Schistosoma japonicum infection associated with membranous nephropathy: a case report.

BACKGROUND: Schistosomiasis is one of the most contagious parasitic diseases affecting humans; however, glomerular injury is a rare complication mainly described with Schistosoma mansoni infection. We report a case of membranous nephropathy associated with Schistosoma japonicum infection in a Chinese man. CASE PRESENTATION: A 51-year-old Chinese male with a long history of S. japonicum infection presented to the hospital with a slowly progressing severe lower limb edema and foaming urine for over 5 months. Serum S. japonicumantigen test was positive and immunohistochemistry showed that the glomeruli were positive for the antigens. The renal pathologic diagnosis was stage III membranous nephropathy. The patient was treated with glucocorticoid, praziquantel, and an angiotensin-converting enzyme inhibitor. The edema in both lower limbs disappeared within 2 weeks, but his renal function declined progressively and proteinuria persisted after 5 months of therapy. CONCLUSIONS: Different classes of schistosomal glomerulopathy have completely different clinical manifestation and prognosis. Therefore, efforts should focus on alleviating symptoms, prevention, and early detection. S. japonicumassociated with membranous nephropathy may show a good curative effect and prognosis. However, it is necessary to monitor the renal function in such patients.

Sodium butyrate ameliorates Schistosoma japonicum-induced liver fibrosis by inhibiting HMGB1 expression.

Schistosomiasis is a prevalent zoonotic parasitic disease caused by schistosomes. Its main threat to human health is hepatic granuloma and fibrosis due to worm eggs. Praziquantel remains the first choice for the treatment of schistosomiasis but has limited benefit in treating liver fibrosis. Therefore, the need to develop effective drugs for treating schistosomiasis-induced hepatic fibrosis is urgent. High-mobility group box 1 protein (HMGB1) is a potential immune mediator that is highly associated with the development of some fibrotic diseases and may be involved in the liver pathology of schistosomiasis. We speculated that HMGB1 inhibitors could have an anti-fibrotic effect. Sodium butyrate (SB), a potent inhibitor of HMGB1, has shown anti-inflammatory activity in some animal disease models. In this study, we evaluated the effects of SB on a murine schistosomiasis model. Mice were percutaneously infected with 20 ± 2 cercariae of Schistosoma japonicum. SB (500 mg/kg/day) was administered every 3 days for the entire experiment period. The activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), liver histopathology, HMGB1 expression, and the levels of interferon gamma (IFN-γ), transforming growth factor-ß1 (TGF-ß1), and interleukin-6 (IL-6) in serum were analyzed. SB reduced hepatic granuloma and fibrosis of schistosomiasis, reflected by the decreased levels of ALT and AST in serum and the reduced expression of pro-inflammatory and fibrogenic cytokines (IFN-γ, TGF-ß1, and IL-6). The protective effect could be attributable to the inhibition of the expression of HMGB1 and release by SB.

The ABL kinase inhibitor imatinib causes phenotypic changes and lethality in adult Schistosoma japonicum.

Schistosomiasis caused by different species of schistosome parasites is one of the most debilitating helminthic diseases of humans worldwide. For decades, chemotherapy is the main method of controlling schistosomiasis. However, the fear of drug resistance has motivated the search for alternatives. It has been demonstrated that the ABL kinase inhibitor imatinib affected the development and survival of Schistosoma mansoni in vitro; however, there is still lack of information on whether imatinib also affects other schistosome species such as Schistosoma japonicum. In the present study, the anti-schistosomal potency of imatinib on adult S. japonicum was investigated in vitro, and the results showed that imatinib had a significant impact on various physiological processes of S. japonicum adult worms. Besides its negative effects on worm motility, pairing stability, and gonad development, imatinib caused pathological changes in the gastrodermis as well as the death of the parasite. Our findings suggest that imatinib is an intriguing candidate for further development as an option to fight S. japonicum.

Praziquantel Targets M1 Macrophages and Ameliorates Splenomegaly in Chronic Schistosomiasis.

