Topical ivermectin 1.0% cream in the treatment of ocular demodicosis

PURPOSE

Ocular demodicosis can cause debilitating ocular surface disease. As ivermectin is effective at reducing Demodex proliferation in rosacea, this study investigated the efficacy of topical ivermectin 1.0% cream in treating ocular demodicosis.

METHODS

This retrospective single-centre clinical practice chart analysis involved the off-label treatment of patients who had ocular demodicosis with topical ivermectin 1.0 % cream (Soolantra, Galderma Ltd, UK) applied nightly to the lid margins of both eyes for 3 months. Ocular surface health was assessed at baseline when the treatment was prescribed and followed up at 3 and 12 months after baseline. Slit lamp biomicroscopy was used to take digital images of the upper eyelid lashes. Manual image analysis with ImageJ was conducted by a masked assessor to quantify signs of ocular demodicosis including the number of lashes with collarettes, with visible Demodex tails and with follicle pouting.

RESULTS

Data from a total of 75 patients with ocular demodicosis were analysed for this study (mean age 66.6 ± 13.9 years, 44 female). The numbers of lashes with collarettes (Median [Interquartile range]: 8 [4-13] at baseline to 0 [0-2] at the final visit, p < 0.001) and lashes with follicle pouting (3 [1-5] at baseline to 0 [0-1.8] at the final visit, p < 0.001) decreased with treatment. Any sign of lashes with visible tails was eliminated by the final visit (p < 0.007). Fluorescein staining severity score also improved, particularly from baseline (1 [0-2]) to the second visit (0 [0-1], p < 0.001).

CONCLUSIONS

The findings of this study show evidence for the efficacy of a 3-month course of topical ivermectin 1.0% cream in treating ocular demodicosis as indicated by reduction in collarettes, follicle pouting and visible Demodex tails. More research is warranted to improve the diagnosis, management and monitoring of this condition which is often overlooked or misdiagnosed.

Tubulin inhibitors. Selected scaffolds and main trends in the design of novel anticancer and antiparasitic agents

Design of tubulin inhibitors as anticancer drugs dynamically developed over the past 20 years. The modern arsenal of potential tubulin-targeting anticancer agents is represented by small molecules, monoclonal antibodies, and antibody-drug conjugates. Moreover, targeting tubulin has been a successful strategy in the development of antiparasitic drugs. In the present review, an overall picture of the research and development of potential tubulin-targeting agents using small molecules between 2018 and 2023 is provided. The data about some most often used and prospective chemotypes of small molecules (privileged heterocycles, moieties of natural molecules) and synthetic methodologies (analogue-based, fragment-based drug design, molecular hybridization) applied for the design of novel agents with an impact on the tubulin system are summarized. The design and prospects of multi-target agents with an impact on the tubulin system were also highlighted. Reported in the review data contribute to the "structure-activity" profile of tubulin-targeting small molecules as anticancer and antiparasitic agents and will be useful for the application by medicinal chemists in further exploration, design, improvement, and optimization of this class of molecules.

The discovery of aryl-2-nitroethyl triamino pyrimidines as anti-Trypanosoma brucei agents

Pteridine reductase 1 (PTR1) is a catalytic protein belonging to the folate metabolic pathway in Trypanosmatidic parasites. PTR1 is a known target for the medicinal chemistry development of antiparasitic agents against Trypanosomiasis and Leishmaniasis. In previous studies, new nitro derivatives were elaborated as PTR1 inhibitors. The compounds showing a diamino-pyrimidine core structure were previously developed but they showed limited efficacy. Therefore, a new class of phenyl-, heteroaryl- and benzyloxy-nitro derivatives based on the 2-nitroethyl-2,4,6-triaminopyrimidine scaffold were designed and tested. The compounds were assayed for their ability to inhibit T. brucei and L. major PTR1 enzymes and for their antiparasitic activity towards T. brucei and L. infantum parasites. To understand the structure-activity relationships of the compounds against TbPTR1, the X-ray crystallographic structure of the 2,4,6-triaminopyrimidine (TAP) was obtained and molecular modelling studies were performed. As a next step, only the most effective compounds against T. brucei were then tested against the amastigote cellular stage of T. cruzi, searching for a broad-spectrum antiprotozoal agent. An early ADME-Tox profile evaluation was performed. The early toxicity profile of this class of compounds was investigated by measuring their inhibition of hERG and five cytochrome P450 isoforms (CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4), cytotoxicity towards A549 cells and mitochondrial toxicity. Pharmacokinetic studies (SNAP-PK) were performed on selected compounds using hydroxypropyl-β-cyclodextrins (50 % w/v) to preliminarily study their plasma concentration when administered per os at a dose of 20 mg/kg. Compound 1p, showed the best pharmacodynamic and pharmacokinetic properties, can be considered a good candidate for further bioavailability and efficacy studies.

