Abstract. The aim of the present study was to assess the frequency of intestinal parasitic infection among patients with gastrointestinal tract disorders from the Greater Cairo region, Egypt. In addition, a comparison was made of the accuracy of direct thin and thick smear, formol-ether sedimentation (FEC), centrifugal flotation (CF), and mini-FLOTAC techniques in the diagnosis of infection. Out of 100 patients, the overall prevalence of parasitic infection was 51%. Only 6% had dual infection. Giardia lamblia was the most common parasite (26%), followed by Hymenolepis nana (20%), Entamoeba coli (8%), and Enterobius vermicularis (3%). Except the statistically significant association between E. vermicularis infection and perianal itching and insomnia (P < 0.001), age, gender, and complaints of the examined individuals had no association with prevalence of parasitic infection. Both FEC and CF were equally the most accurate techniques (accuracy = 98.2%, confidence interval [CI] = 0.95-1.0, and κ index = 0.962), whereas the Kato-Katz method was the least accurate (accuracy = 67.5%, CI = 0.57-0.78, and κ index = 0.333). However, mini-FLOTAC-ZnSO 4 was the most accurate for diagnosis of helminthic infection, and FEC was more accurate for diagnosis of protozoal infection (accuracy = 100%, CI = 1.0-1.0, and κ index = 1).

N-89, a new antimalarial endoperoxide, was selected as a promising antimalarial compound showing high activity and selectivity. To study the mechanism of N-89 action, N-89 resistant strain (NRC10) was obtained by intermittent drug pressure. NRC10 had a tenfold increase in the EC(50) value of N-89. No cross-resistance was obtained with other antimalarial compounds. Comparative proteome analysis of N-89 sensitive and NRC10 strains revealed over-expression of 12 spots and down-regulation of 14 spots in NRC10. Fifteen proteins were identified of Plasmodium falciparum origin. The identified proteins representing several functions, mainly related to the glycolytic pathway, and metabolism of protein and lipid. Our results suggest that identified proteins may be candidates of antimalarial endoperoxide targets.

Preventive chemotherapy with praziquantel is the mainstay of schistosomiasis control. However, drug resistance is an imminent threat, particularly with large-scale administration of praziquantel, in addition to much less efficacy against young schistosomes. Several biological activities of limonin have been explored such as insecticidal, insect antifeedant, and growth-regulating activity on insects as well as antimalarial, antiviral, anticancer, cholesterol-lowering, and antioxidant activities. This study investigates limonin as an alternative antischistosomal compound using two novel, single, oral dose regimens. In the current work, the therapeutic efficacy of different limonin dosing protocols was evaluated in experimentally infected mice harboring Schistosoma mansoni (Egyptian strain) juvenile or adult stages. Oral administration of limonin in a single dose of 50 or 100 mg/kg on day 21 post-infection (p.i.) resulted in a significant worm burden reduction of 70.0 and 83.33 %, respectively. The same dose given on day 56 p.i. reduced total worm burdens by 41.09 and 60.27 %, respectively. In addition, significant reductions of 34.90 and 47.16 % in the hepatic and 46.67 and 56.1 % in the intestinal tissue egg loads, respectively, associated with significant alterations in the oogram pattern with elevated dead egg levels. Limonin produced ameliorations of hepatic pathology with reduction in dimensions and number of granulomas. Limonin also produced a variety of tegumental alterations in treated worms including tubercular disruption, edema, blebbing, and ulcerations. Results obtained by this work elucidated promising limonin bioactivity against S. mansoni juvenile and adult stages and provided a basis for subsequent experimental and clinical trials.

Background: Continuous attempts are being made to develop new and more effective drugs for treatment of schistosomiasis. Curcuma longa is a medicinal plant that contains yellow pigments known as curcuminoids (curcumin, bidesmetoxi-curcumin and monodesmetoxi-curcumin), with curcumin as the highest component. The main biological effect depends on curcumin content. Curcumin has low bioavailability and poor-water solubility. Preparation of C. longa (Cl) nanoemulsion was attempted to enhance solubility and bioavailability of curcumin. Objective: The production of Cl nanoemulsion, and study of its pharmacokinetic properties (namely solubility and intestinal bioavailability) and anti-helminthic effects on Schistosoma mansoni cercariae, schistosomules and adults. Methodology: Cl nanoemulsion was prepared from ethanol extract of crude powder of Cl rhizome. Characterization was done by transmission electron microscope (TEM), testing solubility and intestinal bioavailability. Schistosomicidal effects were performed by in vitro assay. Results: Cl nanoemulsion showed increased solubility and bioavailability compared to ethanol extract of the tested plant; as well as time and dose dependent schistosomicidal effects on cercariae and 24h-old schistosomules of S. mansoni. In addition, it exhibited an optimal activity against the adult stage with decreased motor activity of the worms. Conclusion: This study proves that Cl nanoemulsion has enhanced solubility and bioavailability, as well as schistosomicidal activity.

There is renewed interest in natural products as a starting point for discovery of drugs for schistosomiasis. Recent studies have shown that phytol reveals interesting in vivo and in vitro antischistosomal properties against Schistosoma mansoni adult worms. Here, we report the in vitro antischistosomal activity of phytol against Schistosoma haematobium juvenile and adult worms and alterations on the tegumental surface of the worms by means of scanning electron microscopy. The assay, which was carried out with 6 concentrations (25, 50, 75, 100, 125, and 150 μg/ml) of phytol, has shown a promising activity in a dose and time-dependent manner. There was a significant decline in the motility of the worms and a mortality rate of 100% was found at 48 hr after they had been exposed to phytol in the concentration of 150 μg/ml. Male worms were more susceptible. On the ultrastructural level, phytol also induced tegumental peeling, disintegration of tubercles and spines in addition to morphological disfiguring of the oral and ventral suckers. This report provides the first evidence that phytol is able to kill S. haematobium of different ages, and emphasizes that it is a promising natural product that could be used for development of a new schistosomicidal agent.