Montelukast, an approved leukotriene receptor 1 (Cys-LT 1) antagonist with anti-inflammatory properties is used for the treatment of asthma and allergic rhinitis. In the present studies, montelukast was subjected to in vitro inhibitory assays followed by kinetic and in silico investigations. Montelukast demonstrated inhibitory activity against yeast α-glucosidase (IC50 44.31±1.21 µM), jack bean urease (JB urease, IC50 8.72±0.23 µM), human placental alkaline phosphatase (hPAP, IC50 17.53±0.19 µM), bovine intestinal alkaline phosphatase (bIAP, IC50 15.18±0.23 µM) and soyabean 15-lipoxygenase (15-LOX, IC50 2.41±0.13 µM). Kinetic studies against α-glucosidase and urease enzymes revealed its competitive mode of inhibition. Molecular expression analysis of montelukast in breast cancer cell line MCF-7 down-regulated AP by a factor of 0.27 (5 µM) compared with the 0.26 value for standard inhibitor levamisole (10 µM). Molecular docking estimated a binding affinity ranging -8.82 to -15.65 kcal/mol for the enzymes. Docking against the DNA dodecamer (ID: 1BNA) observed -9.13 kcal/mol via minor groove binding. MD simulation suggested stable binding between montelukast and the target proteins predicting strong inhibitory potential of the ligand. Montelukast features a chloroquinoline, phenyl ring, a cyclopropane group, a carboxylic group and a sulfur atom all of which collectively enhance its inhibitory potential against the said enzymes. These in vitro and computational investigations demonstrate that it is possible and suggested that the interactions of montelukast with more than one targets presented herein may be linked with the side effects presented by this drug and necessitate additional work. The results altogether suggest montelukast as an important structural scaffold possessing multitargeted features and warrant further investigations in repurposing beyond its traditional pharmacological use.

Shawana Abdullah is completing her PhD at the age of 29 years from Islamia University of Bahawalpur, Pakistan. She is the visiting lecturer in Islamia University of Bahawalpur, Pakistan. She has 5 Publications which have been cited, many more are in pipeline.