Browsing by Author "Adjimani, J.P."
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Item Antioxidant and free radical scavenging activity of ironchelators(Elsevier B.V., 2015-05-11) Adjimani, J.P.; Asare, P.Inside the human body, reactive derivatives of oxygen, known as reactive oxygen species(ROS) such as the superoxide radical (O2•), hydroxyl radical (•OH) and hydrogen perox-ide (H2O2), are constantly generated. The ROS easily cause oxidative damage to variousbiomolecules such as proteins, lipids and DNA leading to various disease conditions. Ironchelators function as antioxidants by scavenging ROS and also reduce the amount of avail-able iron thereby decreasing the quantity of•OH generated by Fenton reactions. In thisstudy, the antioxidant activity of the iron chelators: caffeic acid (CA), 2,3-dihydroxybenzoicacid (DHBA), desferroxamine B (FOB) and benzohydroxamic acid (BHA) were determinedusing five different in vitro antioxidant assays. The antioxidant assays used were: ironbinding ability, reducing ability using the potassium ferricyanide reduction method, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, H2O2scavenging activityand•OH scavenging activity. The standard used for the iron binding ability was Na2EDTAwhereas vitamin C was used as a standard for the remaining assays. The iron chelatorsshowed a concentration dependent increase in their radical scavenging activities as wellas their reducing ability. At the concentration of 1 mM, FOB had the highest iron bindingability of 93.7% whereas DHBA had the lowest iron binding ability of 5.0% compared to thestandard Na2EDTA which had 94.8%. The iron chelators, with the exception of BHA, showedgood reducing ability than vitamin C. Caffeic acid showed significant DPPH, hydrogen per-oxide and hydroxyl radical scavenging activities of 84.7%, 99.8% and 14.5%, respectively. Allthe iron chelators were observed to show significant activities in all five antioxidant assays.Item Detection and characterization of human rotavirus in tap water by multiplex RT-PCR(Journal of Medicine and Medical Sciences, 2010) Tieroyaare, D.J.; Adjimani, J.P.; Armah, G.E.More than a billion diarrheal cases occur each year among children below five years resulting in high morbidity and mortality. Rotaviruses, the single leading cause of diarrhea in children below five years, cause more than 130 million episodes of severe diarrhea throughout the world. While treated water has been identified as a route of transmission, rotavirus in treated water has not been investigated in Ghana. Since the presence of rotaviruses in drinking water is unacceptable, a virological survey to detect and characterize rotavirus was conducted on tap water in the western part of Accra. Treated water samples were collected from five zones within the distribution network of Weija Water Works. Two litres of each sample were concentrated 4,000 fold and the viral particles extracted. Viral RNA was extracted from all concentrates using phenol/chloroform, purified with the RNaid®kit and reverse transcribed. The cDNA was amplified by semi-nested PCR using P and G genotype-specific primers and analyzed an agarose gel. Rotavirus was detected in 48.1% of samples. Nine rotavirus P-types and 12 G-types were detected. The detection pattern showed increased viral pollution with distance from the treatment plant and in areas with high human activity.Item In vitro activity and mode of action of phenolic compounds on Leishmania donovani(PLoS Neglected Tropical Diseases, 2019-02) Antwi, C.A.; Amisigo, C.M.; Adjimani, J.P.; Gwira, T.M.Background Leishmaniasis is a disease caused by the protozoan parasite, Leishmania. The disease remains a global threat to public health requiring effective chemotherapy for control and treatment. In this study, the effect of some selected phenolic compounds on Leishmania donovani was investigated. The compounds were screened for their anti-leishmanial activities against promastigote and intracellular amastigote forms of Leishmania donovani. Methodology/Principal findings The dose dependent effect and cytotoxicity of the compounds were determined by the MTT assay. Flow cytometry was used to determine the effect of the compounds on the cell cycle. Parasite morphological