In Vitro and In Vivo Cysticidal Effects of Carica Papaya Cell Suspensions.

Parasitic diseases are a major public health problem worldwide. Plant-derived products appear to be ideal candidates from a biotechnological perspective, being sustainable and environmentally friendly. The antiparasitic properties of Carica papaya have been attributed to some of its components, including papain and other compounds that are concentrated in the latex and seeds. This study demonstrated in vitro a high and insignificantly different cysticidal activity of soluble extract that was obtained after the disruption of nontransformed wild-type (WT) cells as well as transformed papaya calluses (PC-9, PC-12, and PC-23) and papaya cell suspensions (CS-9, CS-12, and CS-23). In vivo, cell suspensions of CS-WT and CS-23 that had been previously lyophilized were tested with respect to their cysticidal effects, compared with those of three commercial antiparasitic drugs. CS-WT and CS-23 together reduced the number of cysticerci, the number of buds, and the percentage of calcified cysticerci in a similar extent to albendazole and niclosamide, whereas ivermectin was less effective. Mice were then orally immunized with CS-23 that expressed the anti-cysticercal KETc7 antigen (10 µg/mouse), CS-WT (10 mg/mouse), or both together to evaluate their preventive properties. CS-23 and CS-WT significantly reduced the expected parasite and increased the percentage of calcified cysticerci as well as recovery, being more effective when employed together. The results reported in this study support the feasibility of the development of an anti-cysticercosis vaccine from cells of C. papaya in in vitro cultures, as they are a source of an anthelmintic, natural, and reproducible product.

Diagnostic value of glycoprotein band patterns of three serologic enzyme-linked immunoelectrotransfer blot assays for neurocysticercosis.

The enzyme-linked immunoelectrotransfer blot (EITB) assay to detect antibodies in serum is a complementary tool for the diagnosis of neurocysticercosis (NCC). Presence of at least one glycoprotein band corresponding to a Taenia solium (T. solium) antigen indicates a positive result; however, EITB assays have multiple glycoprotein bands, and previous work has suggested that band patterns may have additional diagnostic value. We included 58 participants with a definitive diagnosis of NCC who received care at the Instituto Nacional de Neurología y Neurocirugía in Mexico City. Three different EITB tests were applied to participants' serum samples (LDBio, France; US Centers for Disease Control and Prevention [CDC]; and Instituto de Diagnóstico y Referencia Epidemiológicos [InDRE]). There was substantial variability in specific glycoprotein band patterns among the three assays. However, in age- and sex-adjusted logistic regression models, the number of glycoprotein bands was positively associated with the presence of vesicular extraparenchymal cysts (InDRE adjusted odds ratio [aOR] 1.60 p < 0.001; CDC aOR 6.31 p < 0.001; LDBio aOR 2.45 p < 0.001) and negatively associated with the presence of calcified parenchymal cysts (InDRE aOR 0.63 p < 0.001; CDC aOR 0.25 p < 0.001; LDBio aOR 0.44 p < 0.001). In a sensitivity analysis also adjusting for cyst count, results were similar. In all three EITB serum antibody tests, the number of glycoprotein bands consistently predicted cyst stage and location, although magnitude of effect differed.

Expression of Dopamine Receptors in Immune Regulatory Cells.

OBJECTIVE: Parkinson's disease (PD) patients are usually treated with L-dopa and/or dopaminergic agonists, which act by binding five types of dopaminergic receptors (DRD1-DRD5). Peripheral immune cells are known to express dopamine receptors on their membrane surface, and therefore they could be directly affected by the treatment. Regulatory cells are the main modulators of inflammation, but it is not clear whether dopaminergic treatment could affect their functions. While only regulatory T cells (Tregs) have been proved to express dopamine receptors, it is not known whether other regulatory cells such as CD8regs, regulatory B cells (Bregs), tolerogenic dendritic cells, and intermediate monocytes also express them. METHODS: The expression of dopamine receptors in Tregs, CD8regs, Bregs, tolerogenic dendritic cells, and intermediate monocytes was herein evaluated. cDNA from 11 PD patients and 9 control subjects was obtained and analyzed. RESULTS: All regulatory cell populations expressed the genes coding for dopamine receptors, and this expression was further corroborated by flow cytometry. These findings may allow us to propose regulatory populations as possible targets for PD treatment. CONCLUSIONS: This study opens new paths to deepen our understanding on the effect of PD treatment on the cells of the regulatory immune response.

