Andrographis paniculata: a critical appraisal of extraction, isolation and quantification of andrographolide and other active constituents.

Andrographispaniculata, referred to as 'Kalmegh' in ancient texts, is regarded as a nostrum of the modern world. Oral administration of the leaves of this plant is effective in the treatment of upper respiratory tract infections, liver toxicity and a variety of other ailments. The practices of adulteration in the original material of this drug have made it imperative to develop techniques to verify the authenticity of the products of this plant for quality assurance. Andrographolide, a bitter diterpenoid, is the major active principle present in the plant, and therefore its determination and quantification in the plant extracts are important. This article provides a detailed account of various extraction and chromatographic techniques used for the identification, isolation and quantification of the various active principles of A. paniculata. Pharmacological properties and phytochemistry of this plant and the physico-chemical properties of these bio-compounds have also been outlined.