Antiparasitic effect of pomegranate peel extract-loaded chitosan nanoparticles on Blastocystis spp

Blastocystis species (spp.), cosmopolitan anaerobic protists, are recently associated with inflammatory bowel diseases, and colorectal cancer. Serious side effects, variable efficacy in different subtypes, and rising resistance against the sole drug of choice, metronidazole (MTZ), necessitate a search for safer, effective alternatives. Thus, the present work aims to determine the total phenolic content and the reducing power of pomegranate peel extract (PPE) and testing its efficacy either alone or loaded with chitosan nanoparticles (PPE CSNPs) against Blastocystis spp. in vitro and in vivo compared to MTZ. Anti-Blastocystis activity of PPE and PPE CSNPs were assessed in vitro after 24 h of incubation by estimating parasite count, viability, and ultrastructural morphological changes by scanning electron microscopy (SEM), while assessed in vivo by estimating parasite count, histopathological examination and biochemical study to assess the potential toxicity after 10 days of oral administration to Swiss albino mice. PPE and PPE CSNPs showed significant anti-Blastocystis activity (75.7%, 69.1%) in vitro that were statistically insignificant compared to MTZ in addition to the remarkable ultrastructural distortion showed by SEM. However, MTZ achieved superior effect over PPE and PPE CSNPs in vivo (91.6%, 58.5% and 73.6%, respectively) with moderate tissue repair compared to PPE CSNPs. Significant increase of liver enzymes and creatinine displayed by MTZ (unlike PPE and PPE CSNPs) clarified its detrimental effects on liver and kidney. In conclusion, PPE and PPE CSNPs revealed promising anti-Blastocystis activity with safer effects on the liver and kidney compared to MTZ.