Category: Medicines - plant based
Introduction and description
Smilax is a genus of about 300–350 species, found in the tropics and subtropics worldwide. In China for example about 80 are found (39 of which are endemic), while there are 20 in North America north of Mexico. Some of the species are used to make foods and beverages of which the most famous is probably Sarsaparilla.
An extract from the roots of some species is used to make the sarsaparilla drink and other root beers, as well as herbal drinks like the popular Baba Roots from Jamaica. Two species, S. domingensis and S. havanensis, are used in a traditional soda-like Cuban beverage called pru.
The roots may also be used in soups or stews. The young shoots can be eaten raw or cooked and are said to taste like asparagus, and the berries can be eaten both raw and cooked. Stuffed smilax pancake, or fúlíng jiābǐng (simplified Chinese: 茯苓夹饼; traditional Chinese: 茯苓夾餅), is a traditional snack from the Beijing region. Due to the nectar-rich flowers, species like S. medica and S. officinalis are also useful honey plants.
All of which is very fortuitous because this plant has shown to have extensive medicinal uses.
In the USA,the genus is divided into a number of sections.
- · Section Smilax includes "woody", prickly vines of temperate North America, for example catbriers and greenbriers (S. glauca) and common greenbrier (S. rotundifolia). Greenbriers get their scientific name from the Greek myth of Crocus and the nymph Smilax. Though this myth has numerous forms, it always centres around the unfulfilled and tragic love of a mortal man who is turned into a flower, and a woodland nymph who is transformed into a brambly vine
- · Section Nemexia includes unarmed herbaceous plants of temperate North America, for example "carrion flowers" like the smooth herbaceous greenbrier (S. herbacea).
Smilax are climbing flowering plants, many of which are woody and/or thorny, in the monocotyledon family Smilacaceae, native throughout the tropical and subtropical regions of the world.
On their own, Smilax plants will grow as shrubs, forming dense impenetrable thickets. They will also grow over trees and other plants up to 10 m high, their hooked thorns allowing them to hang onto and scramble over branches. The genus includes both deciduous and evergreen species. The leaves are heart shaped and vary from 4–30 cm long in different species.
Greenbrier is dioecious. However, only about one in three colonies have plants of both sexes. Plants flower in May and June with white/green clustered flowers. If pollination occurs, the plant will produce a bright red to blue-black spherical berry fruit about 5–10 mm in diameter that matures in the autumn.
The berry is rubbery in texture and has a large, spherical seed in the centre. The fruit stays intact through winter, when birds and other animals eat them to survive. The seeds are passed unharmed in the animal's droppings.
Cultivation and habitat
Smilax is a very damage-tolerant plant capable of growing back from its rhizomes after being cut down or burned down by fire. This, coupled with the fact that birds and other small animals spread the seeds over large areas, makes the plants very hard to get rid of. It grows best in moist woodlands with a soil pH between 5 and 6. The seeds have the greatest chance of germinating after being exposed to a freeze.
Besides their berries providing an important food for birds and other animals during the winter, greenbrier plants also provide shelter for many other animals. The thorny thickets can effectively protect small animals from larger predators who cannot enter the prickly tangle. Deer and other herbivorous mammals will eat the foliage, as will some invertebrates such as Lepidoptera (butterflies and moths), which also often drink nectar from the flowers.
S. glabra is used extensively in Chinese herbology. It is also a key ingredient in the Chinese medical dessert guīlínggāo, which makes use of its property to set certain kinds of jelly.
The powdered roots of some species are used as a traditional medicine for gout in Latin American countries. It is being investigated for numerous forms of cancer. And has been used as an anti-inflammatory in the treatment of rheumatoid arthritis.
The plants are used extensively to combat allergies and allergic reactions. Recent research has shown that a combination of effects of various phytochemicals is responsible for the anti-allergic activity of Smilax herbal preparations. The plants are highly complex in their chemical constituents and it is all the constituents acting synergistically that account for the strong observed anti-allergic in vitro activity.
Köhler's Medicinal Plants of 1887 discusses the American sarsaparilla (S. aristolochiifolia), but as early as about 1569, in his treatise devoted to syphilis, the Persian scholar Imad al-Din Mahmud ibn Mas‘ud Shirazi gave a detailed evaluation of the medical properties of chinaroot.
Traditional Chinese medicine has dealt with lues venerea (syphilis) since the Five Dynasties period (10th century). Many Europeans studied Chinese indigenous materia medica and then integrated them into local treatments. Jean Astruc published an ethnopharmacological survey carried out in Beijing in the 1730s in a medical treatise De Morbis venereis… ('On venereal diseases…') published in 1740. Astruc identified about 34 medicinal plants used in treating syphilis amongst which were Sassafras tzumu, Smilax china, and S. glabra.
The anti-bacterial properties of Smilax species seem to mediate many of the effects and cures attributed to the plants, recent research has concentrated on a number of STDs, not just syphilis and varieties of Smilax have been found to be effective against candidiasis for example [see observations for details].
Of the phenolic compounds in Smilax plants, quercetin and rutin have been found to work together producing strong antioxidant activity. The antifungal activity of the plants includes that against Candida albicans, Candida glabrata, Candida krusei, Candida parapsilosis, Candida tropicalis and Cryptococcus gattii.
References and further reading
- Kew World Checklist of Selected Plant Families
- Flora of China Vol. 24 Page 96, 菝葜属 ba qia shu, Smilax Linnaeus, Sp. Pl. 2: 1028. 1753.
- Flora of North America Vol. 26 Page 468, Catbrier, greenbrier, sarsaparilla, Smilax Linnaeus, Sp. Pl. 2: 1028. 1753; Gen. Pl. ed. 5, 455. 1754.
- Allspice and the menopause 006911
- Chemical constituents from the rhizomes of Smilax glabra and their antimicrobial activity. 027420
- Immunomodulatory activity of the aqueous extract from rhizome of Smilax glabra in the later phase of adjuvant-induced arthritis in rats. 027419
- Mitochondrial apoptosis contributes to the anti-cancer effect of Smilax glabra Roxb. 027421
- Suppressive effect of modified Simiaowan on experimental gouty arthritis - an in vivo and in vitro study 027418