Anti-Glioma Effects of Ligustilide or n-Butylphthalide on Their Own and the Synergistic Effects with Temozolomide via PI3K/Akt Signaling Pathway.

Background: Ligustilide (LIG) and n-butylphthalide (NBP) have neuroprotective effects in cerebral ischemia; however, their roles in gliomas are not well-known.This study aimed to explore the anti-glioma effects of LIG and NBP individually and the synergistic effects of temozolomide (TMZ) via the PI3K/Akt Signaling Pathway. Materials and Methods: Cytotoxicity of LIG and NBP alone and in combination with TMZ in U251 cells was determined using the CCk-8. The effect of compounds alone or in combination on cell migration was detected using the wound healing assay, and the invasion was evaluated by transwell assays, respectively. Cell apoptosis was quantified by flow cytometry and the changed expressions of proteins were detected by Western blotting. Results: The results showed that LIG and NBP significantly inhibited the growth of U251 cells at concentrations of 4-10 µg/mL and 1.5-6 µg/mL in a dose-dependent manner (p<0.05, p<0.01). The combination of 20 µg/mL TMZ with LIG in the concentration range of 4-10 µg/mL or with NBP of 0.5-6 µg/mlachieved synergistic effect towardsU251 cells. LIG and NBP, alone or in combination with TMZ, markedly inhibited cell invasion (p< 0.001) and enhanced apoptosis (p< 0.05). The combination of TMZ with LIG or NBP markedly inhibited cell migration (p< 0.001). Western blot analysis showed that LIG, NBP, and TMZ, alone and in combination, significantly decreased the expression of Bcl-2, p-PI3K, and p-Akt, and increased the expression of Bax. Conclusion: Both LIG and NBP exert anti-glioma effects on their own through the PI3K/Akt pathway and enhance TMZ-mediated anti-glioma efficiency via the same pathway.

Confined Concrete in Fiber-Reinforced Polymer Partially Wrapped Square Columns: Axial Compressive Behavior and Strain Distributions by a Particle Image Velocimetry Sensing Technique.

Strengthening existing reinforced concrete (RC) columns using a partial wrapping strengthening technique (PWST) by fiber-reinforced polymer (FRP) strips has been widely implemented. However, compared with the confinement mechanism of confined concrete in columns strengthened with the FRP full wrapping strengthening technique (FWST), the confinement mechanism of confined concrete in FRP partially wrapped columns is less understood. This paper presents the results of an experimental investigation into the behavior of confined concrete in FRP partially wrapped square columns under axial compression. The effects of FRP strip width and thickness on stress⁻strain behavior were thoroughly investigated. The novel particle image velocimetry (PIV) non-contact strain sensing technique was adopted to measure the strain in the specimens. Results show that the axial strains as well as the hoop strains are generally larger at the mid-plane of adjacent FRP strips than those at the mid-plane of each FRP strip, and considerable variation in hoop strains along the height of the specimens was observed. Comparisons between the experimental results and predictions by existing design-oriented stress⁻strain models were carried out to examine the accuracy of the models. A new design-oriented stress⁻strain model is proposed for confined concrete in FRP partially wrapped square columns and the comparisons between laboratory results and predictions from the proposed model show that the proposed model is superior to the existing models.

Pharmacological and immunological effects of praziquantel against Schistosoma japonicum: a scoping review of experimental studies.

BACKGROUND: Chemotherapy for schistosomiasis has been around for 100 years. During the past century, great efforts have been made to develop new antischistosomal drugs from antimonials to nonantimonials, and some of these have been used extensively in clinical treatment. With the exception of a few drugs, such as oxamniquine and metrifonate, most of the antischistosomals developed in the pre-praziquantel period have variable limitations with respect to safety and efficacy. Although oxamniquine and metrifonate have been used for schistosomiasis control, they are only effective against Schistosoma mansoni and S. haematobium, respectively. Currently, praziquantel is the only drug used for treatment of all five species of human schistosomes. In this review, the pharmacological and immunological effects of praziquantel against S. japonicum are summarized and discussed. MAIN TEXT: From the end of the 1970s until the 2000s, scientists have conducted a series of experimental studies on the effects of praziquantel against S. japonicum. These have included examining its unique pharmacological action on schistosomes, the characteristics in susceptibility of the different developmental stages of schistosomes to the drug, the relationship between plasma concentration of the drug and efficacy, the impact of host factors on cidal action of the drug, prevention and early treatment of schistosomal infection, as well as praziquantel-resistant schistosomiasis. CONCLUSION: The effects of praziquantel against S. japonicum, as elucidated by the experimental studies that are reviewed in this paper, may have some reference significance for the development of new antischistosomals.

Schistosoma hemozoin and its possible roles.

