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Pharmacognosy is a term invented about 200 years ago which categorized plants used for medicinal purposes. Scientists today define pharmacognosy as Ōthe study of the physical, chemical, biochemical and biological properties of drugs, drug substances, or potential drugs or drug substances of natural originĶ (Balunas). As practiced today, pharmacognosy involves the study of natural products to possibly discover new chemical compounds located in these plants that can lead to new remedies and medicines.
A wide variety of plant parts are used for medicinal purposes. The fleshy or woody roots of some plants are used, such as the DevilÕs claw. Another part that is often used is the Rhizome, which is the part of the stem that grows just below the ground (Blythe). Ginger is a common plant in which the Rhizome is used. Bulbs of other plants are used, such as the bulb of the garlic plant. Bark is the most common part of the plant used, as it contains most of the medicinal ingredients (Blythe). The bark of the cinnamon plant is one example. Wood, which is similar to bark, is also used for medicinal purposes. Sandalwood, one example, is used as both a skin moisturizer and to combat insomnia (Gurib-Fakeem). Leaves can be eaten or crushed into a liquid, as in the Gingko plant. Flowers in plants such as the Camomille are used as well. Fruits and seeds are also some common forms used. The berries from the Saw Palmetto, which can be found in Florida, are used to treat urinary problems (Gurib-Fakeem). The indigenous people of Florida crushed the berries and drank the resulting juice. Obviously, the medicinal aspects of the plants can be found everywhere and anywhere. Once the correct plant part is harvested and the medicinal aspect is isolated, it is administered either orally, topically, intravenously, or sniffed through the nose.
Tropical plants are used for all kinds of ailments. There are over 120,000 medicinal plants that have been discovered (Balunas). Because of this huge number, I am only going to describe some of the most common plants and their functions in medicine.
Treatment of diseases
Many tropical plants treat and help cure a wide variety of diseases. For example, Cranberry juice as well as the Saw Palmetto help to reduce bladder infections. Also, forms of garlic are used to treat asthma and bronchitis (Garib-Fakeem).
Increase the quality of life
Many plants just generally help to better bodily systems. For example, Ginkgo reduces capillary fragility, which basically means it increases the quality of blood. The Purple Coneflower is used to stimulate white blood cells in the blood. And St. JohnÕs Wort is a common treatment for depression (Garib-Fakeem).
Treatment for Cancer
Almost half of the drugs used to treat cancer are plant based. One of the most significant anti-cancerous plants discovered is the Madagascan Periwinkle. Alkaloids present in this plant are effective against childhood leukemia, breast cancer, and HodgkinÕs disease (Balunas).
Some plants help to manage diabetes. Garlic and Aloe Vera are a few examples (Garib-Fakeem).
Plants from all over the world, including India, South Africa, South America, Japan, and the Caribbean, are used in medical treatments. The majority of these plants are found in tropical areas like the rainforests of Central and South America. This is primarily because of the incredible diversity of plants found in these areas. More than half of the world's estimated 10 million species of plants, animals, and insects live in the tropical rainforests. And currently, 121 prescription drugs sold worldwide derive from tropical plants of the rainforests (Shanley). That is just prescription drugs; there are many more over-the-counter drugs and herbs sold that come from plant sources as well.
Costa Rica is home to one of the largest rainforests in the world. Some common plants found in this country that are used medically include garlic, Aloe Vera, Wormwood, black and green tea, Madagascan Periwinkle, and Motherwort.The leaves of the green tea plant are crushed, mixed with water, and drank. Anti-carcinogenic components of this plant, as well as with the black tea plant, have been proven to prevent cancer. Polyphenols found in the plant block the formation of many cancer causing compounds and detoxify carcinogens. This plant may also exert an estrogen blocking effect that helps prevent breast and uterine cancer. Green tea also helps control blood cholesterol, high blood pressure and blood sugar levels, and even fights dental cavities(Gurib-Fakeem).
Wormwood is used as an insect repellant, as a sedative, to reduce fever, and to expel parasitic worms (Gurib-Fakeem).
Aloe Vera is a plant that is commonly used for many different treatments all over the world. Most Aloe products are made from the gel on the inside of the plant and are either taken orally or topically. This gel contains 75 nutrients, 20 minerals, 18 amino acids, and 12 vitamins (Balunas). As discussed earlier, Aloe Vera as well as garlic help to control diabetes. Aloe also as heals skin wounds and boosts the immune system. Because of this last factor, Aloe Vera is a possible treatment for cancer and HIV/AIDS. The National Cancer Institute has included Aloe Vera in their recommendations for increased testing because of these apparent cancer fighting properties. Taken orally, aloe also appears to work on heartburn, arthritis, asthma, and lowers blood sugar levels in diabetics. It also appears to work on congestion, intestinal worms, indigestion, stomach ulcers, colitis, hemorrhoids, liver problems such as cirrhosis and hepatitis, kidney infections, urinary tract infections, prostate problems, and as a general detoxifier (Medicinal plants in Costa Rica).
The Madagascan, or Rosy Periwinkle is another common plant found in Costa Rica. This plant is used in traditional medicine against diabetes. The extracts of the leaves are combined with water and taken orally (Gurib-Fakeem).
Motherwort is used to counteract PMS, menstrual pain, and delayed menstruation. It is also known to strengthen the heart and so is frequently prescribed for heart palpitations. Motherwort is usually made into a tea form and taken orally (Balunas).
