Effect of Hydroxyurea on Morphology, Proliferation, and Protein Expression on Taenia crassiceps WFU Strain.

Flatworms are known for their remarkable regenerative ability, one which depends on totipotent cells known as germinative cells in cestodes. Depletion of germinative cells with hydroxyurea (HU) affects the regeneration of the parasite. Here, we studied the reduction and recovery of germinative cells in T. crassiceps cysticerci after HU treatment (25 mM and 40 mM of HU for 6 days) through in vitro assays. Viability and morphological changes were evaluated. The recovery of cysticerci's mobility and morphology was evaluated at 3 and 6 days, after 6 days of treatment. The number of proliferative cells was evaluated using EdU. Our results show morphological changes in the size, shape, and number of evaginated cysticerci at the 40 mM dose. The mobility of cysticerci was lower after 6 days of HU treatment at both concentrations. On days 3 and 6 of recovery after 25 mM of HU treatment, a partial recovery of the proliferative cells was observed. Proteomic and Gene Ontology analyses identified modifications in protein groups related to DNA binding, DNA damage, glycolytic enzymes, cytoskeleton, skeletal muscle, and RNA binding.

Histopathologic evaluation of experimental murine neurocysticercosis after treatment with albendazole/nitazoxanide combination.

Neurocysticercosis (NCC) is the most common helminthic brain infection related to epilepsy. Only albendazole (ABZ) and praziquantel are used in its treatment. The development of new therapeutics has been encouraged. Taenia crassiceps cysticerci intracranial infection is the experimental model used in NCC studies. This study evaluated the histopathology of the brains of BALB/c mice experimentally infected with T. crassiceps cysticerci after the treatment with the ABZ/nitazoxanide (NTZ) combination. Thirty days after the inoculation the mice received an oral single dose of the ABZ/NTZ combination (40 mg kg-1 each). The control groups were treated with: NaCl 0.9%; ABZ or NTZ. The histopathologic evaluation of the brains was performed 24 h after treatment. The ABZ treatment induced discrete mononuclear inflammatory infiltration, meningitis, gliosis, hyperaemia and hippocampus compression; moderate ependimitis and oedema. The NTZ treatment induced accentuated inflammatory infiltration, foamy macrophages, ependimitis, choroiditis, gliosis and hyperaemia and moderate oedema. The ABZ/NTZ combination treatment induced a significant decrease in the polymorphonuclear inflammatory infiltration, ependimitis, choroiditis, gliosis, hyperaemia and ventriculomegaly in comparison with the other groups. The cysticerci showed destruction of the tegument not observed in other groups. The ABZ/NTZ combination is efficient as the parasite showed signs of destruction and lower damage to the host's tissue.

Effect of dexamethasone on albendazole cysticidal activity in experimental cysticercosis by Taenia crassiceps in BALB/c mice: In vitro and in vivo evaluation.

Taenia solium is a parasite whose larvae (cysticerci) can locate in the central nervous system of humans and cause neurocysticercosis (NC). The introduction of cysticidal drugs such as albendazole (ABZ) for the treatment of NC has significantly improved its prognosis. However, treatment is not always effective, and the high levels of corticosteroids used to prevent inflammatory complications in this disease could be, partly, the cause of this observation. In this context, this study investigated, using the experimental mouse model of intraperitoneal infection with Taenia crassiceps, the influence of corticosteroid administration on the therapeutic efficacy of ABZ. We evaluated and compared the effects of ABZ, dexamethasone (DXM) and their combination (ABZ + DXM) on cyst viability, both in vitro and in vivo. Serum levels of IL-4, IFN-gamma, IL-6 and IL-10 were evaluated in the in vivo study. Results showed that the treatment with ABZ, in vitro and in vivo, was associated with a high number of parasites deaths. Concomitant treatment with DXM did not alter ABZ in vitro cysticidal activity but reduced its effectiveness significantly in the in vivo experimental model. Cytokine serum levels did not change significantly in treated mice compared to the controls. The results of this study are relevant as they indicate a negative effect of corticosteroids on the efficacy of cysticidal therapy. In human neurocysticercosis, control of inflammation is of great importance to most patients in order to avoid complications. Corticosteroids are generally used for this purpose and the results of this study demonstrate the need to find other therapeutic strategies. Further studies are needed to better understand the mechanisms involved.