More than 95years ago Schistosoma pigment had been deemed as a degradation product of haemoglobin. Until the 1950s, scientists initiated to pay attention to understand the hematophagous habit of schistosomes, and to study the degradation of haemoglobin as well as the formation of hemozoin inside the gut of the worms. For a long time, the formation of hemozoin in both Plasmodium and in Schistosoma was considered to be the major route of heme detoxification, and hemozoin served a role in waste disposal. At the beginning of this century, the chemical structure of Schistosoma pigment was confirmed to be identical to that of malarial pigment (hemozoin) and its synthetic analogue, ß-hematin. Since then, studies on Schistosoma hemozoin have been investigated by some workers and the results showed that Schistosoma hemozoin may play important roles in pathogenicity, immune modulation, iron supply for egg formation, and interaction with some anti-schistosomal drugs. In this review, we briefly review and discuss the hematophagous habit of schistosomes, degradation of haemoglobin, formation of hemozoin in the worm gut, and possible roles of hemozoin.

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.

Efficacy and safety of praziquantel, tribendimidine and mebendazole in patients with co-infection of Clonorchis sinensis and other helminths.

BACKGROUND: Both tribendimidine and mebendazole are broad-spectrum drugs for anti-intestinal nematodes. We aim to assess the efficacy and safety of tribendimidine and mebendazole in patients with co-infection of Clonorchis sinensis and other helminths. METHOD: We performed a randomized open-label trial in Qiyang, People's Republic of China. Eligible participants were randomly assigned to one of four groups: (i) a single dose of 400 mg tribendimidine, (ii) 200 mg tribendimidine twice daily, (iii) 75 mg/kg praziquantel divided in four doses within 2 days, and (iv) a single dose of 400 mg mebendazole. Cure rates and egg reduction rates were assessed, and adverse events were monitored after treatments. Uncured patients accepted the second treatment with the same drugs after the first treatment. RESULTS: 156 patients were eligible for the study. Results from the first treatment showed that the cure rates of single-dose tribendimidine and praziquantel against C. sinensis were 50% and 56.8%, respectively; the single-dose tribendimidine achieved the cure rate of 77.8% in the treatment for hookworm, which was significantly higher than that of praziquantel; Low cure rates were obtained in the treatment of single-dose tribendimidine against Ascaris lumbricoides and Trichuris trichiura (28.6% and 23.1%). Results of the second treatment illustrated the cure rates of tribendimidine and praziquantel against C. sinensis were 78.1% and 75%, respectively. Most adverse events were mild and transient. Adverse events caused by tribendimidine were significantly less than praziquantel. CONCLUSION: Single-dose tribendimidine showed similar efficacy against C. sinensis as praziquantel with less adverse events, and achieved significantly higher cure rate in the treatment for hookworm than those of praziquantel and mebendazole. Low cure rates, which were still higher than other drugs, were obtained in the treatment of single-dose tribendimidine against Ascaris lumbricoides and Trichuris trichiura. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN55086560.

Effect of ozonide OZ418 against Schistosoma japonicum harbored in mice.

The in vitro and in vivo efficacies of ozonide carboxylic acid OZ418 against Schistosoma japonicum were investigated. For in vitro experiments, juvenile (14-day-old) and adult schistosomes were collected from mice infected with 80-100 S. japonicum cercariae for 14 and 35 days post-infection and the worms were maintained in Roswell Park Memorial Institute (RPMI) 1640 supplemented by 10% calf serum. Against 35-day-old adult S. japonicum, OZ418 resulted in weakened worm motor activity, injury to the worm body, emergence of vacuoles along the worm surface, and death. A similar outcome was seen in 14-day-old juvenile S. japonicum exposed to OZ418. Ineffective concentrations (1, 5, and 10 µg/mL) of OZ418 also interacted with hemin to significantly increase the killing effect against adult schistosomes. The LC50 value of OZ418 against juvenile (14-day-old) and adult schistosomes were identical--16.2 µg/mL, whereas the corresponding LC95 values were 30.7 and 22.7 µg/mL, respectively. Treatment of adult and juvenile (14-day-old) S. japonicum-infected mice with single 200-400-mg/kg oral doses of OZ418 produced total worm burden reductions of 68.5-84.1 and 37.5-50.9%, respectively. Further study showed that in mice infected with various stages of schistosomes and treated with a single oral OZ418 400 mg/kg, poor efficacy was seen in the 3-h-old juvenile worm group, while 14-day-old and 21-day-old juvenile worm groups exhibited less efficacy with total worm burden reductions of 42.6-52.4%. On the other hand, similar and higher total worm burden reductions (64.2-76.0%) were seen in the 7-day-old juvenile worm group and 28-day-old as well as 35-day-old adult worm groups. Furthermore, the mean worm burden reductions of the 7-day-old juvenile worm group and 35-day-old adult worm group were statistically significantly higher than that of the 14-day-old or 21-day-old juvenile worm group (P < 0.01 or <0.05). These data suggest that OZ418 has promising efficacy against 7-day-old juvenile and adult S. japonicum.

Mefloquine in combination with hemin causes severe damage to adult Schistosoma japonicum in vitro.

