Schistosoma mansoni: N-acetylcysteine downregulates oxidative stress and enhances the antischistosomal activity of artemether in mice

Artemether (Art), a derivative of the antimalarial artemisinin, also exhibit antischistosomal properties. N-acetylcysteine (NAC) has a diversity of applications, largely because of the chemical properties of the thiol moiety present in its structure. The ability of this moiety to sweep reactive oxygen species is well-established with NAC. This study investigates the ability of NAC to enhance the therapeutic potential of Art against adult Schistosoma mansoni infection and evaluates the protective role of this antioxidant on S. mansoni-induced oxidative stress. Mice were divided into five groups; normal (i), infected control (ii), infected treated with NAC, 300 mg/kg 5 days a week/4weeks (iii), infected treated with Art (300 mg/kg) 7 weeks post infection (iv) and infected treated with both NAC and Art (v). Results showed that Art produced a significant reduction in total number of worms when used alone. Also, it decreased hepatic ova count significantly accompanied with an increase in the percentage of dead ova. Treatment with NAC alone increased the percentage of dead ova; meanwhile, it enhanced the decrease in total number of worms and hepatic ova count when used with Art. Infection with S. mansoni significantly increased tissue GSH, GR, SOD and serum ALT and GGT, while decreased the activities of GST, GPx and the levels of proteins and albumin compared to normal control. Treatment with NAC alone approximately recovered the contents of GSH, activities of GPx and levels of serum albumin, ALT and GGT relative to normal control. A tendency for normalization in activities of the antioxidant enzymes mentioned above and serum levels of liver function tests was observed in the groups treated with Art alone or Art + NAC. Conclusion: NAC downregulates oxidative stress induced by S. mansoni infection and enhances the therapeutic potential of artemether against adult schistosomes.     

Miltefosine, a promising novel agent for schistosomiasis mansoni

This research aims towards developing an alternative antischistosomal drug using miltefosine, which is primarily used in the treatment of leishmaniasis. The treatment and control of schistosomiasis, a notable neglected tropical disease (NTD), rely on a single drug, praziquantel (PZQ). The dependency on PZQ exclusively is quite alarming, given the spread of the disease (over 200 million people infected and close to 800 million people at risk in three continents) and the threat of drug resistance. This study shows that the oral administration of miltefosine in a daily dose of 20 mg/kg for five successive days to mice infected with either invasive, juvenile or adult stages of Schistosoma mansoni resulted in significant reduction of worm burden, hepatic granulomata size and amelioration of hepatic pathology. Scanning Electron Microscopy revealed that miltefosine induced severe tegumental damage in adult schistosomes. In conclusion, we believe this is the first study highlighting miltefosine as a promising novel agent for schistosomiasis mansoni.     

Effect of Ketoconazole,a Cytochrome P450 Inhibitor,on the Efficacy of Quinine and Halofantrine against Schistosoma mansoni in Mice

The fear that schistosomes will become resistant to praziquantel (PZQ) motivates the search for alternatives to treat schistosomiasis. The antimalarials quinine (QN) and halofantrine (HF) possess moderate antischistosomal properties. The major metabolic pathway of QN and HF is through cytochrome P450 (CYP) 3A4. Accordingly, this study investigates the effects of CYP3A4 inhibitor, ketoconazole (KTZ), on the antischistosomal potential of these quinolines against Schistosoma mansoni infection by evaluating parasitological, histopathological, and biochemical parameters. Mice were classified into 7 groups: uninfected untreated (I), infected untreated (II), infected treated orally with PZQ (1,000 mg/kg) (III), QN (400 mg/kg) (IV), KTZ (10 mg/kg)+QN as group IV (V), HF (400 mg/kg) (VI), and KTZ (as group V)+HF (as group VI) (VII). KTZ plus QN or HF produced more inhibition (P<0.05) in hepatic CYP450 (85.7% and 83.8%) and CYT b5 (75.5% and 73.5%) activities, respectively, than in groups treated with QN or HF alone. This was accompanied with more reduction in female (89.0% and 79.3%), total worms (81.4% and 70.3%), and eggs burden (hepatic; 83.8%, 66.0% and intestinal; 68%, 64.5%), respectively, and encountering the granulomatous reaction to parasite eggs trapped in the liver. QN and HF significantly (P<0.05) elevated malondialdehyde levels when used alone or with KTZ. Meanwhile, KTZ plus QN or HF restored serum levels of ALT, albumin, and reduced hepatic glutathione (KTZ+HF) to their control values. KTZ enhanced the therapeutic antischistosomal potential of QN and HF over each drug alone. Moreover, the effect of KTZ+QN was more evident than KTZ+HF.     

