Cytotoxicity evaluation of alternative synthetic and natural antiparasitic compounds in the IPEC-J2 intestinal cell line

Intestinal parasitic diseases represent an important problem, prevalent in developing countries. Increased carrier movement due to globalization, migration, and international travel has contributed to the increase of parasitic diseases in non-endemic regions. Parasitic infections can significantly impair the health condition of people and are particularly dangerous to children and immunocompromised individuals due to their susceptibility to infections (Ahmed M., 2023). The problem of infectious diseases is also accompanied by evidence of increasing environmental pollution caused by the over-consumption of conventional pharmaceuticals. The reasoning behind this is that 100,000 tons of medicinal products are consumed annually by human patients and used for the treatment of animals, and hundreds of active pharmaceutical ingredients are detected in surface water, groundwater, and soil. The growing concern over environmental impacts has led to the development of the concept of “Green Pharmacology”. This concept encompasses all measures that can be applied to reduce or eliminate the usage or formation of toxic substances throughout the life cycle of pharmaceutical products. A promising direction within this framework is the application of natural extracts as alternatives to synthetic drugs. However, despite the advantage of using natural components in replacement of traditional medicine, the evidence base for their efficacy and safety is still limited. Additionally, repurposing existing drugs is considered a promising strategy, although their safety still requires thorough evaluation. The main aim of the present thesis is to investigate the safety of plant extracts and synthetic compounds using an in vitro intestinal model, namely the swine intestinal epithelial cell line IPEC-J2. Natural extracts of Red clover and Tabebuia, along with Clofazimine, NBDHEX, β-lapachone, AN3661, kinase inhibitor 1340, and kinase inhibitor 1717 as alternative molecules, were chosen based on their promising antiparasitic activity. Metronidazole and albendazole, broadly used to treat parasitic infections, were used as control molecules. The cytotoxicity of chosen natural extracts and synthetic compounds was initially evaluated using the Alamar Blue assay. The results indicated that Tabebuia extract exhibited lower cytotoxicity among natural extracts, while the synthetic compound AN3661 displayed the least cytotoxic effect compared to other synthetic compounds. Consequently, these two candidates were selected for additional evaluations, while the remaining compounds demonstrated significant cytotoxic effects and were excluded from further analysis. Subsequently, a lactate dehydrogenase (LDH) release assay was conducted on the selected compounds to confirm the findings from the Alamar Blue assay. Interestingly, while the Alamar Blue results suggested a decrease in cell viability, the LDH release assay revealed no significant membrane damage for either Tabebuia extract or AN3661, highlighting the need for further analysis. The findings of this thesis provide valuable insight into the safety of these alternative therapeutic approaches, contributing to the ongoing exploration of less toxic treatment options for parasitic infections.