNB) including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae represent the most relevant reservoir of resistance genes such as metallo-ß-lactamase (MBL) and AmpC genes that give them the undue advantage to resist antimicrobial onslaught. This study aimed to investigate the occurrence of MBL (blaIMP-1, blaIMP-2, blaVIM-1, blaVIM-2) and AmpC (blaFOX, blaDHA, blaCMY, blaACC) resistance genes in aforementioned GNB collected from abattoir and poultry sources in Nigeria. RESULTS: In total, 370 isolates were collected from abattoir tables (n = 130), anal region of cows (n = 120), and the cloacae of poultry birds (n = 120). The test isolates showed high rate of resistance to cephalosporins and carbapenems. The MBLs were phenotypically detected in 22 E. coli, 22 P. aeruginosa, and 18 K. pneumoniae isolates using combined disc test (CDT). However, only 11 E. coli, 24 P. aeruginosa, and 18 Klebsiella pneumoniae isolates were phenotypically confirmed to be AmpC producers using cefoxitin-cloxacillin double disk synergy test (CC-DDST). MBL encoding genes (particularly the blaIMP-1 genes and blaIMP-2 genes) were detected by polymerase chain reaction (PCR) in 12 (54.6%) E. coli, 15 (83.3%) K. pneumoniae, and 16 (72.7%) P. aeruginosa isolates. AmpC genes (particularly the blaCMY genes and blaFOX genes) were found in a total of 5 (29.4%) E. coli isolates, 5 (27.8%) isolates of K. pneumoniae, and 10 (41.7%) isolates of P. aeruginosa. CONCLUSIONS: Our study showed the circulation of MBL and AmpC genes in GNB from abattoir and poultry origin in Nigeria. Adoption of regular control policies is necessary to reduce the spread of these species as soon as possible, especially in poultry and slaughterhouses.

Absence of Plasmodium falciparum artemisinin resistance gene mutations eleven years after the adoption of artemisinin-based combination therapy in Nigeria.

BACKGROUND: The occurrence of artemisinin resistance (ART)-associated polymorphism of Plasmodium falciparum K13-propeller (pfk13) gene before and after the introduction of artemisinin-based combination therapy (ACT) in two regions of Nigeria was investigated in this study. Regular surveillance is necessary to make a definite conclusion on the emergence and pattern of possible resistance to ART. METHODS: This cross-sectional study was carried out in the Southwestern and Southeastern geopolitical zones of Nigeria. A total of 150, 217, and 475 participants were enrolled for the study in the Southwest (2004_Group A), Southwest (2015_Group B), and southeast (2015_Group C), respectively. Blood samples were collected from the study participants for DNA extraction and a nested PCR for P. falciparum identification. Samples that were positive for P. falciparum were genotyped for the pfk13 gene using the Sanger sequencing method. The single nucleotide polymorphisms were analysed using the Bioedit software. RESULTS: A total of 116, 125, and 83 samples were positive for P. falciparum, respectively for the samples collected from the Southwest (2004 and 2015) and southeast (2015). Parasite DNA samples collected from febrile children in 2004 (Group A; n = 71) and 2015 (Group B; n = 73) in Osogbo Western Nigeria and 2015_Group C (n = 36) in southeast Nigeria were sequenced successfully. This study did not observe mutations associated with the in vitro resistance in southeast Asia, such as Y493H, R539T, I543T, and C580Y. Two new polymorphisms V520A and V581I were observed in two samples collected in Osogbo, Southwest Nigeria. These two mutations occurred in the year 2004 (Group A) before the introduction of ACT. Six mutations were identified in 17% of the samples collected in southeast Nigeria. One of these mutations (D547G) was non-synonymous, while the remaining (V510V, R515R, Q613Q, E688E, and N458N) were synonymous. Also, one (2%) heterozygote allele was identified at codon 458 in the 2015 (Group C) samples. CONCLUSIONS: None of the mutations observed in this study were previously validated to be associated with ART resistance. These results, therefore, suggest that artemisinin is likely to remain highly effective in treating malaria in the study areas that are malarious zone.

Analysis of Plasmodium falciparum Pfcrt and Pfmdr1 genes in parasite isolates from asymptomatic individuals in Southeast Nigeria 11 years after withdrawal of chloroquine.