Comparative efficacy and bioavailability of different praziquantel brands

This study investigates the efficacy, bioavailability and drug metabolizing enzymes mainly involved in the metabolism of the commercial brands of praziquantel (PZQ) in Egypt in comparison with the original pure powder. Mice infected with PZQ-susceptible (CD) or PZQ-insusceptible (EE2) Schistosoma mansoni isolates were divided each into seven groups, six of them received PZQ brands (Distocide, Epiquantel, Biltricide, Bilharzid, Praziquantel, and pure PZQ), while the seventh one was left as infected untreated. Seven weeks post-infection, worms were quantified and hepatic CYP450 and CYT b5 were examined. For PZQ pharmacokinetics, groups of normal mice were given the different PZQ brands and divided into subgroups, killed at 2, 5, 15, 30, 60, 90, 120,150, 180, 240 and 360 min post-dosing. Physicochemical examination revealed better dissolution rates for Biltricide, Distocide and PZQ T3A rather than Epiquantel and Bilharzid. Significant decrease in worm burden was recorded in all groups of mice regardless of the brand of PZQ used, but with better results obtained with CD isolate rather than the EE2 isolate. Biltricide and Distocide showed higher C_max and AUC_0–6h in normal mice, in addition to higher worm reduction with least inhibition of CYP450 and CYT b5 in EE2-infected mice. PZQ T3A, Bilharzid and Epiquantel showed, in addition to lower efficacy, higher K_el, lower t_1/2e, C_max and AUC_0–6h. The 32–46% reduction of their bioavailability reflected on their antischistosomal efficacy and recovery of drug metabolizing enzymes. Quality of generic PZQ should include, in addition to examining the physicochemical characteristics of the brands, biological testing including efficacy and bioavailability studies.     

Single Versus Double Dose Praziquantel Comparison on Efficacy and Schistosoma mansoni Re-Infection in Preschool-Age Children in Uganda: A Randomized Controlled Trial

Background

Schistosoma mansoni infection is proven to be a major health problem of preschool-age children in sub-Saharan Africa, yet this age category is not part of the schistosomiasis control program. The objective of this study was to compare the impact of single and double dose praziquantel (PZQ) treatment on cure rates (CRs), egg reduction rates (ERRs) and re-infection rates 8 months later, in children aged 1-5 years living along Lake Victoria, Uganda.

Methodology/Principal Findings

Infected children (n= 1017) were randomized to receive either a single or double dose of PZQ. Initially all children were treated with a single standard oral dose 40 mg/kg body weight of PZQ. Two weeks later a second dose was administered to children in the double dose treatment arm. Side effects were monitored at 30 minutes to 24 hours after each treatment. Efficacy in terms of CRs and ERRs for the two treatments was assessed and compared 1 month after the second treatment. Re-infection with S. mansoni was assessed in the same children 8 months following the second treatment. CRs were non-significantly higher in children treated with two 40 mg/kg PZQ doses (85.5%; 290/339) compared to a single dose (83.2%; 297/357). ERRs were significantly higher in the double dose with 99.3 (95%CI: 99.2-99.5) compared with 98.9 (95%CI: 98.7-99.1) using a single dose, (P = 0.01). Side effects occurred more frequently during the first round of drug administration and were mild and short-lived; these included vomiting, abdominal pain and bloody diarrhea. Overall re-infection rate 8 months post treatment was 44.5%.

Conclusions

PZQ is efficacious and relatively safe to use in preschool-age children but there is still an unmet need to improve its formulation to suit small children. Two PZQ doses lead to significant reduction in egg excretion compared to a single dose. Re-infection rates with S. mansoni 8 months post treatment is the same among children irrespective of the treatment regimen.     