analysis was done by microscopy and growth kinetic studies were conducted by culturing cells and counting at 24 hours intervals over 120 hours. The cellular levels of iron in promastigotes treated with compounds was determined by atomic absorption spectroscopy and the effect of compounds on the expression of iron dependent enzymes was investigated using RT-qPCR. The IC50 of the compounds ranged from 16.34 μM to 124 μM compared to amphotericin B and deferoxamine controls. Rosmarinic acid and apigenin were the most effective against the promastigote and the intracellular amastigote forms. Selectivity indexes (SI) of rosmarinic acid and apigenin were 15.03 and 10.45 respectively for promastigotes while the SI of 12.78 and 5.20 respectively was obtained for intracellular amastigotes. Morphologically, 70% of rosmarinic acid treated promastigotes showed rounded morphology similar to the deferoxamine control. About 30% of cells treated with apigenin showed distorted cell membrane. Rosmarinic acid and apigenin induced cell arrest in the G0/G1 phase in promastigotes. Elevated intracellular iron levels were observed in promastigotes when parasites were treated with rosmarinic acid and this correlated with the level of expression of iron dependent genes. Conclusions/Significance The data suggests that rosmarinic acid exerts its anti-leishmanial effect via iron chelation resulting in variable morphological changes and cell cycle arrest.Item In vitro anti-trypanosomal effects of selected phenolic acids on Trypanosoma brucei(PLoS ONE, 2019-05) Amisigo, C.M.; Antwi, C.A.; Adjimani, J.P.; Gwira, T.M.African trypanosomiasis remains a lethal disease to both humans and livestock. The disease persists due to limited drug availability, toxicity and drug resistance, hence the need for a better understanding of the parasite’s biology and provision of alternative forms of therapy. In this study, the in vitro effects of phenolic acids were assessed for their trypanocidal activities against Trypanosoma brucei brucei. The effect of the phenolic acids on Trypanosoma brucei brucei was determined by the alamarBlue assay. The cell cycle effects were determined by flow cytometry and parasite morphological analysis was done by microscopy. Effect on cell proliferation was determined by growth kinetic analysis. Reverse Transcriptase quantitative Polymerase Chain Reaction was used to determine expression of iron dependent enzymes and iron distribution determined by atomic absorption spectroscopy. Gallic acid gave an IC50 of 14.2±1.5 μM. Deferoxamine, gallic acid and diminazene aceturate showed a dose dependent effect on the cell viability and the mitochondrion membrane integrity. Gallic acid, deferoxamine and diminazene aceturate caused loss of kinetoplast in 22%, 26% and 82% of trypanosomes respectively and less than 10% increase in the number of trypanosomes in S phase was observed. Gallic acid caused a 0.6 fold decrease, 50 fold increase and 7 fold increase in the expression levels of the transferrin receptor, ribonucleotide reductase and cyclin 2 genes respectively while treatment with deferoxamine and diminazene aceturate also showed differential expressions of the transferrin receptor, ribonucleotide reductase and cyclin 2 genes.Item Is there any relationship between haptoglobin phenotypes and retinopathy among Ghanaian diabetics?(Springer, 2009) Adinortey, M.B.; Gyan, B.A.; Adjimani, J.P.; Nyarko, P.E.; Nyarko, A.In this study, differences in lipid levels amongst diabetics with and without complications were assessed to determine lipid disorders that are associated with diabetic complications other than cardiovascular diseases. A Cross sectional study design was employed. The study included 288 diabetics and 108 non diabetics with different types of complications such as hypertension, nephropathy, neuropathy, and retinopathy. The mean serum total cholesterol was higher in patients with complications compared to those without complications and the non-diabetic controls. The normotensive diabetic patients had the lowest total cholesterol among the diabetic patients’ groups (4.65 ± 0.17 mmol/l) compared to the diabetics with hypertension (6.051 ± 0.20 mmol/l), retinopathy (6.26 ± 0.29 mmol/l), neuropathy (5.80 ± 0.17 