Soap Nuts

Sapindus is a genus of about five to twelve species of shrubs and small trees in the soapberry family, Sapindaceae, native to warm temperate to tropical regions in both the Old World and New World. The genus includes both deciduous and evergreen species. Common names include soapberry and soapnut, both names referring to the use of the crushed seeds to make soap.

Category: File - :Sapindus emarginatus in Hyderabad W IMG_4650.jpg|thumb|left|Sapindus emarginatus leaves in Hyderabad, India.

The leaves are alternate, long, pinnate, with 14-30 leaflets, the terminal leaflet often absent. The flowers form in large panicles, each flower small, creamy white. The fruit, called a soap nut, is a small leathery-skinned drupe diameter, yellow ripening blackish, containing one to three seeds.

Soap nuts contain saponins, a natural surfactant. They have been used for washing for thousands of year by various peoples, such as the Native Americans. Today, soapberries are being considered for commercial use in cosmetics and detergents, among many other products.

Soap nuts have historically been used in folk remedies as an expectorant

, emetic, contraceptive, and for treatment of excessive salivation, epilepsy, and to treat chlorosis. The effectiveness of some of these folk-remedy treatments have not been subject to extensive scientific scrutiny. However, modern scientific medical research has investigated the use of soap nuts in treating migraines

. Investigation of the contraceptive capability of plant saponins have shown some spermicidal capacity for certain extracts.B.S. Setty, V.P. Kamboj and N.M. Khanna, Screening of Indian Plants for biological activity Part. VII. Spermicidal activity of Indian plants. Indian J Exp Biol 15 (1977), pp. 231?232.S. Garg, G. Doncel, S. Chabra, S.N. Upadhyay and G.P. Talwar, Synergistic spermicidal activity of neem seed extract, reetha saponins and quinine hydrochloride. Contraception 50 (1994), pp. 185?190. While the Sapindus saponins cause less irritation, they are less potent bactericidal agents than modern chemical alternatives. The medical implications of these findings are not clear.

Category: File - :Sapindus emarginatus in Hyderabad W2 IMG_4648.jpg|thumb|left|Sapindus emarginatus soap nut in Hyderabad, India.

Soap nuts are among the list of herbs and minerals in Ayurveda. They are a popular ingredient in Ayurvedic shampoos and cleansers. They are used in Ayurvedic medicine as a treatment for eczema, psoriasis, and for removing freckles. Soap nuts have gentle insecticidal properties and are traditionally used for removing lice from the scalp.

Soap nuts are antimicrobial and are beneficial for septic systems and greywater. Soap nuts are used in the remediation of contaminated soil. They are used by jewelers, especially in India and Indonesia, to remove the tarnish from silver and other precious metals.

Sapindus species are used as food plants by the larvae of some Lepidoptera (moths and butterflies) species including Endoclita malabaricus.

;Species

The number of species is disputed between different authors, particularly in North America where between one and three species are accepted.

*Sapindus delavayi (China, India)

*Sapindus detergens (syn. var. Soapnut, Ritha)

*Sapindus drummondii (syn. S. saponaria var. drummondii) Western Soapberry (southwestern United States, Mexico)

*Sapindus emarginatus Vahl Southern Asia

*Sapindus marginatus Florida Soapberry (Florida to South Carolina); included in S. saponaria by some authors.

*Sapindus mukorossi India (Himalayas)

*Sapindus mukorossi Gaertn. Chinese Soapberry (Southern China west to the Himalayas)

*Sapindus oahuensis Hillebr. ex Radlk. Lonomea (Hawaii endemic)

*Sapindus rarak DC. (Southeast Asia)

*Sapindus saponaria L. Wingleaf Soapberry (southeastern United States, Caribbean, island of Hawaii, Central and South America)

*Sapindus tomentosus (China)

*Sapindus trifoliatus L. South India Soapnut or Three-leaf Soapberry (Southern India, Pakistan)

*Sapindus vitiensis A.Gray (American Samoa, Samoa, Fiji)

Category: Image - :Western Soapberry.jpg|thumb|Western Soapberry berries