Role of sulfurous mineral water and sodium hydrosulfide as potent inhibitors of fibrosis in the heart of diabetic rats

This study examined the downstream signaling whereby hyperglycemia may lead to myocardial fibrosis and apoptosis in the left ventricle of diabetic rats. The effects of sulfurous mineral water or sodium hydrosulfide (NaHS) as possible modulators were also examined. Sulfurous mineral water (as drinking water) and NaHS (14 μmol/kg/day, IP) were administered for 7 week to rats with streptozotocin (STZ)-induced diabetes. Hyperglycemia, overproduction of glycated hemoglobin (HbA1C) and serum decline in insulin, C-peptide and insulin like growth factor-I (IGF-I) were observed in diabetic rats. Up-regulation of gene expressions of nuclear factor (NF-κB), profibrogenic growth factor such as transforming growth factor-β1 (TGF-β1), matrix metalloproteniase-2 (MMP-2), procollagen-1 and Fas ligand (Fas-L) were observed in the left ventricle of diabetic rats. A linear positive correlation between TGF-β1 and MMP-2 was also detected in diabetic group. An increase in hydroxyproline level and a disturbance in oxidative balance were detected in heart of diabetic rats. Sulfurous mineral water and NaHS treatment possibly, by improving cardiac GSH level, counteracted the enhanced expression of NF-κB, the profibrogenic and apoptotic parameters. Histopathological examination was in accordance with the biochemical and molecular findings of this study. We suggest a novel therapeutic approach of sulfurous mineral water and exogenous supplementation of H₂S in diabetic cardiomyopathy.     

Selective activation of Toll-like receptor 7 in activated hepatic stellate cells may modulate their profibrogenic phenotype

Cholestatic liver injury may activate HSCs (hepatic stellate cells) to a profibrogenic phenotype, contributing to liver fibrogenesis. We have previously demonstrated the involvement of TLR (Toll-like receptor) 7?in the pathogenesis of biliary atresia. In the present study we investigated the ability of TLR7 to modulate the profibrogenic phenotype in HSCs. Obstructive jaundice was associated with significant down-regulation of TLR7. Primary HSCs isolated from BDL (bile duct ligation) rats with obstructive jaundice exhibited reduced expression of TLR7 and increased expression of α-SMA (α-smooth muscle actin) and collagen-α1 compared with sham rats, reflecting HSC-mediated changes. Treatment of primary activated rat HSCs and rat T6 cells with CL075, a TLR7 and TLR8 ligand, significantly decreased expression of MCP-1 (monocyte chemotactic protein-1), TGF-β1 (transforming growth factor-β1), collagen-α1 and MMP-2 (matrix metalloproteinase-2), and inhibited cell proliferation and migration. In contrast, silencing TLR7 expression with shRNA (short hairpin RNA) in T6 cells effectively blocked the effects of CL075 stimulation, reversing the changes in MCP-1, TGF-β1 and collagen-α1 expression and accelerating cell migration. Our results indicate that obstructive jaundice is associated with down-regulation of TLR7 and up-regulation of profibrogenic gene expression in HSCs. Selective activation of TLR7 may modulate the profibrogenic phenotype in activated HSCs associated with cholestatic liver injury.     

The antifibrotic effects of TGF-β1 siRNA on hepatic fibrosis in rats

Background/aims: Hepatic fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSCs), which proliferate during fibrotic liver injury. Transforming growth factor (TGF)-β1 is the dominant stimulus for extracellular matrix (ECM) production by stellate cells. Our study was designed to investigate the antifibrotic effects of using short interference RNA (siRNA) to target TGF-β1 in hepatic fibrosis and its mechanism in rats exposed to a high-fat diet and carbon tetrachloride (CCL4). Methods: A total of 40 healthy, male SD (Sprague–Dawley) rats were randomly divided into five even groups containing of eight rats each: normal group, model group, TGF-β1 siRNA 0.125 mg/kg treatment group, TGF-β1 siRNA 0.25 mg/kg treatment group and TGF-β1 siRNA negative control group (0.25 mg/kg). CCL4 and a high-fat diet were used for 8 weeks to induce hepatic fibrosis. All the rats were then sacrificed to collect liver tissue samples. A portion of the liver samples were soaked in formalin for Hematoxylin–Eosin staining, classifying the degree of liver fibrosis, and detecting the expression of type I and III collagen and TGF-β1; the remaining liver samples were stored in liquid nitrogen to be used for detecting TGF-β1 by Western blotting and for measuring the mRNA expression of type I and III collagen and TGF-β1 by quantitative real-time polymerase chain reaction. Results: Comparing the TGF-β1 siRNA 0.25 mg/kg treatment group to the model group, the TGF-β1 siRNA negative control group and the TGF-β1 siRNA 0.125 mg/kg treatment group showed significantly reduced levels of pathological changes, protein expression and the mRNA expression of TGF-β1, type I collagen and type III collagen (P < 0.01). Conclusions: Using siRNA to target TGF-β1 can inhibit the expression of TGF-β1 and attenuate rat hepatic fibrosis induced by a high-fat diet and CCL4. A possible mechanism is through the down-regulation of TGF-β1 expression, which could inhibit HSC activation, as well as the proliferation and collagen production of collagen reducing, so that collagen deposition in the liver is reduced.     