Splenomegaly is a common feature of many infectious diseases, including schistosomiasis japonica. However, the immunopathogenesis and the treatment of splenomegaly due to schistosomiasis have been largely neglected. Praziquantel (PZQ), a classical schistosomicide, has been demonstrated by us and others to have antifibrotic and anti-inflammatory activities against schistosomiasis. In this study, we investigated the effect of PZQ on alleviating the splenomegaly caused by Schistosoma japonicum infection in mice. The results showed that the number of macrophages, especially the number of M1 macrophages, was significantly increased in the enlarged spleens of infected mice (P < 0.001). After PZQ treatment for 4 weeks, the number of splenic macrophages, especially the number of M1 macrophages, was significantly reduced (P < 0.001) by the way of apoptosis, and another schistosomicide, mefloquine, had no effect either on the splenomegaly or on reducing the number of macrophages. Furthermore, by using the murine macrophage line RAW 264.7, we found that PZQ could inhibit the formation of the NLRP3 inflammasome and attenuate phagocytic activity in M1 macrophages. Thus, our studies suggest that PZQ plays a powerful role in ameliorating the splenomegaly caused by S. japonicum infection, which presents a new strategy for the therapy of splenomegaly resulting from other pathological conditions.

Sorafenib and praziquantel synergistically attenuate Schistosoma japonicum-induced liver fibrosis in mice.

Liver fibrosis is an important process that occurs in most types of chronic liver diseases and often results in the end stage of liver diseases, such as cirrhosis, portal hypertension, and hepatocellular carcinoma. Sorafenib, a multiple tyrosine kinase inhibitor, has been shown to inhibit liver fibrosis in multiple experimental fibrosis mouse and rat models. The aim of this study was to test the therapeutic effect of sorafenib on liver fibrosis induced by infection with a parasite, Schistosoma japonicum, in mice. Mice were percutaneously infected through the abdomen with Schistosoma cercariae to develop a schistosomula liver fibrosis model. Eight weeks after infection, infected mice were treated with the anti-parasitic agent praziquantel for 2 days and sorafenib for 2 weeks. Hepatic histopathological changes were assessed using hematoxylin and eosin (HE) and Masson's trichome staining. The hepatic expression levels of collagen I, collagen III, alpha-smooth muscle actin (α-SMA), platelet-derived growth factor (PDGF), and PDGF receptor-beta (PDGFR-ß) were analyzed by immunohistochemistry and western blot. Praziquantel administration alone but not sorafenib reduced liver fibrosis, and the combination of praziquantel and sorafenib significantly attenuated liver fibrosis in S. japonicum-infected mice. Moreover, sorafenib plus praziquantel markedly decreased the hepatic deposition of collagen and expression of fibrogenic genes in these mice. In conclusion, the use of sorafenib following praziquantel treatment may represent a potential therapeutic strategy for liver fibrosis induced by S. japonicum in patients.

[Schistosomiasis japonica in a patient who emigrated from China: a case report].

A 37-year-old woman exhibited abnormal liver enzyme levels without any symptoms at a medical check-up. She was born and raised in Hubei, China, and had immigrated to Japan in her mid-thirties. Ultrasonography revealed an enlarged caudate lobe of the liver and a wide moniliform portal vein, whereas computed tomography revealed lined calcification on the surface of the liver and on the collateral vein of the portal vein. Although imaging studies provided no critical findings, the crucial information that led to diagnosis was gained through the interview with the patient. Schistosomiasis japonica was known to be prevalent in her hometown, and she reported that her father's past infection was due to Schistosoma japonicum. Serological analysis demonstrated high levels of anti-S. japonicum antibodies, which were reduced using praziquantel administration.

Antischistosomiasis Liver Fibrosis Effects of Chlorogenic Acid through IL-13/miR-21/Smad7 Signaling Interactions In Vivo and In Vitro.

