In the worship of Adonis, it was customary to grow gardens of representative plants of cultural and food value as part of maintaining the cycle of fertility of the culture. This custom comes from a time-immemorial practice of the gatherers and after them the founding agricultural centres, of collecting and guarding the stock of all plants of cultural, food or medicinal value to preserve the well-being of society.
The number of medicinally and even industrially important plants has grown ever larger and indicates the undiscovered potential still awaiting us in ever increasing fragility as the environmental assault continues. These two articles and their additions give a brief perspective on these two areas.
1: The Chemical Complexity of Food.
The Herbs of Medical Science
"THE DISTINGUISHED PHARMACOGNOSIST Norman R. Farnsworth, indicates that in 1980 a quarter of the prescriptions dispensed from community pharmacies in the United States contained active principles from the higher plants - these chemicals numbering about 100. The survey does not include medications used at hospitals, or prescriptions including the so-called wonder drugs. Penicillin, streptomycin, and the others usually are fungal extracts. Though part of the Plant World, fungi are not considered part of the Plant Kingdom proper-rather a separate domain. These 100 most important medicines from green plants are derived from only 41 species, with several of the alkaloid-producing plants contributing more than one compound. Opium poppies contain a number of useful alkaloids including morphine, codeine, and papaverine" (Ayensu et. al. 184).
"The genus Strychnos produces the medically useful compounds strychnine and the curare of arrow-poison fame - without which modern surgery would not be possible. The heart and other organs are relaxed with curare, while life is sustained through the use of machines. From the mandrake (Mandragora officinarum) comes scopolamine, the "truth serum" of World War 11 espionage fame, now a standard pre-operative medication. The heart stimulant digitalis comes from a wild foxglove of Europe, and steroids from wild yams provide precursors, or raw materials, for hydrocortisone and birth control pills" (Ayensu et. al. 184).
The Medicinal discovery of Curare: Gill convinced several brujos to show him how they prepared the poison. This was done with great ceremony, for the making of curare was the work of a specialist and not to be done without the proper deference to tradition. - Five days to gather materials. Over the first day, almost twenty kilos of stems from three types of vine, tonispa pala ango, lamas ango, and tonispa were bruised with stones, passed three times around the brujo's head as a nod to the spirits, and boiled in water until it was a black syrup, at which point foam "like a black-brown egg white which has been beaten" formed at the surface. By comparing the ingredients used by several brujos, Gill narrowed down the sources of curare's potency. Mayanchi and two other brujos he watched had only one plant in common in their recipes: tonispa pala ango. It was a woody vine, a climber that could grow as thick as a man's thigh and wind for dozens of meters through the trees. Gill collected many specimens of it. It was not Strychnos, that much he knew. In fact, it would later be identified at the New York Botanical Garden as Chondodendron (sometimes spelled Chondrodendron and first associated with curare by the explorer Guillermo Klug). It was a genus of the moonseed family, Menispermaceae, a tropical species described by eighteenth-century botanist Antoine L. Jussieu. Indeed, one brujo, Felipe Aguinda, told Gill that he could make curare using only tonispa palo ango. Gill got hold of one such batch of curare and tested it on a guinea pig. Given a dose of .15 cc injected into the hind leg, a guinea pig weighing half a kilo was paralyzed in just over one minute, and dead in two. This, indeed, was the real thing (Earthly Goods Joyce 43).
Diosgenin from wild yams (see
heading illustration) provides a precursor to steriod hormones,
as does the poroporo plant from New Zealand (Bruneton 546).
"One of the earliest plant drugs to be synthesized was aspirin, in 1899, in which a substance from willow bark provided a chemical blueprint for the synthesis. Aspirin, a "wonder drug" in its own right, was followed during World War II by penicillin, first of the antibiotics, an extract from a common fungal mold. Since then, literally dozens of healing substances extracted from molds of the soil and from other sources have been cultured in vast quantities in special nutrient solutions. The knowledge of culture mediums and their industrial exploitation represents one of the great advances in medical and nutritional technology. Vitamin C ascorbic acid, once came primarily from lemons, black currants, acerola, roses, and other green plants. Today, microscopic fungi grown in vats provide most of our ascorbic acid. A recent wonder drug, Cyclosporin A, was first cultured from a soil sample gathered in Madison, Wisconsin, by an employee of a Swiss pharmaceutical company. The effect of the experimental extract was strong, but this particular organism could not be cultured in bulk. Colypocladium inflatum, a more adaptable species, could. It turned up in a Norwegian fjord. The drug suppresses rejection of newly implanted organs. Liver transplants have become far safer due to the drug, which may also help fight malaria. The well is indeed not dry. Norman Farnsworth notes that of five thousand species of flowering plants tested, a thousand contained alkaloids of potential importance. This leaves the majority of species in the Plant World - hundreds of thousands - to be investigated" (Ayensu et. al. 184).