A Latent Markov Modelling Approach to the Evaluation of Circulating Cathodic Antigen Strips for Schistosomiasis Diagnosis Pre- and Post-Praziquantel Treatment in Uganda

Regular treatment with praziquantel (PZQ) is the strategy for human schistosomiasis control aiming to prevent morbidity in later life. With the recent resolution on schistosomiasis elimination by the 65th World Health Assembly, appropriate diagnostic tools to inform interventions are keys to their success. We present a discrete Markov chains modelling framework that deals with the longitudinal study design and the measurement error in the diagnostic methods under study. A longitudinal detailed dataset from Uganda, in which one or two doses of PZQ treatment were provided, was analyzed through Latent Markov Models (LMMs). The aim was to evaluate the diagnostic accuracy of Circulating Cathodic Antigen (CCA) and of double Kato-Katz (KK) faecal slides over three consecutive days for Schistosoma mansoni infection simultaneously by age group at baseline and at two follow-up times post treatment. Diagnostic test sensitivities and specificities and the true underlying infection prevalence over time as well as the probabilities of transitions between infected and uninfected states are provided. The estimated transition probability matrices provide parsimonious yet important insights into the re-infection and cure rates in the two age groups. We show that the CCA diagnostic performance remained constant after PZQ treatment and that this test was overall more sensitive but less specific than single-day double KK for the diagnosis of S. mansoni infection. The probability of clearing infection from baseline to 9 weeks was higher among those who received two PZQ doses compared to one PZQ dose for both age groups, with much higher re-infection rates among children compared to adolescents and adults. We recommend LMMs as a useful methodology for monitoring and evaluation and treatment decision research as well as CCA for mapping surveys of S. mansoni infection, although additional diagnostic tools should be incorporated in schistosomiasis elimination programs.     

Effect of gold nanoparticles on mice splenomegaly induced by schistosomiasis mansoni

Schistosomiasis is still one of the main parasitic diseases that affect human health in tropical regions. Whilst praziquantel (PZQ) is the main classic antischistosomal drug, the need for new drugs is still a must due to the low effectiveness of the drug on the schistosome young worms, and the evolving of PZQ resistant strains. Nanotechnology is one of the most important recent and current methods used to treat human diseases including parasitic ones. Therefore, the present study aimed to examine the curative role of gold nanoparticles (GNPs) on splenic tissue of mice infected with Schistosoma mansoni Sambon, 1907. High-resolution transmission electron microscopy was used for characterization of nanoparticles (NP). GNPs of 1 mg/kg mice body weight were inoculated into mice infected with S. mansoni. The parasite caused deteriorations in histological architecture of the spleen tissue, and splenomegaly. Additionally, the parasite induced a significant reduction in splenic tissue glutathione levels; however, the concentrations of nitric oxide and malondialdehyde were significantly increased. Treatment of mice with GNPs reduced the extent of histological impairment and oxidative stress in spleen tissue. Therefore, our results demonstrate the protective role of GNPs against splenic damage in mice infected with S. mansoni.     

烧伤膏对小鼠皮肤烫伤创面愈合的修复作用研究

目的:探讨烧伤膏对烫伤小鼠皮肤创面修复的可能作用机制。方法:将50只小鼠随机分为5组:正常组、模型组,烧伤膏高、中、低剂量组。除正常组和模型组外,烧伤膏实验组小鼠每天外涂烧伤膏治疗,连用15天。治疗结束后,采用Masson染色技术检测各组小鼠皮肤厚度及细胞病理形态;采用生化法检测皮肤中羟脯氨酸(Hyp)含量;采用ELISA技术检测皮肤中的TNF-α,IL-1β、Collagen I、EGF和TGF-β1的含量。结果:与正常组相比,模型组小鼠皮肤烫伤创面可见表皮细胞脱落,结构模糊,细胞变性坏死,表皮和真皮厚度明显减少,胶原纤维变薄,排列紊乱无序,呈断裂状;烧伤后创面局部组织中Hyp、TNF-α、IL-1β的含量显著升高(P0.01,P0.01,P0.01),而EGF、TGF-β1和Collagen I含量均明显减少(P0.01,P0.01,P0.01),而应用烧伤膏治疗15天后,上述各项实验指标明显得到改善。结论:烧伤膏抑制创面早期感染,减少胶原蛋白的分解和促进后期创面修复的作用可能与抑制炎性细胞因子和增加皮肤相关生长因子表达的作用机制有关。     