This study investigated the antischistosomiasis liver fibrosis effects of chlorogenic acid (CGA) on interleukin 13 (IL-13)/microRNA-21 (miR-21)/Smad7 signaling interactions in the hepatic stellate LX2 cell line and schistosome-infected mice. The transfection was based on the ability of the GV273-miR-21-enhanced green fluorescent protein (EGFP) and GV369-miR-21-EGFP lentiviral system to up- or downregulate the miR-21 gene in LX2 cells. The mRNA expression of miR-21, Smad7, and connective tissue growth factor (CTGF) and the protein expression of Smad7, CTGF, Smad1, phosphor-Smad1 (p-Smad1), Smad2, p-Smad2, Smad2/3, p-Smad2/3, transforming growth factor ß (TGF-ß) receptor I, and α-smooth muscle actin (α-SMA) was assayed. Pathological manifestation of hepatic tissue was assessed for the degree of liver fibrosis in animals. The results showed that CGA could inhibit the mRNA expression of miR-21, promote Smad7, and inhibit CTGF mRNA expression. Meanwhile, CGA could significantly lower the protein levels of CTGF, p-Smad1, p-Smad2, p-Smad2/3, TGF-ß receptor I, and α-SMA and elevate the Smad7 protein level. In vivo, with treatment with CGA, the signaling molecules of IL-13/miR-21/Smad7 interactions were markedly regulated. CGA could also reduce the degree of liver fibrosis in pathological manifestations. In conclusion, CGA could inhibit schistosomiasis-induced hepatic fibrosis through IL-13/miR-21/Smad7 signaling interactions in LX2 cells and schistosome-infected mice and might serve as an antifibrosis agent for treating schistosomiasis liver fibrosis.

Vascular endothelial growth factor promotes the activation of hepatic stellate cells in chronic schistosomiasis.

The activation of hepatic stellate cells (HSCs) is a key event in fibrotic pathogenesis. However, the mechanism involving activation of HSCs in chronic schistosomiasis is not entirely clear. Human HSC LX-2 and human umbilical vein endothelial cells (ECs) were cultured with Schistosoma japonicum antigens (SA) in vitro. Fibrosis-associated genes and cell proliferation were analyzed. HSCs were isolated from mice of chronic schistosomiasis with or without praziquantel (PZQ) treatment, followed by the microarray analysis for the liver fibrosis-associated pathways. Although SA inhibited the activation and proliferation of HSCs, it induced the EC proliferation and vascular endothelial growth factor-a (VEGF) production. VEGF significantly increased the proliferation of HSCs and upregulated the expression of collagen and α-smooth muscle actin. For in vivo study, we found that several fibrosis-associated pathways were involved in the HSCs during the reversal of liver fibrosis caused by schistosomiasis, including VEGF, platelet-derived growth factor, tumor necrosis factor and endothelin-1 pathways. The Ingenuity Pathway Analysis showed that VEGF directly regulated several pro-fibrotic and immune cytokine genes in HSCs, including integrin, fibronectin, interferon-γ, interleukin (IL)-6 and IL-10. Our data indicated the critical role of VEGF signaling in HSC activation in chronic schistosomiasis and highlighted several promising genes and pathways in HSCs as potential targets for therapeutic treatment of liver fibrosis.

Clinical diagnostic value of viable Schistosoma japonicum eggs detected in host tissues.

BACKGROUND: Schistosomiasis, one of the neglected tropical diseases, is endemic in more than 70 countries. However, the clinical diagnosis of patients with a low degree of infection is an unsolved technical problem. In areas endemic for schistosomiasis japonica, proctoscopy detection of eggs has been one method used for clinical diagnosis. However, it is often a challenge to find typical live eggs and it is difficult to distinguish live eggs from large numbers of partially degraded and/or completely degraded eggs within colon biopsy tissue. To address this problem, we tested six different morphological and biochemical/molecular markers (ALP; morphological characteristics of egg; CalS (calcified substance); AOS (antioxidase); SDHG (succinic dehydrogenase) and SjR2 mRNA (retrotransposons 2 of S.japonicum genome mRNA)), including four new markers (CalS; AOS; SDHG and SjR2 mRNA.), to determine the viability of S. japonicum eggs deposited in human and mouse colon tissues. Our ultimate aim is to obtain a new method that is more sensitive, practical and accurate to clinically diagnose schistosomiasis. METHODS: Tissue samples were collected from mice at six different time points during S. japonicum infection with or without treatment with praziquantel (PZQ). Four new biochemical or molecular markers were used for the detection of egg viability from mouse liver and intestinal samples: CalS; AOS; SDHG and SjR2 mRNA. Subsequently, all markers were employed for the detection and analysis of eggs deposited in biopsy materials from patients with suspected schistosomiasis japonica for clinical evaluation. Microscopic examination of the egg morphology, worm burden in vivo and ALP (alkaline phosphatase) levels were used as a reference standard to evaluate the sensitivity and reliability of four new markers detecting egg viability. RESULTS: The results of the study showed that the morphology of S. japonicum eggs deposited in tissues of hosts with schistosomiasis, especially cases with chronic schistosomiasis, is complex and egg viability is difficult to judge morphologically, particularly eggs with a fuzzy structure or partially modified eggs. We found that the majority of the viable schistosome eggs determined by four new markers (CalS, AOS, SDHG and SjR2 mRNA) were morphologically difficult to identify. CONCLUSIONS: Among the markers, the most sensitive and specific method was the detection of SjR2 mRNA and the most simple, rapid and practical method was the detection of SDHG. Therefore, the detection of SDHG is the most practical for clinical application and its use could improve the accuracy in diagnosing active schistosome infection.