mmol/l) and nephropathy patients 5.74 ± 0.26 mmol/l (P < 0.05). The prevalence of dyslipidaemia among diabetic subjects was between 19.2 and 84.0%. The study shows that, in addition to macrovascular complications, dyslipidaemia is common in type 2 diabetes mellitus patients with microvascular complications.Item Levels of soluble CD163 and severity of malaria in children in Ghana(Clinical Vaccine Immunology 15(9):1456-60, 2008) Kusi, K.A.; Gyan, B.A.; Goka, B.Q.; Dodoo, D.; Obeng-Adjei, G.; Troye-Blomberg, M.; Akanmori, B.D.; Adjimani, J.P.CD163 is an acute-phase-regulated monocyte/macrophage membrane receptor expressed late in inflammation. It is involved in the haptoglobin-mediated removal of free hemoglobin from plasma, has been identified as a naturally soluble plasma glycoprotein with potential anti-inflammatory properties, and is possibly linked to an individual's haptoglobin phenotype. High levels of soluble CD163 (sCD163) in a malaria episode may therefore downregulate inflammation and curb disease severity. In order to verify this, the relationships between sCD163 levels, malaria severity, and selected inflammatory mediators (tumor necrosis factor alpha [TNF-alpha], interleukin-6 [IL-6], and IL-10) were assessed by enzyme-linked immunosorbent assay using plasma samples obtained from pediatric malaria patients with uncomplicated malaria (UM [n = 38]), cerebral malaria (CM [n = 52]), and severe malarial anemia (SA [n = 55]) during two consecutive malaria transmission seasons (2002 and 2003). Median sCD163 levels were higher in UM (11.9 microg/ml) patients than in SA (7.7 microg/ml; P = 0.010) and CM (8.0 microg/ml; P = 0.031) patients. Levels of sCD163 were also higher in all patient groups than in a group of 81 age-matched healthy controls. The higher sCD163/TNF-alpha ratio in UM patients, coupled with the fact that sCD163 levels correlated with TNF-alpha levels in UM patients but not in CM and SA patients, suggests inflammatory dysregulation in the complicated cases. The study showed that sCD163 levels are elevated during acute malaria. High sCD163 levels in UM patients may be due to the induction of higher-level anti-inflammatory responses, enabling them to avoid disease complications. It is also possible that UM patients simply lost their CD163 receptors from macrophages in inflammatory sites while complicated-malaria patients still had their receptors attached to activated macrophages, reflecting ongoing and higher-level inflammation associated with complicated malaria.Item Levels of Soluble CD163 and Severity of Malaria in Children in Ghana(Clin. Vaccine Immunol 15(9): 1456–1460, 2008) Kusi, K. A; Gyan, B.A; Goka, B.Q; Dodoo, D.; Obeng-Adjei, G.; Troye-Blomberg, M.; Akanmori, B.D.; Adjimani, J.P.CD163 is an acute-phase-regulated monocyte/macrophage membrane receptor expressed late in inflammation. It is involved in the haptoglobin-mediated removal of free hemoglobin from plasma, has been identified as a naturally soluble plasma glycoprotein with potential anti-inflammatory properties, and is possibly linked to an individual's haptoglobin phenotype. High levels of soluble CD163 (sCD163) in a malaria episode may therefore downregulate inflammation and curb disease severity. In order to verify this, the relationships between sCD163 levels, malaria severity, and selected inflammatory mediators (tumor necrosis factor alpha [TNF-alpha], interleukin-6 [IL-6], and IL-10) were assessed by enzyme-linked immunosorbent assay using plasma samples obtained from pediatric malaria patients with uncomplicated malaria (UM [n = 38]), cerebral malaria (CM [n = 52]), and severe malarial anemia (SA [n = 55]) during two consecutive malaria transmission seasons (2002 and 2003). Median sCD163 levels were higher in UM (11.9 microg/ml) patients than in SA (7.7 microg/ml; P = 0.010) and CM (8.0 microg/ml; P = 0.031) patients. Levels of sCD163 were also higher in all patient groups than in a group of 81 age-matched healthy controls. The higher sCD163/TNF-alpha ratio in UM patients, coupled with the fact that sCD163 levels correlated with TNF-alpha levels in UM patients but not in CM and SA patients, suggests inflammatory dysregulation in the complicated cases. The study showed that sCD163 levels are