Evidence-based indications for ivermectin in parasitic diseases: An integrated approach to context and challenges in Peru

Ivermectin has emerged as a therapeutic option for various parasitic diseases, including strongyloidiasis, scabies, lice infestations, gnathostomiasis, and myiasis. This study comprehensively reviews the evidence-based indications for ivermectin in treating parasitic diseases, considering the unique context and challenges in Peru. Fourteen studies were selected from a systematic search of scientific evidence on ivermectin in PubMed, from 2010 to July 2022. The optimal dosage of ivermectin for treating onchocerciasis, strongyloidiasis, and enterobiasis ranges from 150 to 200 μg/kg, while lymphatic filariasis requires a higher dose of 400 μg/kg (Brown et al., 2000). However, increased dosages have been associated with a higher incidence of ocular adverse events. Scientific evidence shows that ivermectin can be safely and effectively administered to children weighing less than 15 kg. Systematic reviews and meta-analyses provide strong support for the efficacy and safety of ivermectin in combating parasitic infections. Ivermectin has proven to be an effective treatment for various parasitic diseases, including intestinal parasites, ectoparasites, filariasis, and onchocerciasis. Dosages ranging from 200 μg/kg to 400 μg/kg are generally safe, with adjustments made according to the specific pathology, patient age, and weight/height. Given Peru's prevailing social and environmental conditions, the high burden of intestinal parasites and ectoparasites in the country underscores the importance of ivermectin in addressing these health challenges.

Botanicals against some important nematodal diseases: Ascariasis and hookworm infections

Ascariasis and intestinal parasitic nematodes are the leading cause of mass mortality infecting many people across the globe. In light of the various deleterious side effects of modern chemical-based allopathic drugs, our preferences have currently shifted towards the use of traditional plant-based drugs or botanicals for treating diseases. The defensive propensities in the botanicals against parasites have probably evolved during their co-habitation with parasites, humans and plants in nature and hence their combative interference in one another's defensive mechanisms has occurred naturally ultimately being very effective in treating diseases. This article broadly outlines the utility of plant-based compounds or botanicals prepared from various medicinal herbs that have the potential to be developed as effective therapies against the important parasites causing ascariasis and intestinal hookworm infections leading to ascariasis & infections and thereby human mortality, wherein allopathic treatments are less effective and causes enormous side-effects.

PRESCRIBING PATTERNS AND THE USE OF ANTHELMINTIC DRUGS IN COLOMBIAN PATIENTS: A CROSS-SECTIONAL STUDY

Intestinal parasites continue to be a public health problem in low- and middle-income countries. Broad use of anthelmintics during deworming programs is still necessary in many regions. However, description of the usage of these medications in general medical practice has been limited. The objective of this study was to determine the use of anthelmintic drugs and their indications in a group of Colombian patients. This was a descriptive study from a drug-dispensing database, identifying patients with prescriptions for anthelmintic drugs. A total of 381 cases were randomly selected, and their medical records were reviewed, analyzing sociodemographic, clinical, and pharmacological variables (indication of use). The lack of diagnosis registration or clinical manifestations of parasites was determined as a prescription without indication. In total, 50.9% (n = 194) of patients were female, and 67.4% of all patients were under 18 yr of age. The diagnosis of helminthiases was clearly stated in 114 (29.9%) patients, and only 4.2% (n = 16) of these had microbiological confirmation. The most commonly used anthelmintic drug was albendazole (70.4% of all prescriptions). The use of anthelmintics was not indicated in 266 cases (69.8%). Nutritional supplements or vitamin prescriptions were associated with using anthelmintics without indication (odds ratio: 2.25; 95% confidence interval: 1.26-4.03). A high proportion of patients lacked symptoms or diagnoses in their clinical records that supported the use of anthelmintic drugs.

