An ex vivo study of the efficacy of auranofin against Cryptosporidium parvum

Background: Cryptosporidiosis, a zoonotic infection, could be fatal in immunosuppressed patients. Nitazoxanide (NTZ) has unsatisfactory results in immunosuppressed individuals, necessitating the search for a safe and more effective alternative. Auranofin (AUR), an FDA-approved treatment for rheumatoid arthritis, showed potent anti-inflammatory and anti-protozoal effects. Objective: Evaluation of the ex vivo effects of AUR on Cryptosporidium parvum in comparison with NTZ. Material and Methods: The study was done using 6-well culture plates, which were divided into 5 groups of ileal explants: Uninfected, infected untreated, infected treated with NTZ, Infected treated with AUR, and Infected treated with both drugs. The drugs were added six hours PI. After 24 hours of the drug treatment, the explants from all groups were collected and processed for histopathological and ultrastructural assessments, and the culture supernatants were collected for immunological and biochemical assessments. Results: Histopathological and ultrastructural evaluation of ileal tissues showed marked restoration of the normal intestinal structure in the combined treated group, followed by the AUR group, while the NTZ group showed only partial improvement with persistent pathological changes in enterocytes and marked ultrastructural abnormalities. Both NTZ and AUR showed significant reduction in IFN-γ and IL-1β levels and a significant increase in IL-10 levels, suggesting their anti-inflammatory effect. NTZ induced an elevation in TrxR levels in intestinal tissue with no significant difference compared to the infected control group. However, the lowest level of TrxR enzyme was reported in the AUR group. Conclusion: AUR achieved superior results regarding anti-cryptosporidial and anti-inflammatory activities with oxidant effects on the parasite compared to NTZ. The combination group showed the best results. Thus, AUR could be a promising anti-cryptosporidial drug with synergistic effects of AUR-NTZ combined therapy. Therefore, further in vivo and human studies on the anti-cryptosporidial effects of AUR are recommended.