Immunomodulatory effect of various anti-parasitics: a review

Immunopotentiating effects of herb-partitioned moxibustion on the spleens of cyclophosphamide-induced immunosuppressed rats

BACKGROUND

To investigate the effec of the herb-partitioned moxibustion on T-lymphocyte activity in immunosuppressed rats through differential modulation of the immune checkpoint molecules CD28 and CTLA-4.

METHODS

Forty-eight Sprague‒Dawley rats were randomly divided into the normal group (NG), the cyclophosphamide model group (CTX), the herb-partitioned moxibustion group (HPM), the CD28 inhibitor + herb-partitioned moxibustion group (aCD28 + HPM), the CTLA-4 inhibitor + herb-partitioned moxibustion group (aCTLA-4 + HPM), and the levamisole group (LEV) (8 rats per group). The immunosuppression model was prepared using cyclophosphamide. HPM treatments was performed via herb-partitioned moxibustion at 4 acupoints, Zhongwan (CV12), Shenque (CV8), Guanyuan (CV4), and Zusanli (ST36). Subsequently, the moxa floss was made into a conical moxa cone, which was then placed on the herbal cake and ignited. Five consecutive moxibustion strokes were performed daily for 10 consecutive days. In addition to the same moxibustion, each rat in the aCD28 + HPM group was injected intraperitoneally with 0.5 mg/kg of CD28 inhibitor per rat on the first day of treatment, and 100 μL of CTLA-4 inhibitor was injected into the aCTLA-4 + HPM group on Days 1, 4, and 7. For the positive control, levamisole (LEV) was administered by gavage at a dose of 2 mg/kg once daily for 10 days.

RESULTS

Compared with those in CTX model rats, the WBC counts in the HPM and other groups were significantly higher. The immobility time of EPM in the HPM group was significantly lower than that of the CTX group. The HE stainin results also showed that after treatment, the the marginal zone area of the spleen tissue in the HPM increased, the number of lymphatic sheath lymphocytes around the small central artery of the spleen increased, and the amount of red pulp containing a small amount of pigmentation was partially reduced. Compared with those in the CTX group, the serum levels of CD28, CTLA-4, B7-1, and B7-2 were significantly lower, and the levels of α-MSH, TrkB, and BDNF were significantly greater in the HPM group. The results of the flow cytometry assay showed a significant increase in the number of CD8 + T lymphocytes after treatment with HPM or other agents compared to that in the CTX group. The immunofluorescence results showed that the levels of CD28 and CTLA-4 lower in spleen tissues than in control tissues, and the binding ability of CD28 to B7-1 and B7-2 was weakened after treatment with HPM and other treatments compared with CTX rats, PCR for CD28, CTLA-4 and B7-1 showed similar results.

CONCLUSION

In the immunosuppressive rat model induced by cyclophosphamide, HPM upregulated the expression of α-MSH, TrkB, and BDNF, and downregulated the expression of CD28 and CTLA-4, thereby enhancing the activity of CD8+ T lymphocytes, restoring spleen function, improving the immunosuppressive state, restoring immune function, and effectively alleviating depressive symptoms.

Change in thermal stability and molecular structure characteristics of whey protein beta-lactoglobulin upon the interaction with levamisole hydrochloride

The interaction between beta-lactoglobulin (BLG) and anthelmintic compounds including levamisole (LEV) is a matter of great concern as it not only poses potential health and environmental risks but also has significant implications for food processing and production. The mechanisms of LEV-BLG interaction were investigated through spectral and molecular modeling approaches. Fluorescence and UV-Visible investigations indicated the formation of a spontaneous and stable LEV-BLG complex. Structural changes of BLG were revealed by circular dichroism and Fourier transform infrared studies. The thermal stability of BLG increased in the presence of LEV. Molecular docking studies indicated the best mode of LEV-BLG interaction and molecular dynamics simulation confirmed the stability of the LEV-BLG complex. In conclusion, our study sheds light on the potential of BLG to interact with deleterious substances such as anthelmintic agents, thus highlighting the necessity of further research in this field to assure food safety and prevent any health hazards.

Improved Stability-Indicating RP-UPLC Method for the Levamisole Hydrochloride Assay and Estimation of Its Related Compounds

BACKGROUND

Levamisole hydrochloride (LVM) is an anthelmintic drug substance with immunomodulatory and anticancer activities. LVM has also found usage as a cutting agent in street cocaine.

OBJECTIVE

This study was aimed to develop and validate an alternative and improved stability-indicating reversed-phase ultraperformance liquid chromatography (RP-UPLC) method for the determination of LVM and the estimation of its related compounds.

METHOD

The UPLC method for the assay was optimized in terms of organic solvents consumed, pH, column temperature, and flow rate. Determination of LVM and its related compounds was performed using a gradient elution on a Waters ACQUITY UPLC® BEH C18 (50 mm × 2.1 mm i.d., 130 Å). The column temperature was maintained at 35°C. Mobile phase A was composed of aqueous 5 mM ammonium hydroxide, and mobile phase B was composed of acetonitrile. All the analytes were monitored by UV detection at 215 nm with a flow rate of 0.7 mL/min. The total runtime of the method with column equilibration is 4.0 min.

RESULTS

The developed method met all the acceptance criteria of the current International Council for Harmonization [ICH Q2 (R1)] guidelines. The method was tested in terms of specificity, linearity (R2 > 0.999), limit of detection (LOD; 0.06 μg/mL), limit of quantitation (LOQ; 0.2 μg/mL), accuracy, precision, and robustness. With a short analysis time (<2.5 min) and reduced consumption of organic solvents, the proposed method is considered a greener alternative to conventional chromatographic methods.

CONCLUSIONS

An alternative and improved UPLC method was successfully developed and validated in accordance with the ICH guidelines for the determination of LVM and the estimation of its related compounds.

HIGHLIGHTS

Due to its high degree of selectivity, speed, and accuracy, the developed method can significantly benefit the end-users with laboratory efficiency and throughput during routine analysis of production batches and stability monitoring of LVM-related drug products.

Ivermectin systemic availability in adult volunteers treated with different oral pharmaceutical formulations

Ivermectin (IVM) is currently approved as an antiparasitic agent for human use in the treatment of onchocerciasis, lymphatic filariasis, strongyloidiasis, scabies, and pediculosis. Recent findings indicate that IVM may reach other pharmacological targets, which accounts for its proven anti-inflammatory/immunomodulatory, cytostatic, and antiviral effects. However, little is known about the assessment of alternative drug formulations for human use.

OBJECTIVE

To compare the systemic availability and disposition kinetics of IVM orally administered as different pharmaceutical formulations (tablet, solution, or capsule) to healthy adults.

EXPERIMENTAL DESIGN/MAIN FINDINGS

Volunteers were randomly assigned to 1 of 3 experimental groups and orally treated with IVM as either, a tablet, solution, or capsules at 0.4 mg/kg in a three-phase crossover design. Blood samples were taken as dried blood spots (DBS) between 2 and 48 h post-treatment and IVM was analyzed by HPLC with fluorescence detection. IVM Cmax value was higher (P < 0.05) after the administration of the oral solution compared to treatments with both solid preparations. The oral solution resulted in a significantly higher IVM systemic exposure (AUC: 1653 ng h/mL) compared to the tablet (1056 ng h/mL) and capsule (996 ng h/mL) formulations. The simulation of a 5-day repeated administration for each formulation did not show a significant systemic accumulation.

CONCLUSION

Beneficial effects against systemically located parasitic infections as well as in any other potential therapeutic field of IVM application would be expected from its use in the form of oral solution. This pharmacokinetic-based therapeutic advantage without the risk of excessive accumulation needs to be corroborated in clinical trials specifically designed for each purpose.

