Annona muricata Leaf as an Anti-Cryptosporidial Agent: An In Silico Molecular Docking Analysis and In Vivo Studies.

Cryptosporidiosis is a serious parasitic diarrheal disease linked to the occurrence of colorectal cancer in immunocompromised patients. The FDA-approved drug nitazoxanide (NTZ) achieved a temporary effect, and relapses occur. Annona muricata leaf is widely used in traditional medicine to treat a wide range of disorders, including antiparasitic and anticancer effects. So, this study aimed to investigate Annona muricata leaf antiparasitic and anticancer properties compared to NTZ in Cryptosporidium parvum ( C. parvum ) acutely and chronically infected immunosuppressed mice. A molecular docking analysis was performed to evaluate the effectiveness of some biologically active compounds that represented the pharmacological properties of Annona muricata leaf-rich extract toward C. parvum lactate dehydrogenase compared to NTZ. For the in vivo study, eighty immunosuppressed albino mice were classified into four groups as follows: group I: infected and treated with A. muricata ; group II: infected and treated with nitazoxanide; group III: infected and received no treatment; and group IV: were neither infected nor treated. Furthermore, half of the mice in groups I and II received the drugs on the 10th day post-infection (dpi), and the other half received treatment on the 90th day post-infection. Parasitological, histopathological, and immunohistochemical evaluations were performed. The docking analysis showed that the lowest estimated free energy of binding of annonacin, casuarine, L-epigallocatechin, P-coumaric acid, and ellagic acid toward C. parvum LDH, were -6.11, -6.32, -7.51, -7.81, and -9.64 kcal/mol, respectively, while NTZ was -7.03 kcal/mol. Parasitological examination displayed a significantly high difference in C. parvum oocyst mean counts in groups I and II compared to group III ( p -value < 0.001), with group I demonstrating the highest efficacy. The analyses of histopathological and immunohistochemical results revealed that group I showed restoration of the normal villous pattern without evidence of dysplasia or malignancy. A. muricata leaf has proved to be a reliable agent for Cryptosporidium treatment. This paper argues for its promising use as an antiparasitic agent and for the prevention of neoplastic sequels of Cryptosporidium infection.