The therapeutic effects of Plantago major and its main constituents on respiratory diseases: a narrative review.

Herbal medicines have been proposed as adjuvant treatment for respiratory diseases. One such agent is Plantago major (P. major). Therefore, this review aims to gather the most recent experimental and clinical evidence on P. major's therapeutic effects on respiratory diseases. This review search was performed through Web of Science, PubMed, Google Scholar, and Scopus from the 1990s to March 2024. In experimental studies, the effects of P. major on inflammation, infection, asthma, and COPD models were established. In clinical studies, a significant reduction in cough and wheezing, increases in FEV1 and FVC in asthmatic patients, a rapid effect on signs and symptoms of bronchitis, and antiviral effects were observed. Despite in vitro and animal studies, there are limited clinical studies on the respiratory effects of P. major on humans. Therefore, designing more clinical studies to identify the respiratory effects of the plant and its derivatives should be considered.