G. I Olasehinde

In-vitro studies on the sensitivity pattern of Plasmodium falciparum to antimalarial drugs and local herbal extracts

BackgroundThe resistance of human malaria parasites to anti-malarial compounds has become considerable concern, particularly in view of the shortage of novel classes of anti-malarial drugs. One way to prevent resistance is by using new compounds that are not based on existing synthetic antimicrobial agents.ResultsSensitivity of 100 Plasmodium falciparum isolates to chloroquine, quinine, amodiaquine, mefloquine, sulphadoxine/pyrimethamine, artemisinin, Momordica charantia (‘Ejirin’) Diospyros monbuttensis (‘Egun eja’) and Morinda lucida (‘Oruwo’) was determined using the in vitro microtest (Mark III) technique to determine the IC50 of the drugs. All the isolates tested were sensitive to quinine, mefloquine and artesunate. Fifty-one percent of the isolates were resistant to chloroquine, 13% to amodiaquine and 5% to sulphadoxine/pyrimethamine. Highest resistance to chloroquine (68.9%) was recorded among isolates from Yewa zone while highest resistance to amodiaquine (30%) was observed in Ijebu zone. Highest resistance to sulphadoxine/pyrimethamine was recorded in Yewa and Egba zones, respectively. A positive correlation was observed between the responses to artemisinin and mefloquine (P<0.05), artemisinin and quinine (P<0.05) and quinine and mefloquine (P<0.05). A negative correlation was observed between the responses to chloroquine and mefloquine (P>0.05). Highest anti-plasmodial activity was obtained with the ethanolic extract of D. monbuttensis (IC50 = 3.2nM) while the lowest was obtained from M. lucida (IC50 =25nM).ConclusionsNatural products isolated from plants used in traditional medicine, which have potent anti-plasmodial action in vitro, represent potential sources of new anti-malarial drugs.

Computational and experimental analysis identified 6-diazo-5-oxonorleucine as a potential agent for treating infection by Plasmodium falciparum

Plasmodium falciparum (PF) is the most severe malaria parasite. It is developing resistance quickly to existing drugs making it indispensable to discover new drugs. Effective drugs have been discovered targeting metabolic enzymes of the parasite. In order to predict new drug targets, computational methods can be used employing database information of metabolism. Using this data, we performed recently a computational network analysis of metabolism of PF. We analyzed the topology of the network to find reactions which are sensitive against perturbations, i.e., when a single enzyme is blocked by drugs. We now used a refined network comprising also the host enzymes which led to a refined set of the five targets glutamyl-tRNA (gln) amidotransferase, hydroxyethylthiazole kinase, deoxyribose-phophate aldolase, pseudouridylate synthase, and deoxyhypusine synthase. It was shown elsewhere that glutamyl-tRNA (gln) amidotransferase of other microorganisms can be inhibited by 6-diazo-5-oxonorleucine. Performing a half maximal inhibitory concentration (IC50) assay, we showed, that 6-diazo-5-oxonorleucine is also severely affecting viability of PF in blood plasma of the human host. We confirmed this by an in vivo study observing Plasmodium berghei infected mice.

Enhanced antioxidant capacity following selenium supplemented antimalarial therapy in Plasmodium berghei infected mice

