Andrographolide, a diterpenoid lactone isolated from Andrographis paniculata, has traditionally been used in Asian medical systems, particularly Ayurveda and Traditional Chinese Medicine, for respiratory conditions. In recent years, scientific research has explored its effects on the lungs, particularly regarding respiratory tract infections and inflammation. Several randomized controlled trials and meta-analyses have demonstrated that Andrographis extracts, standardized for andrographolide content, can modestly reduce symptoms and duration of acute respiratory tract infections such as the common cold and uncomplicated bronchitis. Proposed mechanisms include anti-inflammatory, immunomodulatory, and antiviral activities, such as inhibition of cytokine production and reduction in airway inflammation.

Preclinical studies in animal models have shown that andrographolide can attenuate lung injury and inflammation in conditions like acute lung injury and asthma, likely by inhibiting NF-κB signaling and reducing pro-inflammatory mediators. However, while laboratory and clinical evidence supports its use for mild, self-limiting respiratory infections, there is limited high-quality evidence for chronic or severe pulmonary diseases. Overall, the use of andrographolide for lung support is justified by both traditional use and a growing body of scientific evidence, but more robust clinical trials are needed to confirm efficacy for specific lung diseases.