In order to explore the interaction of mefloquine with hemin against adult Schistosoma japonicum in vitro, the 50% and 95% lethal concentration (LC50 and LC95) of mefloquine and hemin against schistosomes, some factors, such as other iron providing agents, iron chelaters, zinc protoporphyrin-IX, and biological relevant reductants, that might impact on antischistosomal activity induced by interaction of mefloquine with hemin, and preliminary analysis of chemical interaction of both compounds were undertaken. The LC50 and LC95 of mefloquine and hemin alone against schistosomes were determined to be 6.5µg/ml and 7.8µg/ml as well as 232µg/ml and 355µg/ml, respectively. The LC50 and LC95 of mefloquine in the presence of hemin 100µg/ml was 0.24µg/ml and 0.59µg/ml, respectively. On the other hand the LC50 and LC95 of hemin in the presence of mefloquine 1µg/ml was 23.2µg/ml and 77.2µg/ml, respectively. Meanwhile, mefloquine/hemin combinations showed potential synergistic effects against adult S. japonicum, with combination index (CI) values <1. Apart from hemin, zinc protoporphyrin-IX, and other iron providing agents such as ferrous sulfate and ferriammonium sulfate combined with mefloquine exhibited no toxic effect against schistosomes. On the other hand, addition of iron chelators (deferiprone, desferrioxamine mesylate, or 2,2'-bipyridine) to the medium containing mefloquine-hemin resulted in no protective effect on the worms. Furthermore, biological reductants like glutathione, vitamine C or cysteine showed no apparent worm protection effect from toxic mefloquine-hemin even at higher concentrations (242.3-614.6µg/ml, i.e., 6.4-17.8-fold higher than the concentration of hemin). Chemical interaction of mefloquine with hemin was studied in 40% DMSO-Tris buffer solution. Both UV-Vis spectrum and mass spectrum demonstrated the strong interaction of mefloquine with hemin, which resulted in a reduction of hemin color and emergence of an adduct formed by mefloquine and hemin. The results confirm that mefloquine combined with hemin exhibits potential synergistic effect against adult S. japonicum in vitro.

Mefloquine, a new type of compound against schistosomes and other helminthes in experimental studies.

Up to date, schistosomiasis is still prevalent worldwide. It is estimated that more than 200 million individuals are infected, and 120 million suffer from clinical morbidity. Facing such huge cases of schistosomiasis, only heavy reliance on a single praziquantel for schistosomiasis control does not adapt and may promote the selection and spread of drug-resistant parasites. Therefore, it is an urgent need to develop the new antischistosomal drug. In 2008-2009, the antimalarial drug mefloquine, an arylaminoalcohol compound, has been found to be effective against schistosomes. According to the experimental studies, the deepest impression on the antischistosomal properties of mefloquine can be summarized as following points: (1) single dose of mefloquine possesses potential effect against three major species of schistosomes (Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum) infecting humans; (2) the drug displays similar effects against developing stages of juvenile and adult schistosomes, which are superior to that of artemisinins and praziquantel; (3) in vitro mefloquine exerts direct killing effect on juvenile and adult schistosomes, while in vivo, the efficacy of the drug is independent to host immune response, (4) mefloquine causes extensive and severe morphological, histopathological, and ultrastructural damage to adult and juvenile schistosomes, particularly, the worm tegument, musculature, gut, and vitelline glands of female worms are the key sites attacked by the drug; (5) combined treatment with mefloquine and praziquantel, or artemisinins shows synergistic effect against schistosome in experimental therapy,while in initially clinical trial, mefloquine in combination with artesunate also exhibits higher cure rates against schistosomiasis hematobia and schistosomiasis mansoni, and (6) several mefloquine-related arylmethanols exhibit potential effect against schistosomes in vivo, which is a useful clue helpful for development of new antischistosomal compound. In the present review, we have summarized the major results published in recent years, and the significance as well as the prospect for the future study of mefloquine have been discussed briefly.

Advances with the Chinese anthelminthic drug tribendimidine in clinical trials and laboratory investigations.

