Abstract
Giardiasis is considered the most common protozoal infection in humans; it frequently occurs in both developing and developed countries. The present study was designed to investigate the therapeutic and prophylactic effects of Punica granatum peel methanolic extract against experimental giardiasis in comparison to metronidazole (MTZ) in mice infected with Giardia intestinalis. There were five experimental groups, as follows: G1; healthy control group, G2; infected untreated, G3; infected treated with MTZ, G4; Infected treated with pomegranate P. granatum, G5; receiving P. granatum for one week before, during induction of infection than continuous administration for another one week. Giardia cyst per gram stool 7 days and 2 weeks after treatment showed a highly statistically significant difference among the different experimental groups (G3,4,5) versus G2, while the percent reduction of mean Giardia cysts/ gm stool 2 weeks after treatment showed a highly significant reduction in G3,4,5 by 92.73, 91.94, and 94.1 %, respectively. The count of Giardia trophozoites in small intestinal content showed a statistically significant difference among G3,4,5 versus G2 respectively with a highly significant reduction in G3,5 and a significant reduction in G4. The percent reduction of mean Giardia trophozoites was approximately 98.69, 58.66, and 95.96 %, respectively. Histopathological examination of small intestines sections of G3 and G4 showed improvement in the pathological lesions including slight restoration of villi/crypt ratio, with partial mucosal ulceration. There was complete healing of intestinal mucosa observable in G5, with a preserved brush border, and no trophozoites were detected. P. granatum peel methanolic extract proved to be valuable in the prevention and treatment of Giardia lamblia infection. Further studies are required to determine the effective therapeutic dose of the extract and its mechanism of action against Giardia lamblia. (c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.