Herbalism is a traditional medicinal or folk medicine practice based on the use of plants and plant extracts. Herbalism is also known as botanical medicine, medical herbalism, herbal medicine, herbology, and phytotherapy. Sometimes the scope of herbal medicine is extended to include fungi and bee products, as well as minerals, shells and certain animal parts.

Many plants synthesize substances that are useful to the maintenance of health in humans and other animals. These include aromatic substances, most of which are phenols or their oxygen-substituted derivatives such as tannins. Many are secondary metabolites, of which at least 12,000 have been isolated — a number estimated to be less than 10% of the total. In many cases, these substances (particularly the alkaloids) serve as plant defense mechanisms against predation by microorganisms, insects, and herbivores. Many of the herbs and spices used by humans to season food yield useful medicinal compounds.

All plants produce chemical compounds as part of their normal metabolic activities. These include primary metabolites, such as sugars and fats, found in all plants, and secondary metabolites found in a smaller range of plants, some useful ones found only in a particular genus or species. Pigments harvest light, protect the organism from radiation and display colors to attract pollinators. Many common weeds have medicinal properties.

The functions of secondary metabolites are varied. For example, some secondary metabolites are toxins used to deter predation, and others are pheromones used to attract insects for pollination. Phytoalexins protect against bacterial and fungal attacks. Allelochemicals inhibit rival plants that are competing for soil and light.

Plants upregulate and downregulate their biochemical paths in response to the local mix of herbivores, pollinators and microorganisms.The chemical profile of a single plant may vary over time as it reacts to changing conditions. It is the secondary metabolites and pigments that can have therapeutic actions in humans and which can be refined to produce drugs.

Plants synthesize a bewildering variety of phytochemicals but most are derivatives of a few biochemical motifs.

Thursday 22 May 2008

ALOE VERA


Introduction
This fact sheet provides basic information about aloe vera—common names, uses, potential side effects, and resources for more information. Aloe vera's use can be traced back 6,000 years to early Egypt, where the plant was depicted on stone carvings. Known as the "plant of immortality," aloe was presented as a burial gift to deceased pharaohs.

Common Names—aloe vera, aloe, burn plant, lily of the desert, elephant's gall, lidah buaya
Latin Names—Aloe vera, Aloe barbadensis


What It Is Used For
Traditionally, aloe was used topically to heal wounds and for various skin conditions, and orally as a laxative. Today, in addition to traditional uses, people take aloe orally to treat a variety
of conditions, including diabetes, asthma, epilepsy, and osteoarthritis. People use aloe topically for osteoarthritis, burns, and sunburns. Aloe vera gel can be found in hundreds of skin products, including lotions and sunblocks. The Food and Drug Administration (FDA) has approved aloe vera as a natural food flavoring.

How It Is Used
Aloe leaves contain a clear gel that is often used as a topical ointment.
The green part of the leaf that surrounds the gel can be used to produce a juice or a dried substance (called latex) that is taken by mouth.

What the Science Says
Aloe latex contains strong laxative compounds. Products made with various components of aloe (aloin, aloe-emodin, and barbaloin) were at one time regulated by the FDA as oral over-the-counter (OTC) laxatives. In 2002, the FDA required that all OTC aloe laxative products be removed from the U.S. market or reformulated because the companies that manufactured them did not provide the necessary safety data. Early studies show that topical aloe gel may help heal burns and abrasions. One study, however, showed that aloe gel inhibits healing of deep surgical wounds. Aloe gel does not prevent burns from radiation therapy. There is not enough scientific evidence to support aloe vera for any of its other uses.

Side Effects and Cautions
Use of topical aloe vera is not associated with significant side effects. Abdominal cramps and diarrhea have been reported with oral use of aloe vera. Diarrhea, caused by the laxative effect of oral aloe vera, can decrease the absorption of many drugs.
People with diabetes who use glucose-lowering medication should be cautious if also taking aloe by mouth because preliminary studies suggest aloe may lower blood glucose levels.
Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.

Sources
Aloe. Natural Medicines Comprehensive Database Web site. June 5, 2007.
Aloe (Aloe vera). Natural Standard Database Web site. Accessed on June 3, 2007.

For More Information
"What's in the Bottle? An Introduction to Dietary Supplements"
"Herbal Supplements: Consider Safety, Too"
NCCAM Clearinghouse

The NCCAM Clearinghouse provides information on CAM and NCCAM, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

Posted by AGID at 05:36

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