Taxol (Bruneton 516)
Taxol: (Scientific American June 1996)
Hazel nuts are also being touted as an extractable source of taxol as Yew trees become scarce.
The poisonous nature of the Yew tree was known to Julius Caesar, and the Pacific Yew Taxus brevifolia was used as a disinfectant, aborteficant and cure for skin cancer by Native Americans. In the 1960s it was discovered that an extract of the bark killed artificially-preserved leukemia cells. But it was only in 1978 that it was discovered, after it proved effective against advanced ovarian tumors that it killed cancer cells in a completely new way - by making the cell's microtubules rigid killing it during cell division. This also causes side-effects by killing other rapidly dividing cells as is common with cemotherapeutic agents. Taxol a diterpene spindle poison has been discovered to be effective in treatment of intractible ovarian cancer, however the first species used, Taxus brevifolia had such low concentrations in the bark, that the projected medicinal requirements would have destroyed the entire species within ten years. Subsequently it was found in the leaves of T. brevis, providing a renewable source. In a process which was described as conquering a molecular mount everest, a semi-synthesis using precursors in the leaves and then a complete synthesis of taxol was discovered.
"The quest for plants with important medicinal effects leads to every part of the globe. Eleutherococcus senticosus, a Manchurian plant in the ginseng family with no history of use in traditional medicine, was classified and named in 1859. It attracted so little notice that for a century-until Russian researchers screened a number of Far Eastern plants for medicinal activity-the only common name for it was the scientifically incorrect "Siberian ginseng." Today Soviet citizens routinely use extracts of this plant, although Western doctors are largely unfamiliar with it. According to Stephen Fulder of Chelsea College of London University, the E. senticosus compound is restorative rather than curative. Like other substances highly valued in Eurasia and the Far East, where the prevailing systems of medicine emphasize prevention of disease, it may improve the general health and energy of people-who are weakened or under stress. Dr. Fulder has coined the term somatensic, keyed to the drug's action in extending human performance. This name literally means "body-expander." The extract is thought to improve the endurance, the reflexes, and concentration of Soviet athletes. Preparations are also used by Russians in physically active occupations, especially by divers, rescuers, climbers, explorers, soldiers, factory workers, truck drivers, and aviators. Cosmonauts in the Salyut 6 /Soyuz 32 space station employed it" (Ayensu et. al. 189).
"Doctors in Soviet hospitals and clinics prescribe doses of the plant extract along with other medicines for disorders such as anemia, depression, chronic heart disease, pneumonia, and tuberculosis. Soviet doctors also consider it useful for problems of convalescence and old age. The case of E. senticosus demonstrates that there are plant drugs used by other cultures that would repay careful study with a view to their possible introduction elscwhere. An outstanding source of research materials is the People's Republic of China where a billion people depend on traditional medicine most of which involves plant drugs. As Norman Farnsworth says: "Can such a medical system have survived for 3,000 years if the entire populace was being served placebo medication?" (Ayensu et. al. 189).
"The same applies to the Hindu system of Ayurvedic medicine in which about fifteen hundred of the drugs used are derived from plants. Some of modern medicine's most important plants actually face local extinction. These include the crisped glory lily (Gloriosa superba), a climbing plant with elongated tubers and beautiful flowers with curved, wavy petals. Their hues vary from cool green to yellow to hot orange-red and they grow in greatest numbers in the coastal areas of India's states of Gujarat, Maharashtra, and Karnataka. The plump roots have been used in the treatment of parasitic skin infections, leprosy, and internal worms, and are valuable in Ayurvedic Medicine, a regional herbalism of long history and considerable renown. The lily's underground, tuber-like rhizomes contain alkaloids, including colchicine-best known for suppressing gout but now tested for anti-cancer properties. Investigators have determined that the seeds rather than the rhizomes are the most economical source of the drug. Glory lily flowers are so beautiful that masses of them are collected for sale in bouquets, destroying prospects of seed development. It is believed that most of the medicinal material is exported, and collection of seeds and roots for the foreign market causes a shortage of raw material for local drug industries in India. If wild populations of Indian medicinal plants are allowed to become damaged through excessive collection, a whole series of traditional medicines which have been in use for thousands of years - the Ayurvedic, Unani, Greco-Urvedic, and Indo-Tibetan schools of herbal medicine - will be threatened. Indians are also active in modern biomedical research into the chemical properties of unfamiliar plants. One mint among these species, a close relative of the house plant Coleus blumei, is an hypotensive. A member of the hog-plum family may combat cancer. The old systems of Indian medicine lost official acceptance during the early 1900s as the European system, derived from the canon of the Greek herbalists Hippocrates and Dioscorides, began to supplant earlier doctrines. The uses of a number of plants were thus buried under subsequent "modern" training, and are only now being brought to light and tested. One of these is Gymnema sylvestre, a woody climber of the milk-weed family from southern India which had been used in the treatment of "honey-urine" for two thousand years. This disease is the familiar diabetes mellitus, which was first identified by the famous Indian surgeon Sushrutha, who detected sugar in the urine of diabetic victims in the sixth century B.C. Studies of the hypoglycemic action of dried, powdered leaves of Gymnema in diabetes mellitus are now being undertaken at the University of Madras. Given the undesirable side effects that insulin and synthetic hypoglycemic oral drugs can have in diabetic therapy, this research is of great potential importance. In men, impotence sometimes accompanies diabetes" (Ayensu et. al. 190).
