Ovicidal and miracicidal activities of Calotropis procera and its green-synthesized nanotized derivative: A quest for new antifasciola agents.

Fascioliasis is an important zoonotic disease but treatment with the mainstay drugs poses challenge of parasite resistance. The aim of the study was to determine the anthelmintic efficacy of ethanolic leaf extract of Calotropis procera (CP) and its synthesized silver nanoparticles (AgNPs) against the eggs and miracidia of Fasciola species. The ethanolic extract of C. procera was used to synthesise its corresponding green-synthesis derivative using silver nitrate (CP-AgNPs). The synthesized silver nanoparticles were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Scanning Electron Microscopy/Energy Dispersive X-ray (SEM/EDX). The ova and miracidia of Fasciola spp. were exposed to 1, 2, and 4 mg/ml CP ethanolic extracts and its corresponding AgNPs. FTIR showed that the formulation was capped with compounds present in the extract. The XRD showed the crystalline property of CP-AgNPs. The SEM image showed clusters of irregularly shape nanoparticles. The ovicidal activities were concentration dependent and showed highest activities 81.02±4.03% and 92.91±1.25% in 4 mg/ml CP and CP-AgNPs respectively (p < 0.05). The LC50 of CP (1.49 mg/ml) was more than 3 folds higher than that of CP-AgNPs (0.47 mg/ml). While CP did not cause miracidia death after 60 min exposure, however, 100% miracidia death were observed within 30 min exposure in all the tested concentration with CP-AgNPs. The positive control (ABZ) only showed 100% mortality after 60 min of exposure of miracidia. The study showed that green-synthesised C. procera nanoparticles showed superior ovicidal and miracicidal activities over C. procera leaf extracts and could be a source of potential antifasciola agent.

Hospital waste incinerator bottom ash leachate induced cyto-genotoxicity in Allium cepa and reproductive toxicity in mice.

The potentials of hospital incinerator bottom ash leachate (HIBAL) to induce cyto-genotoxicity in Allium cepa and reproductive anomalies in the mouse were investigated. The leachate obtained from simulation of the bottom ash was analyzed for some physico-chemical parameters. The A. cepa, mouse sperm morphology and histopathological tests were carried out at concentrations ranging from 1% to 50% of the leachate sample. In A. cepa, HIBAL caused significant (p < 0.05) inhibition of root growth and induction of chromosomal aberrations. In the animal assays, there was 100% mortality at the 50% concentrations. The leachate caused insignificant (p > 0.05) concentration-dependent induction of various types of sperm morphology. There was accumulation of fluid in the seminiferous tubule lumen and necrosis of stem cells in the testes. These effects were believed to be provoked by the somatic and germ cell genotoxins, particularly the heavy metals in the leachate. Our finding is of environmental and public health significance.

An investigation of the disposal of dental clinical waste in Ibadan City, south-west Nigeria.

This study investigated the disposal of dental clinical waste in and from dental surgeries in Ibadan, south-west Nigeria and followed the waste trail to the rubbish tips. A questionnaire was sent to 130 dentists in dental practices in Ibadan city. Rubbish collectors and scavengers were interviewed to see if they encountered clinical dental waste. The response rate of dentists was 93%. A total of 68.6% of the dentists sampled stated that there were no special disposal facilities for the different kinds of waste materials generated in their clinics: 52.9% disposed of sharp items into the waste bins; and 77.7% said there was no special treatment/disposal of needles and other items used on patients with infectious diseases. Most practices burned their wastes in the hospital area and 73.6% said they were not aware of any rules or body to regulate dental waste disposal in Nigeria. Rubbish collectors and scavengers knew what dental rubbish looked like and tried to avoid it. The survey clearly demonstrates a failure by dentists to dispose of waste appropriately and also provides evidence that scavengers encounter the waste. There is need for the government to provide recommendations, reinforced by legislation and education, to the dental profession concerning the waste materials that they generate.

Fine specificity of anti-MSP119 antibodies and multiplicity of Plasmodium falciparum merozoite surface protein 1 types in individuals in Nigeria with sub-microscopic infection.

