Calotropis gigantea

Calotropis gigantea, the crown flower, is a species of Calotropis native to Cambodia, Vietnam, Bangladesh, Indonesia, Malaysia, Thailand, Sri Lanka, India, China, Pakistan, and Nepal.

It is a large shrub growing to 4 m (13 ft) tall. It has clusters of waxy flowers that are either white or lavender in colour. Each flower consists of five pointed petals and a small "crown" rising from the center which holds the stamens. The aestivation found in calotropis is valvate i.e. sepals or petals in a whorl just touch one another at the margin, without overlapping. The plant has oval, light green leaves and milky stem. The latex of Calotropis gigantea contains cardiac glycosides, fatty acids, and calcium oxalate. The roots also contain Calotropone.

In Ayurveda, used the root and leaf in asthma and also used in bacterial infection, swelling with redness, boils also and shortness of breath and the bark in liver and spleen diseases. The plant is reported as effective in treating skin, digestive, respiratory, circulatory and neurological disorders and was used to treat fevers, elephantiasis, nausea, vomiting, and diarrhea. The milky juice of Calotropis procera was used against arthritis, cancer, and as an antidote for snake bite. However, these reports are of folk uses and more research is needed to confirm the clinical usefulness of the leaves, latex, and bark. Recent studies have displayed use of calotropin as a contraceptive and as a promising cancer medication. In one study of the cancer-fighting properties of Calotropis gigantea, DCM extracts were demonstrated to be strongly cytotoxic against non-small cell lung carcinoma (A549), colon carcinoma (HCT 116), and hepatocellular carcinoma (Hep G2). These extracts show promise as cancer medications and warrant further clinical research.

Calotropis gigantea is part of the catalog of ayurvedic medicinal plants of Sri Lanka.