Immunodiagnosis of human neurocysticercosis: comparative performance of serum diagnostic tests in Mexico.

Immunodiagnosis has a supportive role in the diagnosis of neurocysticercosis (NCC). The aim of this study was to compare the validity of seven immunodiagnostic tests among serum samples from 58 patients with NCC, 26 patients with neurological diseases other than NCC, and 15 healthy controls. One test for viable parasite detection (HP10 antigen assay) and six for antibody detection were evaluated. For the entire sample, sensitivities ranged from 55.2% (NOVALISA) to 81.0% (enzyme-linked immunosorbent assay [ELISA] Taenia solium antibody), with the sensitivity of the latter test significantly higher than that of the in-house ELISA Taenia crassiceps, NOVALISA, enzyme-linked immunoelectrotransfer blot (EITB) CDC, and HP10. Overall, specificities were high, ranging from 85.4% (ELISA Ts) to 97.1% (NOVALISA), with no statistically significant differences. Detection of HP10 antigen was significantly associated with the presence of vesicular parasites. The simple and low-cost ELISA Taenia solium antibody Ab instead of EITB is recommended to support NCC diagnosis in both rural and hospital settings in Mexico.

Treatment-Resistant Human Extraparenchymal Neurocysticercosis: An Immune-Inflammatory Approach to Cysticidal Treatment Outcome.

OBJECTIVE: The aim of this study is to analyze the immune-endocrine profile in neurocysticercosis (NC) patients resistant to cysticidal treatment. METHODS: The inflammatory and regulatory responses of 8 resistant NC patients with extraparenchymal parasites and 5 healthy controls were evaluated through flow cytometry. Serum interleukin levels were measured by ELISA and catecholamines levels by high performance liquid chromatography. RESULTS: Higher percentages of Tr1, CD4+CD25+FOXP3+CD127- and CD4+CD45RO+FOXP3HI were found in NC patients compared with healthy controls, but no difference was found in catecholamine levels. Antigen-specific proliferative immune response was observed in NC patients. Neither anti-inflammatory nor pro-inflammatory cytokines showed differences between patients and controls, but IL-6 levels were lower in treatment-resistant NC patients. In addition, TGFß showed a significant negative correlation with dopamine. CONCLUSIONS: Altogether, these results may point to a modulation of the neuroinflammation in these patients that could indirectly favor cysticercal survival in CNS microenvironment.

Experimental and Theoretical Approaches To Investigate the Immunogenicity of Taenia solium-Derived KE7 Antigen.

Taenia solium cysticercosis, a parasitic disease that affects human health in various regions of the world, is preventable by vaccination. Both the 97-amino-acid-long KETc7 peptide and its carboxyl-terminal, 18-amino-acid-long sequence (GK-1) are found in Taenia crassiceps Both peptides have proven protective capacity against cysticercosis and are part of the highly conserved, cestode-native, 264-amino-acid long protein KE7. KE7 belongs to a ubiquitously distributed family of proteins associated with membrane processes and may participate in several vital cell pathways. The aim of this study was to identify the T. solium KE7 (TsKE7) full-length protein and to determine its immunogenic properties. Recombinant TsKE7 (rTsKE7) was expressed in Escherichia coli Rosetta2 cells and used to obtain mouse polyclonal antibodies. Anti-rTsKE7 antibodies detected the expected native protein among the 350 spots developed from T. solium cyst vesicular fluid in a mass spectrometry-coupled immune proteomic analysis. These antibodies were then used to screen a phage-displayed 7-random-peptide library to map B-cell epitopes. The recognized phages displayed 9 peptides, with the consensus motif Y(F/Y)PS sequence, which includes YYYPS (named GK-1M, for being a GK-1 mimotope), exactly matching a part of GK-1. GK-1M was recognized by 58% of serum samples from cysticercotic pigs with 100% specificity but induced weak protection against murine cysticercosis. In silico analysis revealed a universal T-cell epitope(s) in native TsKE7 potentially capable of stimulating cytotoxic T lymphocytes and helper T lymphocytes under different major histocompatibility complex class I and class II mouse haplotypes. Altogether, these results provide a rationale for the efficacy of the KETc7, rTsKE7, and GK-1 peptides as vaccines.