Effects of Pentoxifylline on Liver and Thymus of Plasmodium berghei ANKA Infected Swiss Albino Mice

Infection of Swiss albino mice with Plasmodium berghei ANKA (PbA), a lethal strain, led to injury of the liver, thymic atrophy and high host mortality. Action of pentoxifylline (PTX), an inhibitor of TNF-α (tumor necrosis factor alpha), was investigated on hepatic necrosis, thymic atrophy, increased percentage of Sub G0/G1 hepatic and thymic populations, parasitemia and survivability of the infected mice host. Our data suggest the importance of PTX in mice survival and curing of liver cirrhosis, without affecting the parasitemic condition of the infected mice. Histomorphological changes were well evident from the appearance of hypertrophied hepatic cells with abundance of pigments. In the thymus no cortico-medullary demarcation was observed with presence of hypertrophied thymocytes. Hyperplasia of hepatic cells in the Sub-G0/G1 stage as revealed by flow cytometric analyses, was suppressed by PTX which is an indication of apoptotic effect of PTX in mice. Mice treated with PTX showed a significant decrease of necrotic areas in liver and thymus, suggesting that PTX treatment controls TNF-α effect, and thus PTX may be used as an adjuvant in the treatment of malaria.     

Latent infection by γherpesvirus stimulates profibrotic mediator release from multiple cell types

Although γherpesvirus infections are associated with enhanced lung fibrosis in both clinical and animal studies, there is limited understanding about fibrotic effects of γherpesviruses on cell types present in the lung, particularly during latent infection. Wild-type mice were intranasally infected with a murine γherpesvirus (γHV-68) or mock-infected with saline. Twenty-eight days postinfection (dpi), ～14 days following clearance of the lytic infection, alveolar macrophages (AMs), mesenchymal cells, and CD19-enriched cell populations from the lung and spleen express M(3) and/or glycoprotein B (gB) viral mRNA and harbor viral genome. AMs from infected mice express more transforming growth factor (TGF)-β(1), CCL2, CCL12, TNF-α, and IFN-γ than AMs from mock-infected mice. Mesenchymal cells express more total TGF-β(1), CCL12, and TNF-α than mesenchymal cells from mock-infected mice. Lung and spleen CD19-enriched cells express more total TGF-β(1) 28 dpi compared with controls. The CD19-negative fraction of the spleen overexpresses TGF-β(1) and harbors viral genome, but this likely represents infection of monocytes. Purified T cells from the lung harbor almost no viral genome. Purified T cells overexpress IL-10 but not TGF-β(1). Intracellular cytokine staining demonstrated that lung T cells at 28 dpi produce IFN-γ but not IL-4. Thus infection with a murine γherpesvirus is sufficient to upregulate profibrotic and proinflammatory factors in a variety of lung resident and circulating cell types 28 dpi. Our results provide new information about possible contributions of these cells to fibrogenesis in the lungs of individuals harboring a γherpesvirus infection and may help explain why γHV-68 infection can augment or exacerbate fibrotic responses in mice.     

Drug-metabolizing enzymes and praziquantel bioavailability in mice harboring Schistosoma mansoni isolates of different drug susceptibilities