Field evaluation of a novel molluscicide (niclosamidate) against Oncomelania hupensis, intermediate host of Schistosoma japonicum.

The molluscicidal activity of a novel molluscicide (niclosamidate) was evaluated in field trials against Oncomelania hupensis, the intermediate host of Schistosoma japonicum. The environmental safety of niclosamidate for local fishes was also studied under field conditions. The results showed that, at the dosages of 8.0 g/m2 and 4.0 g/m3, niclosamidate exhibits highly potent molluscicidal activity in the spraying and immersion trials, resulting in mortality rates of up to 81.8 and 72.7%, respectively. Its performance seems to be target-specific, with good molluscicidal ability observed for Oncomelania hupensis snails, but very low toxicity for local fishes and other aquatic organisms. The results suggest that niclosamidate can be used as an alternative molluscicide for snail control, which would be particularly applicable in semi-commercial or commercial aquaculture ponds.

Function of Nanos1 gene in the development of reproductive organs of Schistosoma japonicum.

Nanos is a necessary factor in the differentiation and migration of primordial germ cells. It is closely associated with the development of genitalia in a wide range of species. We questioned whether Nanos was involved in the reproductive organ development of Schistosoma japonicum. Firstly, by in situ hybridization, S. japonicum Nanos1 (SjNanos1) gene was expressed mainly in reproductive organs of S. japonicum. Then, the paired schistosome of 28 days post-infection (dpi) was transfected with SjNanos1 small interfering RNA three times and cultured in vitro for 10 days. SjNanos1 expression suppression in the mRNA and protein levels were confirmed compared to that of the controls. The morphological changes in reproductive organs and egg production were observed after SjNanos1 gene knockdown. The results observed by confocal laser scanning microscopy showed significant changes in the morphology of reproductive organs of parasites, especially the female ovaries, vitellarium, and the male testes, after RNAi. In addition, SjNanos1 silencing also induced the reduction of eggs, and affected the changes of reproduction-related genes, like Pumilio, CNOT6L, and Fs800. Therefore, our findings demonstrate that the SjNanos1 gene is essential in the development of reproductive organs and the egg production of S. japonicum.

Long-term effectiveness of the integrated schistosomiasis control strategy with emphasis on infectious source control in China: a 10-year evaluation from 2005 to 2014.