Design and synthesis of novel bis-pyridinium based-ionic liquids as potent antiparasitic agents

Focused bis-pyridinium based-ionic liquids were successfully synthesized through the quaternization of the selected 1,2-di(pyridin-4-yl)ethane followed by metathetical anion exchange. The synthesized pyridinium derivatives were fully characterized using various NMR-spectroscopic techniques including ¹H, ¹³C, ¹¹B, ³¹P and ¹⁹F NMR. The synthesized compounds were tested for their potential effect against Toxoplasma gondii. It was revealed that compound 5 had higher antiparasitic activity compared to other compounds. Parasitic reduction percentage reached 38, 50, 77 and 79 for groups III, IV, V and VI respectively in the liver with noticed distortion and deformation in tachyzoites' shape. Surprisingly there was no statistically significant difference between the synthesized compound 5 and the known anti-toxoplasmosis drug pyrimethamine. Histopathological study proved the effectiveness of the synthesized compound 5 on liver, spleen and brain tissues with observed better histological features compared to pyrimethamine treated group. The present investigation may pave the way to the possible use of compound 5 to replace the known drug pyrimethamine with better antiparasitic profile and fewer side effects.

A 20 Years Retrospective Descriptive Study of Human Cystic Echinococcosis and the Role of Albendazole Concurrent with Surgical Treatment: 2001-2021

Background

Hydatid cyst, caused by the larvae of Echinococcus granulosus, is one of the most severe cestode infections occurring in Iran. The liver is the most commonly involved organ. The present study was carried out to review the demographic of 20 years surgically treated hydatic cysts.

Methods

Ninety-eight patients were enrolled in the study. Demographic features, time of surgery, cyst size, and albendazole usage have been reviewed from the medical records of patients in Loghman Hakim Hospital, Tehran, Iran, from 2001 to 2021. Statistical analysis was performed to find any correlation between the uses of concurrent albendazole with surgical procedure.

Results

Of 98 patients with hydatid cyst, 57 (58.2%) were female. The mean age of patients was 39.4 ±18.7 yrs, and the mean surgery time was 217.5 ± 81.4 minutes. Regarding the infection site, the liver (60.2%) and lungs (22.4%) were the most affected organs, respectively. 56.1% of patients had one cyst, and 42.9 % had two or more cysts. 20.4% of them had taken albendazole before surgery, but 86.7 % took it after the operation. No recurrent cysts were seen among 91.8% of them, but 8.2% mentioned suffering from a recurrent cyst. 85.7% of those recurrent cases did not receive albendazole before surgery, and 75% of recurrent cases after surgery did not take albendazole (P<0.05).

Conclusion

Administration of albendazole before and after the operation was significantly related to reduced recurrence, bleeding, morbidity, and even the time of surgery.

In Vitro and In Vivo Anti-Toxoplasma Activities of Dracocephalum kotschyi Extract in Experimental Models of Acute Toxoplasmosis

BACKGROUND

The problem of resistance to antiparasitic drugs, associated with their side effects, suggest exploring other alternatives, including medicinal plants. Dracocephalum kotschyi (D. kotschyi), for example, from Lamiaceae family, is a plant widely used in Iran and in many countries, and to which interesting pharmacological properties have been attributed. This study aimed to investigate in vitro and in vivo anti-Toxoplasma activities of D. kotschyi extract in experimental models of acute toxoplasmosis.

