Inhibitory Effects of Sulfur Derivatives on Leishmania tarentolae Cell Viability and Secreted Acid Phosphatase In Vitro

Sulfonamide drugs were the original class of antibiotics, demonstrating the antibacterial potential of dithiocarbazate and thiosemicarbazone Schiff base derivatives of syringaldehyde and 4-hydroxy-3,5-dimethylbenzaldehyde. We synthesized unique Schiff bases via the condensation of the aldehydes with hydrazine derivatives, which allows for the easy synthesis of several related compounds. These Schiff base derivatives were tested for antileishmanial properties against the parasitic protozoan <i>Leishmania tarentolae</i>. The inhibitory properties of these sulfur compounds were tested using a series of cell viability and secreted acid phosphatase (SAP) assays. The results demonstrated that compounds ZZ1-04 and ZZ1-20 had potent inhibitory effects on parasite cell viability and SAP, an enzyme that may play a role in infectivity. These results increase our understanding of the role of sulfur in inhibiting <i>Leishmania</i>, providing more knowledge of the structural activity relationships that may prove critical for their development into possible antileishmanial treatments.