Transgenic papaya: a useful platform for oral vaccines.

MAIN CONCLUSION: Transgenic papaya callus lines expressing the components of the S3Pvac vaccine constitute a stable platform to produce an oral vaccine against cysticercosis caused by Taenia solium or T. crassiceps. The development of effective delivery systems to cope with the reduced immunogenicity of new subunit vaccines is a priority in vaccinology. Herein, experimental evidence supporting a papaya-based platform to produce needle-free, recombinant, highly immunogenic vaccines is shown. Papaya (Carica papaya) callus lines were previously engineered by particle bombardment to express the three protective peptides of the S3Pvac anti-cysticercosis vaccine (KETc7, KETc12, KETc1). Calli were propagated in vitro, and a stable integration and expression of the target genes has been maintained, as confirmed by PCR, qRT-PCR, and HPLC. These results point papaya calli as a suitable platform for long-term transgenic expression of the vaccine peptides. The previously demonstrated protective immunogenic efficacy of S3Pvac-papaya orally administered to mice is herein confirmed in a wider dose-range and formulated with different delivery vehicles, adequate for oral vaccination. This protection is accompanied by an increase in anti-S3Pvac antibody titers and a delayed hypersensitivity response against the vaccine. A significant increase in CD4+ and CD8+ lymphocyte proliferation was induced in vitro by each vaccine peptide in mice immunized with the lowest dose of S3Pvac papaya (0.56 ng of the three peptides in 0.1 µg of papaya callus total protein per mouse). In pigs, the obliged intermediate host for Taenia solium, S3Pvac papaya was also immunogenic when orally administered in a two-log dose range. Vaccinated pigs significantly increased anti-vaccine antibodies and mononuclear cell proliferation. Overall, the oral immunogenicity of this stable S3Pvac-papaya vaccine in mice and pigs, not requiring additional adjuvants, supports the interest in papaya callus as a useful platform for plant-based vaccines.

Towards the development of an oral vaccine against porcine cysticercosis: expression of the protective HP6/TSOL18 antigen in transgenic carrots cells.

MAIN CONCLUSION: The Taenia solium HP6/TSOL18 antigen was produced in carrot cells, yielding an immunogenic protein that induced significant protection in an experimental murine model against T. crassiceps cysticercosis when orally administered. This result supports the potential of HP6/TSOL18-carrot as a low-cost anti-cysticercosis vaccine candidate. Cysticercosis is a zoonosis caused by Taenia solium that can be prevented by interrupting the parasite life cycle through pig vaccination. Several injectable vaccine candidates have been reported, but the logistic difficulties and costs for its application limited its use in nationwide control programs. Oral plant-based vaccines can deal with this limitation, because of their easy administration and low cost. A stable expression of the HP6/TSOL18 anti-T. solium cysticercosis protective antigen in carrot calli transformed with an optimized transgene is herein reported. An antigen accumulation up to 14 µg g(-1) of dry-weight biomass was achieved in the generated carrot lines. Mouse immunization with one of the transformed calli induced both specific IgG and IgA anti-HP6/TSOL18 antibodies. A statistically significant reduction in the expected number of T. crassiceps cysticerci was observed in mice orally immunized with carrot-made HP6/TSOL18, in a similar extent to that obtained by subcutaneous immunization with recombinant HP6/TSOL18 protein. In this study, a new oral plant-made version of the HP6/TSOL18 anti-cysticercosis vaccine is reported. The vaccine candidate should be further tested against porcine cysticercosis.

Behavioral and hormonal changes associated with the infective dose in experimental taeniasis in golden hamsters (Mesocricetus auratus).

