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

Triclabendazole efficacy, prevalence, and re-infection of Fasciola hepatica in bovine and ovine naturally infected in the Andes of Ecuador

Fasciola spp., infections are distributed worldwide including the Andes region of Ecuador, affecting cattle, sheep, porcine, humans, and other herbivores. Triclabendazole (TCBZ) is commonly used to treat animal infections. However, prospective studies on TCBZ efficacy and fascioliosis prevalence have not been studied in the highlands of Ecuador. This study was performed in a rural community at central of the Ecuadorian Andes in freely roaming bovine and ovine aimed to 1) evaluate the efficacy of TCBZ by administering a single oral dose of 12 mg/kg body weight, 2) assess the prevalence of F. hepatica infection and 3) to monitor re-infections for a follow-up period of five months. In total, 122, 86, 111, 110, 89, and 90 and 49, 34, 47, 28, 27, and 31 stool samples were collected each month from bovines and ovine, respectively. Besides, 32 stool samples from porcine were also collected at the beginning of the study. Stools were microscopically analyzed by formalin-ether concentration method to detect F. hepatica ova. The prevalence of F. hepatica infections before treatment was 55,7% and 63,3% for bovine and ovine, respectively. The infection prevalence was of 22% in porcine. The efficacity of triclabendazole was 83% and 97% in bovines and ovine, respectively, at 30 days post-treatment. The re-infection reaches to 54,4% in bovines and 61,3% in ovine after five months. TCBZ had a high efficacy and could be used for bovines and ovine Fasciola infections in the study region; however, re-infections reach the initial prevalence after five months. Therefore, we recommend integrated control strategies, including chemotherapy with a single oral dose of TCBZ, vector control, and future drug resistance studies.

Pivotal role of permeability-glycoprotein in absorption of praziquantel into Dicrocoelium dendriticum parasite

Dicrocoelium dendriticum affects the livers of ruminants and causes several deleterious effects on animal health status. The aim of this study was to investigate the role of permeability-glycoprotein (P-gp) in absorption of praziquantel (PZQ) into D. dendriticum flukes by co-incubation with verapamil (VPL), an inhibitor of P-gp, under in vitro conditions. Mature flukes of D. dendriticum were collected from naturally infected sheep livers. The flukes were incubated with different concentrations of PZQ and VPL (50 and 100 μg/ml) in culture media and after several times of exposure (2, 6, 12, and 24 h), the concentration of PZQ absorbed in the parasites was measured by high-performance liquid chromatography. At 2-h post-incubation, the highest concentration of PZQ was noted as 0.92 µg/ml in the flukes treated with 100 μg/ml of each PZQ and VPL. After 24-h of exposure, VPL at all tested concentrations resulted in significant increase in absorption of PZQ into the parasite. Co-incubation of lancet flukes with VPL and PZQ roughly doubled the absorption of PZQ into them. Results of tegumental structures analysis by light microscopy confirmed higher efficacy of combination of VPL and PZQ. In conclusion, co-administration of VPL, especially at the concentration of 100 μg/ml, was able to increase PZQ uptake in Dicrocoelium flukes at all time points of the study.

Simultaneous analysis of the of levamisole with triclabendazole in pharmaceuticals through developing TLC and HPLC-PDA chromatographic techniques and their greenness assessment using GAPI and AGREE methods

Two simple and rapid chromatographic methods were developed and validated for the analysis of levamisole and triclabendazole simultaneously in pure and pharmaceutical products. The first method is thin-layer chromatography (TLC) with densitometry, and the second method is high-performance liquid chromatography with PDA detection (HPLC-PDA). A Hypersil BDS C18 column with dimensions of 4.6 × 150 mm and a particle size of 5 µm was used in the HPLC-PDA method. An isocratic condition was used to carry out the separation, and the mobile phase was made up of acetonitrile and a 0.03 M potassium dihydrogen phosphate buffer in double-distilled water. The ratio of the mobile phase preparation was 70:30 (v/v), and the flow rate was 1 mL/min. A wavelength of 215 nm was employed for analyte detection. Precoated silica gel 60 F254 aluminium plates were used for the TLC method's separation. Mobile phase was made of ethyl acetate, hexane, methanol, and ammonia (69:15:15:1) for the separation. The detection wavelength selected was 215 nm. According to the International Council for Harmonization (ICH) guidelines, the proposed methods were validated and it was found that the two chromatographic methods are accurate, precise, and linear for both compounds in the range of 3.75-37.5 and 6-60 mg/L for the HPLC method for levamisole and triclabendazole, respectively and in the range of 2-14 µg/spot for the TLC method. The developed methods greenness profile was assessed using AGREE and ComplexGAPI tools.

In vitro anti-Leishmania activity of triclabendazole and its synergic effect with amphotericin B

Introduction

Leishmaniasis is a neglected tropical disease, with approximately 1 million new cases and 30,000 deaths reported every year worldwide. Given the lack of adequate medication for treating leishmaniasis, drug repositioning is essential to save time and money when searching for new therapeutic approaches. This is particularly important given leishmaniasis's status as a neglected disease. Available treatments are still far from being fully effective for treating the different clinical forms of the disease. They are also administered parenterally, making it challenging to ensure complete treatment, and they are extremely toxic, in some cases, causing death. Triclabendazole (TCBZ) is a benzimidazole used to treat fasciolosis in adults and children. It presents a lower toxicity profile than amphotericin B (AmpB) and is administered orally, making it an attractive candidate for treating other parasitoses. The mechanism of action for TCBZ is not yet well understood, although microtubules or polyamines could potentially act as a pharmacological target. TCBZ has already shown antiproliferative activity against T. cruzi, T. brucei, and L. infantum. However, further investigations are still necessary to elucidate the mechanisms of action of TCBZ.

Methods

Cytotoxicity assay was performed by MTT assay. Cell inhibition (CI) values were obtained according to the equation CI = (O.D treatment x 100/O.D. negative control). For Infection evaluation, fixated cells were stained with Hoechst and read at Operetta High Content Imaging System (Perkin Elmer). For growth curves, cell culture absorbance was measured daily at 600 nm. For the synergism effect, Fractional Inhibitory Concentrations (FICs) were calculated for the IC50 of the drugs alone or combined. Mitochondrial membrane potential (DYm), cell cycle, and cell death analysis were evaluated by flow cytometry. Reactive oxygen species (ROS) and lipid quantification were also determined by fluorimetry. Treated parasites morphology and ultrastructure were analyzed by electron microscopy.

Results

The selectivity index (SI = CC50/IC50) of TCBZ was comparable with AmpB in promastigotes and amastigotes of Leishmania amazonensis. Evaluation of the cell cycle showed an increase of up to 13% of cells concentrated in S and G2, and morphological analysis with scanning electron microscopy showed a high frequency of dividing cells. The ultrastructural analysis demonstrated large cytoplasmic lipid accumulation, which could suggest alterations in lipid metabolism. Combined administration of TCBZ and AmpB demonstrated a synergistic effect in vitro against intracellular amastigote forms with cSFICs of 0.25.

Conclusions

Considering that TCBZ has the advantage of being inexpensive and administrated orally, our results suggest that TCBZ, combined with AmpB, is a promising candidate for treating leishmaniasis with reduced toxicity.