In vitro nitazoxanide exposure affects energetic metabolism of Taenia crassiceps.

Nitazoxanide (NTZ) is a broad-spectrum drug used in intestinal infections, but still poorly explored in the treatment of parasitic tissular infections. This study aimed to evaluate the in vitro responses of the energetic metabolism of T. crassiceps cysticerci induced by NTZ. The organic acids of the tricarboxylic acid cycle, products derived from fatty acids oxidation and protein catabolism were analyzed. These acids were quantified after 24 h of in vitro exposure to different NTZ concentrations. A positive control group was performed with albendazole sulfoxide (ABZSO). The significant alterations in citrate, fumarate and malate concentrations showed the NTZ influence in the tricarboxylic acid (TCA) cycle. The non-detection of acetate confirmed that the main mode of action of NTZ is effective against T. crassiceps cysticerci. The statistical differences in fumarate, urea and beta-hydroxybutyrate concentrations showed the NTZ effect on protein catabolism and fatty acid oxidation. Therefore, the main energetic pathways such as the TCA cycle, protein catabolism and fatty acids oxidation were altered after in vitro NTZ exposure. In conclusion, NTZ induced a significant metabolic stress in the parasite indicating that it may be used as an alternative therapeutic choice for cysticercosis treatment. The use of metabolic approaches to establish comparisons between anti parasitic drugs mode of actions is proposed.

Evaluation of New Benzimidazole Derivatives as Cysticidal Agents: In Vitro, in Vivo and Docking Studies.

Based on our previous research on cysticidal drugs, we report the synthesis and evaluation of three new benzimidazole derivatives. In these compounds, the amido group was used as a bioisosteric replacement of the ester group. The molecular docking on ß-tubulin revealed that the derivatives interacted through hydrogen bonding with N165, E198 and V236. All compounds showed in vitro activity against Taenia crassiceps cysts. Among them, benzimidazole 3 was found to be the most potent of the series (EC50 0.86 µM). This compound also exhibited the highest probability of binding and the lowest binding free energy score and was therefore selected for in vivo evaluation. Results indicated that the efficacy of compound 3 was comparable to that of the reference drug, albendazole (50.39 vs. 47.16% parasite reduction). Animals treated with compound 3 seemed to tolerate this benzimidazole well, with no changes in behavior, or food and water consumption. These findings are consistent with the in silico prediction results, which indicated low toxicity risks. The pharmacokinetic study showed that the half-life and mean residence time (6.06 and 11.9 h, respectively) were long after oral administration. Together, these results indicate that this new benzimidazole derivative represents a promising structure with cysticidal activity.

Gastrointestinal Parasite Infection in Cats in Daegu, Republic of Korea, and Efficacy of Treatment Using Topical Emodepside/Praziquantel Formulation.

The purpose of this study was 2-fold: 1) to investigate the prevalence of gastrointestinal parasite infection in cats reared in Daegu, Republic of Korea and 2) to assess the efficacy and safety of a topical emodepside/praziquantel formulation for cats with parasitic infections. The gastrointestinal parasite infections were examined microscopically using the flotation method. Of 407 cats, 162 (39.8%) were infected by at least one gastrointestinal parasite, including Toxocara cati (63.0%), Toxascaris leonina (31.5%), Taenia taeniaeformis (3.7%), and Cystoisospora felis (1.9%). None of the infected animals had multiple infections. When the data were analyzed according to sex, age, and type of cat, stray cats showed statistically higher prevalence than companion cats (P<0.05). On the 5th day after treatment, no parasitic eggs were detected using microscopic examination. In addition, no adverse effects, such as abnormal behaviors and clinical symptoms, were observed in the cats treated with the drug. These results quantify the prevalence of gastrointestinal parasites in cats in Daegu, Republic of Korea, and show that topical emodepside/praziquantel is a safe and effective choice for treating the parasitic infections in cats.