METHODS

Anti-Toxoplasma activity of the extracts in vitro was performed on Vero Cell, using the MTT test. Vero cell were infected with (3 × 10⁵ tachyzoites/well) following treatment with Dichloromethane (F1), dichloromethane: methanol (F2), methanol (F3), methanol: water (F4), and deionized water (F5) extracts of D. kotschyi, and pyrimethamine and sulfadiazine (positive control). MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was used to measure cell viability. Effects of extracts on tachyzoites viability were evaluated by trypan blue exclusion method, followed by light microscopy. For in vivo test, 18 groups of 8-10-week-old Inbred Balb/c mice weighing 18-20 g, were intraperitoneally infected with 2 × 10³ tachyzoites and then treated with sterile PBS (negative control), pyrimethamine (25 mg/kg) and sulfadiazine (500 mg/kg) as positive controls, and F1 to F5 extracts (at doses 50, 100 and 200 mg/kg).

RESULTS

The 50% Inhibitory Concentration of F1 extract, F2 extract, Sulfadiazine (Positive control) and Pyrimethamine (Positive control) were 8.77 µg, 7.1 µg 391.18 µg, and 84.20 µg, respectively, while the selectivity indices were 15.667, 30.197, 1.552 and 4.064, respectively. In vivo anti-Toxoplasma activity test showed that Methanol: water (F-4) 50 extract was more active than the positive control.

CONCLUSIONS

Indeed, the extract allowed a survival rate of 10% of the mice, compared to 0% for all the other groups. D. kotschyi has the potential to be valorized in the management of toxoplasmosis.

Trypanocidal treatment of Chagas disease

Chagas disease is a neglected parasitosis caused by the protozoan parasite Trypanosoma cruzi. This infection is present in most Latin American countries, although, due to migratory movements, it is a growing cause for concern in non-endemic countries. The only two drugs currently available for its treatment-benznidazole and nifurtimox-were marketed 50 years ago. While they are very effective for acute and recent infection, and for the prevention of maternofoetal transmission, their efficacy declines in people who have chronic infection, especially those older than 18 years of age. In the presence of visceral involvement, parasiticidal treatment is of little or no value. The safety profile of both drugs is far from ideal, with frequent adverse events and high rates of drug discontinuation, mainly in adults. So far, new drugs and new strategies have not been shown to improve the results of the current nitroimidazoles, although the results are promising. In this review, we focus on the aspects that allow clinicians to make the best use of currently available drugs. In addition, we discuss new therapeutic options and ongoing research in the field.

Trypanocidal treatment of Chagas disease

Chagas disease is a neglected parasitosis caused by the protozoan parasite Trypanosoma cruzi. This infection is present in most Latin American countries, although, due to migratory movements, it is a growing cause for concern in non-endemic countries. The only two drugs currently available for its treatment-benznidazole and nifurtimox-were marketed 50 years ago. While they are very effective for acute and recent infection, and for the prevention of maternofoetal transmission, their efficacy declines in people who have chronic infection, especially those older than 18 years of age. In the presence of visceral involvement, parasiticidal treatment is of little or no value. The safety profile of both drugs is far from ideal, with frequent adverse events and high rates of drug discontinuation, mainly in adults. So far, new drugs and new strategies have not been shown to improve the results of the current nitroimidazoles, although the results are promising. In this review, we focus on the aspects that allow clinicians to make the best use of currently available drugs. In addition, we discuss new therapeutic options and ongoing research in the field.

Phosphatidic acid homeostasis regulated by a type-2 phosphatidic acid phosphatase represents a novel druggable target in malaria intervention

Type-2 phosphatidic acid phosphatase (PAP2) a member of PAP2 superfamily mediates the conversion of phosphatidic acid (PA) to diacylglycerol (DAG) and thus plays a pivotal role in numerous cellular signaling processes in diverse organisms. An elevated level of intracellular PA is detrimental for the cell and induces cell death. In this study we identified and characterized a PAP2 homologue in Plasmodium falciparum, PfPAP2 and further elucidated its significance in regulation of PA homeostasis in parasite life cycle. PfPAP2 is expressed in the blood stage and harbors the canonical acid phosphatase domain (APD) with signature motifs. PfPAP2 catalyzes the dephosphorylation of PA to produce DAG and inorganic phosphate (P_i). Propranolol, a generic inhibitor of PAP2, inhibited the phosphatase activity of PfPAP2 by binding to the active site of APD domain as evident by in silico docking and confirmed by surface plasmon resonance (SPR) analysis. Inhibition of native PfPAP2 by propranolol led to rise in intracellular PA mediating disruption of intracellular PA homeostasis in parasites. The propranolol mediated inhibition of PfPAP2 directed early secretion of a micronemal Perforin like Protein, PfPLP1 leading to untimely permeabilization and host cell egress. The merozoites following premature egress were non-invasive and were attenuated to invade erythrocytes and cannot continue next cycle growth. This study demonstrates that disruption of PA homeostasis can cause growth retardation in malaria parasites, and thus its master regulator, PfPAP2, can serve as a very good molecular target for antimalarial chemotherapeutic interventions.