The anthelminthic drug tribendimidine has been approved by Chinese authorities for human use in 2004, and a first comprehensive review was published in Acta Tropica in 2005. Here, we summarise further advances made through additional clinical trials and laboratory investigations. Two phase IV trials have been conducted in the People's Republic of China, the first one enrolling 1292 adolescents and adults aged 15-70 years and the second one conducted with 899 children aged 4-14 years who were infected with one or multiple species of soil-transmitted helminths. Oral tribendimidine (single 400mg enteric-coated tablet given to adolescents/adults and 200mg to children) showed high cure rates against Ascaris lumbricoides (90.1-95.0%) and moderate-to-high cure rates against hookworm (82.0-88.4%). Another trial done in school-aged children using a rigorous diagnostic approach found a cure rate against hookworm of 76.5%. A single oral dose of tribendimidine showed only low cure rates against Trichuris trichiura (23.9-36.8%) confirming previous results. Tribendimidine administered to children infected with Enterobius vermicularis (two doses of 200mg each on consecutive days) resulted in a high cure rate (97.1%). Importantly, a series of randomised, exploratory trials revealed that tribendimidine shows interesting activity against the liver flukes Opisthorchis viverrini and Clonorchis sinensis, the tapeworm Taenia spp. and the threadworm Strongyloides stercoralis with respective cure rates of 70.0%, 40.0%, 53.3% and 36.4%. Pharmacokinetic studies in healthy Chinese volunteers indicated that after oral administration of tribendimidine, no parent drug was detected in plasma, but its primary metabolite, p-(1-dimethylamino ethylimino) aniline (aminoamidine, deacylated amidantel) (dADT), was found in plasma. dADT is then further metabolised to acetylated dADT (AdADT). dADT exhibits activity against several species of hookworm and C. sinensis in experimental studies, similar to that of tribendimidine. First studies elucidating the mechanism of action suggested that tribendimidine is an L-type nicotinic acetylcholine receptor agonist. Additional experimental studies revealed that the anti-parasite spectrum of tribendimidine is very broad. Indeed, to date, activity has been documented against 20 different nematode, trematode and cestode species. Taken together, tribendimidine warrants further scientific inquiry, including more comprehensive toxicity appraisals, mechanism of action studies and clinical investigation as it holds promise as a broad spectrum anthelminthics.

[Preliminary observation on the effect of mefloquine against egg granuloma formation in the liver of mice infected with Schistosoma japonicum].

OBJECTIVE: To explore whether mefloquine possesses the effect on granuloma formation induced by Schistosoma japonicum eggs. METHODS: Seventeen out of twenty-eight mice infected with 20 S. japonicum cercariae for 35 days were treated orally with mefloquine at a single dose of 200 mg/kg, and groups of 2-3 mice were sacrificed at various intervals post-treatment. The livers removed from each group of mice were fixed in 10% formaldehyde. While the remained 11 untreated mice divided into 6 groups (1-2 mice per group) were sacrificed at the same time periods as groups of mice treated with mefloquine, and their livers served as untreated corresponding controls. The granulomas with single egg in the center were counted and their diameters were measured using an ocular micrometer. The liver tissue sections were stained with hematoxylin and eosin (HE), Foot's or Mallory's methods for observation on histopathological alteration of egg granulomas, and on the appearance of reticular and collagen fibers within the granulomas. RESULTS: After infected mice were treated with mefloquine for 3, 7, 14, 21, 28 and 35 days, i.e., 38, 42, 49, 56, 63, and 70 days post-infection, the mean diameters of granuloma with single egg measured in the liver tissues section were (161 +/- 19), (175 +/- 13), (195 +/- 9), (171 +/- 40), (180 +/- 13), and (145 +/- 25) microm, respectively, and each of them was significantly lower than that of its corresponding control group of (189 +/- 18), (197 +/- 11), (211 +/- 12), (208 +/- 19), (203 +/- 16), and (207 +/- 36) microm (P < 0.01 or P < 0.05). Histopathological observation showed that in mice treated with mefloquine, the eosinophil-predominant inflammatory cells around the egg granuloma were sustained to 14-21 d post treatment (49-56 d post infection), which was significantly different from the corresponding control groups that all the eggs were surrounded by fibroblasts at 42 d post infection. Up to 28-35 d post treatment (63-70 d post infection), the boundary of egg granulomas distributed in the liver tissues of mefloquine treated groups was nearer in comparison to the corresponding control groups. Further observation on the reticular and collagen fibers within the egg granulomas by using specially staining methods demonstrated that in groups of mice treated with mefloquine for 2 weeks, the emergence and amount of the two kinds of fibers were delayed and less in comparison with corresponding control groups. After infected mice treated with mefloquine for 21 d (56 d post infection), the amount of the two kinds of fibers revealed in some egg granulomas was similar to the corresponding control group, but no further increase in the amount of the fibers, and seldom spread over the boundary of egg granuloma were seen 28 d and 35 d after treatment (63 d and 60 d post infection). While in corresponding control groups, the two kinds of fibers increased continuously with time post infection to become thick, and spread over the boundary of granuloma to further interconnect with the fibers stretched from the adjacent granuloma, and separate the liver tissue to form the grid-like structure. CONCLUSION: Preliminary observation demonstrates that mefloquine possesses suppressive effect on granuloma formation induced by S. japonicum eggs.

[Comparative observation on inhibition of hemozoin formation and their in vitro and in vivo anti-schistosome activity displayed by 7 antimalarial drugs].