Proteomic profile associated with cell death induced by androgens in Taenia crassiceps cysticerci: proposed interactome.

Androgens have been shown to exert a cysticidal effect upon Taenia crassiceps, an experimental model of cysticercosis. To further inquire into this matter, the Taenia crassiceps model was used to evaluate the expression of several proteins after testosterone (T4) and dihydrotestosterone (DHT) in vitro treatment. Under 2-D proteomic maps, parasite extracts were resolved into approximately 130 proteins distributed in a molecular weight range of 10-250 kDa and isoelectrical point range of 3-10. The resultant proteomic pattern was analysed, and significant changes were observed in response to T4 and DHT. Based on our experience with electrophoretic patterns and proteomic maps of cytoskeletal proteins, alteration in the expression of isoforms of actin, tubulin and paramyosin and of other proteins was assessed. Considering that androgens may exert their biological activity in taeniids through the non-specific progesterone receptor membrane component (PGRMC), we harnessed bioinformatics to propose the identity of androgen-regulated proteins and establish their hypothetical physiological role in the parasites. These analyses yield a possible explanation of how androgens exert their cysticidal effects through changes in the expression of proteins involved in cytoskeletal rearrangement, dynamic vesicular traffic and transduction of intracellular signals.

Longitudinal study for anthelmintic efficacy against intestinal helminths in naturally exposed Lithuanian village dogs: critical analysis of feasibility and limitations.

The efficacy of anthelmintic treatment at 1, 3, and 6 month intervals was evaluated in a prospective controlled field study with naturally exposed Lithuanian village dogs by monthly coproscopy during 1 year. A placebo-treated control group (C) (n = 202) and groups treated with two broad-spectrum anthelmintics, febantel/pyrantel-embonate/praziquantel (Drontal® Plus, Bayer) (D1, D3, D6; n = 113-117) and emodepside/praziquantel (Profender®, Bayer) (P1, P3, P6; n = 114-119), were included. At the beginning of the study, eggs of Toxocara canis (4.02%) and T. cati (0.44%) identified morphometrically and/or molecularly and eggs of taeniid- (0.78%) and Capillaria-like eggs (5.03%) were present in the feces without significant differences in prevalence between groups. Significant decreases in excretion of T. canis eggs was found 1 month after the treatment with Drontal® Plus in February (D1) and with Profender® in October (P1), November (P1), December (P3), February (P1), and March (P1, P3), as compared to controls in the same months. The incidence of egg excretion per dog at least once a year was significantly lower in group P1 for T. canis (4.24%; p < 0.01) and in groups D1, P1 for taeniid eggs (0%; p < 0.01 and p < 0.001), when compared to controls (16.96 and 6.70%, respectively). A critical analyses of factors possibly responsible for intestinal passage of canine helminth eggs revealed that chained dogs excreted T. canis eggs more frequently 1 month after treatment compared to dogs in pens, particularly from November to March (p = 0.01). The incidence of single detection of T. cati eggs was significantly increased in chained dogs (12.46%) as compared to fenced dogs (1.08%; p = 0.0001).

In vivo treatment with nitazoxanide induces anaerobic metabolism in experimental intraperitoneal cysticercosis.

Taenia crassiceps cysticerci are used as experimental model to study the host-parasite relationship and treatment of cysticercosis. One of the described mode of actions of nitazoxanide (NTZ) is to block the pyruvate ferredoxine oxidoreductase (PFOR) enzyme which is an essential enzyme to the parasite metabolism. The aim of this study was to determine the in vivo influence of one dosage of NTZ on the energetic metabolism of T. crassiceps cysticerci. Thirty days after the intraperitoneal inoculation of T. crassiceps cysticerci, BALB/c mice were orally treated with 7.5 mg/kg of NTZ. The control group was treated with physiologic solution (NaCl 0.9%). After 24 h, the animals were euthanized and the cysticerci were removed, washed, and processed for biochemical analysis. The organic acids detection occurred through high-performance liquid chromatographic and spectrophotometric analysis. While there was no difference in the glucose dosages, it was possible to observe a significant increase in the lactate concentrations and a decrease in the pyruvate concentrations of the NTZ-treated groups when compared to the control group. Also, there was a decrease in the urea and alpha-ketoglutarate concentrations. This probably occurred due to the impairment of the parasite's PFOR and nitroreductases leading an impairment of the mitochondrial aerobic pathways. In conclusion, the in vivo NTZ treatment leads to an increase in the lactic fermentation and to a decrease in the protein catabolism in T. crassiceps cysticerci.

