In‐vitroantileishmanial potential of peptide drug hirudin

Abstract

Hirudin is clinically an important drug used for the treatment of cardiac diseases, but has never been elucidated for antileishmanial potential. This study was designed to determine the therapeutic utility of hirudin against leishmaniasis. Binding affinities of 28 potent proteinase inhibitors were screened computationally against leishmanolysin (GP63), out of which hirudin exhibited higher binding affinity with GP63 and good expected IC values. Experimentally, hirudin showed most promising activity against promastigote and axenic amastigote forms of leishmanial parasites with IC values of 0.60 ± 0.36 μg/mL and 0.43 ± 0.23 μg/mL, respectively, in a dose- and time-dependent assay. The cytotoxicity assay revealed no adverse effects on human macrophages with LD value of 860.11 ± 53.44 μg/mL. Hirudin caused leishmanial cell death mainly by apoptosis and membrane permeability. In spite of the basic knowledge obtained, hirudin mechanism is considerably less prone to the induction of resistance than classical drugs. Collectively, this study fosters further studies for the hirudin as new antileishmania lead with a new mode of action.

Benzoic Acid Derivatives of Ifloga spicata (Forssk.) Sch.Bip. as Potential Anti-Leishmanial against Leishmania tropica

“…For compound 2, one hydrogen bond was formed with the benzene ring and Ala348 residue, and pi-alkyl interactions were also observed for the carbonyl oxygen and methyl group (-CH 2 ) with Ser449 and Ala349 residues, respectively. The molecular-level interactions that showed binding with the gp63 involved major hydrophobic protein residues, thus, a drug with more lipophilic groups could more easily bind to gp63 and effectively inhibit its activity [38] (Figure 4). SYTOX green assay was carried out to check membrane damage, and visualization under the fluorescence microscope confirmed that both compounds were responsible for damaging the cell membrane of Leishmania.…”

“…Acridine orange assays are used to characterize different stages of apoptosis in cells and to check for DNA damage. Acridine orange dye can insert into DNA and emits green fluorescence when bound to normal DNA or dsDNA, and red fluorescence when bound to damaged or ssDNA [38]. For both compounds, early apoptotic (EA) cells started appearing at 12 h and increased along with the treatment time, whereas late apoptotic (LA) cells were observed after 48 h of treatment.…”

“…Cells were suspended, washed with Hank's buffer salt solution (HBSS) three times, and were resuspended in HBSS along with 1 mM SYTOX Green stain. The plate was kept in the dark for 10-15 min, and a fluorescent microscope was used to check the membrane permeability [38].…”

Atividade biológica de complexos organometálicos carbenos N-heterocíclicos de Au(I) em "Leishmania" sp.

“…No caso do tempo de 16 h, foram observados resultados de inibição muito próximos daqueles observados para 24 h. principais moléculas de superfície em promastigotas de Leishmania. 94 Interessantemente, a GP63 é uma metaloprotease Zn-dependente com importante papel na virulência parasitária que poderia ser alvo dos compostos de Au I , já que possuem alta afinidade pelo sítio de ligação do zinco.…”