The effect of the co-administration of artemether, lumefantrine and selenium was studied in mice infected with Plasmodium bergheiparasite. The mice were divided into seven groups of six animals per group. All groups except A were parasitized. Group A (unparasitized/untreated) and B (parasitized/untreated) served as the positive and negative control respectively, these were administered with olive oil. Animals in groups C and D were treated with 8 and 48 mg/kg/bw of artemether and lumefantrine respectively while group E was treated with a combination of artemether and lumefantrine (8: 48 mg/kg/bw). Animals in group F were treated with 0.945 mg/kg/bw of selenium only and group G was treated with a combination of artemether, lumefantrine and selenium (8:48:0.945 mg/kg/bw). All the treatment was done for a three day period. These animals were subsequently anaesthetized and the organs were excised. Homogenates were prepared for aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total protein, reduced Glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) assays. The results showed a significant (p<0.05) difference in the levels of ALP and MDA in group B, while a significant difference was observed in the levels of ALP, total protein, CAT and MDA in group G when compared with the parasitized group. Histopathological analysis showed no presence of inflammatory cells in group G when compared with group B. It may be concluded that the combination of artemether, lumefantrine and selenium showed a more potent effect against the parasite than the group treated with artemether and lumefantrine, thus, helps to combat post-infection oxidative stress in susceptible cells.The effect of the co-administration of artemether, lumefantrine and selenium was studied in mice infected with Plasmodium bergheiparasite. The mice were divided into seven groups of six animals per group. All groups except A were parasitized. Group A (unparasitized/untreated) and B (parasitized/untreated) served as the positive and negative control respectively, these were administered with olive oil. Animals in groups C and D were treated with 8 and 48 mg/kg/bw of artemether and lumefantrine respectively while group E was treated with a combination of artemether and lumefantrine (8: 48 mg/kg/bw). Animals in group F were treated with 0.945 mg/kg/bw of selenium only and group G was treated with a combination of artemether, lumefantrine and selenium (8:48:0.945 mg/kg/bw). All the treatment was done for a three day period. These animals were subsequently anaesthetized and the organs were excised. Homogenates were prepared for aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphat...

Cardiovascular Risk Factors in a Suburban Community in Nigeria

The burden of hypertension, a silent killer, continues to increase in low- and middle-income countries. This study evaluated blood pressure (BP) in healthy adults to determine their risk of developing hypertension and to reduce associated morbidity of the disease. Overall, 182 subjects aged >16 years participated in the study. Systolic (SBP) and diastolic blood pressure (DBP) was measured after a resting period using mercury sphygmomanometer. Random blood glucose (RBG) concentration was also determined. Regression models were used to determine risk of high BP with p values < 0.05 indicating statistical difference. Prehypertension was present in 36.8% population and high BP in 31% individuals with hypertensive symptoms. DBP ≥ 90 mmHg was prevalent in the undiagnosed group, while diabetes comorbidity was detected in only 4 individuals. High BP or diabetes was not detected in those <20 year olds. Age > 35 years was an independent risk (likelihood ratio: 22.56, p < 0.0001); this increases to 26.48 (p < 0.0001) in the presence prediabetes and RBG > 100 mg/dl. Undiagnosed hypertension rate is high in the study area, and urgent interventions for large scale screening and management of the disease are required to reduce the burden of hypertension in Nigeria.

Data set on Rapid Diagnostic Tests (RDTs) and Microscopy for Diagnosing Plasmodium falciparum And Plasmodium vivax

The World Heal Organization (WHO) has identified malaria diagnosis as being pivotal to eradicating the disease by 2030 as stipulated in the Sustainable Development Goals (SDG). The data presented here was obtained from outpatients of a hospital in the South Western Region of Nigeria from November 2016 to May 2017. The data contains malaria incidence amongst asymptomatic and symptomatic outpatients in the period under review. Malaria incidence was obtained using two diagnostic test kits, Bioline SD (HRP-2) and ACON (HRP-2/Aldolase) alongside Microscopy as gold standard. Specificity, Sensitivity and Kappa statistic of each test device is presented in the tables herewith. Data presented here could be used alongside other data sources to assess the state of malaria diagnostics.

Efficiency of histidine rich protein II-based rapid diagnostic tests for monitoring malaria transmission intensities in an endemic area