BACKGROUND: A reversal of chloroquine (CQ) resistance following a period of withdrawal has raised the possibility of its re-introduction. This study evaluated the current prevalence of Pfcrt and Pfmdr1 alleles in Plasmodium falciparum isolates, 11 years after CQ withdrawal in Southeast Nigeria. METHODS: Filter-paper blood samples were collected from 725 non-febrile individuals, comprising 250 children (≤ 12 years), 250 pregnant women and 225 other adults, between October 2014 and February 2015 in Nnewi town, Southeast Nigeria. Nested PCR followed by direct sequencing was employed for the genotyping of Pfcrt and Pfmdr1 genes. RESULTS: A total of 103 parasites-positive samples were recovered, comprising of 48 (19.20%) among children, 20 (20.00%) among pregnant women and 35 (15.50%) among other adults cohort. The frequency of the mutant genotype of Pfcrt 76T, 75E and 74I was 94.50% each. Parasite isolates from children had a frequency of 100% for mutant alleles in all Pfcrt codons while isolates from pregnant women and other adults had a frequency of 91% each in all codons. Haplotype distribution of pfcrt gene were 5.45, 0.00 and 76.37% for CVMNK, SVMNT and CVIET, respectively. For Pfmdr1 gene, the frequency of 86Y, 184F and 1246Y mutant alleles were 8.54, 29.27 and 3.66%, respectively. Amongst the Pfmdr1 haplotypes analysed, NFD had the highest frequency of 24.4%, followed by YFD at 6.10%. NYF and NYY occurred the least (1.20%). CONCLUSION: The high level of Pfcrt mutations is suggestive of a sustained CQ pressure on P. falciparum isolates in the study area, despite the change of first line treatment from CQ to artemisinin combination therapy for 11 years. A new strategy to ensure the complete withdrawal of CQ from the country is recommended.

Antibacterial, anti-inflammatory and peroxidase-mediated cyclooxygenase-1 inhibitory properties of Fusarium solani extract.

Context: Nigerian soil fungi population is unexplored. It is hypothesized that they harbour new bioactive chemicals. This hypothesis is based on the large percentage of currently approved medicines that originated from soil-inhabiting micro-organisms Objectives: To investigate the antimicrobial and anti-inflammatory properties of Fusarium solani ethyl acetate (EtOAc) extract selected based on its broad spectrum of antimicrobial potential in an overlay experiment with seven other soil fungi strains. Materials and methods: Fungus number 6 (F6), identified by molecular characterization as Fusarium solani (Mart.) Sacc (Nectriaceae) was selected for studies from eight purified soil fungi due to its superior broad-spectrum antibiotics producing potential following agar overlay experiment. F6 was fermented for 21 d and the minimum inhibitory concentration (MIC) of its EtOAc fermentation extract (dose range: 12.5-100 µg/mL) was determined using agar dilution method for Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi and anti-inflammatory properties determined using rat-paw (250-500 mg/kg) and xylene induced oedema (250-500 µg/kg) (in Swiss albino rats and mice) models, respectively. The ability of the extract to inhibit cyclooxygenase (COX) enzyme was also determined in vitro using Cayman test kit-760111. Result: The MIC of the EtOAc extract was <12.5 µg/mL for S. aureus, P. aeruginosa and Escherichia coli. It inhibited xylene induced oedema by 65% compared with 61% observed for diclofenac and was significantly (p < 0.05) better than diclofenac in rat-paw-oedema model within the first phase of inflammation. The extract inhibited COX-1 peroxidase-mediated activities with an IC50 below 5 µg/mL. Conclusions: The extract exhibited strong antibacterial and anti-inflammatory properties, warranting further investigations into therapeutic potential of this fungus. This study design can be adapted in soil fungi metabolomic investigations. We report for the first time the potent anti-inflammatory property of the ethyl acetate extract of soil strain of F. solani with a possible mechanism of action that involves the inhibition of COX enzyme.

Filaria specific antibody response profiling in plasma from anti-retroviral naïve Loa loa microfilaraemic HIV-1 infected people.