INTRODUCTION: It has been reported that behavioral changes relate to infection in different parasitoses. However, the relation between the extent of the behavioral changes and the magnitude of the infection has been scarcely studied. The aim of this study was to evaluate the relationship between different doses of infection and the behavioral changes induced in the experimental Taenia pisiformis taeniasis in golden hamsters. METHODS: Groups of nine hamsters were infected with three or six T. pisiformis metacestodes. The locomotor activity was quantified daily in an open field test during the 21 days after infection; anxiety test was performed in an elevated plus-maze with a dark/light area at 7, 14 and 21 days post-infection, and serum cortisol levels were determined by radioimmunoassay before infection and at day 22 after infection. RESULTS: The challenge itself induced modifications on behavior and cortisol levels in hamsters, with or without successful infection (taenia development). Animals challenged with three metacestodes induced a decrease in locomotor activity and an increase in anxiety in infected animals. A higher and earlier decrease in locomotor activity and increased anxiety levels were observed in hamsters challenged with six cysticerci, which were accompanied by higher levels of sera cortisol at the end of the experiment. At necropsy, 44-55% of hamster became infected with an efficiency of implantation of 22-26%, challenged with three or six cysticerci respectively. CONCLUSION: The challenge of hamsters with metacestodes, promote behavioral changes in an extent dependent on the magnitude of the challenge, disregarding the effectiveness of the infection.

Neurocysticercosis: the effectiveness of the cysticidal treatment could be influenced by the host immunity.

Neurocysticercosis, a clinically and radiologically pleomorphic parasitic disease, is still endemic to most non-developed countries of Latin America, Africa, and Asia. Anti-helminthic drugs (AHD) are generally effective and rapidly destroy parenchymal cysticerci. In contrast, several cycles of AHD are frequently necessary to damage extraparenchymally located parasites. The present study was designed to evaluate whether differences in the immunological profile of the patients is involved in the diversity of the response to AHD. To this end, a global gene expression microarray and a cytokine analysis were made. Responder patients were those showing a radiological reduction greater than 50 % in the parasite burden following AHD treatment. Microarray pre- and post-treatment comparisons showed that a total of eighteen immune-related genes were up-regulated in the five responder patients with respect the expression profile seen in the four non-responder subjects. The function of up-regulated genes exerted pro-inflammatory (RORγC, Sema4A, SLAMF3, SLAMF6), anti-inflammatory (TGFß, TNFRSF25, TNFRS18, SLAMF1, ILF2), or immunomodulatory effects (CXCL2, RUNX3, SLAMF9, TGFBR3). To further explore the causes of the heterogeneity in the response to treatment, a wide ELISA cytokine analysis was performed in serum, PBMC supernatants, and CSF samples from 39 responder and 26 non-responder patients. Responder patients showed higher CSF IL-17A levels (P = 0.04) and higher supernatant IL-6 levels (P = 0.03) 60 days after treatment. These results suggest a possible influence of pro-inflammatory cytokines on the response to AHD as observed by radiological methods, and thus the possible participation of the host immunity in the effectiveness of AHD treatment.

Epidemiology of swine cysticercosis in two rural communities of Zacapa, Guatemala.

Taeniasis/cysticercosis complex caused by Taenia solium, is a serious public health problem and causes major economic losses to swine producers in developing countries in Asia, Africa and the Americas. Despite scarce epidemiological data, Guatemala is considered endemic for T. solium. A cross-sectional study was conducted in Azacualpa and Malpais, two villages in the department of Zacapa, to assess the prevalence of swine cysticercosis and associated factors. Between March and October 2019, 149 pigs were examined by tongue palpation and serum samples were then collected to detect antibodies by ab-ELISA, and necropsy was performed on pigs that were positive by tongue palpation and/or ab-ELISA, to assess parasite load. Pig owners were asked to fill out a questionnaire on factors related to pig husbandry and occurrence of swine cysticercosis. Pearson's chi-square test and multivariate analysis were used to measure the association between serological results and other variables (p < 0.05 was considered significant). The seroprevalence of swine cysticercosis was 13.4% (13/97, 95% C.I. 6.6%-20.2%) and 25% (13/52, 95% C.I. 13.2%-36.8%) in Azacualpa and Malpais, respectively, yielding an overall seroprevalence of 17.4% (26/149, 95% C.I. 11.4%-23.5%). Parasite loads ranged from 1 to over 23,000 metacestodes per carcass. No bivariate association was found between exposure variables and seropositivity. A positive diagnosis by tongue palpation increased the odds of finding pigs seropositive for cysticercosis by a factor of 16.1 in the multivariate analysis. Despite the high prevalence and parasite load of T. solium, risk factors associated with cysticercosis were not significant in this study.