"A new way to study this impairment employs the alkaloid yohimbine, derived from the bark of the African yohimbe tree (Corvanthe yohimbe) in the coffee family. It is reputed to be an aphrodisiac. In a study at Queen's University in Ontario, Canada, some impotent patients who received daily doses of synthesized yohimbine achieved erection and orgasm. The Madagascar periwinkle (Catharanthus roseus), a common ground cover, has become a major source of chemicals-most notably vinblastine and vincristine-for the treatment of childhood leukemia and Hodgkin's disease. The therapeutic effect of Catharanthus (formerly Vinca) roseus is mainly derived from alkaloids in its leaves and stems. Their discovery and development represents a remarkable medical breakthrough" (Ayensu et. al. 190).
Anti-cancer properties of Food Plants
Many food plants have significant anti-cancer properties associated with both vitamins and other biodynamic principles. These may be pivotal in maintaining longlevity in humans who come from a diverse gatherier-hunter origin.
"The patient was a 49-year-old machinist. For nine months he had suffered from generalized Hodgkin's disease ... When he came to Lilly's Clinical Research Laboratories, he carried a ten-inch tumor in his chest ... on March 2, 1960, he received his first injection of - Lilly's new anticancer product, Velban. Within four days his pain had disappeared. In a week he was walking. Afier 12 davs his tumor began to shrink ... in four (months), the tumor was gone" (Ayensu et. al. 186).
"These words come from a copy of a 1961 'Lilly Review', house newspaper for Eli Lilly and Company, and seem almost too miraculous to be true. But so was an announcement in 1983 that for the first time in history the cure rate for cancer had risen above fifty percent in the United States. The statistic is quite true, as is the above quote. Until recently, though, those who knew best about the effect of the chemicals vinblastine and vincristine were cancer patients who could be treated either at the doctor's office or in a hospital for a short period each month. At other times the person undergoing chemotherapy could resume a near-normal life as treatment progressed. The chemicals behind the cures began as alkaloids manufactured naturally within a small flowering plant, Catharanthus roseus. Commonly known as the rosy periwinkle or Madagascar periwinkle, the flower has been widely introduced beyond its original island. Velban, the Lilly trade name for vinblastine, derives from an abundant compound within the plant's leaves. Another cancer drug from the same plant, Oncovin, begins as a very scarce alkaloid called xrincristine. Fortunately, due to a process developed in Hungary, the more abundant vinblastine can be transformed in the laboratory to vincristine. The discovery of both of these active substances, now produced commercially by Lilly, can be traced to a large-scale effort of the United States National Cancer Institute in the 1950s to screen plants for anti-cancer properties. Industry help was enlisted. Scientists at Eli Lilly were intrigued bv folklore from Africa and elsewhere which associated the rosy periwinkle with treatment of diabetes: scientists separated more than eighty alkaloids from periwinkle leaves but found no medicine for the disease. Vinblastine, however, reduced the white cell content of the blood. Runaway production of white blood cells is one characteristic of leukemia. Indeed, without vincristine therapy, there would be no cures of childhood leukemia. Also, in combination with other medicines, vinblastine therapy achieves a cure rate of 80 percent in cancer of the testicle, formerly fatal in most cases. The periwinkle alkaloids apparently prevent cell division in animals and man. The wild growth of tumor cells and the unchecked division of white blood cells are reduced through chemotherapy. Fortunately, chemicals from the periwinkle work in concert with other agents, and even alone often have the power to initiate a remission. Then the other medicines can work more effectively to destroy the original cancerous growth and also stop the spread of cancer cells from the active malignancy. Coupled with strict schedules of injections, called protocols, the various formulas and dosages are especially effective. While cures for cancer are a blessing, further knowledge of plants may aid in prevention of the disease. Recent government announcements in the United States suggest that changes in diet and smoking and drinking habits can reduce chances for the onset of cancer. In years ahead we may well possess the ounce of prevention as well as the pound of cure. Cancer may one day become as rare as polio and smallpox (Ayensu et. al. 186).