A cellular and molecular biology-based update for ivermectin against COVID-19: is it effective or non-effective?

Despite community vaccination against coronavirus disease 2019 (COVID-19) and reduced mortality, there are still challenges in treatment options for the disease. Due to the continuous mutation of SARS-CoV-2 virus and the emergence of new strains, diversity in the use of existing antiviral drugs to combat the epidemic has become a crucial therapeutic chance. As a broad-spectrum antiparasitic and antiviral drug, ivermectin has traditionally been used to treat many types of disease, including DNA and RNA viral infections. Even so, based on currently available data, it is still controversial that ivermectin can be used as one of the effective antiviral agents to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or not. The aim of this study was to provide comprehensive information on ivermectin, including its safety and efficacy, as well as its adverse effects in the treatment of COVID-19.

Use of Ivermectin and Chlorine Dioxide for COVID-19 Treatment and Prophylaxis in Peru: A Narrative Review

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, created a rapidly unfolding health crisis, especially in the initial phases of the pandemic. In the early stages of the pandemic, various strategies were proposed for COVID-19 prophylaxis and treatment with very little scientific evidence available. Among these proposed treatments were ivermectin and chlorine dioxide, which were both used widely in Peru for both disease prevention and treatment without considering their problematic side effects. For instance, ivermectin was part of an approved therapeutic scheme based on in vitro data, although its efficacy in humans was not demonstrated. In addition, chlorine dioxide was never shown to be effective but causes threatening side effects. In this article, we discuss current information regarding chlorine dioxide and ivermectin in the context of the COVID-19 pandemic, with a focus on experiences in Peru.

Progress, pitfalls, and path forward of drug repurposing for COVID-19 treatment

On 30 January 2020, the World Health Organization (WHO) declared the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic a public health emergency of international concern. The viral outbreak led in turn to an exponential growth of coronavirus disease 2019 (COVID-19) cases, that is, a multiorgan disease that has led to more than 6.3 million deaths worldwide, as of June 2022. There are currently few effective drugs approved for treatment of SARS-CoV-2/COVID-19 patients. Many of the compounds tested so far have been selected through a drug repurposing approach, that is, by identifying novel indications for drugs already approved for other conditions. We here present an up-to-date review of the main Food and Drug Administration (FDA)-approved drugs repurposed against SARS-CoV-2 infection, discussing their mechanism of action and their most important preclinical and clinical results. Reviewed compounds were chosen to privilege those that have been approved for use in SARS-CoV-2 patients or that have completed phase III clinical trials. Moreover, we also summarize the evidence on some novel and promising repurposed drugs in the pipeline. Finally, we discuss the current stage and possible steps toward the development of broadly effective drug combinations to suppress the onset or progression of COVID-19.

Immunomodulatory Effects of Chicken Broth and Histidine Dipeptides on the Cyclophosphamide-Induced Immunosuppression Mouse Model

The carnosine and anserine, which represent histidine dipeptides (HD), are abundant in chicken broth (CB). HD are endogenous dipeptide that has excellent antioxidant and immunomodulatory effects. The immunomodulatory effect of CB hydrolysate (CBH) and HD in cyclophosphamide (CTX)-induced immunosuppressed mice was examined in this study. CBH and HD were given to mice via oral gavage for 15 days, accompanied by intraperitoneal CTX administration to induce immunosuppression. CBH and HD treatment were observed to reduce immune organ atrophy (p < 0.05) and stimulate the proliferation of splenic lymphocytes (p < 0.05) while improving white blood cell, immunoglobulin M (IgM), IgG, and IgA levels (p < 0.05). Moreover, CBH and HD strongly stimulated interleukin-2 (IL-2) and interferon-gamma (IFN-γ) production by up-regulating IL-2 and IFN-γ mRNA expression (p < 0.05) while inhibiting interleukin-10 (IL-10) overproduction and IL-10 mRNA expression (p < 0.05). In addition, CBH and HD prevented the inhibition of the nitric oxide (NP)/cyclic guanosine monophosphate-cyclic adenosine monophosphate (cGMP-cAMP)/protein kinase A (PKA) signaling pathway (p < 0.05). These results indicate that CBH and HD have the potential to prevent immunosuppression induced by CTX. Our data demonstrate that CBH can effectively improve the immune capacity of immunosuppressed mice similar to the same amount of purified HD, which indicates that CBH plays its role through its own HD.

An Update on the Biologic Effects of Fenbendazole

Fenbendazole remains the drug of choice to treat pinworm infection in laboratory rodents. When fenbendazole was last reviewed (15 y ago), the literature supported the drug's lack of toxic effects at therapeutic levels, yet various demonstrated physiologic effects have the potential to alter research outcomes. Although more recent reports continue to reflect an overall discordancy of results, several studies support the premise that fenbendazole affects the bone marrow and the immune system. No effects on reproduction were reported in an extensive study that assessed common treatment protocols in mice, and food intake was unchanged in rats. Behavioral studies are sparse, with only a single report of a subtle change in a rotarod performance in mice. Notably, unexpected results in tumor models during facility treatment with fenbendazole have prompted preclinical and clinical studies of the potential roles of benzimidazoles in cancer.

Non-effectiveness of Ivermectin on Inpatients and Outpatients With COVID-19; Results of Two Randomized, Double-Blinded, Placebo-Controlled Clinical Trials

Background

Ivermectin which was widely considered as a potential treatment for COVID-19, showed uncertain clinical benefit in many clinical trials. Performing large-scale clinical trials to evaluate the effectiveness of this drug in the midst of the pandemic, while difficult, has been urgently needed.

Methods

We performed two large multicenter randomized, double-blind, placebo-controlled clinical trials evaluating the effectiveness of ivermectin in treating inpatients and outpatients with COVID-19 infection. The intervention group received ivermectin, 0.4mg/kg of body weight per day for 3 days. In the control group, placebo tablets were used for 3 days.

Results

Data for 609 inpatients and 549 outpatients were analyzed. In hospitalized patients, complete recovery was significantly higher in the ivermectin group (37%) compared to placebo group (28%; RR, 1.32 [95% CI, 1.04–1.66]; p-value = 0.02). On the other hand, the length of hospital stay was significantly longer in the ivermectin group with a mean of 7.98 ± 4.4 days compared to the placebo receiving group with a mean of 7.16 ± 3.2 days (RR, 0.80 [95% CI, 0.15–1.45]; p-value = 0.02). In outpatients, the mean duration of fever was significantly shorter (2.02 ± 0.11 days) in the ivermectin group versus (2.41 ± 0.13 days) placebo group with p value = 0.020. On the day seventh of treatment, fever (p-value = 0.040), cough (p-value = 0.019), and weakness (p-value = 0.002) were significantly higher in the placebo group compared to the ivermectin group. Among all outpatients, 7% in ivermectin group and 5% in placebo group needed to be hospitalized (RR, 1.36 [95% CI, 0.65–2.84]; p-value = 0.41). Also, the result of RT-PCR on day five after treatment was negative for 26% of patients in the ivermectin group versus 32% in the placebo group (RR, 0.81 [95% CI, 0.60–1.09]; p-value = 0.16).

Conclusion

Our data showed, ivermectin, compared with placebo, did not have a significant potential effect on clinical improvement, reduced admission in ICU, need for invasive ventilation, and death in hospitalized patients; likewise, no evidence was found to support the prescription of ivermectin on recovery, reduced hospitalization and increased negative RT-PCR assay for SARS-CoV-2 5 days after treatment in outpatients. Our findings do not support the use of ivermectin to treat mild to severe forms of COVID-19.

