Abstract
Background:
Schefflera arboricola L., (S. arboricola L) is a member of the Araliaceae family and exhibits various biological activities. Cryptosporidium parvum, a zoonotic protozoan infection, can infect a variety of vertebrate and invertebrate hosts, including humans.

Aim:
This study aimed to explore the phytochemical constituents and efficacy of S. arboricola leaf extracts against C. parvum infection.

Methods:
The assessment of chlorophyll, carotenoid, carbohydrate, total phenolic, and flavonoid contents in the leaves of S. arboricola was quantified using high-performance liquid chromatography and UPLC/ESI–MS. Parasitological, histological, deoxyribonucleic acid (DNA) fragmentation, liver functions, lipid profiles, and antioxidant parameter analysis will be used to assess the efficacy of the treatments after oral infection with C. parvum oocytes (2 × 103/ mouse). Fifty adult male mice were divided into five groups (10 each): non-treated Cryptosporidium-infected group (G1), infected and treated with low-dose S. arboricola extract (100 mg/kg) (G2), infected and treated with high-dose S. arboricola extract (200 mg/kg) (G3), Nitazoxanide treated (150 mg/kg) (G4), and non-infected group (G5).

Results:
This study quantified the total phenolic and flavonoid contents 267.54 ± 0.61 mg GAE/g and 514.89 ± 0.20 mg rutin/g, respectively, and identified 51 compounds, including 14 phenolic acids and their derivatives, 30 flavonoids, 6 coumarins, and 1 anthocyanin. Both infected-treated mice groups (G2 & G3) showed a considerable improvement in Cryptosporidium oocyte shedding, with significant effectiveness (p < 0.05). In addition, the infected-treated groups showed less severe changes in the intestinal epithelium structures and a significant decrease in DNA fragmentation, hepatic biomarkers, and lipid indices compared with the infected non-treated control group.

Conclusion:
Schefflera arboricola leaves contain a wide variety of pigments, carotenoid, carbohydrate, phenolic, and flavonoid compounds. Extracts of S. arboricola leaves are a new interesting prospective natural product that may be used in the treatment of Cryptosporidium infection.

Key words: Schefflera arboricola L; Phytochemical; Natural product; Anti-Cryptosporidium.