Usnic acid is a marker compound produced from numerous lichens (symbiotic association of mycobiont and phycobiont) possessing higher bioavailability, potent and selective against cancer cells. Usnic acid is an underutilized and well-documented anti-cancer compound from lichens and its activity is not yet documented against cervical cancer. The main aim of the present research is to screen the anti-cancer potential of usnic acid against cervical cancer target proteins. The drug-likeness validation of usnic acid shows nil violations against all drug-likeness rules when compared with all three screened anti-cancer standard drugs and shows some violation in drug likeness prediction. Further, ADMET screening reveals usnic acids shows effective pharmacokinetic profiles with good bioactivity scores, essential for drug delivery and metabolism. DFT analysis of usnic acid reveals less energy gap (-0.1184), hardness (0.0592 eV), and high softness (16.8918 eV) scores against three anti-cancer drug DFT scores. Molecular docking study shows usnic acid possesses excellent binding affinity with all the nine screened cervical cancer target proteins with docking scores ranging from -6.9 to -9.1 kcal/mol. Three anti-cancer drugs showed docking scores with a range of -5.2 to -8.4 kcal/mol. Further, four top-scored complexes were taken for molecular dynamic simulation study reveal that usnic acid complexes (1KTZ-usnic acid and 2BIM-usnic acid) possess good simulation trajectories with cervical cancer target proteins than the selected anti-cancer drugs.Communicated by Ramaswamy H. Sarma.
Keywords: Cervical cancer; lichens; topotecan; usnic acid.