Compound L1(Sharda University)

Home to a quarter of the global population, the World Health Organization's South-East Asia Region bears a substantial burden of Neglected Tropical Diseases (NTDs). Identifying means to eliminate NTDs in these regions has been a flagship priority since 2014, with India, Nepal, and Bangladesh committed to eliminating Kala-azar or Visceral Leishmaniasis (VL) sooner or by the end of 2026 (WHO, 2023a). In this context, vanillin-derived molecules are well established in inhibiting several kinases present in cancer cells and have high LD₅₀ values along with broad therapeutic window. In view of the demand of suitable oral candidate for controlling Leishmania parasitic proliferation in human body here, we are reporting ortho vanillin and l-Alanine amino acid derived ligand molecule t2-{(E)-[(2-hydroxy-3-methoxyphenyl) methylidene] amino} propanoate (L) and its Cu(II) conjugates L₁ & L₃ as water-soluble, and nontoxic drug candidates for the treatment of Visceral Leishmaniasis. In silico binding study against potential chemotherapeutic target MAP kinase (Mitogen-Activated Protein Kinase, (PDB id: 4QNY) was undertaken and significant binding was shown by these molecules. Both compounds demonstrated significant inhibition of amastigote proliferation. For L. donovani, L₁ exhibited an IC₅₀ of 1.544 μgml^-1 and L₃ an IC₅₀ of 1.691 μgml^-1. Against L. mexicana, the IC₅₀ values were 1.750 μgml^-1 for L₁ and 1.748 μgml^-1 for L₃. These results were comparable to the standard reference drug Amphotericin B, which exhibited an IC₅₀ of 1.450 μgml^-1 for L. donovani and 1.532 μgml^-1 for L. mexicana. The toxicity studies were undertaken against macrophages THP-1 cell lines where the IC₅₀ value is quite higher in comparison to Amphotericin-B. Additionally, the potential of molecules was checked against PANC-1 cancer cell lines in comparison to normal HPNE cell lines. Both complexes caused double-strand DNA nicks, consistent with the higher cytotoxic activities observed in Cancer cell lines. Furthermore, the cell cycle results also confirmed that L₁ arrested (PANC-1) cells in the G1-S phase of the cell cycle followed by an increase in the sub-G1 phase. L₁, has shown that the population of late/secondary cellular apoptotic cells increased from 2.35 % to 93.56 %, whereas the population of early/primary apoptotic cells increased from 0.13 % (control) to 12.08 %. These findings suggest that L₁ causes apoptosis, or cell death that is programmed.