Curcumin induced oxidative stress causes autophagy and apoptosis in bovine leucocytes transformed by Theileria annulata

Bovine tropical theileriosis is a tick-borne disease, caused by Theileria annulata which is a protozoan parasite that resides within the B-cells and macrophages. T. annulata is a unique parasite that can transform bovine leucocytes which leads to the cancer hallmarks in the infected cells. Previously, curcumin has been shown to possess multiple pharmacological activities such as anti-inflammatory and anti-cancer activities. In this study, we demonstrated that curcumin inhibits the proliferation of Theileria-transformed bovine leucocytes by promoting apoptosis and autophagy. The transcriptome analysis of curcumin treated cells showed that the genes involved in cell death and autophagy are also differentially regulated. We further elucidated the mechanism of action of curcumin on Theileria infected bovine cells. We found that curcumin induced the generation of reactive oxygen species (ROS) which activated caspase 8 and destabilized the mitochondrial membrane potential leading to the release of cytochrome c from mitochondria. This subsequently led to the activation of caspase 3 and PARP cleavage, finally leading to apoptosis in the infected cells. Furthermore, curcumin induced the process of autophagy which was characterized by the formation of acidic vesicular organelles, LC3B accumulation with lysosome inhibitor, E64d, and the presence of autophagosomes as visualized by transmission electron microscopy (TEM). Curcumin treatment suppressed the mTOR and increased the expression of autophagy-related proteins. We also found that N- acetylcysteine, an inhibitor of ROS, could rescue the infected cells from curcumin induced apoptosis and autophagy mediated cell death. Intriguingly, curcumin had no effect on uninfected bovine PBMCs. Altogether, these data suggest the therapeutic potential of curcumin against bovine tropical theileriosis.

Control of fly strike dermatitis in dogs with a topically applied combination of imidacloprid and permethrin: a prospective open-label controlled clinical trial

Background

A prospective clinical study evaluated the tolerance and the efficacy of a combination of imidacloprid (10%) and permethrin (50%) (ADVANTIX^®: Bayer HC AH, France) applied topically as a spot-on, for the treatment of natural canine fly dermatitis due to Stomxys calcitrans. The study was an open-label controlled study and one-month follow-up.

Methods

Fifteen dogs, from the same animal kennel, with active pinnal lesions of fly dermatitis, received a single application of the solution on the cranium and the base of the ears on Day 0 (D0). Five dogs, from the same kennel, similarly affected, served as non-treated controls. No other therapeutical or hygienic measures were taken. Lesional score was based on extension, alopecia, crusts, scales, erosions/ulcers, loss of substance and lichenification, each assessed on a 0–4 scale. Evaluation was performed on D0, D14 and D30. Total lesion score reduction was calculated at each time point using the arithmetic mean of total lesion score according to Abbott’s formula. Scores obtained on D14 and D30 were compared with the baseline obtained on D0.

Results

No adverse event was recorded. The lesion score ranged between 4–13 at D0 in all dogs. In control dogs, D0 mean (± SD) lesion score was 7 ± 1.4. Lesion scores were maintained on D14 (6.6 ± 3.4) and D30 (8.6 ± 5.4). In treated dogs, D0 mean lesion score was 9.9 ± 2.5. Lesion scores of the treated dogs were reduced by 59% on D14 (4.1 ± 2.8) and 80% on D30 (1.9 ± 1.5) (P < 0.05).

Conclusions

The combination imidacloprid-permethrin proved safe and helpful in the management of natural canine fly dermatitis. It could also be suggested as a preventive measure with a monthly application during the fly exposition phase.