In recent years there has been a global decrease in the prevalence of malaria due to scaling up of control measures, hence global control efforts now target elimination and eradication of the disease. However, a major problem associated with elimination is asymptomatic reservoir of infection especially in endemic areas. This study aims to determine the efficiency of histidine rich protein II (HRP-2) based rapid diagnostic tests (RDT) for monitoring transmission intensities in an endemic community in Nigeria during the pre-elimination stage. Plasmodium falciparum asymptomatic malaria infection in healthy individuals and symptomatic cases were detected using HRP-2. RDT negative tests were re-checked by microscopy and by primer specific PCR amplification of merozoite surface protein 2 (msp-2) for asexual parasites and Pfs25 gene for gametocytes in selected samples to detect low level parasitemia undetectable by microscopy. The mean age of the study population (n=280) was 6.12 years [95% CI 5.16 – 7.08, range 0.5 – 55], parasite prevalence was 44.6% and 36.3% by microscopy and RDT respectively (p =0.056). The parasite prevalence of 61.5% in children aged >2 – 10 years was significantly higher than 3.7% rate in adults >18years (p < 0.0001, χ2 = 60.45). RDT detected additional 29.6% asymptomatic cases but a lower specificity of 68.8% in symptomatic carriers. In 15 selected RDT positive samples, only 6 were positive by PCR and no gametocyte was detected. The results indicate that HRP-2 RDTs are a vital tool for understanding transmission dynamics and detecting immune-suppressed, recent and asymptomatic infections, thus crucial to tackle low level transmission and eliminating malaria in endemic areas.In recent years there has been a global decrease in the prevalence of malaria due to scaling up of control measures, hence global control efforts now target elimination and eradication of the disease. However, a major problem associated with elimination is asymptomatic reservoir of infection especially in endemic areas. This study aims to determine the efficiency of histidine rich protein II (HRP-2) based rapid diagnostic tests (RDT) for monitoring transmission intensities in an endemic community in Nigeria during the pre-elimination stage. Plasmodium falciparum asymptomatic malaria infection in healthy individuals and symptomatic cases were detected using HRP-2. RDT negative tests were re-checked by microscopy and by primer specific PCR amplification of merozoite surface protein 2 (msp-2) for asexual parasites and Pfs25 gene for gametocytes in selected samples to detect low level parasitemia undetectable by microscopy. The mean age of the study population (n=280) was 6.12 years [95% CI 5.16 – 7.08, range...

Antimicrobial and Thermal Properties of Coating Systems Modified with ZnO Nanoparticle and its Hybrid Forms: (A Review)

This review examines the unparalleled chemical and physical properties of ZnO nanoparticles and its hybrid forms. The influence of these multifunctional materials within the polymeric matrix of organic coatings was discussed. The scanning electron microscope is seen to provide relevant information about the dispersion of the hybrid and composite coating systems. This review provides concise information about the antimicrobial and thermal stability of composites.

In vivo Antiplasmodial Activity of Crude Ethanolic and N-hexane Extracts of Moringa oleifera Leaves

This study was carried out to determine the antiplasmodial activity of leaves of Moringa oleifera. Cold extraction method was carried out on grindedleaves to prepare the crude ethanolic and n-hexane extracts. Mice models (Mus musculus) were passaged with chloroquine resistant Plasmodium berghei,which are similar in morphology, physiology and life cycle to P. falciparumthat infect humans. Stock solutions of 5mg/mL5% DMSO were prepared and the extracts wereadministered atdifferent treatment concentrations, 50mg/kg, 100mg/kgand 200mg/kg body weight over 4days. Positive and negative control groups, Chloroquine diphosphate (25mg/kg) and 5% DMSO,respectively were set up. Crude ethanolic and n-hexane extracts of M. oleiferashowed anti-plasmodial activity at the three different concentrations used. Both crude ethanolic and n-hexane extracts of M. oleiferaleaves showed a significant inhibition of parasitaemia (p < 0.05) ranging from 74.7 to 95.6% for ethanolic extract and 59.3 to 87.9% for n-hexane extract. EC50value of crude ethanolic and n-hexane extractswere 32mg/kg and 42mg/kg body weight,respectively. M.oleifera showed potential for possible future use as an alternative to some conventional drugs.© 2016 Friends Science Publishers

Microbiological assessment of the indoor air quality of a university health centre in Nigeria

The air within the healthcare environment may serve as a reservoir for microorganisms thereby contributing to the rate of infection. Regular monitoring of the microbial burden is necessary to ascertain the microbiological quality of hospital environments.

Lessons in hand washing: what we should know?

Most communicable diseases are transmitted by hand; from nosocomial to community acquired diseases. Consequently, hand washing is strictly advocated in hospital, eateries and public places where contact by hand is frequent.