The Asclepiadaceae form a climax family specializing in staminal corona, a gynostemium and pollinia. The family contains more of herbs and shrubs rather than trees and consists of 2000 species included in 250 genera. The members are laticiferous herbs, vines or shrubs. Trees are rare. A group of plants like Caralluma have become modified to cactus-like succulents. The compounds manufactured include cardiac glycosides,alkaloids of indole, pyridine and Phenanthro indolizidine groups and proanthocyanins.
Divided to 2 subfamilies.
1. Periplocoideae are primitive in that the stamens are free, corona mostly corolline and anthers are connate around the stigma, but not fused with stigma. The gynostegium and pollinia are absent here.
2. The second subfamily, the major one, is the Asclepiadoideae containing all the plants with gynostegium, pollinia and staminal corona.
A. Medicinal plants
1. Asclepias curassavica Linn (Gk Asklepios = god of medicine, due to the
medicinal properties of this plant -Kakatundi, Blood flower)
This is an erect much-branched perennial, a native of Tropical America, now cultivated as an ornamental plant. The leaves of Brazilian plants yield cardenolides such as clepogenin,
curassavogenin, ascurogenin, carotoxigenin, uzarigenin, coroglaucigenin and a glycoside uzarin. But the leaves from Indian plants are devoid of the first four compounds but are found of
contain 22 cardenolides of which calactin, calotropin, calotropagenin and asclepin are the major compounds. The Mexican samples yielded a cytotoxic compound, calotropain also. The roots are found to contain vincentoxin (asclepiadin).All parts of the plant are used in medicine. Root is considered emetic, cathartic, astringent and a remedy for gonorrhoea and piles. Roots are used
as substitute of ipecac. The whole plant is used as emetic, styptic and purgative and the extract is found to inhibit carcinomatous cells of human nasopharynx. The plant, as powder, balm or
enema, is used to destroy abdominal tumours. The latex is used against warts and corns.
2. Calotropis gigantea Ait.f. (Arkah, Milkweed)
An erect tomentose laticiferous shrub, this is a very common weed occurring in the dry regions of India. The root bark, which constitutes the drug, yields cardiac glycosides such as gigantin, giganteol, isogiganteol, calotroposides A-G, steroids like α- and β-amyrins, taraxasterol and its derivatives, β-sitosterol and a wax. The latex, found in all parts of the plant, contains caoutchouc (rubber), resin, cardiac glycosides gigantin, calotropin, uscharin, calotoxin,
calactin and uscharin (all based on the genin calotropagenin), proteases like calotropain, calotropin D1 and D2 , calotropain F1 and F2 and enzymes like invertase. Leaves contain free
sapogenins, β-amyrin, β-sitosterol, taraxasterol, ψ-taraxasterol, tannins and resin. Root bark is a substitute for ipecac and in small doses it acts as a diaphoretic and expectorant. It is useful in
leprosy and eczema. A 50% ethanolic extract is found to be anticancerous and low doses of crude methanolic extract is hypertensive and cardiotonic. Latex is a drastic purgative and emetic and induces abortion. The fibre is used for ropes, clothes and as a filling fibre. The whole plant is used as an insecticide (against white ants and larvae of Culex and Anopheles), fish poison and possesses both antifungal and antibacterial properties.
In Indian systems of medicine the tender fresh leaves are used to cure fits and convulsions in children and for migraine.
3. Calotropis procera Ait.f.(Alkarka, Dead Sea Apple)
The root bark, which constitutes the drug, contains α- and β- amyrins, taraxasterol and its isomers,isovalerates and acetates, giganteol, β-sitosterol and a wax. The latex, present in all the parts,
consists of caoutchouc, resin and cardiac glycosides, proteases and steroids. The cardiac glycosides are calotropin, uscharin, calotoxin, calactin, uscharidin (all based on the genin calotropagenin), voruscharin, proceroside and two genins, uzarigenin and syriogenin. The proteases encountered are calotropain F1, F2, calotropin D1 and D2. C. procera is found to possess almost all medicinal properties of C. gigantea and used likewise.
4. Gymnema sylvestre R.Br. (Madhunashi, Gymnema).
G. sylvestre is a large, much-branched woody twiner, a native of tropical Africa.The leaves contain gymnemic acids (with gymnemic acid being the main component), 3-beta-glucuronides of acylated gymnemagenins (hexa hydroxy olean-12-one), gymnestrogenin and conduritol A. The leaves and stems are hypoglycemic and
therefore used in treating diabetes. They are diuretic and stimulate cardiovascular system. The drug is useful in skeletal fractures and exerts a purgative action.
Gymnemic acid can destroy the ability to taste sweet substances.
