A review by Aminian et al. (2022)  finds common basil (Ocimum basilicum) preparations to be effective in symptom relief, and in some cases prevention, of obstructive respiratory disorders.
‘Ocimum basilicum L. (O. basilicum) and its constituents show anti-inflammatory, immunomodulatory, and antioxidant effects. The plant has been mainly utilized in traditional medicine for the treatment of respiratory disorders. In the present article, effects of O. basilicum and its main constituents on respiratory disorders, assessed by experimental and clinical studies, were reviewed. Relevant studies were searched in PubMed, Science Direct, Medline, and Embase databases using relevant keywords including “Ocimum basilicum,” “basilicums,” “linalool,” “respiratory disease,” “asthma,” “obstructive pulmonary disease,” “bronchodilatory,” “bronchitis,” “lung cancer,” and “pulmonary fibrosis,” and other related keywords. The reviewed articles showed both relieving and preventing effects of the plant and its ingredients on obstructive pulmonary diseases such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory disorders such as bronchitis, aspergillosis tuberculosis, and lung cancer. The results of the reviewed articles suggest the therapeutic potential of O. basilicum and its constituent, linalool, on respiratory disorders.’
 Aminian AR, Mohebbati R, Boskabady MH. The Effect of Ocimum basilicum L. and Its Main Ingredients on Respiratory Disorders: An Experimental, Preclinical, and Clinical Review. Front Pharmacol. 2022;12:805391. Published 2022 Jan 3. doi:10.3389/fphar.2021.805391