Molecular docking analysis of phytoconstituents from Nilavaagai Chooranam with histamine H1 receptor

<i>Nilavaagai Chooranam</i>, a polyherbal formulation in Siddha medicine, is traditionally used for treating respiratory and allergic conditions. Histamine H1 receptors are central to allergic reactions and modulating their activity can help manage conditions like allergic rhinitis and asthma. The objective of this study is to investigate the potential of bioactive compounds in <i>Nilavaagai Chooranam</i> to modulate histamine-mediated allergic responses by targeting the histamine H1 receptor. Molecular docking analysis was conducted to evaluate the binding affinities of key phytochemicals Kaempferol, Gingerenone-A, Piperic acid, Embelin, Carvone, and β-pinene against the H1 receptor (PDB ID: 3RZE). Cetirizine, a well-known H1 antagonist, was used as a reference ligand. Significant interactions were observed between the phytochemicals and the H1 receptor. Gingerenone-A and Embelin exhibited the highest binding affinities, with interactions involving key residues like Trp428, Tyr431, and Phe432. These results were comparable to those of Cetirizine. Data shows that <i>Nilavaagai Chooranam</i> contains compounds with anti-allergic and anti-inflammatory potential, supporting its traditional use in treating histamine-mediated conditions. Further <i>in vitro</i> and <i>in vivo</i> studies are needed to validate these <i>in silico</i> results and explore the formulation's potential as a natural alternative to synthetic antihistamines.