BACKGROUND: The absence of antibodies specific for the 19 kDa C-terminal domain of merozoite surface protein 1 (MSP119) has been associated with high-density malaria parasitaemia in African populations. The hypothesis that a high prevalence and/or level of anti-MSP119 antibodies that may inhibit erythrocyte invasion would be present in apparently healthy individuals who harbour a sub-microscopic malaria infection was tested in this study. METHODS: Plasma samples were collected from residents in a region in Nigeria hyperendemic for malaria, who had no detectable parasitaemia by microscopy. Using a competition-based enzyme-linked-immunosorbent assay with two invasion-inhibitory monoclonal antibodies (mAbs) 12.10 and 12.8, the levels and prevalence of specific antibodies were measured. The minimum multiplicity of infection was determined using PCR. The prevalence of anaemia was also measured. RESULTS: Plasma samples from 85% of individuals contained antibodies that bound to MSP119. The inhibition of mAb 12.10 binding was strongly correlated with the prevalence (Spearman correlation test, p < 0.0001) and mean titre of anti-MSP119 antibodies (Spearman correlation test, p < 0.001) in the samples. Comparing samples from individuals with multiple infection (group M) and single infection (Group S), group M contained a higher (p = 0.04) prevalence of anti-MSP119 antibodies that competed with mAb 12.10. Using a logistic regression model, it was found that the presence of antibodies competitive with mAb 12.10 was affected negatively by anaemia (p = 0.0016) and positively by the carriage of multiple parasite genotypes (p = 0.04). CONCLUSIONS: In the search for correlates of protection against malaria, which will be essential to evaluate clinical trials of malaria vaccines based on MSP1, this study examines some potential assays and the factors that need to taken into account during their evaluation, using samples from individuals naturally exposed to malaria infection.

Risk assessment and source identification of heavy metal contamination by multivariate and hazard index analyses of a pipeline vandalised area in Lagos State, Nigeria.

Petroleum contamination is a significant contributor of elevated level of toxic heavy metals, which are of great concern to human health, due to their non-biodegradable nature. Agaye community has experienced frequent gasoline spills due to pipeline vandalisation, resulting in the contamination of soil and water sources. The concentrations of metals (Cd, Cr, Cu, Mn, Ni, Pb, V and Zn) in groundwater, surface-water and soil were determined from a total of 216 samples acquired bi-monthly for two years by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) to evaluate the impact of oil spills. Multivariate analyses using principal component analysis (PCA) and cluster analysis (CA) were also used to study the interactions between metals and identify the possible sources of contamination. The concentrations of heavy metals in soil and water samples (surface and groundwater) were in decreasing order of Mn > Ni > Zn > Cu > V > Cr > Pb > Cd and Ni > Zn > V > Cu > Mn > Pb > Cr > Cd respectively. Ni concentration ranged from 0.42-8.05 mg kg-1 and 0.10-2.85 mg L-1 for soil and groundwater respectively. Ni and V were more enhanced (P < 0.05) in soil samples. This study showed that there was significant relationship between elevated levels of Cr, Cu, Ni and Zn and oil spillage, due to petroleum spills and that residents were vulnerable to and at greater risk of non-carcinogenic hazards if they consumed groundwater. Multivariate analyses showed significant anthropogenic intrusions of two diagnostic heavy metals (Ni and V) for petroleum contamination in the soils and water sources.

Inhibitory Activities of Ethanolic Extracts of Two Macrofungi Against Eggs and Miracidia of Fasciola Spp.

Fascioliasis is a disease of livestock which is now recognized as an emerging disease in humans. Cantharellus cibarius and Ganoderma applanatum are known for their medicinal properties. The use of ethanolic extracts of these macrofungi against the eggs and miracidia of Fasciola spp. is a promising method to break the parasite transmission cycle. The aim of the study is to evaluate the inhibitory effects of ethanolic extracts of the mushrooms on eggs and miracidia of Fasciola spp. Concentrated eggs and miracidia of Fasciola spp. were exposed to different concentrations (1-8 mg/ml) of extracts of Ganoderma applanatum (GEE) and Cantharellus cibarius (CEE) at different time intervals. GEE showed superior antiparasitic activities when compared to CEE at all concentrations tested. Significant positive correlations were observed between the concentration of GEE and mortality in miracidia (r=0.980, P <0.05) and CEE and mortality in miracidia (r= 0.968, P <0.05). The study showed that ethanolic extracts of G. applanatum and C. cibarius have ovicidal and miracicidal activities. While G. applanatum showed excellent activities, activities in C. cibarius were moderate. Therefore, these mushroom extracts can be regarded as promising sources of bioactive compounds that could be developed into ovicides and miracicides.

Molluscicidal activities of curcumin-nisin polylactic acid nanoparticle on Biomphalaria pfeifferi.

