Available online 13 November 2022, 108428

AbstractBackground

Cystic echinococcosis (CE), a widespread helminthic disease caused by the larval stage of the dog tapeworm Echinococcus granulosus represents a public health concern in humans. Albendazole (ABZ) is the first-line treatment for CE; however therapeutic failure of ABZ against CE occurs because of size and location of formed cysts as well its low aqueous solubility and consequently its erratic bioavailability in plasma. Serious adverse effects have also been observed following the long-term use of ABZ in vivo.

Methods

We evaluated the apoptotic effects of ABZ-loaded β-cyclodextrin (ABZ-β-CD) against protoscoleces (PSCs) versus ABZ alone. After 15 h of exposure, Caspase-3 enzymatic activity was determined by fluorometric assay in PSCs treated with ABZ and ABZ-β-CD groups. To assess the treatment efficacy of ABZ-β-CD against PSCs, mRNA expression of Arginase (EgArg) and Thioredoxin peroxidase (EgTPx) were quantified by Real-time PCR.

Results

A significant scolicidal activity of ABZ was observed only at a concentration of 800 μg/mL (100% PSCs mortality rate after 4 days of exposure), while the 200 and 400 μg/mL ABZ reached 100% PSCs mortality rate after 9 sequential days. The 400 μg/mL ABZ-β-CD had 100% scolicidal rate after 5 days of exposure. Morphological alterations using scanning electron microscopy in treated PSCs revealed that 400 μg/mL ABZ-β-CD induced higher Caspase-3 activity than their controls, indicating a more potent apoptotic outcome on the PSCs. Also, we showed that the 400 μg/mL ABZ-β-CD can down-regulate the mRNA expression of EgArg and EgTPx, indicating more potent interference with growth and antioxidant properties of PSCs.

Conclusions

In the present study, a significant scolicidal rate, apoptosis intensity and treatment efficacy was observed in PSCs treated with 400 μg/mL ABZ-β-CD compared to ABZ alone. This provides new insights into the use of nanostructured β-CD carriers with ABZ as a promising candidate to improve the treatment of CE in in vivo models.

Section snippetsBackground

Cystic echinococcosis (CE) is a neglected helminthic infection with significant impacts on human health caused by the larval stages of Echinococcus granulosus sensu lato (s.l.) (Casulli et al., 2019; Eckert and Deplazes, 2004). Canids harboring adult worms of E. granulosus s.l. excrete echinococcal eggs into the environment, where humans and animals may be infected via the ingestion of the eggs. Once ingested, the oncospheres in the eggs hatch, penetrate the intestinal wall of the host and

Preparation of ABZ-loaded β-CD

ABZ and β-CD were purchased from Sigma-Aldrich Chemie GmbH (Steinheim, Germany). Hundred mg of β-CD were dissolved in 16 mL deionized water; then 30 mg of ABZ was solubilized in dimethyl sulfoxide (DMSO). The solutions were mixed and placed on the stirrer at 400 rpm for 24 h to evaporate the DMSO without a cap. Afterward, it was centrifuged at 10,000 rpm for 5 min and supernatant was collected.

Encapsulation and characterization of ABZ-β-CD

The morphological structure of the ABZ-β-CD was detected by scanning electron microscopy (SEM). One mg

FTIR spectroscopy, zeta potential, particle size and SEM analyze

FTIR spectroscopy was employed to demonstrate the structure of ABZ (Fig. 2A), β-CD and ABZ-β-CD (Fig. 2B and C). The FTIR spectra of these polymers showed a broad absorption at 3334 cm−1 representing the presence of –OH radicals. Also, absorption at 2920 cm−1 indicated the presence of –CH radicals and the absorption band at 1030–1092 cm −1 confirmed the formation of C–O–C ether bond. Absorption at 1635 cm−1 showed the presence of CO radicals and absorption at 2162 cm−1 demonstrated the presence

Discussion

The present study, aimed to increase the treatment efficacy of ABZ against PSCs of E. granulosus s.s. We therefore compared the in vitro scolicidal and apoptotic properties of ABZ versus ABZ-β-CD. Limitations observed in the ABZ formulation, such as the parasitostatic effect and possible drug resistance to BMZs have lead to the importance of nanomedicine for developing fine-tuned formulations including solubility and stability of ABZ as long-term delivery systems (Bakhtiar et al., 2019;

Conclusions

In the present study, a significant scolicidal rate, apoptosis intensity and treatment efficacy was observed in PSCs treated with 400 μg/mL ABZ-β-CD compared to ABZ alone. This effective dose provides new insights into the use of nanostructured β-CD carriers of ABZ as a promising candidate to improve the treatment of CE in in vivo models.

Funding

This study was financially supported by Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran (Grant no. 59631).

Availability of data and materials

Data supporting the conclusions of this article are included within the article.

Authors’ contributions

NMB&AS&NA: carried out the molecular genetic studies and have been involved in drafting the manuscript. MMO&EH&AK&RN: participated in the design of the study, contributed to data collection and helped to draft the manuscript. AC&MA&ME: performed the statistical analysis and have been involved in critically revising the manuscript for important intellectual content. All authors read and approved the final version of the manuscript.

Ethics approval and consent to participate

IR.TBZMED.VCR.REC.1397.050.

Consent for publication

Not applicable.

Declaration of competing interest

The authors declare that they have no conflict of interests.

Acknowledgments

This is a report of a database from the thesis of Miss Nayer Mehdizad Bakhtiar registered in Tabriz University of Medical Sciences. This work was also partially supported by ERANet-LAC 2nd Joint Call (http://www.eranet-lac.eu) and the Italian Ministry of Health-NDTND project.

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