"The direct extraction of only one ounce of vincristine requires fifteen tons of periwinkle leaves and costs well over six thousand dollars. Small quantities are so effective, however, that only ten pounds a year are employed in the United States. Eli Lilly markets vincristine by the trade name Oncovin. Vinblastine, known to the trade as Velban, is far more plentiful. Some nations, including the People's Republic of China, are augmenting the natural supply of periwinkle alkaloids by mass growing of the plants. Because of the low yield of vincristine from Catharanthus roseus, the Chinese find it necessary to process up to a quarter of a million pounds of dry leaves at a time in order to recover a reasonable yield of this alkaloid. The leaves represent only about 10 percent of the total dry weight of the plant, so the Chinese usually harvest nearly two million pounds of fresh plants at a time. Vinca minor, the common periwinkle, has been grown for centuries in gardens. It yields an alkaloid known as vincamine, one currently under clinical investigation in France and elsewhere. The drug may help to delay senility by increasing the supply of oxygen to brain cells. In addition to the periwinkles, the dogbane family (Apocynaceae) has given us the valuable snakeroot plant (Rauwolfia serpentine). A shrub native to India, snakeroot has been used here medically since 2000 B.C. The root itself yields more than 75 alkaloids, including reserpine - first isolated in the 1950s. Important in sedatives and tranquilizers, reserpine is also used in the treatment of such mental derangements as paranoia and schizophrenia. It also effectivelv alleviates hypertension and complications of high blood pressure and strokes, heart disease, and kidney failure. Because laboratory synthesis of reserpine costs $1.25 per gram, plant material is more commonly used for commercial preparation, at the cost of approximately 75 cents per gram of the purified alkaloid. Due to reliance on natural sources for the commercial supply, this plant became threatened by overcollecting. To conserve it the government of India has placed an embargo on the export of the roots. In some instances, market demand can threaten the survival of these species in the wild. Yet as with the periwinkle in China, propagation of medicinal plants in the developing world can reduce the erosion of genetic resources and create business opportunities. There is currently an enormous surge of interest in the use, development, and conservation of medicinal plants throughout the world. Several official bodies are involved, including the World Health Organization (WHO) whose effort to integrate modern and traditional medicine in the developing world is outlined in the next chapter. The United Nations Industrial Development Organization seeks the establishment of local pharmaceutical industries based on wild plants, and the OECD is planning a major program on the economic value of medicinal plants. Traditional medicine also has its enthusiasts in the industrial nations, where herbal teas are so popular that some of their plant sources are locally endangered."
Plant that cheers
A FOLK remedy for depression may really help to drive away the blues. Doctors in Germany often prescribe extracts of St John's wort (Hypericum perforatum) for anxiety, depression and sleep disorders. German and American researchers have now reviewed 23 previous trials of the plant involving 1757 patients and report their findings in the current issue of the British Medical Journal. Depressed patients given extracts of St John's wort were 2.67 times as likely to improve as those given a placebo. That makes St John's wort as effective as standard antidepressants, but with fewer side effects. Eventually, St John's wort could move from the apothecary's garden to the clinic. "This research is raising a lot of eyebrows," says Ramirez (New Scientist 10 Aug1996).
The flowering tops of Saint John's wort, Hypericum perforatum, are used in phytotherapy and cosmetology for their antiseptic and healing properties. They contain polycyclic quinones that are photodynamic sensitizers and antiviral agents. The plant also contains an anti-depressant which is likened to 'natural prozac'.
The Plant, the Drug: This perennial herb grows in the neglected fields and along the country roads of Europe and North America. It has small, opposite, and sessile leaves. The blade is dark green, scattered with transparent points, and has tiny black dots on the edges (pigment-filled cell clusters). The flowers, grouped in cymes, are easy to identify by their five, slightly asymmetrical, yellow petals, their numerous stamens fused into three bundles, and by three divergent dark-red styles. Drug identification may be difficult, due to the occurrence of hybrids and of multiple intermediate morphological types between H. perforatum and close species.
Chemical composition: The drug produces approximately 0.1% essential oil as well as n-alkanes, n-alkanols, triterpenes, and sterols. It is rich in phenolics: chlorogenic acid, epicatechin, and hyperforins. Flavonoids are abundant (4-5%): rutin, hyperin, isoquercitrin, and biflavonoids. The xanthone kielcorin has been isolated from the roots.
Saint John's wort has a reputation for having healing properties. The anti-bacterial properties of the extracts have been demonstrated in vitro. The same can be said of the properties of hyperforin, which is structurally quite close to the bacteriocidal keto-enols present in tile hop cone. The drug is said to exert, in humans, anti-depressant effects",which according to some authors, would be linked to MAO inhibiting activity. This activity, found in-vitro vitro on type A MAO, would be due not to hypericin (this was accepted based on tests published in 1984), but to fractions containing xanthones as yet unidentified. Hypericin is a photodynamic sensitizer, and is responsible for the accidents repeatedly observed in animals (it induces the formation of singlet oxygen). The most recent studies have shown substantial activity of hypericin on several retroviruses, in vitro and in vivo in the mouse, by a complex and apparently original mechanism. These findings, particularly the activity on the HIV-1 virus were at the origin of fair number of studies, including synthetic efforts; several patents have been applied for since 1990 (Bruneton 367).