BACKGROUND: Snail intermediate host control is a widely canvassed strategy for schistosomiasis control in endemic countries. While there have been increasing studies on the search for potent molluscicides in the past years, the use of nanoparticulate agents as molluscicides is yet to gain wide attention. The aim of this study was to assess the molluscicidal potential of curcumin-nisin poly lactic acid (PLA) entrapped nanoparticle (CurNisNp) against Biomphalaria pfeifferi, a snail intermediate host for Schistosoma mansoni. METHODOLOGY/PRINCIPAL FINDINGS: CurNisNp formulated by double emulsion method was tested against the young adults, < 1 week, 1-2-week old juveniles, 1 day (blastula) and 7 day-old (hippo-stage) egg masses of B. pfeifferi. Mortality in the different stages was determined after 96-h of exposure at varying concentrations (350, 175, 87.5, 43.75 and 21.88 ppm). The sub-lethal effects of CurNisNp on the hatchability of the 7-day-old egg masses and egg laying capacity of the young adult snails were determined. The CurNisNp diameter, polydispersity index (PDI), zeta potential and drug entrapment efficiency were 284.0 ± 17.9 nm, 0.166 ± 0.03, -16.6 ± 2.45 mV and 35.0% respectively. The < 1 week old juveniles and the 1-day-old egg stage (blastula) of B. pfeifferi with LC50 277.9 ppm and 4279.5 ppm were the most susceptible and resistant stages to the drug respectively. CurNisNp was also observed to cause significant reductions (P<0.05) in egg hatchability and egg laying capacity with strong negative correlation between egg laying capacity and concentration (r = -0.928; P<0.05). CONCLUSION/SIGNIFICANCE: This study showed that CurNisNp has molluscicidal activities on different developmental stages of B. pfeifferi. It is therefore recommended that the formulation be more optimised to give a nanoparticle with a narrow range monodispersed PDI for better drug distribution and eventual greater molluscicidal activities.

Interactions between gastrointestinal parasitism and pneumonia in Nigerian goats.

This study was carried out to determine the burden and interactions between parasitism and pneumonia in Nigerian goats. A total of 430 goats were examined for gastrointestinal (GIT) parasites by faecal analysis using sedimentation by gravity, Modified Winconsin sugar floatation method, McMaster egg counting techniques and for lung consolidation, pathology and morphometry of pneumonia were evaluated by standard techniques. The results from the faecal examination revealed the presence of nine (9) gastrointestinal parasites namely Eimeria, Trichuris, Oesophagostomum, Strongyloides, Moniezia, Haemonchus, Bunostomum, Trichostrongylus, and Nematodirus species and at an overall high prevalence of 74%. Eimeria species was found to have the highest prevalence of 26% for single infection, while co-infection of Eimeria and Trichuris species 21% was highest amongst other parasites, and of the breeds of goats examined for GIT parasites, the Red Sokoto (RS) breed had the highest infection rate 37%. The results from the lungs analysis showed 59% prevalence with the highest consolidation in RS (48.2%), followed by WAD (34.2%). The age of the goats was key in the infection rate of both parasites and pneumonia, which was seen to be highest in younger goats, with a significant (2.10 ± 0.4 × 103) GI parasite burden in >1-2 years group. The prevalence of GIT infection with lung consolidation in the goats, was observed to influence their Body condition scores (BCS) (p < 0.05). This study showed that body condition score, age and breed of goats may be predisposing factors to gastrointestinal parasites and pneumonia in Nigerian goats. There was a strong correlation (+0.243, p = 0.00) of occurrence of gastrointestinal parasitism and pneumonia in this study. Possibility of combined prophylactic measures should be considered in the nearest future.

Antiplasmodial Activity and Toxicological Assessment of Curcumin PLGA-Encapsulated Nanoparticles.

Curcumin is a polyphenolic pigment isolated from the rhizomes of Curcuma longa (turmeric), a medicinal plant widely used in the ancient Indian and Chinese medicine. The antiplasmodial activity of curcumin is often hampered by its fast metabolism and poor water solubility, thus its incorporation into a delivery system could circumvent this problem. This study aimed to evaluate the in vivo antiplasmodial activity and the toxicity assessment of curcumin incorporated into poly (lactic-co-glycolic) acid (PLGA) nanoparticles. Curcumin was loaded with poly (D,L-lactic-co-glycolic acid) (PLGA) using solvent evaporation from oil-in-water single emulsion method. The nanoparticles were characterized and evaluated in vivo for antimalarial activities using Peter's 4-day suppressive protocol in mice model. Hematological and hepatic toxicity assays were performed on whole blood and plasma, respectively. In vivo anti-parasitic test and toxicity assays for free and encapsulated drug were performed at 5 and 10 mg/kg. In vitro cytotoxicity of free and PLGA encapsulated curcumin (Cur-PLGA) to RAW 264.7 cell line was also determined at varying concentrations (1000-7.8 µg/mL). The size and entrapment efficiency of the nanoparticulate drug formulated was 291.2 ± 82.1 nm and 21.8 ± 0.4 respectively. The percentage parasite suppression (56.8%) at 5 mg/kg was significantly higher than in free drug (40.5%) of similar concentration (p < 0.05) but not at 10 mg/kg (49.5%) at 4-day post-treatment. There were no significant differences in most of the recorded blood parameters in free curcumin and PLGA encapsulated nanoparticulate form (p > 0.05) except in lymphocytes which were significantly higher in Cur-PLGA compared to the free drug (p < 0.05). There were no significant differences in hepatotoxic biomarkers; aspartate aminotransferase and alanine aminotransferase concentrations in various treatment groups (p > 0.05). At higher concentrations (1000 and 500 µg/mL), Cur-PLGA entrapped nanoparticle showed higher toxicity compared with the free drug (p < 0.05) in exposed RAW 264.7 cell line. The cell viability was, however, higher in Cur-PLGA nanoparticles than in free curcumin at lower concentrations (p > 0.05). The antiplasmodial activity and safety of Cur-PLGA was better at lower concentration.

