An adjuvant effect of Metformin as an anti-fibrotic agent when administered with the anti-schistosomal Praziquantel in Schistosoma mansoni infected mice

@#Schistosomiasis is the second most common parasitic disease post Malaria around the world. Praziquantel (PZQ) is known as the most efficient anti- schistosomal drug but has no anti-fibrotic effect. Metformin (Met) is a well-known drug for type 2 diabetes. This study aimed to evaluate the role of Met as anti-schistosomal and anti-fibrotic agents alone or in combination with PZQ treatment. Forty male CD1 mice were divided into four groups (n=10 mice) as following; the first group (Gp1) was served as a negative control. Gp2, Gp3, Gp4, and Gp5 were infected with (60-80) S. mansoni cercariae. After a month of infection, Gp3 was administered orally with PZQ (500 mg/Kg) for 2 consecutive days. Gp4 was administered orally with Met (150 mg/Kg) for 15 consecutive days, and Gp5 was orally administered with PZQ followed by Met for 15 consecutive days at the same doses as in Gp 3 and 4. The results showed that PZQ had potent worms and egg reduction in liver and intestine tissues with no anti-fibrotic effect of the granuloma formation. However, Met or PZQ/Met treatment postinfection led to a reduction in egg count in both liver and intestine tissues with a significant reduction in granuloma site. Treatment of S. mansoni-infected mice with Met or PZQ/Met ameliorated the hematological and biochemical alterations induced by S. mansoni infection. Collectively, Met has no anti-schistosomal activity but led to a reduction in egg deposition and showed an anti-fibrotic effect on granulomatous development either when used alone or in combination with PZQ treatment. This study shed light on the possible role of Met as an anti-fibrotic agent when administered with PZQ for S. mansoni infected humans.

Ortho-nitrobenzyl derivatives as potential anti-schistosomal agents

ABSTRACT In the search for new anti-schistosomal agents, a series of fifteen ortho-nitrobenzyl derivatives was assayed in vitro against both the schistosomulum (somule) and adult forms of Schistosoma mansoni. Compounds 8 and 12 showed significant activity against somules at low micromolar concentrations, but none was active against adults. The SAR demonstrated that the compounds most active against the parasite were mutagenic to the human cell line RKO-AS45-1 only at concentrations 10- to 40-fold higher than the worm-killing dose. Given their electrophilicity, compounds were also screened as inhibitors of the S. mansoni cysteine protease (cathepsin B1) in vitro. Amides 5 and 15 exhibited a modest inhibition activity with values of 55.7 and 50.6 % at 100 µM, respectively. The nitrobenzyl compounds evaluated in this work can be regarded as hits in the search for more active and safe anti-schistosomal agents.

Anti-schistosomal activities of Echinops kebericho Mesfin root and Hagenia abyssinica (Bruce) J.F Gmel flower part crude extracts in Swiss albino mice

Objective:To evaluate the in vivo antischistosomal activities of the crude extracts of Echinops kebericho Mesfin (E. kebericho) root and Hagenia abyssinica (Bruce) J.F. Gmel (H. abyssinica) flower.Methods:Mice were infected with (150 ± 10) Schistosoma mansoni cercariae by paddling technique. Crude extracts were administered orally for five consecutive days at doses of 300, 600 and 1 200 mg/kg/day along with 200 mg/kg/day praziquantel and 3% tween 80 given as a control.Results:E. kebericho root extract showed a statistically significant (P < 0.05) reduction in fecal egg count of 64.44%, 42.96% & 26.82% and worm burden of 65.71%, 47.86% & 31.43% at treatment doses of 1 200 mg/kg/day, 600 mg/kg/day and 300 mg/kg/day, respectively. Similarly, H. abyssinica flower extracts showed a significant (P < 0.05) reduction in fecal egg count up to 84.57%, 77.06% & 63.89% and worm burden of 91.43%, 81.43% & 70.71% at a respective dose levels. In addition, a significant (P < 0.05) reduction in liver granuloma score was observed in all H. abyssinica administered dose groups and E. kebericho at 1 200 mg/kg/day dose group as compared to infected untreated control group.Conclusions:H. abyssinica and E. kebericho crude extracts show a promising antischistosomal activity.