Clinical Trial Registration

www.irct.ir IRCT20111224008507N5 and IRCT20111224008507N4.

Safety and Efficacy of a MEURI Program for the Use of High Dose Ivermectin in COVID-19 Patients

Background

In the absence of antiviral alternatives, interventions under research for COVID-19 might be offered following guidelines from WHO for monitored emergency use of unregistered and experimental interventions (MEURI). Ivermectin is among several drugs explored for its role against SARS-CoV-2, with a well-known safety profile but conflicting data regarding clinical utility for COVID-19. The aim of this report is to inform on the results of a MEURI Program of high-dose ivermectin in COVID-19 carried out by the Ministry of Health of the Province of La Pampa, Argentina.

Methods

COVID-19 subjects, within 5 days of symptoms onset were invited to participate in the program, which consisted in the administration of ivermectin 0.6 mg/kg/day for 5 days plus standard of care. Active pharmacosurveillance was performed for 21 days, and hepatic laboratory assessments were performed in a subset of patients. Frequency of Intensive Care Unit (ICU) admission and COVID-19-related mortality of subjects in the ivermectin intention to treat group were compared with that observed in inhabitants of the same province during the same period not participating in the program.

Results

From 21,232 subjects with COVID-19, 3,266 were offered and agreed to participate in the ivermectin program and 17,966 did not and were considered as controls. A total of 567 participants reported 819 adverse events (AEs); 3.13% discontinued ivermectin due to adverse events. ICU admission was significantly lower in the ivermectin group compared to controls among participants ≥40 year-old (1.2 vs. 2.0%, odds ratio 0.608; p = 0.024). Similarly, mortality was lower in the ivermectin group in the full group analysis (1.5 vs. 2.1%, odds ratio 0.720; p = 0.029), as well as in subjects ≥ 40 year- old (2.7 vs. 4.1%, odds ratio 0.655; p = 0.005).

Conclusions

This report highlights the safety and possible efficacy of high dose ivermectin as a potentially useful intervention deserving public health-based consideration for COVID-19 patients.

Therapeutic efficacy of triclabendazole in comparison to combination of triclabendazole and levamisole in sheep naturally infected with Fasciola sp

Fascioliasis is an important parasitic disease which affects productivity of ruminants, and imposes significant economic losses. Benzimidazoles are effective in the treatment of fascioliasis; however, there are several reports on benzimidazoles resistant flukes. Combinational therapy is an approach to delay the emergence of resistant flukes. The present study aimed to compare the efficacy of triclabendazole (TBZ) and combination of triclabendazole and levamisole (TBZ + LVM) in the treatment of sheep naturally infected with Fasciola sp. For this purpose, 40 ewes infected with Fasciola sp. in three groups received TBZ, and TBZ + LVM, or remained untreated as CON. Fecal egg count (FEC), fecal egg count reduction (FECR), liver enzymes activity, albumin, globulin, and total protein levels were measured on day 0, 7, 14, and 28 post treatments. Obtained results showed that treatment with TBZ and TBZ + LVM resulted in significant reduction in FEC (P < 0.05), and FECR reached to values of higher than 90% on 28 day post treatment. The FEC for TBZ + LMV on day 7 and 14 were 12.25 ± 3.82 and 3.08 ± 1.03, respectively which was significantly lower in comparison to TBZ and CON (P < 0.05). Efficacy of TBZ + LMV was higher than TBZ on day 7 and 14 post treatment; however, no significant difference was observed on 28 day. The liver enzyme activities on days 7 and 14 were lower in the TBZ + LVM sheep in comparison to the TBZ and CON. Treatment with TBZ or TBZ + LVM resulted in an increase in albumin and a decrease in globulin. Over all, the present study clarified the importance of combinational therapy, and demonstrated that combination of TBZ + LVM resulted in higher efficacy and earlier improvement of liver conditions in sheep naturally infected with Fasciola sp.

Ivermectin (IVM) Possible Side Activities and Implications in Antimicrobial Resistance and Animal Welfare: The Authors' Perspective

Ivermectin has a wide number of many diverse functions. Certainly, it is irreplaceable for the treatment of parasitic pathologies in both human and veterinary medicine, and the latter represents the major field of its application. It has been called the "drug for the world's poor" because of its role as a saviour for those living on the margins of society, in underdeveloped areas afflicted by devastating and debilitating diseases, such as Onchocerciasis and Lymphatic filariasis. It showed huge, unexpected potential as an antibacterial (Chlamydia trachomatis and mycobacteria), and it has antiviral and anti-inflammatory properties. The research line described here is placed right in the middle of the investigation on the impact of this drug as an antimicrobial and an immunomodulator. Being a drug widely employed for mass administration, it is mandatory to broaden the knowledge of its possible interaction with bacterial growth and its generation of antimicrobial resistance. Equally, it is important to understand the impact of these drugs on the immune systems of animal species, e.g., horses and dogs, in which this drug is often used. More importantly, could immunomodulation and antibacterial activity promote both bacterial growth and the occurrence of resistance mechanisms?

The antimicrobial and immunomodulatory effects of Ionophores for the treatment of human infection

Ionophores are a diverse class of synthetic and naturally occurring ion transporter compounds which demonstrate both direct and in-direct antimicrobial properties against a broad panel of bacterial, fungal, viral and parasitic pathogens. In addition, ionophores can regulate the host-immune response during communicable and non-communicable disease states. Although the clinical use of ionophores such as Amphotericin B, Bedaquiline and Ivermectin highlight the utility of ionophores in modern medicine, for many other ionophore compounds issues surrounding toxicity, bioavailability or lack of in vivo efficacy studies have hindered clinical development. The antimicrobial and immunomodulating properties of a range of compounds with characteristics of ionophores remain largely unexplored. As such, ionophores remain a latent therapeutic avenue to address both the global burden of antimicrobial resistance, and the unmet clinical need for new antimicrobial therapies. This review will provide an overview of the broad-spectrum antimicrobial and immunomodulatory properties of ionophores, and their potential uses in clinical medicine for combatting infection.

Regression of bovine cutaneous papillomas via ivermectin-induced immunostimulant and oxidative stress

OBJECTIVE

Ivermectin (IVM) could be used effectively to treat bovine cutaneous papillomatosis, a widespread viral skin disease that causes major economic losses in cattle. This study aimed to evaluate the regression of bovine cutaneous papillomas induced by IVM by estimating oxidative stress markers, besides clinicopathological and hematological findings.

MATERIALS AND METHODS

Twenty naturally infected animals with cutaneous papillomatosis were chosen randomly and diagnosed clinically and histopathologically. All the infected animals were divided into groups: Group I (n = 10), which received no treatment and was considered the control group. In Group II (n = 10), the animals were subcutaneously injected at 0.2 mg/kg of IVM 2 weeks apart during the 90-day experimental period. Papilloma regression was tracked clinically, papilloma biopsies were taken for histopathological analysis, and blood samples were taken for hematological and oxidative parameter testing.

RESULTS

From the 15th to 45th day after receiving IVM, papillomas began to fade. Necrotic areas, ulcerations, and lymphocytic infiltration were found in the histopathological studies, besides a decrease in papilloma epidermal proliferation. total erythrocytes count, packed cell volume, total leucocytes count, and lymphocytes values were increased significantly, and a large decrease in glutathione peroxidase and glutathione reduced was identified as signs of IVM-induced oxidative stress.

CONCLUSION

IVM has oxidative and immunostimulatory properties, and it can be used against cutaneous papillomatosis.