OBJECTIVE: To observe and compare the inhibition of hemozoin formation and the in vitro as well as in vivo antischistosomal activity induced by seven antimalarial drugs. METHODS: Inhibition of hemozoin formation displayed by chloroquine phosphate, quinine hydrochloride, quinidine, mefloquine hydrochloride, pyronaridine phosphate and lumefantrine at 25 micromol/L, and artemether at 100 micromol/L was performed by assay of inhibition of beta-hematin formation in 1 mol/L sodium acetate buffers containing hematin with various pH of 4.0, 4.2, 4.4, 4.6, 4.8, and 5.0. In in vitro antischistosomal study, the medium of RPMI 1640 supplemented by 10% calf serum was used to maintain the adult Schistosoma japonicum, and the 50% and 95% lethal concentrations (LC50 and LC95) to kill the adult worms of each drug were then determined. Meanwhile, the interaction of quinine, pyronaridine and chloroquine combined with hemin against adult schistosomes was also undertaken. As to in vivo test, the efficacy of seven antimalarial drugs administered orally or intraperitoneally to mice infected with adult schistosomes was observed. RESULTS: In the acidic acetate-hematin solution, 25 micromol/L pyronaridine showed significant inhibition of beta-hematin formation at pH 4.4-5.0 with inhibition rates of 81.3%-97.0%. At pH 4.6, the inhibition rates of beta-hematin formation in acetate-hematin solution induced by mefloquine, chloroquine or quinine at concentration of 25 beta mol/L were 79.7%, 72.8% or 65.8%, respectively, and the beta-hematin formation was continually inhibited by these 3 antimalarial drugs at pH 4.8 and 5.0 with inhibition rates of 83.1%-90.6%, 41.9%-49.0% or 53.2-62.0%. The inhibition rates of beta-hematin formation at pH 4.6 and 4.8-5.0 induced by lumefantrine 25 micromol/L were 74.3% and 40.4%-40.5%, respectively. While under the same concentration of quinidine, 53.4% and 50.9% inhibition rates of beta-hematin formation were observed at pH 4.8 and 5.0. As to artemether, higher concentration of 100 micromol/L only showed light inhibition of beta-hematin formation at pH 4.4-4.8 with inhibition rates of 16.6%-25.0%. As regard to in vitro test, the LC50 and LC95 of mefloquine, pyronaridine, quinine and quinidine were 4.93 and 6.123 microg/ml, 37.278 and 75.703 microg/ml, 93.688 and 134.578 microg/ml, as well as 101.534 and 129.957 microg/ml, respectively. When adult schistosomes were exposed to the medium containing chloroquine, lumefantrine or artemether at higher concentrations of 100 or 120 microg/ml for 72 h, no or only individual worms died. Hence the LC50 and LC95 of these 3 drugs could not be determined. In other in vitro test, adult schistosomes exposed to quinine 50 micromol/L (20 microg/ml) in combination with 153.4 micromol/L (100 microg/ml) hemin, all worms died within 72 h post incubation. While the worms exposed to 50 micromol/L (26 microg/ml) chloroquine combined with the same concentration of hemin, only 18.8%(3/16) of worm died at 72 h post exposure. Unexpectedly, in schistosomes exposed to pyronaridine at a toxic concentrations of 50 micromol/L (46 microg/ml) in combination with 153.4 mol/L (100 microg/ml) hemin for 72 h, all of the worms were protected from the toxic action induced by pyronaridine, which revealed in normal motor activity and appearance of morphology in majority of the worms. In in vivo test, mice infected with adult schistosomes were treated orally with chloroquine, pyronaridine or lumefantrine at a daily dose of 400 mg/kg for 3 days, or intraperitoneally with chloroquine or pyronaridine at a daily dose of 100 mg/kg for 2 or 3 days, no apparent efficacy was seen. When mefloquine, quinine, quinidine or artemether were administered orally to infected mice at a single dose of 400 mg/kg or 200 mg/kg (mefloquine), all groups of mice treated showed moderate or higher efficacy with worm burden reductions of 61.1%-98.1%. CONCLUSION: Among the seven antimalarial drugs tested, their inhibitions of hemozoin (beta-hematin) exhibit no definite correlation to their in vitro and in vivo antischistosomal activity. Quinine in combination with hemin shows synergistic effect against schistosomes in vitro. While antagonist effect is observed in pyronaridine combined with hemin.

Ultrastructural alterations of adult Schistosoma japonicum harbored in mice treated with a single oral dose of OZ78.