BACKGROUND: In West and Central Africa areas of endemic Loa loa infections overlap with regions of high prevalence of human immunodeficiency virus type 1 (HIV-1) infections. Because individuals in this region are exposed to filarial parasites from birth, most HIV-1 infected individuals invariably also have a history of filarial parasite infection. Since HIV-1 infection both depletes immune system and maintains it in perpetual inflammation, this can hamper Loa loa filarial parasite mediated immune modulation, leading to enhanced loaisis. METHODS: In this study we have assessed in plasma from asymptomatic anti-retroviral (ARV) naïve Loa loa microfilaraemic HIV-1 infected people the filarial antibody responses specific to a filariasis composite antigen consisting of Wbgp29-BmR1-BmM14-WbSXP. The antibody responses specific to the filariasis composite antigen was determined by enzyme linked immunosorbent assay (ELISA) in plasma from ARV naïve Loa loa microfilaraemic HIV-1 infected participants. In addition the filarial antigen specific IgG antibody subclass profiles were also determined for both HIV-1 positive and negative people. RESULTS: Both Loa loa microfilaraemic HIV-1 positive and negative individuals showed significantly higher plasma levels of IgG1 (P < 0.0001), IgG2 (P < 0.0001) and IgM (P < 0.0001) relative to amicrofilaraemic participants. A significant increase in IgE (P < 0.0001) was observed exclusively in Loa loa microfilaraemic HIV-1 infected people. In contrast there was a significant reduction in the level of IgG4 (p < 0.0001) and IgG3 (P < 0.0001) in Loa loa microfilaraemic HIV-1 infected individuals. CONCLUSIONS: Loa loa microfilaraemia in ARV naïve HIV-1 infected people through differential reduction of plasma levels of filarial antigen specific IgG3, IgG4 and a significant increase in plasma levels of filarial antigen specific IgE could diminish Loa loa mediated immune-regulation. This in effect can result to increase loaisis mediated immunopathology in antiretroviral naive HIV-1 infected people.

Quality medicines in maternal health: results of oxytocin, misoprostol, magnesium sulfate and calcium gluconate quality audits.

BACKGROUND: The high level of maternal mortality and morbidity as a result of complications due to childbirth is unacceptable. The impact of quality medicines in the management of these complications cannot be overemphasized. Most of those medicines are sensitive to environmental conditions and must be handled properly. In this study, the quality of oxytocin injection, misoprostol tablets, magnesium sulfate, and calcium gluconate injections was assessed across the six geopolitical zones of Nigeria. METHOD: Simple, stratified random sampling of health facilities in each of the political zones of Nigeria. Analysis for identification and content of active pharmaceutical ingredient was performed using high-performance liquid chromatography procedures of 159 samples of oxytocin injection and 166 samples of misoprostol tablets. Titrimetric methods were used to analyze 164 samples of magnesium sulfate and 148 samples of calcium gluconate injection. Other tests included sterility, pH measurement, and fill volume. RESULTS: Samples of these commodities were procured mainly from wholesale and retail pharmacies, where these were readily available, while the federal medical centers reported low availability. Approximately, 74.2% of oxytocin injection samples failed the assay test, with the northeast and southeast zones registering the highest failure rates. Misoprostol tablets recorded a percentage failure of 33.7%. Magnesium sulfate and Calcium gluconate injection samples recorded a failure rate of 6.8% and 2.4%, respectively. CONCLUSION: The prevalence of particularly of oxytocin and misoprostol commodities was of substandard quality. Strengthening the supply chain of these important medicines is paramount to ensuring their effectiveness in reducing maternal deaths in Nigeria.

Antimalarial treatment patterns among pregnant women attending antenatal care clinics in south east Nigeria and the future implications.

BACKGROUND: Prompt and effective treatment of malaria in pregnancy in accordance with recommended guidelines is essential to help prevent adverse events among pregnant mothers and the foetus. AIM: The aim of this study was to assess current prescribing of antimalarial medicines in pregnancy against policy guidelines in south east Nigeria to provide future guidance. METHODS: A review of prescription records of pregnant women treated for malaria over a 6-month period between August 2013 and January 2014 was carried out to assess the prescribing patterns for both the prevention and treatment of malaria in each trimester and analyzed for conformity to recommended guidelines. RESULTS: Among 859 antenatal records reviewed, the majority (83.2%) were in the second and third trimesters. Artemisinin-based combination therapies (40.9%) and sulfadoxine-pyrimethamine (37.5%) were the most prescribed antimalarial medicines for both treatment and prophylaxis (prevention), respectively, in all trimesters. Overall, 68.5% of the prescriptions conformed to guideline recommendations, with the prescriptions for non-recommended drugs occurring most often in the first trimester. In the second and three trimesters, up to 79.9% of pregnant women received appropriate medicines for both treatment and prevention of malaria, with artemether-lumefantrine the most prescribed regimen. CONCLUSION: Current practice indicates greater conformity with guidelines particularly in the second and three trimesters vs previous studies. However, there are still concerns with prescribing practices in the first trimester, especially in private health facilities. This needs addressing.