Attenuation of clinical and immunological outcomes during SARS-CoV-2 infection by ivermectin

The devastating pandemic due to SARS-CoV-2 and the emergence of antigenic variants that jeopardize the efficacy of current vaccines create an urgent need for a comprehensive understanding of the pathophysiology of COVID-19, including the contribution of inflammation to disease. It also warrants for the search of immunomodulatory drugs that could improve disease outcome. Here, we show that standard doses of ivermectin (IVM), an anti-parasitic drug with potential immunomodulatory activities through the cholinergic anti-inflammatory pathway, prevent clinical deterioration, reduce olfactory deficit, and limit the inflammation of the upper and lower respiratory tracts in SARS-CoV-2-infected hamsters. Whereas it has no effect on viral load in the airways of infected animals, transcriptomic analyses of infected lungs reveal that IVM dampens type I interferon responses and modulates several other inflammatory pathways. In particular, IVM dramatically reduces the Il-6/Il-10 ratio in lung tissue and promotes macrophage M2 polarization, which might account for the more favorable clinical presentation of IVM-treated animals. Altogether, this study supports the use of immunomodulatory drugs such as IVM, to improve the clinical condition of SARS-CoV-2-infected patients.

Ivermectin reduces in vivo coronavirus infection in a mouse experimental model

The objective of this study was to test the effectiveness of ivermectin for the treatment of mouse hepatitis virus (MHV), a type 2 family RNA coronavirus similar to SARS-CoV-2. Female BALB/cJ mice were infected with 6,000 PFU of MHV-A59 (group infected, n = 20) or infected and then immediately treated with a single dose of 500 µg/kg ivermectin (group infected + IVM, n = 20) or were not infected and treated with PBS (control group, n = 16). Five days after infection/treatment, the mice were euthanized and the tissues were sampled to assess their general health status and infection levels. Overall, the results demonstrated that viral infection induced typical MHV-caused disease, with the livers showing severe hepatocellular necrosis surrounded by a severe lymphoplasmacytic inflammatory infiltration associated with a high hepatic viral load (52,158 AU), while mice treated with ivermectin showed a better health status with a lower viral load (23,192 AU; p < 0.05), with only a few having histopathological liver damage (p < 0.05). No significant differences were found between the group infected + IVM and control group mice (P = NS). Furthermore, serum transaminase levels (aspartate aminotransferase and alanine aminotransferase) were significantly lower in the treated mice than in the infected animals. In conclusion, ivermectin diminished the MHV viral load and disease in the mice, being a useful model for further understanding this therapy against coronavirus diseases.

Cellular and Molecular Immunology Approaches for the Development of Immunotherapies against the New Coronavirus (SARS-CoV-2): Challenges to Near-Future Breakthroughs

The severe acute respiratory syndrome caused by the new coronavirus (SARS-CoV-2), termed COVID-19, has been highlighted as the most important infectious disease of our time, without a vaccine and treatment available until this moment, with a big impact on health systems worldwide, and with high mortality rates associated with respiratory viral disease. The medical and scientific communities have also been confronted by an urgent need to better understand the mechanism of host-virus interaction aimed at developing therapies and vaccines. Since this viral disease can trigger a strong innate immune response, causing severe damage to the pulmonary tract, immunotherapies have also been explored as a means to verify the immunomodulatory effect and improve clinical outcomes, whilst the comprehensive COVID-19 immunology still remains under investigation. In this review, both cellular and molecular immunopathology as well as hemostatic disorders induced by SARS-CoV-2 are summarized. The immunotherapeutic approaches based on the most recent clinical and nonclinical studies, emphasizing their effects for the treatment of COVID-19, are also addressed. The information presented elucidates helpful insights aiming at filling the knowledge gaps around promising immunotherapies that attempt to control the dysfunction of host factors during the course of this infectious viral disease.

Drug repurposing and cytokine management in response to COVID-19: A review

Coronavirus disease 2019 (COVID-19), the infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an aggressive disease that attacks the respiratory tract and has a higher fatality rate than seasonal influenza. The COVID-19 pandemic is a global health crisis, and no specific therapy or drug has been formally recommended for use against SARS-CoV-2 infection. In this context, it is a rational strategy to investigate the repurposing of existing drugs to use in the treatment of COVID-19 patients. In the meantime, the medical community is trialing several therapies that target various antiviral and immunomodulating mechanisms to use against the infection. There is no doubt that antiviral and supportive treatments are important in the treatment of COVID-19 patients, but anti-inflammatory therapy also plays a pivotal role in the management COVID-19 patients due to its ability to prevent further injury and organ damage or failure. In this review, we identified drugs that could modulate cytokines levels and play a part in the management of COVID-19. Several drugs that possess an anti-inflammatory profile in others illnesses have been studied in respect of their potential utility in the treatment of the hyperinflammation induced by SAR-COV-2 infection. We highlight a number of antivirals, anti-rheumatic, anti-inflammatory, antineoplastic and antiparasitic drugs that have been found to mitigate cytokine production and consequently attenuate the "cytokine storm" induced by SARS-CoV-2. Reduced hyperinflammation can attenuate multiple organ failure, and even reduce the mortality associated with severe COVID-19. In this context, despite their current unproven clinical efficacy in relation to the current pandemic, the repurposing of drugs with anti-inflammatory activity to use in the treatment of COVID-19 has become a topic of great interest.

A Review on Current Repurposing Drugs for the Treatment of COVID-19: Reality and Challenges

The coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic with a high growth rate of confirmed cases. Therefore, therapeutic options are desperately urgent to fight with this damning virus. As it may take years to develop a specific therapy of COVID-19, it is urgent to emphasize the repurposing of drugs used for other conditions. This study reviewed the most common drugs for COVID-19 based on available online literature representing the latest in vitro clinical trial database, rational of use, adverse effects, potential toxicities, and US National Institute of Health (NIH) recommendation to use for COVID-19. Based on the preliminary data from clinical trials and considering the NIH and FDA recommendation, remdesivir and convalescent blood products are the most promising potential for COVID-19 treatment. The use of chloroquine, hydroxychloroquine, favipiravir, ivermectin, and colchicine might also be effective. However, furthermore, in vivo investigations are needed in detail individually and in combination for possible benefits in humans. Besides, tocilizumab might be deemed as adjunctive therapy for patients with cytokine release syndrome. However, lopinavir-ritonavir, anakinra, and sarilumab had not proven their clinical efficacy. Eventually, sarilumab has been withdrawn from sponsored clinical trials based on the preliminary data. Baricitinib and ruxolitinib have the additive immunosuppressive effect. Consequently, all of these drugs are being evaluated with further studies. In addition, drug-drug interaction and safety concerns must be taken into account before the administration of the recommended drugs.

Nonexperimental Xenobiotics: Unintended Consequences of Intentionally Administered Substances in Terrestrial Animal Models

Review of the use of nonexperimental xenobiotics in terrestrial animal models and the potential unintended consequences of these compounds, including drug-related side effects and adverse reactions.

Old and re-purposed drugs for the treatment of COVID-19

Introduction

The coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has developed since December 2019. It has caused a global pandemic with more than three hundred thousand case fatalities. However, apart from supportive care by respirators, no standard medical therapy is validated.

Areas covered

This paper presents old drugs with potential in vitro efficacy against SARS-CoV-2. The in vitro database, adverse effects, and potential toxicities of these drugs are reviewed regarding their feasibility of clinical prescription for the treatment of patients with COVID-19. To obtain convincing recommendations, we referred to opinions from the US National Institute of Health regarding drugs repurposed for COVID-19 therapy.