Anti-schistosomal activities of Echinops kebericho Mesfin root and Hagenia abyssinica (Bruce) J.F Gmel flower part crude extracts in Swiss albino mice

Objective: To evaluate the in vivo antischistosomal activities of the crude extracts of Echinops kebericho Mesfin (E. kebericho) root and Hagenia abyssinica (Bruce) J.F. Gmel (H. abyssinica) flower. Methods: Mice were infected with (150 ± 10) Schistosoma mansoni cercariae by paddling technique. Crude extracts were administered orally for five consecutive days at doses of 300, 600 and 1 200 mg/kg/day along with 200 mg/kg/day praziquantel and 3% tween 80 given as a control. Results: E. kebericho root extract showed a statistically significant (P < 0.05) reduction in fecal egg count of 64.44%, 42.96% & 26.82% and worm burden of 65.71%, 47.86% & 31.43% at treatment doses of 1 200 mg/kg/day, 600 mg/kg/day and 300 mg/kg/day, respectively. Similarly, H. abyssinica flower extracts showed a significant (P < 0.05) reduction in fecal egg count up to 84.57%, 77.06% & 63.89% and worm burden of 91.43%, 81.43% & 70.71% at a respective dose levels. In addition, a significant (P < 0.05) reduction in liver granuloma score was observed in all H. abyssinica administered dose groups and E. kebericho at 1 200 mg/kg/day dose group as compared to infected untreated control group. Conclusions: H. abyssinica and E. kebericho crude extracts show a promising antischistosomal activity.

Antischistosomal activity from Brazilian marine algae

Abstract Schistosomiasis may be caused by six different species of the genus Schistosoma. Current treatment is based only on two drugs: oxamniquine, which is only effective against the Schistosoma mansoni species, and praziquantel, which is ineffective against young parasites. Therefore, research on new drugs and their targets for the treatment of this disease is urgently needed. In the present work, the efficacies of several seaweeds extracts against S. mansoni were tested. Worm couples were incubated with different concentration of seaweed extracts for 120 h and monitored after the first 2 h and then every 24 h to evaluate death, mobility reduction and couple detachment. The extracts of 13 different seaweed species were tested in a first trial and the active extracts were further evaluated in lower concentrations. The extracts of Gracilaria ornata and species belonging to the genera Dictyota and Laurencia showed activity at relatively low concentrations. The active extracts were analyzed by LC–MS, and possible candidates are proposed.

Comparison of the <i>in vitro</i> Effects of One-day Exposure to Amodiaquine and Praziquantel on <i>Schistosoma mansoni</i> Adult Worm Pairs

It has been demonstrated that continuous exposure to amodiaquine (AQ) alone elicits <i>in vitro</i> antischistosomal activities at concentrations of 1–10 μg/ml. However, orally administered drugs reach a peak blood concentration within one or two hours and then gradually decrease. The blood concentration does not remain at a constant level over several days as <i>in vitro</i> concentration of continuous drug exposure. <i>In vitro</i> activities by one day exposure to AQ better reflect the actual antischistosomal activities after oral administration than those elicited by continuous exposure.The objective of the present study is to compare the antischistosomal potential of one-day exposure to AQ with that to praziquantel (PZQ), a current antischistosomal drug. <i>Schistosoma mansoni</i> adult worm pairs were incubated with 0 (control), 1, 2, 5 and 10 μg/ml AQ as well as 0.01, 0.02, 0.05 and 0.1 μg/ml PZQ for the first day, and were subsequently incubated in drug-free media for a period of 14 days. The one-day exposure to AQ significantly reduced the daily egg output of the worm pairs at 1–10 μg/ml. The inhibitory effect on egg production continued at 5 and 10 μg/ml but proved temporary at 1 and 2 μg/ml. Furthermore, AQ-induced specific morphological alterations (severe swelling and/or localization of hemozoin) were observed in the worms at 5 and 10 μg/ml. The AQ-specific appearance of the male worms gradually faded during subsequent incubation in drug-free media, although the female worms showed elongation. Meanwhile, PZQ inhibited the egg output of adult worm pairs at concentrations of 0.01–0.1 μg/ml during exposure. The inhibitory effect on egg production continued at 0.05 and 0.1 μg/ml but proved temporary at 0.01 and 0.02 μg/ml. Furthermore, PZQ induced a visible contraction and shortening of the male and female worms at 0.05 and 0.1 μg/ml during exposure, but the PZQ-specific alterations quickly disappeared during subsequent incubation in drug-free media. To our knowledge, this is the first report showing that one-day exposure to AQ inhibits the egg production of adult worm pairs at 1–10 μg/ml and induces specific morphological alterations in the worms at 5 and 10 μg/ml. The present findings have important implications for the evaluation of the therapeutic effects of both AQ monotherapy and combination therapy with artesunate on schistosomiasis in clinical field trials.