Modulation of intracellular expression of IFNγ and IL-2 in culture of splenic T lymphocytes by some flavonoid glycosides of Alchornea floribunda.

Context Alchornea floribunda Müll. Arg. (Euphorbiaceae) leaves are widely used in ethnomedicine for the management of rheumatism, arthritis and toothache. Objective In this study, flavonoid glycosides isolated from Alchornea floribunda were screened for their effect on the intracellular expression of interferon-gamma (IFNγ) and interleukin-2 (IL-2) type-1 cytokines. Materials and methods Chromatographic purification of the ethyl acetate fraction of the methanol leaf extract led to the isolation of seven flavonoid glycosides (1-7). Their structures were elucidated by 1D and 2D nuclear magnetic resonance and mass spectrometry. Splenocytes were treated with graded concentrations of the compounds (6.25-25 µg/mL) and incubated for 24 h. Thereafter, their effect on the expression of IFNγ and IL-2 by CD4(+ )and CD8(+ )T-lymphocytes was evaluated using intracellular cytokine staining and FACS analysis. Results Compounds 1-7 (6.25-25 µg/mL) caused the up-regulation of activated CD8(+ )(57.85-72.45% versus 57.85% for untreated control) and, to a lesser extent, activated CD4(+ )(3.21-7.21% versus 2.75% for the untreated control) T-lymphocytes that were both largely interferon-gamma-releasing in treated mouse T lymphocytes relative to untreated control. FACS data analysis showed that stimulation with all the compounds increased the proportion of CD8(+)/IFNγ(+ )and CD4(+)/IFNγ(+ )T lymphocytes up to two-fold when compared with the cells in untreated control wells. Intracellular IL-2 secretion by treated T cells was not detected. Conclusion This recorded T-lymphocyte-specific immune-modulatory property may contribute to explain in part the dynamics associated with the ethnomedicine of Alchornea floribunda, and may find relevance as a necessary cellular immune response precursor to infection-associated disease management.

Efficacy of Plectranthus glandulosus (Lamiaceae) and Callistemon rigidus (Myrtaceae) Leaf Extract Fractions to Callosobruchus maculatus (Coleoptera: Bruchidae).

As part of on-going efforts to use eco-friendly alternatives to chemical pesticides, methanol crude extracts of Plectranthus glandulosus and Callistemon rigidus leaves were sequentially fractionated in hexane, chloroform, ethyl acetate, and methanol to establish the most active fraction(s) against Callosobruchus maculatus in cowpea. Cowpea seeds (25 g) were treated with 0.5, 1, 2, and 4 g/kg of extract to evaluate the contact toxicity and F1 progeny production of the beetles in the laboratory. Mortality was recorded 1, 3, and 7 d postexposure. P. glandulosus hexane fraction was more toxic than the other fractions recording 100% mortality at 4 g/kg, within 7 d with LC50 of 0.39 g/kg. Hexane fraction of C. rigidus showed superior toxicity, causing 100% mortality at 4 g/kg within only 1 d of exposure with LC50 of 1.02 g/kg. All the fractions greatly reduced progeny emergence, with C. rigidus hexane fraction being the best progeny inhibitor. Fractions of P. glandulosus and C. rigidus leaves had sufficient efficacy to be a component of storage pest management package for C. maculatus.

Creams formulated with Ocimum gratissimum L. and Lantana camara L. crude extracts and fractions as mosquito repellents against Aedes aegypti L. (Diptera: Culicidae).

Mosquitoes are the most deadly vectors of parasites that cause diseases such as malaria, yellow fever, and filariasis. In view of the recent increased interest in developing plant origin insecticides as an alternative to chemical insecticides, the objective of this study was to determine the repellent activity of creams formulated with methanol crude extract (MCE), hexane fraction (HF), and ethyl acetate fractions (EAFs) of Ocimum gratissimum and Lantana camara leaves in single and combined actions against female Aedes aegypti. Evaluation was carried out in the net cages (30 by 30 by 30 cm) containing 60 blood-starved female mosquitoes each and were assayed in the laboratory condition following World Health Organization 2009 protocol. All formulations (single and mixture) were applied at 2, 4, 6, and 8 mg/cm(2) in the exposed area of human hands. Only acetone + white soft paraffin served as negative control and odomos (12% DEET) as positive control. All the formulations presented good protection against mosquito bites without any allergic reaction by the human volunteers. The repellent activity was dependent on the strength of the extracts and fractions. Among the tested formulations, the maximum protection time was observed in MCE (120 min) and EAF (150 min) of O. gratissimum; MCE:MCE (150 min) and HF:HF (120 min) mixtures of both plants. In addition, MCE:MCE and HF:HF mixtures from both plants showed possible synergistic effect. From the results, the combination of O. gratissimum and L. camara to formulate natural mosquito repellent using small amount of extracts can be encouraging to be an alternative to conventional DEET.