Alternative energy production pathways in Taenia crassiceps cysticerci in vitro exposed to a benzimidazole derivative (RCB20).

Biochemical studies of benzimidazole derivatives are important to determine their mode of action and activity against parasites. The lack of antihelminthic alternatives to treat parasitic infections and albendazole resistance cases make the search for new antiparasitary drugs of utmost importance. The 6-chloro-5-(1-naphthyloxy)-2-(trifluoromethyl)-1H-benzimidazole (RCB20) is a benzimidazole derivative with promising effect. This study evaluated the effect of different concentrations of RCB20 in the alternative energetic pathway of in vitro Taenia crassiceps cysticerci. The parasites were in vitro exposed to 6.5 and 13 µM of RCB20 and albendazole sulfoxide (ABZSO). The quantification of acetate, acetoacetate, ß-hydroxybutyrate, fumarate and propionate was performed by high-performance liquid chromatography. The quantification of urea, creatinine and total proteins was performed by spectrophotometry. The increase in ß-hydroxybutyrate reflects the enhancement of the fatty acid oxidation in the treated groups. Volatile fatty acids secretion, acetate and propionate, was increased in the treated groups. The secretion mechanisms of the treated parasites were impaired due to organic acids increased concentrations in the cysticerci. It is possible to conclude that the metabolic effect on alternative energetic pathways is slightly increased in the parasites treated with RCB20 than the ones treated with ABZSO.

Nitazoxanide induces in vitro metabolic acidosis in Taenia crassiceps cysticerci.

Nitazoxanide (NTZ) is a broad-spectrum anti-parasitic drug used against a wide variety of protozoans and helminthes. Albendazole, its active metabolite albendazole sulfoxide (ABZSO), is one of the drugs of choice to treat both intestinal and tissue helminth and protozoan infections. However little is known regarding their impact on the metabolism of parasites. The aim of this study was to compare the in vitro effect of NTZ and ABZSO in the glycolysis of Taenia crassiceps cysticerci. The cysticerci were treated with 1.2; 0.6; 0.3 or 0.15 µg/mL of NTZ or ABZSO. Chromatographic and spectrophotometric analyses were performed in the culture medium and in the cysticerci extract. Regarding the glucose concentrations was possible to observe two responses: impair of the uptake and gluconeogenesis. The pyruvate concentrations were increased in the ABZSO treated group. Lactate concentrations were increased in the culture medium of NTZ treated groups. Therefore it was possible to infer that the metabolic acidosis was greater in the group treated with NTZ than in the ABZSO treated group indicating that this is one of the modes of action used by this drug to induce the parasite death.

Acute visceral cysticercosis by Taenia hydatigena in lambs and treatment with praziquantel.

An acute outbreak of Taenia hydatigena cysticercosis, causing mortality in 5 of 21 (23.8%) female lambs, is reported. Gross post-mortem examinations and histology showed Cysticercus tenuicollis as the cause of death. Biochemical parameters in infected lambs confirmed severe hepatitis. Praziquantel, given once at 15 mg/kg body weight (bw), was administered and a dramatic improvement in the clinical condition and biochemical parameters was observed up to 30 days following treatment.

Partial reverse of the TCA cycle is enhanced in Taenia crassiceps experimental neurocysticercosis after in vivo treatment with anthelminthic drugs.