Expert opinion

Although strong evidence of well-designed randomized controlled studies regarding COVID-19 therapy is presently lacking, remdesivir, teicoplanin, hydroxychloroquine (not in combination with azithromycin), and ivermectin might be effective antiviral drugs and are deemed promising candidates for controlling SARS-CoV-2. In addition, tocilizumab might be considered as the supplementary treatment for COVID-19 patients with cytokine release syndrome. In future, clinical trials regarding a combination of potentially effective drugs against SARS-CoV-2 need to be conducted to establish the optimal regimen for the treatment of patients with moderate-to-severe COVID-19.

Pharmacokinetics of levamisole in the red-eared slider turtles (Trachemys scripta elegans)

The pharmacokinetics and bioavailability of levamisole were determined in red-eared slider turtles after single intravenous (IV), intramuscular (IM), and subcutaneous (SC) administration. Nine turtles received levamisole (10 mg/kg) by each route in a three-way crossover design with a washout period of 30 days. Blood samples were collected at time 0 (pretreatment), and at 0.25, 0.5, 1, 1.5, 3, 6, 9, 12, 18, 24, 36, and 48 hr after drug administration. Plasma levamisole concentrations were determined by a high-performance liquid chromatography assay. Data were analyzed by noncompartmental methods. The mean elimination half-life was 5.00, 7.88, and 9.43 hr for IV, IM, and SC routes, respectively. The total clearance and volume of distribution at steady state for the IV route were 0.14 L hr^-1  kg^-1 and 0.81 L/kg, respectively. For the IM and SC routes, the peak plasma concentration was 9.63 and 10.51 μg/ml, respectively, with 0.5 hr of T_max . The bioavailability was 93.03 and 115.25% for the IM and SC routes, respectively. The IM and SC route of levamisole, which showed the high bioavailability and long t_1/2ʎz , can be recommended as an effective way for treating nematodes in turtles.

Repositioning Flubendazole for Spinal Cord Injury

We previously reported the serendipitous observation that fenbendazole, a benzimidazole anthelmintic, improved functional and pathological outcomes following thoracic spinal cord contusion injury in mice when administered pre-injury. Fenbendazole is widely used in veterinary medicine. However, it is not approved for human use and it was uncertain if only post-injury administration would offer similar benefits. In the present study we evaluated post-injury administration of a closely related, human anthelmintic drug, flubendazole, using a rat spinal cord contusion injury model. Flubendazole, administered i.p. 5 or 10 mg/kg day, beginning 3 h post-injury and daily thereafter for 2 or 4 weeks, resulted in improved locomotor function after contusion spinal cord injury (SCI) compared with vehicle-treated controls. Histological analysis of spinal cord sections showed that such treatment with flubendazole also reduced lesion volume and improved total tissue sparing, white matter sparing, and gray matter sparing. Flubendazole inhibited the activation of glial fibrillary acidic protein (GFAP); suppressed cyclin B1 expression and Bruton tyrosine kinase activation, markers of B cell activation/proliferation and inflammation; and reduced B cell autoimmune response. Together, these results suggest the use of the benzimidazole anthelmintic flubendazole as a potential therapeutic for SCI.

Cellular immune responses in peripheral blood lymphocytes of Giardia infected squirrel monkey (Saimiri boliviensis boliviensis) treated with Fenbendazole

Cellular immune responses were tested to determine the effect of fenbendazole on the function of lymphocytes from Bolivian squirrel monkeys (Samiri boliviensis boliviensis). Giardia-infected squirrel monkeys were treated with commercially available fenbendazole (FBZ)-medicated monkey chow. Immune responses were compared between historical controls (Giardia naïve, untreated with FBZ (control animals)) and Giardia-infected, FBZ-treated squirrel monkeys (study animals). Peripheral blood lymphocytes from study monkeys had significantly lower stimulation indices compared to control animals when cultured in vitro with concanavalin A (Con A) (p<0.0001), phytohaemagglutinin (PHA) (p<0.0001) and lipopolysaccharide (LPS) (p<0.0001). PBMCs were also analyzed for IFN-γ producing cells in response to stimulation with Con A, PHA, PWM, and LPS by the cytokine ELISPOT assay. Significantly higher responses to Con A- (p<0.0001), and PHA- (p<0.001) stimulated cultures from Giardia-infected and fenbendazole treated compared to controls. Flow cytometric analysis for expression of cell surface markers revealed a significant increase in B- and NKT-lymphocytes and significant decrease in CD14+CD16+ monocytes after FBZ treatment. Also, circulating plasma cytokines IFN-γ, TNF-α, IL-12p40, IL-1β, IL-10, IL-13, IL-1ra, IL-6 and IL-4 were significantly decreased after FBZ treatment. Comparison of hematologic parameters between controls and FBZ-treated squirrel monkeys revealed significantly lower numbers of total leukocytes, neutrophils, monocytes, and eosinophils compared to controls. However, erythrocyte indices (red cell count, hemoglobin and hematocrit were significantly higher in FBZ-treated monkeys. Our findings suggest that fenbendazole treatment may alter sensitive immune and molecular measures of inflammation. Postponing the experimental use of squirrel monkeys until at least 6 weeks after FBZ treatment should be considered.

Mebendazole, an antiparasitic drug, inhibits drug transporters expression in preclinical model of gastric peritoneal carcinomatosis

The present study aimed to investigate whether MBZ down-regulates drug transporter expression (ABCB1, ABCC1, SLC47A1). mRNA expression level of ABCB1, ABCC1 and SLC47A1 was evaluated by qPCR and protein expression levels MDR-1 was performed by western blotting in malignant ascites cells (AGP-01) treated with MBZ for 24h. The mRNA expression level of ABCB1 and ABCC1 significantly decreased at a 1.0μM of MBZ compared to negative control, while SLC47A1 extremely decreased at all tested concentrations of MBZ. Protein expression levels MDR-1 significantly decreased at a 1.0μM of MBZ compared to negative control. Therefore, our results showed MBZ may play an important role in inhibiting MDR gene expression in malignant ascites cells.

Therapeutics for Equine Protozoal Myeloencephalitis

Equine protozoal myeloencephalitis is an infectious disease of the central nervous system caused by Sarcocystis neurona or Neospora hughesi. Affected horses routinely present with progressive and asymmetrical neurologic deficits. The diagnosis relies on the presence of neurologic signs, ruling out other neurologic disorders, and the detection of intrathecally derived antibodies to either S neurona and/or N hughesi. Recommended treatment is use of an FDA-approved anticoccidial drug formulation. Medical and supportive treatment is provided based on the severity of neurologic deficits and complications. This article focuses on recent data related to diagnosis, pharmacologic treatment, and prevention.

Protective effects of levamisole, acetylsalicylic acid, and α-tocopherol against dioxin toxicity measured as the expression of AhR and COX-2 in a chicken embryo model

Polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxins) are classed as persistent organic pollutants and have adverse effects on multiple functions within the body. Dioxins are known carcinogens, immunotoxins, and teratogens. Dioxins are transformed in vivo, and interactions between the products and the aryl hydrocarbon receptor (AhR) lead to the formation of proinflammatory and toxic metabolites. The aim of this study was to determine whether α-tocopherol (vitamin E), acetylsalicylic acid (ASA), and levamisole can decrease the amount of damage caused by dioxins. Fertile Hubbard Flex commercial line chicken eggs were injected with solutions containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or containing TCDD and the test compounds. The chicken embryos and organs were analyzed after 7 and 13 days. The levels at which AhR and cyclooxygenase-2 (COX-2) proteins (which are induced during inflammation) were expressed were evaluated by performing immunohistochemical analyses on embryos treated with TCDD alone or with TCDD and the test compounds. TCDD caused developmental disorders and increased AhR and COX-2 expression in the chicken embryo tissues. Vitamin E, levamisole, ASA, and ASA plus vitamin E inhibited AhR and COX-2 expression in embryos after 7 days and decreased AhR and COX-2 expression in embryos after 13 days. ASA, levamisole, and ASA plus vitamin E weakened the immune response and prevented multiple organ changes. Vitamin E was not fully protective against developmental changes in the embryos.