The level of drug-metabolizing enzymes (cytochrome P450 [CYP450] and cytochrome b5 [cyt b5]) and the bioavailability of praziquantel (PZQ) were investigated in batches of mice infected with Schistosoma mansoni displaying either a decreased susceptibility to PZQ ("EE2" and "BANL"-isolates), or a normal susceptibility to the drug ("CD" isolate). Each batch was divided into 2 groups. The first group was further subdivided into 5 subgroups. Subgroups 1 to 4 were treated 7 wk postinfection (PI) with oral PZQ at 25, 50, 100, and 200 mg/kg for 5 consecutive days, whereas the fifth subgroup was administered the vehicle only as control. Animals were perfused 9 wk PI, and worms were counted to estimate PZQ ED50. CYP450 and cyt b5 were examined in hepatic microsomes of infected untreated mice and of infected mice treated with 25 and 200 mg/ kg PZQ. The second group was given PZQ 7 wk PI and was further subdivided into 11 subgroups, killed at 2, 5, 15, 30, 60, 90, 120, 150, 180, 240, and 360 min postdosing to study pharmacokinetic parameters of PZQ. Mice harboring S. mansoni isolates having higher PZQ ED50 (170.3 mg/kg for EE2 and 249.9 mg/kg for BANL vs. 82.96 mg/kg for CD) had higher levels of CYP450 and cyt b5, a PZQ Cmax decreased by 19-30% and area under the serum concentration-time curve0-6 hr decreased by 57-74%. Data suggest that S. mansoni isolates that are less sensitive to PZQ induce a lower inhibition of hepatic drug-metabolizing enzymes, with a consequently higher metabolic transformation of PZQ.     

Transforming growth factor-β and Th17 responses in resistance to primary murine schistosomiasis mansoni

Discovery of the T-helper (Th) 17 cell lineage and functions in immune responses of mouse and man prompted us to investigate the role of transforming growth factor-beta (TGF-β) and interleukin (IL)-17 in innate resistance to murine schistosomiasis mansoni. Schistosoma mansoni-infected BALB/c and C57BL/6 mice were administered with recombinant TGF-β or mouse monoclonal antibody to TGF-β to evaluate the impact of this cytokine on host immune responses against lung-stage schistosomula, and subsequent effects on adult worm parameters. Developing schistosomula elicited increase in peripheral blood mononuclear cells (PBMC) mRNA expression and/or plasma levels of IL-4, IL-17, and interferon-gamma (IFN-γ), cytokines known to antagonize each other, resulting in impaired Th1/Th2, and Th17 immune responses and parasite evasion. Mice treated with TGF-β showed elevated PBMC mRNA expression of IL-6, IL-17, TGF-β, and TNF-α mRNA and increased IL-23 and IL-17 or TGF-β plasma levels, associated with significantly (P < 0.02–<0.0001) lower S. mansoni adult worm burden compared to controls in both mouse strains, thus suggesting that TGF-β led to heightened Th17 responses that mediated resistance to the infection. Mice treated with antibody to TGF-β showed increase in PBMC mRNA expression and plasma levels of IL-4, IL-12p70, and IFN-γ, and significantly (P < 0.02 and <0.0001) reduced worm burden and liver worm egg counts than untreated mice, indicating that Th1/Th2 immune responses were potentiated, resulting in significant innate resistance to schistosomiasis. The implications of these observations for schistosome immune evasion and vaccination were discussed.     

Association of cytokines in hepatitis E with pregnancy outcome

AimsThe aim of this study was to evaluate tumour necrosis factor-alpha (TNF-α), interleukin (IL)-6, interferon gamma (IFN-γ) and transforming growth factor-beta1 (TGF-β1) in hepatitis E infection during pregnancy and its relation with pregnancy outcome.MethodsA total of 272 pregnant and 219 non-pregnant women with hepatitis and 262 age and gestational age matched healthy pregnant women and 208 age matched, healthy non-pregnant women were evaluated on the basis of history, clinical examination, liver function profile. Serological tests of hepatitis A, B, C and E and cytokines using commercially available (ELISA) kits. The patients with hepatitis E were further evaluated for viral load by Real Time PCR. All these were followed till delivery for pregnancy outcome.ResultsHEV viral load in acute viral hepatitis (AVH) and fulminant hepatic failure (FHF) of pregnant women were comparatively higher than non-pregnant women. Significantly higher levels of TNF-α, IL-6, IFN-γ and TGF-β1 were present in HEV infected pregnant women compared to non-pregnant women and controls. TNF-α, IL-6 and IFN-γ had significant positive correlation with viral load, serum bilirubin and prothrombin time in pregnant women. Higher levels of all four cytokines were found in pregnant women with HEV infection having adverse pregnancy outcome compared to that of pregnant women with non-HEV infection and controls.ConclusionIn conclusion, severity of HEV infection and associated adverse pregnancy outcome might be mediated by cytokine in pregnancy.     