Neurocysticercosis (NCC) is the most common helminthic infection and neglected disease of the central nervous system. It is the leading cause of acquired epilepsy and seizures worldwide. Therefore, to study this important neglected disease, it is important to use experimental models. There is no report in the literature on how the parasite's metabolism reacts to antihelminthic treatment when it is still within the central nervous system of the host. Therefore, the aim of this study was to investigate the energetic metabolism of cysticerci experimentally inoculated in the encephala of BALB/c mice after treatment with low dosages (not sufficient to kill the parasite) of albendazole (ABDZ) and praziquantel (PZQ). BALB/c mice were intracranially inoculated with Taenia crassiceps cysticerci and, after 30 days, received treatment with low dosages of ABDZ and PZQ. After 24 h of treatment, the mice were euthanized, and the cysticerci were removed and analyzed through high-performance liquid chromatography (HPLC) to quantify the organic acids related to the energetic metabolism of the parasite. The partial reverse of the TCA cycle was enhanced by the ABDZ and PZQ treatments both with the higher dosage, as the organic acids of this pathway were significantly increased when compared to the control group and to the other dosages. In conclusion, it was possible to detect the increase of this pathway in the parasites that were exposed to low dosages of ABDZ and PZQ, as it is a mechanism that would amplify the energy production in a hostile environment.

Helminth-derived molecules improve 5-fluorouracil treatment on experimental colon tumorigenesis.

Colorectal cancer (CRC) is one of the most prevalent fatal neoplasias worldwide. Despite efforts to improve the early diagnosis of CRC, the mortality rate of patients is still nearly 50%. The primary treatment strategy for CRC is surgery, which may be accompanied by chemotherapy and radiotherapy. The conventional and first-line chemotherapeutic agent utilized is 5-fluorouracil (5FU). However, it has low efficiency. Combination treatment with leucovorin and oxaliplatin or irinotecan improves the effectiveness of 5FU therapy. Unfortunately, most patients develop drug resistance, leading to disease progression. Here, we evaluated the effect of a potential alternative adjuvant treatment for 5FU, helminth-derived Taenia crassiceps (TcES) molecules, on treating advanced colitis-associated colon cancer. The use of TcES enhanced the effects of 5FU on established colonic tumors by downregulating the expression of the immunoregulatory cytokines, Il-10 and Tgf-ß, and proinflammatory cytokines, Tnf-α and Il-17a, and reducing the levels of molecular markers associated with malignancy, cyclin D1, and Ki67, both involved in apoptosis inhibition and the signaling pathway of ß-catenin. TcES+5FU therapy promoted NK cell recruitment and the release of Granzyme B1 at the tumor site, consequently inducing tumor cell death. Additionally, it restored P53 activity which relates to decreased Mdm2 expression. In vitro assays with human colon cancer cell lines showed that therapy with TcES+5FU significantly reduced cell proliferation and migration by modulating the P53 and P21 signaling pathways. Our findings demonstrate, for the first time in vivo, that helminth-derived excreted/secreted products may potentiate the effect of 5FU on established colon tumors.

Quantitative screening for anticestode drugs based on changes in baseline enzyme secretion by Taenia crassiceps.

Neurocysticercosis (NCC), an infection of the brain with the larval stage of the Taenia solium tapeworm, is responsible for an estimated one-third of adult-onset epilepsy cases in regions of the world where it is endemic. Currently, anthelmintic drugs used for treatment of NCC are only partially effective, and there is, therefore, a pressing need for new therapeutic agents. Discovery of new anthelmintics with activity against T. solium has been limited by the lack of suitable sensitive assays that allow high-throughput screening. Using an in vitro culture system with Taenia crassiceps metacestodes, we demonstrate that changes in secretion of parasite-associated alkaline phosphatase (AP) and phosphoglucose isomerase (PGI) can be used to detect and quantify anthelmintic effects of praziquantel (PZQ), a drug with activity against T. solium. We applied two enzyme release assays to screen for anti-T. crassiceps activity in nonconventional antiparasitic drugs and demonstrate that nitazoxanide and artesunate induced release of both AP and PGI in differing time- and dose-related patterns. Furthermore, imatinib, a tyrosine kinase inhibitor previously reported to have parasiticidal activity against Schistosoma mansoni, also induced release of both AP and PGI in a dose-dependent manner, similar in pattern to that observed with the other anthelmintics. We also evaluated release of ATP into cyst supernatants as an indicator of drug effects but did not see any differences between treated and untreated cysts. These data provide the basis for rapid and quantitative screening assays for testing for anthelmintic activity in candidate anticestode agents.