Schistosomiasis is a neglected tropical parasitic disease of great public health significance worldwide. Currently, mass drug administration with praziquantel remains the major strategy for global schistosomiasis control programs. Since 2005, an integrated strategy with emphasis on infectious source control was implemented for the control of schistosomiasis japonica, a major public health concern in China, and pilot studies have demonstrated that such a strategy is effective to reduce the prevalence of Schistosoma japonicum infection in both humans and bovines. However, there is little knowledge on the long-term effectiveness of this integrated strategy for controlling schistosomiasis japonica. The aim of this study was to evaluate the long-term effectiveness of the integrated strategy for schistosomiasis control following the 10-year implementation, based on the data from the national schistosomiasis control program released by the Ministry of Health, People's Republic of China. In 2014, there were 5 counties in which the transmission of schistosomiasis japonica had not been interrupted, which reduced by 95.2% as compared to that in 2005 (105 counties). The number of schistosomiasis patients and acute cases reduced by 85.5 and 99.7% in 2014 (115,614 cases and 2 cases) as compared to that in 2005 (798,762 cases and 564 cases), and the number of bovines and S. japonicum-infected bovines reduced by 47.9 and 98% in 2014 (919,579 bovines and 666 infected bovines) as compared to that in 2005 (1,764,472 bovines and 33,736 infected bovines), respectively. During the 10-year implementation of the integrated strategy, however, there was a minor fluctuation in the area of Oncomelania hupensis snail habitats, and there was only a 5.6% reduction in the area of snail habitats in 2014 relative to in 2005. The results of the current study demonstrate that the 10-year implementation of the integrated strategy with emphasis on infectious source has greatly reduced schistosomiasis-related morbidity in humans and bovines. It is concluded that the new integrated strategy has remarkable long-term effectiveness on the transmission of schistosomiasis japonica in China, which facilitates the shift of the national schistosomiasis control program from transmission control to transmission interruption and elimination. However, such a strategy seems to have little effect on the shrinking of areas of snail habitats.

A cross-sectional survey comparing a free treatment program for advanced schistosomiasis japonica to a general assistance program.

The prevalence and intensity of schistosomiasis has dropped dramatically in China due to an effective integrated control program. However, advanced schistosomiasis is becoming a key challenge on the road to elimination. The aims of this study were to compare the disease condition between advanced cases under the general assistance program (GAP) and free treatment program (FTP) and to determine whether the FTP should be popularized to provide an objective reference for policymakers in China's advanced schistosomiasis control program. One hundred and ninety-four patients with schistosomiasis japonica who were enrolled in the GAP or FTP participated in this study. Little significant difference was observed in the potential confounders, including general characteristics, comorbidities, and lifestyle, indicating a similar effect on the pathology of liver damage caused by schistosome infection. There was no apparent difference in the incidence of common clinical symptoms. Furthermore, no significant difference was observed in the ultrasound findings, implying that the GAP and FTP groups shared a similar degree of liver lesion. With the exception of the abnormal rates of aspartate aminotransferase (AST), alkaline phosphatase (ALP), and hyaluronic acid (HA), the other serological indicators were comparable between the groups. Overall, the FTP is not a better option for controlling advanced schistosomiasis in China. It is important to reveal the precise mechanism underlying the pathogenesis of advanced schistosomiasis so that specific approaches to treating and preventing the development of advanced schistosomiasis can be developed and schistosomiasis can be eliminated in China.

Genistein improves schistosomiasis liver granuloma and fibrosis via dampening NF-kB signaling in mice.

In schistosomiasis, egg deposition in the liver contributes to the formation of hepatic granuloma and fibrosis, which are the most serious clinical pathological features. It has been proposed that activation of the nuclear factor kappa B (NF-κB) signaling pathways is closely associated with the development of hepatic granuloma and fibrosis. Genistein has been shown to inhibit the activity of NF-κB signaling pathways, which might be a potential agent to protect against Schistosoma japonicum egg-induced liver granuloma and fibrosis. In this study, liver granuloma and fibrosis were induced by infecting BALB/c mice with 18 ± 3 cercariae of S. japonicum. At the beginning of egg granuloma formation (early phase genistein treatment from 4 to 6 weeks after infection) or after the formation of liver fibrosis (late phase genistein treatment from 6 to 10 weeks after infection), the infected mice were injected with genistein (25, 50 mg/kg). The results revealed that genistein treatment significantly decreased the extent of hepatic granuloma and fibrosis in infected mice. The activity of NF-κB signaling declined sharply after the treatment with genistein, as evidenced by the inhibition of NF-κB-p65, phospho-NF-κB-p65, and phospo-IκB-α expressions, as well as the expression of IκB-α and the messenger RNA (mRNA) expression of inflammatory cytokines (MCP1, TNFα, IL1ß, IL4, IL10) mediated by NF-κB signaling pathways in the early phase of the infection. Moreover, western blot and immunohistochemistry assays demonstrated that the contents of α-smooth muscle actin (α-SMA) and transforming growth factor-ß were dramatically reduced in liver tissue under the treatment of genistein in the late phase of the infection. At the same time, the mRNA expression of MCP1, TNFα, and IL10 was inhibited markedly. These results provided evidence that genistein reduces S. japonicum egg-induced liver granuloma and fibrosis, at least partly due to decreased NF-κB signaling, and subsequently decreased MCP1, TNFα, and IL10 expressions. This implies that genistein can be a potential natural agent against schistosomiasis.

