Andrographolide

Andrographolide is a labdane diterpene lactone and the principal bioactive constituent of the plant Andrographis paniculata, commonly used in traditional medicines. Its chemical formula is C20H34O5, and it appears as a pale crystalline solid with relatively low water solubility.

Andrographis paniculata, also known as kalmegh or the king of bitters, is native to South and Southeast Asia. Andrographolide makes up a major portion of extracts from the plant, which also contain related diterpenoids such as neoandrographolide. Commercial preparations often standardize extracts to a specified andrographolide content.

In preclinical studies, andrographolide has demonstrated anti-inflammatory, immunomodulatory, antiviral, hepatoprotective, and, in some models, anticancer activity. Proposed mechanisms include inhibition of the NF-kB signaling pathway, downregulation of pro-inflammatory cytokines (such as TNF-α and IL-6), suppression of COX-2 and iNOS, and antioxidant effects. The pharmacokinetic profile indicates limited oral bioavailability with rapid metabolism and clearance in many studies.

Clinical evidence in humans is limited and results are mixed. Some trials have suggested modest benefits for upper respiratory tract infections, but the quality and consistency of evidence vary. Safety concerns include gastrointestinal upset and, rarely, hepatotoxicity, particularly with prolonged high-dose use. Use during pregnancy or lactation is generally cautioned, and potential interactions with other medications via hepatic enzymes should be considered under medical supervision.

Regulatory status varies by jurisdiction. Andrographolide is not approved as a pharmaceutical drug in major markets; it is mainly used as a component of herbal supplements and traditional remedies. Products may differ in quality and standardization, influencing safety and efficacy.