Fluconazole as Schistosoma mansoni cytochrome P450 inhibitor: In vivo murine experimental study.

Schistosomiasis is a chronic disease caused by blood flukes of the Schistosoma spp. New approaches against this morbid infection are needed. In this study, we investigated fluconazole (FLZ) as an inhibitor of Schistosoma mansoni cytochrome P450 (S. mansoni CYP450) enzyme at different life cycle stages. We compared FLZ (10 mg/kg for two days) effects when administrated early 5 days post-infection (dpi) (Early I) and 21 dpi (Early II) versus late administration 60 dpi on S. mansoni CYP450 gene expression. These different FLZ treatment regimens were evaluated in experimentally infected mice with S. mansoni. This study showed that administration of FLZ, whether early or late during schistosomal infection, resulted in significant inhibition of S. mansoni CYP450 expression in the adult stage (P < 0.001). Early exposure to FLZ during the first week of infection significantly decreased the number of schistosomula that reached the adult stage compared to the infected control group and resulted in significant inhibition of S. mansoni CYP450 expression (P < 0.001) in the adult stage. In the Early I group, the fewest number of eggs per liver tissue gram was recorded. Our data suggested that FLZ is a S. mansoni CYP450 gene expression inhibitor with greater effect on schistosomula stages.

Activity of isoflavone biochanin A in chronic experimental toxoplasmosis: impact on inflammation.

Toxoplasma gondii is a worldwide prevalent parasite. The infection has been linked to variable inflammatory effects including neuroinflammation. Biochanin A (BCA) is an isoflavone, known for its anti-inflammatory and anti-oxidative properties. In this study, we examined the effect of BCA on the brain and liver inflammatory lesions in a murine model with chronic toxoplasmosis. Mice were divided in to six groups: non-infected control, non-infected BCA-treated, and four infected groups with Toxoplasma gondii Me49-type II cystogenic strain: infected control, BCA (50 mg/kg/day)-treated, combined BCA/cotrimoxazole-treated and cotrimoxazole (370 mg/kg/day) alone-treated. Gene expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and inducible nitric oxide synthase (iNOS) was evaluated by quantitative real-time PCR in the brain and liver tissues. In the infected control group, an upregulation of TNF-α and IL-1ß mRNA expression levels was found. However, a downregulation of iNOS expression was detected in the brain of infected control mice. In both BCA- and combined-treated groups, the brain and liver tissues showed significantly reduced inflammatory lesions compared to the infected control mice with inhibited TNF-α and IL-1ß mRNA levels. The iNOS expression levels in the brain tissues of BCA group were significantly higher than the levels of the infected control group. BCA alone or combined significantly reduced T. gondii cyst count in the brain tissues. In conclusion, the anti-inflammatory activity of BCA was demonstrated in the brain tissues of mice with chronic toxoplasmosis with decreased TNF-α and IL-1ß expression levels and increased iNOS expression levels.

Association Between Giardia Genotype and Oxidative Stress Biomarkers Among Giardia-Infected Children: A Case-Control Study.

PURPOSE: Giardia duodenalis is the most common worldwide intestinal protozoal infection. The implication of free radicals in organ injury occurs through oxidative stress. Infections as Giardia may act as a triggering or promoting factor for oxidative stress, particularly in children with compromised immunity. Besides, the effect of Giardia genotype on oxidative stress status is yet to be explored. Therefore, we sought to compare the oxidative stress status between Giardia positive cases (case group) and Giardia negative cases (control group), and to explore the association between Giardia genotype and the level of oxidative stress markers in Giardia-infected children, especially those receiving immunosuppressive therapy. METHODS: Pediatric patients attending Mansoura University Children Hospital in the period from April 2015 to October 2016 were enrolled. Both case (n = 50) and control (n = 50) groups were further subdivided into immunosuppressive therapy recipients (ITR) and non-immunosuppressive therapy recipients (NITR). Genotyping of Giardia from positive stool samples by PCR was carried out, and oxidative stress markers were measured from venous blood samples. RESULTS: Giardia positive cases had higher levels of Malondialdehyde (MDA) and lower levels of total antioxidant capacity (TAC). MDA highest level was associated with mixed genotypes A and B, while the highest TAC level was associated with Giardia genotype A in both ITR and NITR cases. CONCLUSION: Elevated oxidative stress biomarkers in pediatric patients infected with specific Giardia genotypes should receive considerable attention, because if prompt treatment is not conducted, oxidative damage may occur in patients with giardiasis, especially those receiving immunosuppressive therapy.