<i>Comparison of the in vitro</i> effects of one-day exposure to amodiaquine and praziquantel on <i>Schistosoma mansoni</i> adult worm pairs

It has been demonstrated that continuous exposure to amodiaquine (AQ) alone elicits <i>in vitro</i> antischistosomal activities at concentrations of 1 - 10 µg/ml. However, orally administered drugs reach a peak blood concentration within one or two hours and then gradually decrease. The blood concentration does not remain at a constant level over several days as <i>in vitro</i> concentration of continuous drug exposure. <i>In vitro</i> activities by one day exposure to AQ better reflect the actual antischistosomal activities after oral administration than those elicited by continuous exposure.The objective of the present study is to compare the antischistosomal potential of one-day exposure to AQ with that to praziquantel (PZQ), a current antischistosomal drug. <i>Schistosoma mansoni</i> adult worm pairs were incubated with 0 (control), 1, 2, 5 and 10 µg/ml AQ as well as 0.01, 0.02, 0.05 and 0.1 µg/ml PZQ for the first day, and were subsequently incubated in drug-free media for a period of 14 days. The one-day exposure to AQ significantly reduced the daily egg output of the worm pairs at 1 - 10 µg/ml. The inhibitory effect on egg production continued at 5 and 10 µg/ml but proved temporary at 1 and 2 µg/ml. Furthermore, AQ-induced specific morphological alterations (severe swelling and/or localization of hemozoin) were observed in the worms at 5 and 10 µg/ml. The AQ-specific appearance of the male worms gradually faded during subsequent incubation in drug-free media, although the female worms showed elongation. Meanwhile, PZQ inhibited the egg output of adult worm pairs at concentrations of 0.01 - 0.1 µg/ml during exposure. The inhibitory effect on egg production continued at 0.05 and 0.1 µg/ml but proved temporary at 0.01 and 0.02 µg/ml. Furthermore, PZQ induced a visible contraction and shortening of the male and female worms at 0.05 and 0.1 µg/ml during exposure, but the PZQ-specific alterations quickly disappeared during subsequent incubation in drug-free media. To our knowledge, this is the first report showing that one-day exposure to AQ inhibits the egg production of adult worm pairs at 1 - 10 µg/ml and induces specific morphological alterations in the worms at 5 and 10 µg/ml. The present findings have important implications for the evaluation of the therapeutic effects of both AQ monotherapy and combination therapy with artesunate on schistosomiasis in clinical field trials.

Antischistosomal activity of a calcium channel antagonist on schistosomula and adult Schistosoma mansoni worms

Current schistosomiasis control strategies are largely based on chemotherapeutic agents and a limited number of drugs are available today. Praziquantel (PZQ) is the only drug currently used in schistosomiasis control programs. Unfortunately, this drug shows poor efficacy in patients during the earliest infection phases. The effects of PZQ appear to operate on the voltage-operated Ca2+channels, which are located on the external Schistosoma mansoni membrane. Because some Ca2+channels have dihydropyridine drug class (a class that includes nifedipine) sensitivity, an in vitro analysis using a calcium channel antagonist (clinically used for cardiovascular hypertension) was performed to determine the antischistosomal effects of nifedipine on schistosomula and adult worm cultures. Nifedipine demonstrated antischistosomal activity against schistosomula and significantly reduced viability at all of the concentrations used alone or in combination with PZQ. In contrast, PZQ did not show significant efficacy when used alone. Adult worms were also affected by nifedipine after a 24 h incubation and exhibited impaired motility, several lesions on the tegument and intense contractility. These data support the idea of Ca2+channels subunits as drug targets and favour alternative therapeutic schemes when drug resistance has been reported. In this paper, strong arguments encouraging drug research are presented, with a focus on exploring schistosomal Ca2+channels.