In France, drugs based on the flowering tops of Saint John's wort may claim indications only for local treatment, as an emollient, itch-relieving trophic protective, for sunburns or burns, oral pain etc. These preparations must not be used before exposure to the sun.
Chemical Cornucopia
"FOR THE MOST PART, ANIMALS PROTECT AND sustain themselves through locomotion, while plants build up a variety of chemical substances for their stationary defense. Physiology has much to do with how plants and animals obtain food and the amounts of energy needed to secure their nutrition. Plants are adapted to consume sunshine for their energy and animals eat either plants or animals that eat plants. Thus light is the basic energy source for all living things on earth, but only plants are able to transform it into discrete substances, chemicals of varving complexity. Their dependence on available sunshine and water generally forces plants to live within a stricter energy budget than animals. To make the most of their method of survival, to use the energy available to them with the greatest efficiency, plants have evolved into chemical factories-sources of all sorts of raw and finished materials which people appropriate. Previous chapters have mentioned cellulose, the basic organic chemical from plants, and lignin, the material that impregnates the fibers and hardens them in wood and some other plant tissues. Oils of many kinds are made bv plants, from essential oils such as the attar of rose to the fatty oils such as cocoa butter. Sweet substances abound, from sugar cane and beet to palm jaggery and maple syrup. The dark and bitter seeds of the cacao pod are dispersed through a white pulp of intense sweetness, and some plants have chemicals which taste sweet but contain no sugar. The bitter parts of plants often contain alkaloids, complex nitrogenous compounds. Many of these produce marked physiological responses in higher animals and are thus of interest to medical researchers. The value of alkaloids to the plants themselves is debatable, but such potent chemical substances may be part of plants' defense mechanisms-their means of discouraging browsing animals. Thick skin or bark, spines, and thorns appear to serve a similar function. Common alkaloids in daily use all over the world include caffeine in tea and coffee and chocolate's theobromine-chemically almost identical to caffeine. Opiates from poppies and other narcotic producers, quinine from the bark of cinchona trees, digitalis from foxglove, and numerous others alkaloids find medical use. The white milk which drips from wounds on plants is called latex. Hevea brasiliensis and sapodilla (Manilkara zapota) plants yield a milk rich in chemicals called elastomers-chemicals which stretch. The former is known as rubber and the latter as chicle - the substance from which chewing gum originated. The boom in rubber as a major plantation crop in the late nineteenth and early twentieth centuries was due to its use in bicycle and automobile tires. During World War 11, after Pearl Harbor, supplies of Asian rubber were cut off, The search for alternative sources immediately gained high priority. According to Charles M. Wilson in his remarkable book from the war years, Trees and Test Tubes, The Story of Rubber, fuel rationing and the imposition of a strict 30 mile-per-hour speed limit in the United States were primarily to save rubber, not petroleum. Of the hundreds of plants that produce rubber, only a dozen or so are of commercial importance. With the exception of the Para rubber tree (Hevea brasiliensis), the most promising natural source of rubber today is Parthenium argentatum, the desert plant commonly known as guavule. Yet neoprene and other synthetics so captured the public imagination after the war that this natural product was almost totally neglected" (Ayensu et. al. 176).
"A member of the Compositae or daisy family, guayule grows wild in northern Mexico and the Big Bend area of southwestern Texas. Both hevea and guayule rubbers are identical in physical and chemical properties, the primary difference being that the latex hardens in the bark and wood of guayule stems. It was made into bouncy spheres by the ancient Aztec Indians for their ritual "basketball" games-with the latex extracted from the plants through a communal chewing of the stems. In 1980, the United States imported a quarter of the world's rubber supply from hevea plantations, most located in Indonesia, Malaysia, Thailand, Liberia, and Sri Lanka. At the same time, Mexico imported nearly 90 percent of its natural rubber. Research with superior breeding stock may help make guayule an economical crop. Mexico and the United States are working along these lines and pursuing improved techniques for the extraction of hardened latex. The federal governments of both countries, tire makers, and agricultural companies are seeking ways to commercialize guayule, a plant whose cultivation could be useful for and countries. Further research and development is required, however, before guayule can enter world markets. Natural rubber stands a good chance of holding its own in international trade, partly because latex is still essential for certain pneumatic tires. Those on airplanes are nearly pure natural rubber, as are many radials on large trucks since natural rubber can stand much higher temperatures than synthetics before disintegrating. In a form often called plantation crepe, Para rubber gives its famous bounce to fine casual and sports footware. The economics of rubber seem to be changing since petroleum, the chemical feedstock of synthetics, has grown far more expensive. As researchers look for substitutes, economics is dictating what appears to be a serious movement back to natural products. In terms of fuel for transport, Rudolf Diesel wrote in 1911: The diesel engine can be fed with vegetable oils and would help considerably if the development of-agriculture of'the countries which will use it. This may appear a futuristic dream but I can predict with great conviction that this use of the diesel engine may in the future be of great importance" (Ayensu et. al. 177).