Intranasal Versus Intravenous Dexamethasone to Treat Hospitalized COVID-19 Patients: A Randomized Multicenter Clinical Trial.

BACKGROUND: SARS-CoV2 induces flu-like symptoms that can rapidly progress to severe acute lung injury and even death. The virus also invades the central nervous system (CNS), causing neuroinflammation and death from central failure. Intravenous (IV) or oral dexamethasone (DXM) reduced 28 d mortality in patients who required supplemental oxygen compared to those who received conventional care alone. Through these routes, DMX fails to reach therapeutic levels in the CNS. In contrast, the intranasal (IN) route produces therapeutic levels of DXM in the CNS, even at low doses, with similar systemic bioavailability. AIMS: To compare IN vs. IV DXM treatment in hospitalized patients with COVID-19. METHODS: A controlled, multicenter, open-label trial. Patients with COVID-19 (69) were randomly assigned to receive IN-DXM (0.12 mg/kg for three days, followed by 0.6 mg/kg for up to seven days) or IV-DXM (6 mg/d for 10 d). The primary outcome was clinical improvement, as defined by the National Early Warning Score (NEWS) ordinal scale. The secondary outcome was death at 28 d between IV and IN patients. Effects of both treatments on biochemical and immunoinflammatory profiles were also recorded. RESULTS: Initially, no significant differences in clinical severity, biometrics, and immunoinflammatory parameters were found between both groups. The NEWS-2 score was reduced, in 23 IN-DXM treated patients, with no significant variations in the 46 IV-DXM treated ones. Ten IV-DXM-treated patients and only one IN-DXM patient died. CONCLUSIONS: IN-DMX reduced NEWS-2 and mortality more efficiently than IV-DXM, suggesting that IN is a more efficient route of DXM administration.

Genetic variation in the Cytb gene of human cerebral Taenia solium cysticerci recovered from clinically and radiologically heterogeneous patients with neurocysticercosis.

Neurocysticercosis (NC) is a clinically and radiologically heterogeneous parasitic disease caused by the establishment of larval Taenia solium in the human central nervous system. Host and/or parasite variations may be related to this observed heterogeneity. Genetic differences between pig and human-derived T. solium cysticerci have been reported previously. In this study, 28 cysticerci were surgically removed from 12 human NC patients, the mitochondrial gene that encodes cytochrome b was amplified from the cysticerci and genetic variations that may be related to NC heterogeneity were characterised. Nine different haplotypes (Ht), which were clustered in four haplogroups (Hg), were identified. Hg 3 and 4 exhibited a tendency to associate with age and gender, respectively. However, no significant associations were found between NC heterogeneity and the different T. solium cysticerci Ht or Hg. Parasite variants obtained from patients with similar NC clinical or radiological features were genetically closer than those found in groups of patients with a different NC profile when using the Mantel test. Overall, this study establishes the presence of genetic differences in the Cytb gene of T. solium isolated from human cysticerci and suggests that parasite variation could contribute to NC heterogeneity.

Taenia solium taeniasis/cysticercosis in Guatemala: a prevalent public health problem?

In Guatemala, neurocysticercosis (NCC) was first recognized in 1940; since then, cases of NCC have been reported in all Guatemalan departments. However, epidemiological studies on Taenia solium infections are scarce and most information remains unpublished. This study aims to provide evidence of T. solium infections as a public health problem in Guatemala. All information available, either published or unpublished, on T. solium infections in the country was compiled. Official data from the Ministry of Health for the period 2003-2019 were reviewed and analyzed, and all cases of T. solium infections were classified and counted. In total, 5246 cases of taeniasis and 454 cases of human cysticercosis were recorded. On the other hand, 44 studies were identified, mostly from local journals, which included 1951 cases of taeniasis, 2873 cases of human cysticercosis of which 543 were classified with complete diagnosis, and 2590 cases of porcine cysticercosis. Cases were classified by geographic region, patient sex, and Taenia species in taeniasis cases when information was available, and the departments with the highest number of taeniasis and cysticercosis cases were identified. Meanwhile, in Zacapa, a northeastern department of Guatemala with one the highest number of taeniasis cases, a young man diagnosed with a severe form of NCC and two cases of porcine cysticercosis (both confirmed by necropsy) were identified. Taken together, the data herein reported indicate that T. solium infections are a major health problem in Guatemala that needs to be addressed.