OBJECTIVE: To observe the ultrastructural alterations of adult Schistosoma japonicum induced by synthetic trioxolane OZ78. METHODS: Eight out of ten mice infected with 40-60 S. japonicum cercariae for 35 d were treated orally with OZ78 at a single dose of 400 mg/kg. Four groups of two mice were killed at 24 h, 3 d, 7 d, and 14 d post treatment, and schistosomes were recovered by perfusion technique, fixed, and examined by transmission electron microscopy. Schistosomes obtained from the remaining two untreated mice served as control. RESULTS: After infected mice were treated with OZ78 for 24 h, the prominent alterations in tegument of both male and female worms were observed, which revealed in flattened surface due to swelling of cytoplasmic processes, irregular expansion in distal end of cytoplasmic processes accompanied by decrease in rod-like and discoid-like secretory bodies, focal lysis of tegumental matrix; fusion of some cytoplasmic processes to form a large piece, disruption or disappearance of basal membrane, and destruction of internal structures in sensory organelles. In the subtegument, no or slight swelling and focal lysis of muscle bundles were seen, while the syncytium beneath the muscle showed enlargement of nucleus with indistinction of partial nuclear membrane, formation of small vacuoles due to focal lysis of chromatin, and emergence of degenerated mitochondria in perinuclear cytoplasm. As to parenchymal tissues, the major alterations included degeneration of mitochondria, formation of some small vacuoles and myelin-like structures. In gut epithelial cells, the prominent alterations were irregular enlargement of nucleus with light lysis of nucleoli and fusion of partial bi-layer nuclear membrane, degeneration of mitochondria in cytoplasm and collapse of microvilli. At this time point, in the vitelline cells of female worms, the most significant alteration was the collapse of many vitelline droplets, which led to release of the vitelline balls, followed by their lysis and fusion. Three to 7 d post treatment, the damage to the worms aggravated either in extent or in severity along with time. The significant damages to male and female worms were fusion of cytoplasmic processes, peeling or collapse of damaged cytoplasmic processes resulting in exposure of muscle bundles, severe destruction of sensory organelles and syncytium, focal or extensive swelling and lysis of muscle bundles, emergence of some larger piece of degenerated parenchymal tissues and severe damage to the gut epithelial cell. While in the vitelline cells of female worms, decrease in the number of vitelline droplet, focal lysis of nucleus and extensive lysis of parenchymal tissues among the vitelline cells were also observed. Fourteen days post OZ78 dosing, male and female worms which survived the treatment showed some renovation in damaged tegument and subtegument, while most gut epithelial cells and vitelline cells still revealed in prominent injury. CONCLUSION: The results demonstrate that OZ78 possesses an extensive damage to the ultrastructure in tegument and subtegument tissues including syncytium, parenchymal tissues, gut epithelial cells, and vitelline cells of adult S. japonicum.

[Study progress on mefloquine against schistosomes and other helminths].

In recent years, antimalarial drug mefloquine, an amino alcohol compound, has been found to exhibit potential effect against schistosomes. The feature of antischistosomal properties of mefloquine is that the drug possesses similar killing effect against various development stages of juvenile and adult schistosomes. This paper summarizes the recent three years' progress in experimental studies of mefloquine against schistosomes and other helminthes.

[Research on needle-acupointomics].

The concept of needle-acupointomics should be clarified initially in order to discuss the relative researches. The comprehension can be deepened through the aspects of researching methods, content and goals. Proper researching model and analysis method should be selected so as to bring the advantages of the ancient acupuncture literatures, case records and clinical experiences of famous physicians into full play. Only in this way can the domestic needle acupointomics studies achieve a breakthrough.

Ultrastructural alterations of juvenile Schistosoma japonicum harbored in mice following mefloquine administration.

The aim of the present study was to assess the ultrastructural alterations of juvenile Schistosoma japonicum induced by mefloquine. Mice infected with 14-day-old S. japonicum were treated orally with mefloquine at a single dose of 400 mg/kg. Between 8 h and 7 days after treatment, groups of two mice were sacrificed, and schistosomula were recovered for transmission electron microscopic observations. Ultrastructural damage was seen in the tegument, subtegumental musculature, parenchymal tissues, and gut epithelial cell. It was already prominent 8 h after drug administration and increased in severity rapidly to reach a peak 3 days post-treatment. Tegumental alterations were characterized by emergence of irregular and elongated cytoplasmic processes, which further fused together accompanied by indistinction of matrix and roughness of external plasma membrane. Meanwhile, in the subtegument, damage to the syncytium, swelling, and lysis of muscle bundles and parenchymal tissues were universal, which further aggravated the lesion on the tegument, followed by collapse or disintegration of damaged tegument to form numerous fragment or debris of cytoplasmic process detached from the worm surface. Severe damage to the gut epithelial cell was also observed 8 h post-mefloquine treatment, which included focal lysis of cytoplasm accompanied by formation of vacuoles and degeneration of mitochondria, emergence of enlarged and contracted nucleus with indistinct or focal disrupted nuclear membrane, and decrease in microvilli. All these alterations further increased in severity and reached the peak 3 days post-treatment. The findings of our study indicate that mefloquine exhibits a fast and potent ability to cause extensive ultrastructural damage to juvenile S. japonicum, which correlates with its high efficacy against juvenile schistosomes.

Further studies on mefloquine and praziquantel alone or interaction of both drugs against Schistosoma japonicum in vitro.

