Plants range in size from 0.5 microns to 175 meters in length to
hundreds of tons in weight. Rates of plant growth can vary from minutes
to years. Plants are some of the most diverse and intriguing of all
organisms on this planet. They are needed to keep us alive; they produce
much of the oxygen in the atmosphere; they relieve pain and they cause
much pain. This discussion of plants and their medicinal purposes can
develop into a provocative discussion on drugs because a large amount of
drugs or their synthetic derivatives come from plants.
The early interest in plants was probably due to use of plants
materials for the treatment of human ills or for pleasure. Records show
that plants played an important part in early western and eastern
civilizations. Although today, chemists have been able to make synthetic
drugs that mirror the effects of natural plants there are many plants
that are still used. Belladonna, opium, psyllium, rhubarb, eucalyptus,
licorice, nux vomica, and cinchona, are the sources of the important
alkaloids, atropine, morphine, strychnine, and quinine respectively.
Digitalis, a drug used for certain heart disorders, and used by many
people, is derived from a plant. The most common drug obtained from
plants is caffeine. Caffeine can be found in seeds (coffee, cocoa,
cola), leaves (tea, mate (leaves from holly), yaupon, and bark (yoco).
Historically caffeine has been used in most civilizations.
Drugs are usually taken because they give the user a feeling of
euphoria. Euphoria is a feeling of general well-being. Hypnotics are
drugs that cloud reasoning, consciousness, and though. Excitants, or
stimulants, cause one’s body to be stimulated into a faster heartbeat
and a faster metabolic rate. Hallucinogens cause people to see, hear, or
feel sensations that are not real.
Two commonly used stimulant drugs are tobacco and caffeine. Hypnotics
include mescaline (mushrooms). Hallucinogens include peyote, agaric,
marijuana, and morning glory. Euphorics include coca (rich in cocaine)
and opium (morphine, codeine). These drugs can be useful to doctors
because many relieve symptoms or pain of diseases. However, if misused,
drugs can become harmful to one’s body and general health.