The main fascination many people have with the tropical plants of the rainforests is not what they have proven to be able to do, but what we donÕt yet know that they can do. Many scientists believe there are still undiscovered species of plants in places like Costa Rica that have the cure for cancer. There are already several drugs that have been found in plants that treat cancer. In the 1970s, a tremendous breakthrough in cancer studies was made with the Madagascan Periwinkle, a plant found in Costa Rica. Alkaloidal compounds found in this plant have been proven to be effective against leukemia, breast cancer, and HodgkinÕs disease (Gurib-Fakeem). Other plants with possible anti-cancerous compounds include Mayapple, used to treat skin cancer, the Pacific Yew tree, used to stop the growth of tumors, and the Xi Shu, used to fight against Leukemia (Balunas). Knowing that these discovered species have been proven to help treat cancer, it is unimaginable the amount of undiscovered species in the rainforests that have the possibility of doing even more.
AIDS treatment is another topic that has been on the minds of scientists. Many believe that there are species of plants in the rainforests that can treat or even fully cure HIV and AIDS. Currently there are a few identified plants that are known to be able to treat AIDS. Since there is no known cure for AIDS yet, there are several drugs used to slow the progression of the viral infection. One of the most hopeful anti-AIDS compounds is the Malasian tree. Compounds found in this tree, such as Calanolide A, have shown anti-HIV activity in several experiments on animals. These components are in the process of being tested in human trials (Gurib-Fakeem). The Madagascan Periwinkle, discussed earlier and found in Costa Rica, is a plant that may have anti-HIV components. An anti-cancer alkaloid in this plant disrupts the spindle fibers that separate chromosomes during cell division. This could be useful in fighting KaposiÕs sarcoma, which is a type of skin disease associated with AIDS (Gurib-Fakeem). Some other tropical plants that have anti-HIV components include the Mamala and the woody vine Ancistrocladus, found in Africa (Balunas).
Tragically, rainforests once covered 14% of the earth's land surface; now they cover only 6% (Shanley). Unbelievably, over 200,000 acres of rainforest are burned every day in the world to make room for farming and housing. That is over 150 acres lost every minute of every day. Experts estimate that at the current rate of destruction, the last remaining rainforests could be consumed in less than 40 years. Experts also estimate that we are losing 130 species of plants, animals and insects every single day as they become extinct from the loss of rainforest land and habitats (Cubie). Costa Rica itself has already lost a great deal of its forest and about 3% of what is left disappears every year (Medicinal Plants in Costa Rica). This is the highest rate in Central America apart from El Salvador. Much of this rainforest loss also comes from scientists and biologists harvesting tropical plants to be used or experimented with for medical purposes. In fact, today's 20 best-selling drugs, which are worth about $6 billion a year, are derived from tropical plants (Balunas). Drug companies can make tens of millions of dollars from the profit of a new compound. As a result, these companies are paying millions of dollars just to find new species of plants that can be used and sold for medical purposes. Because of this, rare plants are being taken from the tropics at an alarming rate. There must be a better way to safely extract these medicinal plants without threatening their existence.
A continuing problem associated with medicinal plants is the regulation of their use. For most of these plants, there is nothing regulating how much or how little of the plant is used in the product sold. For example, some skin products sold that contain Aloe Vera only have 1% or less Aloe in the lotion (Royal). This low amount of Aloe is not going to have much effect. But there is nothing the buyer can do about this, since there are no laws the seller has to follow. Also, these plants and herbs do not qualify as a food or a drug, so they donÕt have to follow any sort of standard to be sold to the public. Therefore, if a certain compound found in a plant has unwanted side effects, the seller has no responsibility to put this on their label or inform the buyer about this side effect in an way. This can be very detrimental to individuals taking something like wormwood, for example, because if taken in excess, this plant can cause hallucinations. To solve this problem, the government needs to create an administration solely to regulate the amount and frequency of use of medicinal plants and herbs. They could even create a new branch of the FDA that deals with this issue. If this was done, consumers wonÕt have to question the amount of treatment they are actually receiving.
There are an incredible amount of benefits that can come from the use of medicinal plants. They are used to treat everything from menstrual cramps to skin cancer. A great majority of these plants are found in the rainforests of Central and South America, which is one reason to preserve what little rainforest we have left. If we take action to regulate the sales of these plants, as well as preserve the areas in which they thrive, the opportunities for new cures and treatments and a better livelihood for all will be endless.
Gurib-Fakim, Ameenah. "Medicinal Plants: Traditions of Yesterday and Drugs of Tomorrow." Molecular aspects of Medicine. Feb 2006. Vol 27, Issue 1. P.1-93.
Balunas, Marcy J. "Drug Discovery from Medicinal Plants." Life Sciences. Dec 2005. Vol 78, Issue 5. P.431-441.
Cubie, Doreen. "A 'Green' Threat to Plants." Wildlife Conservation. Jul/Aug 2003. Vol 106, Issue 4. P. 14.
Shanley, Patricia. "The Impacts of Forest Degradation on Medicinal Plant Use." Bioscience. Jun 2003. Vol 53, Issue 6. P.573-585.
Royal, Dentinee-Charisse. "Nature's Ailing Medicine." Mother Earth News. Feb/Mar 2000. Issue 176, p.12
"Medicinal Plants in Costa Rica." American Botanical Council. Online. http://www.herbalgram.org. Accessed March 10, 2006.
Blythe, Shephen. "An Introduction to Medicines from Plants." Online. http://www.rainforesteducation.com. Accessed March 10, 2006.
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