Immunomodulatory and immunorestorative activities of ß-D-glucan-rich extract and polysaccharide fraction of mushroom, Pleurutus tuberregium.

CONTEXT: Some edible mushrooms are reputed to possess useful medicinal properties which are related to their ability to modulate the protective responses of the immune system. OBJECTIVE: This study explored the immunomodulatory and immunorestorative properties of a hot aqueous extract (APTR) and of a ß-d-glucan-enriched polysaccharide fraction (BGP) of a local oyster mushroom Pleurutus tuberregium (Fr.) Singer (Pleurotaceae). MATERIALS AND METHODS: Immunomodulatory activities were investigated by assessing specific and none-specific immune responses in immunocompetent and immunosuppressed mice; as well as in vitro in culture of RAW264.7 macrophages stimulated with BGP. RESULTS: In a homologous prime-boost immunization schedule, oral supplementation with APTR (100, 200, or 400 mg/kg) and BGP (100 or 200 mg/kg) resulted in significantly higher titers of total IgG, IgG1, and IgG2a by as much as 2-4-folds compared with the levels in untreated control mice. The mean hemagglutination (HA) titer in immunized mice that were treated with dexamethasone (DEX; 5 mg/kg) was significantly (p < 0.05) lower than the titer in groups that did not receive dexamethasone; however, short-term alternate day administration of APTR (200 mg/kg) to mice that had been immunosuppressed with 5 mg DEX/kg produced significant increases in secondary anti-SRBC antibody compared with the mean titer of mice immunized and treated with DEX alone. In in vitro studies, stimulation of RAW264.7 macrophages with BGP caused significant increases in iNO and TNF-α expression, and phagocytic functions of the cell. CONCLUSION: Taken together, the results of these studies showed that P. tuberregium imparts immunostimulatory and immunorestorative effects that could be explained, in part, by the actions of its ß-d-glucan constituent(s) on macrophages.

Drugs use pattern for uncomplicated malaria in medicine retail outlets in Enugu urban, southeast Nigeria: implications for malaria treatment policy.

BACKGROUND: Malaria treatment policy recommends regular monitoring of drug utilization to generate information for ensuring effective use of anti-malarial drugs in Nigeria. This information is currently limited in the retail sector which constitutes a major source of malaria treatment in Nigeria, but are characterized by significant inappropriate use of drugs. This study analyzed the use pattern of anti-malarial drugs in medicine outlets to assess the current state of compliance to policy on the use of artemisinin-based combination therapy (ACT). METHODS: A prospective cross-sectional survey of randomly selected medicine outlets in Enugu urban, southeast Nigeria, was conducted between May and August 2013, to determine the types, range, prices, and use pattern of anti-malarial drugs dispensed from pharmacies and patent medicine vendors (PMVs). Data were collected and analyzed for anti-malarial drugs dispensed for self-medication to patients, treatment by retail outlets and prescription from hospitals. RESULTS: A total of 1,321 anti-malarial drugs prescriptions were analyzed. ACT accounted for 72.7%, while monotherapy was 27.3%. Affordable Medicines Facility-malaria (AMFm) drugs contributed 33.9% (326/961) of ACT. Artemether-lumefantrine (AL), 668 (50.6%) was the most used anti-malarial drug, followed by monotherapy sulphadoxine-pyrimethamine (SP), 248 (18.8%). Median cost of ACT at $2.91 ($0.65-7.42) per dose, is about three times the median cost of monotherapy, $0.97 ($0.19-13.55). Total cost of medication (including co-medications) with ACT averaged $3.64 (95% CI; $3.53-3.75) per prescription, about twice the mean cost of treatment with monotherapy, $1.83 (95% CI; $1.57-2.1). Highest proportion 46.5% (614), of the anti-malarial drugs was dispensed to patients for self-treatment. Treatment by retail outlets accounted for 35.8% while 17.7% of the drugs were dispensed from hospital prescriptions. Self-medication, 82%, accounted for the highest source of monotherapy and a majority of prescriptions, 85.6%, was adults. CONCLUSION: Findings suggest vastly improved use of ACT in the retail sector after eight years of policy change, with significant contributions from AMFm drugs. However the use of monotherapy, particularly through self-medication remains significant with increasing risk of undermining treatment policy, suggesting additional measures to directly target consumers and providers in the sector for improved use of anti-malarial drugs in Nigeria.

