Discipline: Biological Sciences
Aarin M. Huffman - Tuskegee University
Co-Author(s): Daniel A. Abugri, Tuskegee University, Tuskegee,AL
Toxoplasma gondii is an intracellular zoonotic protozoan parasite that causes the disease, toxoplasmosis. Globally, the parasite affects over 2 billion people with mild to severe clinical symptoms in immunocompromised patients (e.g. cancer patients, HIV-AIDS, organ and blood recipients). Current drugs for treatment of T. gondii infection are the antifoliates (pyrimithamine and sulfadiazine). However, these drugs are not effective in eliminating the encysted stage (bradyzoite-slow stage). Not only are these drugs ineffective against the bradyzoite stage of T. gondii, but also have serious adverse side effects against healthy host cells. We hypothesized that curcumin, which is known to have antimicrobial and anticancer activities, will have anti-Toxoplasma gondii activity alone and in combination with quinolone-based drugs against a bradyzoite transforming strain (ME-49 clone 7). In this study, we report the in vitro activity of curcumin, 8-hydroxyquinoline, 4-hydroxyquinazoline, and hydroquinine alone and in combination against T. gondii ME-49 clone 7 strain that is known to affect AIDS patients using Vero cells as media of propagation. Individually, curcumin, 8-hydroxyquinoline, 4-hydroxyquinazoline, and hydroquinine inhibited parasites of approximately 42% at 0.0027 µM; 62% at 0.0269 µM; 57% at 6.84µM; and 49% at 0.192µM, respectively within 48 hours. Additionally, its combination potentiated the anti-Toxoplasma gondii activity of 8-hydroxyquinoline, 4-hydroxyquinazoline, and hydroquinine in vitro. The percent inhibition of the combination of curcumin with 8-hydroxyquinoline, 4-hydroxyquinazoline, and hyrdoquinine were up to 74% at 0.150 µM; 69% at 9.56 µM; and 62% at 5.78 µM respectively. The concentrations that were effective in inhibiting 50% of the parasites growth were not cytotoxic to Vero cells. Overall, the data shows that the ME-49 strain that is known to affect most HIV-AIDS patients could possibly be treated using these combinations. Further studies are underway to screening different strains of T. gondii using these individual and combination formulations in vitro and in vivo. References: Abugri, D. W. (2017, October 30). In vitro antagonistic and indifferent activity of combination of 3-deoxyanthocyanidins against Toxoplasma gonii. Retrieved from NCBI: https://www.ncbi.nlm.nih.gov/pubmed/29086004 Flegr, J. P. (2014, March 24). Toxoplasmosis – A Global Threat. Correlation of Latent Toxoplasmosis with Specific Disease Burden in a Set of 88 . Retrieved from PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0090203 Goo-Kyoung Goo, Y. J.-I. (2015, Dec 23). Characterization of Toxoplasma gondii glyoxalase 1 and evaluation of inhibitory effects of curcumin on the enzyme and parasite cultures. Retrieved from NCBI: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688987/
Funder Acknowledgement(s): The following reagents were obtained through the NIH Biodefense and Emerging Infections Research Resources Repository, NAID, NIH, and BEI Resources: Toxoplasma gondii, ME49 (B7 clone), NR-225, Vero, Kidney (African green monkey), Expressing Luciferase (Luc2p), NR-10385. We also acknowledge the RCMI core Lab facilities that were established with grant number G12MD00785-23 in association with Tuskegee University.
Faculty Advisor: Daniel A. Abugri, firstname.lastname@example.org
Role: The research that I performed was the culturing and seeding of vero cells, seeding of ME49 Clone 7 T. gondii parasites, calculating concentrations of each drug compound used and performing serial dilutions on them, pipetting of drug compounds, measuring parasite inhibition and growth using the BioTek Power Wave XS microplate reader, determining the IC50 on Graph Pad Prism, and forming the data onto an excel spreadsheet.