Steroid synthesis by Taenia crassiceps WFU cysticerci is regulated by enzyme inhibitors.

Cysticerci and tapeworms from Taenia crassiceps WFU, ORF and Taenia solium synthesize sex-steroid hormones in vitro. Corticosteroids increase the 17ß-estradiol synthesis by T. crassiceps cysticerci. T. crassiceps WFU cysticerci synthesize corticosteroids, mainly 11-deoxycorticosterone (DOC). The aim of this work was to investigate whether classical steroidogenic inhibitors modify the capacity of T. crassiceps WFU cysticerci to synthesize corticosteroids and sex steroid hormones. For this purpose, T. crassiceps WFU cysticerci were obtained from the abdominal cavity of mice, pre-cultured for 24h in DMEM+antibiotics/antimycotics and cultured in the presence of tritiated progesterone ((3)H-P4), androstendione ((3)H-A4), or dehydroepiandrosterone ((3)H-DHEA) plus different doses of the corresponding inhibitors, for different periods. Blanks with the culture media adding the tritiated precursors were simultaneously incubated. At the end of the incubation period, parasites were separated and media extracted with ether. The resulting steroids were separated by thin layer chromatography (TLC). Data were expressed as percent transformation of the tritiated precursors. Results showed that after 2h of exposure of the cysticerci to 100 µM formestane, the (3)H-17ß-estradiol synthesis from tritiated androstenedione was significantly inhibited. The incubation of cysticerci in the presence of (3)H-DHEA and danazol (100 nM) resulted in (3)H-androstenediol accumulation and a significant reduction of the 17ß-estradiol synthesis. The cysticerci (3)H-DOC synthesis was significantly inhibited when the parasites were cultured in the presence of different ketoconazole dosis. The drug treatments did not affect parasite's viability. The results of this study showed that corticosteroid and sex steroid synthesis in T. crassiceps WFU cysticerci can be modified by steroidogenic enzyme inhibitors. As was shown previously by our laboratory and others, parasite survival and development depends on sex steroids, therefore the inhibition of their synthesis is a good starting point exploited in situations where the inhibition of steroidogenesis could help to control the infection for the development of new treatments, or replacement of the usual therapy in resistant parasite infections. We raise the possibility that these drug actions may be beneficially.

RCB20, an experimental benzimidazole derivative, affects tubulin expression and induces gross anatomical changes in Taenia crassiceps cysticerci.

Helminth ß-tubulins are the targets of benzimidazole (BZM) carbamate compounds. The specificity of the interactions between such compounds and their in vivo targets depends on the presence of specific amino acid residues in the target molecules. To discover new and effective anthelmintic drugs, we used a medicinal chemistry approach to synthesize a series of BZM derivatives that exploited the BZM moiety as a template. We have previously found that one compound, 2-(trifluoromethyl)-1H-benzimidazole (RCB20), has better in vitro and in vivo activity than albendazole sulfoxide (ABZSO). In the present study, the effect of RCB20 and ABZSO treatment on expression of Taenia crassiceps cysticerci cytoskeletal proteins such as actin, myosin II, and tubulin isoforms was examined. The effects of RCB20 and ABZSO after 11 days treatment of the parasites was evaluated by light, confocal, and electron microscopy, and by immunochemistry and immunohistochemistry. The RCB20-induced effects were more rapid than the ABZSO-induced effects on the parasites. In the RCB20-treated parasites, we observed gross-structural damage at the whole parasite level, particularly in the inner tissues and flame cells. Changes in the expression patterns of the cytoskeletal proteins, as assessed by immunohistochemistry and immunoblotting, revealed that the most important drug-induced effect on the parasites was a reduction in the expression level of tyrosinated α-tubulins. Our research findings suggest that RCB20 treatment affected posttranslational modification of parasite α-tubulin molecules, which involved removal of the α-tubulin carboxy-terminal tyrosine.