Larvicidal and phytochemical properties of Callistemon rigidus R. Br. (Myrtaceae) leaf solvent extracts against three vector mosquitoes.

BACKGROUND & OBJECTIVES: Due to ever-growing insecticide resistance in mosquito vectors and environmental contamination by synthetic insecticides, plants may be a source of alternative agents for mosquito control. Therefore, the present investigation involved the determination of larvicidal and phytochemical properties of Callistemon rigidus leaf extracts against Anopheles gambiae, Aedes aegypti and Culex quinquefasciatus. METHODS: The standard protocol of WHO was used for larval tests. Twenty five IV instar larvae were exposed to various concentrations from 125-1000 ppm for methanol crude extract (MCE), hexane (HF), chloroform (CF), ethyl acetate (EAF) and methanol (MF) fractions, from 250-2000 ppm for aqueous extract (AE) and 2500 ppm for Diclorvos. The mortality was observed 24 h post-exposure. The LC50 and LC90 values were determined by Probit analysis. RESULTS: The phytochemical analysis revealed that the presence of alkaloids, steroids, saponins, terpenoids, tannins and phenolic compounds, lipids, fats and fixed oils in MCE; terpenoids, steroids, lipids, fats and fixed oils in HF; terpenoids in CF; tannins and phenolic compounds in EAF and alkaloids, tannins, saponins and phenolic compounds in MF. Against Ae. aegypti, HF was the most active fraction with LC50 of 56.25 ppm. Against An. gambiae, HF demonstrated its potential mosquito larvicide killing relatively all exposed larvae at all concentrations with LC50 of 17.11 ppm. Against Cx. quinquefasciatus, only MCE and HF exhibited larvicidal activity with LC50 of 447.38 and 721.95 ppm, respectively. INTERPRETATION & CONCLUSION: Callistemon rigidus exhibited some promising larvicidal activity against medically important vector mosquitoes. Studies are indicated to identify the active compounds from this plant for developing mosquito larvicides.

Azadirachta indica extract-artesunic acid combination produces an increased cure rate of Plasmodium berghei-infected mice.

CONTEXT: Available artemisinin-combination therapies (ACTs) are expensive. Various traditional herbal remedies for malaria involve plants, proven scientifically to have antiplasmodial effects, e.g., Azadirachta indica A. Juss. (Meliaceae). OBJECTIVE: Combination of an artemisinin-based compound and a medicinal herb extract will provide an indigenous alternative/herb-based ACT. MATERIALS AND METHODS: The in vivo schizontocidal activity of the crude aqueous extract of 100, 500, and 1000 mg/kg of A. indica fresh leaves (NCE) and 6, 15, and 20 mg/kg of artesunic acid were determined, alone and in combination, while keeping the dose of artesunic acid constant at 15 mg/kg, using the Peter's 4-day suppressive test and Swiss albino mice. The ED50 was calculated from the dose-response relationships. Percentage survival and cure were also determined. RESULTS: The average yield of two extractions of NCE was 8.33 ± 1.67%. Combination of 1000 mg/kg of NCE and 15 mg/kg of artesunic acid, produced a significant reduction of parasitemia (96.87%), compared to 20 mg/kg of artesunic acid alone (68.14%). The combination had an ED50 of 0.58 mg/kg while that of artesunic acid alone was 8.814 mg/kg. The combinations of NCE with artesunic acid produced a cure, although the artesunic acid did not produce a cure in 30 d. DISCUSSION: NCE increased the activity of artesunic acid in terms of reduction in parasitemia, and increased survival time and cure rate. CONCLUSION: The combination of an artemisinin and aqueous extract of neem leaf is possible, providing a potentiated reduction of parasitemia, and increased cure rate.

In vitro antiplasmodial and anticancer analyses of endophytic fungal extracts isolated from selected Nigerian medicinal plants.

