To date, only 7 percent of all tropical plants have been tested for potential usefulness to humans. The rainforests have already given us medicines such as hydrocortisone, which is used to treat inflammation, rhematoid arthritis, and rheumatic fever. A special class of plant-derived compounds known as the alkaolids, which are organic compounds that contain nitrogen, have been found to be twice as frequent in tropical plants, than plants found in the temperate zones. As of 1988, the 10,000 known alkaloids have been used by the pharmaceutical industry as cardiac and respiratory stimulants, blood pressure boosters, anesthetics, painkillers, muscle relaxants, and many other applications.
Many of the medicines that are familiar to us today, were first used by tribal people. Scientists often seek the help of natives when searching for plants with medicinal qualities, because of the vast knowledge that the natives pocess.
The Gayo hill people in Sumatra, for example, use a plant called Parkia roxburghii to releave headaches. They prepare this plant by crushing and roasting its seeds. This plant also has the ability to kill parasitc worms, help cuts heal faster, and treat colic.
A group of tribal people in South America often prepare a black sticky substance called curare from the resin of a rainforest liana, Chondodendron tomentosum. When hunting, The natives then use this substance on arrow tips. If the arrows pierces the skin of the hunted animal, the animal is paralyzed. Alkaloids from this vine are used to treat spams caused by tetanus and are used to relax muscles during abdominal or heart surgery.
Indians once used the mexican barbasco vine as a fish poison, by crushing barbasco yams and pouring them into the river. The paralyzed fish would then float to the surface. When scientists examined this plant they discovered a chemcial called disogenin, which has been used as the active incredient in birth ccontrol pills. This same vine is used to produce hydrocortisone.