Standardizing an Experimental Murine Model of Extraparenchymal Neurocysticercosis That Immunologically Resembles Human Infection.

BACKGROUND: Neurocysticercosis (NCC) is endemic in non-developed regions of the world. Two forms of NCC have been described, for which neurological morbidity depends on the location of the lesion, which can be either within the cerebral parenchyma or in extraparenchymal spaces. The extraparenchymal form (EXP-NCC) is considered the most severe form of NCC. EXP-NCC often requires several cycles of cysticidal treatment and the concomitant use of glucocorticoids to prevent increased inflammation, which could lead to intracranial hypertension and, in rare cases, to death. Thus, the improvement of EXP-NCC treatment is greatly needed. METHODS: An experimental murine model of EXP-NCC, as an adequate model to evaluate new therapeutic approaches, and the parameters that support it are described. EXP-NCC was established by injecting 30 Taenia crassiceps cysticerci, which are less than 0.5 mm in diameter, into the cisterna magna of male and female Wistar rats. RESULTS: Cyst implantation and infection progression were monitored by detecting the HP10 antigen and anti-cysticercal antibodies in the serum and cerebral spinal fluid (CSF) of infected rats and by magnetic resonance imaging. Higher HP10 levels were observed in CSF than in the sera, as in the case of human EXP-NCC. Low cell recruitment levels were observed surrounding established cysticerci in histological analysis, with a modest increase in GFAP and Iba1 expression in the parenchyma of female animals. Low cellularity in CSF and low levels of C-reactive protein are consistent with a weak inflammatory response to this infection. After 150 days of infection, EXP-NCC is accompanied by reduced levels of mononuclear cell proliferation, resembling the human disease. EXP-NCC does not affect the behavior or general status of the rats. CONCLUSIONS: This model will allow the evaluation of new approaches to control neuroinflammation and immunomodulatory treatments to restore and improve the specific anti-cysticercal immunity in EXP-NCC.

Neurocysticercosis: local and systemic immune-inflammatory features related to severity.

Neurocysticercosis (NC) is caused by the establishment of Taenia solium cysticerci in the central nervous system. Previous studies have established that neuroinflammation plays a key role in the severity of the disease. However, the relationship between peripheral and local immune response remains inconclusive. This work studies the peripheral and local immune-inflammatory features and their relationships, toward the identification of potential peripheral immunologic features related to severity. A panel of cytokines was measured in paired cerebrospinal fluid (CSF) and in the supernatant of antigen-specific stimulated peripheral blood mononuclear cells samples (SN) in a total of 31 untreated inflammatory and non-inflammatory NC patients. Increased clinical and radiologic severity was associated with an increased cerebrospinal fluid cell count. A peripheral proliferative depression that negatively correlates with CSF cellularity and TNFα and that positively correlates with SN IL5 was observed in severe NC patients. These results provide evidences to support the systemic proliferative response as a biomarker to monitor the level of neuroinflammation, of possible value in the patients' follow-up during treatment.

Immunomodulatory activity of diethylcarbamazine on humoral, cellular cytokine response and respiratory burst in BALB/c mice.

Diethylcarbamazine (DEC) is an anthelmintic piperazine derivative drug with putative immunomodulating properties, including increased platelet and granulocyte adhesion to parasites and enhanced production of cytokines. To further analyse these properties in a well-established animal model, we evaluated the effect of DEC on antibody, cellular cytokine response and respiratory burst in BALB/c mice. Animals were challenged with a thymus-dependent (tetanus toxoid, (TT)) and with a thymus-independent (lipopolysaccharide, (LPS)) antigen and treated with DEC for seven days with two different doses (50 mg/day and 500 mg/day). Serum was assessed for antibody production at 0, 4, 7, 14, 21 and 28 days after stimulation and at 0, 24 and 48 h for IL-2, IFN-γ, IL-10 and IL-12 release. Respiratory burst of neutrophils and monocytes from peripheral blood was measured by flow cytometry. We found low-dose treatment with DEC enhanced cytokine production vs. TT and antibody production vs. LPS, whereas a higher dose enhanced significantly the respiratory burst of both polymorphonuclear leukocytes and monocytes, with a significant higher effect on the former. Our results suggest a stimulating, dose-dependent immunomodulatory effect of DEC with a higher effect on the phagocytic cells.