Ethnomedicinal plants are thought to have better prospects of harboring endophytes that produce natural products with pharmacological activities. This study aimed to investigate the antiplasmodial and anticancer properties of secondary metabolites of endophytic fungi from three medicinal plants. The endophytic fungi included Lasiodiplodia theobromae isolated from Cola acuminata, Curvularia lunata Bv4 isolated from Bambusa vulgaris, and Curvularia lunata Eg7 isolated from Elaeis guineensis. The identification of the fungi was based on the internal transcribed spacer (ITS-rDNA) sequence. The fungi were subjected to solid-state fermentation and the secondary metabolites were extracted with ethyl acetate. In vitro antiplasmodial screening of extracts was performed using the SYBR green I-based fluorescence assay on the chloroquine-resistant Plasmodium falciparum strain DD2. The cytotoxicity of the extracts on human red blood cells and Jurkat (leukemia) cells was assessed using the tetrazolium-based colorimetric MTT assay. Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the constituents of the fungal extracts. The extract of L. theobromae showed the best antiplasmodial activity against chloroquine-resistant P. falciparum (IC50 = 5.4 µg/mL) and was not harmful to erythrocytes (CC50 > 100 µg/mL). All three fungal extracts showed a weak cytotoxic effect against Jukart cell lines (CC50 > 100 µg/mL). GC-MS analysis of the three endophytic fungal extracts revealed the presence of forty major bioactive compounds, including: oxalic acid, isobutyl nonyl ester, 2,4-di-tert-butylphenol, and hexadecanoic acid, among others. The endophytic fungi from the medicinal plants in this study were promising sources of bioactive compounds that could be further evaluated as novel drugs for the treatment of malaria caused by P. falciparum-resistant strains.

Evaluating Malaria Rapid Diagnostic Tests and Microscopy for Detecting Plasmodium Infection and Status of Plasmodium falciparum Histidine-Rich Protein 2/3 Gene Deletions in Southeastern Nigeria.

Delays in malaria diagnosis increase treatment failures and deaths. In endemic regions, standard diagnostic methods are microscopy and malaria rapid diagnostic tests (mRDTs) detecting Plasmodium falciparum histidine-rich protein 2/3 (PFHRP2/PFHRP3), but gene deletions can allow certain parasites to remain undetected. We enlisted a cohort comprising 207 symptomatic individuals, encompassing both children and adults, at a hospital in Nnewi, Nigeria. The prevalence of parasites was determined using a highly sensitive, species-specific quantitative polymerase chain reaction (SS-qPCR). Within a subset of 132 participants, we assessed the sensitivity and specificity of microscopy and HRP2-mRDTs in comparison to SS-qPCR for the detection of P. falciparum. We also investigated the prevalence of pfhrp2/pfhrp3 gene deletions. Greater sensitivity was achieved with mRDTs (95%) compared with microscopy (77%). Also, mRDTs exhibited greater specificity (68%) than microscopy (44%). The positive predictive value of mRDTs (89%) surpassed that of microscopy (80%), suggesting a greater probability of accurately indicating the presence of infection. The negative predictive value of mRDTs (82%) was far greater than microscopy (39%). Of the 165 P. falciparum-positive samples screened for pfhrp2/pfhrp3 gene deletions, one gene deletion was detected in one sample. Regarding infection prevalence, 84% were positive for Plasmodium spp. (by reverse transcription [RT]-qPCR), with P. falciparum responsible for the majority (97%) of positive cases. Thus, exclusive reliance on microscopy in endemic areas may impede control efforts resulting from false negatives, underscoring the necessity for enhanced training and advocating for high-throughput molecular testing such as RT-qPCR or qPCR at referral centers to address limitations.

Luteinizing Hormone-Releasing Hormone (LHRH)-Conjugated Cancer Drug Delivery from Magnetite Nanoparticle-Modified Microporous Poly-Di-Methyl-Siloxane (PDMS) Systems for the Targeted Treatment of Triple Negative Breast Cancer Cells.