elevated during acute malaria. High sCD163 levels in UM patients may be due to the induction of higher-level anti-inflammatory responses, enabling them to avoid disease complications. It is also possible that UM patients simply lost their CD163 receptors from macrophages in inflammatory sites while complicated-malaria patients still had their receptors attached to activated macrophages, reflecting ongoing and higher-level inflammation associated with complicated malaria.Item Mechanism of Antimalarial Action of Desferrioxamine B(University of Ghana, 2000-01) Aryee, R.N.A.; Armah, G.E.; Adjimani, J.P.; University of Ghana, College of Basic and Applied Sciences, School of Biological Sciences, Department of Biochemistry, Cell and Molecular Biology.Desferrioxamine B was shown to exhibit potent antimalaria activity. A single bolus injection of lOOmg of desferrioxamine B per kilogram body weight of mice reduced Plasmodium berghei anka parasitemia in CBA mice for 24 hours. Peripheral blood samples of desferrioxamine B-treated mice taken at 0, 3, 6, 12, 24 and 48 hours after drug administration show gross adverse ultrastructural changes in all developmental stages of the malaria parasite (trophozoites, schizonts and gametocytes) and a reduction in parasite numbers. The iron chelator was also found to function as an inhibitor of heme polymerisation by binding to and immobilising the central ferric ion of parasite-associated heme and hence disrupting heme detoxification into hemozoin It was concluded that desferrioxamine B is active against Plasmodium berghei anka and that iron chelation provides a new possible alternate strategy for the treatment of malaria.Item Natural antioxidants attenuate mycolactone toxicity to RAW 264.7 macrophages(Experimental Biology and Medicine, 2021) Kwaffo, Y.A.; Sarpong-Duah, M.; Owusu-Boateng, K.; Gbewonyo, W.S.K; Adjimani, J.P.; Mosi, L.Mycobacterium ulcerans produces a macrolide exotoxin, mycolactone which suppresses immune cells activity, is toxic to most cells and the key virulence factor in the pathogenesis of Buruli ulcer disease. Mycolactone is reported to mediate the production of reactive oxygen species in keratinocytes; cells that play critical role in wound healing. Increased levels of reactive oxygen species have been shown to disrupt the well-ordered process of wound repair; hence, the function of wound-healing cells such as macrophages, keratinocytes, and fibroblast could be impaired in the presence of the reactive oxygen species mediator, mycolactone. To ensure regeneration of tissues in chronic ulcers, with proper and timely healing of the wounds, natural antioxidants that can combat the effects of induced reactive oxygen species in wound-healing cells ought to be investigated. Reactive oxygen species activity was determined in mycolactone-treated RAW 264.7 macrophages and the scavenging ability of the antioxidants (ascorbic acid, gallic acid, and green tea kombucha) against mycolactone-induced reactive oxygen species (superoxide anions) was assessed using fluorescein probe (DCF-DA) and nitroblue tetrazolium dye. Cytotoxicity of the antioxidants, mycolactone, and the protective effect of the antioxidants on the cells upon treatment with mycolactone were determined using the Alamar blue assay. The expression levels of endogenous antioxidant enzyme genes (superoxide dismutase, catalase, and glutathione peroxidase) in response to mycolactone-mediated reactive oxygen species were determined using RT-qPCR. Mycolactone induced the production of reactive oxygen species in RAW 264.7 macrophages, and the resulting superoxide anions were scavenged by some of the antioxidants. The selected endogenous antioxidant enzyme genes in the macrophages were upregulated in the presence of the antioxidants and mycolactone. The exogenously supplied ascorbic acid and green tea kombucha offered moderate protection to the macrophages against the toxicity of mycolactone. We conclude that the results provide insights into alternate and adjunct therapeutic approaches in Buruli ulcer treatment, which could significantly attenuate the toxicity of the pathogenic factor; mycolactoneItem Phytoremediation of Some Tropical Soils Contaminated with Petroleum Crude Oil(University of Ghana, 