Sanguinarine: an alkaloid with promising in vitro and in vivo antiparasitic activity against different developmental stages of Schistosoma mansoni and in silico pharmacokinetic properties (ADMET).

The objective of the study was to evaluate the in vitro and in vivo schistosomicidal activity of sanguinarine (SA) on Schistosoma mansoni and its in silico pharmacokinetic parameters. ADMET parameters and oral bioavailability were evaluated using the PkCSM and SwissADME platforms, respectively. The activity of SA in vitro, at the concentrations of 1.0-25 µM, was analyzed through the parameters of motility, mortality, and cell viability of the worms at intervals of 3-24 h. Mice were infected with cercariae and treated by gavage with SA (5 mg/kg/day, in a single dose or two doses of 2.5 mg/kg every 12 h for 5 consecutive days) on the 1st (skin schistosomula), 14th (pulmonary schistosomula), 28th (young worms), and 45th (adult worms) days after infection. In vitro and in vivo praziquantel was the control. In vitro, SA showed schistosomicidal activity against schistosomula, young worms, and couples; with total mortality and reduced cell viability at low concentrations and incubation time. In a single dose of 5 mg/kg/day, SA reduces the total worm load by 47.6%, 54%, 55.2%, and 27.1%, and female worms at 52.0%, 39.1%, 52.7%, and 20.2%, respectively, results which are similar to the 2.5 mg/kg/day dose. SA reduced the load of eggs in the liver, and in histopathological and histomorphometric analyses, there was a reduction in the number and volume of hepatic granulomas, which exhibited less inflammatory infiltrate. SA has promising in vitro and in vivo schistosomicidal activity against different developmental stages of S. mansoni, in addition to reducing granulomatous liver lesions. Furthermore, in silico, SA showed good predictive pharmacokinetic ADMET profiles.

Effects of the probiotic Bacillus cereus GM on experimental schistosomiasis mansoni.

Probiotics contribute to the integrity of the intestinal mucosa and preventing dysbiosis caused by opportunistic pathogens, such as intestinal helminths. Bacillus cereus GM obtained from Biovicerin® was cultured to obtain spores for in vivo evaluation on experimental schistosomiasis. The assay was performed for 90 days, where all animals were infected with 50 cercariae of Schistosoma mansoni on the 15th day. Three experimental groups were formed, as follows: G1-saline solution from the 1st until the 90th day; G2-B. cereus GM (105 spores in 300 µL of sterile saline) from the 1st until the 90th day; and G3-B. cereus GM 35th day (onset of oviposition) until the 90th day. G2 showed a significant reduction of 43.4% of total worms, 48.8% of female worms and 42.5% of eggs in the liver tissue. In G3, the reduction was 25.2%, 29.1%, and 44% of the total number of worms, female worms, and eggs in the liver tissue, respectively. G2 and G3 showed a 25% (p < 0.001) and 22% (p < 0.001) reduction in AST levels, respectively, but ALT levels did not change. ALP levels were reduced by 23% (p < 0.001) in the G2 group, but not in the G3. The average volume of granulomas reduced (p < 0.0001) 65.2% and 46.3% in the liver tissue and 83.0% and 53.2% in the intestine, respectively, in groups G2 and G3. Th1 profile cytokine (IFN-γ, TNF-α, and IL-6) and IL-17 were significantly increased (p < 0.001) stimulated with B. cereus GM in groups G2 and G3. IL-4 showed significant values when the stimulus was mediated by ConA. By modulating the immune response, B. cereus GM reduced the burden of worms, improved some markers of liver function, and reduced the granulomatous inflammatory reaction in mice infected with S. mansoni, especially when administered before infection.

Respiratory allergy symptoms and cytokine profiles in the presence of anti-Ascaris antibody in Giardia lamblia-infected children.

Anti-Ascaris lumbricoides (Asc) IgE and IgG can immunomodulate the allergy; however, the influence of these isotypes has not been investigated in the giardiasis and allergy. Therefore, the frequency of respiratory allergy (RA) symptoms in Giardia lamblia-infected children, with or without anti-Asc IgE, IgG1, or IgG4 and Th1, Th2/Treg, and Th17 cytokine production, was evaluated. We performed a case-control study with children aged 2-10 years old selected by questionnaire and stool exams to form the groups: infected or uninfected with RA (G-RA, n = 55; nG-RA, n = 43); infected and uninfected without RA (G-nRA, n = 59; nG-nRA, n = 54). We performed blood leukocyte counts and in vitro culture. Cytokine levels in the supernatants (CBA), serum total IgE and anti-Asc IgE (ImmunoCAP), IgG1, IgG4, and total IgA (ELISA) were measured. Infection was not associated with allergy. Infected children showed increased levels of anti-Asc IgG1, IL-2, IFN-γ, IL-4, and IL-10. There was a lower frequency of allergy-related symptoms in anti-Asc IgG1-positive children than IgG1-negative (OR = 0.38; CI = 0.17-0.90, p = 0.027) and few eosinophils in G-RA than in G-nRA and more in G-nRA than in nG-nRA, whereas TNF-α levels were higher in the G-RA than in the nG-nRA group. For infected and positive anti-Asc IgG1, there was higher TNF-α and IL-10 production than G/-IgG1. IL-10 levels were lower in nG/ + IgG1 than in infected or non-infected, and both were negative for anti-Asc IgG1. Th1/Th2/IL-10 profiles were stimulated in the infected patients, and in those with circulating anti-Asc IgG1, the TNF-α production was strengthened with a lower risk for respiratory allergy symptoms.