This study presents LHRH conjugated drug delivery via a magnetite nanoparticle-modified microporous Poly-Di-Methyl-Siloxane (PDMS) system for the targeted suppression of triple-negative breast cancer cells. First, the MNP-modified PDMS devices are fabricated before loading with targeted and untargeted cancer drugs. The release kinetics from the devices are then studied before fitting the results to the Korsmeyer-Peppas model. Cell viability and cytotoxicity assessments are then presented using results from the Alamar blue assay. Apoptosis induction is then elucidated using flow cytometry. The in vitro drug release studies demonstrated a sustained and controlled release of unconjugated drugs (Prodigiosin and paclitaxel) and conjugated drugs [LHRH conjugated paclitaxel (PTX+LHRH) and LHRH-conjugated prodigiosin (PG+LHRH)] from the magnetite nanoparticle modified microporous PDMS devices for 30 days at 37 °C, 41 °C, and 44 °C. At 24, 48, 72, and 96 h, the groups loaded with conjugated drugs (PG+LHRH and PTX+LHRH) had a significantly higher (p < 0.05) percentage cell growth inhibition than the groups loaded with unconjugated drugs (PG and PTX). Additionally, throughout the study, the MNP+PDMS (without drug) group exhibited a steady rise in the percentage of cell growth inhibition. The flow cytometry results revealed a high incidence of early and late-stage apoptosis. The implications of the results are discussed for the development of biomedical devices for the localized and targeted release of cancer drugs that can prevent cancer recurrence following tumor resection.

Immunoglobulin G (IgG) specific responses to recombinant Qß displayed MSP3 and UB05 in plasma of asymptomatic Plasmodium falciparum-infected children living in two different agro-ecological settings of Cameroon.

Introduction: in areas with intense perennial malaria transmission, limited data is available on the impact of environmental conditions especially rainfall on naturally acquired immunity against promising malaria vaccine candidates. For this reason, we have compared IgG antibody responses specific to Plasmodium spp. derived MSP3 and UB05 vaccine candidates, in plasma of children living in two areas of Cameroon differing in rainfall conditions. Methods: data about children less than 5 years old was collected during the years 2017 and 2018. Next malaria asymptomatic P. falciparum (Pf) infected children were selected following malaria test confirmation. MSP3 and UB05 specific IgG antibody responses were measured in participant´s plasma using enzyme-linked immunosorbent assay (ELISA). Results: interestingly, IgG antibody responses specific to UB05 were significantly higher (p<0.0001) in Pf-negative children when compared to their asymptomatic Pf-infected counterparts living in monomodal rainfall areas. In contrast, a significantly higher (p<0.0001) IgG response to MSP3 was observed instead in asymptomatic Pf-infected children in the same population. In addition, IgG responses specific to UB05 remained significantly higher in bimodal when compared to monomodal rainfall areas irrespective of children´s Pf infection status (p<0.0055 for Pf-positive and p<0.0001 for negative children). On the contrary, IgG antibody responses specific to MSP3 were significantly higher in bimodal relative to monomodal rainfall areas (P<0.0001) just for Pf-negative children. Conclusion: thus IgG antibody responses specific to UBO5 are a better correlate of naturally acquired immunity against malaria in Pf-negative Cameroonian children especially in monomodal rainfall areas.

Effects of Zingiber officinale on the plasma pharmacokinetics and lung penetrations of ciprofloxacin and isoniazid.

The study was carried out to determine the effect of ginger on the plasma pharmacokinetics of ciprofloxacin and Isoniazid in a rat model in phase 1. The effects of the herb on the penetration of ciproflacin and Isoniazid into the lung tissues were also determined in phase 2. In phase 1, Albino rats of both sexes (n = 20) were divided into 4 groups of 5 rats per group. Two groups received oral ciprofloxacin (20 mg/kg) and isoniazid (15 mg/kg). Other groups were fed with ginger (5 mg/kg) for 10 days followed by the drug administration on the 11th day. Blood samples were collected from each group at 0-, 0.5-, 1-, 2-, 5-, 8-, 12-, and 24-hour intervals. Plasma concentrations of the drugs were determined by a spectrophotometric method and the pharmacokinetic parameters determined using noncompartmental method as implemented in the winNonlin program. In phase 2, where the effects of the herb on the penetration of the drugs were determined, the concentrations of ciprofloxacin and isoniazid attained in the lung fluid of rats in the presence and absence of the herb were compared after a single oral dose of the drugs used in the same dose range as in phase 1. In the first phase, treatment with ginger significantly increased the area under the concentration-time curve of ciprofloxacin, whereas Vz and Cl were decreased. Ginger significantly decreased the area under the concentration-time curve of isoniazid, whereas Vz and Cl were increased. Ginger enhanced the penetration of ciprofloxacin and Isoniazid into the lung tissues; however, their rates of penetration were delayed.