Comparative Molecular Docking Analysis of Ocimum sanctum Compounds and Anti-Allergic Drugs Against Allergic Rhinitis Targets

Allergic rhinitis, commonly referred to as hay fever, is a hypersensitivity reaction caused by exposure to small airborne allergens such as pollen, dust, or animal dander. It is one of the most prevalent allergic disorders worldwide and in the United Kingdom affects nearly one-fifth of the general population. The condition has been closely linked with asthma and allergic conjunctivitis, forming part of a broader spectrum of atopic diseases. Clinically, allergic rhinitis manifests with characteristic symptoms including persistent sneezing, nasal congestion, rhinorrhea, coughing, postnasal drip, and headaches, which can significantly impair quality of life and productivity if left untreated. In recent years, there has been growing interest in exploring natural therapeutic agents as alternatives or complements to conventional antihistaminic drugs. In our study, bioactive compounds from Ocimum sanctum (commonly known as holy basil) were assessed in comparison to selected anti-allergic drug molecules for their capacity to inhibit key biochemical targets associated with allergic inflammatory pathways. Specifically, molecular docking analyses were performed against the crystal structure of human DPP4 in complex with the chitotriosidase-1 (hCHIT) catalytic domain bound to compound 7g (PDB ID: 5NRA). Among the standards tested, Levocetirizine, a widely prescribed second-generation antihistamine, achieved a docking score of –7.2 kcal/mol. Notably, Isoaromadendrene epoxide, a phytoconstituent isolated from the methanolic extract of O. sanctum, demonstrated superior binding affinity with a docking score of –8.2 kcal/mol. These encouraging findings highlight the potential of Isoaromadendrene epoxide as a natural therapeutic lead in allergic rhinitis management. Nevertheless, comprehensive pharmacological investigations, including mechanistic studies, dose optimization, and clinical validation, remain essential before translating these outcomes into practical medical applications.