5 Hemidesmus indicus R.Br. (Periploca indica Linn. Anantamool/ Sariva, Indian Sarsaparilla)
This is a twining undershrub with a woody rootstock, a native of India. Roots, which are used as the drug, contains an essential oil consisting of p-methoxy salicylic aldehyde; coumarinolignoids hemidesminine (C23H22O8) and hemidesmin 1& 2 and steroids such as hemidesmol, hemidosterol, lupeol octacosanate
and beta-amyrin acetate and coumarin. Stem contains pregnane glycosides hemidine, hemidescine, emidine, indicine, a triterpene lactone (3-keto-lup-12-ene 21(28)-olide), besides 12 dehydrolupeol acetate, lupeol acetate, sitosterol and several hydroxy methoxy benzaldehydes. Sariva is one of the rejuvenating drugs and is cooling and blood purifying. It is an alterative, aphrodisiac,
refrigerant, diuretic and tonic. It is also useful in chronic rheumatism, anaemia, dyspepsia, leucorrhoea, uterine haemorrhage and skin diseases. It is also used in abdominal tumours and an antilithic.
6. Leptadenia reticulata W & A. (Jivanti, Leptadenia)
Jivanti is a laticiferous shrubby twiner common in Western Ghats and N.E.Asia. Stems and roots yield wax consisting of long-chain alcohols (C28-C34) and acids (C28-C34), sterols such as stigmasterol, -sitosterol and a fructosan of 7-8 units. Roots are considered a rasayana (tonic) drug, useful for vitalizing the body. It is an aphrodisiac, rejuvenative, galactogogue and cures weakness, cough, dysentery, night-blindedness and tuberculosis. Leaves
are useful in skin diseases.
7. Pergularia daemia Choiv. (Daemia extensa R.Br. Pergularia extensa N.E.Br. Kurutakah, Pergularia)
This is a perennial twiner with milky latex, found all over India, S.E.Asia and Africa. Stem and seeds contain cardenolides such as calactin, calotropin, calotropagenin (from seeds) uzarigenin, coroglaucigenin (from stems). The plant is used for vesical calculus, dysurea and anurea. Leaf juice is emetic and expectorant and used in asthma, rheumatism, menstrual disorders and diarrhoea. Leaves are used externally for rheumatic swellings.
8. Tylophora indica Merrill. (T. asthmatica W.& A.- Dumvel, Tylophora)
T. indica is a woody twiner native to India. The whole extract of leaves and roots possess powerful vescicant properties. All the parts of plant possess alkaloids. Out of the numerous
compounds known, only three are important i.e. tylophorine, tylocebrine and tylophorinine. The whole extract of the leaves and roots possess powerful vescicant properties a property attributed
to tylophorine and so used effectively in fighting asthma. Tylophorine has a paralyzing action on the heart muscle, but a stimulating action on the muscles of blood vessels. All the three
principal alkaloids possess anticancer properties.
C. Biopesticides
1. Calotropis gigantea Ait.f
Arkah is used as an insecticide by many a rural folk in Gujarat.
2. C. procera Ait.f
The larvae of Anopheles stephensi List., Aedes aegypti Linn and Culex fatigans Wiedm died within three hours of putting in 50,000 ppm latex water. It is also an effective fish poison.
Aqueous extract of leaves inhibited the larval hatching of the root knot nematode Meloidogyne incognita. The alkaloidal fraction of leaves serves as an antifeedant to desert-locust (Schistocerca gregaria). A decoction of leaves, along with soap, is an effective remedy against aphids and white ants. Leaf powder is used to control the pulse beetle Callosobruchus chinensis Linn, a serious pest of stored cowpeas. Flower tops showed antifeedant activity against Rhyzoptera dominica Fabr., a pest of stored grains.
3. Cryptostegia grandiflora R.Br.
This is a lofty laticiferous climber with large glossy elliptic leaves, long large rose-colored showy flowers and 3-winged follicles. A native of Tropical Africa, this plant is extensively cultivated in gardens. Aerial parts contain proteolytic enzymes (in latex) cardenolides such as oleanodrigenin, rhodexin B, 16-propyonyl- and 16-anhydrogitoxy genin and gitoxygenin. The leaves exhibit molluscicidal activity.
4. Cynanchum arnottianum Wt.
This native of E. Asia is a perennial climber. The whole plant, especially leaves, are insecticidal useful to kill maggots in the wounds of animals.
5. Sarcostemma acidum Voigt. (Somlatha)
This is a leafless East Indian succulent wine, (leaves reduced to minute scales), flowers in umbellate cymes and thick follicles. It is also used as an insecticide.
D. Biofuels
1. Cryptostegia grandiflora R. Br.
The biocrude obtained from the plant on hydrocracking yield gases, naphtha, kerosene and gas oil along with coke and residue rich in hydrocarbons (65%). Some of the main constituents of gases are methane, n-heptane, ethane and n-octane. The naphtha contains alkanes and naphthenes and can be used for production of benzene, toluene, xylene or high octane gasoline pool. (Anon, 2001). Hexane is the preferred solvent for biocrude extraction. The
biocrude can be used as a chemical feed stock.
A. General uses
1. Cryptostegia grandiflora R. Br. and C. madagascariensis Miq. are woody lianas which yield the Palay rubber.
Reference
Mammen Daniel
