Andrographis paniculata

Distribution

It is distributed in tropical Asian countries, often in isolated patches. It can be found in a variety of habitats, such as plains, hillsides, coastlines, and disturbed and cultivated areas such as roadsides, farms, and wastelands. Native populations of A. paniculata are spread throughout south India and Sri Lanka which perhaps represent the center of origin and diversity of the species. The herb is an introduced species in northern parts of India, Java, Malaysia, Indonesia, the West Indies, and elsewhere in the Americas. The species also occurs in the Philippines, Hong Kong, Thailand, Brunei, Singapore, and other parts of Asia where it may or may not be native. The plant is cultivated in many areas, as well.

Unlike other species of the genus, A. paniculata is of common occurrence in most places in India, including the plains and hilly areas up to 500 m (1,600 ft), which accounts for its wide use.

In India the major source of plant is procured from wild habitat.The plant is in Low Risk or Least Concerned in the IUCN category. Under the trade name Kalmegh Annually on an average 2,000–5,000 tonnes (2,200–5,500 tons) of plant is traded in India.^[4]

Cultivation

It does best in a sunny location. The seeds are sown during May and June (northern hemisphere). The seedlings are transplanted at a distance of 60 cm (24 in) x 30 cm (12 in).

Alternative medicine

A. paniculata has been used in Siddha and Ayurvedic medicine,^[5] and is promoted as a dietary supplement for cancer prevention and cure. The Memorial Sloan-Kettering Cancer Center has stated that there is no evidence that it helps prevent or cure cancer.^[6] Other uses of A. paniculata are linked to its antibacterial and antioxidant properties, largely derived from the one of the active phytochemicals andrographolide.^[7] Research shows andrographolide is also anti-inflammatory and modifies the toll-like receptor (TLR) TRIF-dependent pathway which is part of the body's innate immune response to bacterial and viral infection, and it also suppresses NF-κB activation and COX-2 molecules as further illustration of its anti-inflammatory potential.^[8]

There is a growth in interest in A. paniculata as it might provide a safe and effective alternative to the prescription of antibiotics, as antimicrobial resistance from the over-prescription of these drugs is a major threat to global public health.^[9] In a systematic review that identified and analysed 33 randomised controlled trials of 7175 patients with upper respiratory tract infections, the use of the herb Andrographis reduced the severity of cold and flu symptoms compared to a placebo (4 studies) and was more effective than the patients normal care regimen in other studies (12 studies). Out of 7175 patients identified in this review, there were 7 individual cases of adverse events including constipation or headache, although it must be noted many trials do not report these events at all.^[10] In a study of patients with mild to moderate ulcerative colitis, andrographis extract was as effective and offered a safer treatment option for patients after eight weeks of use compared to standard medication.^[11]

Treatment of patients with rheumatoid arthritis with the active component andrographolide (28 patients) compared to a placebo (30 patients) for 14 weeks saw no significant difference in overall measures of pain intensity (by VAPS, visual analogue pain scale), but there were improvements in the grading of the tenderness of joints and reductions in other biological measures including rheumatoid factor and immunoglobulin A. The authors concluded that A. paniculata could be a "natural complement" for the treatment of rheumatoid arthritis but a larger study of longer duration would be a logical next step.^[12]

Chemistry

Andrographolide is the major constituent extracted from the leaves of the plant and is a bicyclic diterpenoid lactone. This bitter principle was isolated in pure form by Gorter (1911). Systematic studies on chemistry of A. paniculata have been carried out.^[13][14]

Some known constituents are:

• "14-Deoxy-11-dehydroandrographolide, Plant
• 14-Deoxy-11-oxoandrographolide, ahhiajajaiop.Plant
• 5-Hydroxy-7,8,2',3'-Tetramethoxyflavone, Plant
• 5-Hydroxy-7,8,2'-Trimethoxyflavone, Tissue Culture
• Andrographine, Root
• Andrographolide, Plant
• Neoandrographolide, Plant
• Panicoline, Root
• Paniculide-A, Plant
• Paniculide-B, Plant
• Paniculide-C, Plant"^[15]