"Oils in latex from plants in the daisy, spurge, and bean families are being investigated for use as alcohol fuel substitutes. A winner of the Nobel Prize for his investigation of the chemistry of photosynthesis, Professor Melvin Calvin of the University of California at Berkeley, has pursued the fuel oil potential of Euphorbia lathyris, called gopher weed in the United States where it is fairly common. This relative of spurges and poinsettias came from Europe where it is known as myrtle spurge and mole plant. Professor Calvin has obtained a vield from crushed plants equivalent to several barrels of hydrocarbons an acre, which could perhaps be improved through genetic selection of plants of high yield. E. lathyris produces a blend of carbon compounds known as terpene trimers. These, in turn, produce some substances almost identical to those derived from naphtha which cost approximately $50 per barrel in 1983. Even more spectacular is the copaiba of Amazonian Brazil, Copaifera lansdorfii, a leguminous tree whose trunk can be tapped to provide an oily sap used by local people as an anthelmintic, as well as an ointment for treating cuts, and a fuel for lamps. The trunk is drilled to tap the oil, and when the flow ceases the hole is closed with a wooden and clay plug. A diesel truck with no modification to the engine has run on the unprocessed sap. Further along toward commercialization is oil from the jojoba bush of American deserts, limited today to the cosmetics market because of its high price. Jojoba was first mentioned in print in 1789-the year in which the French Revolution began-in a book published in Venice, Italy. In his Storia Della California, the Mexican historian Francisco J. Clavijero reported that the jojoba shrub was held in great esteem bv the Indians of Baja California, who ate its fruit and used its oil to treat cancer and kidney disorders. A member of the boxwood family, Buxaceae, jojoba is known to science as Simiiiondsia chinensis, although it does not occur in China as suggested by the species name. Its home ground is the Sonora Desert of Mexico, Arizona, and southern California, where summer temperatures can reach 115' F in the shade. An evergreen shrub with leathery leaves, a deep root system, and a tolerance for saline and alkaline soils, jojoba can grow to a height of more than ten feet. Unique in the Plant Kingdom, its olive-sized seeds contain a liquid wax rather than the commonly found fat or oil. Chemically, it is identical to oil of the sperm whale. By hydrogenation, the catalytic process that creates margarine from vegetable oil, the jojoba product emerges as a hard white solid. Until recently the whale's liquid wax has had no peer as a lubricant in automobile transmissions and other precision machinery subjected to high pressure and temperature. Jojoba seeds contain half their weight in a raw material which needs little refining to be used as a lubricant. In technical terms, its viscosity, flash point, and fire point resemble those of sperm oil. It is without odor and taste, and is not damaged when heated repeatedly to high temperatures. This means that jojoba is probablv suitable for everything done by sperm oil and much more. This includes an amazing potential for the cosmetics industry as a component of hair oil, soap, shampoo, face creams, moisturizers, sunscreen compounds, and various conditioners" (Ayensu et. al. 180).
"With all their oily, waxy, and aromatic juices, saps, and oozes, plants are natural sources of ncw insecticides and pesticides, additions to the traditional arsenal of tobacco derivatives, pyrethrum and rotenone plant products. Scientists of the University of California at Berkeley are investigating chemicals produced bv an African bugleweed (Ajuga remota) of the mint family. Its chemical extracts interfere with molting of cotton pests such as the pink boll-worm and the fall armyworm. The plant is used bv African herbalists to combat high blood pressure and malaria, but the Berkeley scientists found that it will literally cause the caterpillars to starve inside their own repeatedly molted skins. Usually the old skins break open and are shed, but not after applications of Al'uga. Ways are now being investigated to obtain larger amounts of the bugleweed chemical, ajugarin. The neem tree (Azadirachta indica), a member of the mahogany wood family, is also showing promise as a source of natural insecticide. Native to India and most common in the dry Deccan forest, it yields timber, gum, astringent bark, and various medicines. Indian farmers and merchants add neem to stored grain to prevent insect damage. Even when ground into flour or meal, and thus eaten with the grain, neem has not been found harmful to people. From its roots to its trunk, bark, leaves, flowers, fruit, and seeds, almost every part of the plant is put to use in the countries where it is grown. Neem's natural insecticides, mainly azadii-achtin and related compounds, are concentrated in the seed and released by grinding. Applied in suspension to a crop, the compounds penetrate each plant's vascular system and are thereby spread, repelling attacking insects. Fortunately, azadirachtin and other repellent compounds reach into newlv developing leaves and branches. Neem deters a truly amazing catalog of insect pests: desert locust, tobacco budworm, cotton stainer, and fall armyworm; beetle and moth pests of stored grain. Japanese beetles will not even touch a treated plant. There are many others including the lowly housefly. Trials are being carried out with neem constituents for pest control in the United States. Tests are also underway to investigate neem's ability to become established in hot dry regions without native timber. Neem may also improve the soil. Already grown extensively as a shade and lumber tree in arid and semi-arid tropical areas of Africa and other regions of the Old World, it is being introduced, though