Cullen corylifolium

Cullen corylifolium, synonym Psoralea corylifolia, (babchi) is a plant used in Indian and Chinese traditional medicine. The seeds of this plant contain a variety of coumarins, including psoralen.

Etymology
Corylifolium comes from similarity of the leaves to those of Corylus, a genus of tree in northern world regions, such as Sweden.

Description
Cullen corylifolium grows 50–90 cm tall and is an annual plant. It has pale-purple flowers in short, condensed, axillary spikes. Its corolla is pale purple. Flowers one-seeded fruits. The most distinctive feature is the occurrence of minute brown glands which are immersed in surface tissue on all parts of the plant, giving it a distinctive and pleasant fragrance.

Habitat and distribution
Cullen corylifolium is native to north-east tropical Africa, the southern Arabian Peninsula, and tropical and subtropical Asia, including India and Sri Lanka. It was occasionally cultivated in Arabia for its supposed medicinal properties.

Chemical constituents
Cullen corylifolium extract contains numerous phytochemicals, including flavonoids (neobavaisoflavone, isobavachalcone, bavachalcone, bavachinin, bavachin, corylin, corylifol, corylifolin and 6-prenylnaringenin), coumarins (psoralidin, psoralen, isopsoralen and angelicin), meroterpenes (bakuchiol, and 3-hydroxybakuchiol).

Use in traditional medicine
Cullen corylifolium, or bu gu zhi in traditional Chinese medicine, is an herb used as a therapy for several disorders, such as treatment of lichen planus by psoralen extract combined with sunlight exposure.