Trypanocidal activity of mastoparan from Polybia paulista wasp venom by interaction with TcGAPDH

Chagas disease, considered a neglected disease, is a parasitic infection caused by Trypanosoma cruzi, which is endemic throughout the world. Previously, the antimicrobial effect of Mastoparan (MP) from Polybia paulista wasp venom against bacteria was described. To continue the study, we report in this short communication the antimicrobial effect of MP against Trypanosoma cruzi. MP inhibits all T. cruzi developmental forms through the inhibition of TcGAPDH suggested by the molecular docking. In conclusion, we suggest there is an antimicrobial effect also on T. cruzi.

Antiparasitic Lead Discovery: Toward Optimization of a Chemotype with Activity Against Multiple Protozoan Parasites

Human African trypanosomiasis (HAT), Chagas disease, and leishmaniasis present a significant burden across the developing world. Existing therapeutics for these protozoal neglected tropical diseases suffer from severe side effects and toxicity. Previously, NEU-1045 (3) was identified as a promising lead with cross-pathogen activity, though it possessed poor physicochemical properties. We have designed a library of analogues with improved calculated physicochemical properties built on the quinoline scaffold of 3 incorporating small, polar aminoheterocycles in place of the 4-(3-fluorobenzyloxy)aniline substituent. We report the biological activity of these inhibitors against Trypanosoma brucei (HAT), T. cruzi (Chagas disease), and Leishmania major (cutaneous leishmaniasis) and describe the identification of N-(5-chloropyrimidin-2-yl)-6-(4-(morpholinosulfonyl)phenyl)quinolin-4-amine (13t) as a promising inhibitor of L. major proliferation and 6-(4-(morpholinosulfonyl)phenyl)-N-(pyrimidin-4-yl)quinolin-4-amine (13j), a potent inhibitor of T. brucei proliferation with improved drug-like properties.

New insights into molecular recognition of 1,1-bisphosphonic acids by farnesyl diphosphate synthase

As part of our project pointed at the search of new antiparasitic agents against American trypanosomiasis (Chagas disease) and toxoplasmosis a series of 2-alkylaminoethyl-1-hydroxy-1,1-bisphosphonic acids has been designed, synthesized and biologically evaluated against the etiologic agents of these parasitic diseases, Trypanosoma cruzi and Toxoplasma gondii, respectively, and also towards their target enzymes, T. cruzi and T. gondii farnesyl pyrophosphate synthase (FPPS), respectively. Surprisingly, while most pharmacologically active bisphosphonates have a hydroxyl group at the C-1 position, the additional presence of an amino group at C-3 resulted in decreased activity towards either T. cruzi cells or TcFPPS. Density functional theory calculations justify this unexpected behavior. Although these compounds were devoid of activity against T. cruzi cells and TcFPPS, they were efficient growth inhibitors of tachyzoites of T. gondii. This activity was associated with a potent inhibition of the enzymatic activity of TgFPPS. Compound 28 arises as a main example of this family of compounds exhibiting an ED₅₀ value of 4.7 μM against tachyzoites of T. gondii and an IC₅₀ of 0.051 μM against TgFPPS.

Design, synthesis and biological evaluation of WC-9 analogs as antiparasitic agents

As a part of our project pointed at the search of new safe chemotherapeutic and chemoprophylactic agents against parasitic diseases, several compounds structurally related to 4-phenoxyphenoxyethyl thiocyanate (WC-9), which were modified at the terminal aromatic ring, were designed, synthesized and evaluated as antiproliferative agents against Trypanosoma cruzi, the parasite responsible of American trypanosomiasis (Chagas disease) and Toxoplasma gondii, the etiological agent of toxoplasmosis. Most of the synthetic analogs exhibited similar antiparasitic activity being slightly more potent than the reference compound WC-9. For example, the nitro derivative 13 showed an ED₅₀ value of 5.2 μM. Interestingly, the regioisomer of WC-9, compound 36 showed similar inhibitory action than WC-9 indicating that para-phenyl substitution pattern is not necessarily required for biological activity. The biological evaluation against T. gondii was also very promising. The ED₅₀ values corresponding for 13, 36 and 37 were at the very low micromolar level against tachyzoites of T. gondii.