Non-lethal rodent malarial infection prevents collagen-induced arthritis in mice via anti-arthritic immunomodulation.

AIMS: Immunomodulatory effects of parasitic infections on the outcomes of allergic or autoimmune disorders have been addressed in many experimental studies. We examined the effects of Plasmodium yoelii 17X NL (Py) infection on collagen-induced arthritis (CIA). METHODS AND RESULTS: Male DBA/1J mice were immunized with bovine type II collagen (IIC). Py inoculation was induced at three different time points (1, 4 weeks after or 4 weeks before the immunization). Only the inoculation at 4 weeks after IIC immunization significantly inhibited arthritis development. Non-malarial anaemia induced by phenylhydrazine hydrochloride (PHZ) did not affect arthritis development. In the infected mice, anti-IIC IgG levels were transiently reduced. In addition, splenic production of pro-arthritic cytokines (IL-17 and TNF-α) and IFN-γ decreased, whereas IL-10 production increased. Flow cytometric analysis clarified that the main IL-10 producers in Py-infected mice had the CD4+ CD25- Foxp3- phenotype, presumably Tr1 cells. CONCLUSION: We demonstrated that experimental malarial infection alleviated autoimmune arthritis via immunomodulation, suggesting the importance of malaria in the hygiene hypothesis and the significance of searching for therapeutic immunomodulatory molecules from malarial parasites.

Histopathological and ultrastructural assessment of atovaquone-proguanil hydrochloride combination in chronic murine toxoplasmosis.

Over one billion people worldwide are expected to have Toxoplasma gondii infection with anonymous health problems. Available therapies are ineffective for persistent chronic toxoplasmosis. So, there is an imperative need for effective therapies to eliminate chronic tissue stage. In this study, we aimed to assess the effect of a drug combination of atovaquone and proguanil hydrochloride in the treatment of experimental chronic toxoplasmosis. Fifty Swiss Webster mice were used in the study. Forty mice were infected with Me49 type II cystogenic Toxoplasma gondii strain and allocated into four groups: infected untreated (vehicle-administered), infected and treated with cotrimoxazole (CTX) 370 mg/kg/day, infected and treated with atovaquone (ATV) 100 mg/kg/day, and infected and treated with atovaquone/proguanil (ATV/PROG) 50 mg/kg/day. An additional group of uninfected mice was used as an uninfected control group. Drug treatment was initiated 8 weeks post-infection and continued for two weeks. All mice were sacrificed 12 weeks post-infection. Parasitological and histopathological parameters were assessed. Toxoplasma gondii cysts recovered from brain tissue homogenates of both infected untreated and ATV/PROG-treated groups were examined by scanning electron microscopy. Combined ATV/PROG treatment demonstrated a significant reduction of Toxoplasma gondii cyst count in brain tissue (a reduction rate of 84.87%) compared to untreated group (P < .001). Brain tissues obtained from ATV/PROG treated group showed reduction of inflammatory infiltrate and marked attenuation and deformation of recovered Toxoplasma gondii cysts. We conclude that ATV/PROG drug combination could offer a potential drug therapy for Toxoplasma gondii chronic cystic stage.

Immunological, histopathological, and ultrastructural evidence of steroid-induced reactivation of chronic murine toxoplasmosis.

We developed a model of steroid-induced reactivation of chronic murine toxoplasmosis to mirror similar effects of steroids or other immunosuppressants in infected humans. Immunological, histopathological, and ultrastructural parameters were reported. Prior to steroid administration, mice were infected with 10 cysts of the Me49 strain of Toxoplasma gondii. Mice were treated with dexamethasone (DXM, 2.5 mg/kg/day in drinking water), alone or combined with Solu-Cortef (SOLU, 50 mg/kg by subcutaneous injection 3 times a week) for 7 weeks or left untreated as control. Histopathological changes and ultrastructural effects of steroids on the course of chronic toxoplasmosis were recorded. By electron microscopy, the brains of infected combined treated mice showed an increase in number of tachyzoites and bradyzoites, degeneration, and necrosis of neural cells and hydropic degeneration besides the observed rupture of toxoplasma cysts releasing free tachyzoites in brain tissue. DXM+SOLU-combined treatment also significantly increased mortality, mean brain cyst count as compared to infected untreated mice (P = .01 and). Moreover, 3/12 (25%) treated animals developed clinical signs of toxoplasmic encephalitis. This simple model of drug-induced reactivation of chronic toxoplasmosis permits investigation of host-parasite interaction and may be used for the evaluation of chemotherapeutics in immunocompromised infected patients.