2013-12) Oyibo, C.; Dowuona, G.N.N.N.; Danson, P.K.O.; Enukwesi, L.; Adjimani, J.P.This study was undertaken in three phases to identify (phase 1), screen (phase 11) and evaluate (phase 111) plants for their phytoremediation potential. In Phase 1, 15 plant species made up of grasses and legumes namely: Paspalum. vaginatum, Cynodon.dactylon, Pueraria. phaseoloides, Centrosema. pubescens, Panicum. maximum, Schrankia. leptocarpa, Eclipta. alba (Linn.), Cyperus. haspen (Linn.), Melastromastrum. capitatum, Acreceras. zizanoides Dandy, Pteridum aquilinum (Linn), Ludwigia.decurrens Walt,Setaria longiseta P.Beauv., Physalis angulata (Linn.), and Desmodium scorpiurus Desv.were identified on sites previously polluted by crude oil spills in the Niger Delta Area of Nigeria. The first 6 species were used in phase 11 while the first four species were earmarked (rolled over) for phase 111. Responses to Questionnaire indicated that majority of residents in the selected sites/communities had lived in these areas for 10 or more years had mainly JHS/SHS education; were self employed – mainly farmers and fishers although most were unemployed in the public sector. Adverse effects of the operations of oil companies particularly oil spillage on the environment and local residents include: loss of vegetation and farmlands, soil and water body contamination, weak social and cultural institutions (disrespect by youth for elders and institutions), militancy and hostage taking among youth from the area. In phase 11, seeds of legumes among the six selected species were collected from Accra, Aburi environs and Kusi in the Eastern region of Ghana; they were scarified, cultured in growth medium and the seedlings which emerged from them were transplanted into experimental pots, each containing 2000g of either Alajo or Toje soil series. One week after transplanting, each pot was simulated with a corresponding serial crude oil concentration of 0% (control) 1 % (24ml), 3% (83ml), 5.5% (130ml) and 8% (189ml) or 10% (237ml) in three replicates. These concentrations were arrived at, using the fomular [(vol of crude = % X wt / 0.844) ml]. Similarly, three replicates of each selected grass species were planted vegetatively into 2000g of either Alajo or Toje soil series using known numbers of propagules (stolons). After one week of planting, pots were treated with the above serial crude oil concentrations using the appropriate volume indicated. Germination rates were variable and results of percentage plant Survival Difference (PSD) indicated that Paspalum vaginatum and Cynodon dactylon were highly tolerant of crude oil concentrations at 3%, 5.5% and 8% on the Toje soil series and 3%, 5.5% and 10% on the Alajo soil series as compared to Panicum maximum and where therefore selected as high contaminant tolerant species for phase 111; whereas Puraria phaseoloides and Centrosema pubescens which had - 45% & ±42% and -16% & -35%respectively, as PSD for Alajo and Toje soil series as compared to Schrankia leptocarpa, were also selected as low/poor contaminant tolerant species (at 1% & 2% - introduced in phase 111as upper contamination limit for the poor tolerant species) also, for the last stage (phase 111) of the study. For phase 111, C. dactylon, P .vaginatum, P. phaseoloides and C. pubescens were evaluated for phytoremediation potential at crude oil concentrations of 3%, 5.5% (added to determine mid-point tolerance for high contamination tolerant species) and 8% for Toje soil series, and going up to 10% for Alajo soil series for high contaminant tolerant species and 1% & 2% for low/poor tolerant species respectively, using the randomized complete block design. Results of plant biomass (fresh weight) decreased (between 0.5g/fw & 20g/fw) at low contaminant concentrations and increased (between 14g/fw & 122g/fw) at high contaminant concentrations.Values of plant enrichment were higher for Cynodon dactylon (0.9% & 4.49%) than for Paspalum vaginatum (1.2% & 3.12%) respectively for Toje and Alajo soil series. Therefore, both Cynodon dactylon and Paspalum vaginatum can be good plants species for phytoremediation having accumulated total hydrocarbons up to 33,270mg/kg at 5.5% on Toje soil series and 40,466mg/kg at 8% on Alajo soil series.