Antiparasitic Activity of Hedera helix Extract-Loaded Chitosan Nanoparticles in Experimentally Induced Giardiasis

Giardiasis, caused by <i>Giardia duodenalis</i>, is a common gastrointestinal infection. This study aimed to evaluate the effects of <i>Hedera helix</i> leaf extract (HLE) and HLE-loaded chitosan nanoparticles (HLE-CsNPs) against <i>Giardia duodenalis</i> isolates from individuals with gastrointestinal issues, using an experimental rat model. Stool samples from 147 participants were analyzed for <i>Giardia duodenalis</i>, with positive samples further characterized by nested PCR-RFLP, revealing a 4.8% prevalence, all belonging to assemblage B. Ten groups of male albino rats were used to evaluate the antigiardial activity of various treatments. This included five non-infected groups [one untreated and four treated with HLE, HLE-CsNPs, CsNPs, and metronidazole (MTZ)] and five infected groups [one untreated and four similarly treated]. Treatment efficacy was assessed using parasite counts, intestinal histopathology, CD117 immunohistochemistry, and markers of liver and kidney function. HLE-CsNPs markedly reduced <i>Giardia</i> cysts by 88.8%, approaching the 99.2% reduction achieved by MTZ, while also improving intestinal architecture and reducing inflammation. Importantly, HLE and HLE-CsNPs provided superior protection for the liver and kidneys compared to MTZ. In conclusion, HLE-CsNPs exhibited significant antigiardial activity and organ protection in rats, suggesting a potential alternative treatment for <i>Giardia duodenalis</i> isolated from individuals with gastrointestinal issues.