Albendazole residues in goat's milk: Interferences in microbial inhibitor tests used to detect antibiotics in milk

Albendazole (ABZ) residues in goat's milk and their effect on the response of microbial inhibitor tests used for screening antibiotics were evaluated. A total of 18 Murciano-Granadina goats were treated with ABZ and individually milked once a day over a 7-day period. ABZ quantification was performed by high performance liquid chromatography. The ABZ parent drug was not detected. The maximum concentration of its metabolites (ABZ sulfoxide, ABZ sulfone, and ABZ 2-aminosulfone) was reached on the 1^st day post treatment (260.0 ± 70.1 μg/kg, 112.8 ± 28.7 μg/kg, 152.0 ± 23.6 μg/kg, respectively), decreasing to lower than the maximum residue limit (MRL, 100 μg/kg) on the 3^rd day post treatment. Milk samples were also analyzed by microbial tests [Brilliant Black Reduction Test (BRT) MRL, Delvotest SP-NT MCS and Eclipse 100], and only one positive result was found for Delvotest SP-NT MCS and Eclipse 100. However, a high occurrence of positive outcomes was obtained for BRT MRL during 6 days post treatment, whereas ABZ residues were not detected from the 4^th day post administration, suggesting that factors other than the antiparasitic agent might affect the microbial test response.

Making sense of the cause of Crohn's - a new look at an old disease

The cause of Crohn’s disease (CD) has posed a conundrum for at least a century. A large body of work coupled with recent technological advances in genome research have at last started to provide some of the answers. Initially this review seeks to explain and to differentiate between bowel inflammation in the primary immunodeficiencies that generally lead to very early onset diffuse bowel inflammation in humans and in animal models, and the real syndrome of CD. In the latter, a trigger, almost certainly enteric infection by one of a multitude of organisms, allows the faeces access to the tissues, at which stage the response of individuals predisposed to CD is abnormal. Direct investigation of patients’ inflammatory response together with genome-wide association studies (GWAS) and DNA sequencing indicate that in CD the failure of acute inflammation and the clearance of bacteria from the tissues, and from within cells, is defective. The retained faecal products result in the characteristic chronic granulomatous inflammation and adaptive immune response. In this review I will examine the contemporary evidence that has led to this understanding, and look for explanations for the recent dramatic increase in the incidence of this disease.

Making sense of the cause of Crohn's - a new look at an old disease

The cause of Crohn's disease (CD) has posed a conundrum for at least a century. A large body of work coupled with recent technological advances in genome research have at last started to provide some of the answers. Initially this review seeks to explain and to differentiate between bowel inflammation in the primary immunodeficiencies that generally lead to very early onset diffuse bowel inflammation in humans and in animal models, and the real syndrome of CD. In the latter, a trigger, almost certainly enteric infection by one of a multitude of organisms, allows the faeces access to the tissues, at which stage the response of individuals predisposed to CD is abnormal. Direct investigation of patients' inflammatory response together with genome-wide association studies (GWAS) and DNA sequencing indicate that in CD the failure of acute inflammation and the clearance of bacteria from the tissues, and from within cells, is defective. The retained faecal products result in the characteristic chronic granulomatous inflammation and adaptive immune response. In this review I will examine the contemporary evidence that has led to this understanding, and look for explanations for the recent dramatic increase in the incidence of this disease.

Schistosoma japonicum HSP60-derived peptide SJMHE1 suppresses delayed-type hypersensitivity in a murine model

Background

Parasite-derived molecules with immunomodulatory properties, which have been optimised during host-parasite co-evolution, exhibit potential applications as novel immunotherapeutics. We have previously demonstrated that Schistosoma japonicum HSP60-derived peptide SJMHE1 induces CD4⁺CD25⁺ regulatory T-cells (Tregs) and that adoptively transferred SJMHE1-induced CD4⁺CD25⁺ Tregs inhibit delayed-type hypersensitivity (DTH) in mice. However, multiple concerns regarding this method render this treatment unsuitable. To gain further insights into the potential effects of SJMHE1, we used ovalbumin (OVA)-induced DTH and evaluated the effect of SJMHE1 on DTH mice.

Methods

BALB/c mice were sensitised with OVA alone or combined with SJMHE1 and then challenged with OVA to induce DTH. We first analysed the potential effects of SJMHE1 by measuring DTH responses, T-cell responses, cytokine secretion, and Treg proportions. We then evaluated the expression levels of IL-10 and TGF-β1 in CD4⁺CD25⁺ T-cells during DTH and Treg generation to identify the mechanism by which SJMHE1 suppresses DTH.

Results

SJMHE1 modulated the effector response against OVA-induced DTH and stimulated the production of the anti-inflammatory cytokines IL-10 and TGF-β1 in immunised mice through a mechanism involving CD4⁺CD25⁺ Tregs. SJMHE1-induced CD4⁺CD25⁺ Tregs expressed high levels of CTLA-4, IL-10, and TGF-β1, which substantially contributed to the suppressive activity during DTH. The administration of SJMHE1 to DTH in mice led to the expansion of CD4⁺CD25⁺ Tregs from CD4⁺CD25⁻ T-cells in the periphery, which inhibited DTH responses.

Conclusions

Our study proves that the parasite-driven peptide suppresses DTH in mice, which may confer a new option for inflammation treatment.

Influence of levamisole and Freund's adjuvant on mouse immunisation with antigens of adults of the liver fluke Fasciola hepatica Linnaeus, 1758

We have studied the influence of both levamisole (AL) and Freund's adjuvant (AF) on the immunisation of mice with the secretory antigens of adults of the liver fluke Fasciola hepatica Linnaeus, 1758. Total IgG antibodies were detected in all groups where the F. hepatica antigen was administered, been levels of IgG1 increased respect to IgG2a antibodies. During immunisation, IL-4 and IFN-γ were only detected in AL and AF groups, but after infection, IL-4 boosted in all groups. IFN-γ increased two fold in AF and AL groups compared to the saline solution (AS) group. Worm recovering was of 32-35% in groups administered without antigen whereas in AS, AL and AF groups recovering was of 25%, 12% and 8%, respectively. Macroscopical lesions in the liver were scarce in AL and AF groups. Our data suggest that immunisation of mice with antigens of F. hepatica enhances the immune response avoiding both liver damage and worm establishment after challenge infection. The murine model of fasciolosis has appeared to be useful to elucidate the mechanism by which the parasite modulates immune responses toward a Th2 type but also the development of Th1 type-inducing vaccines.

