Synthesis, characterization, and in vitro activity of piperine nanocrystals against protoscoleces of Echinococcus granulosus

Despite recent advances, current treatments for cystic echinococcosis (CE) still face challenges because of significant adverse effects and complications. This study investigates the synthesis, characterization, and in vitro activity of piperine nanocrystals (PIP-NCs) against E. granulosus protoscoleces. PIP-NCs were prepared by adding PIP to a solution of Tween 80 and polyvinyl alcohol (PVA) in distilled water using an emulsion–nanoprecipitation method. The morphological and chemical characterization of PIP-NCs was performed using field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), ultraviolet-visible (UV-Vis) spectrophotometry, and Fourier-transform infrared spectroscopy (FTIR). The cytotoxicity assessment was performed using the MTT reduction assay on L929 fibroblast cells. E. granulosus protoscoleces were exposed to four concentrations of PIP-NCs (125, 250, 500, and 750 µg/mL) for durations of 5, 10, 20, 30, 60, and 120 min. Phosphate-buffered saline and hypertonic saline (20%) were used as the negative and positive control groups, respectively. The eosin exclusion test and flame cell motility were employed for the assessment of protoscolex viability. FE-SEM showed the formation of PIP-NCs with a mean size of 279.47 ± 26.61 nm. UV-Vis spectrophotometry and FTIR confirmed the presence of PIP in the NCs. The cytotoxicity assay revealed 92.25 ± 25.61% and 68.45 ± 11.36% viability at concentrations of 1 and 3 mg/mL of PIP-NCs, respectively. Mortality rates of 78.33 ± 0.58, 84.33 ± 0.58, 81.33 ± 1.16, and 87.67 ± 0.58% at 125, 250, 500, and 750 µg/mL of PIP-NCs were recorded after 120 min, respectively. These mortality rates were significantly higher than the negative control group at 120 min (25.67 ± 0.58%) ( p < 0.001). Our results showed preliminary in vitro activity for PIP-NCs against E. granulosus . Combination therapy of PIP-NCs with nanometals or albendazole nanoparticles may reduce required dosages and enhance antiparasitic efficacy. Further studies are warranted to evaluate in vivo applications, safety, potential combination therapies, and molecular mechanisms to optimize treatment outcomes.