Assessment of the effect of treatment and assistance program on advanced patients with schistosomiasis japonica in China from 2009 to 2014.

Schistosomiasis is one of the most important zoonoses, threatening approximately 800 million people in 78 countries with a loss of 70 million disability-adjusted life years. Over the past six decades, China has made remarkable achievements in morbidity control, but disability and mortality control remains much to desire; thus, advanced schistosomiasis is a growing problem when on the road to schistosomiasis elimination. Since 2005, China has initiated a national treatment and assistance program to advanced patients, aiming to improve patients' symptoms and quality of life. Here, we conducted a two-phase study to evaluate the program's implementation and effect on advanced patients from 2009 to 2014 in Jiangxi Province, China. A total of 6425 advanced schistosomiasis cases were included in this study. For those having been treated and assisted (90.7 %), the cure or improvement rate was over 99.9 %, with 668 (11.5 %) cases having reached clinical cure and 5152 (88.4 %) cases' condition having improved, which can be partially reflected in the significant decline of the proportion of hepatomegaly (splenomegaly), the degree of liver fibrosis, ascites-related indicators (abdominal girth and frequency of shifting dullness), and portal hypertension-related indices (inner diameter of portal vein and frequency of subcutaneous varicose vein of abdominal wall). Besides, it was estimated to have saved 2004 years of life lost at total. Therefore, the government should continue support and increase input of treatment and assistance program so that this project can reach more patients, leading to consolidation of achievements of schistosomiasis control and contribution to schistosomiasis elimination.

Recombinant T2 RNase protein of Schistosoma japonicum inhibits expression of α-SMA in LX-2 cells.

Recombinant T2 RNase glycoprotein, which showed a certain degree of homology to Omega-1 from Schistosoma mansoni eggs, was expressed in adult worms of Schistosoma japonicum, but not in eggs of S. japonicum. The direct biological role of the recombinant T2 RNase protein in activation of hepatic stellate cells (HSCs) remains unknown. In the present study, the immortalized human HSC line (LX-2 cells) was treated with the recombinant T2 RNase protein at indicated concentrations for various time points in vitro. The expression levels of α-smooth muscle actin (α-SMA) and Smad4 were detected by Western blot. The results showed that the recombinant T2 RNase protein significantly diminished the expression levels of α-SMA and Smad4 in LX-2 cells. The upregulated expression levels of α-SMA and Smad4 by TGF-ß1 in LX-2 cells were both suppressed by the recombinant T2 RNase protein. These data suggest that the recombinant T2 RNase protein may be a potential target of therapeutic strategy for the treatment of hepatic fibrosis.

Schistosoma japonicum in Samar, the Philippines: infection in dogs and rats as a possible risk factor for human infection.

The role that animals play in the transmission of Schistosoma japonicum to humans in the Philippines remains uncertain and prior studies have not included several species, adjustment for misclassification error and clustering, or used a cohort design. A cohort study of 2468 people providing stool samples at 12 months following praziquantel treatment in 50 villages of Western Samar, the Philippines, was conducted. Stool samples from dogs, cats, rats, and water buffaloes were collected at baseline (2003-2004) and follow-up (2005). Latent-class hierarchical Bayesian log-binomial models adjusting for misclassification errors in diagnostic tests were used. The village-level baseline and follow-up prevalences of cat, dog, and rat S. japonicum infection were associated with the 12-month cumulative incidence of human S. japonicum infection, with similar magnitude and precision of effect, but correlation between infection levels made it difficult to divide their respective effects. The cumulative incidence ratios associated with a 1% increase in the prevalence of infection in dogs at baseline and in rats at follow-up were 1·04 [95% Bayesian credible interval (BCI) 1·02-1·07] and 1·02 (95% BCI 1·01-1·04), respectively, when both species were entered in the model. Dogs appear to play a role in human schistosomiasis infection while rats could be used as schistosomiasis sentinels.

