Andrographis / Green chiretta

Green chiretta is an annual herb 30–110 cm tall with a square, much-branched stem; leaves are opposite, lanceolate to elliptic, 3–12 cm long, entire and smooth. Small flowers are borne in terminal and axillary panicles, with a white, pink-tinged two-lipped corolla marked with purple; the capsule fruit splits when ripe to release many tiny brown seeds. The whole plant is intensely bitter — so much so that it is popularly called the 'king of bitters'.

The species is native to India and Sri Lanka, regarded as its centre of origin and diversity; from there it spread across South and Southeast Asia (India, China, Thailand, Indonesia, Malaysia, the Philippines, Vietnam and more) and is naturalised in northern India, Java, the Caribbean and the Americas. It grows in many habitats — plains, hillsides, coastlines, farmland, roadsides and disturbed ground — up to about 1,500 m, preferring sun, well-drained soil and a hot, humid climate. In Vietnam it is cultivated and found in many northern and southern provinces.

The characteristic actives are diterpenoid lactones (andrographolides), with andrographolide the most abundant (up to about 4% of dried leaves) and responsible for the bitterness; neoandrographolide, 14-deoxy-11,12-didehydroandrographolide, 14-deoxyandrographolide and dehydroandrographolide also occur. The plant further contains flavonoids (5-hydroxy-7,8-dimethoxyflavone, apigenin-7,4'-dimethyl ether), phenolic acids, tannins and essential oil. Andrographolide is regarded as the marker compound and is the main focus of pharmacological research.

In Indian (Ayurvedic) and Chinese traditional medicine, green chiretta is used to clear heat, detoxify and treat colds, sore throat, pneumonia, dysentery and liver and gallbladder complaints; in Thailand it is famous as Fa-Tha-Lai-Jone. Modern research shows andrographolide is anti-inflammatory (inhibiting NF-κB), antiviral, immunomodulatory, antipyretic, hepatoprotective and anticancer in many models. Systematic reviews and clinical trials report that Andrographis extracts can relieve symptoms of upper respiratory tract infections (colds, sore throat) as well as or better than placebo in some trials — for example KalmCold 200 mg/day reduced cold symptoms more than placebo. Evidence quality remains limited, however, and larger trials are needed.

Green chiretta is generally well tolerated in short-term use; adverse effects are usually mild and include gastrointestinal upset, nausea, headache and fatigue, with rare severe allergy. It should not be used in pregnancy or breastfeeding because of safety concerns, and caution is advised in people with bleeding disorders, low blood pressure, autoimmune disease, or those taking anticoagulants, diuretics, antihypertensives or immunosuppressants. The European Medicines Agency assessed the leaf but could not establish an EU herbal monograph for lack of sufficient data. The species has not been assessed by IUCN (NE); genetic resources remain plentiful through widespread cultivation, but overharvesting in places and habitat loss warrant monitoring.