Andrographolide, a major bioactive component of Andrographis paniculata, has been traditionally used in Asian medicine for its anti-inflammatory and antimicrobial properties. In recent decades, scientific studies have explored its potential as an alternative or adjunct to antibiotics. Laboratory research shows that andrographolide possesses notable antibacterial activity against several bacterial strains, including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The mechanisms proposed include inhibition of bacterial biofilm formation, modulation of immune responses, and disruption of bacterial cell wall synthesis.

Several in vitro and animal studies support its antibacterial effects, though human clinical trials directly evaluating andrographolide as an alternative to antibiotics are limited. Some randomized controlled trials with Andrographis paniculata extracts have shown efficacy in treating upper respiratory tract infections, suggesting possible antimicrobial and symptom-relieving benefits. However, these studies often focus on the whole plant extract rather than isolated andrographolide, and the effects may be due to a combination of anti-inflammatory and immunomodulatory actions rather than direct antibacterial activity.

In summary, there is moderate scientific evidence (rating 3/5) supporting andrographolide’s antibacterial properties in preclinical models, and some indirect clinical evidence for Andrographis extracts in mild infections, particularly as a supportive therapy. However, robust clinical trials specifically substituting antibiotics with andrographolide are lacking, so its use as a primary antibiotic alternative remains preliminary.