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.

Potential of pharmaceutical formulation based on Morinda citrifolia extract for the treatment of schistosomiasis.

Schistosomiasis is a parasitic disease that can be asymptomatic, but it can progress and cause serious damage, such as hospitalization and death. This work aimed to characterize and carry out the in vivo pharmacological test of the dry extract of Morinda citrifolia and obtain a pharmaceutical dosage form based on this extract for the treatment of schistosomiasis. The aqueous extract was characterized based on the evaluation of pH, dry residue and density. The aqueous extract was dried through the freeze-drying process. The obtained dry extract was characterized through phytochemical screening, rheological analysis, acute toxicity and in vivo pharmacology. Additionally, the pre-formulation development of a pharmaceutical dosage form was pursued with the dry extract. Through the HPLC chromatogram, characteristic rutin peaks were identified. The rheological behavior of the dry extract did not show good characteristics. Acute toxicity, at a dose of 2000 mg/kg, showed excitatory activity in the central and autonomous nervous system. The in vivo pharmacological test of the dry extract showed that, at a dose of 400 mg/kg, it was possible to reduce 67.5% of the total adult worms, 66% of female worms and 60% of the number of eggs. The pharmaceutical dosage form obtained was an oral solution that was clear, transparent, without the presence of lumps and precipitates, having a density of 1.1276 g mL-1 and pH of 5.92. The results obtained will provide parameters for the production of suitable pharmaceutical formulations, as well as for the quality control of products based on M. citrifolia, with promising schistosomicidal activity.

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.

Toxic, cytotoxic and genotoxic effect of plumbagin in the developmental stages of Biomphalaria glabrata (Say, 1818-intermediate host) and cercaricidal activity against the infectious agent of schistosomiasis mansoni.

BACKGROUND: Snails of the genus Biomphalaria are intermediate hosts of Schistosoma mansoni, the main etiological agent of schistosomiasis mansoni, which affects about 236.6 million people in tropical and subtropical regions of the world. The World Health Organization recommends the population control of vector snails as one of the strategies to reduce the prevalence and incidence of schistosomiasis. In this study, molluscicidal and antiparasitic activities of plumbagin, a naturally sourced naphthoquinone with a range of biological effects, were evaluated against B. glabrata and cercariae of S. mansoni. RESULTS: After 24 h of exposure, plumbagin demonstrated molluscicidal activity at low concentrations against embryos (LC50 of 0.56, 0.93, 0.68, 0.51 and 0.74 µg mL-1 for the blastula, gastrula, trochophore, veliger and hippo stage, respectively) and adult snails (LC50 of 3.56 µg mL-1 ). There were no changes in exposed snails' fecundity or fertility; however, plumbagin was able to increase the frequency of DNA damage and the number of hemocytes, with apoptosis and binucleation being the main hemocyte alterations. In addition, plumbagin showed death of S. mansoni cercariae in the concentration of 1.5 µg mL-1 in 60 min, while showing moderate toxicity to Artemia salina. CONCLUSION: Plumbagin proved to be a promising substance for the control of B. glabrata population, intermediate host of S. mansoni, as well as the cercariae, infective stage for humans (definitive host), while being moderately toxic to A. salina, a crustacean widely used in ecotoxicity tests. © 2022 Society of Chemical Industry.

In vitro activity, ultrastructural studies and in silico pharmacokinetic properties of indol-3-yl-thiosemicarbazones derivatives and analogues against juvenile and adult worms of S. mansoni.

The present work aimed to carry out in vitro biological assays of indol-3-yl derivatives thiosemicarbazones (2a-e) and 4-thiazolidinones (3a-d) against juvenile and adult worms of S. mansoni, as well as the in silico determination of pharmacokinetic parameters for the prediction of the oral bioavailability of these derivatives. All compounds were initially screened at a concentration of 200 µM against S. mansoni adult worms and the results evidenced the good activity of compounds 2b, 2d and 3b, which caused 100% mortality after 24, 48 and 72 h, respectively. Subsequent studies with these same compounds revealed that compound 2b was able to reduce the viability of the parasites by 85% and 83% at concentrations of 200 and 100 µM, respectively. In relation to the juvenile worms, all compounds (2b, 2d and 3b) were able to cause mortality, but compound 2b demonstrated better activity causing 100% mortality in 48 h. Additionally, it was possible to observe reduction in the viability of juvenile worms of 85%, 81% and 64% at concentrations of 200, 100 and 50 µM, respectively. Several ultrastructural damages were observed when adult and juvenile S. mansoni worms were exposed to compound 2b (200 µM) that was characterized by extensive destruction by the integument, which may justify the mortality rate of cultured parasites. In the DNA interaction assay, fragmentation of the genetic material of adult worms when treated with compound 2b (200 µM) was evidenced, indicating the apoptosis process as mechanism of parasite death. Regarding pharmacokinetic properties, all derivatives are according to the required parameters, predicting good oral bioavailability for the studied compounds. The results presented in this study reveal the good activity of compound 2b in both adult and juvenile worms of S. mansoni, pointing this compound as promising in the development of further studies on schistosomicidal activity.

A penta-substituted pyridine alkaloid from the rhizome of Jatropha elliptica (Pohl) Muell. Arg. is active against Schistosoma mansoni and Biomphalaria glabrata.

Jatropha elliptica is a shrub distributed throughout the north and west of Brazil and reputedly possesses a wide range of therapeutical properties. The roots of this plant possess molluscicidal activity and contain terpenoids, coumarin, lignoid, steroids and alkaloid. In the present study, we assessed the schistosomicidal, miracicidal and cercaricidal activities (against Schistosoma mansoni) and molluscicidal activities (against adults and egg masses of Biomphalaria glabrata) of the alkaloid diethyl 4-phenyl-2,6-dimethyl-3,5-pyridinedicarboxylate, isolated from the ethanol extract of the rhizome of J. elliptica, have been determined. The alkaloid was 100% lethal to adult schistosomes within 4 days at a concentration of 50 µg/mL. Alterations were observed in the schistosome tegument occasioned by treatment with the alkaloid, such as formation of vesicles and vacuolisation. The extent of tegumental damage of the worm was proportional to the time of incubation and to the concentration of compound. The alkaloid also exhibited a potent cercaricidal activity (LC100 = 2 µg/mL); it was totally ineffective against miracicidal forms of the parasite. Moreover, the alkaloid presented strong activity against adult snails (LC90 = 36.43 µg/mL) but was inactive against their egg masses. It is observed then the potential of this compound for the development of new therapies for the treatment of 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.