quite slowly, into the Western Hemisphere-primarilv in Puerto Rico, the Virgin Islands, and Haiti - where it has been a street tree since the 1960s. Its world cultivation is somewhat uneven; in 1981 there were approximately 25 million neem trees in India, and only two in the United States, both in Miami. A chemical from endod (Phvtolacca dodecaildra), an African plant related to the American pokeweed, may help free the human race from one of its great afflictions. As many as two hundred million people harbor the tiny blood flukes which cause schistosomiasis or bilharzia. These parasites are passed to unaffected people who bathe in the same streams used bv those with the disease. Water snails harbor the flat-worms which gain entrance to the human body bv burrowing into the skin. Distress, damage to internal organs, and death mav occur. The ability of the endod plant to kill water snails was noted by scientists in Ethiopia. To wash their clothes, rural people go to nearby streams and use the endod, a pokeberry, as their detergent. Water downstream is free of snails. Local cultivation could supply the chemical to communities unable to buy commercial pesticides. Throughout the world, in rural areas as well as in large cities, many potentially useful plant chemicals either poison or addict their users. Other substances, those derived from mushrooms, find ethnic or religious use, as with various hallucinogens employed for tribal rituals in the Americas and elsewhere. The coca plant (E throxylum coca) from Andean nations and the opium poppy (Papaver somniferum), have an illegal following in virtually every country on earth. Only since the 1970s have scientists begun to understand and to attempt detailed explanations of the various forms of chemical intoxication. The following pages reveal surprising facts about the non-medical uses of plant substances, often toxic, that have become part of the culture of two societies" (Ayensu et. al. 181).
Medicines are also in Animals and Fungi
Important biochemicals are not confined to plants, they also occur in aminals and fungi. There is more diversity in insects than any other group and they are being increasingly explored for medicinal value, especially since they have elaborate defence mechanisms against both plant toxins and predators. Likewise many antibiotics come from primitive microorganisms, just as penicillin came from the penicillium mould. Likewise frogs, toads, fish and toadstools are renowed for toxins, stings and pooisons which often have significant medicinal value.
Chinese Herbal Medicine and Biodiversity
Suspended Animation
Animal Cures
New Scientist 13 july, 1996 A CHINESE herbal medicine could avert a health disaster in sub-Saharan Africa, as quinine-resistant malaria threatens the continent.
Two new studies have found that the medicine, known as artemether, can treat the disease. But millions may still die because they cannot afford to pay for it. Malaria can be treated with a range of drugs if it is caught early. Later on, when the malaria parasite becomes established in the blood-stream, infected red blood cells can block blood vessels in the brain, leading to coma and death. For years, the only really effective treatment for cerebral malaria was quinine, which is derived from the bark of the chinchona tree. But in the past few years, forms of the malaria parasite that are not affected by quinine have emerged in Southeast Asia. Artemether came along just in time. "In Cambodia we were in danger of soon approaching the point of having no drugs to treat cerebral malaria with," says Brian Greenwood of the London School of Hygiene and Tropical Medicine. The fear now is that quinine resistance will spread to Africa, where 90 per cent of the world's cases of cerebral malaria occur. Already, 2.7 million Africans die each year from malaria, and that figure could rise to almost 7 million if quinine resistance spreads from Southeast Asia. "It's a terrifying thought," says Greenwood. In general, new forms of drug resistance take about five years to reach Africa from Asia. The two studies suggest that artemether, which is derived from the shrub wormwood, could save Africa from a malaria catastrophe. They show that artemether was as effective as quinine against cerebral malaria among adults in Asia. Already, the researchers predict that thousands of lives could be saved each year in Southeast Asia by replacing quinine with artemether. "This is the first time it's been shown that this drug is effective against severe cerebral malaria. It's very good news," says Greenwood. "This family of drugs represents a major ad vance in the treatment of malaria," says White. "With declining pharmaceuticals company interest in developing drugs to treat tropical disease, we're very fortunate nature had given us such an effective drug."
Olliaro says that drugs firms have been slow to develop artemether, because they cannot apply for patents on a drug that is already used in traditional Chinese medicine and has been described in the scientific literature. This means that no company can have the monopoly that would guarantee them a healthy profit. The overall cost of artemether treatment is comparable with quinine, which requires monitoring of blood sugar levels to check for side effects. But the drug itself costs twice as much. This is a problem, says Olliaro, because drugs must be paid for by patients or their families in many African countries. Another shrub wormwood extract called arteether is currently being developed by the TDR and a Dutch company called Artecef. "We are hoping that the drug might be registered in 1998 and the cost will be low," says Olliaro.
Hawaiian plant could fight TB 18
December, 2000
Tuberculosis bacteria: vulnerable to traditional cure By the BBC's John Duce
Scientists believe they have found a significant new lead in the fight against one of the world's biggest killers, tuberculosis.