The anthelmintic drug mebendazole inhibits growth, migration and invasion in gastric cancer cell model

The present study aimed to investigate the effects of MBZ on a human malignant ascites cell line derived from a primary gastric cancer tumor. Our data reveal that MBZ showed high cytotoxicity in vitro, displaying an IC50 of 0.39 μM and 1.25 μM in ACP-02 and ACP-03, respectively. The association between MBZ and 5-FU increased slightly the cytotoxicity when compared to MBZ and 5-FU alone. Furthermore, MBZ disrupted the microtubule structure of AGP-01 cells and inhibited significantly the invasion and migration of these cells. Activity of active MMP-2 significantly decreased at all tested concentration of MBZ compared to negative control. These results support the indication of MBZ in combination with chemotherapeutic agents as a possible adjuvant therapy for the management/treatment of patients with advanced gastric cancer since MBZ is a drug of low cost with acceptable safety profile and reduced toxicity to normal cells. However, clinical trials must be performed in o to evaluate its efficacy in gastric cancer patients.

Nonimmunologic targets of immunosuppressive agents in podocytes

Proteinuria is a characteristic finding in glomerular diseases and is closely associated with renal outcomes. In addition, therapeutic interventions that reduce proteinuria improve renal prognosis. Accumulating evidence has demonstrated that podocytes act as key modulators of glomerular injury and proteinuria. The podocyte, or glomerular visceral epithelial cell, is a highly specialized and differentiated cell that forms interdigitated foot processes with neighboring podocytes, which are bridged together by an extracellular structure known as the "slit diaphragm" (SD). The SD acts as a size- and charge-selective barrier to plasma protein. Derangement of SD structure or loss of SD-associated protein results in podocyte injury and proteinuria. During the past decades, several immune-modulating agents have been used for the treatment of glomerular diseases and for the reduction of proteinuria. Interestingly, recent studies have demonstrated that immunosuppressive agents can have a direct effect on the SD-associated proteins and stabilize actin cytoskeleton in podocyte and have therefore introduced the concept of nonimmunologic mechanism of renoprotection by immunomodulators. This review focuses on the evidence that immuno-modulating agents directly target podocytes.

Antineutrophil cytoplasmic antibody mediated glomerulonephritis associated with levamisole-adulterated cocaine

Levamisole-adulterated cocaine has increased in prevalence over the last decade and is known to be associated with antineutrophil cytoplasmic antibodies (ANCA). Dermatologic manifestations of levamisole exposure, including cutaneous vasculitis, are widely appreciated; less is known about its effects on the kidney. We report two cases of patients with a history of cocaine abuse and levamisole-induced cutaneous vasculitis, who developed acute kidney injury in the setting of elevated ANCA titers. Renal biopsies of both revealed pauci-immune complex glomerulonephritis with diffuse crescentic disease. These cases demonstrate a rare but serious complication of long-term cocaine use.

Immunomodulatory effect of diethylcarbamazine in mice infected with Nocardia brasiliensis

We tested whether diethylcarbamazine (DEC) or ivermectin (IVM), both antiparasitic drugs with reported immunomodulatory properties, were able to affect the immune system to potentiate host defense mechanisms and protect against actinomycetoma in a mouse model. Male BALB/c mice of 10-12 weeks of age were injected with either Nocardia brasiliensis or saline solution. Recorded were the effects of a treatment by DEC (6 mg/kg per os daily for one week) or IVM (200 μg/kg subcutaneously on days 1 and 3) on (i) the development of mycetoma lesion, (ii) the expression of reactive oxygen intermediates (ROI) by phagocytes, (iii) the proliferation index of lymphocytes and (iv) antibody production of IgG and IgM. After an initial lesion in all mice, DEC inhibited a full development and progression of actinomycetoma resulting in a reduced lesion size (p < 0.001). IVM had no inhibitory effect on the development of mycetoma. Furthermore, DEC treatment was associated with a significant enhancement of ROI expression (p < 0.05) by polymorphonuclear neutrophils at day 3 after infection. Lymphocyte proliferation in response to N. brasiliensis antigens and concanavalin A in DEC-treated group was higher than in non-treated group at day 21 and 28 postinfection (p < 0.01). Significant changes in antibody response were not observed. By all parameters tested, DEC was superior to IVM regarding immunostimulatory potency. In conclusion, DEC expressed an in vivo influence on the immune status during the infection by N. brasiliensis leading to retrogression of the mycetoma and increasing cellular immune responses. Our findings may indicate a potential use of DEC as a putative adjuvant in infectious disease or vaccination.

Clinical features and magnetic resonance image analysis of 15 cases of demyelinating leukoencephalopathy induced by levamisole

The aim of this study was to explore the diagnostic value of magnetic resonance imaging (MRI) for levamisole-induced demyelinating leukoencephalopathy. The clinical features and MRI findings of 15 patients with levamisole-induced demyelinating leukoencephalopathy were retrospectively analyzed. The abnormality rate of the patients was demonstrated to be 100% by MRI, and scattered multiple cerebral foci were observed in all of the patients. The majority of the foci were located at the centrum ovale, peri-lateral cerebral ventricles and basal ganglia, while the remainder were located in the brain stem and cerebellum, as well as in the white matter regions of the temporal, frontal, apical and occipital lobes. In addition, mottling and ring-shaped enhancements were observed. The study demonstrated that MRI effectively displays demyelinating leukoencephalopathy, and that the combination of MRI with the medical history of the patient is of significance for the early diagnosis, differentiation and treatment of demyelinating leukoencephalopathy.

Discovery of anthelmintic drug targets and drugs using chokepoints in nematode metabolic pathways

Parasitic roundworm infections plague more than 2 billion people (1/3 of humanity) and cause drastic losses in crops and livestock. New anthelmintic drugs are urgently needed as new drug resistance and environmental concerns arise. A “chokepoint reaction” is defined as a reaction that either consumes a unique substrate or produces a unique product. A chokepoint analysis provides a systematic method of identifying novel potential drug targets. Chokepoint enzymes were identified in the genomes of 10 nematode species, and the intersection and union of all chokepoint enzymes were found. By studying and experimentally testing available compounds known to target proteins orthologous to nematode chokepoint proteins in public databases, this study uncovers features of chokepoints that make them successful drug targets. Chemogenomic screening was performed on drug-like compounds from public drug databases to find existing compounds that target homologs of nematode chokepoints. The compounds were prioritized based on chemical properties frequently found in successful drugs and were experimentally tested using Caenorhabditis elegans. Several drugs that are already known anthelmintic drugs and novel candidate targets were identified. Seven of the compounds were tested in Caenorhabditis elegans and three yielded a detrimental phenotype. One of these three drug-like compounds, Perhexiline, also yielded a deleterious effect in Haemonchus contortus and Onchocerca lienalis, two nematodes with divergent forms of parasitism. Perhexiline, known to affect the fatty acid oxidation pathway in mammals, caused a reduction in oxygen consumption rates in C. elegans and genome-wide gene expression profiles provided an additional confirmation of its mode of action. Computational modeling of Perhexiline and its target provided structural insights regarding its binding mode and specificity. Our lists of prioritized drug targets and drug-like compounds have potential to expedite the discovery of new anthelmintic drugs with broad-spectrum efficacy.

The World Health Organization estimates that 2.9 million people are infected with parasitic roundworms, causing high-morbidity and mortality rates, developmental delays in children, and low productivity of affected individuals. The agricultural industry experiences drastic losses in crop and livestock due to parasitic worm infections. Therefore, there is an urgent need to identify new targets and drugs to fight parasitic nematode infection. This study identified metabolic chokepoint compounds that were either produced or consumed by a single reaction and elucidated the chokepoint enzyme that drives the reaction. If the enzyme that catalyzes that reaction is blocked, a toxic build-up of a compound or lack of compound necessary for subsequent reaction will occur, potentially causing adverse effects to the parasite organism. Compounds that target some of the chokepoint enzymes were tested in C. elegans and several compounds showed efficacy. One drug-like compound, Perhexiline, showed efficacy in two different parasitic worms and yielded expected physiological effects, indicating that this drug-like compound may have efficacy on a pan-phylum level through the predicted mode of action. The methodology to find and prioritize metabolic chokepoint targets and prioritize compounds could be applied to other parasites.

