''Dioscorea composita'', or barbasco, is a species of yam in the family '' Dioscoreaceae''. It is native to

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. It is notable for its role in the production of diosgenin, which is a precursor for the synthesis of

hormone A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...

s such as

progesterone Progesterone (; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...

Russell Marker Russell Earl Marker (March 12, 1902 – March 3, 1995) was an American chemist who invented the octane rating system when he was working at the Ethyl Corporation. Later in his career, he went on to found a steroid industry in Mexico when he s ...

developed the extraction and manufacture of hormones from ''D. mexicana'' at

Syntex Laboratorios Syntex SA (later Syntex Laboratories, Inc.) was a pharmaceutical company formed in Mexico City in January 1944 by Russell Marker, Emeric Somlo, and Federico Lehmann to manufacture therapeutic steroids from the Mexican yams called ''c ...

, starting the trade of ''D. composita'' in Mexico. Marker also discovered that the ''composita'' variety had a much higher content of diosgenin than the ''mexicana'' variety, and therefore it came to replace the latter in the production of synthetic hormones.

Chemical constituents

Steroidal sapogenin, diosgenin.

Medicinal use

It is a source of diosgenin, which is used to prepare synthetic

hormones A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physiology and behavior. Hormones a ...

such as

and

cortisone Cortisone is a pregnene (21-carbon) steroid hormone. It is a naturally-occurring corticosteroid metabolite that is also used as a pharmaceutical prodrug. Cortisol is converted by the action of the enzyme corticosteroid 11-beta-dehydrogenase ...

. Diosgenin extracted from ''Dioscorea composita'' was instrumental in the development of the

combined oral contraceptive pill The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be Oral administration, taken orally by women. It is the oral form of combi ...

in the 1960s – and also for the development of cortisone treatments of

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

. Studies on Diosgenin say that it has effect on

diabetic neuropathy Diabetic neuropathy includes various types of nerve damage associated with diabetes mellitus. The most common form, diabetic peripheral neuropathy, affects 30% of all diabetic patients. Studies suggests that cutaneous nerve branches, such as the s ...

. Before becoming used industrially the tuber was used by Chinantec healers in northern

Oaxaca Oaxaca, officially the Free and Sovereign State of Oaxaca, is one of the 32 states that compose the political divisions of Mexico, Federative Entities of the Mexico, United Mexican States. It is divided into municipalities of Oaxaca, 570 munici ...

as an

abortifacient An abortifacient ("that which will cause a miscarriage" from Latin: '' abortus'' "miscarriage" and '' faciens'' "making") is a substance that induces abortion. This is a nonspecific term which may refer to any number of substances or medications, ...

and in cures for aching joints. It was also used by chinantecs as a poison for fishing in the

Papaloapan river The Papaloapan River () is one of the main rivers of the Political divisions of Mexico, Mexican state of Veracruz (state), Veracruz. Its name comes from the Nahuatl ''papaloapan'' meaning "river of the Butterfly, butterflies". In 1518 Juan de Grij ...

, and is also mentioned in use for this purpose in the

Popol Vuh ''Popol Vuh'' (also ''Popul Vuh'' or ''Pop Vuj'') is a text recounting the mythology and history of the Kʼicheʼ people of Guatemala, one of the Maya peoples who also inhabit the Mexican states of Chiapas, Campeche, Yucatan and Quintana Roo, ...

, the sacred book of the K'iche maya.

References

{{DEFAULTSORT:Dioscorea composita composita Yams (vegetable) Taxa named by William Hemsley (botanist)