Herbal preparations traditionally used in upper respiratory tract infections: LC‒MS profile and anti-inflammatory activity in human neutrophils and PBMCs

Upper respiratory tract infections (URTIs) are among the most prevalent illnesses worldwide and are caused by a diverse range of bacterial and viral pathogens. They are characterized by symptoms such as rhinitis, pharyngitis, laryngitis, cough, and fever, which can vary widely in severity and duration. In severe cases, URTIs can progress to lower respiratory tract infections, including bronchitis and pneumonia, or contribute to chronic complications. In light of the limitations associated with conventional therapeutic approaches and the increasing challenge of antibiotic resistance, plant-based treatments have emerged as promising alternative and adjunctive strategies. The diverse and complex phytochemical profile of these plant-based materials exerts a multifaceted influence on the immune system, regulating key cellular mechanisms involved in the initiation, progression, and resolution of inflammation. This study explores the chemical composition and anti-inflammatory properties of ten aqueous and alcoholic extracts derived from medicinal plants that are traditionally employed for the relief of upper respiratory tract infection (URTI) symptoms. The extracts were analysed via liquid chromatography‒mass spectrometry (LC‒MS) and evaluated for their biological activity in immune cell models, specifically peripheral blood mononuclear cells, monocytes/macrophages and neutrophils, which were isolated from human donors. These findings elucidate the mechanisms of action of these natural products, supporting their potential as complementary therapies for early intervention and URTI management.