In vivo albendazole treatment of Taenia crassiceps cysticerci strain WFU: proliferation, damage, and recovery.

Taenia crassiceps has been widely experimented as a model for in vitro and in vivo studies on drug responses. The purpose of this study was to treat BALB/c mice infected with T. crassiceps strain WFU with commercially available albendazole and to analyze the reduction in parasite infrapopulations. Here, we describe the reduction and apparent damage of T. crassicceps WFU cysticerci in infected mice after antihelminthic drug treatment and subsequent inoculation of those treated parasites into a naïve host. We were able to reduce significantly the parasite counts to 33 and 48% after albendazole treatment for 20 or 25 days and compared with the untreated mice. We also observed morphological damage such as the partial blebbing in the tegument and parenchyma of treated parasites, as well as disorganized musculature and the loss of cell membranes in subtegumental tissue section. However, larvae from albendazole-treated mice inoculated into the next host were able to become re-established in the next murine host due, probably, to the survival of proliferative parasite cells.

The effect of glucocorticoids on sex steroid synthesis in cultured Taenia crassiceps Wake Forest University (WFU) cysticerci.

We have shown previously that cultured Taenia crassiceps Wake Forest University (WFU) and Taenia solium cysticerci, as well as the adult worms, synthesize sex steroid hormones from [3H]steroid precursors and that androgens and oestrogens influence the in vitro development of the parasites. Glucocorticoids (GCs) are used to control the inflammation caused by T. solium cysticerci in the brain. These steroids stimulate oestrogen synthesis in several tissues. Since there is no information on the effect of GC on the endocrine function of cysticerci, we investigated the effect of natural and synthetic GCs on the synthesis of oestrogens in cultured T. crassiceps WFU cysticerci. The cysticerci were obtained from the peritoneal cavity of infected female BALB/c mice; the cysts were washed extensively and pre-cultured in Dulbecco's Modified Eagle's Medium (DMEM) plus antibiotics for 5 days. The parasites were further cultured with different doses of corticosterone, dexamethasone or the vehicle for 5 days. [3H]Dehydroepiandrosterone (3H-DHEA) was added to the media and the cysticerci were further incubated for 6 or 24 h. Media were then removed and the steroids ether-extracted. Aliquots of the media were seeded on silica gel plates and developed in solvent systems. Parasites incubated in the presence of 3H-DHEA synthesized [3H]androstenediol, [3H]testosterone and [3H]17ß-oestradiol ([3H]17ß-E2). The addition of 100 nm or higher corticosterone doses to the media increased [3H]17ß-E2 synthesis fourfold after 24 h. Dexamethasone also increased [3H]17ß-E2 synthesis. The experiments presented here show for the first time that corticosterone and the synthetic GC dexamethasone modulate the synthesis of oestrogens by cysticerci.

Alterations in Taenia crassiceps cysticerci cytoskeleton induced by nitazoxanide and flubendazole.

Cysticercosis is the presence of Taenia solium larval stage in tissues such as central nervous system, skin, muscles and eye globe. The current treatment is based on albendazole and praziquantel which already present resistance reports. Therefore, the search for alternative treatments is paramount. The aim of this study was to determine the effect of flubendazole and nitazoxanide on cytoskeleton proteins from Taenia crassiceps cysticerci, an experimental model for cysticercosis. Cysticerci were cultured in RPMI supplemented medium containing nitazoxanide and/or flubendazole. 24 h after the exposure the cysticerci were processed for scanning and transmission electron microscopy and for protein analysis of the cytoskeleton. The proteins were detected through 1D electrophoresis and identified through Western Blot. Nitazoxanide exposure increased tubulin and actin quantifications in T. crassiceps cysticerci. While flubendazole alone and the drugs combinations induced an increase in α-tubulin and actin and decreased ß-tubulin quantifications in the parasite. Morphological changes such as swelling and rupture of vesicle, stiff membrane, decrease in movements were observed when the cysticerci were incubated with the different compounds. In conclusion the drugs induced significative impact in the parasite`s cytoskeleton and may be considered as alternative treatments for cysticercosis.