The aim of the present study is to further understand and analyze the interaction of mefloquine with praziquantel against adult Schistosoma japonicum in vitro. Mice infected with S. japonicum cercariae for 35-37 days were sacrificed, and adult schistosomes were collected by perfusion. Schistosomes were placed to each of 12 wells of a Falcon plate and maintained in RPMI 1640 supplemented by 10% calf serum. For determination of 50% and 95% lethal concentration (LC50 and LC95) of the two drugs in vitro, schistosomes were exposed to mefloquine at concentrations of 1, 2, 3, 4, 5, 6, 7, and 10 µg/mL or praziquantel at concentrations of 0.001, 0.01, 0.05, 0.1, 0.2, 0.5, 1, 10, and 30 µg/mL. The plate was incubated at 37°C in 95% air + 5% CO2 for 72 h. According to the half-life of oral mefloquine and praziquantel in mice, mefloquine combined with praziquantel simultaneously, mefloquine administered within 1 h after praziquantel and praziquantel administered within 17 h after mefloquine were used to evaluate the effect of mefloquine in combination with praziquantel against S. japonicum in vitro. The results showed that the LC50 and LC95 of mefloquine calculated by the Bliss method were 6.17 µg/mL (95% confidence limits, 5.84-6.517 µg/mL) and 8.703 µg/mL (95% confidence limits, 7.632-9.797 µg/mL), respectively. As to praziquantel, no worm death was seen when schistosomes were exposed to praziquantel at concentrations of 0.005-0.2 µg/mL for 72 h. While in the worms exposed to praziquantel 1, 10, and 30 µg/mL, strong spasmodic contractions of the worm body and vesiculation along the worm surface were observed, but 48-75% of the schistosomes survived the exposure in 72-h incubation. Meanwhile, the number of dead worms that emerged in each group was not proportion to the increasing concentrations. Therefore, it is not appropriate to calculate the LC50 and LC95 of praziquantel. For evaluation of the interaction with the two drugs, praziquantel 0.1 or 0.2 µg/mL, which may induce moderate or strong spasmodic contractions of the worm body and vesiculation along the worm surface, was combined with mefloquine 5, 6, or 7 µg/mL. It was found that when mefloquine combined with praziquantel simultaneously or administered 1 h after addition of praziquantel, the spasmodic contraction of the male worm body was antagonized by mefloquine in various degrees according to the concentrations of mefloquine used. Meanwhile, praziquantel-induced weakened motor activity could be reversed by mefloquine. In female worms, morphological alterations and stimulated motor activity induced by mefloquine still developed. Interestingly, using these two regimens to combine mefloquine with praziquantel resulted in no impact or a decrease in worm mortality. On the other hand, praziquantel 0.2 µg/mL administered within 17 h after mefloquine 5 or 6 µg/mL promoted the damage to the tegument of the worms, which led to enhance the worm mortality compared with that of worms exposed to mefloquine alone. The results indicate that in vitro higher concentrations of praziquantel administered within 17 h after mefloquine may increase the effect against adult schistosomes, while praziquantel combined with mefloquine simultaneously or administered 1 h before addition of mefloquine exhibits no impact or decrease in the effect against schistosomes.

Histopathological changes of juvenile Schistosoma japonicum harbored in mice treated orally with mefloquine at a smaller single dose.

The histopathological changes of 14-day-old Schistosoma japonicum induced by a smaller single dose of mefloquine have been studied. Twenty-three mice infected with 60-80 S. japonicum cercariae for 14 days were treated orally with mefloquine at a single dose of 200 mg/kg (free base), and groups of three mice were killed at various intervals posttreatment. The liver of each mouse was removed, fixed and processed routinely, and examined by light microscopy. Eight hours posttreatment, 38.2% and 39.8% of schistosomulum sections were classified as degenerated and dead, respectively. The degenerated schistosomula revealed in high dilatation of gut with disruption of gut mucosa, swelling of the worm body accompanied by looseness or extensive lysis of parenchymal tissues, and focal swelling or peeling of tegument, while dead worms showed that their damaged tegument adhered to the vessel and inflammatory cell attached on and penetrated into the worm body. Twenty-four hours to 3 days posttreatment, the degenerated schistosomulum sections decreased from 28.1% to 8.2%, while the sections of dead schistosomula increased from 60.0% to 74.8%. At these time periods, the damage intensity of degenerated schistosomula aggravated, while dead schistosomula showed disintegration of internal structures infiltrated by eosinophil-predominant inflammatory cells to form the dead worm abscess. Seven days to 14 days posttreatment, no normal schistosomulum section was observed, and the percentages of degenerated and dead worms further decreased from 3.4% to 3.0% and 34.4% to 12.6%, respectively. Meanwhile, 62.2% to 84.4% of dead worms developed to dead worm granulomas and part of them situated in early stage. Twenty-eight days posttreatment, only dead worm granulomas were observed in the liver sections and part of them developed to late stage. The results indicate that a smaller single mefloquine dose 200 mg/kg exhibits a potential and fast killing effect against S. japonicum juvenile and induces severe histopathological lesions.

Effectiveness of synthetic trioxolane OZ78 against Schistosoma japonicum in mice and rabbits.