Acquisition, maintenance and adaptation of invasion inhibitory antibodies against Plasmodium falciparum invasion ligands involved in immune evasion.

Erythrocyte-binding antigens (EBAs) and P. falciparum reticulocyte-binding homologue proteins (PfRhs) are two important protein families that can vary in expression and utilization by P. falciparum to evade inhibitory antibodies. We evaluated antibodies at repeated time-points among individuals living in an endemic region in Nigeria over almost one year against these vaccine candidates. Antibody levels against EBA140, EBA175, EBA181, PfRh2, PfRh4, and MSP2, were measured by ELISA. We also used parasites with disrupted EBA140, EBA175 and EBA181 genes to show that all these were targets of invasion inhibitory antibodies. However, antigenic targets of inhibitory antibodies were not stable and changed substantially over time in most individuals, independent of age. Antibodies levels measured by ELISA also varied within and between individuals over time and the antibodies against EBA181, PfRh2 and MSP2 declined more rapidly in younger individuals (≤15 years) compared with older (>15). The breadth of high antibody responses over time was more influenced by age than by the frequency of infection. High antibody levels were associated with a more stable invasion inhibitory response, which could indicate that during the long process of formation of immunity, many changes not only in levels but also in functional responses are needed. This is an important finding in understanding natural immunity against malaria, which is essential for making an efficacious vaccine.

Anti-Schistosoma IgG responses in Schistosoma haematobium single and concomitant infection with malaria parasites.

Areas prone to schistosomiasis are also at risk of malaria transmission. The interaction between the causal agents of the two diseases could modulate immune responses tailored toward protecting or aggravating morbidity dynamics and impair Schistosoma diagnostic precision. This study aimed at assessing the effect of Plasmodium spp. in concomitant infection with Schistosoma haematobium in modulation of anti-Schistosoma IgG antibodies. The school-based cross-sectional study recruited a total of 322 children screened for S. haematobium and Plasmodium spp. Levels of IgG against S. haematobium-soluble egg antigen (SEA) in single S. haematobium/malaria parasites infection and co-infection of the two parasites in schoolchildren were determined. Data were analyzed using χ(2), Fisher's exact test, and Tukey's multiple comparison test analyses. The prevalence of single infection by S. haematobium, Plasmodium spp., and concurrent infection due to the two pathogens was 27.7, 41.0, and 9.3%, respectively (p < 0.0001). Anti-Schistosoma IgG production during co-infection of the two pathogens (1.950 ± 0.742 AU) was significantly higher than the value recorded for single malaria parasites' infection (1.402 ± 0.670 AU) (p < 0.01) but not in S. haematobium infection (1.591 ± 0.604 AU) (p > 0.05). The anti-Schistosoma IgG production in co-infection status was however dependent on the intensity of Plasmodium spp. with individuals having high intensity of malaria parasites recording lower anti-Schistosoma IgG. This study has implication for diagnosis of schistosomiasis where anti-Schistosoma IgG is used as an indicator of infection. Efforts should be made to control the two infections simultaneously in order not to undermine the efforts targeted toward the control of one.

Renal related disorders in concomitant Schistosoma haematobium-Plasmodium falciparum infection among children in a rural community of Nigeria.

Schistosomiasis and malaria are two common parasitic diseases that are co-endemic in resource-poor communities of sub-Saharan Africa. This study aims to assess the effects of single and concomitant Plasmodium falciparum and Schistosoma haematobium infections on two indicators of renal injury in school children in a rural community of Nigeria. A cross-sectional epidemiological survey was carried out on a total of 173 schoolchildren between ages 6 and 18 years (mean age 11.4±2.6 years). Urine and blood samples were collected by standard methods for concurrent microscopic diagnosis of S. haematobium and P. falciparum infections. Urinary blood (hematuria) and protein were determined using a urinalysis dipstick. The prevalence of single infections was 75.1% and 78.2% for S. haematobium and P. falciparum, respectively. A total of 57.1% individuals were infected with the two parasites. The prevalence of hematuria was significantly higher in the co-infection status (63.8%) than in single S. haematobium (52.2%) and P. falciparum (43.7%) infection statuses (p=0.04), while no significant variation was recorded in proteinuria in the three infection statuses (p=0.53). The proportion of children with renal injury associated with the co-infection of these parasites is very high, particularly in young children, who seem to have a higher prevalence of hematuria.