Improvement of cell suspension cultures of transformed and untransformed Carica papaya cell lines, towards the development of an antiparasitic product against the gastrointestinal nematode Haemonchus contortus.

Parasitic diseases have a major impact on human and animal health worldwide. Despite the availability of effective anti-parasitic drugs, their excessive and uncontrolled use has promoted the emergence of drug resistance, severely affecting ecosystems and human health. Thus, developing environmentally friendly antiparasitic treatments is urgently needed. Carica papaya has shown promising effects against infectious diseases. C. papaya embryogenic calluses were genetically modified by our research team to insert immunogenic peptides with the goal of developing an oral anti-cysticercosis vaccine. Among these callus cell lines, one labeled as CF-23, which expresses the KETc7 immunogenic peptide, induced the highest protection levels against experimental cysticercosis. In the process of designing a natural antiparasitic product based on C. papaya that simultaneously induced immunity against cysticercosis, both transformed (SF-23) and untransformed (SF-WT) suspension cultures were produced and optimized. Our results showed a better duplication time (td) for SF-23 (6.9 days) than SF-WT (13.02 days); thus, the SF-23 line was selected for scale-up in a 2-L airlift bioreactor, reaching a td of 4.4 days. This is the first time that a transgenic line of C. papaya has been grown in an airlift bioreactor, highlighting its potential for scale-up cultivation in this type of reactor. Considering the previously reported nematocidal activity of C. papaya tissues, their activity against the nematode Haemonchus contortus of aqueous extracts of SF-WT and SF-23 was explored in this study, with promising results. The information herein reported will allow us to continue the cultivation of the transgenic cell suspension line of C. papaya under reproducible conditions, to develop a new anti-parasitic product.

Pharmacokinetic Study of Intranasal Dexamethasone and Methylprednisolone Compared with Intravenous Administration: Two Open-Label, Single-Dose, Two-Period, Two-Sequence, Cross-Over Study in Healthy Volunteers.

Dexamethasone (DXM) and methylprednisolone (MEP) are potent glucocorticoids used to control several inflammatory conditions. Evidence of delayed DXM reaching the central nervous system (CNS) as well as tachyphylaxis and systemic, undesirable side effects are the main limitations of peripheral delivery. Intranasal administration offers direct access to the brain as it bypasses the blood-brain barrier. The Mucosal Atomization Device is an optimal tool that can achieve rapid absorption into the CNS and the bloodstream across mucosal membranes. This study was designed to evaluate and compare the bioavailability of DXM and MEP after intranasal versus intravenous administration. Two open-label, balanced, randomized, two-treatment, two-period, two-sequence, single-dose, crossover studies were conducted, which involved healthy male and female adult volunteers. After intranasal administration, DXM and MEP were detected in plasma after the first sampling time. Mean peak concentrations of DXM and MEP were 86.61 ng/mL at 60 min and 843.2 ng/mL at 1.5 h post-administration, respectively. DXM and MEP showed high absolute bioavailability, with values of 80% and 95%, respectively. No adverse effects were observed. DXM and MEP systemic bioavailability by intranasal administration was comparable with the intravenous one, suggesting that the intranasal route can be used as a non-invasive and appropriate alternative for systemic drug delivery.

Diethylcarbamazine as potential treatment of COVID-19 lung fibrosis.

Diethylcarbamazine, the antiparasitic drug, also possesses anti-inflammatory and immunomodulatory activities. The anti-fibrotic activity of diethylcarbamazine makes it a potential candidate to treat coronavirus disease 2019 (COVID-19)-related pulmonary fibrosis. Experimental and clinical studies should assess this possible effect.