Schistosomicidal, hepatoprotective and antioxidant activities of the N-acetyl-L-cysteine and/or praziquantel in experimental acute mansonic schistosomiasis.

Schistosomiasis is a tropical parasitic disease, in which the major clinical manifestation includes hepatosplenomegaly, portal hypertension, and organs fibrosis. Clinically, treatment of schistosomiasis involves the use of praziquantel (PZQ) and supportive care, which does not improve the patient's outcome as liver injuries persist. Here, we report for the first time the effect of N-acetyl-L-cysteine (NAC) and/or praziquantel (PQZ) on S. mansoni, hepatic granuloma, serum markers for liver function and oxidative damage in acute schistosomiasis. Infected mice were divided into control, NAC, PZQ and NAC+PZQ groups and uninfected into control and NAC groups. After infection, NAC (200 mg/kg/day) was administrated until the 60th day and PZQ (100 mg/kg/day) from the 45th to the 49th day, both orally. On day 61, the mice were euthanized for serum markers for liver function. Worms were recovered, fragments of intestine employed to ascertain the oviposition pattern, and the liver was used for histopathological analysis, histomorphometry, egg and granuloma counting and oxidative stress marker assays. NAC reduced the burden of worms and eggs and increased the dead eggs in intestinal tissue. NAC+PZQ brought about reduction in granulomatous infiltration and NAC and/or PZQ reduced levels of ALT, AST, and alkaline phosphatase and increased albumin. NAC, PZQ or NAC+PZQ reduced levels of the superoxide anion, lipid peroxidation and protein carbonyl and increased sulfhydryl groups. The reduction in parasitological parameters, granulomatous inflammation and oxy-redox imbalance suggests NAC acts as a adjuvant in treatment of acute experimental schistosomiasis.

Immunohistopathological changes in murine Schistosomiasis mansoni under the influence of N-acetyl-L-cysteine.

The main pathology associated with Schistosomiasis mansoni is granulomatous inflammation that may develop into hepatosplenic disease with fibrosis and hepatoesplenomegaly. It is known that N-acetyl-L-cysteine (NAC) reduces tissue damage in chronic liver diseases owing to its anti-inflammatory, antioxidant, and detoxifying properties. In this study, we investigated the imunohistopathological changes in murine schistosomiasis mansoni under the influence of NAC, in combination with Praziquantel (PZQ) or not. Three groups of mice were formed to evaluate the effects of NAC during infection in the acute, intermediate, and chronic phases. Each group was further subdivided into four subgroups: NAC, PZQ, NAC + PZQ and control (without treatment). Oral administration of NAC (200 mg/kg/day) was carried out on the first day after infection for the acute phase and on the 45th for the intermediate and chronic phases for 59 and 45, 75 days, respectively. PZQ (100 mg/kg/day), was given orally by gavage from the 45th to 49th day after infection. Histopathological analysis of liver tissue provided evidence that combined NAC + PZQ treatment reduced the development of granulomas observed in the chronic phase. Animals treated with NAC and/or PZQ showed a reduction in the size of granulomas and all those treated with NAC exhibited a lower degree of fibrosis. In all groups, NAC decreased the synthesis of interferon-γ and nitric oxide, while increasing the levels of interleukin-10, but it did not influence the production of interleukin-4. On the whole, NAC treatment induced an immunomodulatory effect and reduced liver damage during the granulomatous inflammation in S. mansoni-infected mice.

Ultrastructural analysis of miltefosine-induced surface membrane damage in adult Schistosoma mansoni BH strain worms.

Schistosomiasis is an infectious parasitic disease caused by helminths from the genus Schistosoma; it affects over 200 million people globally and is endemic in 70 countries. In Brazil, 6 million individuals are infected with Schistosoma mansoni. Furthermore, as the prevalence of S. mansoni infections is increasing, approximately 26 million citizens in 19 Brazilian states are at risk for infection. Schistosomiasis disease control involves predominately the administration of a single drug, praziquantel. Although praziquantel exhibits chemotherapeutic efficacy and safety, its massive use in endemic zones, the possibility of the emergence of drug-resistant Schistosoma parasites, and the lack of another efficacious antischistosomal drug demand the discovery of new schistosomicidal compounds. First developed as anti-tumor drug, miltefosine is an alkylphospholipid derivative that exhibits bioactivity against Leishmania and Trypanosoma parasites, free-living protozoa, bacteria, and fungi. With its anti-parasite activity, miltefosine was the first orally administered drug against visceral and cutaneous leishmaniasis approved. Previously, by means of the MTT cytotoxic assay and a DNA fragmentation test, we verified that, at doses of 100 and 200 µM (40 and 80 µg/mL), miltefosine exhibited in vitro schistosomicidal activity against adult S. mansoni worms. Here, we present ultrastructural evidence of rapid, severe miltefosine-induced surface membrane damage in S. mansoni following drug treatment. The number of dead parasites was concentration- and time-dependent following miltefosine treatment. At a miltefosine concentration of 200 µM (∼80 µg/mL), in vitro parasite killing was initiated as early as 3 h post-incubation, and it was maximal after 24 h of treatment. The parasite death was preceded by progressive surface membrane damage, characterized by tegument peeling, spine reduction and erosion, blister formation and rupture, and the emergence of holes. According to our present results, miltefosine is very effective at inducing membrane destruction of S. mansoni with a short onset of pharmacological action.