title: Nucleic acid binding properties of allicin: spectroscopic analysis and estimation of anti-tumor potential.
abstract: BACKGROUND
  Allicin has received much attention due to its anti-proliferative activity and not-well elucidated underlying mechanism of action. This work focuses towards determining the cellular toxicity of allicin and understanding its interaction with nucleic acid at molecular level.
  
  
  METHODS
  MTT assay was used to assess the cell viability of A549 lung cancer cells against allicin. Fourier transform infrared (FTIR) and UV-visible spectroscopy were used to study the binding parameters of nucleic acid-allicin interaction.
  
  
  RESULTS
  Allicin inhibits the proliferation of cancer cells in a concentration dependent manner. FTIR spectroscopy exhibited that allicin binds preferentially to minor groove of DNA via thymine base. Analysis of tRNA allicin complex has also revealed that allicin binds primarily through nitrogenous bases. Some amount of external binding with phosphate backbone was also observed for both DNA and RNA. UV visible spectra of both DNA allicin and RNA allicin complexes showed hypochromic shift with an estimated binding constant of 1.2×10(4)M(-1) for DNA and 1.06×10(3)M(-1)for RNA binding. No major transition from the B-form of DNA and A-form of RNA is observed after their interaction with allicin.
  
  
  CONCLUSIONS
  The results demonstrated that allicin treatment inhibited the proliferation of A549 cells in a dose-dependent manner. Biophysical outcomes are suggestive of base binding and helix contraction of nucleic acid structure upon binding with allicin.
  
  
  CONCLUSIONS
  The results describe cytotoxic potential of allicin and its binding properties with cellular nucleic acid, which could be helpful in deciphering the complete mechanism of cell death exerted by allicin.
authors.affiliation: Quantum Optics and Photon Physics, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110 012, India.
authors.forename: Gunjan
authors.initials: G
authors.lastname: Tyagi
authors.forename: Shrikant
authors.initials: S
authors.lastname: Pradhan
authors.forename: Tapasya
authors.initials: T
authors.lastname: Srivastava
authors.forename: Ranjana
authors.initials: R
authors.lastname: Mehrotra
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000378:metabolism*; D004220:Disulfides; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013441:Sulfinic Acids / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D004220:Disulfides; D013441:Sulfinic Acids; C006452:allicin; D004247:DNA; C427203:calf thymus DNA
keywords: Allicin; Deoxyribonucleicacid; Fourier transform infrared spectroscopy; MTT; Ribonucleicacid