Role of herbal medicine in human society

People on all continents have used hundreds to thousands of indigenous plants for treatment of ailments since prehistoric times[History of Plants in Medicine.]. There is evidence from the Shanidar Cave in Iraq that suggests Neanderthals living 60,000 years ago used medicinal plants. A body that was unearthed there had been buried with eight species of plants which are still widely used in ethnomedicine around the world.[Medicinal plants in a Middle Paleolithic grave Shanidar IV?, Lietava J., J Ethnopharmacol. 1992 Jan;35(3):263-6., PMID 1548898]
The first generally accepted use of plants as healing agents was depicted in the cave paintings discovered in the Lascaux caves in France, which have been radiocarbon-dated to between 13,000-25,000 BCE. Medicinal herbs were found in the personal effects of an "Ice man," whose body was frozen in the Swiss Alps for more than 5,300 years, which appear to have been used to treat the parasites found in his intestines.[5300 years ago, the Ice Man used natural laxatives and antibiotics, Capasso L., Lancet. 1998;352:1864, PMID 9851424.]
Anthropologists theorize that animals evolved a tendency to seek out bitter plant parts in response to illness.[The evolution of herbal medicine: behavioral perspectives.] This behavior arose because bitterness is an indicator of secondary metabolites. The risk benefit ratio favored animals and protohumans that were inclined to experiment in times of sickness. Over time, and with insight, instinct, and trial-and-error, a base of knowledge would have been acquired within early tribal communities[http:www.clas.ufl.edu/users/mattjp/Lecture%20Notes/Medicinal%20Plants.doc Medicinal Plants.] As this knowledge base expanded over the generations, the specialized role of the herbalist emerged. The process would likely have occurred in varying manners within a wide diversity of cultures.
Indigenous healers often claim to have learned by observing that sick animals change their food preferences to nibble at bitter herbs they would normally reject[Huffman MA (May 2003). "Animal self-medication and ethno-medicine: exploration and exploitation of the medicinal properties of plants.". Proc Nutr Soc 62 (2): 371-81. PMID 14506884.][citation needed]. Field biologists have provided corroborating evidence based on observation of diverse species, such as chimpanzees, chickens, sheep and butterflies. Lowland gorillas take 90% of their diet from the fruits of Aframomum melegueta, a relative of the ginger plant, that is a potent antimicrobial and apparently keeps shigellosis and similar infections at bay.[a b Wild Health: How Animals Keep Themselves Well and What We Can Learn From Them, Cindy Engel, Houghton Mifflin, 2002]
Researchers from Ohio Wesleyan University found that some birds select nesting material rich in antimicrobial agents which protect their young from harmful bacteria[Jan Ichida, Proceedings of the 104th General Meeting of the American Society for Microbiology. reported in Birds use herbs to protect their nests, BJS, Science Blog, Wed, 2004-05-26].
Sick animals tend to forage plants rich in secondary metabolites, such as tannins and alkaloids[Hutchings MR, Athanasiadou S, Kyriazakis I, Gordon IJ (May 2003). "Can animals use foraging behavior to combat parasites?". Proc Nutr Soc. 62 (2): 361. PMID 14506883.][citation needed]. Since these phytochemicals often have antiviral, antibacterial, antifungal and antihelminthic properties, a plausible case can be made for self-medication by animals in the wild.[a b Wild Health: How Animals Keep Themselves Well and What We Can Learn From Them, Cindy Engel, Houghton Mifflin, 2002]
Some animals have digestive systems especially adapted to cope with certain plant toxins. For example, the koala can live on the leaves and shoots of the eucalyptus, a plant that is dangerous to most animals. [Phascolarctos cinereus.]A plant that is harmless to a particular animal may not be safe for humans to ingest[Take Time to Identify Toxic Plants to Keep Your Family and Pets Safe.][citation needed]. A reasonable conjecture is that these discoveries were traditionally collected by the medicine people of indigenous tribes, who then passed on safety information and cautions.
The use of herbs to treat disease is almost universal among non-industrialized societies[citation needed]. A number of traditions came to dominate the practice of herbal medicine at the end of the twentieth century:
-The herbal medicine system, based on Greek and Roman sources -The Ayurvedic medicine system from India -Chinese herbal medicine (Chinese herbology) -Unani-Tibb medicine -Shamanic Herbalism Many of the pharmaceuticals currently available to physicians have a long history of use as herbal remedies, including opium, aspirin, digitalis, and quinine. The World Health Organization (WHO) estimates that 80 percent of the world's population presently uses herbal medicine for some aspect of primary health care. [Traditional medicine.]Herbal medicine is a major component in all traditional medicine systems, and a common element in Ayurvedic, homeopathic, naturopathic, traditional Chinese medicine, and Native American medicine.
According to the WHO, 74% of 119 modern plant-derived pharmaceutical medicines are used in ways that are similar to their traditional uses. Major pharmaceutical companies are currently conducting extensive research on plant materials gathered from the rainforests and other places for possible new pharmaceuticals.[Introduction, Herbal Medicine, holisticonline.com]
The use of, and search for, drugs and dietary supplements derived from plants have accelerated in recent years. Pharmacologists, microbiologists, botanists, and natural-products chemists are combing the Earth for phytochemicals and leads that could be developed for treatment of various diseases. In fact, approximately 25% of modern drugs used in the United States have been derived from plants.
-Three quarters of plants that provide active ingredients for prescription drugs came to the attention of researchers because of their use in traditional medicine. -Among the 120 active compounds currently isolated from the higher plants and widely used in modern medicine today, 75 percent show a positive correlation between their modern therapeutic use and the traditional use of the plants from which they are derived. -More than two thirds of the world's plant species - at least 35,000 of which are estimated to have medicinal value - come from the developing countries. -At least 7,000 medical compounds in the modern pharmacopoeia are derived from plants[Learning from Indigenous People, Faezah Ismael, ASEAN Review of Biodiversity & Environmental Conservation, MacArthur Foundation, Wednesday, March 14, 2001]