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 anti-malarial 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 mg/kg 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 were 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 (P0.05) except in lymphocytes which were significantly higher in Cur-PLGA compared to the free drug (P0.05). At higher concentrations (1000 and 500 µg/mL), Cur-PLGA entrapped nanoparticle showed higher toxicity compared with the free drug (P0.05). The antiplasmodial activity and safety of Cur-PLGA was better at lower concentration.

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. 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). 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. Elimination of snail intermediate host of schistosomiasis has been widely advocated as an arm of integrated control for schistosomiasis. This becomes important as reports now abound on development of praziquantel resistance in schistosomes. Nanotechnology has been applied in control of tropical diseases including schistosomiasis. The few available nanomedicines were targeted against the Schistosoma worms without research efforts on the use of the same technology against the molluscan host of the parasite. This study seeks to assess the molluscicidal potential of CurNisNp on Biomphalaria pfeifferi; a snail intermediate host of Schistosoma mansoni. The formulation was tested on the different developmental stages of the snail. The formulation showed decreasing molluscicidal activity with increase in age of the snail. Impairment of the egg laying capacity of the adult snails was related to nanoparticle concentration. The egg was the most resistant stage. It is evident from the study that the formulated nanoparticle had molluscicidal properties and to further harness this potential, optimisation of the formulation to give a narrow range monodispersed polydispersity index for better drug distribution is recommended.

A cross-sectional study on urogenital schistosomiasis in children; haematuria and proteinuria as diagnostic indicators in an endemic rural area of Nigeria

A survey of prevalence and intensity of gastro-intestinal parasites of carnivores in three university zoological gardens in South-West Nigeria was conducted. Faecal samples collected were analysed with flotation technique using a saturated solution of zinc sulfate as the floating solution, McMaster Egg Counting Technique and Petri Dish-Filter Paper Slant technique for larval recovery. Faecal examination revealed an overall infection prevalence of 49.1%. The prevalence in University of Ibadan (UI) zoo was 23.7%, 54.8% in Obafemi Awolowo University (OAU) and 69.2% in University of Ilorin (UniIlorin) zoos. The gastrointestinal helminths identified include Ancylostoma sp., Ascaris sp., Baylisascaris sp., Toxascaris sp., Toxocara sp., Strongyloides sp. and Entamoeba sp. was the only protozoa encountered. Ascaris sp., had the highest prevalence of 22.6%, followed by Ancylostoma sp. with a rate of 20.8%. Baylisascaris sp., and Strongyloides sp. both had a prevalence rate of 13.2% each, while Entamoeba sp. yielded the lowest prevalence (3.8%). Regular monitoring of parasitic diseases and the use of selective treatments would be effective for the control of the gastrointestinal helminths for the wellbeing of animals, safety of zoo keepers and tourists in the zoo. Key words: Carnivores, gastrointestinal parasites, zoological gardens, South-West Nigeria.