Mutamba is a medium tree growing to 20 meters in height with a trunk 30 to 60 cm in diameter. It is indigenous to tropical America on both continents and found in the Amazon Rainforest. Its oblong leaves are 6-12 cm in length and the tree produces small white to light yellowish flowers. It produces an edible fruit that is covered with rough barbs.

Mutamba has had a place in herbal medicine in almost every country where it grows. The bark and the leaves are most used medicinally however sometimes the fresh root is employed. In Belize, a small handful of chopped bark is boiled for 10 minutes in 3 cups of water and drunk for dysentery and diarrhea, prostate problems and as a uterine stimulant to aid in childbirth.⁽¹⁾ A slightly stronger tea is used externally for skin sores, infections and rashes.⁽¹⁾ In Brazil, a bark tea is considered diaphoretic and used for fevers, coughs, bronchitis, asthma, pneumonia and liver problems.⁽²⁾ Mutamba is called Guasima or Guacima in Mexico where it has a very long history of indigenous use. The Huastec Mayans of northeastern Mexico employed the fresh bark boiled in water for a childbirth aid, gastrointestinal pain, asthma, diarrhea and dysentery, wounds and fevers.⁽³⁾ In Peru, the dried bark as well as the dried leaves are boiled into tea and used for kidney disease, liver disease, and dysentery.⁽⁴⁾ In other parts of Peru and the Amazon Mutamba is used internally and externally for alopecia, asthma, bronchitis, dermatosis, diarrhea, dysentery, elephantiasis, fever, hepatitis, leprosy, malaria, nephritis, pulmonosis, and syphilis.⁽⁵⁾ In Guatemala the dried leaves of the tree are brewed into a tea and drunk for fevers, kidney disease, and skin diseases as well as used externally for wounds, sores, bruises, dermatitis, skin irruptions and irritations, and erysipelas.^{(6, 7)}

With a long history of effective uses in herbal medicine, researchers began studying Mutamba's properties and activities in the laboratory beginning in 1968 and it has been the subject of numerous studies since. In the first study published, vaious water and alchohol Mutamba bark extracts demonstrated weak cardiac depressant and cardiotonic activity, as well as hypotensive, smooth muscle relaxant, and uterine stimulant activities in animal studies.⁽⁸⁾ Various leaf and bark extracts have clinically demonstrated in vitro antibacterial and antifungal activity against numerous pathogens in 5 different studies from 1987 to 1993.^{(7, 9-12 )} It also tested to have active properties against gonorrhea in vitro in a 1995 study.⁽¹³⁾ A weak molluscicidal activity of the bark was documented in a 1974 study.⁽¹⁴⁾

Of particular note, a Brazilian research group demonstrated that a dried leaf extract was cytotoxic against cancer cells in vitro, giving a 97.3% inhibition of cell growth in a 1990 study.⁽¹⁵⁾ Some of the latest research on Mutamba has focused on the antioxidants found in the bark and leaves (proanthocyanidins) and their ability to interfere with prostaglandin synthetase, a process by which bacteria and pathogens replicate.^(16-18)

10 "Guazuma ulmifolia Lam. Sterculiaceae. "Bolaina", "Atadijo", "West Indian elm". Wood and bark for construction and ropes. Ripe fruits have a strong honey scent. Some people even chew the fruit to extract the sweet juice, spitting out the remainder. The macerated fruit mixed with aguardiente is used to scent the "siricaipe" or "mapacho". In Jamaica the bark is used to feed silkworms. Leaf decoction used for baldness, the bark decoction for dysentery (SOU). Elsewhere regarded as astringent, depurative, diaphoretic, emollient, pectoral, refrigerant, stomachic, styptic, and sudorific; used for alopecia, asthma, bronchitis, dermatosis, diarrhea, dysentery, elephantiasis, fever, hepatitis, leprosy, malaria, nephritis, pulmonosis, and syphilis (DAW, RAR).

By James A. Duke: GUAZUMA ULMIFOLIA Lam. West Indian elm (E); Bastard cedar (J); Cabeza de Negrito (P); Guacimo (C,P) . The green fruits of this honey tree are edible fresh or cooked, and are relished by cattle. They are crushed in water to make a beverage, and to add flavor to meats. The leaves and fruits are eaten by cattle and deer. The bark is used for cordage, and is regarded as sudorific. It is used to treat elephantiasis, cutaneous diseases, and chest afflictions. The sap is used to clarify syrup in sugar-making, and was used for food and shaving cream in Colombia. In Darien, the uncooked bark is soaked with malva to drink for afflictions of the kidney and liver (!). In the Pearl Islands, people believe that touching the tree will slow bleeding (!).