College of Education, University of Samarra discussed a Ph.D. thesis on comparing the effect of some secondary metabolites extracted from the lemongrass plant and gold Nano-particles on fat absorption in laboratory rabbits infected with giardiasis by the postgraduate student, Mrs. Marwa Shaker Mahmoud.

The thesis aimed at studying the effect of flavonoids isolated from lemongrass before and after loading them onto gold Nano-particles on the growth of the G.lamblia parasite and the mechanism of fat absorption in rabbits infected with the parasite through isolating one of the secondary metabolic compounds (flavonoids) from the plant, Lemongrass Cymbopogon citratus  and identifying the types of flavonoids by high-performance liquid chromatography, preparing gold Nano-particles and studying their effect in treating giardiasis, the mechanism of fat absorption and the level of oxidative stress, as well as loading the isolated flavonoids on gold Nano-particles and studying its effect in treating giardia and the mechanism of fat absorption and the Oxidative level of stress.

The thesis highlighted that flavonoids isolated from lemongrass are rich in types of flavonoids that have antioxidant and anti-inflammatory activity, such as gallic acid, chlorogenic acid and others, as well as loading the isolated flavonoids onto gold nanoparticles, whose average size was approximately 17 and inducing giardiasis infection using a dose of 4 × 103 bags/cm3, and the incubation period was 4-7 days, the flavonoid extract also showed high effectiveness in treating giardiasis, with a period close to the therapeutic period shown by the drug metronidazole.