Background: Giardiasis treatment is a challenge as traditional medical treatment exhibits drug resistance
with multiple side effects. Hence ongoing trials for exploring anti-giardiasis alternatives are being achieved
utilizing chitosan nanoparticles (CsNPs) and medicinal plants.
Objective: To investigate the therapeutic efficacy of Moringa oleifera leaves extract (MOE) and M. oleifera
extract-loaded CsNPs (MOE-Cs NPS) against experimental giardiasis compared to Metronidazole (MTZ).
Material and Methods: Eighty male Swiss albino mice were divided into two equal groups: group A (noninfected),
and group B (infected). Each group was divided into four subgroups. While mice of subgroups
A1, and B1 represent negative and positive giardiasis controls; those of A2, A3, A4, and B2, B3, B4 were
treated with MOE, MOE-CsNPs, MTZ, respectively. Treatments began on the 3rd day post infection (dpi)
and lasted for seven days, and scarification was done three days after the end of treatments. Evaluation
parameters included stool cyst load, histopathological intestinal changes, and cyst ultrastructural changes
by scanning electron microscopy (SEM). Hepatic and renal toxicity were biochemically assessed.
Results: The marked improvement in cyst shedding was recorded in subgroup B3. Giardia cyst reduction
rate was (86.01%) with significant efficacy (P≤0.001) compared to B2 and B4 subgroups (76.89% and
79.76%) respectively. Results of SEM demonstrated that the MOE-CsNPs-treated group had the most
noticeable cyst disfigurement alterations, with no harmful effects on hepato-renal functions.
Conclusion: Combined MOE and CsNPs therapy is a novel potential natural product for reducing the
number of Giardia cysts shedding in stool and improving the pathological changes in treating giardiasis.