Significance of higher drug concentration in erythrocytes of mice infected with Schistosoma japonicum and treated orally with mefloquine at single doses.

The purpose of the present study is to understand the pharmacokinetic feature of mefloquine measured by erythrocytes and plasma in Schistosoma japonicum (S. j.)-infected mice and non-infected mice after oral administration of the drug at single doses. A high-performance liquid chromatography (HPLC) method was used to measure the plasma and erythrocyte concentrations of mefloquine at varying intervals posttreatment. Our results demonstrated that in non-infected mice treated orally with mefloquine at an ineffective dose of 50 mg/kg or effective dose of 200 mg/kg for 2-72 h, the erythrocyte-to-plasma ratios of mefloquine were 5.8-11.2 or 2-14.2. On the other hand, in S. j.-infected mice treated with the same single doses of the drug, the erythrocyte and plasma drug concentration ratios were 3.1-4.6 or 2.9-8.5, manifesting that either in infected mice or in non-infected mice that received oral mefloquine resulted in higher concentration of mefloquine in erythrocytes than that in plasma. Unexpectedly, under oral administration of mefloquine at a higher single dose of 200 mg/kg, the pharmacokinetic parameter C max values for plasma from S. j.-infected and non-infected mice were 1.6 ± 0.3 and 2.0 ± 0.4 µg/mL, respectively, which were below the determined in vitro LC50 (50 % lethal concentration) value of 4.93 µg/mL. Therefore, the plasma concentration of mefloquine may display a little effect against schistosomes during the treatment. Although the values of T 1/2 and AUC0-∞ for erythrocytes were significantly longer and higher in infected mice than those of corresponding non-infect mice that received the same single mefloqine dose of 50 mg/kg, the C max value was only 2.6 ± 0.4 µg/mL lower than the determined in vitro LC50, which may explain why this low single dose is ineffective against schistosomes in vivo. After administration of higher mefloquine dose of 200 mg/kg, the C max value for erythrocytes in infected mice was 30 % (7.4 ± 0.7 versus 10.7 ± 2.7 µg/mL) lower than that in the corresponding non-infected mice, but its level was above the determined in vitro LC95 (95 % lethal concentration) value of 6.12 µg/mL. Meanwhile, longer T 1/2 value of 159.2 ± 129.3 h in infected mice led to significant increase in AUC0-∞ value (1969.3 ± 1057.7 vs 486.4 ± 53.0 µg/mL·h), relative to corresponding non-infected mice. In addition, the mean residence time (MRT0-∞) in infected mice was also significantly longer than that in non-infected mice. All these results may beneficial for the treatment. According to the results, we suggest that higher ratios of mefloquine concentration in erythrocytes to plasma may offer a way to transport mefloquine to the worm gut through ingestion of erythrocytes by the worms, where the gut is the site for displaying the effect by mefloquine.

Transdermal praziquantel administration attenuates hepatic granulomatosis in mice infected with Schistosoma japonicum.

Liver granuloma is a major pathogenic factor responsible for schistosomiasis, and no effective drugs or therapy methods to treat it have been found so far. Praziquantel (PZQ) has shown some anti-schistosomal effect, but little information is available about the effect of PZQ-prolonged administration on granuloma formation around schistosome eggs. Herein, we investigated the effect of PZQ on hepatic granuloma formation by treating the mice infected with Schistosoma japonicum using a long-term PZQ transdermal delivery. The results showed that the mean area of granulomas in the group treated with PZQ transdermal agent was (175.47 ± 116.73) × 10(3) µm(2) at the 49th day postinfection and (71.96 ± 45.99) × 10(3) µm(2) at the 56th day, while that in the control group was (304.51 ± 140.55) × 10(3) µm(2) and (526.44 ± 268.06) × 10(3) µm(2), respectively. The content of hydroxyproline in the livers of mice approached to the normal level on the 154th day in the treatment group, but it continued to increase from the 28th day to the 154th day after infection in the control group and nontreatment group. The ALT activity in serum of mice in the treatment group was also significantly lower than that in the control group (*P ≤ 0.05). Our results suggest that the long-term PZQ transdermal delivery is critical in the therapeutic approach to control the progress of hepatic schistosomiasis induced by egg granulomas.