Antischistosomal activities of a synthetic peroxide OZ78 (an ozonide carboxylic acid) against Schistosoma japonicum have been studied in mice and rabbits. Among 132 mice used, 30 of them were infected with 80-100 S. japonicum cercariae for collection of juvenile and adult schistosomes applied in in vitro tests. The remaining 102 mice were infected with 40 schistosome cercariae used for experimental treatment. Other 13 rabbits infected each with 200 schistosome cercariae were treated orally with OZ78 42 days post-infection. Most treated mice and rabbits were sacrificed 4 weeks post-treatment to collect residual schistosomes for evaluation of the drug efficacy. OZ78 and its sodium salt (OZ78-Na salt) 10-60 µg/mL alone exhibited no in vitro effect against day 14, day 21 schistosomula, and day 35 adult schistosomes. But OZ78 and OZ78-Na salt 10 and 20 µg/mL together with hemin 80 µg/mL showed decrease in worm motor activity and severe damage to the worm tegument and intestine, and all worms died within 3 days post-incubation. After infected mice were treated orally with OZ78 at a single dose of 400 mg/kg for 1 day, 34.9% of the worms shifted to the liver. Three and 7 days post-treatment, 100% of the worms were recovered from the liver. Fourteen days post-treatment, 92.3% of the worms still remained in the liver and 7.7% of the worms returned back to the mesenteric veins. Male and female worms shifted to the liver revealed in apparent shrinkage, degeneration of worm body, depigmentation in gut, and disappearance of ova in the uterus of some female worms. Meanwhile, dead worm and dead worm fragments were found in the liver tissues. In mice infected with various stages of schistosomes and treated orally with single OZ78 400 mg/kg, moderate or potential effect of the drug against day 0 (3-h-old worm), day 7, day 14, and day 21 juvenile worms and day 28, day 35 as well as day 42 adult worms were observed, the differences of total or female worm burdens between each treated group and control group were statistically significant (P < 0.01 or P < 0.05). Among the various stages of juveniles, day 7 worms were more susceptible to OZ78 with worm reduction of 83.8%, while the effect of OZ78 against day 28 to day 42 adult worms were similar. Finally, rabbits infected with adult schistosomes and treated with OZ78 at a single dose of 45 mg/kg or a daily dose of 35 mg/kg for three consecutive days resulted in significantly lower total and female worm burdens in comparison with that of control (P < 0.05) with total and female worm reductions of 84.1% and 84.7% as well as 74.3% and 77.4%, respectively. The results demonstrate that OZ78 possesses effect against both juvenile and adult S. japonicum in mouse model, and also shows effect against adult schistosomes in rabbits.

Confocal laser scanning microscopic observation on adult Schistosoma japonicum harbored in mice following treatment with single-dose mefloquine.

The aim of the present study is to assess the mefloquine-induced alteration of adult Schistosoma japonicum using confocal laser scanning microscopy (CLSM). Eight out of ten mice infected with 60-80 S. japonicum cercariae for 35 days were treated orally with mefloquine at a single dose of 400 mg/kg. Four groups of two mice were killed at 24 h and 3, 7, and 14 days post-treatment, and schistosomes were collected by perfusion from the liver and mesenteric veins, fixed in 70% alcohol, stained with acid carmine, and examined by CLSM. Worms obtained from untreated mice served as controls. Twenty-four hours post-treatment, focal tegument of adult male and female worms, which composed of fine and short villus-like materials, became thicker and longer, or disorder arrangement, while the musculatures beneath the tegument revealed in focal and irregular swelling with various degrees. In the gut of male and female schistosomes, severe dilatation accompanied by swelling, collapse, and peeling of gut mucosa was universal. In the reproductive organs, no apparent alteration in the testis structure of male worms was seen, while in female worms, slight damage to the ovary included loose arrangement of mature ovary cells accompanied by some of them degenerated and collapsed. As to vitelline glands, severe damage, such as swelling, indistinction, fusion or collapse of vitelline cells, and apparent swelling of parenchymal tissues in vitelline gland lobules, was seen. Meanwhile, abnormal ova emerged in the uterus at this time point. Three to 7 days post-treatment, the damage to the worms aggravated either in extent or in severity along with time. In some focally swollen worm body, the parenchymal tissues revealed in severe swelling. In addition, a large piece of degenerated and necrotic parenchymal tissues emerged closed to the severe destructed oral or ventral sucker. In the gut of male and female worms, the major alterations manifested by focal collapse or peeling of mucosa, and desquamation of gut epithelial cells. As to the reproductive organs, the testes of male worms revealed in reduction of size, decrease in number of germinative cells, and some of them showed degeneration and collapse, or destruction of the capsule around the testis. In female worms, some ovaries only showed degenerated and collapsed cells accompanied with many cell fragments. Meanwhile, almost all of the vitelline cells lost their definition, which revealed in indistinct cell structure, fusion of some cells, and formation of many cell fragments due to their collapse. Fourteen days post-treatment, only some male worms survived the treatment were collected. Their tegument and musculature showed prominent recovery, but severe damage to the gut and testes was still observed. Our results confirm that under the observation by CLSM, mefloquine exhibits destructive effect on adult S. japonicum, particularly the morphological structure of digestive system and reproductive system of the worms.