Immunomodulatory effects of IL-12 released from poly-N-acetyl glucosamine gel matrix during schistosomiasis infection

We have reported recently that Interleukin-12 (IL-12) released from poly-N-acetyl glucosamine gel matrix (F2 gel/IL-12) is more effective than free IL-12 to enhance vaccination of mice with Schistosoma soluble worm antigen preparation. The aim of this study is to evaluate the effect of F2 gel/IL-12 on the inflammatory responses in mice undergoing schistosomiasis infection in absence of vaccination. To achieve this, mice undergoing Schistosoma mansoni infection or cured from this infection, after treatment with praziquantil (PZQ), were treated with subcutaneous injection of IL-12 for 3 consecutive days or once with F2 gel loaded with IL-12 (F2 gel/IL-12). The treatment was started on day 35 days after infection. For infection, mice were infected with 100 cercariae of S. mansoni using tail immersion method. We found that treatment with F2 gel/IL-12 induced significant decreases in the egg burden with a moderate reduction in the size of granuloma and decrease in the cellular granulomatous reaction in the lung as compared to infected mice treated with IL-12. These effects of F2 gel/IL-12 were more pronounced in infected mice previously treated with the anti-schistosomal drug PZQ. The total numbers of white blood cells in all treated mice showed similar profile. Treatment with IL-12 or F2 gel/IL-12, however, showed significant reduction in the number of mononuclear cells when compared with non-treated infected mice. In conclusion, this study showed the ability of IL-12 released from F2 gel to lower the inflammatory response to Schistosoma infection even in absence of vaccination.     

Altered response of strain of Schistosoma mansoni to oxamniquine and praziquantel

The susceptibility of a fourth generation Ouh strain (Paranapanema Valley, S?o Paulo, Brazil) of Schistosoma mansoni to oxamniquine (OXA) and praziquantel (PZQ) was studied. Ten groups of 13 female albino mice each were infected with 70 cercariae per animal. These mice were medicated orally on the 50th day after infection. Five groups were given OXA doses of 0, 100, 200, 300 and 400 mg/kg (single doses) and the rest were treated with PZQ doses of 0, 100, 200, and 250 mg/kg/5 days. Each group was sub-divided: 8 animals underwent perfusion after 15 days treatment, 5 mice followed up for oviposition and their feces were tested every 15 days for miracidia hatching. The efficacy of the OXA doses of 100 and 200 mg/kg was 66% and 91.4%, respectively and for the 100 mg/kg PZQ dose it was 90.1%. The follow-up groups with 100 and 200 mg/kg of OXA and PZQ, 100 and 150 mg/kg, showed that they re-established the oviposition after a period of 60 to 75 days of treatment. The ED50 was 69.6 mg/kg OXA and 39.4 mg/kg PZQ. The results show the tolerance of the Ouh strain to a dose of 100 mg with both drugs and they appoint the need for a dose review during the follow up of the oviposition and in monitoring phenomena in the field.     

Green tea (Camellia sinesis) ameliorates female Schistosoma mansoni-induced changes in the liver of Balb/C mice

This study was designed to assess the effect of green tea, an aqueous extract of Camellia sinensis, on the oxidative stress, antioxidant defense system and liver pathology of Schistosoma mansoni-infected mice. Green tea at concentration of 3% (w/v) was given orally to treated mice as sole source of drinking water from the end of the 4th week to the end of 10th week post-infection; untreated mice were allowed to drink normal water. The data of the studied S. mansoni-infected mice exhibited a suppression of hepatic total antioxidant capacity, superoxide dismutase (SOD), catalase (CAT) activity and glutathione content. The liver lipid peroxidation was deleteriously elevated in S. mansoni-infected mice. The hepatic total protein content, AST and ALT activities were profoundly decreased in the S. mansoni-infected mice. Most hepatocytes were damaged and showed abnormal microscopic appearance with aggressive necrosis. Both total protein and glycogen levels have been greatly reduced as indicated by histochemical examination. The treatment of S. mansoni-infected mice with green tea succeeded to suppress oxidative stress by decreasing the lipid peroxides but failed to significantly enhance the antioxidant defense system and deteriorated changes owing to liver damage and necrosis. In consistence with biochemical data, histopathological and histochemical data indicated that treatment of S. mansoni-infected mice with green tea could ameliorate hepatocytes thus reduce cellular necrosis and partially restore both total protein and glycogen levels. Thus, the study concluded that the green tea suppresses the oxidative stress through its constituent with free radicals scavenging properties rather than through the endogenous antioxidant defense system.