In vitro effects of amodiaquine on paired Schistosoma mansoni adult worms at concentrations of less than 5 µg/mL

In this study, the in vitro effects of amodiaquine (AQ) monotherapy on the egg output of paired adult Schistosoma mansoni worms and their survival during in vitro culture were assessed. In addition, the gross morphological alterations of male and female worms caused by AQ were visually observed under a dissecting microscope. AQ significantly reduced the daily egg output of paired adult S. mansoni worms following incubation for 14 days at 1-5 µg/mL, but not at 0.5 µg/mL, compared with the control group. AQ also reduced the survival of male and female worms at concentrations of 2 and 5 µg/mL, respectively. Moreover, exposure to 5 µg/mL AQ caused severe swelling and/or localisation of black content in the body of all male and female worms within one or two days of incubation; subsequently, shrinkage in the male worms and elongation in the female worms were observed. The initial morphological alterations caused by AQ occurred along the intestinal tract of the male and female worms. To our knowledge, this is the first study to report not only the efficacy of AQ at concentrations lower than 5 µg/mL on paired adult S. mansoni worms, but also the effects of AQ on the intestinal tracts of worms in in vitro culture.

In vitro effect of current antimalarial drugs on the survival of paired Schistosoma mansoni adult worms and their egg production

Some field trials have already demonstrated the high antischistosomal potential of combination therapies using Artesunate (ART) and current antimalarial drugs (Boulanger <I>et al.,</I> 2007; Mohamed <I>et al.,</I> 2009; Sissoko <I>et al.,</I> 2009). The antischistosomal effects of these drugs are noteworthy, especially when they are used for the treatment of malaria in schistosomiasis endemic areas. However, the antischistosomal effects of Amodiaquine (AQ), Primaquine (PQ), Chloroquine (CQ) and Pyrimethamine (Py) have never been assessed by <I>in vitro</I> incubation. The objective of the present study is to assess the <I>in vitro</I> effects of current antimalarial drugs on the egg productivity of adult worm pairs of <I>S. mansoni</I> and their survival times. The effect of the current antimalarial drugs Mefloquine (MQ), quinine (QN), AQ, PQ, CQ, Sulfadiazine (Sf) and Py on the egg output of adult worm pairs of <I>Schistosoma mansoni</I> and their survival times during <I>in vitro</I> culture were assessed at a concentration of 10 Μg⁄ml. AQ, PQ, CQ and Py significantly inhibited the daily egg output of paired female worms at a concentration of 10 Μg⁄ml during the 1 or 2-day <I>in vitro</I> cultivation. However, QN and Sf did not significantly affect the daily egg output during the 8-day incubation. One-day exposure to MQ killed all paired male and female adult worms. AQ and PQ significantly decreased the survival of both paired male and female worms during the 14-day incubation, but QN, CQ, Py and Sf did not exert any similar effect. The present result is consistent with an assessment of the antischistosomal effects of artemisinin-based combination therapy in malaria and schistosomiasis co-endemic areas.

Schistosomiasis: a fourteen year survey of cases admitted to the U.S.T. Charity Hospital

In the U.S.T. Charity Hospital for the past 14 years, 1946-1959, a total of 127 cases of schistosomiasis were admitted. The majority 150 in number, came after 1950Majority of these patients came either from Leyte or Samar, 48 from the former and 34 from the later with a slight female predominance of 56.7% and a major age distribution between 10-30 years or 68.52%Diagnosis was confirmed in 49 instances by at least one diagnostic aid, Group I, and in others without objective proof but by clinical and epidemiological evidence, Group II. The remainder of the cases, though not showing schistosomiasis in the usual form, disclosed the disease at autopsy, and/or biopsyOn the basis of Pesigans grading, our cases chiefly belong to Grades C and D with a few in Grade E. Lack of cases in Grade A and B was probably due to the distant location of our hospital from endemic areas, and therefore the unlikelihood of getting early casesClinically abdominal complaints were the predominant feature, in the form of diarrhea or dysentery, abdominal pain, liver involvement including portal hypertension, jaundice and splenomegaly. Hematemesis and melena featured in 14% of the casesStools examination with acid-ether concentration technique proved the more reliable objective diagnostic aid in our series, followed by skin test and of course histological studiesThe frequency of involvement of the appendix in our cases stresses this particular aspect of the disease. The liver, colon, lungs and spleen were also frequently affected. In most instances, co-existing parasitic disease is also found. Of special interest are 4 cases which showed co-existing malignancy of either liver or intestines, a finding deserving further study. Likewise, calcification in one of the abdominal viscera appears to be one important clue in this disease, especially in a patient coming from an endemic areaAs far as Fuadin therapy is concerned, as used in this series, results were variable. In some cases control of diarrhea, relief of abdominal pain, subsidence of fever were achieved. In the advanced cases with irreversible hepato-splenomegaly, no noticeable change was observed. (Summary)