Insulin growth factor inhibitor as a potential new anti-schistosoma drug: An in vivo experimental study.

BACKGROUND AND OBJECTIVE: Tyrphostin "AG1024" is an insulin growth factor-1 receptor (IGF-1R) inhibitor that displayed an effect on the viability of larval and mature schistosomes in vitro. We sought to investigate the possible in vivo role of AG1024 as a potential new anti-Schistosoma drug against immature and adult stages of Schistosoma mansoni and its effect on the degree of hepatic fibrosis and insulin pathway. METHODS: The study included a control non-infected group and 5 groups of S. manosoni-infected CD-1 albino mice (20 mice each) assigned to treatment as follows: vehicle-treated, early AG1024, 30µg/100µl DMSO, IP for 10days started 30days post-infection (dpi), early praziquantel (PZQ), 500mg/kg orally for 2days (30dpi), late AG1024 (60dpi), and late PZQ (60dpi). All mice were sacrificed 12 weeks post-infection. Parasitological, chemical and histopathological parameters were studied. Immunohistochemistry of TGF-ß and GLUT4 in liver sections was done to further evaluate the effect of AG1024 on the degree of hepatic fibrosis and insulin signaling pathway, respectively. RESULTS: Early administration of AG1024 (30dpi) resulted in significant reduction of hepatic and intestinal tissue egg count with a reduction of 79.99% and 89.1% respectively. Late administration of AG1024 (60dpi) led to 77.78% reduction of intestinal eggs count; however, hepatic egg count wasn't reduced significantly. No reduction in worm burden was recorded for both administration regimens. Both regimens lead to significant decrease of both ALT and AST, mean hepatic granuloma diameter but an increase in fibrosis percentage (65.2% and 55% respectively). Both early and late treatment with AG1024 showed a significant increment of TGF-ß expression by 71.4% and 39.3%, respectively (p<0.0001) compared to PZQ-treated and infected non-treated groups. Hepatic GLUT4 expression was significantly decreased compared to infected non-treated group (p<0.001) and the corresponding PZQ-treated group. CONCLUSION: Early AG1024 administration induced more significant results compared to early PZQ with a promising activity against egg production and subsequent reduction of tissue egg load rather than direct schistosomicidal effect; however, it induced granuloma fibrosis, TGF-ß expression, and disrupted the insulin signaling pathway.

Possible antifibrotic effect of GDC-0449 (Vismodegib), a hedgehog-pathway inhibitor, in mice model of Schistosoma-induced liver fibrosis.

Liver fibrosis is a pathological process complicating schistosomiasis. It is an active process of continuous extracellular matrix accumulation. In Egypt, schistosomiasis re-infection is a continuing problem especially in rural areas. In this study we examined the antifibrotic effect of GDC-0449 (Vismodegib), a hedgehog-pathway inhibitor as a new molecular target for Schistosoma-induced liver fibrosis, in addition to exploring its effect as antischistosomal drug. The effect of GDC-0449 alone or combined with Praziquantel was tried experimentally in infected mice with Schistosoma mansoni. Fifty CD-1 Swiss female albino mice were used, forty mice were infected with Schistosoma mansoni cercariae. Animals were grouped into five groups; uninfected control, infected untreated, infected treated with Praziquantel (500mg/kg/day) for two days, infected treated with GDC-0449 (40mg/kg/day) for seven days, and infected treated with combined Praziquantel and GDC-0449. Parasitological and chemical parameters, hydroxyproline level and liver granuloma were assessed. Liver fibrosis was reduced significantly evidenced by reduced hydroxyproline levels [P<0.01 for combined (Praziquantel/GDC-0449) treatment groups, P<0.001 for GDC-0449-treated group]. Also, histopathological examination of liver tissues revealed that the mean diameter of granulomas was statistically reduced (P=0.001) with a reduction rate of 24.4% on treatment with GDC-0449. In GDC-0449/Praziquantel combined treatment group, number and mean diameter of the granulomas were reduced significantly P<0.001, and P=0.001 respectively. No antischistosomal effect was recorded for GDC-0449 in this study.