They say that extracts from a plant used as a folk remedy in various parts of the world kill TB bacteria and could be the basis of a new drug.
About two million people a year die from tuberculosis and researchers say new ways of tackling the disease are urgently needed as drug-resistant strains of the bacteria develop.
A team headed by Jonel Saludes, a researcher formerly based at the University of Santo Tomas in Manila in the Philippines, has been studying a plant known as 'Noni' in Hawaii, or Morinda citrofolia, to give it its scientific name.
It is used in various places around the world as a folk remedy to fight numerous ailments and the researchers have been able to isolate chemical compounds which they say appear remarkably effective at killing TB bacteria under laboratory conditions.
Preliminary results
The scientists stress their research is at a very early stage and any potential side-effects on people are unknown, but they hope their findings will ultimately lead to the development of a new drug.
Tuberculosis is an airborne, infectious disease, in which bacteria infect the lungs and other areas of the body.
Medicines are available to fight TB, but drug-resistant strains of the bacteria are developing, hastening the need for alternate remedies.
Most people killed by tuberculosis live in South East Asia and sub-Saharan Africa, but the World Health Organisation (WHO) says new outbreaks have begun to occur in Eastern Europe after almost 40 years of steady falls in the number of infections.
The WHO says people with HIV are particularly at risk of dying from the disease because their immune systems are so weak.
Andes Flower is Champion Pest Killer Andy Coghlan New Scientist 20 Jan 1996
HIGH ON the slopes of the Andes grows a delicate yellow-flowered plant that could be the answer to a farmer's prayers. The plant, Calceolaria andiria, contains two chemicals that kill sapsucking insects such as aphids and whitefly, even those that have grown resistant to most modern insecticides. Farmers spend around $1 billion each year trying to fend off sapsuckers. The potent killing power of the two conipouilds, called naplithoquinones, was discovered during an international research programme to screen wild plants for potential new insecticides. The good news for farmers is that the compounds kill the notorious "B-biotype" of the tobacco whitefly, Beniisia tabaci. As this insect has spread across the world, it has acquired resistance to most common pesticides. Apart from the physical damage they inflict on plants, whitefly often inject viruses into their host as they feed. The B-biotype attacks some 600 species of plant around the world, including important crops such as cotton. It multiplies five times as fast as other strains of B. tabaci, and transmits up to 60 viruses that cause a host of diseases. The naphthoquinones also kill other sucking pests that have grown resistant to pesticides, including the spotted spider Mite, Tetratlyclius urticae, and the peach potato aphid, Myzus persicae. Hermann Niemeyer and his colleagues from the Laboratory of Ecological Chemistry at the University of Chile in Santiago collected some 400 species of plants from the slopes of the Chilean Andes. They sent extracts from the plants to the University of Southampton's Agrochemical Evaluation Unit, where they were tested for any activity against pests. The team at Southainptoii then sent the 20 most proniising extracts for further analysis at the Institute of Arable Crops Research at Rothamsted in Hertfordshire. At Rothamsted, John Pickett, Bhupinder Khambay and their colleagues took just a week to isolate the naphthoquinones and show them to be the most active comPonents in extracts of Calceolaria. "They are very easy to extract, and account for 5 per cent oi the dry weight of the plant," says Khanibay. The world's most insecticide-resistant ,whitefly, aphids and mites died within minutes of being exposed to either of the compounds. "We don't kilow tile mode action yet, but both compounds are extremely active," says Khambay. By establishing how the compounds kill the pests, the Rothamsted team hopes to avoid the problems of resistance that follow the indiscriminate use of chemical pesticides. "If we know how they work, we can influence the way these compounds will be used," says Khambay. Pickett and Khambay are also tinkering with the structures - which are very simple chemically - to try to develop synthetic variants that are even more potent. In another part of the programme, at the Royal Botanic Gardens , Kew, Monique Simmonds and her team are investigating the potential for growing Candina as a source of naphthoquinones in Britain. They are also analysing tissue from relatives of Candina that already grow in temperate climates to see if they also produce the compounds. Another option, says Simmonds, might be to grow plants that make compounds that are easily converted into the naphthoquinones. The raw dye henna, for example, is a potential starting compound from which to make them and Lawsonia ineris, the source of henna, is already grown widely as a crop in North Africa. Early investigations at Kew and Rothamsted suggest that the naphthoquinones are harmless to beneficial insects such as ladybirds. Khambay also expects the compounds to decay quickly in soil, probably disappearing within weeks. The British Technology Group, which patents and licenses inventions, has patented the naphthoquinones. It is negotiating with agrochemicals companies to develop the compounds as commercial insecticides. The BTG hopes that within five to seven years, the compounds will be as successful commercially as pyrethrin insecticides. These compounds, developed at Rotliamsted from chrysanthemum daisies, have been big money -spinners. Any profits from sales of the new naphthoquinones will be split between the collaborators, including the researchers in Chile who first collected the plants.