XIAP downregulation accompanies mebendazole growth inhibition in melanoma xenografts

Mebendazole (MBZ) was identified as a promising therapeutic on the basis of its ability to induce apoptosis in melanoma cell lines through a B-cell lymphoma 2 (BCL2)-dependent mechanism. We now show that in a human xenograft melanoma model, oral MBZ is as effective as the current standard of care temozolomide in reducing tumor growth. Inhibition of melanoma growth in vivo is accompanied by phosphorylation of BCL2 and decreased levels of X-linked inhibitor of apoptosis (XIAP). Reduced expression of XIAP on treatment with MBZ is partially mediated by its proteasomal degradation. Furthermore, exposure of melanoma cells to MBZ promotes the interaction of SMAC/DIABLO with XIAP, thereby alleviating XIAP's inhibition on apoptosis. XIAP expression on exposure to MBZ is indicative of sensitivity to MBZ as MBZ-resistant cells do not show reduced levels of XIAP after treatment. Resistance to MBZ can be reversed partially by siRNA knockdown of cellular levels of XIAP. Our data indicate that MBZ is a promising antimelanoma agent on the basis of its effects on key antiapoptotic proteins.

Clinical features and magnetic resonance image analysis of 15 cases of demyelinating leukoencephalopathy induced by levamisole

The aim of this study was to explore the diagnostic value of magnetic resonance imaging (MRI) for levamisole-induced demyelinating leukoencephalopathy. The clinical features and MRI findings of 15 patients with levamisole-induced demyelinating leukoencephalopathy were retrospectively analyzed. The abnormality rate of the patients was demonstrated to be 100% by MRI, and scattered multiple cerebral foci were observed in all of the patients. The majority of the foci were located at the centrum ovale, peri-lateral cerebral ventricles and basal ganglia, while the remainder were located in the brain stem and cerebellum, as well as in the white matter regions of the temporal, frontal, apical and occipital lobes. In addition, mottling and ring-shaped enhancements were observed. The study demonstrated that MRI effectively displays demyelinating leukoencephalopathy, and that the combination of MRI with the medical history of the patient is of significance for the early diagnosis, differentiation and treatment of demyelinating leukoencephalopathy.

Comparative effects of levamisole, Staphylococcus, and Freund's adjuvant on rat immunization with excretory and secretory antigens of Trichinella spiralis muscle larvae

A comparison was made of the effects of levamisole, the bacterial fractions of Staphylococcus, and Freund's adjuvant on the immunization of rats with the excretory and secretory antigens of Trichinella spiralis muscle larvae. Wistar rats were immunized with the antigen and a saline solution, levamisole (LV), Staphylococcus (ST), or Freund's adjuvant (FA). After immunization, rats were infected, and the parasite burden at muscular phase was calculated for each group. Levels of IgG1 and IgG2 antibodies, as well as levels of two cytokines, IL-4 and IFN-γ, were evaluated during the immunization and postinfection periods. Differences were found in the kinetics of antibody production between groups (p < 0.01). In all cases, there was reactivity with the main 45-, 50-, and 55-kDa antigens of Trichinella muscle larvae. Immunization with FA and ST enhanced the production of IgG1, but only FA showed a significant increase in the production of IFN-γ (p < 0.01), resulting in 86% protection against the infection. In contrast, only 60-70% protection was attained in the ST and LV groups (p < 0.01). These data support the idea that levamisole and Staphylococcus can be used as adjuvant to enhance the humoral response and, at the same time, demonstrate that IFN-γ could be involved in protection against Trichinella.

Associations between peripheral Plasmodium falciparum malaria parasitemia, human immunodeficiency virus, and concurrent helminthic infection among pregnant women in Malawi

Approximately 2 billion persons worldwide are infected with schistosomiasis and soil-transmitted helminths (STH), many in areas where endemic malaria transmission coexists. Few data exist on associations between these infections. Nested within a larger clinical trial, primigravid and secundigravid women provided blood samples for human immunodeficiency virus (HIV) testing and peripheral malaria films and stool and urine for evaluation of STH and Schistosoma spp. during their initial antenatal clinic visit. The most common parasitic infections were malaria (37.6%), S. haematobium (32.3%), and hookworm (14.4%); 14.2% of women were HIV-infected. S. haematobium infection was associated with lower malarial parasite densities (344 versus 557 parasites/μL blood; P < 0.05). In multivariate analysis, HIV and hookworm infection were independently associated with malaria infection (adjusted odds ratio = 1.9 and 95% confidence interval = 1.2-3.0 for HIV; adjusted odds ratio = 1.9 and 95% confidence interval = 1.03-3.5 for hookworm). Concurrent helminthic infection had both positive and negative effects on malaria parasitemia among pregnant women in Malawi.

CD4+CD25+ Treg induction by an HSP60-derived peptide SJMHE1 from Schistosoma japonicum is TLR2 dependent

Chronic schistosome infection results in the suppression of host immune responses, allowing long-term schistosome survival and restricting pathology. Current theories suggest that Treg play an important role in this regulation. However, the mechanism of Treg induction during schistosome infection is still unknown. The aim of this study was to determine the mechanism behind the induction of CD4(+)CD25(+) T cells by Schistosoma japonicum HSP60 (SjHSP60)-derived peptide SJMHE1 as well as to elucidate the cellular and molecular basis for the induction of CD4(+)CD25(+) T cells during S. japonicum infection. Mice immunized with SJMHE1 or spleen and LN cells from naïve mice pretreated with SJMHE1 in vitro all displayed an increase in CD4(+)CD25(+) T-cell populations. Release of IL-10 and TGF-beta by SJMHE1 stimulation may contribute to suppression. Adoptively transferred SJMHE1-induced CD4(+)CD25(+) T cells inhibited delayed-type hypersensitivity in BALB/c mice. Additionally, SJMHE1-treated APC were tolerogenic and induced CD4(+) cells to differentiate into suppressive CD4(+)CD25(+) Treg. Furthermore, our data support a role for TLR2 in SJMHE1-mediated CD4(+)CD25(+) Treg induction. These findings provide the basis for a more complete understanding of the S. japonicum-host interactions that contribute to host homeostatic mechanisms, preventing an excessive immune response.

Immunomodulatory activity of Zingiber officinale Roscoe, Salvia officinalis L. and Syzygium aromaticum L. essential oils: evidence for humor- and cell-mediated responses

OBJECTIVES

The immunomodulatory effect of ginger, Zingiber officinale (Zingiberaceae), sage, Salvia officinalis (Lamiaceae) and clove, Syzygium aromaticum (Myrtaceae), essential oils were evaluated by studying humor- and cell-mediated immune responses.

METHODS

Essential oils were administered to mice (once a day, orally, for a week) previously immunized with sheep red blood cells (SRBCs).

KEY FINDINGS

Clove essential oil increased the total white blood cell (WBC) count and enhanced the delayed-type hypersensitivity (DTH) response in mice. Moreover, it restored cellular and humoral immune responses in cyclophosphamide-immunosuppressed mice in a dose-dependent manner. Ginger essential oil recovered the humoral immune response in immunosuppressed mice. Contrary to the ginger essential oil response, sage essential oil did not show any immunomodulatory activity.

CONCLUSIONS

Our findings establish that the immunostimulatory activity found in mice treated with clove essential oil is due to improvement in humor- and cell-mediated immune response mechanisms.